Energy storage converter of flow battery and control method thereof, energy storage system

Abstract

The present disclosure relates to an energy storage converter of a flow battery, a control method thereof and an energy storage system. The energy storage converter comprises a DC / DC module (10), an AC / DC module (20), a switching module (30) and a control module (40); the DC / DC module comprises a plurality of bridge arms connected in parallel, the first and second bus bars of the plurality of bridge arms are connected to the positive and negative poles of the DC side of the AC / DC module respectively; the switching module is connected with the DC / DC module and the flow battery (50) respectively; the control module is used for controlling the conduction and turn-off of each switch in the switching module, and controlling the duty cycle of the pulse width modulation (PWM) signal of the plurality of bridge arms, so that the flow battery enters a starting state or a running state, which can realize the starting of the flow battery and quickly switch to the running state, without the need for additional dedicated starting equipment, and the utilization rate of the flow battery is improved.

Description

Technical Field

[0001] This disclosure relates to the field of energy storage system control, specifically to an energy storage converter for a flow battery and its control method, as well as an energy storage system. Background Technology

[0002] Compared to traditional lithium-ion batteries, flow batteries offer numerous advantages, such as high safety, long lifespan, extended energy storage time, strong scalability, high discharge capacity, strong environmental adaptability, and environmental friendliness. However, some flow batteries, such as vanadium redox flow batteries, exhibit a zero-volt output voltage after initial installation, prolonged inactivity, deep discharge, maintenance, or fault repair. This characteristic stems from the operating principle of flow batteries. Therefore, in applications involving such flow batteries, the energy storage converter needs to possess zero-volt start-up capabilities to accommodate this characteristic. Implementing zero-volt start-up of the flow battery using a separate device within the flow battery converter complicates the system, increases the failure rate, and raises costs. Summary of the Invention

[0003] The purpose of this disclosure is to provide an energy storage converter for a flow battery, a control method thereof, and an energy storage system. The energy storage converter has a simple structure and can quickly switch between the start-up and operation states of the flow battery.

[0004] To achieve the above objectives, this disclosure provides an energy storage converter for a flow battery, the energy storage converter comprising a DC / DC module, an AC / DC module, a switching module, and a control module; The DC / DC module includes multiple bridge arms connected in parallel, and the first and second bus terminals of the multiple bridge arms are respectively connected to the positive and negative terminals of the DC side of the AC / DC module. The switching module is connected to the DC / DC module and the flow battery, respectively. The control module is used to control the on and off of each switch in the switching module, and to control the duty cycle of the PWM signal of the multiple bridge arms, so that the flow battery enters the start-up state or the running state.

[0005] Optionally, the DC / DC module includes a first bridge arm and a second bridge arm, the output point of the first bridge arm is connected to the positive terminal of the flow battery, and the switching module is connected to the positive and negative terminals of the flow battery, the output point of the second bridge arm, and the second bus terminal.

[0006] Optionally, the switch module includes a first contactor and a second contactor, wherein the moving contact of the first contactor is connected to the negative terminal of the flow battery, the first stationary contact of the first contactor is connected to the output point of the second bridge arm, and the second stationary contact of the first contactor is connected to the second bus terminal. The moving contact of the second contactor is connected to the positive terminal of the flow battery, and the stationary contact of the second contactor is connected to the output point of the second bridge arm; The control module is used to respond to a start command indicating that the flow battery is to start, control the moving contact of the first contactor to connect to the first stationary contact of the first contactor, and the moving contact of the second contactor to not connect to the stationary contact of the second contactor, and adjust the duty cycle of the PWM signals of the first bridge arm and the second bridge arm so that the flow battery enters the start state.

[0007] Optionally, the control module is further configured to, in response to receiving an operating command instructing the flow battery to operate, control the moving contact of the first contactor to connect to the second stationary contact of the first contactor, and control the moving contact of the second contactor to connect to the stationary contact of the second contactor, and adjust the duty cycle of the PWM signals of the first bridge arm and the second bridge arm so that the flow battery enters the operating state.

[0008] Optionally, the moving contact of the first contactor is a normally closed contact, the moving contact of the second contactor is a normally open contact, and the first contactor and the second contactor are interlocked.

[0009] This disclosure also provides a control method for an energy storage converter of a flow battery, the energy storage converter including a DC / DC module, an AC / DC module, a switching module, and a control module; the DC / DC module includes multiple bridge arms connected in parallel, the first and second bus terminals of the multiple bridge arms being respectively connected to the positive and negative terminals of the DC side of the AC / DC module; the switching module is connected to both the DC / DC module and the flow battery; The method includes: The switching module controls the on and off states of each switch and the duty cycle of the PWM signals of the multiple bridge arms to enable the flow battery to enter the startup or running state.

[0010] Optionally, the DC / DC module includes a first bridge arm and a second bridge arm, the output point of the first bridge arm is connected to the positive terminal of the flow battery, and the switching module includes a first contactor and a second contactor. The moving contact of the first contactor is connected to the negative terminal of the flow battery, the first stationary contact of the first contactor is connected to the output point of the second bridge arm, and the second stationary contact of the first contactor is connected to the second busbar. The moving contact of the second contactor is connected to the positive terminal of the flow battery, and the stationary contact of the second contactor is connected to the output point of the second bridge arm; The control of turning each switch in the switching module on and off, and the control of the PWM signal duty cycle of the multiple bridge arms, to enable the flow battery to enter the startup or running state, includes: In response to receiving a start command instructing the flow battery to start, the system controls the moving contact of the first contactor to connect to the first stationary contact of the first contactor, and the moving contact of the second contactor to disconnect from the stationary contact of the second contactor. The system then adjusts the duty cycle of the PWM signals of the first bridge arm and the second bridge arm to enable the flow battery to enter the start-up state.

[0011] Optionally, the step of controlling the on and off of each switch in the switching module and controlling the duty cycle of the PWM signals of the multiple bridge arms to enable the flow battery to enter the startup or running state further includes: In response to receiving an operating command instructing the flow battery to operate, the system controls the moving contact of the first contactor to connect to the second stationary contact of the first contactor, and controls the moving contact of the second contactor to connect to the stationary contact of the second contactor. The system also adjusts the duty cycle of the PWM signals of the first bridge arm and the second bridge arm to bring the flow battery into the operating state.

[0012] Optionally, adjusting the duty cycle of the PWM signals of the first bridge arm and the second bridge arm to bring the flow battery into the startup state includes: Adjust the duty cycle of the PWM signals of the first bridge arm and the second bridge arm to adjust the voltage of the output point of the first bridge arm and the output point of the second bridge arm to a predetermined voltage value; Increase the duty cycle of the PWM signal of the upper arm of the first bridge arm and decrease the duty cycle of the PWM signal of the upper arm of the second bridge arm until the voltage at the positive and negative terminals of the flow battery reaches a predetermined voltage, at which point the flow battery is started up.

[0013] This disclosure also provides an energy storage system, including: Multiple flow batteries; According to the energy storage converter provided in this disclosure; A switching module is connected to the energy storage converter and the plurality of flow batteries respectively, and is used to switch the energy storage converter to be connected to any one of the plurality of flow batteries so that the connected flow battery can be started.

[0014] With the above technical solution, the start-up and running states of the flow battery share multiple bridge arms in the DC / DC module. By simply controlling the on and off of the switches and the duty cycle of the bridge arm PWM signals, the zero-volt start-up function of the flow battery can be realized and it can quickly switch to a more efficient running state without the need for additional dedicated start-up equipment, thus improving the utilization rate of the flow battery.

[0015] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of an energy storage converter provided in an exemplary embodiment.

[0017] Figure 2 This is a schematic diagram of the structure of an energy storage converter provided in yet another exemplary embodiment.

[0018] Figure 3 This is an equivalent circuit diagram of the energy storage converter in the startup state provided in an exemplary embodiment.

[0019] Figure 4 This is an equivalent circuit diagram of the operating state of an energy storage converter provided in an exemplary embodiment.

[0020] Figure 5 This is a flowchart of a control method for an energy storage converter provided in an exemplary embodiment.

[0021] Figure 6 This is a flowchart of the startup and operation of an energy storage system provided in an exemplary embodiment.

[0022] Figure 7 This is a block diagram of an electronic device provided in an exemplary embodiment.

[0023] Explanation of reference numerals in the attached figures 10 DC / DC modules; 20 AC / DC modules; 30 switch modules; 40 control module; 50 flow battery; 60 filter module; L1 is the first inductor; L2 is the second inductor; C1 is the first capacitor; C2 is the second capacitor; K1 is the first contactor; K2 is the second contactor; Q1 is the upper arm of the first bridge arm; Q2 is the lower arm of the first bridge arm; Q3 is the upper arm of the second bridge arm; Q4 is the lower arm of the second bridge arm. Detailed Implementation

[0024] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0025] It should be noted that all actions involving the acquisition of signals, information, or data in this disclosure are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with authorization from the owner of the relevant device.

[0026] Figure 1 This is a schematic diagram of the structure of an energy storage converter provided in an exemplary embodiment. For example... Figure 1 As shown, the energy storage converter includes a DC / DC module 10, an AC / DC module 20, a switching module 30, and a control module 40.

[0027] DC / DC module 10 is used for bidirectional DC-DC conversion. AC / DC module 20 includes an AC side and a DC side, used to convert the DC power output from the flow battery after passing through DC / DC module 10 into AC power, or to convert the AC power from the AC bus of the power grid into DC power and then transmit it to DC / DC module 10. DC / DC module 10 includes multiple bridge arms connected in parallel, and the first and second bus terminals of the multiple bridge arms are respectively connected to the positive and negative terminals of the DC side of AC / DC module 20. Figure 1 The DC / DC module 10 is an example that includes two bridge arms.

[0028] Since flow batteries have a large range of DC voltage variations during charging and discharging, a DC / DC topology can be added to the AC / DC topology to adapt to the wide output voltage characteristics of flow batteries. The AC / DC+DC / DC topology can realize the charging and discharging function of flow batteries under a wide voltage range.

[0029] The switching module 30 is connected to both the DC / DC module 10 and the flow battery 50. The control module 40 is connected to both the switching module 30 and the DC / DC module 10. The control module 40 is used to control the on and off of each switch in the switching module 30 and to control the duty cycle of the pulse-width modulation (PWM) signals of multiple bridge arms so that the flow battery 50 enters the startup or running state.

[0030] The switch module 30 may include multiple switches for connecting or turning on the various ports of the DC / DC module 10 and the positive and negative terminals of the flow battery 50.

[0031] With the above technical solution, the start-up and running states of the flow battery share multiple bridge arms in the DC / DC module. By simply controlling the on and off of the switches in the switching module and the duty cycle of the PWM signal of the bridge arm, the zero-volt start-up function of the flow battery can be realized and it can quickly switch to a more efficient running state without the need for additional dedicated start-up equipment, thus improving the utilization rate of the flow battery.

[0032] Figure 2 This is a schematic diagram of the structure of an energy storage converter provided in yet another exemplary embodiment. For example... Figure 2 As shown, the DC / DC module 10 includes a first bridge arm and a second bridge arm. The first bridge arm includes an upper bridge arm (upper tube) Q1 and a lower bridge arm (lower tube) Q2, and the second bridge arm includes an upper bridge arm Q3 and a lower bridge arm Q4. The first bus terminal P of the first and second bridge arms is connected to the positive terminal of the DC side of the AC / DC module 20, and the second bus terminal N of the first and second bridge arms is connected to the negative terminal of the DC side of the AC / DC module 20. The output point U of the first bridge arm is connected to the positive terminal of the flow battery 50, and the switch module 30 is connected to the positive and negative terminals of the flow battery 50, the output point U of the first bridge arm, the output point V of the second bridge arm, and the second bus terminal N. The output point of a bridge arm is the node between the upper and lower bridge arms of that bridge arm.

[0033] exist Figure 2 The energy storage converter also includes a rectifier module 60, which comprises a first inductor L1 and a second inductor L2. The output point U of the first bridge arm is connected to the positive terminal of the flow battery 50 via the first inductor L1, and the output point V of the second bridge arm is connected to the switching module 30 via the second inductor L2. Both the first inductor L1 and the second inductor L2 serve a rectification function. Thus, by setting one inductor in each of the two lines, each inductor can use an inductor with a smaller inductance value. Compared to using only one inductor for filtering in a single line, this method is more cost-effective, flexible, convenient, easier to maintain, and provides better heat dissipation.

[0034] Furthermore, in Figure 2 In this embodiment, the DC / DC module 10 may further include a first capacitor C1 and a second capacitor C2 (e.g., an electrolytic capacitor or a film capacitor). The first capacitor C1 and the second capacitor C2 are connected in series between the positive and negative terminals of the DC side of the AC / DC module 20. The first capacitor C1 and the second capacitor C2 can play a role in voltage regulation, and compared with using a single capacitor for voltage regulation, it is lower in cost, more flexible and convenient, easier to maintain, and has better heat dissipation.

[0035] In another embodiment, the switch module 30 includes a first contactor K1 and a second contactor K2. The moving contact of the first contactor K1 is connected to the negative terminal of the flow battery 50, the first stationary contact A of the first contactor K1 is connected to the output point V of the second bridge arm, and the second stationary contact B of the first contactor K1 is connected to the second bus terminal N.

[0036] The moving contact of the second contactor K2 is connected to the positive terminal of the flow battery 50, and the stationary contact of the second contactor K2 (reusing the first stationary contact A) is connected to the output point V of the second bridge arm.

[0037] The control module 40 is used to respond to the received start command indicating that the flow battery 50 is to start, control the moving contact of the first contactor K1 to connect to the first stationary contact A of the first contactor K1, and the moving contact of the second contactor K2 to not connect to the stationary contact A of the second contactor K2, and adjust the duty cycle of the PWM signal of the first bridge arm and the second bridge arm so that the flow battery 50 enters the start state.

[0038] Figure 3 This is an equivalent circuit diagram of an energy storage converter in the startup state provided in an exemplary embodiment. For example... Figure 3 As shown, in the startup state, the output point U of the first bridge arm (through the first inductor L1) is connected to the positive terminal of the flow battery 50, and the output point V of the second bridge arm (through the second inductor L2) is connected to the negative terminal of the flow battery 50.

[0039] Since the flow battery 50 requires zero-volt startup, the duty cycle of the PWM signals of the first and second bridge arms can be controlled to make the voltage between the positive and negative terminals of the flow battery 50 reach zero volts first, and then gradually increase it.

[0040] In another embodiment, the control module 40 is further configured to, in response to receiving an operation command instructing the flow battery 50 to operate, control the moving contact of the first contactor K1 to connect to the second stationary contact B of the first contactor K1, and control the moving contact of the second contactor K2 to connect to the stationary contact A of the second contactor K2, and adjust the duty cycle of the PWM signals of the first bridge arm and the second bridge arm so that the flow battery 50 enters the operating state.

[0041] Figure 4 This is an equivalent circuit diagram of the operating state of an energy storage converter provided in an exemplary embodiment. For example... Figure 4 As shown, in operation, the output point U of the first bridge arm and the output point V of the second bridge arm are both connected to the positive terminal of the flow battery 50, and the negative terminal of the second busbar, which is the DC side of the AC / DC module 20, is connected to the negative terminal of the flow battery 50.

[0042] When the flow battery 50 is operating normally, the duty cycle of the PWM signal of the first bridge arm and the second bridge arm can be controlled to charge or discharge the flow battery 50.

[0043] The moving contact of the first contactor K1 can be a normally closed contact (e.g., normally closed to the second stationary contact B), and the moving contact of the second contactor K2 can be a normally open contact. The first contactor K1 and the second contactor K2 are interlocked. That is, when the first contactor K1 is energized, its normally closed (auxiliary) contact prevents the second contactor K2 from being energized. When the flow battery 50 starts, the first contactor K1 operates, and its moving contact connects to the first stationary contact A. Therefore, the second contactor K2 cannot be energized and connects to the first stationary contact A. This avoids a short circuit between the positive and negative terminals of the flow battery 50 caused by both the first contactor K1 and the second contactor K2 simultaneously connecting to the first stationary contact A.

[0044] Based on the same inventive concept, this disclosure also provides a control method for a flow battery energy storage converter. Figure 5 This is a flowchart illustrating a control method for an energy storage converter provided in an exemplary embodiment. The energy storage converter includes a DC / DC module 10, an AC / DC module 20, a switching module 30, and a control module 40. The DC / DC module 10 includes multiple bridge arms connected in parallel, with the first and second bus terminals of the multiple bridge arms respectively connected to the positive and negative terminals of the DC side of the AC / DC module 20. The switching module 30 is connected to both the DC / DC module 10 and the flow battery 50.

[0045] Figure 5 This is a flowchart of a control method for an energy storage converter provided in an exemplary embodiment. For example... Figure 5 As shown, the method includes step S101.

[0046] In S101, the switching module 30 controls the on and off of each switch and controls the duty cycle of the PWM signal of multiple bridge arms so that the flow battery 50 enters the start-up state or the running state.

[0047] The switch module 30 may include multiple switches for connecting or turning on the various ports of the DC / DC module 10 and the positive and negative terminals of the flow battery 50.

[0048] With the above technical solution, the start-up and running states of the flow battery share multiple bridge arms in the DC / DC module. By simply controlling the on and off of the switches in the switching module and the duty cycle of the PWM signals of the bridge arms, the flow battery can be started and quickly switched to the running state without the need for additional dedicated start-up equipment, thus improving the utilization rate of the flow battery.

[0049] In another embodiment, the DC / DC module 10 includes a first bridge arm and a second bridge arm, the output point of the first bridge arm is connected to the positive terminal of the flow battery 50, and the switch module 30 includes a first contactor K1 and a second contactor K2.

[0050] The moving contact of the first contactor K1 is connected to the negative terminal of the flow battery 50, the first stationary contact of the first contactor K1 is connected to the output point of the second bridge arm, and the second stationary contact of the first contactor K1 is connected to the second bus terminal. The moving contact of the second contactor K2 is connected to the positive terminal of the flow battery 50, and the stationary contact of the second contactor K2 is connected to the output point of the second bridge arm.

[0051] In this embodiment, the steps of controlling the on and off of each switch in the control switch module 30 and controlling the duty cycle of the PWM signals of multiple bridge arms to enable the flow battery 50 to enter the startup state or the running state include: In response to receiving a start command indicating that the flow battery 50 is to start, the moving contact of the first contactor K1 is connected to the first stationary contact of the first contactor K1, and the moving contact of the second contactor K2 is not connected to the stationary contact of the second contactor K2. The duty cycle of the PWM signals of the first bridge arm and the second bridge arm is adjusted so that the flow battery 50 enters the start state.

[0052] The start command can be sent under predetermined conditions. Since the flow battery has a zero-volt start function, a start command can be sent when the flow battery voltage is less than a predetermined first threshold.

[0053] The steps of controlling the on / off state of each switch in the control switch module 30 and controlling the duty cycle of the PWM signals of multiple bridge arms to bring the flow battery 50 into the startup or running state may further include: In response to receiving an operation command instructing the flow battery 50 to operate, the moving contact of the first contactor K1 is connected to the second stationary contact of the first contactor K1, and the moving contact of the second contactor K2 is connected to the stationary contact of the second contactor K2. The duty cycle of the PWM signals of the first bridge arm and the second bridge arm is adjusted so that the flow battery 50 enters the operating state.

[0054] The operation command can be a command sent under predetermined conditions. When the flow battery is in the startup state, if the voltage of the flow battery is greater than a second threshold, an operation command can be sent. The second threshold can be greater than the first threshold.

[0055] At this point, the circuit equivalent diagram is as follows: Figure 4 As shown, the DC output terminals U and V of the energy storage converter can be interleaved to minimize the current ripple of the flow battery. Normal operation of the flow battery is achieved by controlling its charging and discharging current or the positive and negative terminal voltages (e.g., control modes including current control, power control, and voltage control). In this operating mode, the flow battery exhibits high charging and discharging efficiency, low voltage and current ripple, and good dynamic power conversion characteristics, meeting the normal operation requirements of the energy storage system.

[0056] In another embodiment, adjusting the duty cycle of the PWM signals of the first and second bridge arms to bring the flow battery 50 into the startup state includes: Adjust the duty cycle of the PWM signals of the first bridge arm and the second bridge arm to adjust the voltage of the output point U of the first bridge arm and the output point V of the second bridge arm to the predetermined voltage value. Increase the duty cycle of the PWM signal of the upper arm (upper tube) of the first bridge arm (decrease the duty cycle of the PWM signal of the lower arm (lower tube) of the first bridge arm), and decrease the duty cycle of the PWM signal of the upper arm of the second bridge arm (increase the duty cycle of the PWM signal of the lower arm of the second bridge arm) until the voltage at the positive and negative terminals of the flow battery 50 reaches the predetermined voltage, at which point the flow battery 50 is started.

[0057] The duty cycle can be controlled to increase or decrease slowly and gradually. The charging time can be set by the duty cycle change rate of the PWM signal. During startup, current control can be added to generate a PWM signal to enable the flow battery to be charged at any current.

[0058] During grid startup, the DC bus (the bus where point P is located) is pre-charged first. Then, the contactor in the control switch module 30 is used to make the circuit equivalent to... Figure 3 The structure uses the duty cycle of the PWM signals of the first and second bridge arms to adjust the voltages at both output points U and V to predetermined values. This ensures that the positive and negative voltages of the flow battery are equal, with a voltage difference of zero V, enabling zero-volt start-up. This predetermined voltage value can be, for example, half the DC bus voltage, resulting in a 50% duty cycle, which is easier to control and has a smaller error.

[0059] When the voltage difference reaches zero volts, charging can begin. The duty cycle of the PWM signal on the upper arm of the first bridge arm is increased, while the duty cycle of the PWM signal on the upper arm of the second bridge arm is decreased, thus achieving controllable changes in the voltage difference at the flow battery ports. Specifically, closed-loop control can be implemented on the output current at both ports of the flow battery, ensuring controllable current during zero-volt startup, preventing current surges to the flow battery, and guaranteeing its lifespan.

[0060] In a multi-flow battery energy storage system, the energy storage converter can also be installed in an external junction box or automatic distribution box, and the energy storage converter provided in this disclosure can be used to start multiple flow batteries in the energy storage system one by one.

[0061] This disclosure also provides an energy storage system, including multiple flow batteries, an energy storage converter provided in this disclosure, and a switching module. The switching module is connected to the energy storage converter and the multiple flow batteries respectively, and is used to switch the energy storage converter to be connected to any one of the multiple flow batteries, so as to enable the connected flow battery to start.

[0062] The energy storage converter can be installed inside a junction box or automatic distribution box. After zero-volt startup of the current flow battery, it can switch to connect to the next flow battery requiring zero-volt startup and control its startup. In this way, in a multi-flow battery energy storage system, only one energy storage converter is needed to achieve zero-volt startup of multiple flow batteries, and regular maintenance of different flow batteries is also possible. Consequently, some energy storage converters in the energy storage system do not need zero-volt startup functionality and only have normal operation functionality, thereby reducing the overall system investment, reducing system maintenance workload, and improving the degree of automation in operation and maintenance.

[0063] Figure 6 This is a flowchart illustrating the startup and operation of an energy storage system as provided in an exemplary embodiment. Figure 6 As shown, when the energy storage system starts up and runs, the following steps are performed: 1. Perform a self-test on the energy storage system; 2. If the self-test is normal, initialize the parameters of the energy storage system; 3. Precharge the DC bus; 4. After the DC bus pre-charging is completed, check the voltage of the flow battery; 5. Determine the flow battery mode based on the flow battery voltage. When the flow battery voltage is less than the first threshold, the flow battery can be instructed to enter the start-up mode. When the flow battery voltage is greater than the second threshold, the flow battery can be instructed to enter the operation mode. 6. When the flow battery enters the start-up mode, it starts up according to the control strategy of the start-up mode, which may include the zero-volt start-up strategy mentioned above. 7. When the flow battery enters the operating mode, it operates according to the control strategy of the operating mode, which may include the operating mode control strategy mentioned above. 8. When the flow battery is in startup mode and its voltage is greater than the second threshold, the flow battery can be instructed to enter operating mode. 9. When the flow battery is in operation mode and a fault is detected, the relevant equipment can be shut down.

[0064] Figure 7 This is a block diagram illustrating an electronic device 700 according to an exemplary embodiment. Figure 7 As shown, the electronic device 700 may include a processor 701 and a memory 702. The electronic device 700 may also include one or more of a multimedia component 703, an input / output (I / O) interface 704, and a communication component 705.

[0065] The processor 701 controls the overall operation of the electronic device 700 to complete all or part of the steps in the control method for the energy storage converter described above. The memory 702 stores various types of data to support the operation of the electronic device 700. This data may include, for example, instructions for any application or method operating on the electronic device 700, and application-related data such as contact data, sent and received messages, pictures, audio, video, etc. The memory 702 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The multimedia component 703 may include a screen and audio components. The screen may be, for example, a touchscreen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in memory 702 or transmitted via communication component 705. The audio component also includes at least one speaker for outputting audio signals. I / O interface 704 provides an interface between processor 701 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons may be virtual or physical buttons. Communication component 705 is used for wired or wireless communication between the electronic device 700 and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, 4G, NB-IoT, eMTC, or other 5G technologies, or combinations thereof, is not limited here. Therefore, the corresponding communication component 705 may include: a Wi-Fi module, a Bluetooth module, an NFC module, etc.

[0066] In an exemplary embodiment, the electronic device 700 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to execute the control method for the energy storage converter described above.

[0067] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, which, when executed by a processor, implement the steps of the control method for the energy storage converter described above. For example, the computer-readable storage medium may be the memory 702 including program instructions described above, which may be executed by the processor 701 of the electronic device 700 to complete the control method for the energy storage converter described above.

[0068] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0069] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0070] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A flow battery energy storage converter, characterized in that, The energy storage converter includes a DC / DC / DC module (10), an AC / DC / DC module (20), a switching module (30), and a control module (40). The DC / DC module (10) includes multiple bridge arms connected in parallel, and the first and second bus terminals of the multiple bridge arms are respectively connected to the positive and negative terminals of the DC side of the AC / DC module (20). The switch module (30) is connected to the DC / DC module (10) and the flow battery (50) respectively; The control module (40) is used to control the on and off of each switch in the switch module (30) and to control the duty cycle of the pulse width modulation (PWM) signal of the multiple bridge arms so that the flow battery (50) enters the start-up state or the running state.

2. The energy storage converter according to claim 1, characterized in that, The DC / DC module (10) includes a first bridge arm and a second bridge arm. The output point of the first bridge arm is connected to the positive terminal of the flow battery (50). The switch module (30) is connected to the positive and negative terminals of the flow battery (50), the output point of the second bridge arm, and the second bus terminal.

3. The energy storage converter according to claim 2, characterized in that, The switch module (30) includes a first contactor (K1) and a second contactor (K2). The moving contact of the first contactor (K1) is connected to the negative terminal of the flow battery (50). The first stationary contact of the first contactor (K1) is connected to the output point of the second bridge arm. The second stationary contact of the first contactor (K1) is connected to the second bus terminal. The moving contact of the second contactor (K2) is connected to the positive terminal of the flow battery (50), and the stationary contact of the second contactor (K2) is connected to the output point of the second bridge arm; The control module (40) is used to respond to a start command that instructs the flow battery (50) to start, control the moving contact of the first contactor (K1) to connect to the first stationary contact of the first contactor (K1), and the moving contact of the second contactor (K2) to not connect to the stationary contact of the second contactor (K2), and adjust the duty cycle of the PWM signals of the first bridge arm and the second bridge arm so that the flow battery (50) enters the start state.

4. The energy storage converter according to claim 3, characterized in that, The control module (40) is also configured to, in response to receiving an operating command instructing the flow battery (50) to operate, control the moving contact of the first contactor (K1) to connect to the second stationary contact of the first contactor (K1), and control the moving contact of the second contactor (K2) to connect to the stationary contact of the second contactor (K2), and adjust the duty cycle of the PWM signals of the first bridge arm and the second bridge arm so that the flow battery (50) enters the operating state.

5. The energy storage converter according to claim 4, characterized in that, The moving contact of the first contactor (K1) is a normally closed contact, and the moving contact of the second contactor (K2) is a normally open contact. The first contactor (K1) and the second contactor (K2) are interlocked.

6. A control method for an energy storage converter of a flow battery (50), characterized in that, The energy storage converter includes a DC / DC module (10), an AC / DC module (20), a switching module (30), and a control module (40); the DC / DC module (10) includes multiple bridge arms connected in parallel, and the first and second bus terminals of the multiple bridge arms are respectively connected to the positive and negative terminals of the DC side of the AC / DC module (20); the switching module (30) is connected to the DC / DC module (10) and the flow battery (50) respectively; The method includes: Control the on and off of each switch in the switching module (30), and control the duty cycle of the PWM signal of the multiple bridge arms so that the flow battery (50) enters the start-up state or the running state.

7. The method according to claim 6, characterized in that, The DC / DC module (10) includes a first bridge arm and a second bridge arm. The output point of the first bridge arm is connected to the positive terminal of the flow battery (50). The switch module (30) includes a first contactor (K1) and a second contactor (K2). The moving contact of the first contactor (K1) is connected to the negative terminal of the flow battery (50), the first stationary contact of the first contactor (K1) is connected to the output point of the second bridge arm, and the second stationary contact of the first contactor (K1) is connected to the second bus terminal. The moving contact of the second contactor (K2) is connected to the positive terminal of the flow battery (50), and the stationary contact of the second contactor (K2) is connected to the output point of the second bridge arm; The control of turning each switch in the switching module (30) on and off, and the control of the duty cycle of the PWM signals of the multiple bridge arms, so that the flow battery (50) enters the startup state or the running state, includes: In response to receiving a start command instructing the flow battery (50) to start, the moving contact of the first contactor (K1) is connected to the first stationary contact of the first contactor (K1), and the moving contact of the second contactor (K2) is not connected to the stationary contact of the second contactor (K2). The duty cycle of the PWM signals of the first bridge arm and the second bridge arm is adjusted so that the flow battery (50) enters the start state.

8. The method according to claim 7, characterized in that, The method of controlling the on and off of each switch in the switching module (30) and controlling the duty cycle of the PWM signals of the multiple bridge arms to enable the flow battery (50) to enter the startup or running state also includes: In response to receiving an operating command instructing the flow battery (50) to operate, the moving contact of the first contactor (K1) is controlled to connect to the second stationary contact of the first contactor (K1), and the moving contact of the second contactor (K2) is controlled to connect to the stationary contact of the second contactor (K2). The duty cycle of the PWM signals of the first bridge arm and the second bridge arm is adjusted so that the flow battery (50) enters the operating state.

9. The method according to claim 7, characterized in that, Adjusting the duty cycle of the PWM signals of the first bridge arm and the second bridge arm to bring the flow battery (50) into the startup state includes: Adjust the duty cycle of the PWM signals of the first bridge arm and the second bridge arm to adjust the voltage of the output point of the first bridge arm and the output point of the second bridge arm to a predetermined voltage value; Increase the duty cycle of the PWM signal of the upper arm of the first bridge arm and decrease the duty cycle of the PWM signal of the upper arm of the second bridge arm until the voltage at the positive and negative terminals of the flow battery (50) reaches the predetermined voltage, and the flow battery (50) is started.

10. An energy storage system, characterized in that, include: Multiple flow batteries; The energy storage converter according to any one of claims 1-5; A switching module is connected to the energy storage converter and the plurality of flow batteries respectively, and is used to switch the energy storage converter to be connected to any one of the plurality of flow batteries so that the connected flow battery can be started.

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