Power supply circuit of energy storage system and energy storage converter

Abstract

The utility model provides a power supply circuit of an energy storage system and an energy storage converter. The power supply circuit comprises a first branch circuit, wherein the first branch circuit comprises a first circuit breaker connected between the positive power supply end of the energy storage system and the positive input end of a load of the energy storage system; the second branch circuit and the first branch circuit are connected in parallel between the positive power supply end and the positive input end, the second branch circuit comprises a charging protection module, a pre-charging relay and a pre-charging resistor which are connected in series, and the second branch circuit forms a pre-charging loop of the energy storage system; and a pre-charging path is formed by closing the pre-charging relay in the pre-charging process, and the charging protection module disconnects the pre-charging path in response to the over-input voltage of the second branch circuit and / or the over-current of the second branch circuit.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of energy storage, in particular, to a power supply circuit of an energy storage system and an energy storage converter. BACKGROUND

[0002] The existing energy storage system usually includes an energy storage device such as a battery pack or a super capacitor. In order to prolong the service life of the energy storage device and ensure its safe operation, it is necessary to pre-charge it at the initial stage of power-on, that is, to control the current to gradually charge to reduce the damage of the impact current to the energy storage device and other electrical elements.

[0003] However, the existing pre-charge scheme has problems such as complex design, high cost, poor control effect, etc. In addition, the existing technical scheme lacks an effective protection module. During the pre-charge process, the excessively high charging current may cause the capacitor, battery or other elements to heat up, resulting in the risk of overheating and burning, thereby affecting the safety and reliability of the system. UTILITY MODEL CONTENT

[0004] One of the purposes of the present disclosure is to provide a power supply circuit capable of reducing the risk of overheating and burning of the capacitor, battery or other elements of the energy storage system caused by excessively high charging current.

[0005] One of the purposes of the present disclosure is to provide a power supply circuit capable of providing stable current during the pre-charge phase to ensure the safe and stable operation of the energy storage system.

[0006] According to a first aspect of the present disclosure, a power supply circuit of an energy storage system is provided, the power supply circuit comprising: a first branch comprising a first circuit breaker connected between a positive power supply end of the energy storage system and a positive input end of a load of the energy storage system; a second branch connected in parallel with the first branch between the positive power supply end and the positive input end, and the second branch comprising a charging protection module, a pre-charge relay and a pre-charge resistor connected in series, wherein the second branch forms a pre-charge circuit of the energy storage system, and a pre-charge path is formed by the closure of the pre-charge relay during the pre-charge process, and the charging protection module disconnects the pre-charge path in response to an over-input voltage of the second branch and / or an overcurrent of the second branch.

[0007] According to an embodiment of the present disclosure, the first circuit breaker can be directly connected to the positive power supply end.

[0008] According to an embodiment of the present disclosure, the input end of the charging protection module can be connected to the positive power supply end, the output end of the charging protection module can be connected to the first power supply end of the pre-charge relay, the second power supply end of the pre-charge relay can be connected to the first end of the pre-charge resistor, and the second end of the pre-charge resistor can be connected to the positive input end.

[0009] According to an embodiment of the present disclosure, the power supply circuit can further include a control module, the controlled terminal of the first breaker is electrically connected with the control module, and the controlled terminal of the pre-charge relay is connected to the control module, and the control module controls the pre-charge relay to be closed and the first breaker to be opened during the pre-charge process.

[0010] According to an embodiment of the present disclosure, the power supply circuit can further include a voltage detector and a current detector, the voltage detector detects the voltage at the positive input terminal, and the current detector detects the pre-charge current of the second branch.

[0011] According to an embodiment of the present disclosure, the current detector can be a current transformer, and the current transformer is arranged on the second branch.

[0012] According to an embodiment of the present disclosure, the pre-charge resistor can include a first pre-charge resistor and a second pre-charge resistor connected in series with each other, and the power supply circuit further includes a switching circuit connected in parallel with the first pre-charge resistor or the second pre-charge resistor.

[0013] According to an embodiment of the present disclosure, the power supply circuit can further include a switching circuit, the pre-charge resistor includes a first pre-charge resistor, a second pre-charge resistor and a third pre-charge resistor, the first pre-charge resistor and the second pre-charge resistor are connected in parallel with each other, and the third pre-charge resistor is connected in parallel with the first pre-charge resistor or the second pre-charge resistor after being connected in series with the switching circuit.

[0014] According to an embodiment of the present disclosure, the switching circuit can include a controllable switch and a driver thereof, and the driver is used to control the closing or opening of the controllable switch.

[0015] According to a second aspect of the present disclosure, a power supply circuit for an energy storage system is provided. BRIEF DESCRIPTION OF DRAWINGS

[0016] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the drawings.

[0017] Figure 1 is a circuit diagram of a power supply circuit of an energy storage system according to an embodiment of the present disclosure;

[0018] Figure 2 is a circuit diagram of a configuration of a pre-charge resistor according to a first embodiment of the present disclosure;

[0019] Figure 3 is a circuit diagram of a configuration of a pre-charge resistor according to a second embodiment of the present disclosure;

[0020] Figure 4 is a circuit diagram of a configuration of a pre-charge resistor according to a third embodiment of the present disclosure. DETAILED DESCRIPTION

[0021] The following detailed description is presented to aid in understanding the methods, devices, and / or systems described herein. The sequence of operations described in the following detailed description is an example only and is not limiting, except as can be expressly recited in a claim. Equivalents can be performed in an alternative order, or sequence, or omitted, except as can be expressly recited in a claim. Additionally, descriptions of well-known functionality and constructions can be omitted for the sake of clarity and conciseness.

[0022] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms, such as "tertiary" are to be interpreted as being consistent with their meaning in the context of the relevant art and this disclosure and are not to be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0023] The same reference numbers in different drawings represent the same elements (e.g., components, steps, and the like). Numbers in the drawings can be omitted or simplified, and the same reference numbers in the preceding embodiments can be omitted in the following embodiments. In addition, the technical features described in different or the same embodiments can be combined in any manner as long as the combined embodiments or technical solutions are complete and capable of solving the technical problems of the present application or achieving the technical effects described or not described in the present disclosure but can be determined according to the complete technical solutions described above. It should be noted that these embodiments and their features can be combined with each other as long as there is no conflict between the embodiments. Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system described above and the related description can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0024] The present disclosure connects a threshold switching circuit (e.g., a low-voltage starting switch component) in the input circuit of a direct-current power module (i.e., a switching power supply) of a power supply circuit of an energy storage system, which is capable of adjusting the starting voltage of the switching power supply circuit. As an example, the threshold switching circuit can be deployed in the input voltage protection circuit of the switching power supply and / or the starting circuit of the switching power supply. The following will be described in detail in conjunction with the drawings of the present disclosure.

[0025] Figure 1 is a circuit diagram of a power supply circuit of an energy storage system according to an embodiment of the present disclosure, Figure 2 is a circuit diagram of a configuration of a pre-charge resistor according to a first embodiment of the present disclosure, Figure 3 is a circuit diagram of a configuration of a pre-charge resistor according to a second embodiment of the present disclosure, Figure 4 is a circuit diagram of a configuration of a pre-charge resistor according to a third embodiment of the present disclosure.

[0026] The power supply circuit of the energy storage system according to the embodiments of the present disclosure can include a first branch 10 and a second branch 20.

[0027] The first branch 10 is a positive branch, and the input end of the first branch can be connected to a positive power supply end (i.e., power supply +). The first branch 10 can include a first circuit breaker 11 connected between the positive power supply end of the energy storage system and the positive input end (load +) of the load of the energy storage system.

[0028] The first branch 10 can form a closed loop after pre-charging is completed, thereby normally supplying power to the load. The first branch 10 can include the first circuit breaker 11 and can not include a relay (i.e., a main relay). The first circuit breaker 11 can be directly connected to the positive power supply end (power supply +), thereby simplifying the overall topology by omitting the main relay in the first branch 10. Instead of the function of the main relay, it can be implemented by an existing circuit breaker or other protection device. For example, the first circuit breaker 11 can be closed after pre-charging is completed, cutting out the pre-charging loop, ensuring that the main circuit works normally, and supplying power to the load through the power supply. The first branch 10 can serve as a normal charging loop.

[0029] In addition to the first circuit breaker 11, the first branch 10 can also include components such as a fuse. When a charging anomaly occurs, for example, an overvoltage or overcurrent occurs, the first branch 10 can be disconnected in a very short time. As an example, the first circuit breaker 11 can be a molded case circuit breaker (MCCB), for example, the first circuit breaker 11 can be a Schneider Electric NSX series circuit breaker, and the fuse in the first branch 10 can be a high-voltage fuse, for example, a Siemens HPM series fuse.

[0030] The first circuit breaker 11 can implement overload protection, short circuit protection, and instantaneous tripping protection. Specifically, when the current exceeds the set overload threshold, the first circuit breaker 11 can disconnect the circuit within a certain time to prevent overheating and damage, in addition, when a short circuit current is detected, the first circuit breaker 11 can disconnect the circuit in a very short time (milliseconds) to prevent serious electrical faults, and further, when the current exceeds the instantaneous tripping threshold, the first circuit breaker 11 can immediately disconnect the circuit to provide rapid protection. The above protection functions and on-off control can also be controlled separately by the control module 30.

[0031] As an example, Figure 1 The power supply shown in the middle of the figure comes from an external power supply device, which is connected to the power supply circuit through "power supply +" and "power supply -", and supplies power to the load of the entire energy storage system.

[0032] The power supply ports (positive power supply terminal (power +) and negative power supply terminal (power -)) can be connected to an external power source, such as a battery pack, a generator, or other power supply device. The load of the energy storage system can include a super capacitor, a battery pack, and the like.

[0033] Referring to Figure 1 The second branch 20 can be connected in parallel with the first branch 10 between the positive power supply terminal (power +) and the positive input terminal (load +), and the second branch 20 can include a charging protection module 21, a pre-charge relay 22, and a pre-charge resistor 23 connected in series.

[0034] In addition, the power supply circuit of the energy storage system according to the embodiments of the present disclosure can further include a control module 30 and / or a switching circuit for adjusting the resistance value of the pre-charge variable resistor.

[0035] Although not shown, the charging protection module 21 can include a circuit breaker (e.g., a second circuit breaker) and can also include a fuse. The circuit breaker and the fuse in the charging protection module 21 of the second branch 20 can be the same as those in the first branch 10. As an example, the second circuit breaker can implement overload protection, short circuit protection, and instantaneous tripping protection. When the current exceeds a set overload threshold, the circuit breaker will disconnect the circuit within a certain time to prevent overheating and damage, in addition, when a short circuit current is detected, the circuit breaker will disconnect the circuit (i.e., the pre-charge loop) within a very short time (milliseconds) to prevent serious electrical faults, and further, when the current exceeds the instantaneous tripping threshold, the circuit breaker will immediately disconnect the circuit to provide rapid protection. The protection functions and on-off control here can also be controlled separately by the control module 30.

[0036] As an example, the charging protection module 21 can further include at least one of a current detector (or current sensor), a voltage detector (or voltage sensor), a temperature sensor, and a protection circuit.

[0037] The current detector can monitor the current in the second branch in real time to ensure that the current does not exceed a safety threshold. The current detector here can be a current transformer, a Hall effect sensor, a shunt, etc. Similarly, the voltage detector can monitor the voltage of the second branch or the voltage of the load in real time to ensure that these voltages are within a safe range, and when an overvoltage or an under-voltage (input under-voltage) is detected, a protection mechanism can be triggered to prevent damage to the energy storage device and the circuit.

[0038] The temperature sensor can detect the ambient temperature or monitor the temperature of the related devices in the energy storage system to ensure that the temperature is within a safe range, and when an excessively high temperature is detected, a protection mechanism can be triggered to prevent damage or fire caused by overheating.

[0039] The voltage detector and the temperature sensor herein can also be considered as part of the power supply circuit. Thus, the power supply circuit further comprises a voltage detector and a current detector. The voltage detector can detect the voltage at the positive input terminal, and the current detector can detect the pre-charge current of the second branch. The current detector can be a current transformer, and the current transformer is arranged on the second branch.

[0040] The protection circuit can provide additional protection measures to ensure the safety of the system in extreme cases. As an example, the protection circuit can comprise an over-voltage protection circuit, an under-voltage protection circuit, etc.

[0041] The charge protection module 21 can disconnect the pre-charge path in response to an over-input voltage of the second branch and / or an over-current of the second branch. In addition, the charge protection module 21 can also disconnect the pre-charge path in response to an under-voltage of the second branch.

[0042] Taking the under-voltage protection circuit as an example, the under-voltage protection circuit can obtain an input voltage, for example, a high voltage can be converted into a low voltage suitable for detection by using a voltage transformer or a voltage dividing resistor network, and then the noise and ripple in the input voltage signal are filtered out by a filter circuit. After obtaining the input voltage, the input voltage is compared with a preset under-voltage threshold value by a comparator, and the comparison result can be output to the control module 30. The control module 30 performs corresponding control according to the comparison result, so as to cut off the second branch and / or the first branch when the under-voltage threshold value is lower than the under-voltage threshold value.

[0043] Referring to Figure 1 , the second branch 20 can form a pre-charge circuit of the energy storage system, and a pre-charge path is formed by the closure of the pre-charge relay 22 during the pre-charge process. As an example, the voltage across the super capacitor or the like can be detected by the voltage detector, and when the voltage detection value is less than a preset threshold value, the pre-charge relay 22 can be closed for pre-charge. During the pre-charge process, the first branch 10 is disconnected, and the second branch 20 is closed. During the normal charging process, the first branch 10 is closed, and the second branch 20 is disconnected.

[0044] Referring to Figure 1 , the input terminal of the charge protection module 21 can be connected to the positive power supply terminal (power supply +), the output terminal of the charge protection module 21 can be connected to the first power supply terminal of the pre-charge relay 22, the second power supply terminal of the pre-charge relay 22 can be connected to the first terminal of the pre-charge resistor 23, and the second terminal of the pre-charge resistor 23 can be connected to the positive input terminal (load +).

[0045] The connection mode of each component in the second branch 20 is not limited in particular, and as an example, the input end of the charge protection module 21 can be connected to the positive power supply end (power supply +), the output end of the charge protection module 21 can be connected to the first end of the pre-charge resistor 23, the second end of the pre-charge resistor 23 can be connected to the first power supply end of the pre-charge relay 22, and the second power supply end of the pre-charge relay 22 can be connected to the positive input end (load +).

[0046] With reference to Figure 1 , the power supply circuit according to the embodiments of the present disclosure further includes a control module 30, the controlled terminal of the first circuit breaker 11 can be electrically connected to the control module 30, and the controlled terminal of the pre-charge relay 22 can be connected to the control module, and the control module 30 can control the pre-charge relay 22 to be closed and the first circuit breaker 11 to be opened during the pre-charge process.

[0047] The pre-charge relay 22 can have different voltage levels such as 5V, 12V, etc. The pre-charge relay 22 relay can be a normally open (NO) or a normally closed (NC) relay.

[0048] The controlled terminal of the pre-charge relay 22 can be connected to the digital output pin of the control module 30, and the control module 30 can output a control signal for controlling the pre-charge relay 22 to be turned on and turned off through the digital output pin. The power supply pin (first power supply end or first input end) of the pre-charge relay 22 can be connected to the relay power supply, and the ground terminal (second power supply end or second output end) of the pre-charge relay 22 can be grounded with the ground terminal of the control module 30.

[0049] In addition, the pre-charge relay 22 can further include a feedback terminal, and the control module 30 can determine whether the pre-charge relay 22 is normally closed or opened according to the feedback terminal. For example, for a normally open relay, if the feedback signal line is connected between the power supply and the normally open contact of the relay, the voltage on the feedback signal line is low (usually 0V). When the contact of the normally open relay is closed to form a path, if the feedback signal line is connected between the power supply and the normally open contact of the relay, the voltage on the feedback signal line is high (usually the power supply voltage, such as 5V or 12V).

[0050] With reference to Figure 2 , the pre-charge resistor 23 can include a first pre-charge resistor 231 and a second pre-charge resistor 232 connected in series with each other, and the power supply circuit according to the embodiments of the present disclosure further includes a switching circuit 230 connected in parallel with the first pre-charge resistor 231 or the second pre-charge resistor 232.

[0051] With reference to Figure 1 and Figure 2, one end (A end) of the first pre-charge resistor 231 can serve as the first end of the pre-charge resistor 23 and can be connected to the second end of the pre-charge relay 22, and one end (B end) of the second pre-charge resistor 232 can serve as the second end of the pre-charge resistor 23 and can be connected to the positive input end of the load (load+).

[0052] With reference to Figure 2 , the switch circuit 230 can be connected in parallel with the second pre-charge resistor 232, and the switch circuit 230 can be switched in and out to change the resistance value of the pre-charge resistor 23, so as to match different charging currents. Specifically, when the switch circuit 230 is switched in, the resistance value of the pre-charge resistor 23 is equal to the resistance value of the first pre-charge resistor 231, and when the switch circuit 230 is switched out, the resistance value of the pre-charge resistor 23 is equal to the sum of the resistance value of the first pre-charge resistor 231 and the resistance value of the second pre-charge resistor 232.

[0053] The switch circuit can include a controllable switch and a driver thereof, and the driver of the controllable switch can be in a mechanical control mode or an electronic control mode, and the driver is used to control the closing or opening of the controllable switch. The electronic control mode can be local wired signal control or remote wireless signal control. As an example, the switch circuit can be a single-pole single-throw, single-pole multi-throw, or multi-pole multi-throw mechanical switch, or a relay switch. When the switch is short-circuited by an electronic control mode, the control module 30 can control the state of the switch in the switch circuit, for example, the control module 30 can dynamically adjust the value of the pre-charge resistor according to the starting current demand of different energy storage devices.

[0054] For example, with reference to Figure 2 When a larger starting current is required, the control module 30 can control the controllable switch in the switch circuit to be closed, so that the second pre-charge resistor 232 is short-circuited, and at this time the pre-charge resistor can have a relatively small resistance value. When a larger starting current is required, the control module 30 can control the controllable switch in the switch circuit to be opened, so that the second pre-charge resistor 232 is connected to the circuit, and at this time the pre-charge resistor can have a relatively large resistance value.

[0055] With reference to Figure 3 The power supply circuit according to the embodiments of the present disclosure can further include a switch circuit 230, and the pre-charge resistor 23 can include a first pre-charge resistor 231, a second pre-charge resistor 232, and a third pre-charge resistor 233. The first pre-charge resistor 231 and the second pre-charge resistor 232 can be connected in series with each other, and the third pre-charge resistor 233 is connected in series with the switch circuit 230 and then connected in parallel with the second pre-charge resistor 232. As an example, the third pre-charge resistor 233 can also be connected in series with the switch circuit 230 and then connected in parallel with the first pre-charge resistor 231.

[0056] With reference toFigure 1 and Figure 3 One end (A end) of the first pre-charge resistor 231 can serve as the first end of the pre-charge resistor 23 and can be connected to the second end of the pre-charge relay 22, and one end (B end) of the second pre-charge resistor 232 can serve as the second end of the pre-charge resistor 23 and can be connected to the positive input end (load+) of the load.

[0057] For example, when a larger starting current is needed, the control module 30 can control the controllable switch in the switch circuit to be closed, so that the third pre-charge resistor 233 is connected in parallel with the second pre-charge resistor 232, at this time, the pre-charge resistor 23 can have a relatively small resistance value, at this time, the resistance value of the pre-charge resistor is the sum of the parallel resistance of the second pre-charge resistor 232 and the third pre-charge resistor 233 and the resistance of the first pre-charge resistor 231. When a larger starting current is needed, the control module 30 can control the controllable switch in the switch circuit to be closed, so that the third pre-charge resistor 233 is not connected in the circuit, at this time, the pre-charge resistor 23 can have a relatively large resistance value, at this time, the resistance value of the pre-charge resistor is the sum of the resistance values of the first pre-charge resistor 231 and the second pre-charge resistor 232.

[0058] Referring to Figure 4 According to the power supply circuit of the embodiment of the present disclosure, the pre-charge resistor can further include a first pre-charge resistor 231, a second pre-charge resistor 232 and a third pre-charge resistor 233, the first pre-charge resistor 231 and the second pre-charge resistor 232 can be connected in parallel with each other, and the third pre-charge resistor 233 is connected in series with the switch circuit 230 and then connected in parallel with the first pre-charge resistor 231 or the second pre-charge resistor 232.

[0059] Referring to Figure 1 and Figure 4 One end (A end) of the first pre-charge resistor 231 can serve as the first end of the pre-charge resistor 23 and can be connected to the second end of the pre-charge relay 22, and one end (B end) of the first pre-charge resistor 231 can serve as the second end of the pre-charge resistor 23 and can be connected to the positive input end (load+) of the load.

[0060] For example, when a larger starting current is required, the control module 30 can control the controllable switch in the switch circuit to close, so that the third pre-charge resistor 233 is connected in parallel with the second pre-charge resistor 232, at which time the pre-charge resistor can have a relatively small resistance value, at which time the resistance value of the pre-charge resistor is the parallel resistance value of the first pre-charge resistor 231, the second pre-charge resistor 232, and the third pre-charge resistor 233. When a larger starting current is required, the control module 30 can control the controllable switch in the switch circuit to open, so that the third pre-charge resistor 233 is not connected in the circuit, at which time the pre-charge resistor can have a relatively large resistance value, at which time the resistance value of the pre-charge resistor is the parallel resistance value of the first pre-charge resistor 231 and the second pre-charge resistor 232.

[0061] Figures 2 to 4 The switch circuits shown in FIGS. 1-3 can have the same configuration and control method.

[0062] In addition, the pre-charge resistor 23 can also include three or more pre-charge resistors connected in series with each other, i.e., a first pre-charge resistor, a second pre-charge resistor, and a third pre-charge resistor. The switch circuit of the power supply circuit of the present disclosure can be connected in parallel to one of the first pre-charge resistor, the second pre-charge resistor, and the third pre-charge resistor. In addition, the switch circuit of the present disclosure can also be multiple, and each pre-charge resistor can be connected in parallel with a switch circuit.

[0063] The above-described ways of changing the pre-charge resistor are merely examples, and the present disclosure is not limited thereto. As an example, the resistance value of the pre-charge resistor connected in the circuit can also be changed by a single-pole multi-throw switch, a multi-pole multi-throw switch, or the like. The energy storage system or the energy storage converter of the present disclosure can include the above-described power supply circuit.

[0064] The control module 30 according to the embodiments of the present disclosure can be a programmable logic controller. The control module 30 can be used to control the various switching devices in the power supply circuit. As an example, the control module 30 can control the pre-charge relay 22 to open and the first circuit breaker 11 to close, so as to disconnect the second branch and connect the first branch, according to the monitored load voltage (e.g., the voltage across the supercapacitor) and the input voltage (the voltage of the positive power supply terminal), and when the voltage of the load is greater than or equal to eighty percent of the input voltage and less than the input voltage. As an example, the control module 30 can also determine the degree of completion of the pre-charge according to the size of the detected current of the second branch, so as to control the on-off of the first branch and the second branch.

[0065] As an example, the control module 30 can also determine whether overcurrent exists according to the detected current of the second branch or the main circuit, and when the detected current exceeds a preset threshold (indicating that overcurrent is generated), the control module 30 can control the pre-charge relay 22 or the breaker in the charge protection circuit to be disconnected, so as to disconnect the second branch. In addition, the control module 30 can also control the on-off of the pre-charge relay 22 according to the ambient temperature or the temperature of the related equipment monitored by the temperature sensor. For example, when the ambient temperature monitored by the temperature sensor exceeds a preset threshold, the control module 30 can control the pre-charge relay to be disconnected to stop pre-charging, and also control the first breaker 11 to be disconnected.

[0066] As an example, the power supply circuit of the present disclosure can be installed inside or outside the PCS of the energy storage system, preferably, the power supply circuit of the energy storage system can be installed inside the PCS, so as to have higher system integration.

[0067] The power supply circuit according to the embodiments of the present disclosure can reduce the risk of overheat and combustion of the capacitor, battery or other elements of the energy storage system caused by excessively high charging current.

[0068] The power supply circuit according to the embodiments of the present disclosure can provide stable current in the pre-charging stage to ensure the safe and stable operation of the energy storage system.

[0069] It should be understood that the present disclosure is not limited to the precise construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A power supply circuit for an energy storage system, characterized by, The power supply circuit comprises: a first branch comprising a first circuit breaker connected between a positive power supply end of an energy storage system and a positive input end of a load of the energy storage system; a second branch connected in parallel with the first branch between the positive power supply end and the positive input end, and comprising a charging protection module, a pre-charge relay and a pre-charge resistor connected in series, wherein the second branch forms a pre-charge loop of the energy storage system, and a pre-charge path is formed by closure of the pre-charge relay during a pre-charge process, and the charging protection module opens the pre-charge path in response to an over-input voltage of the second branch and / or an over-current of the second branch.

2. The power supply circuit of an energy storage system of claim 1, wherein, The first circuit breaker is directly connected to the positive power supply end.

3. The power supply circuit of an energy storage system of claim 1, wherein, An input end of the charging protection module is connected to the positive power supply end, an output end of the charging protection module is connected to a first power supply end of the pre-charge relay, a second power supply end of the pre-charge relay is connected to a first end of the pre-charge resistor, and a second end of the pre-charge resistor is connected to the positive input end.

4. The power supply circuit of an energy storage system according to any one of claims 1 to 3, characterized in that, The power supply circuit further comprises a control module, a controlled terminal of the first circuit breaker is electrically connected to the control module, and a controlled terminal of the pre-charge relay is connected to the control module, the control module controls the pre-charge relay to be closed and controls the first circuit breaker to be opened during a pre-charge process.

5. The power supply circuit of an energy storage system according to claim 4, wherein, The power supply circuit further comprises a voltage detector and a current detector, the voltage detector detects a voltage at the positive input end, and the current detector detects a pre-charge current of the second branch.

6. The power supply circuit of an energy storage system according to claim 5, wherein, The current detector is a current transformer, and the current transformer is arranged on the second branch.

7. The power supply circuit of an energy storage system of claim 1, wherein, The pre-charge resistor comprises a first pre-charge resistor and a second pre-charge resistor connected in series with each other, and the power supply circuit further comprises a switching circuit connected in parallel with the first pre-charge resistor or the second pre-charge resistor.

8. The power supply circuit of an energy storage system of claim 1, wherein, The power supply circuit further comprises a switching circuit, the pre-charge resistor comprises a first pre-charge resistor, a second pre-charge resistor and a third pre-charge resistor, the first pre-charge resistor and the second pre-charge resistor are connected in parallel with each other, and the third pre-charge resistor is connected in parallel with the first pre-charge resistor or the second pre-charge resistor after being connected in series with the switching circuit.

9. The power supply circuit of an energy storage system according to claim 7 or 8, characterized in that, The switching circuit comprises a controllable switch and a driver thereof, and the driver is used to control closure or opening of the controllable switch.

10. An energy storage converter, characterized by The energy storage converter comprises the power supply circuit according to any one of claims 1 to 9.

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