Energy storage converter and control method thereof

Abstract

The invention discloses an energy storage converter and a control method thereof, and the energy storage converter is used for being connected between a battery and a load, and comprises a DC power distribution module which comprises a plurality of DC switch groups of different types, and the DC switch groups are used for switching on and off the electric energy output of the battery; the power conversion module is connected with the direct-current switch group and is used for performing power conversion on the electric energy output of the battery and then providing the converted electric energy to a load; and the control module is connected with the direct-current power distribution module and the power conversion module, and is used for controlling the on-off of the direct-current switch group and controlling the operation or stop of the power conversion module. According to the energy storage converter, the power distribution output of the battery to the load can be realized without externally connecting a high-voltage box, the power density of the energy storage system is improved, and the operation cost of the energy storage system is reduced.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to an energy storage converter and a control method thereof. Background Art

[0002] With the development of energy storage technology, the requirements for the cost and power density of energy storage systems are getting higher and higher. The energy storage converter (PCS, Power Conversion System) is an important component of the energy storage system. The energy storage converter is a device that controls the charging and discharging process of the battery and performs AC-DC conversion. It can directly supply power to the AC load without a power grid, and plays a role in regulating active power and reactive power in the power grid. The current mainstream solution of the energy storage system is to connect a high-voltage box after the battery cluster. The battery current comes out of the high-voltage box and then connects to the energy storage converter (PCS). The independent high-voltage box occupies most of the space of the energy storage system. Some switching devices in the high-voltage box have the same functions as the switching devices in the energy storage converter, which makes the overall power density of the energy storage system low and the system operation cost high. Summary of the invention

[0003] The embodiment of the present invention provides an energy storage converter and a control method thereof, aiming to solve the problem of low system power density caused by duplicate functions of the energy storage converter and the high-voltage box in the energy storage system.

[0004] In a first aspect, an embodiment of the present invention provides an energy storage converter, which is used to be connected between a battery and a load, and includes:

[0005] A DC power distribution module, comprising a plurality of DC switch groups of different types, wherein the DC switch groups are used to switch on and off the power output of the battery;

[0006] A power conversion module, connected to the DC switch group, for performing power conversion on the electric energy output by the battery to provide it to the load;

[0007] The control module is connected to the DC switch group and the power conversion module, and is used to control the on and off of the DC switch group, and control the power conversion module to run or stop.

[0008] In the energy storage inverter provided in an embodiment of the present invention, the multiple different types of DC switch groups include a first switch group, a second switch group and a third switch group connected in sequence, the first switch group is connected to the battery, the third switch group is connected to the power conversion module and the control module, wherein the control module is used to control the on and off of the third switch group.

[0009] In the energy storage converter provided in an embodiment of the present invention, the DC power distribution module further includes a DC soft start unit, which is connected to the third switch group and the power conversion module, wherein the DC soft start unit is used to soft-start the on and off of the third switch group.

[0010] In the energy storage inverter provided in an embodiment of the present invention, the third switch group includes a first controlled breaking device and a second controlled breaking device, the first controlled breaking device and the second controlled breaking device are both connected to the power conversion module and the control module, and at least one of the first controlled breaking device and the second controlled breaking device is connected to the DC soft start unit.

[0011] In the energy storage inverter provided in an embodiment of the present invention, the control module includes a control module and a drive module, the control module is connected to the drive module and the power conversion module, and the drive module is connected to the first controlled disconnecting device and the second controlled disconnecting device, wherein the control module is used to drive the first controlled disconnecting device and the second controlled disconnecting device to be turned on and off through the drive module, and to control the power conversion module to run or stop.

[0012] In the energy storage converter provided by an embodiment of the present invention, the control module includes a main control unit and a sampling control unit, the driving module includes a first driving unit and a second driving unit, the first driving unit is connected to the main control unit and the first controlled disconnecting device, the sampling control unit is connected to the main control unit, the second driving unit and the power conversion module, and the second driving unit is connected to the second controlled disconnecting device, wherein the main control unit is used to drive the first controlled disconnecting device to be turned on and off through the first driving unit, and the sampling control unit is used to drive the second controlled disconnecting device to be turned on and off through the second driving unit, and control the power conversion module to run or stop.

[0013] In the energy storage converter provided in an embodiment of the present invention, the control module includes a main control unit and a sampling control unit, the drive module includes a first drive unit and a second drive unit, the main control unit is connected to the first drive unit and the second drive unit, the first controlled breaking device and the second controlled breaking device are respectively connected to the first drive unit and the second drive unit, the sampling control unit is connected to the main control unit and the power conversion module, wherein the main control unit is used to drive the first controlled breaking device and the second controlled breaking device to be turned on and off respectively through the first drive unit and the second drive unit, and the sampling control unit is used to control the power conversion module to run or stop.

[0014] In the energy storage inverter provided in an embodiment of the present invention, the first switch group includes a first mechanical disconnecting device and a second mechanical disconnecting device, the first mechanical disconnecting device and the second mechanical disconnecting device are respectively connected to the positive and negative poles of the battery, and the second switch group is connected after the first mechanical disconnecting device and the second mechanical disconnecting device.

[0015] In the energy storage converter provided by the embodiment of the present invention, the second switch group includes a first DC fuse device and a second DC fuse device, and the first DC fuse device and the second DC fuse device are connected between the first switch group and the third switch group.

[0016] In a second aspect, an embodiment of the present invention provides a control method for an energy storage inverter, which is applied to the energy storage inverter described in the first aspect above, and the method includes: detecting whether a battery fails; if the battery fails, controlling the DC switch group to disconnect after a first preset time delay, and controlling the power conversion module to stop after a second preset time delay, wherein the second preset time is less than the first preset time.

[0017] The embodiment of the present invention provides an energy storage inverter and a control method thereof. The energy storage inverter is used to be connected between a battery and a load, and includes: a DC distribution module, including a plurality of different types of DC switch groups, the DC switch group is used to switch on and off the power output of the battery; a power conversion module, connected to the DC switch group, used to perform power conversion on the power output of the battery to provide it to the load; a control module, connected to the DC switch group and the power conversion module, used to control the switching on and off of the DC switch group, and control the operation or stop of the power conversion module. The energy storage inverter of the present application is composed of a DC distribution module, a power conversion module and a control module as a whole. The DC distribution module includes a plurality of different types of DC switch groups, which integrate the corresponding distribution switch devices of the high-voltage box, thereby improving the power density of the energy storage system, and realizing the distribution output of the battery to the load without an external high-voltage box, thereby reducing the operating cost of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0019] Figure 1 A schematic diagram of the structure of an energy storage converter in an application scenario provided by an embodiment of the present invention;

[0020] Figure 2A schematic diagram of the structure of an energy storage converter provided in an embodiment of the present invention;

[0021] Figure 3 Another structural schematic diagram of the energy storage converter provided by an embodiment of the present invention;

[0022] Figure 4 A schematic diagram of the structure of an energy storage system provided by an embodiment of the present invention;

[0023] Figure 5 A schematic diagram of a flow chart of a control method for an energy storage converter provided by an embodiment of the present invention;

[0024] Figure 6 Another schematic flow chart of a control method for an energy storage converter provided by an embodiment of the present invention;

[0025] The reference numerals in the figures are:

[0026] 100, energy storage converter; 10, DC power distribution module; 11, first switch group; 12, second switch group; 13, third switch group; 20, power conversion module; 30, control module; 31, control module; 311, main control unit; 312, sampling control unit; 32, drive module; 321, first drive unit; 322, second drive unit; 40, DC soft start unit; 200, energy storage system; 201, load; 202, battery module. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The directional terms mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present invention, but are not used to limit the present invention. In addition, in the drawings, structures with similar or identical structures are represented by the same reference numerals.

[0029] The embodiment of the present invention proposes an energy storage converter 100 to solve the problem of low system power density caused by repeated functions of the energy storage converter and the high-voltage box in the energy storage system. The specific ideas are as follows:

[0030] The energy storage inverter 100 is mainly divided into three parts: a DC distribution module 10, a power conversion module 20 and a control module 30. The DC distribution module 10 is composed of a plurality of different types of DC switch groups, which can be used to switch on and off the power output of the battery. The power conversion module 20 is connected to the DC switch group to convert the power output of the battery to provide it to the load. The control module 30 is connected to the DC switch group and the power conversion module 20 to control the switching of the DC switch group and control the power conversion module 20 to run or stop.

[0031] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0032] See also Figures 1 to 3 For details, please refer to Figure 1 The embodiment of the present invention shows an energy storage inverter 100, which is used to be connected between a battery and a load, and includes: a DC distribution module 10, including a plurality of DC switch groups of different types, and the DC switch group is used to switch on and off the power output of the battery; a power conversion module 20, connected to the DC switch group, used to convert the power output of the battery to provide it to the load; a control module 30, connected to the DC switch group and the power conversion module 20, used to control the switching of the DC switch group, and control the operation or stop of the power conversion module 20.

[0033] In a specific implementation, the energy storage converter 100 is used to connect between the battery and the load in actual application, and the electric energy of the battery is distributed to the load for use via the energy storage converter 100. Specifically, the energy storage converter 100 is mainly composed of a DC distribution module 10, a power conversion module 20 and a control module 30. The DC distribution module 10 is mainly composed of a plurality of different types of DC switch groups, each DC switch group is composed of one or more switch devices of the same type, and usually a DC switch group is composed of two switch devices of the same type. These switch devices may include electronically controlled switch devices, manual mechanical disconnection switch devices, and automatic disconnection switch devices. Each DC switch group can independently realize the switching of DC power. The power conversion module 20 is connected after the DC switch group, and is mainly used to convert the electric energy output by the battery and provide it to the load for use. The power conversion module 20 is a topological structure composed of multiple power switch tubes such as IGBT, which can realize the power conversion of DC power. The control module 30 is connected to the DC power distribution module 10 and the power conversion module 20. The control module 30 is composed of one or more control circuits combined with IC chips. The control module 30 is used to control the DC switch group in the DC power distribution module 10 to switch on and off. At the same time, the control module 30 is also used to control the power conversion module 20 to run or control the power conversion module 20 to stop. The scenarios for triggering the control module 30 to perform control may include battery failure, manual control, etc. For example, in actual applications, if the battery fails, through fault detection, the control module 30 will control the working power conversion module 20 to stop running, and will also control the DC switch group to cut off the battery's power output to ensure the safety of the load. In general, the multiple different types of DC switch groups in the DC power distribution module 10 of the energy storage converter 100 have integrated the corresponding types of distribution switch devices in the high-voltage box. The battery management function can be realized independently with the control of the control module 30. The battery does not need to be connected to the high-voltage box to directly distribute power to the load, which improves the power density of the energy storage system and reduces the overall operating cost of the energy storage system.

[0034] The energy storage inverter of this embodiment is composed of a DC distribution module, a power conversion module and a control module. The DC distribution module includes multiple DC switch groups of different types, which integrate the corresponding distribution switch devices of the high-voltage box, thereby improving the power density of the energy storage system. The battery can also distribute power to the load without an external high-voltage box, thereby reducing the operating cost of the energy storage system.

[0035] In one embodiment, referring to Figures 1 to 3, the plurality of different types of DC switch groups include a first switch group 11, a second switch group 12, and a third switch group 13 connected in sequence, the first switch group 11 is connected to the battery, the third switch group 13 is connected to the power conversion module 20 and the control module 30, wherein the control module 30 is used to control the on and off of the third switch group 13. In a specific implementation, the plurality of different types of DC switch groups are mainly divided into three groups, namely the first switch group 11, the second switch group 12, and the third switch group 13, the first switch group 11, the second switch group 12, and the third switch group 13 are connected in sequence, the first switch group 11 is connected to the battery, the third switch group 13 is connected to the power conversion module 20 and the control module 30, the third switch group 13 is turned on and off under the control of the control module 30, and the second switch group 12 is connected between the first switch group 11 and the third switch group 13. The switch devices constituting the first switch group 11, the second switch group 12 and the third switch group 13 are switch devices of different types, wherein the first switch group 11 can be constituted by a mechanical switch device that can be turned on and off manually, the second switch group 12 can be constituted by a protective switch device that can be turned on and off automatically, and the third switch group 13 can be constituted by an electrically controlled switch device. In practical applications, the first switch group 11, the second switch group 12 and the third switch group 13 can all individually turn on and off the power output of the battery. In the process of supplying power to the load, the power output of the battery is sequentially input to the power conversion module 20 through the first switch group 11, the second switch group 12 and the third switch group 13, and is output to the load for use after being converted by the power conversion module 20. If one of the first switch group 11, the second switch group 12 and the third switch group 13 is in a disconnected state, the power output of the battery will be cut off, the power conversion module 20 has no power input, and the load has no input. In general, the DC power distribution module 10 integrates three different types of switch groups, namely the first switch group 11, the second switch group 12, and the third switch group 13, and has integrated the corresponding types of distribution switch devices in the traditional high-voltage box, thereby reducing the power density of the energy storage system.

[0036] Further, refer to Figures 1 to 3, the DC power distribution module 10 further includes a DC soft start unit 40, the DC soft start unit 40 is connected to the third switch group 13 and the power conversion module 20, wherein the DC soft start unit 40 is used to soft start the on and off of the third switch group 13. In a specific implementation, the DC power distribution module 10 further includes a DC soft start unit 40, the DC soft start unit 40 is connected to the third switch group 13 and the power conversion module 20, the third switch group 13 is used as a switch group connected to the input side of the power conversion module 20, and the third switch group 13 has a large impact current during the on and off process, so the impact current is reduced by the DC soft start unit 40, and the DC soft start unit 40 can be specifically designed with a capacitor. In actual applications, the first switch group 11 and the second switch group 12 are in a normally closed conduction state. When the machine is just turned on, the third switch group 13 is in a disconnected state by default. The current from the battery passes through the first switch group 11 and the second switch group 12, and then enters the power conversion module 20 through the DC soft start unit 40 to charge the DC bus in the power conversion module 20. Due to the limitation of the DC soft start unit 40, the charging current will not be too large. When the voltages on both sides are basically the same, the control module 30 controls the third switch group 13 to turn on, ensuring that the impact current of the third switch group 13 is at a low level, will not damage the switching devices in the third switch group 13, and improve the reliability of the system.

[0037] Furthermore, refer to Figures 1 to 3, the third switch group 13 includes a first controlled disconnecting device K1 and a second controlled disconnecting device K2, both of which are connected to the power conversion module 20 and the control module 30, and at least one of the first controlled disconnecting device K1 and the second controlled disconnecting device K2 is connected to the DC soft start unit 40. In a specific implementation, the third switch device group is mainly composed of a first controlled disconnecting device K1 and a second controlled disconnecting device K2, and both the first controlled disconnecting device K1 and the second controlled disconnecting device K2 are the same type of electrically controlled switches, such as MOS tubes, relays, etc. The first controlled disconnecting device K1 and the second controlled disconnecting device K2 are used as switches on the positive and negative branches of the system, respectively. The first controlled disconnecting device K1 and the second controlled disconnecting device K2 are both switched on and off under the control of the output control signal of the control module 30. The DC soft-start unit 40 is provided with multiple first controlled breaking devices K1 and second controlled breaking devices K2, at least one of which is connected to the DC soft-start unit 40. It can be that only the first controlled breaking device K1 is connected to the DC soft-start unit 40, or only the second controlled breaking device K2 is connected to the DC soft-start unit 40, or both the first controlled breaking device K1 and the second controlled breaking device K2 are connected to the DC soft-start unit 40. The first controlled disconnecting device K1 and the second controlled disconnecting device K2 are turned on in a certain order. At the beginning, both the first controlled disconnecting device K1 and the second controlled disconnecting device K2 are in the disconnected state. When the first controlled disconnecting device K1 is controlled to be closed and turned on first, the battery and the DC bus of the power conversion module 20 cannot form a charging circuit at this time. When the second controlled disconnecting device K2 is turned on, the battery and the DC bus of the power conversion module 20 will form a charging circuit. Therefore, the one of the first controlled disconnecting device K1 and the second controlled disconnecting device K2 that is closed and turned on later will be subjected to the impact of current. Therefore, the first controlled disconnecting device K1 alone is connected to the DC soft-start unit 40, which is suitable for application scenarios in which the first controlled disconnecting device K1 is turned on later; the second controlled disconnecting device K2 alone is connected to the DC soft-start unit 40, which is suitable for application scenarios in which the second controlled disconnecting device K2 is turned on later; and both the first controlled disconnecting device K1 and the second controlled disconnecting device K2 are connected to the DC soft-start unit 40, which can be suitable for scenarios in which the closing and turning-on sequence is not distinguished. In general, the design can be selected according to the actual application scenario.

[0038] In one embodiment, referring to Figures 1 to 3The control module 30 includes a control module 31 and a drive module 32. The control module 31 is connected to the drive module 32 and the power conversion module 20. The drive module 32 is connected to the first controlled disconnecting device K1 and the second controlled disconnecting device K2. The control module 31 is used to drive the first controlled disconnecting device K1 and the second controlled disconnecting device K2 to be turned on and off through the drive module 32, and to control the power conversion module 20 to run or stop. In a specific implementation, the control module 30 is mainly composed of a control module 31 and a drive module 32. The control module 31 is connected to the drive module 32. The control module 31 is specifically a module structure integrating one or more IC chips, which can realize logical operations and control. The drive module 32 is specifically a drive circuit that can drive the first controlled disconnecting device K1 and the second controlled disconnecting device K2 to be turned on and off. The drive module 32 is controlled by the drive signal of the control module 31. In practical applications, the driving module 32 drives the first controlled disconnecting device K1 and the second controlled disconnecting device K2 to be turned on and off by outputting a driving signal. At the same time, the control module 31 can output a control signal to directly control the power conversion module 20 to run or stop, and can also control the output power of the power conversion module 20.

[0039] Further, refer to Figure 1 and Figure 2The control module 31 includes a main control unit 311 and a sampling control unit 312, and the driving module 32 includes a first driving unit 321 and a second driving unit 322. The first driving unit 321 is connected to the main control unit 311 and the first controlled disconnecting device K1, the sampling control unit 312 is connected to the main control unit 311, the second driving unit 322 and the power conversion module 20, and the second driving unit 322 is connected to the second controlled disconnecting device K2, wherein the main control unit 311 is used to drive the first controlled disconnecting device K1 to be turned on and off through the first driving unit 321, and the sampling control unit 312 is used to drive the second controlled disconnecting device K2 to be turned on and off through the second driving unit 322, and control the power conversion module 20 to run or stop. In a specific implementation, the control module 31 is mainly composed of the main control unit 311 and the sampling control unit 312, and the driving module 32 is mainly composed of the first driving unit 321 and the second driving unit 322. The main control unit 311 is specifically a control board with an integrated BMS chip. The first drive unit 321 is connected to the main control unit 311 and the first controlled disconnecting device K1. The first drive unit 321 is specifically a drive circuit for driving the first controlled disconnecting device K1 to switch on and off. The first drive unit 321 is controlled by the main control unit 311 to drive the first controlled disconnecting device K1 to switch on and off. The sampling control unit 312 is connected to the main control unit 311, the second drive unit 322 and the power conversion module 20. The second drive unit 322 is connected to the second controlled disconnecting device K2. The second drive unit 322 is specifically a drive circuit that drives the second controlled disconnecting device K2 to be turned on and off. The second drive unit 322 is controlled by the sampling control unit 312 to drive the second controlled disconnecting device K2 to be turned on and off. The sampling control unit 312 can control the power conversion module 20 to run or stop. Specifically, the sampling control unit 312 controls the power conversion module 20 by controlling the on and off of the semiconductor power devices in the power conversion module 20, thereby making the power conversion module 20 run or stop. The sampling control unit 312 is controlled by the main control unit 311. The main control unit 311 and the sampling control unit 312 can exchange data in two ways. One is to exchange data through RS485 or CAN. The exchange data includes but is not limited to battery status, voltage, current, and driving signal of the sampling control circuit. The other is digital communication. Digital communication refers to communication through DI (Digital Input) signal or DO (Digital Output) signal, and is not limited to one DI or DO control signal.

[0040] In one embodiment, referring to Figure 3The control module 31 includes a main control unit 311 and a sampling control unit 312, and the driving module 32 includes a first driving unit 321 and a second driving unit 322. The main control unit 311 is connected to the first driving unit 321 and the second driving unit 322, and the first controlled disconnecting device K1 and the second controlled disconnecting device K2 are respectively connected to the first driving unit 321 and the second driving unit 322, and the sampling control unit 312 is connected to the main control unit 311 and the power conversion module 20, wherein the main control unit 311 is used to drive the first controlled disconnecting device K1 and the second controlled disconnecting device K2 to be turned on and off through the first driving unit 321 and the second driving unit 322, and the sampling control unit 312 is used to control the power conversion module 20 to run or stop. In a specific implementation, the control module 31 is mainly composed of the main control unit 311 and the sampling control unit 312, and the driving module 32 is mainly composed of the first driving unit 321 and the second driving unit 322. In this embodiment, both the first drive unit 321 and the second drive unit 322 are connected to the main control unit 311, and the first controlled disconnecting device K1 and the second controlled disconnecting device K2 are connected to the first drive unit 321 and the second drive unit 322 respectively. The main control unit 311 is specifically a control board with an integrated BMS chip, the first drive unit 321 is a drive circuit for driving the first controlled disconnecting device K1 to be turned on and off, and the second drive unit 322 is a drive circuit for driving the second controlled disconnecting device K2 to be turned on and off. Both the first drive unit 321 and the second drive unit 322 are controlled by the main control unit 311 to drive the first controlled disconnecting device K1 and the second controlled disconnecting device K2 to be turned on and off respectively. The sampling control unit 312 is used alone to control the power conversion module 20 to run or stop. Specifically, the sampling control unit 312 controls the power conversion module 20 by controlling the on and off of the semiconductor power devices in the power conversion module 20, so as to make the power conversion module 20 run or stop. The sampling control unit 312 is controlled by the main control unit 311. The main control unit 311 and the sampling control unit 312 can exchange data in two ways. One is to exchange data through RS485 or CAN. The exchange data includes but is not limited to battery status, voltage, current, and driving signal of the sampling control circuit. The other is digital communication. Digital communication refers to communication through DI (Digital Input) signal or DO (Digital Output) signal, and is not limited to one DI or DO control signal.

[0041] In one embodiment, referring to Figures 1 to 3, the first switch group 11 includes a first mechanical disconnecting device K3 and a second mechanical disconnecting device K4, the first mechanical disconnecting device K3 and the second mechanical disconnecting device K4 are respectively connected to the positive and negative poles of the battery, and the second switch group 12 is connected after the first mechanical disconnecting device K3 and the second mechanical disconnecting device K4. In a specific implementation, the first switch group 11 is mainly composed of the first mechanical disconnecting device K3 and the second mechanical disconnecting device K4, the first mechanical disconnecting device K3 and the second mechanical disconnecting device K4 are respectively connected to the positive and negative poles of the battery, and serve as manual switches on the positive and negative pole circuits of the system, respectively, and the second switch group 12 is connected after the first mechanical disconnecting device K3 and the second mechanical disconnecting device K4. The first mechanical disconnecting device K3 and the second mechanical disconnecting device K4 are both the same type of switch devices, both of which can be manually operated to be turned on and off. When a system failure occurs, the first mechanical disconnecting device K3 and the second mechanical disconnecting device K4 can be manually disconnected to protect the safety of the system.

[0042] In one embodiment, referring to Figures 1 to 3 , the second switch group 12 includes a first DC fuse device K5 and a second DC fuse device K6, and the first DC fuse device K5 and the second DC fuse device K6 are connected between the first switch group 11 and the third switch group 13. In a specific implementation, the second switch group 12 is mainly composed of a first DC fuse device K5 and a second DC fuse device K6, and the first DC fuse device K5 and the second DC fuse device K6 are connected between the first switch group 11 and the second switch group 12, respectively serving as automatic switches on the positive and negative circuits of the system. The first DC fuse device K5 and the second DC fuse device K6 are both switch devices of the same type, and the first DC fuse device K5 and the second DC fuse device K6 can prevent the current on the positive and negative circuits of the system from exceeding a set range. When the current on the positive and negative circuits of the system exceeds the rated current, the fuses inside the first DC fuse device K5 and the second DC fuse device K6 will be heated and melted, thereby automatically cutting off the circuit to protect the safety of the system.

[0043] like Figure 4As shown, the present application provides an energy storage system 200, which includes: a load 201; a battery module 202, used to store electrical energy; an energy storage inverter 100, connected between the battery module 202 and the load 201, and used to configure the electrical energy stored in the battery module 202 to the load 201 for use, wherein the energy storage inverter 100 is the energy storage inverter 100 described in the above embodiment. In a specific implementation, the energy storage system 200 is composed of a load 201, a battery module 202, and an energy storage converter 100. The load 201 can be an electrical appliance. The battery module 202 is composed of a battery module 202 cluster that can store electrical energy. The energy storage converter 100 is connected between the battery module 202 and the load 201. It can control the charging and discharging process of the battery module 202, and can allocate the electrical energy stored in the battery module 202 to the load 201 for use. In the absence of a power grid, the energy storage converter 100 can directly supply power to the load 201, so that the load 201 can work normally. Since the previous specification has already made a detailed introduction to the specific structure and working principle of the energy storage converter 100, for the sake of brevity of the specification, it will not be repeated here.

[0044] The energy storage system in this embodiment adopts the energy storage converter provided by the present invention, so the system power density is higher, the system operating cost is effectively reduced, and the operation is more reliable.

[0045] like Figure 5 As shown, the present application provides a control method for an energy storage converter, the method is applied to the energy storage converter described in the above embodiment, and the method includes steps: S110-S120.

[0046] S110: Check whether the battery is faulty.

[0047] In specific implementation, the energy storage inverter is applied to the energy storage system, and the control module detects various parameters of the battery through special detection circuits (such as short-circuit detection circuit, temperature detection circuit), and compares the detected parameters with normal parameters to determine whether the battery has a fault. The battery fault may include short circuit, overheating, overvoltage, etc.

[0048] S120. If the battery fails, the DC switch group is controlled to disconnect after a first preset time delay, and the power conversion module is controlled to stop after a second preset time delay, wherein the second preset time is less than the first preset time.

[0049] In specific implementation, when the energy storage system is operating normally, the battery supplies power to the load through the energy storage converter. When the battery fails, the connection between the battery and the load needs to be disconnected in time. In the energy storage converter, the DC switch group is connected to the power conversion module, which is composed of power switch tubes. When the power conversion module is operating normally, the power switch tube is in a powered state. If the DC switch group is directly disconnected, it is considered as on-load disconnection. On-load disconnection will cause the DC switch group to bear a large impact current, which is easy to damage the DC switch group. Therefore, in this embodiment, when a battery fault is detected and a fault signal is received, the control module controls the DC switch group to disconnect after a delay of the first preset time, and controls the power conversion module to stop after a delay of the second preset time, so that all the power switch tubes in the power conversion module are closed at the second preset time, and the IGBT blocking wave is completed, wherein the second preset time is less than the first preset time, that is, the disconnection time of the DC switch group is later than the stopping of the power conversion module. Specifically, the process of the control module controlling the power conversion module to stop is usually in microseconds, and the process of controlling the DC switch group to disconnect is usually in milliseconds, and the power conversion module stops first and then the DC switch group disconnects. Since the power conversion module has stopped before the DC switch group is disconnected, the DC switch group can be effectively prevented from being disconnected under load.

[0050] In one embodiment, if Figure 6 As shown, the method further includes steps: S130-S150.

[0051] S130, if a power-on command is received, detecting the DC bus voltage of the power conversion module;

[0052] In specific implementation, if the DC bus voltage of the power conversion module differs too much from the output voltage of the battery, the DC switch group is directly closed and turned on, and the impact current of the DC switch group is too high and it is easy to be damaged. Therefore, it is necessary to ensure that the DC bus voltage and the output voltage of the battery do not differ too much. Therefore, after the system receives the power-on command, the system first performs a self-check, and the control module confirms that the corresponding DC switch group is in the disconnected state. The control module detects the DC bus voltage in the power conversion module through the corresponding detection circuit.

[0053] S140, determining whether the DC bus voltage of the power conversion module reaches a preset voltage.

[0054] In a specific implementation, after the control module detects the DC bus voltage of the power conversion module, it compares the DC bus voltage of the power conversion module with a preset voltage. The preset voltage is usually set close to the output voltage of the battery. By comparing the DC bus voltage with the preset voltage, it can be determined whether the DC bus voltage of the power conversion module has reached a level that can directly control the DC switch group to close and conduct.

[0055] S150: If the DC bus voltage of the power conversion module reaches the preset voltage, the DC switch group is controlled to be turned on.

[0056] In a specific implementation, the preset voltage is close to the output voltage of the battery. After the DC bus voltage of the power conversion module reaches the preset voltage, it means that the DC bus voltage is close to the output voltage of the battery, and the condition for directly controlling the DC switch group to be closed and turned on is met. At this time, the control module directly controls the corresponding DC switch group to be closed and turned on. When the DC switch group is turned on, it will not be subject to too much current shock, thereby ensuring the safety of the DC switch group.

[0057] The control method of the energy storage inverter of the present application detects whether a battery fault occurs. When a battery fault occurs, the DC switch group is controlled to disconnect after a delay of a first preset time, and the power conversion module is controlled to stop after a delay of a second preset time. The second preset time is less than the first preset time, so that the power conversion module has stopped before the DC switch group is disconnected, effectively avoiding the disconnection of the DC switch group under load, and improving the reliability of the energy storage system.

[0058] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An energy storage converter, used to be connected between a battery and a load, characterized in that: include: A DC power distribution module, comprising a plurality of DC switch groups of different types, wherein the DC switch groups are used to switch on and off the power output of the battery; A power conversion module, connected to the DC switch group, for performing power conversion on the electric energy output by the battery to provide it to the load; The control module is connected to the DC switch group and the power conversion module, and is used to control the on and off of the DC switch group, and control the power conversion module to run or stop.

2. The energy storage converter according to claim 1, characterized in that: The multiple different types of DC switch groups include a first switch group, a second switch group and a third switch group connected in sequence, the first switch group is connected to the battery, the third switch group is connected to the power conversion module and the control module, wherein the control module is used to control the on and off of the third switch group.

3. The energy storage converter according to claim 2, characterized in that: The DC power distribution module further includes a DC soft-start unit, which is connected to the third switch group and the power conversion module, wherein the DC soft-start unit is used to soft-start the on and off of the third switch group.

4. The energy storage converter according to claim 3, characterized in that: The third switch group includes a first controlled breaking device and a second controlled breaking device, wherein the first controlled breaking device and the second controlled breaking device are both connected to the power conversion module and the control module, and at least one of the first controlled breaking device and the second controlled breaking device is connected to the DC soft start unit.

5. The energy storage converter according to claim 4, characterized in that: The control module includes a control module and a drive module, the control module is connected to the drive module and the power conversion module, and the drive module is connected to the first controlled breaking device and the second controlled breaking device, wherein the control module is used to drive the first controlled breaking device and the second controlled breaking device to be turned on and off through the drive module, and to control the power conversion module to run or stop.

6. The energy storage converter according to claim 5, characterized in that: The control module includes a main control unit and a sampling control unit, and the driving module includes a first driving unit and a second driving unit, wherein the first driving unit is connected to the main control unit and the first controlled breaking device, the sampling control unit is connected to the main control unit, the second driving unit and the power conversion module, and the second driving unit is connected to the second controlled breaking device, wherein the main control unit is used to drive the first controlled breaking device to be turned on and off through the first driving unit, and the sampling control unit is used to drive the second controlled breaking device to be turned on and off through the second driving unit, and control the power conversion module to run or stop.

7. The energy storage converter according to claim 5, characterized in that: The control module includes a main control unit and a sampling control unit, the driving module includes a first driving unit and a second driving unit, the main control unit is connected to the first driving unit and the second driving unit, the first controlled breaking device and the second controlled breaking device are respectively connected to the first driving unit and the second driving unit, the sampling control unit is connected to the main control unit and the power conversion module, wherein the main control unit is used to drive the first controlled breaking device and the second controlled breaking device to be turned on and off through the first driving unit and the second driving unit respectively, and the sampling control unit is used to control the power conversion module to run or stop.

8. The energy storage converter according to any one of claims 2 to 7, characterized in that: The first switch group includes a first mechanical disconnecting device and a second mechanical disconnecting device, wherein the first mechanical disconnecting device and the second mechanical disconnecting device are respectively connected to the positive and negative poles of the battery, and the second switch group is connected after the first mechanical disconnecting device and the second mechanical disconnecting device.

9. The energy storage converter according to any one of claims 2 to 7, characterized in that: The second switch group includes a first DC fuse device and a second DC fuse device, and the first DC fuse device and the second DC fuse device are connected between the first switch group and the third switch group.

10. A control method for an energy storage converter, applied to the energy storage converter according to any one of claims 1 to 9, characterized in that: The method comprises: Check if the battery is faulty; If the battery fails, the DC switch group is controlled to disconnect after a first preset time delay, and the power conversion module is controlled to stop after a second preset time delay, wherein the second preset time is less than the first preset time.

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