Patent Publication Number: US-2023163627-A1

Title: Backup power supply system and control method thereof

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
     This application claims the benefit of priority to Taiwan Patent Application No. 110143316, filed on Nov. 22, 2021. The entire content of the above identified application is incorporated herein by reference. 
     Some references, which may include patents, patent applications and various publications, may be cited and discussed in the description of this disclosure. The citation and/or discussion of such references is provided merely to clarify the description of the present disclosure and is not an admission that any such reference is “prior art” to the disclosure described herein. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference. 
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to a backup power supply system and a control method thereof, and more particularly to a backup power supply system that can directly supply power to an alternating current load whether or not utility power is normal and a control method thereof. 
     BACKGROUND OF THE DISCLOSURE 
     An uninterruptible power supply (UPS) is an apparatus that has been widely used for managing problems associated with sudden abnormalities in utility power (e.g., a temporary power failure or a power interference). The uninterruptible power supply provides reliable backup power for a computer, a server, or a medical device, so that operation of these electronic devices will not be interrupted due to abnormal utility power conditions. 
     However, the conventional uninterruptible power supply can only provide a direct current (DC) voltage to a DC load. For certain alternating current (AC) loads (e.g., a display screen), the AC load cannot continue to operate normally in situations where the utility power is abnormal. 
     SUMMARY OF THE DISCLOSURE 
     In response to the above-referenced technical inadequacies, the present disclosure provides a backup power supply system and a control method thereof. 
     In one aspect, the present disclosure provides a backup power supply system. The backup power supply system includes power supply circuit and an uninterruptible power supply. The power supply circuit is configured to receive utility power, and the uninterruptible power supply is connected to the power supply circuit and stores backup power. The uninterruptible power supply includes an alternating current output terminal, and the alternating current output terminal is configured to connect to an alternating current load. When the utility power is normal, the power supply circuit supplies the power to the uninterruptible power supply, the alternating current output terminal of the uninterruptible power supply outputs a first alternating current voltage to the alternating current load. The first alternating current voltage meets a utility power specification. When the utility power is abnormal, the uninterruptible power supply supplies the power to the power supply circuit, the alternating current output terminal of the uninterruptible power supply outputs a second alternating current voltage to the alternating current load. The second alternating current voltage meets the utility power specification. 
     In another aspect, the present disclosure provides a control method of a backup power supply system. The backup power supply system comprises a power supply circuit and an uninterrupted power circuit, and the uninterrupted power circuit stores backup power. The control method comprises: determining, by the power supply circuit, whether utility power is normal; providing, by the power supply circuit, power to the uninterrupted power circuit when the utility power is normal; outputting, by the uninterrupted power circuit, a first alternating current voltage to an alternating current load when the utility power is normal, in which the first alternating current voltage meets a utility power specification; and outputting, by the uninterrupted power circuit, a second alternating current voltage to the alternating current load when the utility power is abnormal, in which the second alternating current voltage meets the utility power specification. 
     Therefore, in the backup power supply system and the control method thereof provided by the present disclosure, the backup power supply system can directly supply alternating current that meets the utility power specification to the alternating current (AC) load regardless of whether or not the utility power is normal. In this way, the AC load can continue to operate normally. 
     These and other aspects of the present disclosure will become apparent from the following description of the embodiment taken in conjunction with the following drawings and their captions, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The described embodiments may be better understood by reference to the following description and the accompanying drawings, in which: 
         FIG.  1    is a functional block diagram of a backup power supply system according to a first embodiment of the present disclosure; 
         FIG.  2    is flowchart of a control method of the backup power supply system in  FIG.  1   ; 
         FIG.  3    is a functional block diagram of a backup power supply system according to a second embodiment of the present disclosure; 
         FIG.  4    is flowchart of a control method of the backup power supply system in  FIG.  3   ; 
         FIG.  5    is a flowchart of a control method of a backup power supply system according to a third embodiment of the present disclosure; and 
         FIG.  6    is a functional block diagram of a backup power supply system according to a fourth embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     The present disclosure is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Like numbers in the drawings indicate like components throughout the views. As used in the description herein and throughout the claims that follow, unless the context clearly dictates otherwise, the meaning of “a”, “an”, and “the” includes plural reference, and the meaning of “in” includes “in” and “on”. Titles or subtitles can be used herein for the convenience of a reader, which shall have no influence on the scope of the present disclosure. 
     The terms used herein generally have their ordinary meanings in the art. In the case of conflict, the present document, including any definitions given herein, will prevail. The same thing can be expressed in more than one way. Alternative language and synonyms can be used for any term(s) discussed herein, and no special significance is to be placed upon whether a term is elaborated or discussed herein. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms is illustrative only, and in no way limits the scope and meaning of the present disclosure or of any exemplified term. Likewise, the present disclosure is not limited to various embodiments given herein. Numbering terms such as “first”, “second” or “third” can be used to describe various components, signals or the like, which are for distinguishing one component/signal from another one only, and are not intended to, nor should be construed to impose any substantive limitations on the components, signals or the like. 
       FIG.  1    is a functional block diagram of a backup power supply system according to a first embodiment of the present disclosure. Referring to  FIG.  1   , a backup power supply system A 1  comprises a power supply circuit  1  and an uninterruptible power supply  2 . The power supply circuit  1  includes a noise filter  101 , a full-wave rectifier circuit  103 , a power factor correction circuit  105 , a switch circuit  107 , a control circuit  109 , a transformer  111 , a filter circuit  113  and an output monitoring circuit  115 . The uninterruptible power supply  2  is connected to the output monitoring circuit  115 . 
     The purpose of the noise filter  101  is to reduce an electromagnetic interference (EMI). The noise filter  101  is provided with a utility power receiving terminal  1011 , and the utility power receiving terminal  1011  is configured to receive a utility power (Vac). 
     The full-wave rectifier circuit  103  is connected to an output terminal of the noise filter  101 , and the full-wave rectifier circuit  103  performs a full-wave rectification on the utility power (Vac), so as to convert negative voltages of the utility power (Vac) into positive voltages. 
     The power factor correction circuit  105  can be, for example, an active power factor correction circuit or a passive power factor correction circuit, and is connected to an output terminal of the full-wave rectifier circuit  103 . The function of the power factor correction circuit  105  is to increase a power factor of an alternating current (AC) voltage signal. 
     The switch circuit  107  can be, for example, a transistor switch circuit connected to an output terminal of the power factor correction circuit  105 . The function of the switch circuit  107  is to adjust a waveform of the AC voltage signal. The control circuit  109  is connected to the output monitoring circuit  115 , the power factor correction circuit  105 , and the switch circuit  107 . 
     The transformer  111  is connected to an output terminal of the switch circuit  107 , and an output voltage of the transformer  111  is lower than an input voltage of the transformer  111 . The filter circuit  113  is connected to the transformer  111  for eliminating ripples of the AC voltage signal. 
     The output monitoring circuit  115  is connected to an output terminal of the filter circuit  113  and an input terminal of the control circuit  109 . When the utility power is abnormal, the output monitoring circuit  115  cannot receive a voltage signal from the filter circuit  113 . At this time, the output monitoring circuit  115  outputs a first control instruction to the control circuit  109 . The control circuit  109  adjusts the power factor correction circuit  105  and the switch circuit  107  according to the first control instruction. Conversely, when the utility power is normal, the output monitoring circuit  115  receives the voltage signal from the filter circuit  113 . At this time, the output monitoring circuit  115  outputs a second control instruction to the control circuit  109 . The control circuit  109  adjusts the power factor correction circuit  105  and the switch circuit  107  according to the second control instruction. 
     The output monitoring circuit  115  includes a plurality of direct current (DC) load connection ports  1151 A to  1151 D, and the DC load connection ports  1151 A to  1151 D are configured to connect a plurality of different DC loads (DCL 1  to DCL 4 ). For example, the DC load connection ports  1151 A to  1151 D can output DC voltages with 12 volt, 5 volt, 5 volt, and 3.3 volt, respectively. 
     The uninterruptible power supply  2  includes a battery  21 , a battery management circuit  23 , and an inverter  25 . The battery  21  is connected to the output monitoring circuit  115 , the battery management circuit  23 , and the inverter  25 . The inverter  25  is provided with an alternating current (AC) output terminal  251 . The AC output terminal  251  of the inverter  25  is configured to connect an alternating current load (ACL). 
     When the utility power (Vac) is normal, the output monitoring circuit  115  provides the multiple DC voltages to the DC loads (DCL 1  to DCL 4 ) through the DC load connection ports  1151 A to  1151 D based on the utility power (Vac). A DC output terminal  1153  of the output monitoring circuit  115  outputs the DC voltage to the battery management circuit  23  of the uninterruptible power supply  2 . After the battery management circuit  23  receives the power from the output monitoring circuit  115 , the battery management circuit  23  supplies the power to the battery  21 , so that the battery  21  can store backup power. The battery  21  outputs the DC voltage to the inverter  25 , and the AC output terminal  251  of the inverter  25  outputs a first AC voltage that meets a utility power specification to the AC load (ACL). 
     When the utility power (Vac) is abnormal, one part of the backup power stored in the battery  21  is supplied to the output monitoring circuit  115  of the power supply circuit  1 , and another part of the backup power stored in the battery  21  is supplied to the inverter  25  of the uninterruptible power supply  2 . The output monitoring circuit  115  is provided with a plurality of different DC-DC converters. After the output monitoring circuit  115  receives the power from the battery  21 , the output monitoring circuit  115  converts the power from the battery  21  into the DC voltages with different volts and outputs these DC voltages with different volts to the DC loads DCL 1  to DCL 4  respectively through the DC load connection ports  1151 A to  1151 D. After the inverter  25  receives the power from the battery  21 , the AC output terminal  251  of the inverter  25  outputs a second AC voltage that meets the utility power specification to the AC load (ACL). 
       FIG.  2    is flowchart of a control method of the backup power supply system in  FIG.  1   . Referring to  FIG.  2   , in a step S 201 , the power supply circuit  1  determines whether or not the utility power is normal. When the utility power is normal, the step S 201  is followed by a step S 203 . In the step S 203 , the output monitoring circuit  115  respectively outputs the multiple DC voltages to the multiple DC loads (DCL 1  to DCL 4 ). The step S 203  is followed by a step S 205 . In the step S 205 , the output monitoring circuit  115  outputs the DC voltage to the battery management circuit  23  of the uninterruptible power supply  2 . The step S 205  is followed by a step S 207 . In the step S 207 , the battery management circuit  23  charges the battery  21  of the uninterruptible power supply  2 . The step S 207  is followed by a step S 209 . In the step S 209 , the battery  21  outputs the DC voltage to the inverter  25 . The step S 209  is followed by a step S 211 . In the step S 211 , the AC output terminal  251  of the inverter  25  outputs the first AC voltage that meets the utility power specification to the AC load (ACL). After the step S 211 , the control method returns to the step S 201 . 
     When the power supply circuit  1  determines that the utility power (Vac) is abnormal, the step S 201  is followed by a step S 213 . In the step S 213 , the battery  21  of the uninterruptible power supply  2  outputs the DC voltage to the output monitoring circuit  15  of the power supply circuit  1 . The step S 213  is followed by a step S 215 . In the step S 215 , the output monitoring circuit  15  respectively outputs the multiple DC voltages to the multiple DC loads (DCL 1  to DCL 4 ). The step S 215  is followed by a step S 217 . In the step S 217 , the battery  21  of the uninterruptible power supply  2  outputs the DC voltage to the inverter  25  of the uninterruptible power supply  2 . The step S 217  is followed by a step S 219 . In the step S 219 , the AC output terminal  251  of the inverter  25  outputs the second AC voltage that meets the utility power specification to the AC load (ACL). After the step S 219 , the control method returns to the step S 201 . 
     For example, when the AC utility power is normal, the power supply circuit  1  provides the multiple DC voltage signals with different volts to a host of a personal computer system, and the uninterruptible power supply  2  provides the first AC voltage that meets the utility power specification to a display screen. When the AC utility power is abnormal, the battery  21  of the uninterrupted power circuit  2  respectively supplies the power to the power supply circuit  1  and the inverter  25  of the uninterrupted power circuit  2 . After the power supply circuit  1  receives the power from the battery  21 , the multiple DC-DC converters of the power supply circuit  1  convert the power from the battery  21  into the multiple DC voltage signals with different volts, and respectively provide the DC voltage signals with different volts to the host of the personal computer system. After the inverter  25  receives the power from the battery  21 , the inverter  25  outputs the second AC voltage that meets the utility power specification to the display screen. 
       FIG.  3    is a functional block diagram of a backup power supply system according to a second embodiment of the present disclosure. The difference between a backup power supply system A 2  in  FIG.  3    and the backup power supply system A 1  in  FIG.  1    is that the backup power supply system A 2  further comprises an auxiliary power circuit  117 . The auxiliary power circuit  117  is connected to the output terminal of the full-wave rectifier circuit  103  and the input terminal of the control circuit  109 . When the utility power (Vac) is normal, the full-wave rectifier circuit  103  supplies the power to the auxiliary power circuit  117 . When the utility power (Vac) is abnormal, the battery  21  of the uninterruptible power supply  2  supplies the power to the auxiliary power circuit  117 , and the function of the auxiliary power circuit  117  is to supply the power to the control circuit  109  and to output a standby voltage. A value of the standby voltage can be, for example, 5 volt. 
       FIG.  4    is flowchart of a control method of the backup power supply system in  FIG.  3   . Referring to  FIG.  4   , in a step S 401 , the power supply circuit  1  determines whether or not the utility power (Vac) is normal. When the utility power is normal, the step S 401  is followed by a step S 403 . In the step S 403 , the full-wave rectifier circuit  103  supplies the power to the auxiliary power circuit  117 . The step S 403  is followed by a step S 405 . In the step S 405 , the auxiliary power circuit  117  supplies the power to the control circuit  109 . The step S 405  is followed by a step S 407 . In the step S 407 , the output monitoring circuit  115  respectively outputs the multiple DC voltages to the multiple DC loads (DCL 1  to DCL 4 ). The step S 407  is followed by a step S 409 . In the step S 409 , the output monitoring circuit  115  outputs the DC voltage to the battery management circuit  23  of the uninterruptible power supply  2 . The step S 409  is followed by a step S 411 . In the step S 411 , the battery management circuit  23  charges the battery  21  of the uninterruptible power supply  2 . The step S 411  is followed by a step S 413 . In the step S 413 , the battery  21  outputs the DC voltage to the inverter  25 . The step S 413  is followed by a step S 415 . In the step S 415 , the AC output terminal  251  of the inverter  25  outputs the first AC voltage that meets the utility power specification to the AC load (ACL). After the step S 415 , the control method returns to the step S 401 . 
     When the power supply circuit  1  determines that the utility power (Vac) is abnormal, the step S 401  is followed by a step S 417 . In the step S 417 , the battery  21  of the uninterruptible power supply  2  respectively supplies the power to the output monitoring circuit  15  of the power supply circuit  1  and the auxiliary power circuit  117 . The step S 417  is followed by a step S 419 . In the step S 419 , the output monitoring circuit  115  respectively outputs the multiple DC voltages to the multiple DC loads (DCL 1  to DCL 4 ). The step S 419  is followed by a step S 421 . In the step S 421 , the battery  21  of the uninterruptible power supply  2  outputs the DC voltage to the inverter  25  of the uninterruptible power supply  2 . The step S 421  is followed by a step S 423 . In the step S 423 , the AC output terminal  251  of the inverter  25  outputs the second AC voltage that meets the utility power specification to the AC load (ACL). The step S 423  is followed by a step S 425 . In the step S 425 , the auxiliary power circuit  117  supplies the power to the control circuit  109  and outputs the standby voltage. After the step S 425 , the control method returns to the step S 401 . 
       FIG.  5    is a flowchart of a control method of a backup power supply system according to a third embodiment of the present disclosure. Referring to  FIG.  5   , in a step S 501 , the power supply circuit  1  determines whether or not the utility power (Vac) is normal. When the utility power (Vac) is normal, the step S 501  is followed by a step S 503 . In the step S 503 , the output monitoring circuit  115  respectively outputs the multiple DC voltages to the multiple DC loads (DCL 1  to DCL 4 ). The step S 503  is followed by a step S 505 . In the step S 505 , the output monitoring circuit  115  outputs the DC voltage to the battery management circuit  23  of the uninterruptible power supply  2 . The step S 505  is followed by a step S 507 . In the step S 507 , the battery management circuit  23  determines whether or not the backup power stored in the battery  21  is lower than a lower limit. When the backup power stored in the battery  21  is lower than the lower limit, the step S 507  is followed by a step S 509 . In the step S 509 , the battery management circuit  23  supplies the power to the battery  21 . The step S 509  is followed by a step S 511 . In the step S 511 , the battery  21  supplies the power to the inverter  25 . The step S 511  is followed by a step S 513 . In the step S 513 , the AC output terminal  251  of the inverter  25  outputs the first AC voltage that meets the utility power specification to the AC load (ACL). After the step S 513 , the control method returns to the step S 501 . 
     When the backup power stored in the battery  21  is not lower than the lower limit, the step S 511  is executed. 
     When the power supply circuit  1  determines that the utility power (Vac) is abnormal, then a step S 515  is executed. In the step S 515 , the battery  21  of the uninterruptible power supply  2  outputs the DC voltage to the output monitoring circuit  115  of the power supply circuit  1 . The step S 515  is followed by a step S 517 . In the step S 517 , the output monitoring circuit  115  respectively outputs the multiple DC voltages to the multiple DC loads (DCL 1  to DCL 4 ). The step S 517  is followed by a step S 519 . In the step S 519 , the battery  21  of the uninterruptible power supply  2  outputs the DC voltage to the inverter  25  of the uninterruptible power supply  2 . The step S 519  is followed by a step S 521 . In the step S 521 , the AC output terminal  251  of the inverter  25  outputs the second AC voltage that meets the utility power specification to the AC load (ACL). After the step S 521 , the control method returns to the step S 501 . 
       FIG.  6    is a functional block diagram of a backup power supply system according to a fourth embodiment of the present disclosure. The difference between a backup power supply system A 3  in  FIG.  6    and the backup power supply system A 1  in  FIG.  1    is that the output monitoring circuit  115  further includes an AC output terminal  1155 . The AC output terminal  1155  is configured to connect to the AC load (ACL). 
     When the power supply circuit  1  determines that the utility power (Vac) is normal, the output monitoring circuit  115  of the power supply circuit  1  provides the multiple DC voltages to the DC loads (DCL 1  to DCL 4 ) respectively through the DC load connection ports  1151 A- 1151 D. The DC output terminal  1153  of the output monitoring circuit  115  outputs the DC voltage to the battery management circuit  23  of the uninterruptible power supply  2 . The AC output terminal  1155  of the output monitoring circuit  115  outputs the first AC voltage that meets the utility power specification to the AC load (ACL). After the battery management circuit  23  receives the power from the output monitoring circuit  115 , the battery management circuit  23  charges the battery  21 . 
     When the power supply circuit  1  determines that the utility power (Vac) is abnormal, the battery  21  respectively supplies the power to the output monitoring circuit  115  of the power supply circuit  1  and the inverter  25  of the uninterruptible power supply  2 . Then, the output monitoring circuit  115  outputs the multiple DC voltages to the DC loads (DCL 1  to DCL 4 ) respectively through the DC load connection ports  1151 A to  1151 D. Through the AC output terminal  251 , the inverter  25  outputs the second AC voltage that meets the utility power specification to the AC load (ACL). 
     Beneficial Effects of the Embodiments 
     In conclusion, in the backup power supply system and the control method thereof provided by the present disclosure, when a load of a power station is too large or when machinery of the power station breaks down and causes an abnormality of the utility power, the power supply circuit can provide DC voltages with different volts to various DC loads, and the uninterruptible power supply can provide the AC voltage that meets the utility power specification to the AC load, so that the AC load and each of the DC loads can continue to operate normally. 
     The foregoing description of the exemplary embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. 
     The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others skilled in the art to utilize the disclosure and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present disclosure pertains without departing from its spirit and scope.