Energy storage system and black start method thereof, electronic device, and storage medium

Abstract

The present application provides an energy storage system and a black start method thereof, an electronic device, and a storage medium. Among them, the battery module is connected to the power bus to power the inverter, the switch module includes a first switch unit and a second switch unit connected in parallel, both of which are used to control the on-off state of the circuit between the battery module and the power bus, the switch control circuit includes a voltage acquisition unit and a switch control unit, the voltage acquisition unit is used to collect the voltage of the switch module, and the switch control unit can drive the switch control unit when the voltage at both ends of the second switch unit is less than the first threshold value, and turn on the second switch unit, so that the inverter can be stably powered by the battery module in an off-grid state, without the need to set up additional power supplies and switch devices, and has the advantages of low cost and simple operation.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage systems, and in particular to an energy storage system and a black start method thereof, an electronic device, and a storage medium. Background Art

[0002] Household energy storage systems usually consist of battery packs, BMS (battery management system), PCS (energy storage inverter), photovoltaic panels or AC mains power. PCS can start working through photovoltaic or mains power supply and send instructions to BMS. BMS controls the battery main circuit relay or contactor to close, thereby realizing photovoltaic or mains power charging of batteries and battery discharge to household loads.

[0003] In an off-grid state with no photovoltaic power or mains electricity, the PCS has no power supply and cannot start working, so it is impossible to use the battery to power household loads. At this time, a black start operation is required to allow the BMS to control the battery main circuit relay or contactor to close, and the battery voltage output is used to power the PCS, so that the entire energy storage system can start working normally. However, when the existing PCS performs the black start process, the software is usually in the BOOT state, and the relay or contactor of the circuit cannot be operated, resulting in the need for additional signal latching, or the need to continuously press the black start button, which seriously affects the efficiency and stability of the black start operation for grid recovery.

[0004] Therefore, how to provide an energy storage system and its black start method, electronic equipment, and storage medium to improve the operational efficiency and stability of black start operation for grid recovery has become one of the technical problems that people in this field urgently need to solve. Summary of the invention

[0005] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0006] To this end, the first purpose of the present application is to propose an energy storage system and a black start method, an electronic device, and a storage medium thereof, which can improve the operational efficiency and stability of the black start operation for grid recovery.

[0007] To achieve the above-mentioned purpose, the first embodiment of the present application proposes an energy storage system, including an inverter and a power bus that are electrically connected, and:

[0008] A battery module connected to the power bus;

[0009] A switch module is arranged between the battery module and the power bus; the switch module comprises a first switch unit and a second switch unit connected in parallel;

[0010] A switch control circuit is arranged between the battery module and the power bus, and the switch control circuit includes a voltage acquisition unit and a switch control unit; wherein,

[0011] The input end of the voltage acquisition unit is respectively connected to the input end and the output end of the switch module; the output end of the voltage acquisition unit is connected to the switch control unit, and the output end of the switch control unit is connected to the control end of the second switch unit; the voltage acquisition unit outputs a first control signal when the first switch unit is turned on and the voltage across the second switch unit is less than a first threshold, and the switch control unit drives the second switch unit to turn on based on the first control signal.

[0012] Optionally, the energy storage system also includes an auxiliary source circuit and a control module. The auxiliary source circuit is arranged between the power bus and the control module, and is used to convert the electric energy on the power bus into low-voltage electric energy required to activate the control module, so that the control module can output a second control signal to replace the control authority of the first control signal over the switch control unit, so that the switch control unit can drive the second switch unit to conduct based on the second control signal.

[0013] Optionally, the voltage acquisition unit includes a differential amplifier, a comparator, a first power supply and a second power supply; wherein,

[0014] The two input terminals of the differential amplifier are respectively connected to the input terminal and the output terminal of the second switch unit, and are used to obtain the voltage across the second switch unit when the first switch unit is turned on, and output the voltage value to the comparator;

[0015] The two input terminals of the comparator are respectively connected to the output terminal of the differential amplifier and the first power supply, and the output terminal of the comparator is respectively connected to the second power supply and the switch control unit.

[0016] Optionally, the switch control unit includes at least a first switch tube; a first end of the first switch tube is connected to the control end of the second switch unit, a second end of the first switch tube is grounded, and a third end of the first switch tube is connected to the second power supply and the output end of the comparator;

[0017] When the voltage across the second switch unit is less than the first threshold, the comparator outputs the first control signal of a high level, the first switch tube is turned on, and drives the second switch unit to automatically perform a closing action and turn on;

[0018] When the voltage across the second switch unit is greater than the first threshold, the comparator outputs the first control signal of a low level, the first switch tube is turned off, and the second switch unit is driven not to perform a closing action and remain turned off.

[0019] Optionally, the switch control unit includes a second switch tube, a third switch tube, a third power supply and a fourth power supply; wherein,

[0020] The third power supply is respectively connected to the first end of the second switch tube, the first end of the third switch tube, and the third end of the first switch tube, the fourth power supply is respectively connected to the third end of the second switch tube, the third end of the third switch tube, and the output end of the control module, and the second ends of the second switch tube and the third switch tube are both grounded;

[0021] When the control module outputs the second control signal of a high level, the second switch tube and the third switch tube are turned on, the first switch tube is turned off, and the second switch unit is driven not to perform a closing action and is turned off;

[0022] When the control module outputs the second control signal of a low level, the second switch tube and the third switch tube are turned off, the first switch tube is turned on, and drives the second switch unit to perform a closing action and turn on.

[0023] Optionally, the switch control unit further includes a first diode, a second diode, a third diode and a fourth diode; wherein,

[0024] The anode of the first diode is connected to the second power supply and the output end of the comparator respectively, and the cathode of the first diode is connected to the third end of the first switch tube and the first end of the second switch tube respectively;

[0025] The anode of the second diode is connected to the third power supply and the first end of the third switch tube respectively, and the cathode of the second diode is connected to the third end of the first switch tube and the first end of the second switch tube respectively;

[0026] The anode of the third diode is connected to the fourth power supply and the third end of the third switch tube respectively, and the cathode of the third diode is connected to the output end of the control module respectively;

[0027] The anode of the fourth diode is connected to the cathode of the third diode and the output end of the control module respectively, and the cathode of the fourth diode is connected to the third end of the second switch tube.

[0028] Optionally, the control module includes at least a battery management system, a central controller and / or a microcontroller; wherein the central controller or microcontroller is used to output the second control signal, and the battery management system is used to power the first power supply, the second power supply, the third power supply, and the fourth power supply.

[0029] To achieve the above-mentioned purpose, the second aspect of the present application proposes a black start method for an energy storage system, wherein the energy storage system includes a battery module, a power bus, an inverter, a first switch unit and a second switch unit that electrically connect the battery module to the power bus and are arranged in parallel, a voltage acquisition unit and a switch control unit that are electrically connected to the second switch unit, an auxiliary source circuit connected to the power bus, and a control module that respectively connects the auxiliary source circuit to the switch control unit; the black start method includes the following steps:

[0030] Controlling the first switch unit to perform a switch closing action so that the battery module supplies power to the power bus through the first switch unit;

[0031] The voltage acquisition unit is used to acquire the voltage between the input terminal and the output terminal of the second switch unit, and a first control signal is output based on the voltage value, so that the switch control unit drives the second switch unit to perform a closing action and turn on;

[0032] The auxiliary source circuit is used to convert the electric energy of the power bus into the low-voltage electric energy required by the control module, and the control module is activated, so that the control module can output a second control signal based on an external input instruction to replace the control authority of the first control signal over the switch control unit, so that the switch control unit drives the second switch unit to perform a closing action and turn on.

[0033] Optionally, the control module needs to be activated after the first switch unit performs a switch closing action and continues for a preset time.

[0034] Optionally, the voltage acquisition unit includes a differential amplifier and a comparator, and the switch control unit includes a first switch tube; the switch control unit drives the second switch unit to perform a closing action and conduction based on the first control signal, comprising:

[0035] Connecting two input terminals of the differential amplifier to the input terminal and the output terminal of the second switch unit respectively, so as to obtain a voltage difference between the two terminals of the second switch unit when the first switch unit is turned on, and output the voltage value to the comparator;

[0036] The comparator is used to compare the received voltage value with a preset first threshold value, and when the voltage value is less than the first threshold value, the first control signal of a high level is output to the first switch tube, so that the first switch tube is turned on, and the second switch unit is driven to automatically perform a closing action and turn on.

[0037] Optionally, the switch control unit further includes a second switch tube and a third switch tube, and the control module is electrically connected to the third end of the second switch tube and the third end of the third switch tube respectively;

[0038] When the control module outputs the second control signal of a high level, the second switch tube and the third switch tube are turned on, the first switch tube is turned off, and the second switch unit is driven not to perform a closing action and is turned off;

[0039] When the control module outputs the second control signal of a low level, the second switch tube and the third switch tube are turned off, the first switch tube is turned on, and drives the second switch unit to perform a closing action and turn on.

[0040] To achieve the above-mentioned purpose, the third aspect of the present application provides an electronic device, characterized in that it includes:

[0041] Memory for storing computer programs;

[0042] A processor is used to execute the computer program to implement the black start method of the energy storage system described in any one of the above embodiments.

[0043] To achieve the above-mentioned purpose, the fourth aspect of the present application proposes a computer-readable storage medium on which a computer program is stored, characterized in that when the computer program is executed by a processor, a black start method for an energy storage system as described in any of the above-mentioned embodiments is implemented.

[0044] The energy storage system and black start method thereof, electronic device, and storage medium provided by the present application have at least the following beneficial effects:

[0045] The present application provides an energy storage system and a black start method thereof, an electronic device, and a storage medium. Among them, the battery module is connected to the power bus to power the inverter, the switch module includes a first switch unit and a second switch unit connected in parallel, both of which are used to control the on-off state of the circuit between the battery module and the power bus, the switch control circuit includes a voltage acquisition unit and a switch control unit, the voltage acquisition unit is used to collect the voltage of the switch module, and the switch control unit can drive the switch control unit when the voltage at both ends of the second switch unit is less than the first threshold value, and turn on the second switch unit, so that the inverter can be stably powered by the battery module in an off-grid state, without the need to set up additional power supplies and switch devices, and has the advantages of low cost and simple operation.

[0046] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0048] Figure 1 The present invention is a schematic structural diagram of an energy storage system according to an embodiment of the present application.

[0049] Figure 2 The present invention is a schematic diagram showing a circuit structure of an energy storage system according to an embodiment of the present application.

[0050] Figure 3 The present invention is a flow chart showing a black start method of an energy storage system according to an embodiment of the present application.

[0051] Figure 4 The present invention is a schematic diagram showing the structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0052] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0053] According to a first aspect of the present application, there is provided an energy storage system, such as Figure 1 and Figure 2As shown, the system includes a battery module, a power bus, an inverter, and a switch module and a switch control circuit arranged between the battery module and the power bus. The battery module is connected to the power bus to supply power to the inverter, the switch module includes a first switch unit and a second switch unit connected in parallel, both of which are used to control the on-off state of the circuit between the battery module and the power bus, the switch control circuit includes a voltage acquisition unit and a switch control unit, the voltage acquisition unit is used to acquire the voltage of the first switch unit and / or the second switch unit, and the switch control unit can control the on-off state of the second switch unit based on the voltage acquired by the voltage acquisition unit.

[0054] As an energy storage device of the energy storage system, the battery module can achieve good energy storage and load power supply effects. The battery module can at least include multiple battery modules connected in series or in parallel. Taking lithium iron phosphate batteries as an example, the output operating voltage of each battery cell is usually around 2.5V~3.65V, so multiple battery cells need to be connected in series to increase the total output voltage. At the same time, battery cells can also be connected in parallel to increase the total output current and improve the power output of the battery assembly.

[0055] In a normal energy storage scenario of an energy storage system, the battery module is electrically connected to the DC connection end of the inverter through a power bus, and the AC connection end of the inverter is electrically connected to the AC grid and / or the load through a transformer, so that the inverter can convert the DC power in the battery module into AC power and output it to the AC grid or power the load, and can also convert the AC power provided by the AC grid into DC power to charge the battery module for energy storage.

[0056] Alternatively, the inverter may specifically be a power conversion system (PCS), the AC connection end of which is directly electrically connected to the AC grid and / or the load. The energy storage system may provide DC power to the PCS, which then converts the DC power provided by the energy storage system into AC power and outputs it to the AC grid or supplies power to the load, or it may draw power from the AC grid to charge the battery modules in the energy storage system.

[0057] In the above application scenarios, if the inverter cannot be powered from other power sources such as the AC grid to start, the battery module in the energy storage system needs to power the inverter so that the inverter can start normally. This process can be called a black start. However, when the existing inverter performs the black start process, the software is usually in the BOOT state (this state usually lasts for 10s to 60s), and the relays or contactors in the loop of the energy storage system cannot be operated, resulting in the need for additional signal latching, or the need to continuously press the black start button, which seriously affects the efficiency and stability of the black start operation for grid recovery.

[0058] The present application sets a first switch unit and a second switch unit connected in parallel between the battery module and the power bus, wherein the first switch unit is a black start switch, including a current limiting resistor R1 and a black start button S1 connected in series, and the second switch unit is a contactor or a relay, including a control coil and a switch S2. During the black start process, first, the battery module and the power bus are quickly turned on by manually controlling the black start button S1 to close, so that the electric energy can be sequentially supplied to the inverter through the current limiting resistor R1, the black start button S1 and the power bus. Then, by connecting the input end of the voltage acquisition unit to the input end and the output end of the first switch unit and / or the second switch unit respectively, and connecting the output end of the voltage acquisition unit to the switch control unit, the voltage acquisition unit can obtain the voltage at both ends of the second switch unit in real time during the black start process, and output a first control signal based on the magnitude of the voltage value. Finally, the switch control unit is connected to the control end of the second switch unit, that is, the control coil, so that the switch control unit can drive the control coil of the second switch unit to energize based on the first control signal, so that the switch S2 of the second switch unit performs a closing action and turns on.

[0059] Specifically, when the first switch unit is turned on and the voltage value across the second switch unit is less than the first threshold, the inverter can obtain enough electric energy from the power bus to start, the voltage acquisition unit will output a first control signal, and the switch control unit drives the switch S2 of the second switch unit to perform a closing action and turn on based on the first control signal, so that the battery module can stably supply power to the inverter connected to the power bus. In other words, the energy storage system provided in the present application can provide direct current to the inverter through the battery module when the inverter is off-grid, and the inverter then converts the direct current provided by the energy storage system into alternating current and outputs it to the AC power grid or load, thereby realizing rapid power recovery and ensuring a stable power transmission effect.

[0060] The energy storage system provided by the present application only needs to connect the voltage acquisition unit to the two ends of the second switch unit respectively, and when the inverter starts to start, the second switch unit can be automatically controlled to be turned on according to the voltage at both ends of the second switch unit, so that the battery module can stably supply power to the inverter without setting up additional power supplies and switching devices, which has the advantages of low cost and simple operation. In addition, this process does not require additional processing of the original software BOOT program of the energy storage system, does not affect the platform nature of the software, and makes the energy storage system also have the advantage of a wide range of adaptability.

[0061] In some embodiments, the energy storage system further includes an auxiliary source circuit and a control module. The auxiliary source circuit is disposed between the power bus and the control module. The auxiliary source circuit is used to convert the electrical energy on the power bus into low-voltage electrical energy for activating the control module.

[0062] While the battery module supplies power to the inverter electrically connected to the power bus through the first switch unit, it can also supply power to the control module through the auxiliary source circuit electrically connected to the power bus, thereby activating the control module so that the control module can be driven by an external input instruction and output a second control signal. The second control signal can replace the control authority of the first control signal over the switch control unit, thereby enabling the switch control unit to energize the control coil of the second switch unit under the drive of the second control signal, so that the switch S2 of the second switch unit performs a closing action and turns on.

[0063] Specifically, the control module includes at least a controller and a battery management system (BMS), and the controller may include but is not limited to a chip or device with logic control capability such as a CPU and an MCU. Among them, the BMS can not only provide the low-voltage power required for activation (restart) to the controller, but also provide low-voltage power to other switch devices or operational amplifier devices in the switch control circuit, such as the subsequent first power supply VDD1, the second power supply VDD2, the third power supply VDD3, and the fourth power supply VDD4. The supply voltages of the first power supply VDD1, the second power supply VDD2, the third power supply VDD3, and the fourth power supply VDD4 can be the same or different, and are not specifically limited here.

[0064] In some embodiments, the voltage acquisition unit at least includes a differential amplifier U1 and a comparator U2. The two input terminals of the differential amplifier U1 are respectively connected to the input terminal and the output terminal of the second switch unit, the two input terminals of the comparator U2 are respectively connected to the output terminal of the differential amplifier U1 and the first power supply VDD1, and the output terminal of the comparator U2 is connected to the switch control unit.

[0065] By connecting the two input terminals of the differential amplifier U1 to the input terminal and the output terminal of the second switch unit respectively, when the first switch unit is turned on, the differential amplifier U1 can timely obtain the voltage across the second switch unit and input the acquired voltage value to the comparator U2.

[0066] By connecting the two input terminals of the comparator U2 to the output terminal of the differential amplifier U1 and the first power supply VDD1 respectively, the comparator U2 can output the first control signal according to the magnitude relationship between the input voltage of the first power supply VDD1 and the input voltage of the differential amplifier U1.

[0067] Therefore, the voltage acquisition unit can control the conduction of the switch control unit through the first control signal, thereby lowering the voltage signal between the coil control end of the second switch unit and the switch control unit, energizing and conducting the circuit where the control coil of the second switch unit is located, so that the switch S2 of the second switch unit performs a closing action and turns on; or, the voltage acquisition unit controls the shutdown of the switch control unit through the first control signal, thereby raising the voltage signal between the control coil of the second switch unit and the switch control unit, shutting off the circuit where the control coil of the second switch unit is located, and keeping the switch S2 of the second switch unit turned off.

[0068] It should be noted that the differential amplifier U1 is used to collect the voltage at both ends of the second switch unit when the energy storage system is not configured with battery module voltage sampling and power bus voltage sampling, and in order to simplify the illustrated structure and facilitate description, Figure 2 The two input terminals of the differential amplifier U1 shown in the figure are directly connected to the input terminal and the output terminal of the second switch unit respectively. In actual application, the two terminals of the differential amplifier U1 need to be connected to the input terminal and the output terminal of the second switch unit through at least one or more voltage-dividing resistors or other voltage-dividing devices to ensure normal sampling of the differential amplifier U1.

[0069] Further, Figure 2 The device U2 in can also be a subtractor U2. The energy storage system is usually configured with battery module voltage sampling and power bus voltage sampling. By connecting the two input ends of the subtractor U2 to the output end of the battery module voltage sampling and the output end of the power bus voltage sampling respectively, the subtractor can subtract the voltage output by the power bus from the voltage output by the battery module, and output the voltage difference to the comparator, so that the comparator U2 can output the first control signal according to the magnitude relationship between the voltage of the input of the first power supply VDD1 and the voltage difference of the input of the subtractor U1.

[0070] In some embodiments, the switch control unit includes at least one first switch tube Q1, and the first end of the first switch tube Q1 is connected to the control end of the second switch unit, the second end of the first switch tube Q1 is grounded, and the third end of the first switch tube Q1 is connected to the second power supply VDD2 and the output end of the comparator U2.

[0071] As an example, the first switch tube Q1 is an NPN transistor, the first end of the first switch tube Q1 is the collector of the transistor, the second end of the first switch tube Q1 is the emitter of the transistor, and the third end of the first switch tube Q1 is the base of the transistor. The first power supply VDD1 is grounded through the pull-up resistor R2 and the pull-down resistor R3. At the same time, the in-phase input end of the comparator U2 is connected to the first power supply VDD1 through the pull-up resistor R2, and the inverting input end of the comparator U2 is connected to the output end of the differential amplifier U1. At this time, the voltage value input to the comparator U2 between the pull-up resistor R2 and the pull-down resistor R3 can be used as the first threshold value for comparing the magnitude relationship with the voltage value input to the differential amplifier U1.

[0072] Therefore, when the voltage across the second switch unit is less than the first threshold, the comparator U2 outputs a high-level first control signal, so that the second power supply VDD2 can pull up the voltage signal at the third end of the first switch tube Q1 through the pull-up resistor R4, and the first switch tube Q1 will be turned on, thereby causing the control coil of the second switch unit to be energized and turned on, and driving the switch S2 of the second switch unit to perform a closing action and turn on.

[0073] On the contrary, when the voltage across the second switch unit is greater than the first threshold, the comparator U2 outputs a low-level first control signal, so that the second power supply VDD2 cannot pull up the voltage signal at the first end of the first switch tube Q1 through the pull-up resistor R4, and the first switch tube Q1 will remain turned off, which means that the control coil of the second switch unit is not conducting, and the switch S2 of the second switch unit does not perform a closing action and remains turned off.

[0074] In some embodiments, the switch control unit may further include a second switch tube Q2 and a third switch tube Q3. The first end of the second switch tube Q2 is respectively connected to the first end of the third switch tube Q3 and the third end of the first opening tube, the second end of the second switch tube Q2 and the second end of the third switch tube Q3 are grounded, the third end of the second switch tube Q2 and the third end of the third switch tube Q3 are connected to each other, and are commonly connected to the output end of the control module, where the control module refers to a controller disposed in the control module.

[0075] Further, the switch control unit may also include a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4. Among them, the anode of the first diode D1 is connected to the second power supply VDD2 and the output end of the comparator U2 respectively, and the cathode of the first diode D1 is connected to the third end of the first switch tube Q1 and the first end of the second switch tube Q2 respectively; the anode of the second diode D2 is connected to the third power supply VDD3 and the first end of the third switch tube Q3 respectively, and the cathode of the second diode D2 is connected to the third end of the first switch tube Q1 and the first end of the second switch tube Q2 respectively; the anode of the third diode D3 is connected to the fourth power supply VDD4 and the third end of the third switch tube Q3 respectively, the cathode of the third diode D3 is connected to the output end of the controller and the anode of the fourth diode D4 respectively, and the cathode of the fourth diode D4 is connected to the third end of the second switch tube Q2.

[0076] As an example, the second switch tube Q2 and the third switch tube Q3 are both NPN transistors, the controller in the control module is a CPU, the third power supply VDD3 is respectively connected to the first end of the third switch tube Q3, the first end of the second switch tube Q2, and the third end of the first switch tube Q1 through a pull-up resistor R5, the fourth power supply VDD4 is respectively connected to the third end of the third switch tube Q3 and the third end of the second switch tube Q2 through a pull-up resistor R6, and the third end of the third switch tube Q3 is also grounded through a pull-down resistor R7.

[0077] Therefore, when the energy storage system software is in the BOOT program, the CPU will not be driven by external instructions and will show a high-impedance state. At this time, the fourth power supply VDD4 pulls up the voltage signal of the third end of the third switch tube Q3 through the pull-up resistor R6, so that the third switch tube Q3 is turned on. The third end of the second switch tube Q2 is grounded due to the pull-down resistor R7, so that the second switch tube Q2 remains turned off, so that the voltage signal of the third end of the first switch tube Q1 will not be affected by the second switch tube Q2 and the third switch tube Q3. In other words, at this time, the on-off state of the first switch tube Q1 is completely controlled by the first control signal output by the comparator U2.

[0078] Specifically, when the comparator U2 outputs a low-level first control signal, the first switch tube Q1 will remain off, and the switch S2 of the second switch unit will not perform a closing action and remain off. When the comparator U2 outputs a high-level first control signal, the first switch tube Q1 will be turned on, and drive the switch S2 of the second switch unit to perform a closing action and turn on.

[0079] When the energy storage system completes the software BOOT program (usually 10s~60s), the CPU can be driven by external instructions to output a high or low level second control signal. At this time, the on-off state of the second switch tube Q2 and the third switch tube Q3 will be synchronously driven by the second control signal, so that the on-off state of the first switch tube Q1 will be jointly affected by the second switch tube Q2 and the third switch tube Q3, and replace the first control signal's authority control over the on-off state of the first switch tube Q1. In other words, at this time, the second control signal output by the CPU will replace the first control signal output by the comparator U2's authority control over the on-off state of the first switch tube Q1.

[0080] Specifically, when the CPU outputs a low-level second control signal, the voltage signals at the third end of the second switch tube Q2 and the third end of the third switch tube Q3 are pulled low, the second switch tube Q2 and the third switch tube Q3 will be turned off, and the second power supply VDD2 will pull up the voltage signal at the third end of the first switch tube Q1 through the pull-up resistor R5 and the second diode, turn on the first switch tube Q1, and drive the switch S2 of the second switch unit to perform a closing action and turn on. When the CPU outputs a high-level second control signal, the voltage signals at the third end of the second switch tube Q2 and the third end of the third switch tube Q3 are pulled high, the second switch tube Q2 and the third switch tube Q3 will be turned on, so that the voltage signal at the third end of the first switch tube Q1 is pulled low, the first switch tube Q1 will be turned off, and drive the switch S2 of the second switch unit not to perform a closing action and turn off.

[0081] As a result, the inverter can switch safely, stably and smoothly from off-grid state to grid-connected state.

[0082] It should be noted that the use of NPN transistors as the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 is only an example. In the actual application of the energy storage system, the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 include but are not limited to any one of switching devices such as a transistor, an insulated gate bipolar transistor (IGBT), or a metal oxide semiconductor field effect transistor (MOSFET).

[0083] According to a second aspect of the present application, a black start method for an energy storage system is provided, such as Figure 2 and Figure 3 As shown, the method includes using the energy storage device described in any of the above embodiments, and includes the following steps:

[0084] First, step S1 is executed to control the first switch unit to execute a switch closing action, so that the battery module supplies power to the power bus through the first switch unit.

[0085] Then, step S2 is executed to obtain the voltage between the input and output ends of the second switch unit using the voltage acquisition unit, and output a first control signal based on the acquired voltage value, so that the switch control unit drives the second switch unit to perform a closing action and turn on.

[0086] Finally, execute step S3, use the auxiliary source circuit to convert the electric energy of the power bus into the low-voltage electric energy required by the control module, activate the control module, and enable the control module to output a second control signal based on an external input instruction to replace the control authority of the first control signal over the switch control unit, so that the switch control unit drives the second switch unit to perform a closing action and turn on.

[0087] The control module needs to execute a switch closing action on the first switch unit and complete the activation after a preset time.

[0088] It should be noted that for details not disclosed in the black start method of the energy storage system provided in this embodiment, please refer to the details disclosed in the energy storage system of the embodiment of the present application, and no further details will be given here.

[0089] According to a third aspect of the present application, an electronic device is provided, such as Figure 4 As shown, the electronic device may include: a transceiver, a processor, and a memory. The electronic device may be the controller in any of the above embodiments.

[0090] The processor executes the computer execution instructions stored in the memory, so that the processor executes the scheme in the above embodiment. The processor can be a general-purpose processor, including a central processing unit CPU, a network processor (NP), etc.; it can also be a digital signal processor DSP, an application-specific integrated circuit ASIC, a field programmable gate array FPGA or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components.

[0091] The memory is connected to the processor through a system bus and completes communication with each other. The memory is used to store computer program instructions.

[0092] The transceiver can perform receiving load data and sending power supply control signals.

[0093] The electronic device may further include a communication interface to communicate and interact with an external or internal device through the communication interface. The external device may be, for example, a client (eg, a mobile phone, a tablet).

[0094] The system bus can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus. The system bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 The term "bus" is represented by only one thick line, but it does not mean that there is only one bus or one type of bus. Transceivers are used to implement communication between the database access device and other computers (such as clients, read-write libraries, and read-only libraries). Memory may include random access memory (RAM) and may also include non-volatile memory.

[0095] According to the fourth aspect of the present application, a computer-readable storage medium is also provided, on which a computer program is stored. When the computer program is executed by a processor, the technical solution of the above-mentioned black start method embodiment is implemented. The implementation principle and technical effect are similar and will not be repeated here.

[0096] Computer-readable media may include random access memory (RAM), read-only memory (ROM), compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium designed to carry or store the desired program code in the form of instructions or data structures and can be accessed by the computer. Also, any connection is properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwave are included in the definition of medium. Disk and disc as used herein include optical disc, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks usually reproduce data magnetically, while optical discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0097] In summary, the present application provides an energy storage system and its black start method, electronic device, and storage medium. Among them, the battery module is connected to the power bus to power the inverter, the switch module includes a first switch unit and a second switch unit connected in parallel, both of which are used to control the on-off state of the circuit between the battery module and the power bus, the switch control circuit includes a voltage acquisition unit and a switch control unit, the voltage acquisition unit is used to collect the voltage of the switch module, and the switch control unit can drive the switch control unit when the voltage at both ends of the second switch unit is less than the first threshold value, and turn on the second switch unit, so that the inverter can stably supply power to the inverter through the battery module in an off-grid state, without the need to set up additional power supplies and switching devices, and has the advantages of low cost and simple operation.

[0098] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they contradict each other.

[0099] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. An energy storage system, comprising an inverter and a power busbar electrically connected, characterized in that: The energy storage system comprises: A battery module connected to the power bus; A switch module is arranged between the battery module and the power bus; the switch module comprises a first switch unit and a second switch unit connected in parallel; A switch control circuit is arranged between the battery module and the power bus, and the switch control circuit includes a voltage acquisition unit and a switch control unit; wherein, The input end of the voltage acquisition unit is respectively connected to the input end and the output end of the switch module; the output end of the voltage acquisition unit is connected to the switch control unit, and the output end of the switch control unit is connected to the control end of the second switch unit; the voltage acquisition unit outputs a first control signal when the first switch unit is turned on and the voltage across the second switch unit is less than a first threshold, and the switch control unit drives the second switch unit to turn on based on the first control signal; The voltage acquisition unit includes a comparator and a second power supply; the switch control unit includes at least a first switch tube; a first end of the first switch tube is connected to a control end of the second switch unit, a second end of the first switch tube is grounded, and a third end of the first switch tube is connected to the second power supply and an output end of the comparator; When the voltage across the second switch unit is less than the first threshold, the comparator outputs the first control signal of a high level, the first switch tube is turned on, and drives the second switch unit to automatically perform a closing action and turn on; When the voltage across the second switch unit is greater than the first threshold, the comparator outputs the first control signal of a low level, the first switch tube is turned off, and the second switch unit is driven not to perform a closing action and remain turned off.

2. The energy storage system according to claim 1, characterized in that: The energy storage system also includes an auxiliary source circuit and a control module. The auxiliary source circuit is arranged between the power bus and the control module, and is used to convert the electric energy on the power bus into the low-voltage electric energy required to activate the control module, so that the control module can output a second control signal to replace the control authority of the first control signal over the switch control unit, so that the switch control unit can drive the second switch unit to conduct based on the second control signal.

3. The energy storage system according to claim 2, characterized in that: The voltage acquisition unit also includes a differential amplifier and a first power supply; wherein, The two input terminals of the differential amplifier are respectively connected to the input terminal and the output terminal of the second switch unit, and are used to obtain the voltage across the second switch unit when the first switch unit is turned on, and output the voltage value to the comparator; The two input terminals of the comparator are respectively connected to the output terminal of the differential amplifier and the first power supply, and the output terminal of the comparator is respectively connected to the second power supply and the switch control unit.

4. The energy storage system according to claim 3, characterized in that: The switch control unit includes a second switch tube, a third switch tube, a third power supply and a fourth power supply; wherein, The third power supply is respectively connected to the first end of the second switch tube, the first end of the third switch tube, and the third end of the first switch tube, the fourth power supply is respectively connected to the third end of the second switch tube, the third end of the third switch tube, and the output end of the control module, and the second ends of the second switch tube and the third switch tube are both grounded; When the control module outputs the second control signal of a high level, the second switch tube and the third switch tube are turned on, the first switch tube is turned off, and the second switch unit is driven not to perform a closing action and is turned off; When the control module outputs the second control signal of a low level, the second switch tube and the third switch tube are turned off, the first switch tube is turned on, and drives the second switch unit to perform a closing action and turn on.

5. The energy storage system according to claim 4, characterized in that: The switch control unit further includes a first diode, a second diode, a third diode and a fourth diode; wherein, The anode of the first diode is connected to the second power supply and the output end of the comparator respectively, and the cathode of the first diode is connected to the third end of the first switch tube and the first end of the second switch tube respectively; The anode of the second diode is connected to the third power supply and the first end of the third switch tube respectively, and the cathode of the second diode is connected to the third end of the first switch tube and the first end of the second switch tube respectively; The anode of the third diode is connected to the fourth power supply and the third end of the third switch tube respectively, and the cathode of the third diode is connected to the output end of the control module respectively; The anode of the fourth diode is connected to the cathode of the third diode and the output end of the control module respectively, and the cathode of the fourth diode is connected to the third end of the second switch tube.

6. The energy storage system according to claim 4, characterized in that: The control module includes at least a battery management system, a central controller and / or a microcontroller; wherein the central controller or the microcontroller is used to output the second control signal, and the battery management system is used to supply power to the first power supply, the second power supply, the third power supply, and the fourth power supply.

7. A black start method for an energy storage system, characterized in that: The energy storage system includes a battery module, a power bus, an inverter, a first switch unit and a second switch unit electrically connecting the battery module to the power bus and arranged in parallel, a voltage acquisition unit and a switch control unit electrically connected to the second switch unit, an auxiliary source circuit connected to the power bus, and a control module respectively connecting the auxiliary source circuit to the switch control unit; the voltage acquisition unit includes a differential amplifier and a comparator, and the switch control unit includes a first switch tube; the black start method includes the following steps: Controlling the first switch unit to perform a switch closing action so that the battery module supplies power to the power bus through the first switch unit; The voltage acquisition unit is used to acquire the voltage between the input terminal and the output terminal of the second switch unit, and a first control signal is output based on the voltage value, so that the switch control unit drives the second switch unit to perform a closing action and turn on; The auxiliary source circuit is used to convert the electric energy of the power bus into the low-voltage electric energy required by the control module, and the control module is activated, so that the control module can output a second control signal based on an external input instruction to replace the control authority of the first control signal over the switch control unit, so that the switch control unit drives the second switch unit to perform a closing action and turn on; Outputting a first control signal based on the voltage value so that the switch control unit drives the second switch unit to perform a closing action and conduct, includes: Connecting two input terminals of the differential amplifier to the input terminal and the output terminal of the second switch unit respectively, so as to obtain a voltage difference between the two terminals of the second switch unit when the first switch unit is turned on, and output the voltage value to the comparator; The comparator is used to compare the received voltage value with a preset first threshold value. When the voltage value is less than the first threshold value, the first control signal of a high level is output to the first switch tube, so that the first switch tube is turned on, and the second switch unit is driven to automatically perform a closing action and turn on.

8. The black start method according to claim 7, characterized in that: The control module needs to be activated after the first switch unit performs a switch closing action and continues for a preset time.

9. The black start method according to claim 8, characterized in that: The switch control unit further includes a second switch tube and a third switch tube, and the control module is electrically connected to the third end of the second switch tube and the third end of the third switch tube respectively; When the control module outputs the second control signal of a high level, the second switch tube and the third switch tube are turned on, the first switch tube is turned off, and the second switch unit is driven not to perform a closing action and is turned off; When the control module outputs the second control signal of a low level, the second switch tube and the third switch tube are turned off, the first switch tube is turned on, and drives the second switch unit to perform a closing action and turn on.

10. An electronic device, characterized in that: include: Memory for storing computer programs; A processor is used to execute the computer program to implement the black start method of the energy storage system according to any one of claims 7 to 9.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, a black start method for an energy storage system as described in any one of claims 7 to 9 is implemented.

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