CN116388117A - Overvoltage and undervoltage protector and energy storage system - Google Patents

Abstract

The embodiment of the application discloses cross undervoltage protection ware and energy storage system, it crosses undervoltage protection ware and includes: an over-voltage and under-voltage protector body; at least two switches, each of which is integrated on the overvoltage and undervoltage protector body; wherein, at least two loads are connected in parallel on the power grid after being connected with one switch in series; when the power grid is in an under-voltage or over-voltage state, the loads and the power grid are disconnected simultaneously through the corresponding switches. According to the method, an independent overvoltage and undervoltage protector is not required to be connected in series on each load, so that the on-off of each load on the power grid can be realized, the bulkiness of the power grid is reduced, the cost is saved, and the stability of the power grid is improved.

Description

Overvoltage and undervoltage protector and energy storage system

Technical Field

The application relates to the technical field of energy storage, in particular to an overvoltage and undervoltage protector and an energy storage system.

Background

The overvoltage and undervoltage protector is a device for protecting a load by switching off power when the voltage in a circuit exceeds a permissible range. In general, a plurality of loads are connected in parallel on a line, as shown in fig. 1, in order to prevent a loop from being formed between the loads after the loads are disconnected, each load on the line needs to be connected in parallel on a main line after being connected in series with an independent overvoltage-undervoltage protector a, an independent overvoltage-undervoltage protector B and an independent overvoltage-undervoltage protector C respectively. However, the above manner inevitably results in a large number of components on the circuit, which is very likely to cause the circuit to be bulky.

Disclosure of Invention

Aiming at the defects of the prior art, the application provides an overvoltage and undervoltage protector and an energy storage system, which reduce the number of components on a circuit, save the cost and improve the stability of the circuit.

To solve the above-mentioned problem, in a first aspect, an embodiment of the present application provides an overvoltage/undervoltage protector, which includes:

an over-voltage and under-voltage protector body;

at least two switches, each of which is integrated on the overvoltage and undervoltage protector body;

wherein, at least two loads are connected in parallel on the power grid after being connected with one switch in series; when the power grid is in an under-voltage or over-voltage state, the loads and the power grid are disconnected simultaneously through the corresponding switches.

Further, in the overvoltage/undervoltage protector, at least one load is used as an energy storage module, when the power grid is in an undervoltage or overvoltage state, the loads and the power grid are disconnected simultaneously through the corresponding switches, and the energy storage module and the loads of other non-energy storage modules are conducted through the corresponding switches so as to supply power to the loads of the other non-energy storage modules by the energy storage module.

Furthermore, in the overvoltage and undervoltage protector, the energy storage module is a photovoltaic energy storage module.

Further, in the overvoltage and undervoltage protector, the photovoltaic energy storage module comprises a photovoltaic inverter, a photovoltaic panel and a battery;

the photovoltaic inverter comprises a grid-connected port, a PV port and a battery port, wherein the grid-connected port is electrically connected with the switch, the photovoltaic panel is electrically connected with the photovoltaic inverter through the PV port, and the battery is electrically connected with the photovoltaic inverter through the battery port.

Further, in the over-voltage and under-voltage protector, the switch integrated on the over-voltage and under-voltage protector body comprises a first bidirectional thyristor switch and a second bidirectional thyristor switch, and the over-voltage and under-voltage protector body is provided with a controller;

the gate G and the main electrode T2 of the first bidirectional thyristor switch are electrically connected with the power grid through the controller, and the main electrode T1 is electrically connected with the load; the gate G of the second bidirectional thyristor switch is electrically connected with the power grid, the main electrode T1 is electrically connected with the power grid and is electrically connected with the energy storage module through the load, and the main electrode T2 is electrically connected with the energy storage module.

Further, in the overvoltage/undervoltage protector, the power source provided by the power grid for the load is single-phase alternating current or three-phase alternating current.

Furthermore, in the overvoltage/undervoltage protector, a rectifying filter is arranged at a power supply end of the power grid for providing the load.

Further, in the overvoltage/undervoltage protector, the rectifying filter includes a diode VD1, a diode VD2, a capacitor C1, and a capacitor C2;

the positive electrode of the diode VD1 is connected with the N end of the alternating current, and the negative electrode of the diode VD2 is connected with the positive electrode of the diode VD2 and is connected with the L end of the alternating current through the capacitor C1; one end of the capacitor C2 is connected with the cathode of the diode VD2, and the other end of the capacitor C2 is respectively connected with the N end of the alternating current and the anode of the diode VD 1.

In a second aspect, embodiments of the present application also provide an energy storage system, including:

a power grid;

a plurality of energy storage modules and a load;

the overvoltage and undervoltage protector comprises an overvoltage and undervoltage protector body and at least two switches, wherein each switch is integrated on the overvoltage and undervoltage protector body;

the energy storage modules and the loads are connected in parallel on the power grid, and at least one energy storage module and at least one load are connected in series with one switch independently and then connected in parallel on the power grid;

when the power grid is in an undervoltage or overvoltage state, the energy storage module, the load and the power grid are disconnected simultaneously through the corresponding switches, and the energy storage module and the load are conducted through the corresponding switches so as to supply power to the load.

Further, in the energy storage system, the energy storage module is a photovoltaic energy storage module.

The overvoltage and undervoltage protector provided by the embodiment of the application comprises an overvoltage and undervoltage protector body and at least two switches, wherein each switch is integrated on the overvoltage and undervoltage protector body, and at least two loads corresponding to the number of the switches are connected in series with one switch respectively and then connected to a power grid in parallel, so that when the power grid is in an undervoltage or overvoltage state, each load and the power grid can be disconnected simultaneously through the corresponding switch. According to the method, an independent overvoltage and undervoltage protector is not required to be connected in series on each load, so that the on-off of each load on the power grid can be realized, the bulkiness of the power grid is reduced, the cost is saved, and the stability of the power grid is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic circuit diagram of a prior art power grid with an over-voltage and under-voltage protector;

fig. 2 is a schematic circuit diagram of a power grid provided with an overvoltage/undervoltage protector according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a prior art energy storage system with an over-voltage and under-voltage protector;

FIG. 4 is a schematic circuit diagram of an energy storage system provided with an over-voltage and under-voltage protector according to an embodiment of the present application;

FIG. 5 is another schematic circuit diagram of an energy storage system with an over-voltage and under-voltage protector according to an embodiment of the present disclosure;

FIG. 6 is another schematic circuit diagram of an energy storage system with an over-voltage and under-voltage protector according to an embodiment of the present disclosure;

fig. 7 is another schematic circuit diagram of an energy storage system provided with an overvoltage/undervoltage protector according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

It should be understood that the terms "comprises" and "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

As the background technology of the application analyzes, the number of components on the existing circuit is large, the circuit is very easy to be bulked, and the overvoltage and undervoltage protector is provided for solving the technical problems.

Referring to fig. 2, fig. 2 is a schematic circuit diagram of a power grid provided with an overvoltage/undervoltage protector according to an embodiment of the present application.

As shown in fig. 2, an over-voltage and under-voltage protector includes:

an over-voltage and under-voltage protector body;

at least two switches, each of which is integrated on the overvoltage and undervoltage protector body;

wherein, at least two loads are connected in parallel on the power grid after being connected with one switch in series; when the power grid is in an under-voltage or over-voltage state, the loads and the power grid are disconnected simultaneously through the corresponding switches.

In the specific embodiment shown in fig. 2, the switch K1, the switch K2 and the switch K3 are integrated on the overvoltage/undervoltage protector body to form the overvoltage/undervoltage protector D in fig. 2, and the overvoltage/undervoltage protector body is provided with devices for automatically controlling the on/off of the switches simultaneously, that is, the overvoltage/undervoltage protector body can automatically control the on/off of the switch K1, the switch K2 and the switch K3, so as to realize the on/off of the load 1, the load 2 and the load 3.

In this embodiment, the switch K1, the switch K2, and the switch K3 each include a first end and a second end, the first ends of the switch K1, the switch K2, and the switch K3 are all electrically connected to the power grid, and the second ends of the switch K1, the switch K2, and the switch K3 are respectively connected to a load. When the power grid is in an undervoltage or overvoltage state, the switch K1, the switch K2 and the first end and the second end of the switch K3 in the overvoltage/undervoltage protector are in an off state, that is, the current in the power grid cannot flow to the corresponding second end through the first ends of the switch K1, the switch K2 and the switch K3.

It is understood that the switches K1, K2 and K3 may be formed by components such as diodes, triodes, MOS transistors, etc., and the specific connection manner thereof may be selected according to practical applications, which is not limited in this embodiment.

The overvoltage and undervoltage protector provided by the embodiment of the application comprises an overvoltage and undervoltage protector body and at least two switches, wherein each switch is integrated on the overvoltage and undervoltage protector body, at least two loads corresponding to the number of the switches are connected in parallel on a power grid, one switch is arranged between each load and the power grid, and then when the power grid is in an undervoltage or overvoltage state, the switches corresponding to each load and the power grid can be disconnected simultaneously. According to the method, an independent overvoltage and undervoltage protector is not required to be connected in series on each load, so that the on-off of each load on the power grid can be realized, the bulkiness of the power grid is reduced, the cost is saved, and the stability of the power grid is improved.

In some embodiments, the overvoltage and undervoltage protector provided by the application can be applied to an energy storage system, especially to a photovoltaic energy storage system, that is, at least one load of a plurality of loads in the energy storage system can supply power to other loads, and the overvoltage and undervoltage protector can be used as an energy storage module. When the energy storage module is a photovoltaic energy storage module, it may be composed of a photovoltaic inverter PCS, a photovoltaic panel and a battery. When the power grid is in an under-voltage or over-voltage state, the loads and the power grid are disconnected simultaneously through the corresponding switches, and the energy storage modules and the loads of other non-energy storage modules are conducted through the corresponding switches so as to supply power to the loads of the other non-energy storage modules.

As shown in fig. 3, when the existing under-voltage protector is applied to a photovoltaic energy storage system, the photovoltaic inverter PCS, the load and the ac contactor are all required to be separately connected in series with an independent over-voltage protector a, an independent over-voltage protector B and an independent over-voltage protector C, and then are connected in parallel with a power grid, a switch K1 is arranged in the over-voltage protector a, a switch K2 is arranged in the over-voltage protector B, a switch K3 is arranged in the over-voltage protector C, the switch K1 controls the on-off of the photovoltaic inverter PCS in the mains voltage, the switch K2 controls the on-off of the load in the mains voltage, and the switch K3 controls the on-off of the ac contactor in the mains voltage. The photovoltaic inverter PCS is provided with four ports, namely a power grid port, a standby power supply port, a PV port and a battery port, wherein the power grid port is used for receiving commercial power to normally provide power, the standby power supply port is used for providing power to avoid load outage when the commercial power voltage exceeds a permissible range, the PV port is used for receiving solar energy collected by a photovoltaic panel, and the battery port is used for storing electric energy converted by the photovoltaic panel through the inverter so as to provide power input through the standby power supply port. If the power grid cannot supply power to the load, for example, when the voltage in the power grid is not in the range of 150V-270V, a switch K1 in the overvoltage-undervoltage protector A, a switch K2 in the overvoltage-undervoltage protector B and a switch K3 in the overvoltage-undervoltage protector C are all disconnected, and meanwhile, an alternating current contactor conducts a PCS and the load through a relay, and the photovoltaic inverter PCS supplies power to the load in the photovoltaic energy storage system through a standby power port. However, the photovoltaic energy storage system provided by the above is complex in topological structure, high in failure rate and poor in reliability.

In order to solve the technical problem, the application provides an overvoltage and undervoltage protector applied to a photovoltaic energy storage system. Referring to fig. 4, fig. 5, and fig. 6, fig. 4 is a schematic circuit diagram of an energy storage system provided with an overvoltage/undervoltage protector according to an embodiment of the present application; FIG. 5 is another schematic circuit diagram of an energy storage system with an over-voltage and under-voltage protector according to an embodiment of the present disclosure; fig. 6 is another schematic circuit diagram of an energy storage system provided with an overvoltage/undervoltage protector according to an embodiment of the present application.

As shown in fig. 4, 5 and 6, the photovoltaic energy storage system includes a power grid, an overvoltage/undervoltage protector D, a photovoltaic inverter PCS, a load, a photovoltaic panel and a battery. The power provided by the power grid can be single-phase alternating current, the circuit topology diagram of the photovoltaic energy storage system is shown in fig. 5, the power provided by the power grid can be three-phase alternating current, and the circuit topology diagram of the photovoltaic energy storage system is shown in fig. 6.

In this embodiment, the overvoltage and undervoltage protector D is composed of an overvoltage and undervoltage protector body, a switch K1 and a switch K2, the switch K1 and the switch K2 are integrated on the overvoltage and undervoltage protector body, meanwhile, an ac contactor in the photovoltaic energy storage system can also be directly integrated on the overvoltage and undervoltage protector body (not shown in the figure), and then the ac contactor and a load are not required to be connected in parallel on a power grid at the same time, so that the parts of the photovoltaic energy storage system are greatly reduced, the cost is saved, and meanwhile, the stability of the photovoltaic energy storage system is also improved. The switch K1 and the switch K2 comprise a first end, a second end and a third end, the photovoltaic inverter PCS comprises three ports which are a grid-connected port, a PV port and a battery port respectively, wherein the grid-connected port can be obtained by integrating a standby power port and a power grid port, so that wiring harnesses are saved, and the redundancy and the failure rate of the system are reduced.

Specifically, when the power supply provided by the power grid is single-phase alternating current, the first ends of the switch K1 and the switch K2 are respectively and electrically connected with a live wire L and a zero wire N in the power grid; when the power supply provided by the power grid is three-phase alternating current, the first ends of the switch K1 and the switch K2 are respectively and electrically connected with a live wire L1, a live wire L2, a live wire L3 and a zero line N in the power grid; the second end of the switch K1 is electrically connected with the grid-connected port of the photovoltaic inverter PCS, the second end of the switch K2 is connected with the load, and the switch K1 and the third end of the switch K2 are connected in series, so that the switch K1 can control the on-off of the photovoltaic inverter PCS in the mains voltage, and the switch K2 can control the on-off of the load in the mains voltage. In addition, the photovoltaic panel is electrically connected with the photovoltaic inverter through the PV port, and the battery is electrically connected with the photovoltaic inverter through the battery port.

In the embodiments shown in fig. 4 and fig. 5, when the utility grid supplying power to the photovoltaic energy storage system is in an under-voltage or over-voltage state, the switch K1 on the over-voltage protector and the first end and the second end on the switch K2 are disconnected, so that the power supply of the utility grid to the photovoltaic inverter PCS and the load can be disconnected, and meanwhile, the switch K1 on the over-voltage protector and the second end and the third end on the switch K2 are conducted, so that the battery in the photovoltaic energy storage system supplies power to the load, and the uninterrupted power of the load when the utility grid is in the under-voltage or over-voltage state is ensured.

In some embodiments, the present application also provides an energy storage system comprising:

a power grid;

a plurality of energy storage modules and a load;

the overvoltage and undervoltage protector comprises an overvoltage and undervoltage protector body and at least two switches, wherein each switch is integrated on the overvoltage and undervoltage protector body;

the energy storage modules and the loads are connected in parallel on the power grid, and at least one energy storage module and at least one load are connected in series with one switch independently and then connected in parallel on the power grid;

when the power grid is in an undervoltage or overvoltage state, the energy storage module, the load and the power grid are disconnected simultaneously through the corresponding switches, and the energy storage module and the load are conducted through the corresponding switches so as to supply power to the load.

Specifically, at least one load of the plurality of loads in the energy storage system may supply power to the other loads, which may be referred to as an energy storage module. When the energy storage module is a photovoltaic energy storage module, it may be composed of a photovoltaic inverter PCS, a photovoltaic panel and a battery. When the power grid is in an under-voltage or over-voltage state, the loads and the power grid are disconnected simultaneously through the corresponding switches, and the energy storage modules and the loads of other non-energy storage modules are conducted through the corresponding switches so as to supply power to the loads of the other non-energy storage modules.

In some embodiments, as shown in fig. 7, the energy storage system is a photovoltaic energy storage system, the power provided by the power grid is single-phase alternating current, the switch integrated on the overvoltage and undervoltage protector body comprises a first triac VS1 and a second triac VS2, and the overvoltage and undervoltage protector body is provided with a controller; the gate electrode G and the main electrode T2 of the first bidirectional thyristor switch VS1 are electrically connected with the power grid through the controller, and the main electrode T1 is electrically connected with the load; the gate G of the second bidirectional thyristor switch VS2 is electrically connected with the power grid, the main electrode T1 is electrically connected with the power grid and is electrically connected with the photovoltaic energy storage module through the load, and the main electrode T2 is electrically connected with the photovoltaic energy storage module.

Specifically, when the voltage of the power grid is in a normal state, the main electrode T1 of the first triac VS1 is an anode, and the main electrode T2 of the first triac VS1 is a cathode, that is, the first triac VS1 is in a conductive state; the main electrode T1 of the second triac VS2 is a cathode, and the main electrode T2 of the second triac VS2 is an anode, that is, the second triac VS2 is in an off state; when the voltage of the power grid is in an undervoltage or overvoltage state, the main electrode T1 of the first bidirectional thyristor switch VS1 is a cathode, and the main electrode T2 of the first bidirectional thyristor switch VS1 is an anode, that is to say, the first bidirectional thyristor switch VS1 is in an off state; the main electrode T1 of the second triac VS2 is an anode, and the main electrode T2 of the second triac VS2 is a cathode, that is, the second triac VS2 is in an on state.

In some embodiments, as shown in fig. 7, a rectifying filter E is disposed at a power end of the power grid for providing the load. Specifically, by arranging the rectifying filter E at the power end of the power grid for providing the load, the alternating current at the power end can be converted into direct current, and further, the load in the photovoltaic energy storage system is powered.

In the specific embodiment shown in fig. 7, the rectifying filter E includes a diode VD1, a diode VD2, a capacitor C1, and a capacitor C2; the positive electrode of the diode VD1 is connected with the N end of the alternating current, and the negative electrode of the diode VD2 is connected with the positive electrode of the diode VD2 and is connected with the L end of the alternating current through the capacitor C1; one end of the capacitor C2 is connected with the cathode of the diode VD2, and the other end of the capacitor C2 is respectively connected with the N end of the alternating current and the anode of the diode VD 1.

The overvoltage and undervoltage protector and the energy storage system provided by the embodiment of the application are characterized in that the overvoltage and undervoltage protector is composed of an overvoltage and undervoltage protector body and at least two switches, each switch is integrated on the overvoltage and undervoltage protector body, at least two loads corresponding to the number of the switches are connected in parallel on a power grid, one switch is arranged between each load and the power grid, and when the power grid is in an undervoltage or overvoltage state, the switches corresponding to the switches between each load and the power grid can be simultaneously disconnected. According to the method, an independent overvoltage and undervoltage protector is not required to be connected in series on each load, so that the on-off of each load on the power grid can be realized, the bulkiness of the power grid is reduced, the wire harness in the circuit is reduced, the cost is saved, and the stability of the power grid is improved.

While the invention has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. An over-voltage and under-voltage protector, comprising:

an over-voltage and under-voltage protector body;

at least two switches, each of which is integrated on the overvoltage and undervoltage protector body;

wherein, at least two loads are connected in parallel on the power grid after being connected with one switch in series; when the power grid is in an under-voltage or over-voltage state, the loads and the power grid are disconnected simultaneously through the corresponding switches.

2. The overvoltage/undervoltage protector of claim 1, wherein at least one of the loads is used as an energy storage module, when the power grid is in an undervoltage or overvoltage state, each of the loads and the power grid are simultaneously disconnected through the corresponding switch, and the energy storage module and the loads of other non-energy storage modules are conducted through the corresponding switches so as to supply power to the loads of the other non-energy storage modules by the energy storage module.

3. The over-voltage and under-voltage protector of claim 2, wherein the energy storage module is a photovoltaic energy storage module.

4. The over-voltage and under-voltage protector of claim 3, wherein the photovoltaic energy storage module comprises a photovoltaic inverter, a photovoltaic panel, and a battery;

the photovoltaic inverter comprises a grid-connected port, a PV port and a battery port, wherein the grid-connected port is electrically connected with the switch, the photovoltaic panel is electrically connected with the photovoltaic inverter through the PV port, and the battery is electrically connected with the photovoltaic inverter through the battery port.

5. The over-voltage and under-voltage protector according to claim 2, wherein the switch integrated on the over-voltage and under-voltage protector body comprises a first triac and a second triac, and the over-voltage and under-voltage protector body is provided with a controller;

the gate G and the main electrode T2 of the first bidirectional thyristor switch are electrically connected with the power grid through the controller, and the main electrode T1 is electrically connected with the load; the gate G of the second bidirectional thyristor switch is electrically connected with the power grid, the main electrode T1 is electrically connected with the power grid and is electrically connected with the energy storage module through the load, and the main electrode T2 is electrically connected with the energy storage module.

6. The over-voltage and under-voltage protector of claim 1, wherein the power source provided by the power grid to the load is single-phase alternating current or three-phase alternating current.

7. The overvoltage and undervoltage protector of claim 6, wherein the power grid is provided with a rectifying filter at a power supply end for the load.

8. The overvoltage and undervoltage protector of claim 7, wherein the rectifying filter includes a diode VD1, a diode VD2, a capacitor C1, and a capacitor C2;

the positive electrode of the diode VD1 is connected with the N end of the alternating current, and the negative electrode of the diode VD2 is connected with the positive electrode of the diode VD2 and is connected with the L end of the alternating current through the capacitor C1; one end of the capacitor C2 is connected with the cathode of the diode VD2, and the other end of the capacitor C2 is respectively connected with the N end of the alternating current and the anode of the diode VD 1.

9. An energy storage system, comprising:

a power grid;

a plurality of energy storage modules and a load;

the overvoltage and undervoltage protector comprises an overvoltage and undervoltage protector body and at least two switches, wherein each switch is integrated on the overvoltage and undervoltage protector body;

the energy storage modules and the loads are all connected in parallel on the power grid, and at least one energy storage module and at least one load are connected in series with one switch independently and then connected in parallel on the power grid;

when the power grid is in an undervoltage or overvoltage state, the energy storage module, the load and the power grid are disconnected simultaneously through the corresponding switches, and the energy storage module and the load are conducted through the corresponding switches so as to supply power to the load.

10. The energy storage system of claim 9, wherein the energy storage module is a photovoltaic energy storage module.

Images