An energy storage system based on distributed photovoltaic power generation

Abstract

The present invention relates to an energy storage system based on distributed photovoltaic power generation, and further includes an equalization controller, a double-pole double-throw switch, a grounding resistor, an exclusive-OR gate circuit, an AND gate circuit, and a switching transistor. The switching transistor is disposed between the equalization module and the battery module. The first set of contacts of the double-pole double-throw switch is disposed between the battery module and the output circuit. The common terminal of the second set of contacts is connected to a first power supply, and the normally open terminals are respectively connected to one end of the grounding resistor and the first input terminal of the exclusive-OR gate circuit. The other end of the grounding resistor is grounded. The second input terminal of the exclusive-OR gate circuit is connected to the first output pin of the equalization controller. The first input terminal of the AND gate circuit is connected to the output terminal of the exclusive-OR gate circuit, the second input terminal is connected to the first output pin of the controller, and the output terminal is connected to the control signal input terminal of the switching transistor. Compared with the prior art, the present invention has the advantages of improving reliability and the like.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic power generation, and in particular to an energy storage system based on distributed photovoltaic power generation. Background Art

[0002] Green power refers to the conversion of renewable energy such as wind energy and solar energy into electrical energy by using specific power generation equipment, such as wind turbines and solar photovoltaic cells. Compared with conventional thermal power generation - that is, obtaining electricity by burning fossil fuels such as coal, oil, and natural gas, electricity from renewable energy is more conducive to environmental protection and sustainable development. The research on the development strategy and operation management of green power is particularly important under the background of the increasingly prominent contradiction between human development and environmental protection.

[0003] The access of new energy will bring many uncertain factors (such as the time-varying nature of new energy power generation, etc.), so it will face the risk of cost volatility when formulating power generation dispatching plans and demand-side power system planning, and it is also not conducive to the safe and stable operation of the power system.

[0004] At present, the cost of photovoltaic power generation has been significantly reduced, and the average power generation cost is even lower than that of coal-fired power generation. Therefore, photovoltaic power generation has been gradually emphasized due to its low cost. However, the time constraint of photovoltaic power generation is still very serious. Photovoltaic cannot be used at night and on rainy days, and the time series characteristics of its power generation during the day may not necessarily match the power consumption curve. Therefore, it can only be coordinated by dispatching peak-shaving units. Due to the discrete characteristics of photovoltaic power generation, the aggregation and processing of this information will consume a large amount of resources and there is a huge coordination difficulty.

[0005] To solve the above problems, some existing technologies adopt a distributed energy storage system, allowing each distributed energy storage power supply to perform peak shaving and valley filling for its corresponding photovoltaic power generation device, thereby reducing the burden on the grid side. However, in this mode, the switching of the energy storage power supply is more frequent, and the startup of the balancing module may conflict with the output. Therefore, an avoidance logic is required. The traditional method directly realizes avoidance through a controller. Although the cost is low, the reliability is not high. Summary of the Invention

[0006] The purpose of the present invention is to provide an energy storage system based on distributed photovoltaic power generation, which realizes the interlock of the battery module and the balancing module in a pure hardware manner through a double-pole double-throw switch, a grounding resistor, an exclusive-OR gate circuit, an AND gate circuit, and a switching tube, thereby improving the reliability.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] An energy storage system based on distributed photovoltaic power generation, comprising a plurality of energy storage devices corresponding to each photovoltaic power generation device one by one. The energy storage device includes a battery module, a balancing module and an output circuit. The battery module is connected to a load through the output circuit, and the balancing module is connected to the battery module;

[0009] The device further includes a balancing controller, a double-pole double-throw switch, a grounding resistor, an exclusive-OR gate circuit, an AND gate circuit and a switching transistor. The switching transistor is disposed between the balancing module and the battery module. The first set of contacts of the double-pole double-throw switch is disposed between the battery module and the output circuit. The common terminal of the second set of contacts is connected to a first power supply, and the normally open terminals are respectively connected to one end of the grounding resistor and the first input terminal of the exclusive-OR gate circuit. The other end of the grounding resistor is grounded. The second input terminal of the exclusive-OR gate circuit is connected to the first output pin of the balancing controller. The first input terminal of the AND gate circuit is connected to the output terminal of the exclusive-OR gate circuit, the second input terminal is connected to the first output pin of the controller, and the output terminal is connected to the control signal input terminal of the switching transistor.

[0010] The double-pole double-throw switch is a relay.

[0011] A plurality of the battery modules and the balancing modules are provided. The double-pole double-throw switch, the grounding resistor, the exclusive-OR gate circuit, the AND gate circuit and the switching transistor form an interlock control module. The number of the interlock control modules is the same as the number of the battery modules, and the second input terminal of the exclusive-OR gate circuit and the second input terminal of the AND gate circuit of the second interlock control module are connected to the second output pin of the interlock control module.

[0012] Two of the battery modules and the balancing modules are provided.

[0013] The balancing controller is a single-chip microcomputer.

[0014] The voltage of the first power supply is 5V.

[0015] The grounding resistor is at least 10KΩ.

[0016] The relay is a DC relay.

[0017] The normally closed terminal of the second set of contacts of the double-pole double-throw switch is left open.

[0018] The battery module is a lithium battery pack.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. Through the double-pole double-throw switch, the grounding resistor, the exclusive-OR gate circuit, the AND gate circuit and the switching transistor, the interlock of the battery module and the balancing module is realized in a pure hardware manner, improving the reliability.

[0021] 2. The double-pole double-throw switch is a relay with a high withstand voltage rating and can support a larger power.

[0022] 3. The battery module has two groups and can output continuously. Description of the Drawings

[0023] Figure 1 It is a schematic circuit diagram of the interlock control part of the present invention;

[0024] Figure 2 It is a schematic diagram of the output pins of the equalization controller;

[0025] Figure 3 It is a schematic diagram of the energy storage system;

[0026] Among them: 1. Battery module, 2. Output circuit, K1. Double-pole double-throw switch, U0. Positive pole output by the battery module, VCC. First power supply, R1. Grounding resistor, V1. Exclusive-OR gate circuit, V2. AND gate circuit, S1. Switch tube, U1. Equalization controller, K1A. First group of contacts of the double-pole double-throw switch. Detailed Embodiment

[0027] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0028] An energy storage system based on distributed photovoltaic power generation includes a plurality of energy storage devices corresponding one by one to each photovoltaic power generation device, such as Figure 3 shown, the energy storage device includes a battery module 1, an equalization module and an output circuit 2. The battery module 1 is connected to the load through the output circuit 2, and the equalization module is connected to the battery module 1; under normal circumstances, the equalization module is responsible for capacity equalization of each battery string in the battery module 1. The battery module 1 is a lithium battery pack, which is the same as in the prior art. The battery module 1 needs to cooperate with the power generation balance of the photovoltaic module to output the power within a certain range. When the battery module 1 charges and discharges externally through the output circuit 2, the equalization module cannot equalize the battery module 1 at this time.

[0029] Such as Figure 1As shown, the device further includes an equalization controller U1, a double-pole double-throw switch K1, a grounding resistor R1, an exclusive-OR gate circuit V1, an AND gate circuit V2, and a switching transistor S1. The switching transistor S1 is disposed between the equalization module and the battery module 1. The first set of contacts of the double-pole double-throw switch K1 is disposed between the battery module 1 and the output circuit 2. The common terminal of the second set of contacts is connected to the first power supply VCC. The normally open ends are respectively connected to one end of the grounding resistor R1 and the first input terminal of the exclusive-OR gate circuit V1. The other end of the grounding resistor R1 is grounded. The second input terminal of the exclusive-OR gate circuit V1 is connected to the first output pin of the equalization controller U1. The first input terminal of the AND gate circuit V2 is connected to the output terminal of the exclusive-OR gate circuit V1. The second input terminal is connected to the first output pin of the controller. The output terminal is connected to the control signal input terminal of the switching transistor S1.

[0030] Through the double-pole double-throw switch K1, the grounding resistor R1, the exclusive-OR gate circuit V1, the AND gate circuit V2, and the switching transistor S1, the interlock between the battery module 1 and the equalization module is realized in a purely hardware manner, improving reliability.

[0031] Specifically, when the double-pole double-throw switch K1 is disconnected, the normally open ends of both sets of contacts of K1 are disconnected. At this time, the voltage at the non-grounded end of R1 is low. At this time, under normal circumstances, the first output pin of the equalization controller U1 is low, the output of the exclusive-OR gate is low, the output of the AND gate is low, and the switching transistor S1 is not turned on. If the equalization module reaches the preset time for equalization, at this time, the first output pin of the equalization controller U1 outputs high, the output of the exclusive-OR gate is high, and since the first output pin of the equalization controller U1 is high, both inputs of the AND gate are high, then the output of the AND gate is high, and the switching transistor S1 is turned on to start equalization.

[0032] On the contrary, when the double-pole double-throw switch K1 is closed, the normally open ends of both sets of contacts of K1 are closed. At this time, the voltage at the non-grounded end of R1 is high. At this time, under normal circumstances, the first output pin of the equalization controller U1 is low, the output of the exclusive-OR gate is high, but since the first output pin of the equalization controller U1 is low, the output of the AND gate is still low, and the switching transistor S1 is not turned on. If the equalization module reaches the preset time for equalization, at this time, the first output pin of the equalization controller U1 outputs high, the output of the exclusive-OR gate is low. Therefore, although the first output pin of the equalization controller U1 is high, the other input of the AND gate is low, so the switching transistor S1 is not turned on. The detailed logic is shown in Table 1:

[0033] Table 1

[0034]

[0035] In this way, the interlock control is completed through the hardware circuit.

[0036] In this embodiment, the double-pole double-throw switch K1 is a relay, which has a high withstand voltage level and can support a larger power. Preferably, the relay is a DC relay.

[0037] In some embodiments, there are multiple battery modules 1 and balancing modules. The double-pole double-throw switch K1, the grounding resistor R1, the exclusive-OR gate circuit V1, the AND gate circuit V2, and the switching transistor S1 form an interlock control module. The number of interlock control modules is the same as the number of battery modules 1. And the second input terminal of the exclusive-OR gate circuit V1 and the second input terminal of the AND gate circuit V2 of the second interlock control module are connected to the second output pin of the interlock control module. In this embodiment, there are two battery modules 1 and balancing modules, which are used as backups for each other. In this way, they can work alternately to maintain a good working state.

[0038] In this embodiment, the balancing controller U1 is a single-chip microcomputer, and Q1 to Q3 are three output pins respectively.

[0039] In some embodiments, the voltage of the first power supply VCC is 5V. In addition, the resistance value of the grounding resistor R1 should be large enough to reduce power consumption and maintain the high level on the non-grounded side of R1 when the double-pole double-throw switch K1 is closed. The grounding resistor R1 is at least 10KΩ.

[0040] In this embodiment, the normally-closed end of the second set of contacts of the double-pole double-throw switch K1 is left open, making the wiring simpler.

Claims

1. A energy storage system based on distributed photovoltaic power generation, comprising a plurality of energy storage devices corresponding to each photovoltaic power generation device one by one. The energy storage device includes a battery module, a balancing module and an output circuit. The battery module is connected to a load through the output circuit, and the balancing module is connected to the battery module; It is characterized in that The device further includes a balancing controller, a double-pole double-throw switch, a grounding resistor, an exclusive-OR gate circuit, an AND gate circuit and a switching tube. The switching tube is disposed between the balancing module and the battery module. The first set of contacts of the double-pole double-throw switch is disposed between the battery module and the output circuit. The common terminal of the second set of contacts is connected to a first power supply, and the normally open terminals are respectively connected to one end of the grounding resistor and the first input terminal of the exclusive-OR gate circuit. The other end of the grounding resistor is grounded. The second input terminal of the exclusive-OR gate circuit is connected to the first output pin of the balancing controller. The first input terminal of the AND gate circuit is connected to the output terminal of the exclusive-OR gate circuit, the second input terminal is connected to the first output pin of the balancing controller, and the output terminal is connected to the control signal input terminal of the switching tube; A plurality of the battery modules and the balancing modules are provided. The double-pole double-throw switch, the grounding resistor, the exclusive-OR gate circuit, the AND gate circuit and the switching tube form an interlocking control module. The number of the interlocking control modules is the same as the number of the battery modules, and the second input terminal of the exclusive-OR gate circuit and the second input terminal of the AND gate circuit of the second interlocking control module are connected to the second output pin of the interlocking control module.

2. The energy storage system based on distributed photovoltaic power generation according to claim 1, wherein The double-pole double-throw switch is a relay.

3. A energy storage system based on distributed photovoltaic power generation according to claim 1, characterized in that, Two battery modules and two balancing modules are provided.

4. The energy storage system based on distributed photovoltaic power generation according to claim 1, wherein The balancing controller is a single-chip microcomputer.

5. A energy storage system based on distributed photovoltaic power generation according to claim 1, wherein, The voltage of the first power supply is 5V.

6. The energy storage system based on distributed photovoltaic power generation according to claim 1, wherein The grounding resistor is at least 10KΩ.

7. A energy storage system based on distributed photovoltaic power generation according to claim 2, characterized in that, The relay is a DC relay.

8. A energy storage system based on distributed photovoltaic power generation according to claim 1, characterized in that, The normally closed terminal of the second set of contacts of the double-pole double-throw switch is left open.

9. An energy storage system based on distributed photovoltaic power generation according to claim 1, characterized in that, The battery module is a lithium battery pack.

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