Power electronic device, power electronic system and hot plug method for power unit

The disclosed is a power electronic device comprising a power unit and a mounting cubicle matching with the power unit. The mounting cubicle is provided with a rail and an entrance for pushing into and pulling out of the power unit. A side of the mounting cubicle is provided with an power source and control output terminal and a signal output terminal. A side of the power unit is provided with a power source and control input terminal and a signal input terminal. The power unit is provided with a micro-switch. When the power unit moves along the rail, after the power source and control input terminal contacts with the power source and control output terminal. The signal input terminal becomes electrically connected with the signal output terminal, and the micro-switch is turned on so as to start the power unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefits of Chinese Patent Application No. 201210364745.7, filed on Sep. 26, 2012 in the State Intellectual Property Office of China, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a power electronic device, a power electronic system and a hot plug method for a power unit.

BACKGROUND

In the conventional power electronic system, a number of IGBTs, inductors, capacitors, resistors and other components, as the major components of the power part, are installed to the cabinet separately, which means the entire power part is not modularized. Only in few power electronic systems there are a number of IGBTs or inductors, capacitors and resistors integrated into a power electronic device, namely the power part is modularized. Generally, one power electronic system includes a number of power electronic devices.

As shown inFIG. 1, in the conventional power electronic system, each power electronic device comprises a power unit1, a number of conductive terminals10and a number of connection terminals13. Power lines14connected to the power grid are connected to the conductive terminal10by screws20, and the conductive terminals10are connected to the power unit1, as a result, the power line14and the power unit1are electrically connected. The signal lines15are in electrical connection with the power unit1via the connection terminals13. The fixed connection of the power line14and the signal line15to the power unit1limits the moving range of the power unit1, as a result, there is no free plugging of the power electronic device with respect to the cabinet. If a power electronic device of the power electronic system occurs abnormal, the requirement of shutting down the entire power electronic system for maintenance or replacement would seriously affect the efficiency of the power electronic system.

Therefore, it cannot be achieved that the power electronic device is freely plugged with respect to the cabinet in the conventional power electronic system. Moreover, it cannot be achieved that the failed power electronic device is maintained or replaced in the case that other power electronic devices operate normally. In this case, it is needed to achieve an easy hot plug function.

SUMMARY

According to an aspect of the invention, a power electronic device is provided, comprising a power unit and a mounting cubicle matching with the power unit which has a rail and an entrance for pushing the power unit into the mounting cubicle and pulling the power unit out of the mounting cubicle. A side of the mounting cubicle away from the entrance is provided with an power source and control output terminal and a signal output terminal. A side of the power unit facing the power source and control output terminal and the signal output terminal is provided with a power source and control input terminal and a signal input terminal. The power unit is provided with a micro-switch. A distance between the signal output terminal and the signal input terminal is larger than a distance between the power source and control output terminal and the power source and control input terminal. When operating the power unit is required to be pushing into the mounting cubicle, the power unit moves along the rail, after the power source and control input terminal of the power unit contacts with the power source and control output terminal. As the power unit is pushed continuously. The signal input terminal of the power unit becomes electrically connected with the signal output terminal, and the micro-switch is turned on so as to start the power unit. When the operating power unit is required to be pulled out of the mounting cubicle, the micro-switch is turned off so as to stop the power unit, and the power unit moves toward the entrance along the rail, and the power unit is first disconnected with the signal output terminal and then the power unit is disconnected with the power source and control output terminal.

According to another aspect of the invention, a power electronic system comprising a cabinet and at least one power unit is provided. the cabinet comprises a plurality of mounting cubicles, wherein each of the mounting cubicles is provided with a rail and an entrance for pushing in and pulling out of the power unit. A side of the mounting cubicle away from the entrance is provided with an power source and control output terminal and a signal output terminal. A side of the power unit facing the power source and control output terminal and the signal output terminal is provided with a power source and control input terminal and a signal input terminal. The power unit is provided with a micro-switch. A distance between the signal output terminal and the signal input terminal is larger than a distance between the power source and control output terminal and the power source and control input terminal. When the power unit is required, the power unit is pushed into the mounting cubicle along the rail. After the power source and control input terminal of the power unit is first in electrical connection with the power source and control output terminal, as the power unit is pushed in continuously, the signal input terminal of the power unit becomes in electrically connected with the signal output terminal, after which the micro-switch is turned on and the power unit is turned on. When the power unit is required to be pulled out, the micro-switch is turned off and the power unit is turned off. The power unit moves toward the entrance along the rail, and the power unit is first disconnected with the signal output terminal and then the power unit is disconnected with the power source and control output terminal.

According to another aspect of the invention, a hot plug method for a power unit is provided, the method comprising steps of hot plugging a power unit into a mounting cubicle and/or hot plugging the power unit out of the mounting cubicle, wherein the mounting cubicle being provided with an power source and control output terminal and a signal output terminal, and the power unit being correspondingly provided with an power source and control input terminal and a signal input terminal, and a distance between the power source and control input terminal of the power unit and the power source and control output terminal of the mounting cubicle is less than a distance between the signal input terminal of the power unit and the signal output terminal of the mounting cubicle. The step of hot plugging the power unit into the mounting cubicle comprises pushing the power unit into the mounting cubicle; moving the power unit continuously such that the power source and control input terminal of the power unit becomes electrically connected with the power source and control output terminal of the mounting cubicle; further moving the power unit into the mounting cubicle such that the signal input terminal of the power unit becomes electrically connected with the signal output terminal of the mounting cubicle; operating a micro-switch provided on the power unit to turn on the power unit. The step of hot plugging the power unit out of the mounting cubicle comprises operating the micro-switch provided on the power unit to turn off the power unit; pulling out the power unit such that the signal input terminal of the power unit is electrically disconnected with the signal output terminal of the mounting cubicle; further pulling out the power unit such that the power source and control input terminal of the power unit is electrically disconnected with the power source and control output terminal of the mounting cubicle.

DETAILED DESCRIPTION

Several exemplary embodiments which reflect the characteristics and advantages of the present invention will be described in detail. The invention may, however, be embodied in many different forms without departing from the principles of the invention. Moreover, the following detailed description of the embodiments of the invention and the accompanying drawings are provided so that this disclosure will be thorough and complete, and should not be construed as limiting the present invention.

The above and other technical content, feature and effect of the present invention will be illustrated with reference to the detailed description of the following embodiments.

The technical idea is that, the power electronic device is used as the basis core to cooperate with the power and control output terminal and the signal output terminal fixed to the mounting cabinet, the power source and control input terminal and the signal input terminal fixed to the power unit, and the rail for the power unit to slide on. The sliding of the power unit along the rail achieves the connection or disconnection of the external current with or from the power unit, and thus the hot plug function of the power electronic device is realized.

Power Electronic Device

Referring toFIG. 2AthroughFIG. 7B, the shown power electronic device comprises a mounting cabinet100, a hot plug power unit1for the mounting cubicle100and a micro-switch5.

The shape of the mounting cubicle100matches that of the power unit1, which may be a cuboid, but is not limited thereto. An entrance130is provided on one side of the mounting cubicle100(defined as a front face in this embodiment) for plugging the power unit1into or out of the mounting cubicle100. A mounting beam7is fixed to the side away from the entrance130of the mounting cubicle100(defined as a rear side). A left rail110and a right rail120are located at two parallel edges of one side face (e.g., a side face perpendicular to the front face) of the cabinet100. The left rail110and the right rail120are applied to support the power unit1and to guide the power unit1to slide forward and backward in the mounting cubicle100, and thus the power unit1is plugged into or plugged out of the mounting cubicle100. Alternatively, the rails can be fixed on the bottom of the mounting cubicle100or other positions in the mounting cubicle100. The number of the rails is not limited to two, for example, it may be one or three and so on.

An power source and control output terminal and the signal output terminal are fixed on the mounting beam7of the mounting cubicle. The signal output terminal can be the sample current signal output terminal. For example, the power source and control output terminal are the power source and control plug2, which are electrically connected with a external power line and an external signal line. The power source and control output terminal may be divided into two plugs of a power source plug and a control plug. The power source plug is connected with the external power source line, and the control plug is connected with the external signal line. Therefore, the number of the plugs is selected according to the number of the practically makeable plugs, or is designed or selected according to the number of external signals practically required to be connected with the plugs, but not limited thereto.

The mounting beam7of the mounting cubicle100is provided with the signal output terminal, which for example may be a mechanically controlled contact45of a travel switch4. The travel switch4comprises a body41, a first terminal42and a second terminal43provided on the body41, and a mechanically controlled contact45with one end fixed to the body41. Wherein, the first terminal42and the second terminal43are electrically connected with signal lines respectively. The signal line for example may be a current signal line, or it may also be a voltage signal line. The signal line is a sample current signal line for example. When the travel switch4is in a non-working state, the first terminal42and the second terminal43are in a closed state (an electrically connected state), the sample current signal line, the first terminal42and the second terminal43form a loop, and the sample current signal does not pass through the power unit1. When the travel switch4is in a working state, for example, when the power unit1is in contact with the mechanically controlled contact45, the first terminal42and the second terminal43are in an open state, the sample current signal passes through the first terminal42, the mechanically controlled contact45and the power unit1. Thus, the sample current signal enters into the power unit1through the contact point of the mechanically controlled contact45.

The power unit may be a power quality compensator or a static var compensator (SVC). The shape of the power unit1may be a rectangle, for example, but not limited thereto. The rear side of the power unit1(namely the side facing the mounting beam7of the mounting cubicle100) is provided with a power source and control socket3corresponding to the electrical connection position of the power source and control output terminal. The power source and control socket3matches the power source and control plug2. The combination or separation of the power source and control socket3and the power source and control plug2can realize the electrical connection or the electrical disconnection between the power source and control socket3and the power source and control plug2, and between the power unit1and the external power line and the external signal line. In other embodiments, the power source and control plug may be divided into two plugs of a power source plug and a control plug. Accordingly, the power source and control socket are divided into a power source socket and a control socket matching the power source plug and control plug.

The rear side of the power unit1corresponding to the electrical connection position of the signal output terminal is further provided with a signal input terminal9matching with the signal output terminal, i.e., matching with the mechanically controlled contact45of the travel switch. That is, the contact or separation of the signal input terminal9and the mechanically controlled contact45controls the connection or disconnection between the first terminal42and the second terminal43of the travel switch4, and thus controls the electrical connection or electrical disconnection between the signal input terminal9of the power unit1and the external signal line. Due to varying type of the travel switches, the structure of the travel switch4is not limited to the example shown. Any other types of travel switch may be applied as long as the change of the relative distance between the power unit1and the travel switch can control on/off of the travel switch so as to control the connection or disconnection between the external signal and the power unit1.

Additionally, in the power electronic device according to other embodiments, the travel switch is not necessarily mounted on the rear side of the mounting cubicle100. Some travel switches of some existing structure may be mounted on the lateral side of the mounting cubicle100, and the matched signal input terminal is correspondingly provided on the lateral side of the power unit1.

In the case that the mounting cubicle100is not provided with the mounting beam7, the power source and control plug2, the travel switch4can be mounted on other position at the rear side of the mounting cubicle100, as long as they can contact and make electrically connected with the power source and control socket3, the signal input terminal9on the rear side of the power unit1.

Before forming the electrical connection between the power unit1and the external power source line, control line and signal line, the distance for electrical connection between the power source and control socket3and the power source and control plug2is less than the distance for electrical connection between the signal input terminal9and the signal output terminal, wherever the socket and plug are disposed. Referring toFIG. 2B, the signal output terminal is the mechanically controlled contact45of the travel switch4, the distance to achieve the electrical connection between the power source and control socket3and the power source and control plug2is the distance L1between the power contact21and the power source socket3. The distance to achieve the electrical connection between the signal input terminal9and the mechanically controlled contact45of the travel switch4is the distance L2between the signal input terminal9and the contact45of the travel switch4. As shown inFIG. 2B, the distance L1is less than the distance L2. This design is to ensure to form the electrical connection between the power source and control socket3and the power source and control plug2earlier than between the signal input terminal9and the travel switch4, during electrically connecting. At the same time, the electrical connection between the signal input terminal9and the travel switch4is formed earlier than that between the power source and control socket3and the power source and control plug2, during electrically disconnecting.

In the illustrated power electronic device, the micro-switch5is mounted on the power unit1to turn off or turn on the power unit1. In the micro-switch5of one embodiment, the micro-switch5comprises a micro-switch body51, an output terminal52and a micro-motion elastic piece54provided on the micro-switch body51. The output terminal52is electrically connected with the power unit1, and the electrical off/on signal of the micro-switch pass through the output terminal52to the power unit1. The compressed or released state of the micro-motion elastic piece54is corresponding to the on/off state of the micro-switch5respectively. It is to be noted that, in the exemplified micro-switch5according to the illustrated embodiment, “on” corresponds to the state of the micro-switch when the power unit is started, and “off” corresponds to the state of the micro-switch when the power unit is stopped. However, in other embodiments, the “on” and “off” states of the micro-switch5correspond to the stop and start of the power unit, respectively. The structure of the micro-switch is not limited to the illustrated embodiments; any other micro-switches which can start/stop the power unit1are applicable.

The power electronic device further comprises a control lock6. When the micro-switch5starts the power unit1to work, the control lock6fixes the position of the power unit1relative to the mounting cubicle100, to prevent the power unit1from being plugged out by mistake or to prevent other accidents from happening. The illustrated control lock6not only has a locking function, but also can control on/off of the micro-switch5. The power unit1further comprises a left-side plate11, a right-side plate12and a panel13. The left-side plate11and the right-side plate12extend forward from the left side and the right side of the power unit1. The panel is fixed to the front ends of the left-side plate11and the right-side plate12. The panel13is provided with a sliding groove131extending along the left-right direction (perpendicular to the rail). If the power unit1is not provided with the panel13, the sliding groove131may also be provided on the face of the power unit1exposed by the entrance when the power unit1is plugged into the mounting cubicle100.

Referring toFIG. 8A, the specific structure of a control lock6is illustrated as an example. The control lock6comprises a mechanical lock body and a mechanical sliding key60connecting to the mechanical lock body. The L-shaped mechanical lock body comprises a first body61and a second body62perpendicular to each other. The mechanical sliding key60is fixed to the first body61. With reference toFIGS. 6 through 7B, the first body61is bonded to the inside of the panel13. Corresponding to the mechanical sliding key, the panel13is provided with a sliding groove131for the mechanical sliding key60to slide in to drive the mechanical lock body. A lock tongue63protrudes from one side of the second body62. Referring toFIG. 6, for matching the lock tongue63, a first keyhole121is formed in the right side of the mounting cubicle100, a second keyhole122is formed in the right-side plate12of the power unit1. When the power unit1is plugged into place, the first keyhole121aligns with the second keyhole122, the mechanical sliding key60moves along the sliding groove131and can drive the lock tongue63to insert into or withdraw from the first keyhole121defined on the mounting cubicle100. Referring to5B, the micro-switch5is provided in the power unit1close to the mechanical sliding key60to achieve the control of the micro-switch5at the time of the control lock6locking or unlocking the mounting cubicle100and power unit1. When one end of the mechanical sliding key60slides under control, the other end of the mechanical sliding key60presses or releases the micro-motion elastic piece54of the micro-switch5to control the on/off of the micro-switch. In order to facilitate the motion of the mechanical sliding key60, a holding part64can be provided at the outer end of the mechanical sliding key60extending beyond the sliding groove131. Above mentioned is that the control lock6controls to turn on the micro-switch5and lock the power unit1simultaneously, or the control lock6controls to turn off the micro-switch and unlock the power unit1simultaneously. In some other embodiments, the locking or unlocking of the control lock6may be independent to the on/off of the micro-switch5.

In the power electronic device mentioned herewith, two parallel handles8are mounted on the panel13of the power unit1to facilitate the power unit1to be pushed in or pulled out of the mounting cubicle100. In order to save effort or realize automation, a designed or existing drive device can also be used to move the power unit1.

Power Electronic System

The power electronic system introduced herewith comprises a cabinet and at least two power units. The cabinet comprises a plurality of mounting cubicles. The mounting cubicles are arranged in arrays, e.g., 1×N arrangement, M×N arrangement (wherein M and N are natural numbers) or concentric arrangement. The mounting cubicle can be designed according to the actual formation of the cabinet. The number of the mounting cubicle may be equal to or more than that of the power electronic device.

The mounting cubicle is provided with a rail and an entrance for the power unit to be pushed in and pulled out. The side of the mounting cubicle away from the entrance is provided with an power source and control output terminal and the signal output terminal. The side of the power unit facing the power source and control output terminal and signal output terminal is provided with an power source and control input terminal and a signal input terminal. The power unit is also provided with a micro-switch. The distance between the signal output terminal and signal input terminal is larger than that between the power source and control output terminal and the power source and control input terminal. When the power unit is required, the power unit is mounted to the mounting cubicle along the rails. After the electrical connection between the power source and control input terminal and the power source and control output terminal is formed first, as the power unit continues being plugged into the mounting cubicle, the signal input terminal is in connection with the signal output terminal to turn on the micro-switch and start the power unit. When the power unit in operation is required to be unplugged, firstly the micro-switch is turned off and the power unit is turned off, and the power unit moves toward the entrance along the rail. The power unit first disconnects with the signal output terminal, and then the power unit disconnects with the power source and control output terminal. Therefore, each mounting cubicle of the cabinet may be provided with a power unit. The other parts of the mounting cubicle and the power unit that can be plugged in and unplugged out of the mounting cubicle in the power electronic system is the same as that described above and the description thereof is thus omitted.

In the power electronic system described herein, each power unit is independent and dose not interfere with each other, replacement or maintenance of one power unit in power off time dose not affect the normal operation of the other power unit. Therefore, in the case that the entire power electronic system is uninterrupted, the failed power unit is hot unplugged, the repaired power unit is hot plugged, or a target power unit is selectively unplugged or plugged, thereby greatly improving the operation efficiency of the power electronic system.

Hot Plug Method for the Power Unit

According to an exemplary embodiment, the hot plug method for the power unit comprises at least one step of hot plugging the power unit into a mounting cubicle and hot-plugging the power unit out of the mounting cubicle. The mounting cubicle is provided with the power source and control output terminal and signal output terminal, and the power unit is correspondingly provided with the power source and control input terminal and signal input terminal. The distance between the power source and control input terminal of the power unit and the power source and control output terminal of the mounting cubicle is less than that between the signal input terminal of the power unit and the signal output terminal of the mounting cubicle. The hot plug-into step comprises the sequential sub-steps of: plugging the power unit into the mounting cubicle to form the electrical connection between the power source and control input terminal of the power unit and the power source and control output terminal of the mounting cubicle, and then to form the electrical connection between the signal input terminal of the power unit and the signal output terminal of the mounting cubicle; turning on a micro-switch provided on the power unit to turn on the power unit. The hot plug-out step in reverse order of the hot plug-into step sequentially comprises: turning off the micro-switch provided on the power unit to turn off the power unit; plugging the signal input terminal of the power unit out of the signal output terminal of the mounting cubicle, and then plugging the power source and control input terminal of the power unit out of the power source and control output terminal of the mounting cubicle to disconnect the electrical connection. The method will be described in detail in combination of the power electronic device or the power electronic system explained above.

The hot plug-into step comprises the following sub-steps.

First of all, referring toFIGS. 2B and 3, the power unit1is pushed into the mounting cubicle100by holding the handles8, the power unit1is moved toward the power source and control plug2through the entrance of the mounting cubicle100, until the electrical connection between the power source and control socket3and the power source and control plug2is formed, thereby forming the electrical connection between the power unit1and the external power line, and the micro-switch is in OFF-state. When the power source and control plug2moves toward the power source and control socket3, the pin of the power source and control plug2is in contact with the power source and control socket3or with the slot provided in the power source and control socket3, the electrical connection between the power source and control plug and the external power line, signal line is formed, and thereby the electrical connection between the power unit1and the external power line, control line and/or signal line is formed.

Thereafter, referring toFIG. 4A, the power unit1is pushed along the original direction continuously, until the mechanical control contact45of the travel switch4is in contact with the signal input terminal9of the power unit1, thereby form the electrical connection between the external signal line and the power unit1. The travel switch4comprises a travel switch body41, a first terminal42, a second terminal43and a mechanical control contact45. When the power unit1moves to contact with the mechanical control contact45, the external signal flows through the first terminal42, the power unit1and the second terminal43, i.e., the power unit1is in electrical communication with the external signal.

Finally, referring to5A, the micro-switch of the power unit is turned on to turn the power unit1into the normal operation state.

The hot plug-out step comprises the following sub-steps.

First of all, referring toFIGS. 4A and 5A, when the power unit1is ready to be plugged out of the mounting cubicle100, the micro-switch is turned off to turn off the power unit1.

Thereafter, referring toFIG. 3, the power unit1is plugged outward (far away from the power source and control plug) through the entrance of the mounting cubicle100, the mechanical control contact45of the travel switch4moves away from the signal input terminal9of the power unit1, thereby disconnecting the external signal line with the power unit1.

Finally, referring toFIG. 2B, the power unit1further moves away from the power source and control plug2until the power source and control socket3disconnects with the power source and control plug2, and thus the power source and control socket3disconnects with the power source and control plug2.

During the hot plug-into or the hot plug-out step, the micro-switch is turned on/off under the control of the control lock. In one embodiment, the control lock6comprises the mechanical lock body and the mechanical sliding key60connecting therewith. The mechanical sliding key60moves along the left-right direction and contacts with or separates from the micro-motion elastic piece54of the micro-switch5to press or release the micro-motion elastic piece54, thereby turning on/off the micro-switch5under control. To ensure the moving direction of the mechanical sliding key60without offset, a sliding groove131may be defined on the panel13of the mounting cubicle100, the outer end of the mechanical sliding key60extends out of the sliding groove131to guide the sliding. In addition, the holding part64may be provided at the outer end of the mechanical sliding key60to facilitate holding. The lock tongue63projects from one side of the mechanical lock body. At this time, the first keyhole121is provided in the mounting cubicle100, e.g., in the right-side plate12of the mounting cubicle100. The control lock6turns on the micro-switch5and locks the power unit1to the mounting cubicle100to prevent the power unit1in the live operation from accidentally departing from the mounting cubicle100. The specific operation process is as follow: the holding part64moves rightward along the sliding groove131, and thus the mechanical sliding key60moves rightward. When the inner part of the mechanical sliding key60presses the micro-motion elastic piece54of the micro-switch5to turn on the micro-switch5, the electrical signal of the closed micro-switch5is transmitted to the power unit1through the output terminal52, and the turned-on power unit is in the operation state. At the same time, the lock tongue63provided on the second body62moves rightward accordingly; when the holding part64moves rightward until the micro-switch5is turned on (the power unit1turns on), the lock tongue63inserts into the first keyhole121through the second keyhole122, thereby locking the power unit1to the mounting cubicle100and preventing the power unit in operation state from dropping from the mounting cubicle100. Conversely, the holding part64is pushed leftward along the sliding groove131until the micro-switch is turned off, and the power unit1is unlocked from the mounting cubicle100accordingly.

One or more of exemplary embodiments of the invention provide at least one or more of the following advantageous effects.

The mounting cubicle is provided with the rail and the entrance. The mounting cubicle is provided with the power source and control output terminal in electrical connection with an external power line and the signal output terminal in electrical connection with an external signal line, and the power unit is provided with the power source and control input terminal and the signal input terminal matching the power source and control output terminal and the signal output terminal. Thereby, in the power electronic device of the present disclosure, the power unit can be inserted into and withdrawn from the mounting cubicle along the rail without the limitation of the external power line or the signal line. When the power unit is plugged into the mounting cubicle, the power source and control input terminal is in electrical connection with the power source and control output terminal, the signal input terminal is in electrical connection with the signal output terminal, thereby achieving the electrical connection between the power unit and the external power line and between the power unit and the external signal line. When the power unit is plugged out of the mounting cubicle, the power unit electrically is disconnected with the external power line and the external signal line. By the aid of the micro-switch of the power unit, the present power electronic in the live state can be turned on or turned off. Therefore, the hot plug function with respect to the mounting cubicle can be realized by the present power electronic device, resulting in easy assembling, disassembling and maintenance, safety operation, and convenience.

The present power electronic system comprises the cabinet having a plurality of mounting cubicles and a plurality of power units, and each mounting cubicle is provided with a power unit. When it is required for maintenance or change a failure power electronic device, the power electronic device can be directly pulled out of the mounting cubicle after being turned off by switching off the micro-switch of the power unit, without turning off the entire power system and affecting normal operation of the other power units. Meanwhile, the repaired power unit can be hot plugged into the power system in live state, thereby greatly improving the operation efficiency of the present power system.

The hot plug method for the present power unit comprises the step of hot plugging a power unit into the mounting cubicle and the step of hot plugging a power unit out of the mounting cubicle. The hot plugging of the power unit into the mounting cubicle comprises the following sub-steps: forming the electrical connection between the power source and control output terminal of the mounting cubicle and the power source and control input terminal of the power unit and subsequent electrical connection between the signal output terminal of the mounting cubicle and the signal input terminal of the power unit, and closing the micro-switch. The hot plugging of the power unit out of the mounting cubicle is reverse in sequent to the hot plugging of the power unit into the mounting cubicle, and the hot plugging of the power unit out of the mounting cubicle comprises the following sub-steps: switching off the micro-switch, the signal output terminal and the signal input terminal being electrically disconnected, and the power source and control output terminal and the power source and control input terminal being electrically disconnected. As such, the power electronic system can be reliably hot plugged, and the negative effect on the entire power system and other power electronic devices can be avoided.

And it should be noted that the above embodiments is only illustrated for describing the technical solution of the invention and not restrictive, and although the invention is described in detail by referring to the aforesaid embodiments, the skilled in the art should understand that the aforesaid embodiments can be modified and portions of the technical features therein may be equally changed, which does not depart from the spirit and scope of the technical solution of the embodiments of the invention.