Voltage polarity detection circuit for dc input of energy storage converter

Abstract

The application discloses a voltage polarity detection circuit for a direct-current input end of an energy storage converter, which comprises an energy storage converter control board and a detection module, wherein one end of the detection module is electrically connected with the energy storage converter control board, and the other end of the detection module is connected with a direct-current input end of the energy storage converter; a positive electrode of an energy storage battery cluster is connected with a positive electrode of a direct-current input port of the energy storage converter, and a negative electrode of the energy storage battery cluster is connected with a negative electrode of the direct-current input port of the energy storage converter; or, the positive electrode of the energy storage battery cluster is connected with the negative electrode of the direct-current input port of the energy storage converter, and the negative electrode of the energy storage battery cluster is connected with the positive electrode of the direct-current input port of the energy storage converter. The circuit can accurately detect the voltage polarity of the direct-current input port of the energy storage converter, and the control board of the energy storage converter can perform corresponding operation or fault alarm according to the voltage polarity of the direct-current input port fed back by the detection circuit.

Description

Technical Field

[0001] This application relates to the field of power storage technology, and in particular to a voltage polarity detection circuit at the DC input terminal of an energy storage converter. Background Technology

[0002] Energy storage converters and energy storage batteries are key components of electrochemical energy storage systems. The energy storage converter acts as a bridge connecting the power grid (or load) and the energy storage battery. When the energy storage battery cluster is connected to the DC input port of the energy storage converter, the positive and negative terminals of the energy storage battery cluster must be connected one-to-one with the positive and negative terminals of the DC input port of the energy storage converter to ensure that the voltage polarity of the DC input port of the energy storage converter is positive. This is a basic requirement for the normal operation of the energy storage system.

[0003] Therefore, energy storage converters must typically have a DC input port voltage polarity detection function to detect the voltage polarity of the DC input port when the energy storage battery cluster is connected to the energy storage converter. The control board of the energy storage converter will then perform corresponding operations or fault alarms based on the voltage polarity of the DC input port fed back by the detection circuit. Utility Model Content

[0004] This application provides a voltage polarity detection circuit for the DC input terminal of an energy storage converter, which can accurately detect the voltage polarity of the DC input port of the energy storage converter, and the control board of the energy storage converter performs corresponding operations or fault alarms based on the voltage polarity of the DC input port fed back by the detection circuit.

[0005] The embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, embodiments of this application provide a voltage polarity detection circuit for the DC input terminal of an energy storage converter, wherein the circuit includes: an energy storage converter control board and a detection module, the energy storage converter control board being electrically connected to one end of the detection module, and one end of the detection module being connected to the DC input terminal of the energy storage converter;

[0007] The positive terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter.

[0008] Alternatively, the positive terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter.

[0009] In some embodiments, the detection module includes a diode and an optocoupler.

[0010] In some embodiments, the energy storage converter control board includes an FPGA module and an MCU module, wherein the MCU module is communicatively connected to the FPGA module.

[0011] In some embodiments, when the positive terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter and the negative terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter, the energy storage converter control board is further used for...

[0012] The system receives the high-level feedback signal FB_U and the low-level feedback signal FB_D output by the detection module.

[0013] In some embodiments, the MCU module is configured to determine that the voltage polarity of the DC input terminal is positive based on the feedback signal FB_U being a high-level signal and the feedback signal FB_D being a low-level signal.

[0014] In some embodiments, when the positive terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter, the energy storage converter control board is further used for...

[0015] The receiver detects the high-level feedback signal FB_D and the low-level feedback signal FB_U output by the detection module.

[0016] In some embodiments, the feedback signals of the detection module always maintain opposite level states, with one feedback signal being high and the other being low.

[0017] In some embodiments, the detection module includes two detection module circuits with identical circuit structures, which are connected in series.

[0018] In some embodiments, when the energy storage battery cluster is connected to the DC input port of the energy storage converter, the positive and negative terminals of the energy storage battery cluster are respectively connected to the positive and negative terminals of the DC input port of the energy storage converter.

[0019] When the voltage polarity detection feedback state of the DC input port of the energy storage converter is positive, the energy storage converter can switch to cold standby, hot standby or running state.

[0020] When the voltage polarity detection feedback status of the DC input port of the energy storage converter is negative, the energy storage converter reports a DC input port voltage polarity abnormality fault and enters a fault protection state.

[0021] The at least one technical solution adopted in this application embodiment can achieve the following beneficial effects: The circuit includes: an energy storage converter control board and a detection module. One end of the energy storage converter control board is electrically connected to one end of the detection module, and one end of the detection module is connected to the DC input terminal of the energy storage converter. The positive terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter; or, the positive terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter. Through the above circuit, the voltage polarity of the DC input port of the energy storage converter can be accurately detected, and the control board of the energy storage converter performs corresponding operations or fault alarms based on the voltage polarity of the DC input port fed back by the detection circuit. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0023] Figure 1 This is a schematic diagram of the internal structure of the voltage polarity detection circuit at the DC input terminal of the energy storage converter in this embodiment of the application.

[0024] Figure 2 This is a schematic diagram of the voltage polarity detection circuit at the DC input terminal of the energy storage converter in one of the embodiments of this application;

[0025] Figure 3 This is a schematic diagram (part two) of the circuit principle of the voltage polarity detection circuit at the DC input terminal of the energy storage converter in this embodiment of the application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0027] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0028] This application provides a voltage polarity detection circuit at the DC input terminal of an energy storage converter, such as... Figure 1The diagram shows the internal structure of the voltage polarity detection circuit at the DC input terminal of the energy storage converter in this embodiment of the application. The circuit includes: an energy storage converter control board 1010 and a detection module 1020. One end of the energy storage converter control board 1010 is electrically connected to one end of the detection module 1020, and one end of the detection module 1020 is connected to the DC input terminal of the energy storage converter. The positive terminal of the energy storage battery cluster 200 is connected to the positive terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter; or, the positive terminal of the energy storage battery cluster 200 is connected to the negative terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter.

[0029] When the energy storage battery cluster is connected to the DC input port of the energy storage converter, the control board of the energy storage converter accurately determines the voltage polarity through the voltage polarity detection circuit of the DC input terminal, and performs corresponding operations or fault alarms. When connecting an energy storage battery cluster to the DC input port of an energy storage converter, there are two connection methods for the positive and negative terminals of the energy storage battery cluster and the DC input port of the energy storage converter. Connection method one: The positive and negative terminals of the energy storage battery cluster are connected one-to-one with the positive and negative terminals of the DC input port of the energy storage converter, that is, the positive terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter and the negative terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter. This connection method is called the positive connection method. Connection method two: The positive and negative terminals of the energy storage battery cluster are connected in reverse order with the DC input port of the energy storage converter, that is, the positive terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter and the negative terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter. This connection method is called the reverse connection method.

[0030] The circuit described above can accurately detect the voltage polarity at the DC input terminal of the energy storage converter.

[0031] In one embodiment of this application, the detection module includes a diode and an optocoupler.

[0032] The detection module adopts a modular design, using two identical module circuits combined in different ways to form two technical solutions. The modular circuit mainly consists of diodes and optocouplers as core components, utilizing the unidirectional conduction characteristics of diodes and light-emitting diodes, as well as the electrical isolation characteristics of optocouplers. The detection module has two feedback signals, which always maintain opposite voltage levels, resulting in strong anti-interference capabilities. The use of optocouplers, diodes, and resistors in the circuit reduces hardware costs.

[0033] In one embodiment of this application, the energy storage converter control board includes an FPGA module and an MCU module, wherein the MCU module is communicatively connected to the FPGA module.

[0034] The FPGA module is used to transmit the high-level state information of the feedback signal FB_U and the low-level state information of the feedback signal FB_D to the MCU module; the MCU module is used to determine the voltage polarity of the DC input terminal as positive based on the feedback signal FB_U being a high-level signal and the feedback signal FB_D being a low-level signal, wherein the state of the energy storage converter includes: cold standby, hot standby, or operation. Alternatively,

[0035] The FPGA module is further configured to transmit the low-level state information of the feedback signal FB_U and the high-level state information of the feedback signal FB_D to the MCU module; the MCU module is further configured to determine that the voltage polarity of the DC input terminal is negative based on the low-level signal of the feedback signal FB_U and the high-level signal of the feedback signal FB_D, and the energy storage converter reports a DC input port voltage polarity abnormality fault and enters a fault protection state, prohibiting the energy storage converter from performing any operation.

[0036] The reverse connection method is similar and will not be described in detail here.

[0037] In one embodiment of this application, when the positive terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter and the negative terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter, the energy storage converter control board is further configured to receive the high-level feedback signal FB_U and the low-level feedback signal FB_D output by the detection module.

[0038] The FPGA chip on the control board of the energy storage converter transmits the high-level status information of the feedback signal FB_U and the low-level status information of the feedback signal FB_D to the MCU on the control board. The MCU on the control board determines that the voltage polarity of the DC input terminal is positive based on the feedback signal FB_U being a high-level signal and the feedback signal FB_D being a low-level signal. The energy storage converter can then switch to cold standby, hot standby, or running state.

[0039] In one embodiment of this application, the MCU module is configured to determine that the voltage polarity of the DC input terminal is positive based on the feedback signal FB_U being a high-level signal and the feedback signal FB_D being a low-level signal.

[0040] In one embodiment of this application, when the positive terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter and the negative terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter, the energy storage converter control board is further configured to receive a high-level feedback signal FB_D and a low-level feedback signal FB_U output by the detection module.

[0041] The FPGA chip on the control board of the energy storage converter transmits the low-level status information of the feedback signal FB_U and the high-level status information of the feedback signal FB_D to the MCU on the control board. The MCU on the control board determines that the voltage polarity of the DC input terminal is negative based on the low-level signal of the feedback signal FB_U and the high-level signal of the feedback signal FB_D. The energy storage converter reports a fault of abnormal voltage polarity at the DC input port and enters a fault protection state, prohibiting the energy storage converter from performing any operation.

[0042] In one embodiment of this application, the feedback signals of the detection module always maintain opposite level states, with one feedback signal being at a high level and the other at a low level.

[0043] In one embodiment of this application, the detection module includes two detection module circuits with identical circuit structures, which are connected in series.

[0044] Using two identical detection modules (e.g.) Figure 2 and Figure 3 The detection modules 1, 2, 3, and 4 shown are connected in series to the DC input terminal of the energy storage converter to realize the voltage polarity detection function of the DC input terminal of the energy storage converter. In the two technical solutions of this circuit, the feedback signals of the two detection modules always maintain opposite level states, that is, one feedback signal is at a high level and the other is at a low level. The control board of the energy storage converter accurately determines the voltage polarity of the DC input terminal through the different combinations of feedback signals from the DC input terminal voltage polarity detection circuit.

[0045] In one embodiment of this application, when the energy storage battery cluster is connected to the DC input port of the energy storage converter, the positive and negative terminals of the energy storage battery cluster are respectively connected to the positive and negative terminals of the DC input port of the energy storage converter.

[0046] Energy storage converters and energy storage batteries are the core components of electrochemical energy storage systems. When the energy storage battery cluster is connected to the DC input port of the energy storage converter, the positive and negative terminals of the battery cluster must correspond to the positive and negative terminals of the DC input port of the energy storage converter; this is a fundamental requirement for the normal operation of the energy storage system. The energy storage converter must have a DC input port voltage polarity detection function to detect the voltage polarity of the DC input port when the energy storage battery cluster is connected to the energy storage converter. The control board of the energy storage converter will perform corresponding operations or fault alarms based on the voltage polarity feedback from the detection circuit. When the voltage polarity detection feedback status of the DC input port of the energy storage converter is positive, the energy storage converter can switch to cold standby, hot standby, or operating mode. When the voltage polarity detection feedback status of the DC input port of the energy storage converter is negative, the energy storage converter will report a DC input port voltage polarity abnormality fault and enter a fault protection state, prohibiting any operation of the energy storage converter.

[0047] In one embodiment of this application, when the voltage polarity detection feedback state of the DC input port of the energy storage converter is positive, the energy storage converter can switch to cold standby, hot standby, or operating state; when the voltage polarity detection feedback state of the DC input port of the energy storage converter is negative, the energy storage converter reports a DC input port voltage polarity abnormality fault and enters a fault protection state.

[0048] The energy storage converter reports an abnormal polarity fault at the DC input port and enters fault protection mode, prohibiting the energy storage converter from performing any operations.

[0049] like Figure 2 The diagram shows a schematic of a voltage polarity detection circuit at the DC input terminal of an energy storage converter. When the energy storage battery cluster is connected to the DC input port of the energy storage converter, the control board of the energy storage converter accurately determines the voltage polarity through the feedback status of the voltage polarity detection circuit at the DC input terminal, and performs corresponding operations or fault alarms.

[0050] When connecting an energy storage battery cluster to the DC input port of an energy storage converter, there are two connection methods for the positive and negative terminals of the energy storage battery cluster and the DC input port of the energy storage converter. Connection method one: The positive and negative terminals of the energy storage battery cluster are connected one-to-one with the positive and negative terminals of the DC input port of the energy storage converter, that is, the positive terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter and the negative terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter. This connection method is called the positive connection method. Connection method two: The positive and negative terminals of the energy storage battery cluster are connected in reverse order with the DC input port of the energy storage converter, that is, the positive terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter and the negative terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter. This connection method is called the reverse connection method.

[0051] When the energy storage battery cluster is connected to the DC input port of the energy storage converter in a positive connection mode, the working principle of the voltage polarity detection circuit at the DC input terminal of the energy storage converter is as follows:

[0052] like Figure 2 As shown, V DC-BUS This represents the voltage difference between the positive and negative terminals of the DC input. R1 represents the resistance value of the current-limiting resistor R1, and R2 represents the resistance value of the current-limiting resistor R2. (V) OC2-D This represents the voltage drop across the LED of optocoupler OC2.

[0053] Step 1-1: Diode D1 is forward-biased, and its forward voltage drop is V. D1 The LED of optocoupler OC1 is connected in anti-parallel with diode D1, and a -V voltage is applied to the LED of optocoupler OC1. D1 The negative voltage of the voltage is such that the LED of optocoupler OC1 is in reverse cutoff and does not emit light; the collector (C) of the phototransistor of optocoupler OC1 is connected in series with the pull-up resistor R3 to the power supply's V. CC When the emitter of the phototransistor of optocoupler OC1 is connected to the GND terminal of the power supply, the phototransistor of optocoupler OC1 is in the off state because the light-emitting diode of optocoupler OC1 does not emit light, and the feedback signal FB_U is in the high level state.

[0054] Step 1-2: Diode D2 is reverse cut off, and a -V voltage is applied to it. OC2-D The negative voltage; the A terminal of the LED of optocoupler OC2 is connected in series with diode D1 and current limiting circuit R1 to the DC-BUS+ terminal, the K terminal of the LED of optocoupler OC2 is connected in series with current limiting resistor R2 to the DC-BUS- terminal, and a positive voltage V is applied to the LED of optocoupler OC2. OC2-D The current flowing through the LED of optocoupler OC2 is It is in the light-emitting state; the collector (C) of the phototransistor in optocoupler OC2 is connected in series with the pull-up resistor R4 and then connected to the power supply V. CC When the emitter of the phototransistor of optocoupler OC2 is connected to the GND terminal of the power supply, the phototransistor of optocoupler OC2 is in the on state because the light-emitting diode of optocoupler OC2 emits light, and the feedback signal FB_D is in a low level state.

[0055] Steps 1-3: The FPGA chip on the control board of the energy storage converter transmits the high-level status information of the feedback signal FB_U and the low-level status information of the feedback signal FB_D to the MCU on the control board. The MCU on the control board determines that the voltage polarity of the DC input terminal is positive based on the feedback signal FB_U being a high-level signal and the feedback signal FB_D being a low-level signal. The energy storage converter can then be switched to cold standby, hot standby, or running state.

[0056] When the energy storage battery cluster is connected to the DC input port of the energy storage converter in reverse connection mode, the working principle of the voltage polarity detection circuit at the DC input terminal of the energy storage converter is as follows:

[0057] like Figure 2 As shown, V OC1-D This represents the voltage drop across the LED of optocoupler OC1.

[0058] Steps 1-4: Diode D2 is forward-biased, and its forward voltage drop is V. D2 The LED of optocoupler OC2 is connected in anti-parallel with diode D2, and a -V voltage is applied to the LED of optocoupler OC2. D2 The negative voltage of the voltage is such that the LED of optocoupler OC2 is in reverse cutoff and does not emit light; the collector (C) of the phototransistor of optocoupler OC2 is connected in series with the pull-up resistor R4 to the power supply's V. CC When the emitter of the phototransistor of optocoupler OC2 is connected to the GND terminal of the power supply, since the light-emitting diode of optocoupler OC2 does not emit light, the phototransistor of optocoupler OC2 is in the off state, and the feedback signal FB_D is in a high level state.

[0059] Steps 1-5: Diode D1 is reverse cut off, and a -V voltage is applied to it. OC1-D The negative voltage; the A terminal of the LED of optocoupler OC1 is connected in series with diode D2 and current limiting circuit R2 to the DC-BUS- terminal, and the K terminal of the LED of optocoupler OC1 is connected in series with current limiting resistor R1 to the DC-BUS+ terminal. A positive voltage V is applied to the LED of optocoupler OC1. OC1-D The current flowing through the LED of optocoupler OC1 is It is in the light-emitting state; the collector (C) of the phototransistor in optocoupler OC1 is connected in series with the pull-up resistor R3, which is connected to the power supply V. CC When the emitter of the phototransistor of optocoupler OC1 is connected to the GND terminal of the power supply, the phototransistor of optocoupler OC1 is in the on state because the light-emitting diode of optocoupler OC1 emits light, and the feedback signal FB_U is in the low level state.

[0060] Steps 1-6: The FPGA chip on the control board of the energy storage converter transmits the low-level status information of the feedback signal FB_U and the high-level status information of the feedback signal FB_D to the MCU on the control board. The MCU on the control board determines that the voltage polarity of the DC input terminal is negative based on the low-level signal of the feedback signal FB_U and the high-level signal of the feedback signal FB_D. The energy storage converter reports a DC input port voltage polarity abnormality fault and enters the fault protection state, prohibiting the energy storage converter from performing any operation.

[0061] like Figure 3As shown, a schematic diagram of the voltage polarity detection circuit at the DC input terminal of the second type of energy storage converter is given. When the energy storage battery cluster is connected to the DC input port of the energy storage converter, the control board of the energy storage converter accurately determines its voltage polarity through the feedback status of the voltage polarity detection circuit at the DC input terminal, and performs corresponding operations or fault alarms.

[0062] like Figure 3 As shown, V DC-BUS This represents the voltage difference between the positive and negative terminals of the DC input. R1 represents the resistance value of the current-limiting resistor R1, and R2 represents the resistance value of the current-limiting resistor R2. (V) OC1-D This represents the voltage drop across the LED of optocoupler OC1.

[0063] When the energy storage battery cluster is connected to the DC input port of the energy storage converter in a positive connection mode, the working principle of the voltage polarity detection circuit at the DC input terminal of the energy storage converter is as follows:

[0064] Step 2-1: Diode D1 is reverse cut off, and a -V voltage is applied to it. OC1-D The negative voltage; the A terminal of the LED of optocoupler OC1 is connected in series with the current limiting circuit R1 to the DC-BUS+ terminal, and the K terminal of the LED of optocoupler OC1 is connected in series with diode D2 and current limiting resistor R2 to the DC-BUS- terminal. A positive voltage V is applied to the LED of optocoupler OC1. OC1-D The current flowing through the LED of optocoupler OC1 is It is in the light-emitting state; the collector (C) of the phototransistor in optocoupler OC1 is connected in series with the pull-up resistor R3, which is connected to the power supply V. CC When the emitter of the phototransistor of optocoupler OC1 is connected to the GND terminal of the power supply, the phototransistor of optocoupler OC1 is in the on state because the light-emitting diode of optocoupler OC1 emits light, and the feedback signal FB_U is in the low level state.

[0065] Step 2-2: Diode D2 is forward-biased, and its forward voltage drop is V. D2 The LED of optocoupler OC2 is connected in anti-parallel with diode D2, and a -V voltage is applied to the LED of optocoupler OC2. D2 The negative voltage of the voltage is such that the LED of optocoupler OC2 is in reverse cutoff and does not emit light; the collector (C) of the phototransistor of optocoupler OC2 is connected in series with the pull-up resistor R4 to the power supply's V. CC When the emitter of the phototransistor of optocoupler OC2 is connected to the GND terminal of the power supply, the phototransistor of optocoupler OC2 is in the off state because the light-emitting diode of optocoupler OC2 does not emit light, and the feedback signal FB_D is in the high level state.

[0066] Steps 2-3: The FPGA chip on the control board of the energy storage converter transmits the low-level status information of the feedback signal FB_U and the high-level status information of the feedback signal FB_D to the MCU on the control board. The MCU on the control board determines that the voltage polarity of the DC input terminal is positive based on the low-level signal of the feedback signal FB_U and the high-level signal of the feedback signal FB_D. The energy storage converter can then be switched to cold standby, hot standby, or running state.

[0067] like Figure 3 As shown, V OC2-D This represents the voltage drop across the LED of optocoupler OC2.

[0068] When the energy storage battery cluster is connected to the DC input port of the energy storage converter in reverse connection mode, the working principle of the voltage polarity detection circuit at the DC input terminal of the energy storage converter is as follows:

[0069] Steps 2-4: Diode D2 is reverse cut off, and a -V voltage is applied to it. OC2-D The negative voltage; the A terminal of the LED of optocoupler OC2 is connected in series with the current limiting circuit R2 to the DC-BUS- terminal, and the K terminal of the LED of optocoupler OC2 is connected in series with the diode D1 and the current limiting resistor R1 to the DC-BUS+ terminal. A positive voltage V is applied to the LED of optocoupler OC2. OC2-D The current flowing through the LED of optocoupler OC2 is It is in the light-emitting state; the collector (C) of the phototransistor in optocoupler OC2 is connected in series with the pull-up resistor R4 and then connected to the power supply V. CC When the emitter of the phototransistor of optocoupler OC2 is connected to the GND terminal of the power supply, the phototransistor of optocoupler OC2 is in the on state because the light-emitting diode of optocoupler OC2 emits light, and the feedback signal FB_D is in a low level state.

[0070] Steps 2-5: Diode D1 is forward-biased, and its forward voltage drop is V. D1 The LED of optocoupler OC1 is connected in anti-parallel with diode D1, and a -V voltage is applied to the LED of optocoupler OC1. D1 The negative voltage of the voltage is such that the LED of optocoupler OC1 is in reverse cutoff and does not emit light; the collector (C) of the phototransistor of optocoupler OC1 is connected in series with the pull-up resistor R3 to the power supply's V. CC When the emitter of the phototransistor of optocoupler OC1 is connected to the GND terminal of the power supply, the phototransistor of optocoupler OC1 is in the off state because the light-emitting diode of optocoupler OC1 does not emit light, and the feedback signal FB_U is in the high level state.

[0071] Steps 2-6: The FPGA chip on the control board of the energy storage converter transmits the high-level status information of the feedback signal FB_U and the low-level status information of the feedback signal FB_D to the MCU on the control board. The MCU on the control board determines that the voltage polarity of the DC input terminal is negative based on the high-level signal of the feedback signal FB_U and the low-level signal of the feedback signal FB_D. The energy storage converter reports a DC input port voltage polarity abnormality fault and enters a fault protection state, prohibiting the energy storage converter from performing any operation.

[0072] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A voltage polarity detection circuit at the DC input terminal of an energy storage converter, wherein, The circuit includes: an energy storage converter control board and a detection module. The energy storage converter control board is electrically connected to one end of the detection module, and one end of the detection module is connected to the DC input terminal of the energy storage converter. The positive terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter. Alternatively, the positive terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter.

2. The circuit as described in claim 1, wherein, The detection module includes diodes and optocouplers.

3. The circuit as described in claim 1, wherein, The energy storage converter control board includes an FPGA module and an MCU module, and the MCU module is communicatively connected to the FPGA module.

4. The circuit as described in claim 3, wherein, When the positive terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter, the energy storage converter control board is also used for... The system receives the high-level feedback signal FB_U and the low-level feedback signal FB_D output by the detection module.

5. The circuit as described in claim 4, wherein, The MCU module is used to determine that the voltage polarity of the DC input terminal is positive based on the feedback signal FB_U being a high-level signal and the feedback signal FB_D being a low-level signal.

6. The circuit as claimed in claim 1, wherein, When the positive terminal of the energy storage battery cluster is connected to the negative terminal of the DC input port of the energy storage converter, and the negative terminal of the energy storage battery cluster is connected to the positive terminal of the DC input port of the energy storage converter, the energy storage converter control board is also used for... The receiver detects the high-level feedback signal FB_D and the low-level feedback signal FB_U output by the detection module.

7. The circuit as claimed in claim 1, wherein, The feedback signals of the detection module always maintain opposite level states, with one feedback signal being high and the other being low.

8. The circuit as claimed in claim 1, wherein, The detection module includes two detection module circuits with identical circuit structures, which are connected in series.

9. The circuit according to any one of claims 1 to 8, wherein, When the energy storage battery cluster is connected to the DC input port of the energy storage converter, the positive and negative terminals of the energy storage battery cluster are respectively connected to the positive and negative terminals of the DC input port of the energy storage converter.

10. The circuit according to any one of claims 1 to 8, wherein, When the voltage polarity detection feedback state of the DC input port of the energy storage converter is positive, the energy storage converter can switch to cold standby, hot standby or running state. When the voltage polarity detection feedback status of the DC input port of the energy storage converter is negative, the energy storage converter reports a DC input port voltage polarity abnormality fault and enters a fault protection state.

Images