Power supply conversion circuit for uninterruptedly supplying power to outside, micro-grid and energy storage system

Abstract

The invention provides a power supply conversion circuit for external uninterruptible power supply and a micro-grid and energy storage system.The power supply conversion circuit is used for the micro-grid and energy storage system and comprises a switch module, a first power supply conversion circuit, a second power supply conversion circuit and a redundant power supply circuit; the second power conversion circuit takes power from the micro-grid and the battery module of the energy storage system, and supplies power to the control management module through the redundant power supply circuit, thereby achieving the uninterrupted power supply of the control management module. The control management module can perform black start of the energy storage system, output a corresponding power supply control signal to the energy storage converter and output a switch control signal to the switch module so as to control the battery module to perform discharge work through the energy storage converter and complete a black start action function, thereby driving each load in the system to start. And moreover, a UPS (Uninterrupted Power Supply) mounting structure and UPS equipment do not need to be arranged, so that the design cost and the maintenance cost are reduced.

Description

Technical Field

[0001] The present invention belongs to the field of microgrid and energy storage technology, and in particular relates to an uninterruptible power supply conversion circuit and a microgrid and energy storage system. Background Art

[0002] The microgrid and energy storage system consists of PCS (Power Conversion System, energy storage converter), battery module, host computer, fire protection system, cooling system, etc. Among them, the battery module is connected to the grid through the switch module and the energy storage converter. When the switch module is turned on, the energy storage converter charges or discharges the battery module. During the discharge process, the battery discharges and supplies power to the load and / or discharges the grid through the energy storage converter, performs frequency modulation and peak regulation, etc. During the charging process, the battery is charged through the energy storage converter.

[0003] In the off-grid state, the microgrid and energy storage system need to perform a black start operation. A black start means that after the entire system stops operating due to a fault, the entire system is completely blacked out and is in a completely "black" state. It does not rely on the help of other power networks. The generator sets with self-starting capabilities in the system are started to drive the generator sets without self-starting capabilities, gradually expanding the system recovery range and ultimately achieving the recovery of the entire system.

[0004] The traditional black start method is to use UPS (Uninterrupted Power Supply) to power the control part of the energy storage system and turn on the control switch to achieve black start. However, the UPS solution has high power and high cost, and has a limited service life and an increased number of failure points, resulting in high black start costs and equipment maintenance costs. Summary of the invention

[0005] The purpose of the present invention is to provide a power supply conversion circuit for uninterrupted power supply, aiming to solve the problems of high power and high cost in the traditional black start method.

[0006] A first aspect of an embodiment of the present invention provides an uninterruptible power supply conversion circuit for a microgrid and an energy storage system, wherein the microgrid and the energy storage system include a battery module, a control management module, a photovoltaic module, a wind power module, and an energy storage converter, wherein the energy storage converter is respectively connected to the power grid, the photovoltaic module, the wind power module, the battery module, and the control management module, wherein the control management module is used to output a power control signal after power-on to control the energy storage converter to perform bidirectional power conversion output and / or switching, and the power grid is also connected to a load; The uninterruptible power supply conversion circuit comprises: A switch module, connected between the energy storage converter and the battery module, the switch module is triggered to turn on or off by a switch control signal output by the control management module; A first power conversion circuit is connected to the AC end of the power grid and the energy storage converter, and the first power conversion circuit is used to convert the AC power of the power grid or the energy storage converter into a first DC power supply; A second power conversion circuit is connected to the power supply terminal of the battery module, and the second power conversion circuit is used to convert the DC power supply of the battery module into a second DC power supply, and the first DC power supply and the second DC power supply are the same; A redundant power supply circuit is respectively connected to the first power conversion circuit, the second power conversion circuit and the control management module, and the redundant power supply circuit is used to convert the first DC power supply or the second DC power supply into a power supply and provide a power supply for the control management module, wherein the power supply priority of the first power conversion circuit is greater than the power supply priority of the second power conversion circuit.

[0007] In one embodiment, the switch module includes: A first switch circuit is connected between the energy storage converter and the battery module, and the first switch circuit is triggered to turn on or off by a received switch signal; The switch control circuit is respectively connected to the redundant power supply circuit, the first switch circuit and the control management module. The switch control circuit is used to obtain power supply through the redundant power supply circuit and output the switch signal based on the switch control signal output by the control management module.

[0008] In one embodiment, the energy storage converter is provided with a controller, and the controller is used to receive the power control signal when powered on and control the energy storage converter to perform bidirectional power conversion output and / or switching; The redundant power supply circuit is also connected to the power supply terminal of the controller of the energy storage converter and provides power supply.

[0009] In one embodiment, the first power conversion circuit and the second power conversion circuit are switching power circuits.

[0010] In one of the embodiments, the redundant power supply circuit includes a switching power supply circuit; And / or, comprising a power supply switching circuit, the power supply switching circuit comprising: a second switch circuit, arranged 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 input to 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 input to the first input terminal; A third switch circuit is arranged between the second input terminal and the output terminal of the power supply switching circuit, and a controlled end of the third switch circuit is connected to the first input terminal, and is used to disconnect the second path between the second input terminal and the output terminal when the first DC power supply is input to the first input terminal; and is used to connect the second path when the first DC power supply is not input to the first input terminal and the second DC power supply is input to the second input terminal, so that the second DC power supply outputs the power supply through the output terminal.

[0011] A second aspect of an embodiment of the present invention provides a microgrid and energy storage system, including a battery module, a control management module, a photovoltaic module, a wind power module, an energy storage converter and the uninterruptible power supply conversion circuit as described above, wherein the energy storage converter is respectively connected to the power grid, the photovoltaic module, the wind power module, the uninterruptible power supply conversion circuit and the control management module, the uninterruptible power supply conversion circuit is also connected to the battery module, the control management module and the power grid, and the power grid is also connected to a load; The uninterruptible power supply conversion circuit is used to obtain power from the battery module or the power grid and convert it into power supply; The control management module is used to output a switch control signal after power-on to control the on / off of the switch module of the power supply conversion circuit of the uninterruptible power supply, and output a power supply control signal to control the energy storage inverter to perform bidirectional power supply conversion output and / or on / off.

[0012] In one embodiment, the control management module includes: A battery management module, connected to the uninterruptible power supply conversion circuit and the battery module, the battery management module is used to obtain the power of the battery module when powered on and perform battery management; The host computer is respectively connected to the power conversion circuit of the uninterruptible power supply, the battery management module, the energy storage inverter and the switch module of the power conversion circuit of the uninterruptible power supply, and is used to obtain power grid information through the energy storage inverter and obtain power information of the battery module through the battery management module when power is turned on, and output the switch control signal based on the power grid information and the power information to control the on and off of the switch module, and output the power control signal to control the energy storage inverter to perform bidirectional power conversion output and / or on and off.

[0013] In one embodiment, the host computer is specifically used for: Upon receiving the grid information indicating a power outage in the grid, acquiring power information of the battery module; When the power of the battery module is greater than a preset value, switch to the black start mode, output a switch signal to control the switch module to be turned on, and output a power control signal to control the energy storage inverter to convert the DC power of the battery module into AC power and output it to the power grid and the load, or control the energy storage inverter to output the power of the photovoltaic module and / or wind power module to the power grid and / or the load; And when the power of the battery module is less than a preset value, the output power control signal controls the energy storage converter to stop working, or, when the power of the battery module is less than a preset value, controls the energy storage converter to output the power of the photovoltaic module and / or wind power module to the power grid and / or load; Upon receiving grid information indicating that the load power supply of the load is less than a preset load power supply, controlling the energy storage converter to output the electric energy of the photovoltaic module and / or wind power module to the grid and / or the load; When grid information indicating initial grid connection or grid restoration of the grid is received, the power control signal is output to control the energy storage converter to convert the AC power of the grid into DC power, and output it to the battery module through the switch module.

[0014] In one embodiment, the energy storage converter is a three-phase four-wire energy storage converter; 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.

[0015] In one embodiment, the control management module further includes: A smoke sensing system, connected to the uninterruptible power supply conversion circuit, for performing smoke sensing protection when powered on; A fire protection system, connected to the power supply conversion circuit of the uninterruptible power supply, for performing fire protection work when power is on; A water immersion system, connected to the power supply conversion circuit of the uninterruptible power supply, for performing water immersion protection work when power is turned on; A temperature system, connected to the power supply conversion circuit of the uninterruptible power supply, for performing temperature detection when power is turned on; The combustible gas detection system is connected to the power supply conversion circuit of the uninterruptible power supply and is used for performing combustible gas detection work when power is turned on.

[0016] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the power supply conversion circuit includes a switch module, a first power conversion circuit, a second power conversion circuit and a redundant power supply circuit. When the power grid is normally connected to the grid, the power supply priority of the first power conversion circuit is greater than the priority of the second power conversion circuit. The first power conversion circuit draws power from the power grid and supplies power to the control management module of the microgrid and the energy storage system through the redundant power supply circuit. When the power grid is powered off, the second power conversion circuit draws power from the battery module of the microgrid and the energy storage system and supplies power to the control management module through the redundant power supply circuit, thereby realizing uninterrupted power supply to the control management module. The control management module can perform a black start of the energy storage system and output a corresponding power control signal to the energy storage inverter and an output switch control signal to the switch module, so as to control the battery module to discharge through the energy storage inverter, complete the black start action function, thereby driving the start of each load in the system, and finally restoring the power of the entire system. There is no need to set up a UPS installation structure and introduce UPS equipment, thereby reducing design costs and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A first structural schematic diagram of a microgrid and energy storage system provided in an embodiment of the present invention; Figure 2 A second structural schematic diagram of a microgrid and energy storage system provided in an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a redundant power supply circuit provided by an embodiment of the present invention; Figure 4 A schematic diagram of the circuit structure of a redundant power supply circuit provided in an embodiment of the present invention; Figure 5 A third structural schematic diagram of a microgrid and energy storage system provided in an embodiment of the present invention; Figure 6 A fourth structural schematic diagram of a microgrid and energy storage system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0020] A first aspect of an embodiment of the present invention provides an uninterruptible power supply conversion circuit 10 for use in a microgrid and an energy storage system 1, such as Figure 1 As shown, the microgrid 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 inverter 20. The energy storage inverter 20 is respectively connected to the power grid 2, the photovoltaic module 30, the wind power module 40, the battery module 50 and the control management module 60. The control management module 60 is used to output a power control signal after power-on to control the energy storage inverter 20 to perform bidirectional power conversion output and / or switching.

[0021] In this embodiment, the control management module 60 performs control and management of the energy storage inverter 20 and the battery module 50. By outputting corresponding power control signals, the energy storage inverter 20 can perform conversion work from AC power to DC power and on-off control, and can also perform conversion work from DC power to AC power and on-off control.

[0022] The microgrid and energy storage system 1 can operate when the grid 2 is connected to the grid or the grid 2 is powered off. When the grid 2 is connected to the grid, that is, when the grid 2 is energized, the grid 2 outputs power to the load 3 connected to the grid 2 on the one hand, and on the other hand, the grid 2 outputs AC power to the energy storage inverter 20. The energy storage inverter 20 performs AC-to-DC conversion under the control of the power control signal, converts the AC power into charging power, and outputs it to the battery module 50 for charging.

[0023] When the power grid 2 is out of power, the control management module 60 needs to be powered on and perform black start control, and output a power control signal to control the energy storage inverter 20 to perform battery discharge, so as to output AC power to the power grid 2 and each load 3 or generator connected to the power grid 2, thereby realizing self-starting of the overall system.

[0024] At the same time, when the power grid 2 is normal or power-off, 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 inverter 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 to the load 3 through the energy storage inverter 20.

[0025] The battery module 50 may include one or more battery packs connected in series and parallel, and the specific structure is not limited.

[0026] The control management module 60 may include a corresponding battery management module 62 , a host computer 61 and other modules.

[0027] In order to realize reliable power supply of the control management module 60 and ensure that it can perform corresponding power control work under different states of the power grid 2, in this embodiment, the microgrid and energy storage system 1 also includes an uninterruptible power supply power conversion circuit 10, and the uninterruptible power supply power conversion circuit 10 is respectively connected to the energy storage converter 20, the power grid 2, the battery module 50 and the control management module 60, wherein, as Figure 1 As shown, the uninterruptible power supply conversion circuit 10 includes: The switch module 11 is connected between the energy storage converter 20 and the battery module 50. The switch module 11 is triggered to turn on or off by a switch control signal output by the control management module 60; A first power conversion circuit 12 is connected to the AC end of the power grid 2 and the energy storage converter 20, and the first power conversion circuit 12 is used to convert the AC power of the power grid 2 or the energy storage converter 20 into a first DC power supply; A second power conversion circuit 13 is connected to the power supply terminal of the battery module 50. The second power conversion circuit 13 is used to convert the DC power supply of the battery module 50 into a second DC power supply. The first DC power supply and the second DC power supply are the same. The redundant power supply circuit 14 is respectively connected to the first power conversion circuit 12, the second power conversion circuit 13 and the control management module 60. The redundant power supply circuit 14 is used to convert the first DC power supply or the second DC power supply into a power supply and provide a power supply for the control management module 60. The power supply priority of the first power conversion circuit 12 is greater than the power supply priority of the second power conversion circuit 13.

[0028] In this embodiment, when the power grid 2 is connected to the grid, the energy storage inverter 20 draws power from the power grid 2, the first power conversion circuit 12 draws power from the power grid 2, and converts the AC power of the power grid 2 into a first DC power. Since the power supply priority of the first power conversion circuit 12 is greater than that of the second power conversion circuit 13, the first DC power is output to the control management module 60 through the redundant power supply circuit 14. The control management module 60 first outputs a switch control signal to the switch module 11 to control the switch module 11 to be turned on, and then outputs a power control signal to the energy storage inverter 20 to control the energy storage inverter 20 to convert the AC power of the power grid 2 into a power supply, and the charging power charges the battery module 50 through the switch module 11.

[0029] 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 DC power through the battery module 50 and converts it into a second DC power. The second DC power is equal to the first DC power in voltage and current. The second DC power is output to the control management module 60 through the redundant power supply circuit 14 to achieve uninterrupted power supply to the control management module 60. After the control management module 60 is powered, it can first output a switch control signal to the switch module 11 to control the switch module 11 to be turned on or maintained turned on, and then output a power control signal to the energy storage inverter 20. The DC power of the battery module 50 is output to the DC end of the energy storage inverter 20 through the switch module 11. The energy storage inverter 20 performs DC to AC conversion and outputs AC power to the power grid 2, ensuring that the switch module 11 will not be disconnected due to a temporary power failure, ensuring that the entire control system is powered, and at the same time, it can drive each load 3 in the system to start, and finally restore the power of the entire system.

[0030] After the power grid 2 draws power through the energy storage inverter 20, the first power conversion circuit 12 draws power again and outputs the first DC power supply 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 DC power supply, and the first DC power supply is converted into power supply to the control management module 60.

[0031] After the power grid 2 is restored and connected to the grid, the first power conversion circuit 12 directly draws power from the power grid 2 and outputs the first DC power supply 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 DC power supply, and the first DC power supply is converted into power supply to the control management module 60.

[0032] By providing a first power conversion circuit 12, a second power conversion circuit 13 and a redundant power supply circuit 14, it can be ensured that the microgrid and the energy storage system 1 can maintain a power supply working state under different working conditions, and the power management and control work of the microgrid and the energy storage system 1 can be maintained, thereby improving the working reliability and stability of the microgrid and the energy storage system 1.

[0033] And there is no need to set up a UPS, which can reduce the design cost or maintenance cost of the micro-current energy storage system. The first power conversion circuit 12, the second power conversion circuit 13 and the redundant power supply circuit 14 are used for power conversion, and no additional power consumption is generated, thereby reducing system power consumption.

[0034] In addition, the uninterruptible power supply conversion circuit 10 is used to provide uninterruptible power supply, which can ensure that the data acquisition, security and fire protection systems can work normally in the event of a sudden power outage in the power grid 2, report and quickly eliminate potential safety hazards, and ensure the safety of the system.

[0035] 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 corresponding switch on-off control can be achieved by manually controlling the switches of the first power conversion circuit 12 and the second power conversion circuit 13.

[0036] The switch module 11 may use a single switch device or add a corresponding drive control device. In an optional embodiment, Figure 2 As shown, in one embodiment, the switch module 11 includes: A first switch circuit 111 is connected between the energy storage converter 20 and the battery module 50. The first switch circuit 111 is triggered to turn on or off by a received switch signal; The switch control circuit 112 is connected to the redundant power supply circuit 14, the first switch circuit 111 and the control management module 60 respectively. The switch control circuit 112 is used to obtain power supply through the redundant power supply circuit 14 and output a switch signal based on the switch control signal output by the control management module 60.

[0037] In this embodiment, since a high voltage is passed between the energy storage inverter 20 and the battery module 50, the switch control signal output by the control management module 60 is a low voltage. In order to realize the control work from low voltage to high voltage, the switch control circuit 112 is connected to the first switch circuit 111 and the control management module 60, and the switch control circuit 112 can be used for signal amplification or conversion of the switch control signal.

[0038] When the power grid 2 is connected to the grid or the power is cut off, the redundant power supply circuit 14 can obtain power supply from the first power conversion circuit 12 or the second power conversion circuit 13, and the power supply is synchronously output to the control management module 60 and the switch control circuit 112, so as to realize uninterrupted power supply to the control management module 60 and the switch control circuit 112. Under the drive of 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, so as to control the first switch circuit 111 to be turned on or off.

[0039] The first switch circuit 111 may be a controllable switch such as a relay, a circuit breaker, an electronic switch, a semiconductor, etc., and the switch control circuit 112 may be a coil power supply circuit, a signal amplification circuit, etc.

[0040] In an optional embodiment, the first switch circuit 111 and the switch control circuit 112 are centrally arranged and arranged in a high-voltage box, and the energy storage converter 20 performs charging and discharging operations between the high-voltage box and the battery module 50 .

[0041] In one embodiment, a controller is provided in the energy storage inverter 20, and the energy storage inverter 20 also includes a bidirectional power conversion circuit, which is used to perform bidirectional conversion of AC and DC. The controller is used to receive a power control signal when powered on and control the bidirectional power conversion circuit of the energy storage inverter 20 to perform bidirectional power conversion output and / or switching.

[0042] Correspondingly, in order to ensure that the controller is powered on normally and the energy storage converter 20 is driven normally, as shown in FIG. 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.

[0043] When the power grid 2 is connected to the grid or the power is cut off, the redundant power supply circuit 14 can obtain power supply from the first power conversion circuit 12 or the second power conversion circuit 13, and the power supply is synchronously output to the control management module 60, the switch control circuit 112 and the controller of the energy storage inverter 20, 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 inverter 20. Driven by 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.

[0044] Among them, the first power conversion circuit 12 and the second power conversion circuit 13 can adopt corresponding power supply circuits. In order to realize AC-DC conversion, in one embodiment, the first power conversion circuit 12 and the second power conversion circuit 13 are switching power supply circuits. The switching power supply circuit includes an input rectifier and filter circuit, an inverter circuit, a transformer, an output rectifier and filter circuit, etc., which can perform AC-to-DC conversion, and can also perform DC-to-DC conversion.

[0045] Correspondingly, in one of the embodiments, the redundant power supply circuit 14 includes a switching power supply circuit; And / or, includes a power supply switching circuit 141.

[0046] When the redundant power supply circuit 14 includes a switching power supply circuit, a corresponding sampling circuit can be set in the switching power supply circuit. The sampling circuit adopts the input status of the first power conversion circuit 12 and the second power conversion circuit 13. The control unit in the switching power supply circuit sets the power supply priority according to the sampling signal, and gives priority to inputting the first DC power supply of the first power conversion circuit 12.

[0047] 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 switch unit, and the switch unit is turned on or off according to the input 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.

[0048] 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 to perform power conversion. 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 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.

[0049] In an alternative embodiment, if Figure 3 As shown, the power supply switching circuit 141 includes: The second switch circuit 1411 is provided between the first input terminal and the output terminal of the power supply switching circuit 141, and is used to connect the first path between the first input terminal and the output terminal when the first DC power supply is input to the first input terminal, so that the first DC power supply outputs the power supply through the output terminal; and is used to disconnect the first path when the first DC power supply is not input to the first input terminal; 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 controlled end of the third switch circuit 1412 is connected to the first input terminal, and is used to disconnect the second path between the second input terminal and the output terminal when the first DC power supply is input to the first input terminal; and is used to connect the second path when the first DC power supply is not input to the first input terminal and the second DC power supply is input to the second input terminal, so that the second DC power supply outputs the power supply through the output terminal.

[0050] In this embodiment, it is assumed that the redundant power supply circuit 14 includes a 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 turn on, and the third switch circuit 1412 is triggered to turn off. The first DC power is output through the second switch circuit 1411 and is output as a power supply to the control management module 60, the switch control circuit 112 and the controller.

[0051] And 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 shut down, and the third switch circuit 1412 is triggered to turn on, and the second DC power is output through the third switch circuit 1412 and output as a power supply to the control management module 60, the switch control circuit 112 and the controller, thereby realizing uninterrupted power supply to the control management module 60, the switch control circuit 112 and the controller of the energy storage inverter 20.

[0052] The second switch circuit 1411 and the third switch circuit 1412 may use corresponding types of switch devices, such as Figure 4As 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 end of the first resistor R1 and the first end of the second electronic switch tube Q2 are linked to form an input end of the second switch circuit 1411. The second end of the first resistor R1, the first end of the second resistor R2 and the control end of the first electronic switch tube Q1 are connected. The second end of the second resistor R2 and the first end of the first electronic switch tube Q1 are connected and grounded. The output end of the first electronic switch tube Q1 is connected to the first end of the third resistor R3. The second end of the third resistor R3 is connected to the control end of the second electronic switch tube Q2. The second end of the second electronic switch tube Q2 constitutes the output end of the second switch circuit 1411.

[0053] The third switch circuit 1412 includes 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.

[0054] When the first power conversion circuit 12 outputs the first DC power supply 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 turn on, and the third electronic switch tube Q3 receives a high level trigger to turn off, and the first DC power supply is output through the second electronic switch tube Q2 and output as a power supply to the control management module 60, the switch control circuit 112 and the controller.

[0055] And 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 first electronic switch tube Q1 and the second electronic switch tube Q2 are triggered to turn off, and the third electronic switch is triggered to turn on by receiving a low level, and the second DC power is output through the third open electronic switch tube and output as a power supply to the control management module 60, the switch control circuit 112 and the controller, thereby realizing uninterrupted power supply to the control management module 60, the switch control circuit 112 and the controller of the energy storage inverter 20.

[0056] The first electronic switch tube Q1 is an NMOS tube, and the second electronic switch tube Q2 and the third electronic switch tube Q3 are PNP transistors.

[0057] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the above-mentioned uninterruptible power supply power conversion circuit 10 includes a switch module 11, a first power conversion circuit 12, a second power conversion circuit 13 and a redundant power supply circuit 14. When the power grid 2 is normally connected to the grid, the power supply priority of the first power conversion circuit 12 is greater than the priority of the second power conversion circuit 13. The first power conversion circuit 12 draws power from the power grid 2 and supplies power to the control management module 60 of the microgrid and the energy storage system 1 through the redundant power supply circuit 14. When the power grid 2 is powered off, the second power conversion circuit 13 draws power from the battery module 50 of the microgrid and the 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 a black start and output a corresponding power control signal to the energy storage converter 20 and an output switch control signal 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 finally restoring the power of the entire system. There is no need to set up a UPS structure, which reduces the design cost and maintenance cost.

[0058] The present invention also proposes a microgrid and energy storage system 1, which includes a battery module 50, a control management module 60, a photovoltaic module 30, a wind power module 40, an energy storage inverter 20 and an uninterruptible power supply conversion circuit 10. The specific structure of the uninterruptible power supply conversion circuit 10 refers to the above embodiment. Since the present microgrid and energy storage system 1 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0059] The energy storage converter 20 is respectively connected to the power grid 2, the photovoltaic module 30, the wind power module 40, the uninterruptible power supply power conversion circuit 10 and the control management module 60, the uninterruptible power supply power conversion circuit 10 is also connected to the battery module 50, the control management module 60 and the power grid 2, and the power grid 2 is also connected to the load 3; The uninterruptible power supply conversion circuit 10 is used to obtain power from the battery module 50 or the power grid 2 and convert it into power supply to achieve uninterruptible power supply to the control management module 60; The control management module 60 is used to output a switch control signal after power-on to control the on / off of the switch module 11 of the uninterruptible power supply conversion circuit 10, and output a power supply control signal to control the energy storage converter 20 to perform bidirectional power conversion output and / or on / off.

[0060] In this embodiment, in order to achieve reliable power supply of the control management module 60 and ensure that it can perform corresponding power control work under different states of the power grid 2, the microgrid and energy storage system 1 also includes an uninterruptible power supply conversion circuit 10, and the uninterruptible power supply conversion circuit 10 is respectively connected to the energy storage inverter 20, the power grid 2, the battery module 50 and the control management module 60.

[0061] The control management module 60 performs control and management of the power supply conversion circuit 10, the energy storage inverter 20 and the battery module 50 of the uninterruptible power supply. By outputting corresponding switch control signals and power control signals, the switch module 11 of the power supply conversion circuit 10 of the uninterruptible power supply is controlled on and off, and the energy storage inverter 20 can perform conversion work from AC power to DC power and on and off control, and can also perform conversion work from DC power to AC power and on and off control.

[0062] The microgrid and energy storage system 1 can operate in a state where the grid 2 is connected to the grid or the grid 2 is powered off. When the grid 2 is connected to the grid, that is, when the grid 2 is energized, the grid 2 outputs power to the load 3 connected to the grid 2 on the one hand, and on the other hand, the grid 2 outputs AC power to the energy storage inverter 20. The uninterruptible power supply power conversion circuit 10 draws power from the grid 2, and the control management module 60 obtains power supply through the first power conversion circuit 12 and the redundant power supply circuit 14 in the uninterruptible power supply power conversion circuit 10. The control management module 60 first outputs a switch control signal to the switch module 11 in the uninterruptible power supply power conversion circuit 10 to control the switch module 11 to be turned on, and then outputs a power control signal to the energy storage inverter 20. The energy storage inverter 20 performs AC to DC conversion under the control of the power control signal, and converts the AC power into a charging power supply, and the charging power is output to the battery module 50 through the switch module 11 for charging.

[0063] When the power grid 2 is powered off, the uninterruptible power supply power conversion circuit 10 obtains DC power from the battery module 50, and the control management module 60 obtains power through the second power conversion circuit 13 and the redundant power supply circuit 14 in the uninterruptible power supply power conversion circuit 10. The control management module 60 can first output a switch control signal to the switch module 11 in the uninterruptible power supply power conversion circuit 10 to control the switch module 11 to be turned on or maintain conduction, and the control management module 60 is powered on and performs black start control, and then outputs a power control signal to control the energy storage inverter 20 to discharge the battery, so as to output AC power to the power grid 2 and each load 3 or generator connected to the power grid 2, so as to realize the self-starting of the entire system, ensure that the switch module 11 will not be disconnected due to a temporary power failure, ensure that the entire control system is powered on, and at the same time drive each load 3 in the system to start, and finally restore the power of the entire system.

[0064] At the same time, when the power grid 2 is normal or powered off, 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 inverter 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 to the power grid 2 and / or the load through the energy storage inverter 20.

[0065] The energy storage converter 20 may use a controller and a bidirectional power conversion circuit. When the power grid 2 is off-grid, it is necessary to output an AC power supply that satisfies the transmission of the power grid 2. In one embodiment, the energy storage converter 20 is a three-phase four-wire energy storage converter 20, corresponding to the form of the power grid 2. Alternatively, the energy storage converter 20 includes a transformer, which includes a first phase line, a second phase line, a third phase line, and a neutral line, and utilizes the neutral line mode of the transformer to implement a three-phase four-wire energy storage conversion function.

[0066] The battery module 50 may include one or more battery packs connected in series and parallel, and the specific structure is not limited.

[0067] The control management module 60 may include a corresponding battery management module 62, a host computer 61 and other modules. In one embodiment, Figure 5 As shown, the control management module 60 includes: The battery management module 62 is connected to the uninterruptible power supply conversion circuit 10 and the battery module 50, and the battery management module 62 is used to obtain the power of the battery module 50 when power is turned on and to perform battery management; The host computer 61 is respectively connected to the redundant power supply circuit 14 of the uninterruptible power supply power conversion circuit 10, the battery management module 62, the energy storage inverter 20 and the switch module 11 of the uninterruptible power supply power conversion circuit 10, and is used to obtain power grid information through the energy storage inverter 20 and the power information of the battery module 50 through the battery management module 62 when power is turned on, and output a switch signal based on the power grid information and the power information to control the switch module 11 to turn on and off, and output a power control signal to control the energy storage inverter 20 to perform bidirectional power conversion output and / or turn on and off.

[0068] In this embodiment, the battery management module 62 is used to perform battery management of the battery module 50 when power is turned on, including charging management, discharging management and battery status management, to prevent battery overcharging, over-discharging, overvoltage, overcurrent and other management tasks. The battery management module 62 can adopt a BMS battery management system, etc.

[0069] The host computer 61 completes the overall work of the control management module 60. When the power grid 2 is connected to the grid, the energy storage inverter 20 draws power from the grid 2, and the uninterruptible power supply power conversion circuit 10 draws power from the grid 2. The battery management module 62 and the host computer 61 obtain power supply through the first power conversion circuit 12 and the redundant power supply circuit 14 in the uninterruptible power supply power conversion circuit 10. The host computer 61 first outputs a switch control signal to the switch module 11 in the uninterruptible power supply power conversion circuit 10 to control the switch module 11 to be turned on, and then outputs a power control signal to the energy storage inverter 20 to control the energy storage inverter 20 to convert the AC power of the grid 2 into a charging power supply. The charging power charges the battery module 50 through the switch module 11.

[0070] When the power grid 2 is powered off, at this time, the uninterruptible power supply power conversion circuit 10 obtains DC power from the battery module 50, and the control management module 60 obtains power through the second power conversion circuit 13 and the redundant power supply circuit 14 in the uninterruptible power supply power conversion circuit 10. After the battery management module 62 and the host computer 61 are powered, the host computer 61 can first output a switch control signal to the switch module 11 in the uninterruptible power supply power conversion circuit 10 to control the switch module 11 to be turned on or maintain conduction, and then output a power control signal to the energy storage inverter 20. The DC power of the battery module 50 is converted from DC to AC through the energy storage inverter 20, and the AC power is output to the power grid 2, ensuring that the switch module 11 will not be disconnected due to a temporary power failure, ensuring that the entire control system is powered, and at the same time, it can drive each load 3 in the system to start, and finally restore the power of the entire system.

[0071] In order to reliably perform the control and management of the energy storage converter 20, in one embodiment, the host computer 61 is specifically used for: When receiving grid information indicating that the grid 2 is out of power, obtaining power information of the battery module 50; When the power of the battery module 50 is greater than a preset value, it switches to the black start mode, and outputs a switch signal to control the switch module 11 to be turned on, and outputs a power control signal to control the energy storage inverter 20 to convert the DC power of the battery module 50 into AC power and output it to the grid 2 and the load 3, or controls the energy storage inverter 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; When the power of the battery module 50 is less than a preset value, the output power control signal controls the energy storage converter 20 to stop working, or when the power of the battery module 50 is less than a preset value, 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; When receiving grid information indicating that the load power of the load 3 is less than the preset load power, the energy storage converter 20 is controlled to output the electric energy of the photovoltaic module 30 and / or the wind power module 40 to the grid 2 and / or the load 3; When grid information indicating that the grid 2 is initially connected to the grid or restored to the grid is received, the output power control signal controls the energy storage converter 20 to convert the AC power of the grid 2 into a DC power, and outputs it to the battery module 50 through the switch module 11 .

[0072] In this embodiment, the host computer 61 obtains the state of the power grid 2 through the energy storage converter 20 , and the energy storage converter 20 outputs the power 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 .

[0073] When it is detected that the grid 2 is connected to the grid, it indicates that the energy storage inverter 20 draws power from the grid 2. At this time, the battery module 50 can be charged. After the upper computer 61 obtains the power supply through the uninterruptible power supply power conversion circuit 10, the upper computer 61 first outputs a switch control signal to the switch module 11 in the uninterruptible power supply power conversion circuit 10 to control the switch module 11 to be turned on, and then outputs a power control signal to the energy storage inverter 20. The energy storage inverter 20 performs AC to DC conversion and outputs charging power to the battery module 50.

[0074] And when the grid information representing the power outage of grid 2 is received, it indicates that grid 2 is off the grid. At this time, a black start is required to complete the self-start of the overall system. At the same time, in order to avoid over-discharge of the battery, the upper 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 discharge work. The upper computer 61 first outputs a switch control signal to the switch module 11 in the power supply conversion circuit 10 of the uninterruptible power supply to control the switch module 11 to be turned on, and then outputs a power control signal to control the energy storage inverter 20 to perform DC to AC conversion, and converts the DC power of the battery module 50 into AC power, and outputs it to the grid 2 and the load 3 connected to the grid 2 and the first power conversion circuit 12.

[0075] Correspondingly, when grid information indicating a power outage in grid 2 is received, but the power level of battery module 50 is lower than a preset value, in order to avoid over-discharge of the battery and implement over-discharge protection, host computer 61 controls energy storage converter 20 to stop converting DC to AC.

[0076] Also, when the power grid 2 is out of power, when the power level of the battery module 50 is greater than a preset value or less than a preset value, electric energy can also be provided by the photovoltaic module 30 and / or the wind power module 40, and the upper computer 61 controls the energy storage inverter 20 to output the electric energy of the photovoltaic module 30 and / or the wind power module 40 to the power grid 2 and / or the load 3, thereby realizing a black start and ensuring that the entire control system is powered on, while driving each load 3 in the system to start, and finally restoring the power of the entire system.

[0077] Among them, multiple power intervals can be set, and different modes of control can be performed on the energy storage converter 20 according to the different power intervals in which the power is located.

[0078] The preset value may be the corresponding power of the battery module 50 in a fully charged state. In an optional embodiment, the preset value sets two levels of protection values, wherein the first level protection value is 5%-10% of the fully charged state of the battery module 50, preferably 5%.

[0079] The secondary protection value is 1%-5% of the fully charged state of the battery module 50 , preferably 3%.

[0080] Furthermore, in order to realize other auxiliary protection of the microgrid and the energy storage system 1, such as Figure 6 As shown, in one embodiment, the control management module 60 further includes: The smoke sensing system 63 is connected to the power supply conversion circuit 10 of the uninterruptible power supply and is used to perform smoke sensing protection when the power is turned on; The fire protection system 64 is connected to the power supply conversion circuit 10 of the uninterruptible power supply and is used to perform fire protection work when the power is turned on; The water immersion system 65 is connected to the uninterruptible power supply conversion circuit 10 and is used for performing water immersion protection when power is turned on.

[0081] The temperature system 66 is connected to the power supply conversion circuit 10 of the uninterruptible power supply and is used to perform temperature detection when power is turned on; The combustible gas detection system 67 is connected to the uninterruptible power supply conversion circuit 10 and is used to perform combustible gas detection when the power is turned on.

[0082] When the uninterruptible power supply conversion circuit 10 draws power from the power grid 2 or the battery module 50 and outputs the power supply to the host computer 61 and the battery management module 62, it also synchronously outputs it to the smoke detection system 63, the fire protection system 64, the water immersion system 65, the temperature system 66 and the combustible gas detection system 67, so that the environmental detection system can perform corresponding environmental detection and protection of the microgrid and the energy storage system 1.

[0083] The smoke sensing system 63 may be provided with corresponding smoke sensors, processing circuits and alarm circuits to achieve smoke detection and alarm protection.

[0084] The fire protection system 64 may be provided with corresponding fire alarms, sprinkler systems and alarm circuits to achieve corresponding fire protection detection and protection.

[0085] The water immersion system 65 can use corresponding water level sensors, processing circuits and alarm circuits to achieve corresponding waterproof protection.

[0086] The temperature system 66 may use temperature sensors, alarms, etc. to achieve over-temperature detection and protection.

[0087] The combustible gas detection system 67 can use corresponding combustible gas sensors, processing circuits, alarm circuits, etc. to achieve combustible gas detection and protection.

[0088] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A power supply conversion circuit for uninterruptible power supply, used for a microgrid and an energy storage system, wherein the microgrid and the energy storage system include a battery module, a control management module, a photovoltaic module, a wind power module and an energy storage converter, wherein the energy storage converter is respectively connected to the power grid, the photovoltaic module, the wind power module, the battery module and the control management module, wherein the control management module is used to output a power control signal after power-on to control the energy storage converter to perform bidirectional power conversion output and / or switching, and the power grid is also connected to a load; characterized in that The uninterruptible power supply conversion circuit comprises: A switch module, connected between the energy storage converter and the battery module, the switch module is triggered to turn on or off by a switch control signal output by the control management module; A first power conversion circuit is connected to the AC end of the power grid and the energy storage converter, and the first power conversion circuit is used to convert the AC power of the power grid or the energy storage converter into a first DC power supply; A second power conversion circuit is connected to the power supply terminal of the battery module, and the second power conversion circuit is used to convert the DC power supply of the battery module into a second DC power supply, and the first DC power supply and the second DC power supply are the same; A redundant power supply circuit is respectively connected to the first power conversion circuit, the second power conversion circuit and the control management module, and the redundant power supply circuit is used to convert the first DC power supply or the second DC power supply into a power supply and provide a power supply for the control management module, wherein the power supply priority of the first power conversion circuit is greater than the power supply priority of the second power conversion circuit.

2. The uninterruptible power supply conversion circuit according to claim 1, characterized in that: The switch module comprises: A first switch circuit is connected between the energy storage converter and the battery module, and the first switch circuit is triggered to turn on or off by a received switch signal; The switch control circuit is respectively connected to the redundant power supply circuit, the first switch circuit and the control management module. The switch control circuit is used to obtain power supply through the redundant power supply circuit and output the switch signal based on the switch control signal output by the control management module.

3. The uninterruptible power supply conversion circuit according to claim 1, wherein the energy storage converter is provided with a controller, and the controller is used to receive the power control signal when powered on and control the energy storage converter to perform bidirectional power conversion output and / or switching; It is characterized in that The redundant power supply circuit is also connected to the power supply terminal of the controller of the energy storage converter and provides power supply.

4. The uninterruptible power supply conversion circuit according to claim 1, characterized in that: The first power conversion circuit and the second power conversion circuit are switching power circuits.

5. The uninterruptible power supply conversion circuit according to claim 1, characterized in that: The redundant power supply circuit includes a switching power supply circuit; And / or, comprising a power supply switching circuit, the power supply switching circuit comprising: a second switch circuit, arranged 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 input to 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 input to the first input terminal; A third switch circuit is arranged between the second input terminal and the output terminal of the power supply switching circuit, and a controlled end of the third switch circuit is connected to the first input terminal, and is used to disconnect the second path between the second input terminal and the output terminal when the first DC power supply is input to the first input terminal; and is used to connect the second path when the first DC power supply is not input to the first input terminal and the second DC power supply is input to the second input terminal, so that the second DC power supply outputs the power supply through the output terminal.

6. A microgrid and energy storage system, characterized in that: It comprises a battery module, a control management module, a photovoltaic module, a wind power module, an energy storage converter and a power supply conversion circuit for uninterruptible power supply as claimed in any one of claims 1 to 5, wherein the energy storage converter is respectively connected to the power grid, the photovoltaic module, the wind power module, the power supply conversion circuit for uninterruptible power supply and the control management module, the power supply conversion circuit for uninterruptible power supply is also connected to the battery module, the control management module and the power grid, and the power grid is also connected to a load; The uninterruptible power supply conversion circuit is used to obtain power from the battery module or the power grid and convert it into power supply; The control management module is used to output a switch control signal after power-on to control the on / off of the switch module of the power supply conversion circuit of the uninterruptible power supply, and output a power supply control signal to control the energy storage inverter to perform bidirectional power supply conversion output and / or on / off.

7. The microgrid and energy storage system according to claim 6, characterized in that: The control management module includes: A battery management module, connected to the uninterruptible power supply conversion circuit and the battery module, the battery management module is used to obtain the power of the battery module when powered on and perform battery management; The host computer is respectively connected to the redundant power supply circuit of the power supply conversion circuit of the uninterruptible power supply, the battery management module, the energy storage inverter and the switch module of the power supply conversion circuit of the uninterruptible power supply, and is used to obtain power grid information through the energy storage inverter and obtain power information of the battery module through the battery management module when power is turned on, and output the switch control signal based on the power grid information and the power information to control the on and off of the switch module, and output the power control signal to control the energy storage inverter to perform bidirectional power conversion output and / or on and off.

8. The microgrid and energy storage system according to claim 7, characterized in that: The host computer is specifically used for: Upon receiving the grid information indicating a power outage in the grid, acquiring power information of the battery module; When the power of the battery module is greater than a preset value, switch to the black start mode, output a switch signal to control the switch module to be turned on, and output a power control signal to control the energy storage inverter to convert the DC power of the battery module into AC power and output it to the power grid and the load, or control the energy storage inverter to output the power of the photovoltaic module and / or wind power module to the power grid and / or the load; And when the power of the battery module is less than a preset value, the output power control signal controls the energy storage converter to stop working, or, when the power of the battery module is less than a preset value, controls the energy storage converter to output the power of the photovoltaic module and / or wind power module to the power grid and / or load; Upon receiving grid information indicating that the load power supply of the load is less than a preset load power supply, controlling the energy storage converter to output the electric energy of the photovoltaic module and / or wind power module to the grid and / or the load; When grid information indicating initial grid connection or grid restoration of the grid is received, the power control signal is output to control the energy storage converter to convert the AC power of the grid into DC power, and output it to the battery module through the switch module.

9. The microgrid and energy storage system according to claim 8, characterized in that: The energy storage converter is a three-phase four-wire energy storage converter; 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.

10. The microgrid and energy storage system according to claim 7, characterized in that: The control management module also includes: A smoke sensing system, connected to the uninterruptible power supply conversion circuit, for performing smoke sensing protection when powered on; A fire protection system, connected to the power supply conversion circuit of the uninterruptible power supply, for performing fire protection work when power is on; A water immersion system, connected to the power supply conversion circuit of the uninterruptible power supply, for performing water immersion protection work when power is turned on; A temperature system, connected to the power supply conversion circuit of the uninterruptible power supply, for performing temperature detection when power is turned on; The combustible gas detection system is connected to the power supply conversion circuit of the uninterruptible power supply and is used for performing combustible gas detection work when power is turned on.

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