TWI669891B - Power conversion system with abnormal energy protection and method of operating the same - Google Patents

Abstract

A power conversion system with abnormal energy protection includes a plurality of DC input power sources, a plurality of DC power converters, two output capacitors, and a protection circuit. The input side of each DC power converter is correspondingly coupled to one of the DC input power sources, and the output sides of the DC power converters are coupled in parallel with each other to form a DC output bus. The two output capacitors are coupled in series between the positive voltage terminal and the negative voltage terminal of the DC output bus. The protection circuit is coupled between the DC input power source and the two output capacitors. When an abnormality occurs in one of the two output capacitors, the protection circuit short-circuits the decoupled DC input power supply and the two output capacitors.

Description

Power conversion system with abnormal energy protection and operation method thereof

The invention relates to a power conversion system with abnormal energy protection and an operation method thereof, in particular to a power conversion system with abnormal energy protection against abnormal energy inflow and an operation method thereof.

Referring to FIG. 1, it is a circuit block diagram of a related art protection mechanism for preventing abnormal energy influx. As shown in FIG. 1, the DC output generated by the plurality of DC input power sources Vdc1~Vdcn is boosted by the corresponding DC boost converters 11A~1nA, and the capacitors 21A, 22A of the back end are supplied with power at each of the capacitors 21A. Both ends of 22A provide a stable DC output voltage to supply the power required by the back end circuit 40A, such as the inverter conversion circuit.

When a short circuit abnormality occurs in one of the capacitors 21A, 22A, for example, the capacitor 21A, since the capacitor 21A fails, all DC voltages generated by the DC input power sources Vdc1 to Vdcn will be replaced by another capacitor, that is, the capacitor 22A that is still operating normally. Withstand, in this way, the capacitor 22A will cause leakage of the electrolyte due to the damage of the capacitor 22A due to insufficient withstand voltage, which affects the operation of the entire system.

Therefore, in order to solve the above problem, the prior art mostly uses the relay switches 31A~3nA between the DC input power sources Vdc1~Vdcn and the DC boost converters 11A~1nA, thereby detecting that any one of the capacitors 22A is short-circuited abnormally or excessively. When the voltage is abnormal, the control relay switches 31A~3nA are turned off, and the DC input power sources Vdc1~Vdcn are decoupled from the DC boost converters 11A~1nA to prevent direct The continuous supply of the stream input power sources Vdc1 to Vdcn causes the capacitors 21A, 22A to be damaged, and even affects the back end circuit 40A.

However, the use of the relay switches 31A to 3nA for decoupling has the following problems and disadvantages. 1. It is not common to be able to withstand relay switches 31A~3nA up to thousands of volts. In addition, the use of relay switches 31A~3nA that can withstand high voltages will also cost more. 2. Using the protection mode of the relay switch 31A~3nA, a relay switch 31A~3nA is required on each power supply path, thus occupying a lot of space of the printed circuit board. 3, under normal operating conditions, there will be heat problems and cause inefficiency. 4, the mechanical structure of the relay switch 31A ~ 3nA, in the case of repeated action for a long time, there will be problems of reduced service life and poor reliability. 5. The use of relay switches 31A~3nA usually requires an additional pre-charge circuit, which increases the complexity of circuit design and control.

Therefore, how to design a power conversion system with abnormal energy protection and its operation method to solve the problem caused by using the relay switch as the abnormal energy inrush protection is a major problem that the inventor of the present invention has overcome and solved. .

It is an object of the present invention to provide a power conversion system with abnormal energy protection that solves the problem caused by the use of a relay switch as an abnormal energy inrush protection.

To achieve the foregoing objective, the power conversion system with abnormal energy protection proposed by the present invention comprises a plurality of DC input power sources, a complex DC power converter, two output capacitors, and a protection circuit. The input side of each DC power converter is correspondingly coupled to one of the DC input power sources, and the output sides of the DC power converters are coupled in parallel with each other to form a DC output bus. The two output capacitors are coupled in series between the positive voltage terminal and the negative voltage terminal of the DC output bus. The protection circuit is coupled to the DC input power source and the two outputs Between capacitors. When an abnormality occurs in one of the two output capacitors, the protection circuit short-circuits the decoupled DC input power supply and the two output capacitors.

The proposed power conversion system with abnormal energy protection can reduce heat loss, improve efficiency, and increase the available area of the printed circuit board and the advantages of high protection circuit expansion.

Another object of the present invention is to provide an operation method of a power conversion system with abnormal energy protection, which solves the problem caused by using a relay switch as an abnormal energy inrush protection.

The power conversion system with abnormal energy protection includes a plurality of DC input power sources, a plurality of DC power converters, and two output capacitors, and an operation method thereof. Including (a) providing a protection circuit, the protection circuit is coupled between the DC input power source and the two output capacitors; (b) detecting whether one of the two output capacitors is abnormal; and (c) when the two output capacitors are When an abnormality occurs, the control protection circuit is short-circuited to decouple the DC input power supply to generate two output capacitors.

By the proposed operation method of the power conversion system with abnormal energy protection, heat loss, efficiency can be reduced, and the available area of the printed circuit board and the advantage of the protection circuit can be increased.

In order to further understand the technology, the means and the effect of the present invention in order to achieve the intended purpose, refer to the following detailed description of the invention and the accompanying drawings. The drawings are to be considered in all respects as illustrative and not restrictive

Vdc1~Vdcn‧‧‧DC input power supply

11~1n‧‧‧1st DC power converter to nth DC power converter

20‧‧‧Protection circuit

21~2n‧‧‧protection unit

30‧‧‧DC output bus

41‧‧‧First output capacitor

42‧‧‧second output capacitor

50‧‧‧Control unit

60‧‧‧ back-end circuit

Vb+‧‧‧ positive voltage terminal

Vb-‧‧‧negative voltage terminal

Vbm‧‧‧ midpoint potential

Sv‧‧‧ voltage status signal

Sc, Sc’‧‧‧ control signals

L1~Ln‧‧‧Inductors

Q1~Qn‧‧‧Semiconductor Switch

Ri, R1~Rn‧‧‧Resistors

C1~Cn‧‧‧ capacitor

Dd, D1~Dn‧‧‧ diode

Qa‧‧‧First semiconductor switch

Qb, Qb1~Qbn‧‧‧Second semiconductor switch

11A~1nA‧‧‧DC Boost Converter

21A, 22A‧‧‧ capacitor

31A~3nA‧‧‧Relay switch

40A‧‧‧ back-end circuit

S10~S30‧‧‧Steps

Figure 1: Circuit block diagram of a protection mechanism for preventing inrush of abnormal energy from related art.

2A is a circuit block diagram of a first architecture of a power conversion system with abnormal energy protection according to the present invention.

2B is a circuit block diagram of a second architecture of a power conversion system with abnormal energy protection according to the present invention.

3 is a circuit diagram of a first embodiment of a protection circuit of a power conversion system with abnormal energy protection according to the present invention.

4 is a circuit diagram of a second embodiment of a protection circuit of a power conversion system with abnormal energy protection according to the present invention.

Fig. 5 is a circuit diagram showing a third embodiment of the protection circuit of the power conversion system with abnormal energy protection of the present invention.

Figure 6 is a circuit diagram showing a fourth embodiment of the protection circuit of the power conversion system with abnormal energy protection of the present invention.

7 is a flow chart showing the operation method of the power conversion system with abnormal energy protection according to the present invention.

The technical content and detailed description of the present invention will be described below in conjunction with the drawings.

Please refer to FIG. 2A, which is a circuit block diagram of a first architecture of a power conversion system with abnormal energy protection according to the present invention. The power conversion system with abnormal energy protection includes a plurality of DC input power sources Vdc1~Vdcn, a plurality of DC power converters 11~1n, two output capacitors 41, 42, a protection circuit 20, and a control unit 50. In an embodiment, each of the DC input power sources Vdc1 VVdcn can be a current source type power supply. The DC power source provided is, for example, but not limited to, a DC power source provided by the solar panel. For example, in the case of a solar panel, each of the DC input power sources Vdc1 to Vdcn can be composed of a plurality of solar panels connected in series.

The input side of each of the DC power converters 11 to 1n is coupled to one of the DC input power sources Vdc1 to Vdcn. The n DC power converters shown in FIG. 2A are respectively a first DC power converter 11 and a nth DC power converter 1n, which are boost DC-DC converters, and can be isolated DC conversion. Or non-isolated DC converter. The input side of the first DC power converter 11 is correspondingly coupled to the first DC input power Vdc1, and the input side of the nth DC power converter 1n is correspondingly coupled to the nth DC input power Vdcn.

Further, the output sides of the respective DC power converters 11 to 1n are coupled in parallel with each other to form a DC output bus bar 30. As shown in FIG. 2A, the output voltages of the first DC power converter 11 to the nth DC power converter 1n are coupled in parallel with each other, and one end is coupled to the positive voltage of the DC output bus 30. The other end is coupled to the negative voltage terminal Vb- of the DC output bus 30.

The two output capacitors 41 and 42 are respectively a first output capacitor 41 and a second output capacitor 42 . The two are coupled in series between the positive voltage terminal Vb+ and the negative voltage terminal Vb− of the DC output bus 30 , and the two output capacitors 41 . , 42 is coupled to the midpoint potential terminal Vbm. When a capacitor of the same specification is used as the two output capacitors 41, 42 , the voltage across the first output capacitor 41 coupled between the positive voltage terminal Vb+ and the midpoint potential terminal Vbm is coupled to the midpoint potential terminal Vbm and negative. The voltage across the second output capacitor 42 between the voltage terminals Vb- is equal. Thereby, the two output capacitors 41, 42 provide the stable DC output voltage required by the back end circuit 60.

In this embodiment, the protection circuit 20 is coupled between the DC input power sources Vdc1 VVdcn and the DC power converters 11~1n to provide a DC input power source Vdc1~ when an abnormality occurs in one of the two output capacitors 41, 42. The energy generated by Vdcn is transferred to the other of the two output capacitors, causing damage protection. Specifically, the control unit 50 is coupled to the protection circuit 20 and receives the voltage status signal Sv of the DC output bus 30, wherein the voltage status signal Sv can represent the positive voltage terminal Vb+, the negative voltage terminal Vb- or the middle of the DC output bus 30 The voltage level of any one of the potential terminals Vbm, therefore, the control unit According to the voltage state signal Sv, it can be determined whether an abnormality occurs in the voltage across the output capacitors 41, 42 such as a short circuit abnormality or an overvoltage abnormality. Wherein, when an abnormality occurs in one of the two output capacitors 41, 42, the protection circuit 20 provides a control signal Sc, and the control protection circuit 20 decouples the DC input power sources Vdc1 VVdcn from the two output capacitors 41, 42 by means of a short circuit. In order to prevent the energy generated by the DC input power supply Vdc1~Vdcn from being transmitted to the output capacitor without abnormality, the protection effect is achieved, which will be described in detail later.

Please refer to FIG. 2B , which is a circuit block diagram of a second architecture of the power conversion system with abnormal energy protection of the present invention. The main difference between the block diagram of the second architecture circuit shown in FIG. 2B and FIG. 2A is that the protection circuit 20 of the former (FIG. 2B) is coupled between the DC power converters 11~1n and the two output capacitors 41, 42. Similarly, the protection circuit 20 decouples the DC input power sources Vdc1 to Vdcn from the two output capacitors 41, 42 by means of a short circuit, so as to prevent the energy generated by the DC input power sources Vdc1 to Vdcn from being transmitted to the output capacitor without abnormality. The effect of its protection will be detailed later.

In summary, as long as the protection circuit 20 is connected between the DC input power source Vdc1~Vdcn and the power path between the two output capacitors 41, 42, the DC input power source Vdc1~Vdcn and the two output capacitors 41 can be short-circuited. , 42 decoupling to achieve the purpose of protection. Hereinafter, a specific embodiment of the protection circuit 20 will be described.

Please refer to FIG. 3, which is a circuit diagram of a first embodiment of a protection circuit for a power conversion system with abnormal energy protection according to the present invention. The protection circuit 20 is coupled between the DC input power sources Vdc1 VVdcn and the DC power converters 11~1n. The protection circuit 20 includes a plurality of protection units 21 to 2n, and each of the protection units 21 to 2n includes inductors L1 to Ln, semiconductor switches Q1 to Qn, resistors R1 to Rn, and capacitors C1 to Cn. The inductors L1~Ln are coupled in series with the inductors L1~Ln to form a series branch, wherein the series branch is coupled between the positive voltage terminal and the negative voltage terminal of the DC input power sources Vdc1 VVdcn. The capacitors C1~Cn are coupled in series with the resistors R1~Rn to form a series auxiliary branch, wherein the series auxiliary branch is coupled between the common junction and the negative voltage terminal of the inductors L1~Ln and the semiconductor switches Q1~Qn. In this embodiment, each of the semiconductor switches Q1~Qn can be a silicon controlled rectifier (SCR), a metal oxide semiconductor Metal-oxide-semiconductor field-effect transistor (MOSFET), insulated gate bipolar transistor (IGBT), bipolar junction transistor (BJT), Alternatively, other semiconductor elements having a switching function can be used as the semiconductor switch of the embodiment of the present invention.

When the control unit 50 determines that the voltage across the output capacitors 41, 42 is abnormal according to the voltage state signal Sv, such as a short circuit abnormality or an overvoltage abnormality, the control unit 50 provides a control signal Sc to control the semiconductor of each of the protection units 21~2n. The switches Q1~Qn are turned on, thereby short-circuiting the series branches, so that the current generated by the DC input power sources Vdc1~Vdcn flows through the series branch, and is decoupled from the circuit at the back end, thereby achieving the purpose of protecting the output capacitors 41, 42. In this embodiment, the inductors L1~Ln can provide suppression of inrush current, and the capacitors C1~Cn with resistors R1~Rn can provide absorption of spike voltage and surge energy. Consumption.

Please refer to FIG. 4, which is a circuit diagram of a second embodiment of a protection circuit for a power conversion system with abnormal energy protection according to the present invention. The protection circuit 20 is coupled between the DC input power sources Vdc1 VVdcn and the DC power converters 11~1n. The protection circuit 20 includes a plurality of diodes D1 to Dn, a first semiconductor switch Qa, a second semiconductor switch Qb, and a resistor Ri. The anode ends of the diodes D1 to Dn are correspondingly coupled to the positive voltage terminals of the DC input power sources Vdc1 to Vdcn, and the cathode ends of the diodes D1 to Dn are commonly coupled to form a cathode common contact. The first semiconductor switch Qa is coupled between the cathode common contact and the negative voltage terminal of one of the DC input power sources Vdc1 VVdcn. The second semiconductor switch Qb is coupled in parallel to the first semiconductor switch Qa. The resistor Ri is coupled to the cathode common contact and the first semiconductor switch Qa.

When the control unit 50 determines that the voltage across the output capacitors 41, 42 is abnormal according to the voltage state signal Sv, such as a short circuit abnormality or an overvoltage abnormality, the control unit 50 provides the control signal Sc to control the first semiconductor switch Qa of the protection circuit 20. Turning on, thereby short-circuiting the first branch where the first semiconductor switch Qa is located, so that the current generated by the DC input power source Vdc1~Vdcn flows through the first branch, and is decoupled from the circuit at the back end to achieve the protection output capacitance 41, 42 the goal of. Then, after a delay Afterwards, the control unit 50 controls the second semiconductor switch Qb to be turned on, so that the current flowing through the first branch is redirected through the second branch where the second semiconductor switch Qb is located (since the impedance of the second branch is small), In addition to continuing to maintain circuit decoupling from the back end, the heat loss due to the current flowing through the resistor Ri is also removed. The difference between the control signal Sc and the control signal Sc' shown in FIG. 4 is that the latter is a control signal generated by the control unit 50 to turn on the second semiconductor switch Qb after the delay time. Incidentally, the delay time can be generated by a hardware method such as a delay circuit or other digital or analog circuit, or a firmware or software. In the present embodiment, the resistor Ri can provide suppression of the inrush current, and each of the diodes D1 to Dn provides a forward current path to prevent current from flowing back.

Referring to FIG. 5, it is a circuit diagram of a third embodiment of a protection circuit for a power conversion system with abnormal energy protection according to the present invention. The most important difference between the third embodiment shown in FIG. 5 and the second embodiment shown in FIG. 4 is that the former provides a plurality of second semiconductor switches Qb1 to Qbn to achieve a current sharing efficiency of the short-circuit current after the delay time. The first ends of the second semiconductor switches Qb1 - Qbn are coupled to the positive voltage terminals of the DC input power sources Vdc1 - Vdcn , and the second ends of the second semiconductor switches Qb1 - Qbn are coupled together and coupled to the DC input power source Vdc1~ The negative voltage terminal of Vdcn.

Specifically, when the control unit 50 determines that the voltage across the output capacitors 41, 42 is abnormal according to the voltage state signal Sv, the control unit 50 provides the control signal Sc to control the first semiconductor switch Qa of the protection circuit 20 to be turned on, thereby making The first branch of the first semiconductor switch Qa is short-circuited, so that the current generated by the DC input power sources Vdc1~Vdcn flows through the first branch, and is decoupled from the circuit at the back end to achieve the purpose of protecting the output capacitors 41, 42. Then, after a delay time, the control unit 50 controls the second semiconductor switches Qb1 QQbn to be turned on, so that the current flowing through the first branch can be averagely changed through the second semiconductor switches Qb1~Qbn. The plurality of branches, in addition to continuing to maintain circuit decoupling from the back end, also removes the heat loss generated by the current flowing through the resistor Ri, and since the short circuit current flows evenly through the second semiconductor switches Qb1 to Qbn, Therefore, each of the second semiconductor switches Qb1 to Qbn does not have a problem of damage caused by overheating.

Please refer to FIG. 6, which is a circuit diagram of a fourth embodiment of a protection circuit for a power conversion system with abnormal energy protection according to the present invention. The protection circuit 20 is coupled between the DC power converters 11~1n and the two output capacitors 41, 42. The protection circuit 20 includes a diode Dd, a first semiconductor switch Qa, a second semiconductor switch Qb, and a resistor Ri. The anode end of the diode Dd is coupled to the positive voltage terminal Vb+ of the DC output bus 30. The first semiconductor switch Qa is coupled between a cathode end of the diode Dd and a negative voltage terminal Vb- of the DC output bus 30. The second semiconductor switch Qb is coupled in parallel to the first semiconductor switch Qa. The resistor Ri is coupled to the cathode end of the diode Dd and the first semiconductor switch Qa.

When the control unit 50 determines that the voltage across the output capacitors 41, 42 is abnormal according to the voltage state signal Sv, such as a short circuit abnormality or an overvoltage abnormality, the control unit 50 provides the control signal Sc to control the first semiconductor switch Qa of the protection circuit 20. Turning on, thereby short-circuiting the first branch where the first semiconductor switch Qa is located, so that the current generated by the conversion of the DC input power sources Vdc1 Vdcn via the DC power converters 11~1n flows through the first branch, and the circuit at the back end Decoupling achieves the purpose of protecting the output capacitors 41,42. Then, after a delay time, the control unit 50 controls the second semiconductor switch Qb to be turned on, so that the current flowing through the first branch is redirected to the second branch where the second semiconductor switch Qb is located (due to the second branch). The impedance is small), in addition to continuing to maintain circuit decoupling from the back end, the heat loss due to the current flowing through the resistor Ri is also removed. In the present embodiment, the resistor Ri can provide suppression of the inrush current, and the diode Dd provides a forward current path to prevent current from flowing back.

Please refer to FIG. 7, which is a flowchart of a method for operating a power conversion system with abnormal energy protection according to the present invention. The power conversion system with abnormal energy protection includes a plurality of DC input power sources, a plurality of DC power converters, and two output capacitors, wherein each of the DC input power sources is a DC power source provided by the current source type power source, for example, but not limited to solar energy. The DC power supply provided by the board. The operation method includes: firstly, providing a protection circuit, wherein the protection circuit is coupled between the DC input power source and the two output capacitors (S10), that is, the protection circuit can be coupled between the DC input power source and the DC power converter, or The protection circuit can be coupled between the DC power converter and the two output capacitors. Then, detecting one of the two output capacitors Whether or not an abnormality has occurred (S20). By detecting the voltage at both ends of any output capacitor, it is determined whether an abnormality occurs in one of the two output capacitors, such as a short circuit abnormality and an overvoltage abnormality. Finally, when an abnormality occurs in one of the two output capacitors, the control protection circuit short-circuits the decoupled DC input power source and the two output capacitors (S30), thereby blocking the energy generated by the DC input power source from being transmitted to the other of the two output capacitors. To avoid causing damage. That is, the control protection circuit decouples the DC input power source from the two output capacitors by means of a short circuit, so as to prevent the energy generated by the DC input power source from being transmitted to the output capacitor without abnormality, thereby achieving the protection effect.

In summary, the present invention has the following features and advantages:

1. Since the semiconductor switch is only activated when the output capacitor is abnormal, there is no loss in normal operation, and there is no problem that the relay switch has heat, so heat loss and efficiency can be reduced.

2, through the protection circuit as an abnormal energy protection, can reduce equipment costs.

3. Only need to configure a set of protection circuits to achieve abnormal energy protection, so the available area of the printed circuit board can be increased.

4. The architecture of the protection circuit coupled in parallel has the advantage of high expansion.

The above is only the detailed description and the drawings of the preferred embodiments of the present invention, but the invention is not limited thereto, and is not intended to limit the scope of the present invention. The embodiments of the present invention and the similar variations of the scope of the present invention are intended to be included in the scope of the present invention, and any one skilled in the art can readily appreciate the changes in the field of the present invention. Modifications can be covered in the scope of the patents in this case below.

Claims (15)

A power conversion system with abnormal energy protection, comprising: a plurality of DC input power sources; a plurality of DC power converters, wherein an input side of each of the DC power converters is coupled to one of the DC input power sources, each of the DC power sources An output side of the converter is directly coupled in parallel with each other to form a DC output bus; the two output capacitors are directly coupled in series between a positive voltage terminal and a negative voltage terminal of the DC output bus; and a protection a circuit, coupled between the DC input power source and the DC power converters or coupled between the DC power converters and the two output capacitors; wherein, when an abnormality occurs in one of the two output capacitors The protection circuit is short-circuited to decouple the DC input power source from the two output capacitors. The power conversion system with abnormal energy protection according to claim 1, wherein the protection circuit is coupled between the DC input power source and the DC power converters. The power conversion system with abnormal energy protection as described in claim 1, wherein the protection circuit is coupled between the DC power converter and the two output capacitors. The power conversion system with abnormal energy protection according to claim 2, wherein the protection circuit comprises a plurality of protection units, each protection unit comprises: an inductor; and a semiconductor switch coupled to the inductor in series, To form a series branch; wherein the series branch is coupled between a positive voltage terminal and a negative voltage terminal of the DC input power source. The power conversion system with abnormal energy protection according to claim 4, wherein each of the protection units further comprises: a resistor; and a capacitor coupled in series to form a series auxiliary branch; The series auxiliary branch is coupled between a common junction of the inductor and the semiconductor switch and the negative voltage terminal. The power conversion system with abnormal energy protection according to claim 2, wherein the protection circuit comprises: a plurality of diodes, wherein an anode end of each of the diodes is coupled to a positive voltage of the DC input power source a cathode end of each of the diodes is coupled to form a cathode common contact; a first semiconductor switch coupled between the cathode common contact and a negative voltage terminal of the DC input power; a second semiconductor switch coupled in parallel with the first semiconductor switch; and a resistor coupled between the cathode common contact and the first semiconductor switch. The power conversion system with abnormal energy protection according to claim 2, wherein the protection circuit comprises: a plurality of diodes, wherein an anode end of each of the diodes is coupled to a positive voltage of the DC input power source a cathode end of each of the diodes is coupled to form a cathode common contact; a first semiconductor switch coupled between the cathode common contact and a negative voltage terminal of the DC input power; a second semiconductor switch, a first end of each of the second semiconductor switches is coupled to the positive voltage terminal of the DC input power source, and a second end of each of the second semiconductor switches is coupled to the DC Input the negative voltage terminal of the power supply; and a resistor coupled between the cathode common contact and the first semiconductor switch. The power conversion system with abnormal energy protection according to claim 3, wherein the protection circuit comprises: a diode, an anode end of the diode is coupled to the positive voltage terminal of the DC output bus a first semiconductor switch coupled between a cathode end of the diode and the negative voltage terminal of the DC output bus; a second semiconductor switch coupled in parallel with the first semiconductor switch; and a resistor And connecting the cathode end of the diode to the first semiconductor switch. The power conversion system with abnormal energy protection according to any one of claims 4 to 8, wherein the semiconductor switch, the first semiconductor switch or the second semiconductor-on relationship is a controlled rectifier, a metal oxide semiconductor Any of a field effect transistor, an insulated gate bipolar transistor, or a bipolar junction transistor. The power conversion system with abnormal energy protection as described in claim 1 further includes: a control unit coupled to the protection circuit, receiving a voltage status signal of the DC output bus to determine the two output capacitors Whether an abnormality occurs; wherein when an abnormality occurs in one of the two output capacitors, the control unit provides a control signal to control the short circuit decoupling of the protection circuit. A method for operating a power conversion system with abnormal energy protection, wherein the power conversion system with abnormal energy protection comprises a plurality of DC input power sources, a plurality of DC power converters, and two output capacitors, the operation method comprising: (a) providing a protection circuit coupled between the DC input power source and the two output capacitors; (b) detecting whether an abnormality occurs in one of the two output capacitors; and (c) When an abnormality occurs in one of the two output capacitors, the protection circuit is short-circuited to decouple the DC input power source and the two output capacitors. The operating method of the power conversion system with abnormal energy protection according to claim 11, wherein the protection circuit is coupled between the DC input power source and the DC power converter, and the protection circuit includes multiple protection The unit, each of the protection units includes a series branch formed by an inductor and a semiconductor switch, wherein the series branch is coupled between a positive voltage terminal and a negative voltage terminal of the DC input power source; In the case where an abnormality occurs in one of the two output capacitors, the semiconductor switch is turned on, and energy generated by the DC input power sources is transmitted via the series branch. The operating method of the power conversion system with abnormal energy protection according to claim 11, wherein the protection circuit is coupled between the DC input power source and the DC power converter, and the protection circuit includes a plurality of a first branch formed by the diode, a resistor and a first semiconductor switch, and a second branch formed by the diode and a second semiconductor switch; in step (c), when When an abnormality occurs in one of the two output capacitors, the first semiconductor switch is turned on, and the energy generated by the DC input power sources is transmitted through the first branch, and after a delay time, the second semiconductor switch is turned on again. The energy generated by the DC input power sources is transmitted via the second branch. The operating method of the power conversion system with abnormal energy protection as described in claim 11, wherein the protection circuit is coupled to the DC input power source and the DC power converter The protection circuit includes a plurality of diodes, a first branch formed by a resistor and a first semiconductor switch, and a second branch formed by the plurality of second semiconductor switches; in step (c) When an abnormality occurs in one of the two output capacitors, the first semiconductor switch is turned on, and the energy generated by the DC input power sources is transmitted through the first branch, and the second semiconductor is turned on after a delay time. a switch that causes energy generated by the DC input power sources to be transmitted via the second branch. The method of operating a power conversion system with abnormal energy protection according to claim 11, wherein the protection circuit is coupled between the DC power converter and the two output capacitors, the protection circuit includes a diode a first branch formed by the body, a resistor and a first semiconductor switch, and a second branch formed by the diode and a second semiconductor switch; in the step (c), when the two output capacitors When an abnormality occurs, the first semiconductor switch is turned on, and the energy generated by the DC input power sources is transmitted through the first branch. After a delay time, the second semiconductor switch is turned on to enable the DC input. The energy generated by the power source is transmitted via the second branch.