Abstract:
The invention relates to a three-phase boost rectifier circuit and a control method thereof, and an uninterrupted power supply, which contains at least first battery packs BAT+, second battery packs BAT−, and a boost rectifier module; the boost rectifier module comprises a first bidirectional thyristor SCR 1,  a second bidirectional thyristor SCR 2,  a third bidirectional thyristor SCR 3,  a fourth bidirectional thyristor SCR 6,  a first unidirectional thyristor SCR 4,  a second unidirectional thyristor SCR 5,  a first inductor L 1,  a second inductor L 2,  a third inductor L 3,  a three-phase fully controlled rectifier bridge, a first capacitor C 1  and a second capacitor C 2.  The invention can ensure the balance of positive and negative bus&#39;s voltage without the balancing device under battery operated boost mode, while improving the efficiency and reliability of the battery operated boost mode.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is the national phase entry of International Application No. PCT/CN2015/088721, filed on Sep. 1, 2015, which is based upon and claims priority to Chinese Application No. CN201510495221.5, filed on Aug. 13, 2015, the entire contents of which are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to the field of boost rectifier module and uninterrupted power supply, especially for a three-phase boost rectifier circuit with its control methods and uninterrupted power supply. 
       BACKGROUND OF THE INVENTION 
       [0003]    The traditional duce-phase uninterrupted power supply (UPS) generally uses three-phase half budge rectifier boost topology that comprising a single battery pact which can only control the sum of voltage of positive and negative bus. In order to maintain the balance of the positive and negative bus&#39;s voltage, current technology usually adds a balancing device, as shown in  FIG. 1 . With the technical proposal, the cost and circuit complexity are increased, meanwhile the reliability of the boost in battery state is decreased. At the same time, the balancing device generates additional power consumption while maintain the balance of the positive and negative bus&#39;s voltage, which reduces the efficiency of the boost under battery state. 
         [0004]    In addition, as shown in  FIG. 2 , the rectifier boost topology that use single battery pack with its negative pole connected with the negative pole of bus bar comprising the topology that applied to two level and three-level. However, in modular UPS, the multi module UPS needs to share the battery pack, and the positive and negative bus of each module UPS is independent. Therefore, the topology mentioned above cannot applied to modular UPS. 
         [0005]    The modular UPS has high flexibility of power expansion and has easy online maintenance, which is the mainstream of the future development direction of high frequency UPS and has been widely used in banking, communications and data centers and other fields. As shown in  FIG. 3 , modular UPS is generally use three-phase positive and negative double boost rectifier boost topology that comprising dual battery pack, which can realize that multiple module share one battery pack and the positive and negative bus between different modules is independent. However, the topology just mentioned increase three inductors and three thyristor compared with the rectifier boost topology that use single battery pack. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention aims to provide a three-phase boost rectifier circuit with its control methods and uninterrupted power supply, which can ensure the balance of positive and negative bus&#39;s voltage without the balancing device under battery operated boost mode, meanwhile improve the efficiency and reliability of the battery operated boost mode. 
         [0007]    To achieve the above purpose, the technology options of this invention are: a three-phase boost rectifier circuit, comprising first battery packs BAT+, second battery packs BAT−, and a boost rectifier module; the boost rectifier module comprising a first bidirectional thyristor SCR 1 , a second bidirectional thyristor SCR 2 , a third bidirectional thyristor SCR 3 , a fourth bidirectional thyristor SCR 6 , a first unidirectional thyristor SCR 4 , a second unidirectional thyristor SCR 5 , a first inductor L 1 , a second inductor L 2 , a third inductor L 3 , a three-phase fully controlled rectifier bridge, a first capacitor C 1 , a second capacitor C 2 ; one end of the first bidirectional thyristor SCR 1 , one end of the second bidirectional thyristor SCR 2  and one end of the third bidirectional thyristor SCR 3  are respectively connected to the first phase of three-phase power, the second phase of three-phase power and the third phase of three-phase power; the anode of the first unidirectional thyristor SCR 4  and the cathode of the second unidirectional thyristor SCR 5  are respectively connected to the positive end of the first battery packs BAT+ and the negative end of the second battery packs BAT−; the negative end of the first battery packs BAT+, the positive end of the second battery packs BAT− and one end of the fourth bidirectional thyristor SCR 6  are connected to the zero line of three-phase power; the cathode of the first unidirectional thyristor SCR 4  and the other end of the first bidirectional thyristor SCR 1  are both connected to the one end of the first inductor L 1 ; the other end of the second bidirectional thyristor SCR 2  and the other end of the fourth bidirectional thyristor SCR 6  are both connected to the one end of the second inductor L 2 ; the other end of the third bidirectional thyristor SCR 3  and the anode of the second unidirectional thyristor SCR 5  are both connected to the one end of the third inductor L 3 ; the other end of the first inductor L 1 , the other end of the second inductor L 2  and the other end of the third inductor L 3  are respectively connected to the three-phase inputs of the three-phase fully controlled rectifier bridge; the two outputs of the three-phase fully controlled rectifier bridge are respectively connected to one end of the first capacitor C 1  and one end of the second capacitor C 2 ; the other end of the first capacitor C 1  and the other end of the second capacitor C 2  are both connected to the zero line of three-phase power. 
         [0008]    Further, the three-phase fully controlled rectifier bridge is two-level power supplied three-phase bridge topology, which comprising a first switching device, a second switching device, a third switching device, a fourth switching device, a fifth switching device, a sixth switching device; the collector or drain of the first switching device, the collector or drain of the third switching device and the fifth switching device are connected as the first output of the three-phase fully controlled rectifier bridge; the transmitter or source of the second switching device, the fourth switching device and the sixth switching device are connected as the second output of the three-phase fully controlled rectifier bridge; the transmitter or source of the first switching device is connected with the collector or drain of the second switching device as the first phase input of the three-phase fully controlled rectifier bridge; the transmitter or source of the third switching device is connected with the collector or drain of the fourth switching device as the second phase input of the three-phase fully controlled rectifier bridge; the transmitter or source of the fifth switching device is connected with the collector or drain of the sixth switching device as the third phase input of the three-phase fully controlled rectifier bridge. 
         [0009]    Further, the three-phase fully controlled rectifier bridge is three-level power supplied three-phase half bridge topology which is I-type three-level inverting topology unit, or three-level power supplied three-phase half bridge topology which is T-type three-level inverting topology unit. 
         [0010]    Further, the three-level power supplied three-phase half bridge topology which is I-type three-level inverting topology unit comprising first switching device to twelfth switching device and first diode to sixth diode; the transmitter or source of the first switching device and the collector or drain of the second switching device are both connected to the cathode of the first diode; the transmitter or source of the fifth switching device and the collector or drain of the sixth switching device are both connected to the cathode of the third diode; the transmitter or source of the ninth switching device and the collector or drain of the tenth switching device are both connected to the cathode of the fifth diode; the transmitter or source of the third switching device and the collector or drain of the fourth switching device are both connected to the anode of the second diode; the transmitter or source of the seventh switching device and the collector or drain of the eighth switching device are both connected to the anode of the fourth diode; the transmitter or source of the eleventh switching device and the collector or drain of the twelfth switching device are both connected to the anode of the sixth diode; the anode of the first diode is connected with the cathode of the second diode; the anode of the third diode is connected with the cathode of the fourth diode; the anode of the fifth diode is connected with the cathode of the sixth diode; the collector or drain of the first switching device, the collector or drain of the fifth switching device and the collector or drain of the ninth switching device are connected as the first output of the three-phase fully controlled rectifier bridge; the transmitter or source of the fourth switching device, the transmitter or source of the eighth switching device and the transmitter or source of the twelfth switching device are connected as the second output of the three-phase fully controlled rectifier bridge; the transmitter or source of the second switching device and the collector or drain of the third switching device are connected as the first phase input of the three-phase fully controlled rectifier bridge; the transmitter or source of the sixth switching device and the collector or drain of the seventh switching device are connected as the second phase input of the three-phase fully controlled rectifier bridge; the transmitter or source of the tenth switching device and the collector or drain of the eleventh switching device are connected as the third phase input of the three-phase fully controlled rectifier bridge; the anode of the first diode, the anode of the second diode and the anode of the third diode are connected to the zero line of three-phase power. 
         [0011]    Further, the three-level power supplied three-phase half bridge topology which is T-type three-level inverting topology unit comprising first switching device to sixth switching device and first diode to sixth diode; the transmitter or source of the first switching device is connected with the transmitter or source of the second switching device, the transmitter or source of the third switching device is connected with the transmitter or source of the fourth switching device, the transmitter or source of the fifth switching device is connected with the transmitter or source of the sixth switching device; the cathode of the first diode, the cathode of the third diode and the cathode of the fifth diode are connected as the first output of the three-phase fully controlled rectifier bridge; the anode of the second diode, the anode of the fourth diode and the anode of the sixth diode are connected as the second output of the three-phase fully controlled rectifier bridge; the anode of the first diode, the cathode of the second diode and the collector or drain of the first switching device are connected as the first phase input of the three-phase fully controlled rectifier bridge; the anode of the third diode, the cathode of the fourth diode and the collector or drain of the third switching device are connected as the second phase input of the three-phase fully controlled rectifier bridge; the anode of the fifth diode, the cathode of the sixth diode and the collector or drain of the fifth switching device are connected as the third phase input of the three-phase fully controlled rectifier bridge; the collector or drain of the second switching device, the collector or drain of the fourth switching device and the collector or drain of the sixth switching device are connected to the zero line of three-phase power. 
         [0012]    Further, the first bidirectional thyristor SCR 1 , the second bidirectional thyristor SCR 2 , the third bidirectional thyristor, the first inductor L 1 , the second inductor L 2 , the third inductor L 3 , the first switching device, the second switching device, the third switching device, the fourth switching device, the fifth switching device, the sixth switching device, the first capacitor C 1  and the second capacitor C 2  forming a rectifier boost power stage circuit under commercial power supply mode; 
         [0013]    The first battery packs BAT+, the second battery packs BAT−, the first unidirectional thyristor SCR 4 , the second unidirectional thyristor SCR 5 , the first inductor L 1 , the third inductor L 3 , the first switching device, the second switching device, the fifth switching device, the sixth switching device, the first capacitor C 1  and the second capacitor C 2  framing a rectifier boost power stage circuit under battery-operated mode. 
         [0014]    The invention also provides a control method of the three-phase boost rectifier circuit which is recorded above: 
         [0015]    when the commercial power supply is normal, make the first bidirectional thyristor SCR 1 , the second bidirectional thyristor SCR 2  and the third bidirectional thyristor SCR 3  in closed-state; meanwhile, make the first unidirectional thyristor SCR 4 , the second unidirectional thyristor SCR 5 , the fourth bidirectional thyristor SCR 6  in open-state; at this time, the three-phase boost rectifier circuit works in the commercial power supply mode; 
         [0016]    when the commercial power supply is abnormal, make the first bidirectional thyristor SCR 1 , the second bidirectional thyristor SCR 2 , the third bidirectional thyristor SCR 3 , the first switching device and the sixth switching device in open-state; meanwhile, make the first unidirectional thyristor SCR 4  and the second unidirectional thyristor SCR 5  in closed-state; at this time, the three-phase boost rectifier circuit works in the battery-operated mode. 
         [0017]    Further, the commercial power supply mode comprising the following stages: 
         [0018]    when the first phase&#39;s voltage of three-phase power is in the positive half cycle, make the first switching device in open-state; in the first stage, make the second switching device in closed-state; the first phase&#39;s voltage of three-phase power charges the first inductor L 1  through a circuit consist of the first bidirectional thyristor SCR 1 , the first inductor L 1 , the second switching device and the second capacitor C 2 ; in the second stage, make the second switching device in open-state; the first inductive discharge and the discharge current of the first inductive charge the first capacitor C 1  through a circuit consist of the body diode of the first switching device, the first capacitor C 1 , the first bidirectional thyristor SCR 1  and the first inductor L 1 ; 
         [0019]    when the first phase&#39;s voltage of three-phase power is in the negative half cycle, make the second switching device in open-state; in the third stage, make the first switching device in closed-state; the first phase&#39;s voltage of three-phase power charges the first inductor L 1  through a circuit consist of the first bidirectional thyristor SCR 1 , the first inductor L 1 , the first switching device and the first capacitor C 1 ; in the fourth stage, make the first switching device in open-state; the first inductive discharge and the discharge current of the first inductor L 1  charge the second capacitor C 2  through a circuit consist of the body diode of the second switching device, the second capacitor C 2 , the first bidirectional thyristor SCR 1  and the first inductor L 1 ; 
         [0020]    when the second phase&#39;s voltage of three-phase power is in the positive half cycle, make the third switching device in open-state; in the first stage, make the fourth switching device in closed-state; the second phase&#39;s voltage of three-phase power charges the second inductor L 2  through a circuit consist of the second bidirectional thyristor SCR 2 , the second inductor L 2 , the fourth switching device and the second capacitor C 2 ; in the second stage, make the fourth switching device in open-state; the second inductive discharge and the discharge current of the second inductive charge the first capacitor C 1  through a circuit consist of the body diode of the third switching device, the first capacitor C 1 , the second bidirectional thyristor SCR 2  and the second inductor L 2 ; 
         [0021]    when the second phase&#39;s voltage of three-phase power is in the negative half cycle, make the fourth switching device in open-state; in the third stage, make the third switching device in closed-state; the second phase&#39;s voltage of three-phase power charges the second inductor L 2  through a circuit consist of the second bidirectional thyristor SCR 2 , the second inductor L 2 , the third switching device and the first capacitor C 1 ; in the fourth stage, make the third switching device in open-state; the second inductive discharge and the discharge current of the second inductor L 2  charge the second capacitor C 2  through a circuit consist of the body diode of the fourth switching device, the second capacitor C 2 , the second bidirectional thyristor SCR 2  and the second inductor L 2 ; 
         [0022]    when the third phase&#39;s voltage of three-phase power is in the positive half cycle, make the fifth switching device in open-state; in the first stage, make the sixth switching device in closed-state; the third phase&#39;s voltage of three-phase power charges the third inductor L 3  through a circuit consist of the third bidirectional thyristor SCR 3 , the third inductor L 3 , the sixth switching device and the second capacitor C 2 ; in the second stage, make the sixth switching device in open-state; the third inductive discharge and the discharge current of the third inductive charge the first capacitor C 1  through a circuit consist of the body diode of the fifth switching device, the first capacitor C 1 , the third bidirectional thyristor SCR 3  and the third inductor L 3 ; 
         [0023]    when the third phase&#39;s voltage of three-phase power is in the negative half cycle, make the sixth switching device in open-state; in the third stage, make the fifth switching device in closed-stare; the third phase&#39;s voltage of three-phase power charges the third inductor L 3  through a circuit consist of the third bidirectional thyristor SCR 3 , the second inductor L 2 , the fifth switching device and the first capacitor C 1 ; in the fourth stage, make the third switching device in open-state; the third inductive discharge and the discharge current of the third inductor L 3  charge the second capacitor C 2  through a circuit consist of the body diode of the sixth switching device, the second capacitor C 2 , the third bidirectional thyristor SCR 3  and the third inductor L 3 . 
         [0024]    Further, the battery-operated mode comprising the following stages: 
         [0025]    in the first stage, make the second switching device and the fifth switching device in closed-state; at this time, the first inductor L 1  charges through a circuit consist of the first battery packs BAT+, the first unidirectional thyristor SCR 4 , the first inductor L 1 , the second switching device and the second capacitor C 2 ; the third inductor L 3  charges through a circuit consist of the second battery packs BAT−, the first capacitor C 1 , the fifth switching device, the third inductor L 3  and the second unidirectional thyristor SCR 5 ; 
         [0026]    in the second stage, make the second switching device and the fifth switching device in open-state; at this time, the first inductor L 1  discharges and the discharge current of the first inductor L 1  charge the first capacitor C 1  through a circuit consist of the body diode of the first switching device, the first capacitor C 1 , the first battery packs BAT+, the first unidirectional thyristor SCR 4  and the first inductor L 1 ; the third inductor L 3  discharges and the discharge current of the third inductor L 3  charge the second capacitor C 2  through a circuit consist of the second unidirectional thyristor SCR 5 , the second battery packs BAT−, the second capacitor C 2 , the body diode of the sixth switching device and the third inductor L 3 . 
         [0027]    Further, when the three-phase boost rectifier circuit works in the battery-operated mode, make the balanced bridge circuit which consist of the fourth bidirectional thyristor SCR 6 , the second inductor L 2 , the third switching device and the fourth switching device work, in order to keep the residual capacity of the first battery packs BAT+ as same as the residual capacity of the second battery packs BAT−, as well as maintain the load balance of the positive and negative DC bus. 
         [0028]    Further, making the balanced bridge circuit which consist of the fourth bidirectional thyristor SCR 6 , the second inductor L 2  the third switching device and the fourth switching device work comprising the following steps: 
         [0029]    step one: make a real-time detection of the current value of the first battery packs BAT+, the current value of the second battery packs BAT−, the voltage value of the first battery packs BAT+ and the voltage value of the second battery packs BAT−; 
         [0030]    step two: calculating the residual capacity of the first battery packs BAT+, the residual capacity of the second battery packs BAT− as well as the ratio K of the residual capacity of the first battery packs BAT+ and the residual capacity of the second battery packs BAT−, where K         0; 
         [0031]    Step three: make the fourth bidirectional thyristor SCR 6 , the third switching device and the fourth switching device work according to the value of K. 
         [0032]    Further, the step three, in details: 
         [0033]    when 0         K&lt;1, make the fourth bidirectional thyristor SCR 6  in closed-state while the third switching device in open-state; in the first stage, make the fourth switching device in closed-state, meanwhile the second inductor L 2  charges through a circuit consist of the fourth switching device, the second capacitor C 2 , the fourth bidirectional thyristor SCR 6  and the second inductor L 2 ; in the second stage, make the fourth switching device in open-state, meanwhile the first capacitor C 1  charges through a circuit consist of the first capacitor C 1 , the fourth bidirectional thyristor SCR 6 , the second inductor L 2  and the body diode of the third switching device; 
         [0034]    when K=1, make the fourth bidirectional thyristor SCR 6 , the third switching device and the fourth switching device in open-state; 
         [0035]    when K&gt;1, make the fourth bidirectional thyristor SCR 6  in closed-state while the fourth switching device in open-state; in the first stage, make the third switching device in closed-state, meanwhile the second inductor L 2  charges through a circuit consist of the first capacitor C 1 , the third switching device, the second inductor L 2  and the forth bidirectional thyristor SCR 6 : in the second stage, make the third switching device in open-state, meanwhile the second capacitor C 2  charges through circuit consist of the body diode of the fourth switching device, the second inductor L 2 , the fourth bidirectional thyristor SCR 6  and the second capacitor C 2 . 
         [0036]    In particular, the invention also provides an uninterrupted power supply based on the three-phase boost rectifier circuit, comprising the three-phase boost rectifier circuit and a inverter module, the inputs of the inverter module are connected with the outputs of the three-phase boost rectifier circuit. 
         [0037]    Compared with existing technologies, the invention has the following advantages: 
         [0038]    1. The boost rectifier circuit that proposed by the invention can share the power devices such as inductor, switching device, etc. The invention achieves different functions in different conditions by sharing the devices of the topology, which realizes the reuse of power level device, reduces the number of devices, improves the power density of the circuit as well as reduces the cost of the circuit. 
         [0039]    2. The boost rectifier circuit that proposed by the invention use dual battery packs, which means that battery packs can be shared between different devices. The invention reduces the battery configuration as well as enlarge the scope of application. 
         [0040]    3. The boost rectifier circuit that proposed by the invention can realize the positive and negative bus&#39;s independent boosting, also can maintain the balance of the positive and negative bus&#39;s voltage without the extra balance device. The invention allows the positive and negative bus bar to carry unbalanced load, which improves the reliability of the battery mode as well as reduces the cost. 
         [0041]    4. The boost rectifier circuit that proposed by the invention works in half bridge mode under commercial power supply. The input voltage and current can be operated in four phase, the rectifier also has the ability to boost and feedback, which enlarges the scope of application of the equipment. 
         [0042]    5. The invention achieves balance function by adding a fourth bidirectional thyristor SCR 6 , sharing the second inductor L 2 , the third switching transistors Q 3  and the fourth switching transistors Q 4  of the rectifier boost topology. On the one hand, the invention can ensure the remaining capacity of the first battery packs BAT+ and the second battery packs BAT− are consistent. On the other hand, the invention can ensure the load balance on the positive and negative DC bus by controlling the balance bridge. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0043]      FIG. 1  shows the three-phase bridge type two-level rectifier boost topology that use single battery pack in the conventional technology. 
           [0044]      FIG. 2  shows the three-phase bridge rectifier boost topology in that use single battery pack in the conventional technology. 
           [0045]      FIG. 3  shows the three-phase positive and negative double boost rectifier boost topology that use dual battery pack in the conventional technology. 
           [0046]      FIG. 4  shows the three-phase boost rectifier circuit in this invention. 
           [0047]      FIG. 5  shows the two-level power supplied three-phase bridge topology that with dual battery packs in embodiment 1. 
           [0048]      FIG. 6  shows the sketch of the three-phase boost rectifier circuit that works in commercial power supply mode in embodiment 1. 
           [0049]      FIG. 7  shows the working principle diagram in which the first phase voltage is in positive half cycle and in the first stage of the rectifying and boosting. 
           [0050]      FIG. 8  shows the working principle diagram in which the first phase voltage is in positive half cycle and in the second stage of the rectifying and boosting. 
           [0051]      FIG. 9  shows the working principle diagram in which the first phase voltage is in negative half cycle and in the third stage of the rectifying and boosting. 
           [0052]      FIG. 10  shows the working principle diagram in which the first phase voltage is in negative half cycle and in the fourth stage of the rectifying and boosting. 
           [0053]      FIG. 11  shows the working principle diagram of the first stage of the rectifying and boosting by first battery packs BAT+ under battery-operated mode. 
           [0054]      FIG. 12  shows the working principle diagram of the first stage of the rectifying and boosting by first battery packs BAT− under battery-operated mode. 
           [0055]      FIG. 13  shows the working principle diagram of the second stage of the rectifying and boosting by first battery packs BAT+ under battery-operated mode. 
           [0056]      FIG. 14  shows the working principle diagram of the second stage of the rectifying and boosting by first battery packs BAT− under battery-operated mode. 
           [0057]      FIG. 15  shows the working principle diagram of the first stage of the balanced bridge when 0         K&lt;1. 
           [0058]      FIG. 16  shows the working principle diagram of the second stage of the balanced bridge when 0         K&lt;1. 
           [0059]      FIG. 17  shows the working principle diagram of the first stage of the balanced bridge when K&gt;1. 
           [0060]      FIG. 18  shows the working principle diagram of the second stage of the balanced bridge when K&gt;1. 
           [0061]      FIG. 19  shows the three-level power supplied three-phase half bridge topology which is I-type three-level inverting topology unit that with dual battery packs in embodiment 2. 
           [0062]      FIG. 20  shows the three-level power supplied three-phase half bridge topology which is T-type three-level inverting topology, unit that with dual battery packs in embodiment 3. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0063]    To allow the above features and advantages of this invention become more filly understood, especially cite the example below, and with the accompanying drawings, described in detail below, but the invention is not limited to this. 
       Embodiment 1 
       [0064]    As shown in  FIG. 4 , a three-phase boost rectifier circuit, comprising positive battery packs BAT+, second battery packs BAT−, and a boost rectifier module; the boost rectifier module comprising a first bidirectional thyristor SCR 1 , a second bidirectional thyristor SCR 2 , a third bidirectional thyristor SCR 3 , a fourth bidirectional thyristor SCR 6 , a first unidirectional thyristor SCR 4 , a second unidirectional thyristor SCR 5 , a first inductor L 1 , a second inductor L 2 , a third inductor L 3 , a three-phase fully controlled rectifier bridge, a first capacitor C 1 , a second capacitor C 2 ; one end of the first bidirectional thyristor SCR 1 , one end of the second bidirectional thyristor SCR 2  and one end of the third bidirectional thyristor SCR 3  are respectively connected to the first phase of three-phase power, the second phase of three-phase power and the third phase of three-phase power; the anode of the first unidirectional thyristor SCR 4  and the cathode of the second unidirectional thyristor SCR 5  are respectively connected to the positive end of the first battery packs BAT+ and the negative end of the second battery packs BAT−; the negative end of the first battery packs BAT+, the positive end of the second battery packs BAT− and one end of the fourth bidirectional thyristor SCR 6  are connected to the zero line of three-phase power; the cathode of the first unidirectional thyristor SCR 4  and the other end of the first bidirectional thyristor SCR 1  are both connected to the one end of the first inductor L 1 ; the other end of the second bidirectional thyristor SCR 2  and the other end of the fourth bidirectional thyristor SCR 6  are both connected to the one end of the second inductor L 2 ; the other end of the third bidirectional thyristor SCR 3  and the anode of the second unidirectional thyristor SCR 5  are both connected to the one end of the third inductor L 3 ; the other end of the first inductor L 1 , the other end of the second inductor L 2  and the other end of the third inductor L 3  are respectively connected to the three-phase inputs of the three-phase fully controlled rectifier bridge; the two outputs of the three-phase fully controlled rectifier bridge are respectively connected to one end of the first capacitor C 1  and one end of the second capacitor C 2 ; the other end of the first capacitor C 1  and the other end of the second capacitor C 2  are both connected to the zero line of three-phase power. 
         [0065]    In this embodiment, as shown in  FIG. 5 , the three-phase fully controlled rectifier bridge is two-level power supplied three-phase bridge topology, which comprising a first switching transistor Q 1  and its body diode D 1 , a second switching transistor Q 2  and its body diode D 2 , a third switching transistor Q 3  and its body diode D 3 , a fourth switching transistor Q 4  and its body diode D 4 , a fifth switching transistor Q 5  and its body diode D 5 , a sixth switching. transistor Q 6  and its body diode D 6 ; the collector of the first switching transistor Q 1 , the third switching transistor Q 3  and the fifth switching transistor Q 5  are connected as the first output of the three-phase fully controlled rectifier bridge; the transmitter of the second switching transistor Q 2 , the fourth switching transistor Q 4  and the sixth switching transistor Q 6  are connected as the second output of the three-phase fully controlled rectifier bridge; the transmitter of the first switching transistor Q 1  is connected with the collector of the second switching transistor Q 2  as the first phase input of the three-phase fully controlled rectifier bridge; the transmitter of the third switching transistor Q 3  is connected with the collector of the fourth switching transistor Q 4  as the second phase input of the three-phase fully controlled rectifier bridge; the transmitter of the fifth switching transistor Q 5  is connected with the collector of the sixth switching transistor Q 6  as the third phase input of the three-phase fully controlled rectifier bridge. 
         [0066]    In this embodiment, as shown in  FIG. 6 , the first bidirectional thyristor SCR 1 , the second bidirectional thyristor SCR 2 , the third bidirectional thyristor SCR 3  the first inductor L 1 , the second inductor L 2 , the third inductor L 3 , the first switching transistor Q 1 , the second switching transistor Q 2 , the third switching transistor Q 3 , the fourth switching transistor Q 4 , the fifth switching transistor Q 5 , the sixth switching transistor Q 6 , the first capacitor C 1  and the second capacitor C 2  forming a rectifier boost power stage circuit under commercial power supply mode; 
         [0067]    The first battery packs BAT+, the second battery packs BAT−, the first unidirectional thyristor SCR 4 , the second unidirectional thyristor SCR?, the first inductor L 1 , the third inductor L 3 , the first switching transistor Q 1 , the second switching transistor Q 2 , the fifth switching transistor Q 5 , the sixth switching transistor Q 6 , the first capacitor C 1  and the second capacitor C 2  forming a rectifier boost power stage circuit under battery-operated mode. 
         [0068]    This embodiment also provides a control method of the three-phase boost rectifier circuit which is recorded above: 
         [0069]    when the commercial power supply is normal, make the first bidirectional thyristor SCR 1 , the second bidirectional thyristor SCR 2  and the third bidirectional thyristor SCR 3  in closed-state; meanwhile, make the first unidirectional thyristor SCR 4 , the second unidirectional thyristor SCR 5 , the fourth bidirectional thyristor SCR in open-state; at this time, the three-phase boost rectifier circuit works in the commercial power supply mode; 
         [0070]    when the commercial power supply is abnormal, make the first bidirectional thyristor SCR, the second bidirectional thyristor SCR 2 , the third bidirectional thyristor SCR 3 , the first switching transistor Q 1  and the sixth switching transistor Q 6  in open-state; meanwhile, make the first unidirectional thyristor SCR 4  and the second unidirectional thyristor SCR 5  in closed-state; at this time, the three-phase boost rectifier circuit works in the battery-operated mode. 
         [0071]    In this embodiment, the commercial power supply mode comprising the following stages: 
         [0072]    when the first phase&#39;s voltage of three-phase power is in the positive half cycle, make the first switching transistor Q 1  in open-state; in the first stage, as shown in  FIG. 7 , make the second switching transistor Q 2  in closed-state; the first phase&#39;s voltage of three-phase power charges the first inductor L 1  through a circuit consist of the first bidirectional thyristor SCR 1 , the first inductor L 1 , the second switching transistor Q 2  and the second capacitor C 2 ; in the second stage, as shown in  FIG. 8 , make the second switching transistor Q 2  in open-state; the first inductive L 1  discharge and the discharge current of the first inductive L 1  charge the first capacitor C 1  through a circuit consist of the body diode of the first switching transistor Q 1 , the first capacitor C 1 , the first bidirectional thyristor SCR 1  and the first inductor L 1 ; 
         [0073]    when the first phase&#39;s voltage of three-phase power is in the negative half cycle, make the second switching transistor Q 2  in open-state; in the third stage, as shown in  FIG. 9 , make the first switching transistor Q 1  in closed-state; the first phase&#39;s voltage of three-phase power charges the first inductor L 1  through a circuit consist of the first bidirectional thyristor SCR 1 , the first inductor L 1 , the first switching transistor Q 1  and the first capacitor C 1 ; in the fourth stage, as shown in  FIG. 10 , make the first switching transistor Q 1  in open-state; the first inductive L 1  discharge and the discharge current of the first inductor L 1  charge the second capacitor C 2  through a circuit consist of the body diode of the second switching transistor Q 2 , the second capacitor C 2  the first bidirectional thyristor SCR 1  and the first inductor L 1 ; 
         [0074]    when the second phase&#39;s voltage of three-phase power is in the positive half cycle, make the third switching transistor Q 3  in open-state; in the first stage, make the fourth switching transistor Q 4  in closed-state; the second phase&#39;s voltage of three-phase power charges the second inductor L 2  through a circuit consist of the second bidirectional thyristor SCR 2 , the second inductor L 2 , the fourth switching transistor Q 4  and the second capacitor C 2 ; in the second stage, make the fourth switching transistor Q 4  in open-state; the second inductive L 2  discharge and the discharge current of the second inductive charge the first capacitor C I through a circuit consist of the body diode of the third switching transistor Q 3 , the first capacitor C 1 , the second bidirectional thyristor SCR 2  and the second inductor L 2 ; 
         [0075]    when the second phase&#39;s voltage of three-phase power is in the negative half cycle, make the fourth switching transistor Q 4  in open-state; in the third stage, make the third switching transistor Q 3  in closed-state; the second phase&#39;s voltage of three-phase power charges the second inductor L 2  through a circuit consist of the second bidirectional thyristor SCR 2 , the second inductor L 2 , the third switching transistor Q 3  and the first capacitor C 1 ; in the fourth stage, make the third switching transistor Q 3  in open-state; the second inductive L 2  discharge and the discharge current of the second inductor L 2  charge the second capacitor C 2  through a circuit consist of the body diode of the fourth switching transistor Q 4 , the second capacitor C 2 , the second bidirectional thyristor SCR 2  and the second inductor L 2 ; 
         [0076]    when the third phase&#39;s voltage of three-phase power is in the positive half cycle, make the fifth switching transistor Q 5  in open-state; in the first stage, make the sixth switching transistor Q 6  in closed-state; the third phase&#39;s voltage of three-phase power charges the third inductor L 3  through a circuit consist of the third bidirectional thyristor SCR 3 , the third inductor L 3 , the sixth switching transistor Q 6  and the second capacitor C 2 ; in the second stage, make the sixth switching. transistor Q 6  in open-state; the third inductive L 3  discharge and the discharge current of the third inductive charge the first capacitor C 1  through a circuit consist of the body diode of the fifth switching transistor Q 5 , the first capacitor C 1 , the third bidirectional thyristor SCR 3  and the third inductor L 3 ; 
         [0077]    when the third phase&#39;s voltage of three-phase power is in the negative half cycle, make the sixth switching transistor Q 6  in open-state; in the third stage, make the fifth switching transistor Q 5  in closed-state; the third phase&#39;s voltage of three-phase power charges the third inductor L 3  through a circuit consist of the third bidirectional thyristor SCR 3 , the second inductor L 2 , the fifth switching transistor Q 5  and the first capacitor C 1 ; in the fourth stage, make the third switching transistor Q 3  in open-state; the third inductive L 3  discharge and the discharge current of the third inductor L 3  charge the second capacitor C 2  through a circuit consist of the body diode of the sixth switching transistor Q 6 , the second capacitor C 2 , the third bidirectional thyristor SCR 3  and the third inductor L 3 . 
         [0078]    In this embodiment, the battery-operated mode comprising the following stages: 
         [0079]    In the first stage, make the second switching transistor Q 2  and the fifth switching transistor Q 5  in closed-state; as shown in  FIG. 11 , at this time, the first inductor L 1  charges through a circuit consist of the first battery packs BAT+, the first unidirectional thyristor SCR 4 , the first inductor L 1 , the second switching transistor Q 2  and the second capacitor C 2 ; as shown in  FIG. 12 , the third inductor L 3  charges through a circuit consist of the second battery packs BAT−, the first capacitor C 1 , the fifth switching transistor Q 5 , the third inductor L 3  and the second unidirectional thyristor SCR 5 ; 
         [0080]    In the second stage, make the second switching transistor Q 2  and the fifth switching transistor Q 5  in open-state; as shown in  FIG. 13 , at this time, the first inductor L 1  discharges and the discharge current of the first inductor L 1  charge the first capacitor C 1  through a circuit consist of the body diode of the first switching transistor Q 1 , the first capacitor C 1 , the first battery packs BAT+, the first unidirectional thyristor SCR 4  and the first inductor L 1 ; as shown in  FIG. 14 , the third inductor L 3  discharges and the discharge current of the third inductor L 3  charge the second capacitor C 2  through a circuit consist of the second unidirectional thyristor SCR 5 , the second battery packs BAT−, the second capacitor C 2 , the body diode of the sixth switching transistor Q 6  and the third inductor L 3 . 
         [0081]    Especially, when the three-phase boost rectifier circuit works in the battery-operated mode, make the balanced bridge circuit which consist of the fourth bidirectional thyristor SCR 6 , the second inductor L 2 , the third switching transistor Q 3  and the fourth switching transistor Q 4  work, in order to keep the residual capacity of the first battery packs BAT+ as same as the residual capacity of the second battery packs BAT−, as well as maintain the load balance of the positive and negative DC bus. 
         [0082]    Further, making the balanced bridge circuit which consist of the fourth bidirectional thyristor SCR 6 , the second inductor L 2 , the third switching transistor Q 3  and the fourth switching transistor Q 4  work comprising the following steps: 
         [0083]    Step one: make a real-time detection of the current value of the first battery packs BAT+, the current value of the second battery packs BAT−, the voltage value of the first battery packs UBAT+ and the voltage value of the second battery packs UBAT−; 
         [0084]    Step two: calculating the residual capacity of the first battery packs QBAT+, the residual capacity of the second battery packs QBAT− as well as the ratio K of the residual capacity of the first battery packs BAT+ and the residual capacity of the second battery packs BAT−, where K         0; 
         [0085]    Step three: make the fourth bidirectional thyristor SCR 6 , the third switching transistor Q 3  and the fourth switching transistor Q 4  work according to the value of K. 
         [0086]    In this embodiment, the step three, in details: 
         [0087]    when 0         K&lt;1, make the fourth bidirectional thyristor SCR 6  in closed-state while the third switching transistor Q 3  in open-state; as shown in  FIG. 15 , in the first stage, make the fourth switching transistor Q 4  in closed-state, meanwhile the second inductor L 2  charges through a circuit consist of the fourth switching transistor Q 4 , the second capacitor C 2 , the fourth bidirectional thyristor SCR and the second inductor L 2 ; in the second stage, as shown in  FIG. 16 , make the fourth switching transistor Q 4  in open-state, meanwhile the first capacitor C 1  charges through a circuit consist of the first capacitor C 1 , the fourth bidirectional thyristor SCR 6 , the second inductor L 2  and the body diode of the third switching transistor Q 3 ; 
         [0088]    when K=1, make the fourth bidirectional thyristor SCR 6 , the third switching transistor Q 3  and the fourth switching transistor Q 4  in open-state; 
         [0089]    when K&gt;1, make the fourth bidirectional thyristor SCR 6  in closed-state while the fourth switching transistor Q 4  in open-state; in the first stage, as shown in  FIG. 17 , make the third switching transistor Q 3  in closed-state, meanwhile the second inductor L 2  charges through a circuit consist of the first capacitor C 1 , the third switching transistor Q 3 , the second inductor L 2  and the fourth bidirectional thyristor SCR 6 ; in the second stage, as shown in  FIG. 18 , make the third switching transistor Q 3  in open-state, meanwhile the second capacitor C 2  charges through a circuit consist of the body diode of the fourth switching transistor Q 4 , the second inductor L 2 , the fourth bidirectional thyristor SCR 6  and the second capacitor C 2 . 
       Embodiment 2 
       [0090]    As shown in  FIG. 19 , this embodiment provide a three-phase boost rectifier circuit, comprising positive battery packs BAT+, second battery packs BAT−, and a boost rectifier module; the boost rectifier module comprising a first bidirectional thyristor SCR 1 , a second bidirectional thyristor SCR 2 , a third bidirectional thyristor SCR 3 , a fourth bidirectional thyristor SCR 6 , a first unidirectional thyristor SCR 4 , a second unidirectional thyristor SCR 5 , a first inductor L 1 , a second inductor L 2 , a third inductor L 3 , a three-phase fully controlled rectifier bridge, a first capacitor C 1 , a second capacitor C 2 ; one end of the first bidirectional thyristor SCR 1 , one end of the second bidirectional thyristor SCR 2  and one end of the third bidirectional thyristor SCR 3  are respectively connected to the first phase of three-phase power, the second phase of three-phase power and the third phase of three-phase power; the anode of the first unidirectional thyristor SCR 4  and the cathode of the second unidirectional thyristor SCR 5  are respectively connected to the positive end of the first battery packs BAT+ and the negative end of the second battery packs BAT−; the negative end of the first battery packs BAT+, the positive end of the second battery packs BAT− and one end of the fourth bidirectional thyristor SCR 6  are connected to the zero line of three-phase power; the cathode of the first unidirectional thyristor SCR 4  and the other end of the first bidirectional thyristor SCR 1  are both connected to the one end of the first inductor L 1 ; the other end of the second bidirectional thyristor SCR 2  and the other end of the fourth bidirectional thyristor SCR 6  are both connected to the one end of the second inductor L 2 ; the other end of the third bidirectional thyristor SCR 3  and the anode of the second unidirectional thyristor SCR 5  are both connected to the one end of the third inductor L 3 ; the other end of the first inductor L 1 , the other end of the second inductor L 2  and the other end of the third inductor L 3  are respectively connected to the three-phase inputs of the three-phase fully controlled rectifier bridge; the two outputs of the three-phase fully controlled rectifier bridge are respectively connected to one end of the first capacitor C 1  and one end of the second capacitor C 2 ; the other end of the first capacitor C 1  and the other end of the second capacitor C 2  are both connected to the zero line of three-phase power. 
         [0091]    In this embodiment the three-phase fully controlled rectifier bridge is three-level power supplied three-phase half bridge topology which is I-type three-level inverting topology unit. The three-level power supplied three-phase half bridge topology which is I-type three-level inverting topology unit comprising first switching device Q 1  to twelfth switching device Q 12  and first diode D 1  to sixth diode D 6 ; the transmitter or source of the first switching device Q 1  and the collector or drain of the second switching device Q 2  are both connected to the cathode of the first diode D 1 ; the transmitter or source of the fifth switching device Q 5  and the collector or drain of the sixth switching device Q 6  are both connected to the cathode of the third diode D 3 ; the transmitter or source of the ninth switching device Q 9  and the collector or drain of the tenth switching device Q 10  are both connected to the cathode of the fifth diode D 5 ; the transmitter or source of the third switching device Q 3  and the collector or drain of the fourth switching device Q 4  are both connected to the anode of the second diode D 2 ; the transmitter or source of the seventh switching device Q 7  and the collector or drain of the eighth switching device QS are both connected to the anode of the fourth diode D 4 ; the transmitter or source of the eleventh switching device Q 11  and the collector or drain of the twelfth switching device Q 12  are both connected to the anode of the sixth diode D 6 ; the anode of the first diode D 1  is connected with the cathode of the second diode D 2 ; the anode of the third diode D 3  is connected with the cathode of the fourth diode D 4 ; the anode of the fifth diode D 5  is connected with the cathode of the sixth diode D 6 ; the collector or drain of the first switching device Q 1 , the collector or drain of the fifth switching device Q 5  and the collector or drain of the ninth switching device Q 9  are connected as the first output of the three-phase fully controlled rectifier bridge; the transmitter or source of the fourth switching device Q 4 , the transmitter or source of the eighth switching device QS and the transmitter or source of the twelfth switching device Q 12  are connected as the second output of the three-phase fully controlled rectifier bridge; the transmitter or source of the second switching device Q 2  and the collector or drain of the third switching device Q 3  are connected as the first phase input of the three-phase fully controlled rectifier bridge; the transmitter or source of the sixth switching device Q 6  and the collector or drain of the seventh switching device Q 7  are connected as the second phase input of the three-phase fully controlled rectifier bridge; the transmitter or source of the tenth switching device Q 10  and the collector or drain of the eleventh switching device Q 11  are connected as the third phase input of the three-phase fully controlled rectifier bridge; the anode of the first diode, the anode of the second diode D 2  and the anode of the third diode D 3  are connected to the zero line of three-phase power. 
       Embodiment 3 
       [0092]    As shown in  FIG. 20 , this embodiment provide a three-phase boost rectifier circuit, comprising positive battery packs BAT+, second battery packs BAT−, and a boost rectifier module; the boost rectifier module comprising a first bidirectional thyristor SCR 1 , a second bidirectional thyristor SCR 2 , a third bidirectional thyristor SCR 3 , a fourth bidirectional thyristor SCR 6 , a first unidirectional thyristor SCR 4 , a second unidirectional thyristor SCR 5 , a first inductor L 1 , a second inductor L 2 , a third inductor L 3 , a three-phase fully controlled rectifier bridge, a first capacitor C 1 , a second capacitor C 2 ; one end of the first bidirectional thyristor SCR 1 , one end of the second bidirectional thyristor SCR 2  and one end of the third bidirectional thyristor SCR 3  are respectively connected to the first phase of three-phase power, the second phase of three-phase power and the third phase of three-phase power; the anode of the first unidirectional thyristor SCR 4  and the cathode of the second unidirectional thyristor SCR 5  are respectively connected to the positive end of the first battery packs BAT+ and the negative end of the second battery packs BAT−; the negative end of the first battery packs BAT+, the positive end of the second battery packs BAT− and one end of the fourth bidirectional thyristor SCR 6  are connected to the zero line of three-phase power; the cathode of the first unidirectional thyristor SCR 4  and the other end of the first bidirectional thyristor SCR 1  are both connected to the one end of the first inductor L 1 ; the other end of the second bidirectional thyristor SCR 2  and the other end of the fourth bidirectional thyristor SCR 6  are both connected to the one end of the second inductor L 2 ; the other end of the third bidirectional thyristor SCR 3  and the anode of the second unidirectional thyristor SCR 5  are both connected to the one end of the third inductor L 3 ; the other end of the first inductor L 1 , the other end of the second inductor L 2  and the other end of the third inductor L 3  are respectively connected to the three-phase inputs of the three-phase fully controlled rectifier bridge; the two outputs of the three-phase fully controlled rectifier bridge are respectively connected to one end of the first capacitor C 1  and one end of the second capacitor C 2 ; the other end of the first capacitor C 1  and the other end of the second capacitor C 2  are both connected to the zero line of three-phase power. 
         [0093]    In this embodiment, the three-phase fully controlled rectifier bridge is three-level power supplied three-phase half bridge topology which is T-type three-level inverting topology unit. The three-level power supplied three-phase half bridge topology which is T-type three-level inverting topology unit comprising first switching device to sixth switching device and first diode to sixth diode; the transmitter or source of the first switching device Q 1  is connected with the transmitter or source of the second switching device Q 2 , the transmitter or source of the third switching device Q 3  is connected with the transmitter or source of the fourth switching device Q 4 , the transmitter or source of the fifth switching device Q 5  is connected with the transmitter or source of the sixth switching device Q 6 ; the cathode of the first diode D 1 , the cathode of the third diode D 3  and the cathode of the fifth diode D 5  are connected as the first output of the three-phase fully controlled rectifier bridge; the anode of the second diode D 2 , the anode of the fourth diode D 4  and the anode of the sixth diode D 6  are connected as the second output of the three-phase fully controlled rectifier bridge; the anode of the first diode D 1 , the cathode of the second diode D 2  and the collector or drain of the first switching device Q 1  are connected as the first phase input of the three-phase fully controlled rectifier bridge; the anode of the third diode D 3 , the cathode of the fourth diode D 4  and the collector or drain of the third switching device Q 3  are connected as the second phase input of the three-phase fully controlled rectifier bridge; the anode of the fifth diode D 5 , the cathode of the sixth diode D 6  and the collector or drain of the fifth switching device Q 5  are connected as the third phase input of the three-phase fully controlled rectifier bridge; the collector or drain of the second switching device Q 2 , the collector or drain of the fourth switching device Q 4  and the collector or drain of the sixth switching device Q 6  are connected to the zero line of three-phase power.