Power supply conversion circuit and micro-grid and energy storage system for uninterrupted external power supply

Abstract

The application provides a power supply conversion circuit for uninterrupted external power supply and a micro-grid and energy storage system. The power supply conversion circuit is used in the micro-grid and energy storage system. The power supply conversion circuit comprises a switching module, a first power supply conversion circuit, a second power supply conversion circuit and a redundant power supply circuit. When the power grid is powered off, the second power supply conversion circuit takes power from a battery module of the micro-grid and energy storage system, and supplies power to a control management module through the redundant power supply circuit, thereby realizing uninterrupted power supply of the control management module. The control management module can perform black start of the energy storage system and output corresponding power supply control signals to an energy storage converter and output switch control signals to the switching module, so as to control the battery module to discharge through the energy storage converter, complete the black start action function, thereby driving start of each load in the system, and finally restore power of the entire system. Moreover, the UPS installation structure and the UPS equipment do not need to be set and introduced, and the design cost and the maintenance cost are reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of micro-grid and energy storage, and particularly relates to a power supply conversion circuit for uninterrupted power supply and a micro-grid and energy storage system. BACKGROUND

[0002] The micro-grid and energy storage system is composed of a PCS (Power Conversion System, energy storage converter), a battery module, an upper computer, a fire-fighting system, a cooling system and the like. The battery module is connected with the power grid through a switching module and the energy storage converter. When the switching module is turned on, the battery module is charged or discharged by the energy storage converter. In the process of discharging, the battery discharges and supplies power to the load and / or the power grid through the energy storage converter to perform frequency regulation and peak shaving, etc. In the process of charging, the battery is charged through the energy storage converter.

[0003] In the off-grid state, the micro-grid and energy storage system needs to perform black start operation. The black start refers to that after the whole system is shut down due to a fault, the system is completely powered off and is in a full "black" state, does not rely on other power networks for help, and is started by the generator set with self-starting capability in the system to drive the generator set without self-starting capability, gradually expands the system recovery range, and finally realizes the recovery of the whole system.

[0004] The traditional black start mode is to supply power to the control part of the energy storage system by using an UPS (Uninterrupted Power Supply) to make the control switch conductive to realize black start. However, the power of the UPS scheme is large and the cost is high, and there is a service life limit, which increases the fault points and causes large black start cost and equipment maintenance cost. SUMMARY

[0005] The application aims to provide a power supply conversion circuit for uninterrupted power supply, and aims to solve the problems of large power and high cost in the traditional black start mode.

[0006] The first aspect of the embodiment of the application provides a power supply conversion circuit for uninterrupted power supply, which is used in a micro-grid and energy storage system. The micro-grid and energy storage system includes a battery module, a control management module, a photovoltaic module, a wind power module and an energy storage converter. The energy storage converter is connected with the power grid, the photovoltaic module, the wind power module, the battery module and the control management module respectively. The control management module is used to output a power supply control signal to control the energy storage converter to perform bidirectional power conversion output and / or on-off after power-on. The power grid is also connected with a load.

[0007] The power supply conversion circuit for uninterrupted power supply includes:

[0008] A switch module is connected between the energy storage converter and the battery module, and the switch module is triggered to be turned on or turned off by a switch control signal output by the control management module;

[0009] A first power conversion circuit is connected to the AC end of the power grid and the energy storage converter, and is configured to convert the AC power source of the power grid or the energy storage converter into a first DC power source;

[0010] A second power conversion circuit is connected to the power supply end of the battery module, and is configured to convert the DC power source of the battery module into a second DC power source, and the first DC power source and the second DC power source are the same;

[0011] A redundant power supply circuit is connected to the first power conversion circuit, the second power conversion circuit, and the control management module, and is configured to convert the first DC power source or the second DC power source into a power supply source, and provide the power supply source for the control management module, wherein the power supply priority of the first power conversion circuit is higher than that of the second power conversion circuit.

[0012] In one embodiment, the switch module includes:

[0013] A first switch circuit is connected between the energy storage converter and the battery module, and is triggered to be turned on or turned off by a received switch signal;

[0014] A switch control circuit is connected to the redundant power supply circuit, the first switch circuit, and the control management module, and is configured to obtain the power supply source through the redundant power supply circuit, and output the switch signal based on the switch control signal output by the control management module.

[0015] In one embodiment, the energy storage converter is provided with a controller, and the controller is configured to receive the power control signal and control the energy storage converter to perform bidirectional power conversion output and / or on-off when powered on;

[0016] The redundant power supply circuit is also connected to the power supply end of the controller of the energy storage converter and provides the power supply source.

[0017] In one embodiment, the first power conversion circuit and the second power conversion circuit are switch power supply circuits.

[0018] In one embodiment, the redundant power supply circuit includes a switch power supply circuit;

[0019] and / or includes a power supply switching circuit, and the power supply switching circuit includes:

[0020] a second switch circuit, disposed between the first input terminal and the output terminal of the power supply switching circuit, for connecting a first path between the first input terminal and the output terminal when the first DC power supply is inputted into the first input terminal, so that the first DC power supply outputs the power supply through the output terminal; and for disconnecting the first path when the first DC power supply is not inputted into the first input terminal;

[0021] a third switch circuit, disposed between the second input terminal and the output terminal of the power supply switching circuit, and a control terminal of the third switch circuit being connected to the first input terminal, for disconnecting a second path between the second input terminal and the output terminal when the first DC power supply is inputted into the first input terminal; and for connecting the second path when the first DC power supply is not inputted into the first input terminal and the second DC power supply is inputted into the second input terminal, so that the second DC power supply outputs the power supply through the output terminal.

[0022] A second aspect of the embodiment of the present application provides a micro-grid and energy storage system, comprising a battery module, a control management module, a photovoltaic module, a wind power module, an energy storage converter and the uninterrupted power supply conversion circuit as described above, the energy storage converter is connected with a power grid, the photovoltaic module, the wind power module, the uninterrupted power supply conversion circuit and the control management module respectively, the uninterrupted power supply conversion circuit is further connected with the battery module, the control management module and the power grid, and the power grid is further connected with a load;

[0023] The uninterrupted power supply conversion circuit is used for acquiring power supply through the battery module or the power grid and converting the power supply into a power supply;

[0024] The control management module is used for outputting a switch control signal to control on-off of a switch module of the uninterrupted power supply conversion circuit after power-on, and outputting a power supply control signal to control the energy storage converter to perform bidirectional power conversion output and / or on-off.

[0025] In one of the embodiments, the control management module comprises:

[0026] a battery management module, connected with the uninterrupted power supply conversion circuit and the battery module, and used for acquiring power of the battery module and performing battery management when power-on;

[0027] The upper computer is connected with the uninterrupted power supply conversion circuit, the battery management module, the energy storage converter and the switch module of the uninterrupted power supply conversion circuit, respectively, and is used to acquire power grid information through the energy storage converter and battery module power information through the battery management module when powered on, and output the switch control signal to control the switch module on-off and output the power control signal to control the energy storage converter to output and / or on-off bidirectional power conversion.

[0028] In one embodiment, the upper computer is specifically used for:

[0029] When receiving the power grid information representing power-off of the power grid, the battery module power information is acquired.

[0030] When the battery module power is greater than a preset value, the black start mode is switched to, the switch signal is output to control the switch module to be turned on, and the power control signal is output to control the energy storage converter to convert the direct current power of the battery module into alternating current power and output to the power grid and load, or control the energy storage converter to output the power of the photovoltaic module and / or wind power module to the power grid and / or load.

[0031] When the battery module power is less than a preset value, the power control signal is output to control the energy storage converter to stop working, or when the battery module power is less than a preset value, the energy storage converter is controlled to output the power of the photovoltaic module and / or wind power module to the power grid and / or load.

[0032] When receiving the power grid information representing that the load power of the load is less than a preset load power, the energy storage converter is controlled to output the power of the photovoltaic module and / or wind power module to the power grid and / or load.

[0033] When receiving the power grid information representing initial grid connection or restored grid connection of the power grid, the power control signal is output to control the energy storage converter to convert the alternating current power of the power grid into direct current power and output to the battery module through the switch module.

[0034] In one embodiment, the energy storage converter is a three-phase four-wire energy storage converter.

[0035] Alternatively, the energy storage converter includes a transformer, and the transformer includes a first phase line, a second phase line, a third phase line and a neutral line.

[0036] In one embodiment, the control management module further includes:

[0037] A smoke sensing system connected with the uninterrupted power supply conversion circuit, used for smoke sensing protection when powered on.

[0038] A fire extinguishing system connected with the uninterrupted power supply conversion circuit, used for fire extinguishing protection when powered on.

[0039] A water immersion system connected with the uninterrupted power supply conversion circuit, used for water immersion protection when powered on.

[0040] A temperature system connected with the uninterrupted power supply conversion circuit, used for temperature detection when powered on.

[0041] A combustible gas detection system connected with the uninterrupted power supply conversion circuit, used for combustible gas detection when powered on.

[0042] Compared with the prior art, the power supply conversion circuit comprises a switch module, a first power supply conversion circuit, a second power supply conversion circuit and a redundant power supply circuit, the power supply priority of the first power supply conversion circuit is higher than that of the second power supply conversion circuit when the power grid is normally connected, the first power supply conversion circuit takes power from the power grid and supplies power to the control management module of the micro-grid and the energy storage system through the redundant power supply circuit, the second power supply conversion circuit takes power from the battery module of the micro-grid and the energy storage system when the power grid is powered off, and supplies power to the control management module through the redundant power supply circuit, thereby realizing uninterrupted power supply of the control management module, the control management module can perform black start of the energy storage system and output corresponding power control signals to the energy storage converter and output switch control signals to the switch module, so as to control the battery module to discharge through the energy storage converter, complete the black start function, thereby driving the start of each load in the system, finally restore the power of the entire system, and without setting the UPS installation structure and introducing the UPS equipment, the design cost and the maintenance cost are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 A first structure diagram of the micro-grid and the energy storage system is provided for the embodiment of the present application.

[0044] Figure 2 A second structure diagram of the micro-grid and the energy storage system is provided for the embodiment of the present application.

[0045] Figure 3 A structure diagram of the redundant power supply circuit is provided for the embodiment of the present application.

[0046] Figure 4 A circuit structure diagram of the redundant power supply circuit is provided for the embodiment of the present application.

[0047] Figure 5A third structural schematic diagram of a micro-grid and energy storage system according to an embodiment of the present application is provided;

[0048] Figure 6 A fourth structural schematic diagram of a micro-grid and energy storage system according to an embodiment of the present application is provided. DETAILED DESCRIPTION

[0049] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clearly, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0050] In addition, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0051] A first aspect of the embodiment of the present application proposes an uninterrupted power supply conversion circuit 10 for a micro-grid and energy storage system 1, as shown in Figure 1 As shown, the micro-grid and energy storage system 1 includes a battery module 50, a control management module 60, a photovoltaic module 30, a wind power module 40 and an energy storage converter 20, the energy storage converter 20 is connected with the power grid 2, the photovoltaic module 30, the wind power module 40, the battery module 50 and the control management module 60, and the control management module 60 is used to output a power control signal to control the energy storage converter 20 to perform bidirectional power conversion output and / or on-off after power-on.

[0052] In the embodiment, the control management module 60 performs control management work of the energy storage converter 20 and the battery module 50, and through output of corresponding power control signals, the energy storage converter 20 can perform conversion work from alternating current power to direct current power and on-off control, and can also perform conversion work from direct current power to alternating current power and on-off control.

[0053] The micro-grid and energy storage system 1 can work in a state of grid 2 grid connection or grid 2 power failure. When the grid 2 is connected, that is, the grid 2 is powered, the grid 2 outputs power to the load 3 connected to the grid 2, and on the other hand, the grid 2 outputs alternating current power to the energy storage converter 20, and the energy storage converter 20 performs AC-DC work under the control of the power control signal, converts the alternating current power into charging power, and outputs the charging power to the battery module 50 for charging.

[0054] When the power grid 2 is powered off, the control management module 60 keeps power supply through the uninterrupted power supply circuit, thereby automatically performing black start control through the control management module issuing instructions and outputting a power supply control signal to control the energy storage converter 20 to perform battery discharge work to output an alternating current power supply to the power grid 2 and each load 3 or generator connected to the power grid 2, so as to realize self-start of the overall system and external power supply of the micro-grid.

[0055] Meanwhile, under the normal or powered-off state of the power grid 2, the photovoltaic module 30 and / or the wind power module 40 can also charge the battery module 50 through the energy storage converter 20 or provide an alternating current power supply to the power grid 2 and the load 3, or when the load power supply output by the photovoltaic module 30 and / or the wind power module 40 is insufficient, the battery module 50 discharges to the photovoltaic module 30 and the wind power module 40 or discharges to the load 3 through the energy storage converter 20.

[0056] The battery module 50 can include one or more groups of battery packs connected in series or in parallel, and the specific structure is not limited.

[0057] The control management module 60 can include a corresponding battery management module 62, an upper computer 61 and other modules.

[0058] In order to realize reliable power supply of the control management module 60 and ensure that it can perform corresponding power supply control work under different states of the power grid 2, in the embodiment, the micro-grid and energy storage system 1 further includes an uninterrupted power supply conversion circuit 10, and the uninterrupted power supply conversion circuit 10 is connected with the energy storage converter 20, the power grid 2, the battery module 50 and the control management module 60, respectively. Figure 1 As shown in the figure, the uninterrupted power supply conversion circuit 10 includes:

[0059] A switch module 11 connected between the energy storage converter 20 and the battery module 50, the switch module 11 is triggered to be turned on or turned off by a switch control signal output by the control management module 60;

[0060] A first power supply conversion circuit 12 connected with the power grid 2 and the alternating current end of the energy storage converter 20, the first power supply conversion circuit 12 is used for converting the alternating current power supply of the power grid 2 or the energy storage converter 20 into a first direct current power supply;

[0061] A second power supply conversion circuit 13 connected with the power supply end of the battery module 50, the second power supply conversion circuit 13 is used for converting the direct current power supply of the battery module 50 into a second direct current power supply, and the first direct current power supply and the second direct current power supply are the same;

[0062] The redundant power supply circuit 14 is connected with the first power conversion circuit 12, the second power conversion circuit 13 and the control management module 60 respectively, and is used for converting the first direct current power or the second direct current power into a power supply and providing the power supply for the control management module 60, wherein the power supply priority of the first power conversion circuit 12 is greater than that of the second power conversion circuit 13.

[0063] In the embodiment, in the grid-connected state of the power grid 2, the energy storage converter 20 obtains power from the power grid 2, the first power conversion circuit 12 obtains power from the power grid 2 and converts the alternating current power of the power grid 2 into the first direct current power, and due to the power supply priority of the first power conversion circuit 12 being greater than that of the second power conversion circuit 13, the first direct current power is output to the control management module 60 through the redundant power supply circuit 14, the control management module 60 first outputs the switch control signal to the switch module 11 to control the switch module 11 to be turned on, and then outputs the power supply control signal to the energy storage converter 20 to control the energy storage converter 20 to convert the alternating current power of the power grid 2 into the power supply, and the charging power is used to charge the battery module 50 through the switch module 11.

[0064] When the power grid 2 is powered off, the switch module 11 may be disconnected, at this time, the first power conversion circuit 12 has no power input, the second power conversion circuit 13 obtains the direct current power through the battery module 50 and converts the direct current power into the second direct current power, the second direct current power has the same voltage and current as the first direct current power, the second direct current power is output to the control management module 60 through the redundant power supply circuit 14 to realize uninterrupted power supply for the control management module 60, the control management module 60 is powered on, can first output the switch control signal to the switch module 11 to control the switch module 11 to be turned on or maintain the turn-on, and then output the power supply control signal to the energy storage converter 20, the direct current power of the battery module 50 is output to the direct current end of the energy storage converter 20 through the switch module 11, the energy storage converter 20 works in the direct current-to-alternating current mode and outputs the alternating current power to the power grid 2, which ensures that the switch module 11 will not be disconnected due to temporary power loss, ensures that the entire control system obtains power, and at the same time can drive each load 3 in the system to start, and finally restores the power of the entire system.

[0065] After the power grid 2 obtains power through the energy storage converter 20, the first power conversion circuit 12 obtains power again and outputs the first direct current power to the redundant power supply circuit 14, based on the power supply priority, the power input of the redundant power supply circuit 14 is switched to the first direct current power, and the first direct current power is converted into the power supply to the control management module 60.

[0066] and after the power grid 2 is restored, the first power conversion circuit 12 directly takes power through the power grid 2 and outputs the first direct current power to the redundant power supply circuit 14. Based on the power supply priority, the power supply input of the redundant power supply circuit 14 is switched to the first direct current power, and the first direct current power is converted into a power supply to the control management module 60.

[0067] By setting the first power conversion circuit 12, the second power conversion circuit 13 and the redundant power supply circuit 14, it can be ensured that the micro-grid and energy storage system 1 can maintain the power taking state in different working states, and the power management and control of the micro-grid and energy storage system 1 can be maintained, thereby improving the working reliability and stability of the micro-grid and energy storage system 1.

[0068] And without setting UPS, the design cost or maintenance cost of the micro-current energy storage system can be reduced. The first power conversion circuit 12, the second power conversion circuit 13 and the redundant power supply circuit 14 are used for power conversion, without additional power consumption, thereby reducing the system power consumption.

[0069] In addition, the uninterrupted power supply conversion circuit 10 is used for uninterrupted power supply, which can ensure that the data acquisition, safety and fire-fighting system can work normally in the case of power grid 2 power failure, report and quickly eliminate safety hazards, and ensure the safety of the system.

[0070] Among them, the first power conversion circuit 12, the second power conversion circuit 13 and the redundant power supply circuit 14 have some basic auxiliary switching devices, and the switching of the first power conversion circuit 12 and the second power conversion circuit 13 can be controlled by human to realize the corresponding on-off control.

[0071] Among them, the switching module 11 can use separate switching devices or add corresponding driving control devices. In an optional embodiment, as shown in Figure 2 The switching module 11 includes:

[0072] The first switching circuit 111 is connected between the energy storage converter 20 and the battery module 50, and the first switching circuit 111 is triggered to conduct or turn off by the received switching signal;

[0073] The switching control circuit 112 is connected with the redundant power supply circuit 14, the first switching circuit 111 and the control management module 60 respectively. The switching control circuit 112 is used to obtain the power supply through the redundant power supply circuit 14, and output the switching signal based on the switching control signal output by the control management module 60.

[0074] In this embodiment, since a large voltage is applied between the energy storage converter 20 and the battery module 50, the switch control signal output by the control management module 60 is a small voltage. In order to achieve control operation from small voltage to large voltage, the switch control circuit 112 is connected to the first switch circuit 111 and the control management module 60. The switch control circuit 112 can be used for signal amplification or conversion of the switch control signal.

[0075] When the power grid 2 is connected to the grid or disconnected, the redundant power supply circuit 14 can obtain power from the first power conversion circuit 12 or the second power conversion circuit 13. The power supply is synchronously output to the control management module 60 and the switch control circuit 112 to achieve uninterrupted power supply to the control management module 60 and the switch control circuit 112. Driven by the power supply, the switch control circuit 112 outputs a switch signal to the first switch circuit 111 based on the received switch control signal, thereby controlling the first switch circuit 111 to be turned on or off.

[0076] The first switching circuit 111 can be a controllable switch such as a relay, circuit breaker, electronic switch, or semiconductor, and the switching control circuit 112 can be a coil power supply circuit, a signal amplification circuit, etc.

[0077] In an optional embodiment, the first switching circuit 111 and the switching control circuit 112 are centrally located in the high-voltage box, and the energy storage converter 20 performs charging and discharging operations between the high-voltage box and the battery module 50.

[0078] In one embodiment, the energy storage converter 20 includes a controller and a bidirectional power conversion circuit. The bidirectional power conversion circuit is used to perform bidirectional AC-DC conversion. The controller is used to receive power control signals when powered on and control the bidirectional power conversion circuit of the energy storage converter 20 to perform bidirectional power conversion output and / or switching on and off.

[0079] Correspondingly, in order to ensure the controller powers on normally and the energy storage converter 20 operates normally, such as Figure 2 As shown, the redundant power supply circuit 14 is also connected to the power supply terminal of the controller of the energy storage converter 20 and provides power supply.

[0080] When the power grid 2 is connected to the grid or is disconnected, the redundant power supply circuit 14 can obtain power from the first power conversion circuit 12 or the second power conversion circuit 13. The power supply is synchronously output to the controllers of the control management module 60, the switch control circuit 112 and the energy storage converter 20, so as to realize uninterrupted power supply to the controllers of the control management module 60, the switch control circuit 112 and the energy storage converter 20. Under the drive of the power supply, the controller controls the bidirectional power conversion circuit to perform bidirectional power conversion based on the received power control signal, and / or controls the bidirectional power conversion circuit to be turned on or off.

[0081] In the first power conversion circuit 12 and the second power conversion circuit 13, a corresponding power supply circuit can be used. In one embodiment, the first power conversion circuit 12 and the second power conversion circuit 13 are switching power supply circuits, which include an input rectifier filter circuit, an inverter circuit, a transformer, an output rectifier filter circuit, etc., and can convert AC to DC and also convert DC to DC.

[0082] Correspondingly, in one embodiment, the redundant power supply circuit 14 includes a switching power supply circuit.

[0083] And / or, the redundant power supply circuit 14 includes a power supply switching circuit 141.

[0084] When the redundant power supply circuit 14 includes a switching power supply circuit, a corresponding sampling circuit can be provided in the switching power supply circuit. The sampling circuit uses the input state of the first power conversion circuit 12 and the second power conversion circuit 13, and a control unit in the switching power supply circuit sets the power supply priority according to the sampling signal, and the first DC power supply of the first power conversion circuit 12 is prioritized.

[0085] When the redundant power supply circuit 14 includes a power supply switching circuit 141, the power supply switching circuit 141 is provided with a corresponding switching unit. The switching unit is turned on or off according to the input of the first DC power supply and the second DC power supply, and connects the input end and the output end, thereby forming a corresponding power supply priority.

[0086] When the redundant power supply circuit 14 includes a switching power supply circuit and a power supply switching circuit 141, the switching power supply circuit can be connected to the input end or the output end of the power supply switching circuit 141. The switching power supply circuit is used for power conversion, and the power supply switching circuit 141 is provided with a corresponding switching unit. The switching unit is turned on or off according to the input of the first DC power supply and the second DC power supply, and connects the input end and the output end, thereby forming a corresponding power supply priority.

[0087] In an optional embodiment, as shown in Figure 3 The power supply switching circuit 141 includes:

[0088] The second switching circuit 1411 is arranged between the first input end and the output end of the power supply switching circuit 141. When the first DC power supply is input to the first input end, the first switching circuit 1411 connects the first path between the first input end and the output end, so that the first DC power supply is output through the output end as a power supply; and when the first DC power supply is not input to the first input end, the first switching circuit 1411 disconnects the first path.

[0089] The third switch circuit 1412 is arranged between the second input terminal and the output terminal of the power supply switching circuit 141, and the control terminal of the third switch circuit 1412 is connected to the first input terminal. When the first DC power is input to the first input terminal, the second switch circuit 1411 is turned on, and the third switch circuit 1412 is turned off, so that the first DC power is output through the second switch circuit 1411 and output as the power supply to the control management module 60, the switch control circuit 112 and the controller.

[0090] In the embodiment, it is assumed that the redundant power supply circuit 14 includes the power supply switching circuit 141. When the first power conversion circuit 12 outputs the first DC power to the second switch circuit 1411, the second switch circuit 1411 is triggered to be turned on, and the third switch circuit 1412 is triggered to be turned off. The first DC power is output through the second switch circuit 1411 and output as the power supply to the control management module 60, the switch control circuit 112 and the controller.

[0091] When the first power conversion circuit 12 does not output the first DC power to the second switch circuit 1411, the second power conversion circuit 13 outputs the second DC power to the third switch circuit 1412. The second switch circuit 1411 is triggered to be turned off, and the third switch circuit 1412 is triggered to be turned on. The second DC power is output through the third switch circuit 1412 and output as the power supply to the control management module 60, the switch control circuit 112 and the controller, so as to realize uninterrupted power supply to the control management module 60, the switch control circuit 112 and the controller of the energy storage converter 20.

[0092] The second switch circuit 1411 and the third switch circuit 1412 can adopt corresponding types of switching devices, for example Figure 4 As shown in an optional embodiment, the second switch circuit 1411 includes a first resistor R1, a second resistor R2, a third resistor R3, a first electronic switch tube Q1 and a second electronic switch tube Q2. The first terminal of the first resistor R1 and the first terminal of the second electronic switch tube Q2 are connected to form the input terminal of the second switch circuit 1411. The second terminal of the first resistor R1, the first terminal of the second resistor R2 and the control terminal of the first electronic switch tube Q1 are connected. The second terminal of the second resistor R2 and the first terminal of the first electronic switch tube Q1 are connected and grounded. The output terminal of the first electronic switch tube Q1 and the first terminal of the third resistor R3 are connected. The second terminal of the third resistor R3 and the control terminal of the second electronic switch tube Q2 are connected. The second terminal of the second electronic switch tube Q2 forms the output terminal of the second switch circuit 1411.

[0093] The third switch circuit 1412 comprises a fourth resistor R4, a fifth resistor R5 and a third electronic switch tube Q3. The first end of the fourth resistor R4 constitutes the control end of the third switch circuit 1412. The second end of the fourth resistor R4, the first end of the fifth resistor R5 and the control end of the third electronic switch tube Q3 are connected. The first end of the fifth resistor R5 is grounded. The first end of the third electronic switch tube Q3 constitutes the input end of the third switch circuit 1412. The second end of the third electronic switch tube Q3 constitutes the output end of the third switch circuit 1412.

[0094] When the first power conversion circuit 12 outputs the first direct current power to the second switch circuit 1411 and the third switch circuit 1412, the first electronic switch tube Q1 is turned on, and outputs a low level to the second electronic switch tube Q2. The second electronic switch tube Q2 is triggered to be turned on. The third electronic switch tube Q3 receives a high level and is triggered to be turned off. The first direct current power is output through the second electronic switch tube Q2, and is output as a power supply to the control management module 60, the switch control circuit 112 and the controller.

[0095] When the first power conversion circuit 12 does not output the first direct current power to the second switch circuit 1411, the second power conversion circuit 13 outputs the second direct current power to the third switch circuit 1412. The first electronic switch tube Q1 and the second electronic switch tube Q2 are triggered to be turned off. The third electronic switch tube Q3 receives a low level and is triggered to be turned on. The second direct current power is output through the third electronic switch tube, and is output as a power supply to the control management module 60, the switch control circuit 112 and the controller of the energy storage converter 20, thereby realizing uninterrupted power supply to the control management module 60, the switch control circuit 112 and the controller of the energy storage converter 20.

[0096] The first electronic switch tube Q1 is an NMOS tube. The second electronic switch tube Q2 and the third electronic switch tube Q3 are PNP triodes.

[0097] Compared with the prior art, the embodiment of the present application has the beneficial effects that: the uninterrupted power supply conversion circuit 10 includes a switch module 11, a first power supply conversion circuit 12, a second power supply conversion circuit 13, and a redundant power supply circuit 14. When the power grid 2 is normally connected, the power supply priority of the first power supply conversion circuit 12 is higher than that of the second power supply conversion circuit 13. The first power supply conversion circuit 12 obtains power from the power grid 2 and supplies power to the control management module 60 of the micro-grid and energy storage system 1 through the redundant power supply circuit 14. When the power grid 2 is powered off, the second power supply conversion circuit 13 obtains power from the battery module 50 of the micro-grid and energy storage system 1 and supplies power to the control management module 60 through the redundant power supply circuit 14. The control management module 60 can perform black start and output corresponding power control signals to the energy storage converter 20 and output switch control signals to the switch module 11 to control the battery module 50 to discharge through the energy storage converter 20, thereby driving each load 3 in the system to start, and ultimately restoring the power of the entire system. Moreover, there is no need to set up a UPS structure, thereby reducing the design cost and maintenance cost.

[0098] The present application also provides a micro-grid and energy storage system 1, which comprises a battery module 50, a control management module 60, a photovoltaic module 30, a wind power module 40, an energy storage converter 20, and an uninterrupted power supply conversion circuit 10. The specific structure of the uninterrupted power supply conversion circuit 10 is referred to the above embodiment. Since the micro-grid and energy storage system 1 adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described here.

[0099] The energy storage converter 20 is connected with the power grid 2, the photovoltaic module 30, the wind power module 40, the uninterrupted power supply conversion circuit 10, and the control management module 60. The uninterrupted power supply conversion circuit 10 is also connected with the battery module 50, the control management module 60, and the power grid 2. The power grid 2 is also connected with the load 3.

[0100] The uninterrupted power supply conversion circuit 10 is used to obtain power from the battery module 50 or the power grid 2 and convert it into a power supply to realize uninterrupted power supply to the control management module 60.

[0101] The control management module 60 is used to output a switch control signal to control the on-off of the switch module 11 of the uninterrupted power supply conversion circuit 10 after power-on, and output a power control signal to control the energy storage converter 20 to perform bidirectional power conversion output and / or on-off.

[0102] In this embodiment, in order to realize reliable power supply of the control management module 60 and ensure that it can perform corresponding power control work in different states of the power grid 2, the micro-grid and energy storage system 1 further comprises an uninterrupted power supply conversion circuit 10, which is connected with the energy storage converter 20, the power grid 2, the battery module 50 and the control management module 60 respectively.

[0103] The control management module 60 performs control management work of the uninterrupted power supply conversion circuit 10, the energy storage converter 20 and the battery module 50, and controls the on-off of the switch module 11 of the uninterrupted power supply conversion circuit 10 and the conversion of the energy storage converter 20 from AC power to DC power and vice versa through output of corresponding switch control signals and power control signals.

[0104] The micro-grid and energy storage system 1 can work in the state of grid connection of the power grid 2 or power failure of the power grid 2. When the power grid 2 is connected, the power grid 2 outputs power to the load 3 connected to the power grid 2, and outputs AC power to the energy storage converter 20. The uninterrupted power supply conversion circuit 10 takes power from the power grid 2. The control management module 60 obtains power supply through the first power conversion circuit 12 and the redundant power supply circuit 14 in the uninterrupted power supply conversion circuit 10. The control management module 60 first outputs a switch control signal to the switch module 11 in the uninterrupted power supply conversion circuit 10 to control the switch module 11 to be turned on, and then outputs a power control signal to the energy storage converter 20. The energy storage converter 20 converts AC power to DC power under the control of the power control signal, and converts the AC power to a charging power. The charging power is output to the battery module 50 through the switch module 11 for charging.

[0105] When the power grid 2 is powered off, the uninterrupted power supply conversion circuit 10 obtains DC power from the battery module 50. The control management module 60 obtains power supply through the second power conversion circuit 13 and the redundant power supply circuit 14 in the uninterrupted power supply conversion circuit 10. The control management module 60 can first output a switch control signal to the switch module 11 in the uninterrupted power supply conversion circuit 10 to control the switch module 11 to be turned on or maintained. The control management module 60 is powered on and performs black start control. The control management module 60 outputs a power control signal to control the energy storage converter 20 to perform battery discharge work to output AC power to the power grid 2 and each load 3 or generator connected with the power grid 2, so as to realize self-start of the whole system. The switch module 11 is ensured not to be turned off due to temporary power failure, the whole control system is ensured to take power, each load 3 in the system is ensured to be started, and finally the power of the whole system is restored.

[0106] Meanwhile, in the normal or outage state of the power grid 2, the photovoltaic module 30 and / or the wind power module 40 can also charge the battery module 50 or provide AC power to the power grid 2 and the load 3 through the energy storage converter 20, or when the load power output by the photovoltaic module 30 and / or the wind power module 40 is insufficient, the battery module 50 discharges to the photovoltaic module 30 and the wind power module 40 or discharges to the power grid 2 and / or the load through the energy storage converter 20.

[0107] The energy storage converter 20 can adopt a controller and a bidirectional power conversion circuit. Since in the outage state of the power grid 2, i.e., the off-grid state, the AC power output needs to meet the transmission of the power grid 2, corresponding to the form of the power grid 2, in one embodiment, the energy storage converter 20 is a three-phase four-wire energy storage converter 20.

[0108] Alternatively, the energy storage converter 20 includes a transformer, and the transformer includes a first phase line, a second phase line, a third phase line, and a neutral line. The three-phase four-wire energy storage function is realized by using the neutral line mode of the transformer.

[0109] The battery module 50 can include one or more groups of battery packs connected in series and / or in parallel, and the specific structure is not limited.

[0110] The control management module 60 can include corresponding battery management module 62, host computer 61 and other modules. In one embodiment, as shown in Figure 5 The control management module 60 includes:

[0111] The battery management module 62 is connected with the uninterrupted power supply conversion circuit 10 and the battery module 50. The battery management module 62 is used to obtain the power of the battery module 50 and perform battery management when powered on.

[0112] The host computer 61 is connected with the redundant power supply circuit 14 of the uninterrupted power supply conversion circuit 10, the battery management module 62, the energy storage converter 20, and the switch module 11 of the uninterrupted power supply conversion circuit 10, respectively. When powered on, the host computer 61 obtains the power grid information through the energy storage converter 20 and obtains the power information of the battery module 50 through the battery management module 62, and outputs a switching signal to control the on-off of the switch module 11 and outputs a power control signal to control the energy storage converter 20 to perform bidirectional power conversion output and / or on-off based on the power grid information and the power information.

[0113] In this embodiment, the battery management module 62 is used to perform battery management of the battery module 50 when powered on, including charge management, discharge management, and battery state management, to prevent overcharging, overdischarging, overvoltage, and overcurrent management of the battery. The battery management module 62 can adopt a BMS battery management system.

[0114] The upper computer 61 completes the overall work of the control management module 60. In the grid-connected state of the power grid 2, the energy storage converter 20 obtains power from the power grid 2, the uninterrupted power supply conversion circuit 10 obtains power from the power grid 2, the battery management module 62 and the upper computer 61 obtain power supply sources through the first power conversion circuit 12 and the redundant power supply circuit 14 in the uninterrupted power supply conversion circuit 10. The upper computer 61 first outputs a switching control signal to the switching module 11 in the uninterrupted power supply conversion circuit 10 to control the switching module 11 to be turned on, and then outputs a power control signal to the energy storage converter 20 to control the energy storage converter 20 to convert the alternating current power supply of the power grid 2 into a charging power supply. The charging power supply charges the battery module 50 through the switching module 11.

[0115] When the power grid 2 is powered off, the uninterrupted power supply conversion circuit 10 obtains direct current power supply from the battery module 50, the control management module 60 obtains power supply sources through the second power conversion circuit 13 and the redundant power supply circuit 14 in the uninterrupted power supply conversion circuit 10, and the battery management module 62 and the upper computer 61 obtain power. After being powered, the upper computer 61 can first output a switching control signal to the switching module 11 in the uninterrupted power supply conversion circuit 10 to control the switching module 11 to be turned on or maintained to be turned on, and then output a power control signal to the energy storage converter 20. The direct current power supply of the battery module 50 is converted into alternating current power supply through the energy storage converter 20, and the alternating current power supply is output to the power grid 2. The switching module 11 is guaranteed not to be turned off due to temporary power loss, the entire control system is guaranteed to be powered, each load 3 in the system can be started, and the power of the entire system is finally restored.

[0116] In order to reliably perform the control management work of the energy storage converter 20, in one embodiment, the upper computer 61 is specifically used for:

[0117] receiving power grid information indicating that the power grid 2 is powered off, and obtaining the power information of the battery module 50;

[0118] when the power of the battery module 50 is greater than a preset value, switching to a black start mode, outputting a switching signal to control the switching module 11 to be turned on, and outputting a power control signal to control the energy storage converter 20 to convert the direct current power supply of the battery module 50 into alternating current power supply and output the alternating current power supply to the power grid 2 and the load 3, or to control the energy storage converter 20 to output the power of the photovoltaic module 30 and / or the wind power module 40 to the power grid 2 and / or the load 3;

[0119] and when the power of the battery module 50 is less than the preset value, outputting a power control signal to control the energy storage converter 20 to stop working, or when the power of the battery module 50 is less than the preset value, controlling the energy storage converter 20 to output the power of the photovoltaic module 30 and / or the wind power module 40 to the power grid 2 and / or the load 3;

[0120] When receiving the grid information indicating that the load power of the load 3 is less than the preset load power, the control unit controls the energy storage converter 20 to output the power of the photovoltaic module 30 and / or the wind power module 40 to the grid 2 and / or the load 3.

[0121] When receiving the grid information indicating that the grid 2 is initially connected to the grid or restored to the grid, the output power control signal controls the energy storage converter 20 to convert the alternating current power of the grid 2 into direct current power and output to the battery module 50 through the switch module 11.

[0122] In the embodiment, the host computer 61 obtains the state of the grid 2 through the energy storage converter 20, and the energy storage converter 20 outputs the grid information to the host computer 61. Meanwhile, the host computer 61 also obtains the power information of the battery module 50 through the battery management module 62.

[0123] When detecting that the grid 2 is connected to the grid, it indicates that the energy storage converter 20 takes power from the grid 2. At this time, the charging work of the battery module 50 can be performed. After the host computer 61 obtains the power supply through the uninterrupted power supply conversion circuit 10, the host computer 61 first outputs the switch control signal to the switch module 11 in the uninterrupted power supply conversion circuit 10 to control the switch module 11 to be turned on, and then outputs the power control signal to the energy storage converter 20. The energy storage converter 20 performs AC-DC conversion and outputs the charging power to the battery module 50.

[0124] When receiving the grid information indicating that the grid 2 is disconnected, it indicates that the grid 2 is off-grid. At this time, black start is needed to complete the self-start of the overall system. Meanwhile, in order to avoid over-discharge of the battery, the host computer 61 also synchronously refers to the power information of the battery module 50. When the power of the battery module 50 is greater than the preset value, it indicates that the current battery module 50 can undertake the current discharging work. The host computer 61 first outputs the switch control signal to the switch module 11 in the uninterrupted power supply conversion circuit 10 to control the switch module 11 to be turned on, and then outputs the power control signal to control the energy storage converter 20 to perform DC-AC conversion and convert the direct current power of the battery module 50 into alternating current power and output to the grid 2, the load 3 connected to the grid 2 and the first power conversion circuit 12.

[0125] Correspondingly, when receiving the grid information indicating that the grid 2 is disconnected, but the power of the battery module 50 is lower than the preset value at this time, in order to avoid over-discharge of the battery and realize over-discharge protection, the host computer 61 controls the energy storage converter 20 to stop DC-AC conversion.

[0126] And when the power grid 2 is powered off, when the battery module 50 has more or less power than the preset value, the photovoltaic module 30 and / or the wind power module 40 can also provide power, and the upper computer 61 controls the energy storage converter 20 to output the power of the photovoltaic module 30 and / or the wind power module 40 to the power grid 2 and / or the load 3, thereby realizing black start, ensuring power supply of the entire control system, and at the same time driving the start of each load 3 in the system, and ultimately restoring the power of the entire system.

[0127] Wherein, a plurality of power intervals can be set, and the energy storage converter 20 is controlled in different modes according to different power intervals in which the power is located.

[0128] The preset value can be the corresponding power of the battery module 50 in the full power state. In an optional embodiment, the preset value is set to two protection values, wherein the first protection value is 5%-10% of the full power state of the battery module 50, and preferably 5%.

[0129] Wherein, the second protection value is 1%-5% of the full power state of the battery module 50, and preferably 3%.

[0130] Further, in order to realize other auxiliary protection of the micro-grid and the energy storage system 1, such as Figure 6 As shown in one of the embodiments, the control management module 60 further comprises:

[0131] The smoke sensing system 63 is connected with the uninterrupted power supply conversion circuit 10, and is used for smoke sensing protection work when powered on.

[0132] The fire extinguishing system 64 is connected with the uninterrupted power supply conversion circuit 10, and is used for fire extinguishing protection work when powered on.

[0133] The water immersion system 65 is connected with the uninterrupted power supply conversion circuit 10, and is used for water immersion protection work when powered on.

[0134] The temperature system 66 is connected with the uninterrupted power supply conversion circuit 10, and is used for temperature detection work when powered on.

[0135] The combustible gas detection system 67 is connected with the uninterrupted power supply conversion circuit 10, and is used for combustible gas detection work when powered on.

[0136] When the uninterrupted power supply conversion circuit 10 takes power from the power grid 2 or the battery module 50 and outputs power supply to the upper computer 61 and the battery management module 62, it also synchronously outputs to the smoke sensing system 63, the fire extinguishing system 64, the water immersion system 65, the temperature system 66 and the combustible gas detection system 67, so that the environmental detection system performs corresponding environmental detection and protection of the micro-grid and the energy storage system 1.

[0137] The smoke sensing system 63 can be provided with corresponding smoke sensing sensors, processing circuits and alarm circuits to realize smoke detection and alarm protection.

[0138] The fire fighting system 64 can be provided with corresponding fire alarms, water sprinkler systems and alarm circuits to realize corresponding fire detection and protection.

[0139] The water immersion system 65 can be provided with corresponding water level sensors, processing circuits and alarm circuits to realize corresponding water protection.

[0140] The temperature system 66 can be provided with temperature sensors, alarms and the like to realize over-temperature detection and protection.

[0141] The flammable gas detection system 67 can be provided with corresponding flammable gas sensors, processing circuits and alarm circuits and the like to realize flammable gas detection and protection.

[0142] The above-described embodiments are only used to illustrate the technical solutions of the present application, and not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. An uninterrupted power supply conversion circuit for a micro-grid and energy storage system, the micro-grid and energy storage system comprising a battery module, a control management module, a photovoltaic module, a wind power module and an energy storage converter, the energy storage converter being connected with a power grid, the photovoltaic module, the wind power module, the battery module and the control management module respectively, the control management module being configured to output a power supply control signal to control the energy storage converter to perform bidirectional power conversion output and / or on-off after being powered on, and the power grid being further connected with a load; characterized in that, The uninterrupted power supply conversion circuit comprises: a switch module connected between the energy storage converter and the battery module, the switch module being triggered to turn on or turn off by a switch control signal output by the control management module; a first power conversion circuit connected to the AC end of the energy storage converter and the power grid, the first power conversion circuit being configured to convert AC power from the power grid or the energy storage converter into a first DC power; a second power conversion circuit connected to the power supply end of the battery module, the second power conversion circuit being configured to convert DC power from the battery module into a second DC power, the first DC power and the second DC power being the same; a redundant power supply circuit connected to the first power conversion circuit, the second power conversion circuit and the control management module, the redundant power supply circuit being configured to convert the first DC power or the second DC power into a power supply power and provide the power supply power for the control management module, wherein the power supply priority of the first power conversion circuit is higher than that of the second power conversion circuit, wherein the first power conversion circuit obtains power from the power grid in the grid-connected state, and the first power conversion circuit has no power input in the grid-off state, and the second power conversion circuit obtains DC power from the battery module; wherein, in the grid-off state, when the power of the battery module is greater than or less than a preset value, the upper computer controls the energy storage converter to output the power of the photovoltaic module and / or the wind power module to the power grid and / or the load; the photovoltaic module and / or the wind power module can also charge the battery module through the energy storage converter.

2. The uninterrupted power supply conversion circuit of claim 1, wherein, The switch module comprises: a first switch circuit connected between the energy storage converter and the battery module, the first switch circuit being triggered to turn on or turn off by a received switch signal; a switch control circuit connected to the redundant power supply circuit, the first switch circuit and the control management module, the switch control circuit being configured to obtain power supply power from the redundant power supply circuit and output the switch signal based on a switch control signal output by the control management module.

3. The uninterrupted power supply conversion circuit of claim 1, wherein the energy storage converter is provided with a controller, the controller being configured to receive the power control signal and control the energy storage converter to perform bidirectional power conversion output and / or on-off when powered on. characterized in that The redundant power supply circuit is also connected to the power supply end of the controller of the energy storage converter and provides power supply power.

4. The uninterrupted power supply conversion circuit of claim 1, wherein, The first power conversion circuit and the second power conversion circuit are switching power supply circuits.

5. The uninterrupted power supply conversion circuit of claim 1, wherein, The redundant power supply circuit comprises a switching power supply circuit; and / or, comprises a power supply switching circuit, the power supply switching circuit comprising: a second switch circuit, arranged between the first input end and the output end of the power supply switching circuit, for connecting a first path between the first input end and the output end when the first DC power supply is input into the first input end, so that the first DC power supply outputs the power supply through the output end; and for disconnecting the first path when the first DC power supply is not input into the first input end; a third switch circuit, arranged between the second input end and the output end of the power supply switching circuit, and the control end of the third switch circuit is connected to the first input end, for disconnecting a second path between the second input end and the output end when the first DC power supply is input into the first input end; and for connecting the second path when the first DC power supply is not input into the first input end and the second DC power supply is input into the second input end, so that the second DC power supply outputs the power supply through the output end.

6. A microgrid and energy storage system, characterized by, The uninterrupted power supply conversion circuit comprises a battery module, a control management module, a photovoltaic module, a wind power module, an energy storage converter, and the uninterrupted power supply conversion circuit according to any one of claims 1-5. The uninterrupted power supply conversion circuit is configured to obtain power supply from the battery module or the power grid and convert the power supply into a power supply. The control management module is configured to output a switch control signal to control the on-off of the switch module of the uninterrupted power supply conversion circuit and output a power supply control signal to control the energy storage converter to perform bidirectional power conversion output and / or on-off after power-on.

7. The microgrid and energy storage system of claim 6, wherein, The control management module comprises: The battery management module is connected to the uninterrupted power supply conversion circuit and the battery module, and is configured to obtain the power of the battery module and perform battery management after power-on. The host computer is connected to the redundant power supply circuit of the uninterrupted power supply conversion circuit, the battery management module, the energy storage converter, and the switch module of the uninterrupted power supply conversion circuit, and is configured to obtain power grid information through the energy storage converter and obtain power information of the battery module through the battery management module after power-on, and output the switch control signal to control the on-off of the switch module and output the power supply control signal to control the energy storage converter to perform bidirectional power conversion output and / or on-off based on the power grid information and the power information.

8. The microgrid and energy storage system of claim 7, wherein, The host computer is specifically configured to: obtain the power information of the battery module when receiving the power grid information representing power-off of the power grid. When the power of the battery module is greater than a preset value, the black start mode is switched to, and a switch signal is output to control the switch module to be turned on, and a power supply control signal is output to control the energy storage converter to convert the direct current power of the battery module into alternating current power and output to the power grid and the load, or control the energy storage converter to output the power of the photovoltaic module and / or the wind power module to the power grid and / or the load; When the power of the battery module is less than a preset value, a power supply control signal is output to control the energy storage converter to stop working, or when the power of the battery module is less than a preset value, the energy storage converter is controlled to output the power of the photovoltaic module and / or the wind power module to the power grid and / or the load; When receiving power grid information indicating that the load power of the load is less than a preset load power, the energy storage converter is controlled to output the power of the photovoltaic module and / or the wind power module to the power grid and / or the load; When receiving power grid information indicating that the power grid is initially connected to the grid or the power grid is restored to be connected to the grid, the power supply control signal is output to control the energy storage converter to convert the alternating current power of the power grid into direct current power and output to the battery module through the switch module.

9. The microgrid and energy storage system of claim 8, wherein, The energy storage converter is a three-phase four-wire energy storage converter. Alternatively, the energy storage converter comprises a transformer, and the transformer comprises a first phase line, a second phase line, a third phase line and a neutral line.

10. The microgrid and energy storage system of claim 7, wherein, The control management module further comprises: a smoke sensing system connected with the uninterrupted power supply conversion circuit, used for smoke sensing protection work when powered on; a fire extinguishing system connected with the uninterrupted power supply conversion circuit, used for fire extinguishing protection work when powered on; a water immersion system connected with the uninterrupted power supply conversion circuit, used for water immersion protection work when powered on; a temperature system connected with the uninterrupted power supply conversion circuit, used for temperature detection work when powered on; a combustible gas detection system connected with the uninterrupted power supply conversion circuit, used for combustible gas detection work when powered on.

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