Over / under voltage protectors and energy storage systems

Abstract

This application discloses an over / under voltage protector and an energy storage system. The over / under voltage protector includes: an over / under voltage protector body; at least two switches, each integrated on the over / under voltage protector body; wherein at least two loads are connected in parallel to the power grid after being connected in series with one of the switches; when the power grid is in an undervoltage or overvoltage state, each load is simultaneously disconnected from the power grid through its corresponding switch. This application eliminates the need for a separate over / under voltage protector connected in series with each load, thus enabling the switching of various loads on the power grid, reducing grid bulkiness, saving costs, and improving grid stability.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an over / under voltage protector and an energy storage system. Background Technology

[0002] An over / undervoltage protector is a device that cuts off power to the load when the voltage in a line exceeds the permissible range. Multiple loads are typically connected in parallel on a line, such as... Figure 1 As shown, to prevent loops from forming between loads after disconnection, each load on the line needs to be connected in parallel to the main line after being connected in series with an independent over / under voltage protector A, over / under voltage protector B, and over / under voltage protector C. However, this method inevitably leads to a large number of components on the line, easily causing the line to become bloated. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this application provides an over / under voltage protector and an energy storage system that reduces the number of components on the line, saves costs, and improves line stability.

[0004] To address the aforementioned problems, in a first aspect, embodiments of this application provide an over / under voltage protector, comprising:

[0005] Over / under voltage protector body;

[0006] At least two switches, each of which is integrated on the over / under voltage protector body;

[0007] In this configuration, at least two loads are connected in parallel to the power grid after being connected in series with a switch; when the power grid is in an undervoltage or overvoltage state, each load is simultaneously disconnected from the power grid through its corresponding switch.

[0008] Furthermore, in the over / under voltage protector, at least one of the loads serves as an energy storage module. When the power grid is in an undervoltage or overvoltage state, each load is simultaneously disconnected from the power grid through its corresponding switch. The energy storage module is connected to other non-energy storage module loads through its corresponding switch, so that the energy storage module can supply power to the other non-energy storage module loads.

[0009] Furthermore, in the over / under voltage protector, the energy storage module is a photovoltaic energy storage module.

[0010] Furthermore, in the aforementioned over / under voltage protector, the photovoltaic energy storage module includes a photovoltaic inverter, a photovoltaic panel, and a battery;

[0011] The photovoltaic inverter includes an off-grid port, a PV port, and a battery port. The off-grid port is electrically connected to the switch. The photovoltaic panel is electrically connected to the photovoltaic inverter through the PV port, and the battery is electrically connected to the photovoltaic inverter through the battery port.

[0012] Furthermore, in the over / under voltage protector, the switch integrated on the over / under voltage protector body includes a first bidirectional thyristor switch and a second bidirectional thyristor switch, and a controller is provided on the over / under voltage protector body.

[0013] In this configuration, the gate G and main electrode T2 of the first bidirectional thyristor switch are both electrically connected to the power grid through the controller, and the main electrode T1 is electrically connected to the load; the gate G of the second bidirectional thyristor switch is electrically connected to the power grid, the main electrode T1 is electrically connected to the power grid and is electrically connected to the energy storage module through the load, and the main electrode T2 is electrically connected to the energy storage module.

[0014] Furthermore, in the over / under voltage protector, the power supply provided by the power grid to the load is single-phase AC or three-phase AC.

[0015] Furthermore, in the over / under voltage protector, a rectifier filter is provided at the power supply terminal of the power grid for the load.

[0016] Furthermore, in the over / under voltage protector, the rectifier filter includes diode VD1, diode VD2, capacitor C1, and capacitor C2;

[0017] In this configuration, the positive terminal of diode VD1 is connected to the N terminal of the AC power supply, and the negative terminal is connected to the positive terminal of diode VD2 and connected to the L terminal of the AC power supply through capacitor C1; one end of capacitor C2 is connected to the negative terminal of diode VD2, and the other end is connected to the N terminal of the AC power supply and the positive terminal of diode VD1.

[0018] Secondly, embodiments of this application also provide an energy storage system, which includes:

[0019] Power grid;

[0020] Several energy storage modules and loads;

[0021] An over / under voltage protector includes an over / under voltage protector body and at least two switches, each of which is integrated on the over / under voltage protector body.

[0022] In this configuration, the energy storage module and the load are both connected in parallel to the power grid, and at least one energy storage module and at least one load are connected in series with a switch and then connected in parallel to the power grid.

[0023] When the power grid is in an undervoltage or overvoltage state, the energy storage module, the load and the power grid are simultaneously disconnected through their respective corresponding switches, and the energy storage module and the load are connected through their respective corresponding switches, so that the energy storage module can supply power to the load.

[0024] Furthermore, in the energy storage system, the energy storage module is a photovoltaic energy storage module.

[0025] The over / under voltage protector provided in this application consists of an over / under voltage protector body and at least two switches. Each switch is integrated into the over / under voltage protector body. Simultaneously, at least two loads corresponding to the number of switches are connected in parallel to the power grid via a separate switch connected in series. Therefore, when the power grid is in an under / overvoltage state, each load can be simultaneously disconnected from the power grid via its corresponding switch. This application eliminates the need for a separate over / under voltage protector connected in series with each load, thus achieving the switching of various loads on the power grid, reducing power grid bulkiness, saving costs, and improving power grid stability. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A circuit diagram of an existing power grid equipped with over / under voltage protection devices;

[0028] Figure 2 A circuit diagram of a power grid equipped with an over / under voltage protector is provided for an embodiment of this application.

[0029] Figure 3 A circuit diagram of an existing energy storage system equipped with over / under voltage protection;

[0030] Figure 4 A circuit diagram of an energy storage system with over / under voltage protection provided in the embodiments of this application;

[0031] Figure 5 Another circuit diagram of the energy storage system provided in this application embodiment, which includes an over / under voltage protector;

[0032] Figure 6 Another circuit diagram of the energy storage system provided in this application embodiment, which includes an over / under voltage protector;

[0033] Figure 7Another circuit diagram of the energy storage system provided in the embodiments of this application, which includes an over / under voltage protector. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0036] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope 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 unless the context clearly indicates otherwise.

[0037] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0038] As analyzed in the background section of this application, existing circuits have a large number of components, which can easily lead to bloated circuits. To solve the above-mentioned technical problems, this application provides an over / under voltage protector.

[0039] Please see Figure 2 , Figure 2 The circuit diagram of the power grid equipped with over / under voltage protection is provided for the embodiments of this application.

[0040] like Figure 2 As shown, an over / under voltage protector includes:

[0041] Over / under voltage protector body;

[0042] At least two switches, each of which is integrated on the over / under voltage protector body;

[0043] In this configuration, at least two loads are connected in parallel to the power grid after being connected in series with a switch; when the power grid is in an undervoltage or overvoltage state, each load is simultaneously disconnected from the power grid through its corresponding switch.

[0044] exist Figure 2 In the specific embodiment shown, switches K1, K2, and K3 are integrated on the over / under voltage protector body to form... Figure 2 The over / under voltage protector D in the middle is equipped with a device that automatically controls the simultaneous on / off of each switch. That is, the over / under voltage protector can automatically control the on / off of switches K1, K2 and K3, thereby realizing the on / off of load 1, load 2 and load 3.

[0045] In this embodiment, switches K1, K2, and K3 each include a first terminal and a second terminal. The first terminals of switches K1, K2, and K3 are all electrically connected to the power grid, and the second terminals of switches K1, K2, and K3 are each connected to a load. When the power grid is in an undervoltage or overvoltage state, the first and second terminals of switches K1, K2, and K3 in the overvoltage / undervoltage protector are in an open state, meaning that current in the power grid cannot flow from the first terminal of switches K1, K2, and K3 to the corresponding second terminal.

[0046] It is understood that switches K1, K2, and K3 can be composed of components such as diodes, transistors, and MOSFETs, and their specific connection methods can be selected according to actual applications. This embodiment does not impose specific limitations.

[0047] The over / under voltage protector provided in this application consists of an over / under voltage protector body and at least two switches. Each switch is integrated into the over / under voltage protector body. Simultaneously, at least two loads corresponding to the number of switches are connected in parallel to the power grid. Each load has a corresponding switch connected to the power grid. Therefore, when the power grid is in an under / overvoltage state, each load can be simultaneously disconnected from the power grid via its respective switch. This application eliminates the need for a separate over / under voltage protector connected in series with each load, thus enabling the switching of various loads on the power grid. This reduces the bulkiness of the power grid, saves costs, and improves the stability of the power grid.

[0048] In some embodiments, the over / under voltage protector provided in this application can be applied to energy storage systems, particularly photovoltaic energy storage systems. Specifically, in an energy storage system, at least one load among multiple loads can supply power to the others; this load can be an energy storage module. When the energy storage module is a photovoltaic energy storage module, it can consist of a photovoltaic inverter (PCS), photovoltaic panels, and batteries. When the power grid is in an undervoltage or overvoltage state, each load is simultaneously disconnected from the power grid via its corresponding switch, while the energy storage module is connected to other non-energy storage module loads via its corresponding switch, thus enabling the energy storage module to supply power to the other non-energy storage module loads.

[0049] like Figure 3 As shown, when existing undervoltage protectors are applied to photovoltaic energy storage systems, the photovoltaic inverter PCS, load, and AC contactor each need to be connected in series with an independent overvoltage / undervoltage protector A, overvoltage / undervoltage protector B, and overvoltage / undervoltage protector C, respectively, and then connected in parallel to the power grid. Overvoltage / undervoltage protector A has a switch K1, overvoltage / undervoltage protector B has a switch K2, and overvoltage / undervoltage protector C has a switch K3. Switch K1 controls the on / off state of the photovoltaic inverter PCS under grid voltage, switch K2 controls the on / off state of the load under grid voltage, and switch K3 controls the on / off state of the AC contactor under grid voltage. The photovoltaic inverter PCS has four ports: a grid port, a backup power port, a PV port, and a battery port. The grid port is used to connect to the mains power for normal power supply. The backup power port provides power to prevent load power outages when the grid voltage exceeds the permissible range. The PV port receives solar energy collected by the photovoltaic panels, and the battery port stores the electrical energy converted by the inverter from the photovoltaic panels, so that it can be supplied with power through the backup power port. If the grid cannot supply power to the load, for example, if the grid voltage is not within the range of 150V-270V, switches K1 in over / under voltage protector A, K2 in over / under voltage protector B, and K3 in over / under voltage protector C will all disconnect. Simultaneously, the AC contactor connects the PCS and the load via a relay, and the photovoltaic inverter PCS provides power to the load in the photovoltaic energy storage system through the backup power port. However, the photovoltaic energy storage system described above has a complex topology, a high failure rate, and poor reliability.

[0050] To address the aforementioned technical problems, this application provides an over / under voltage protector for photovoltaic energy storage systems. Please refer to [link / reference]. Figure 4 , Figure 5 as well as Figure 6 , Figure 4 A circuit diagram of an energy storage system with over / under voltage protection provided in the embodiments of this application; Figure 5 Another circuit diagram of the energy storage system provided in this application embodiment, which includes an over / under voltage protector; Figure 6 Another circuit diagram of the energy storage system provided in the embodiments of this application, which includes an over / under voltage protector.

[0051] like Figure 4 , Figure 5 as well as Figure 6 As shown, the photovoltaic energy storage system includes the power grid, over / under voltage protector D, photovoltaic inverter PCS, load, photovoltaic panels, and batteries. The power supplied by the power grid can be single-phase AC, and the circuit topology of the photovoltaic energy storage system is shown below. Figure 5 As shown, the power supplied by the grid can be three-phase AC. The circuit topology of the photovoltaic energy storage system in this case is as follows: Figure 6 As shown.

[0052] In this embodiment, the over / under voltage protector D consists of an over / under voltage protector body, switch K1, and switch K2. Switches K1 and K2 are integrated into the over / under voltage protector body. Simultaneously, the AC contactor in the photovoltaic energy storage system can also be directly integrated into the over / under voltage protector body (not shown in the figure), thus eliminating the need to connect the AC contactor and the load in parallel to the grid. This significantly reduces the number of components in the photovoltaic energy storage system, saving costs and improving the stability of the system. Switches K1 and K2 each include a first terminal, a second terminal, and a third terminal. The photovoltaic inverter PCS includes three ports: an off-grid port, a PV port, and a battery port. The off-grid port can be integrated from the backup power supply port and the grid port, thereby saving wiring harnesses and reducing system redundancy and failure rate.

[0053] Specifically, when the power supply from the grid is single-phase AC, the first terminals of switches K1 and K2 are electrically connected to the live wire L and neutral wire N in the grid, respectively. When the power supply from the grid is three-phase AC, the first terminals of switches K1 and K2 are electrically connected to the live wires L1, L2, L3, and neutral wire N in the grid, respectively. The second terminal of switch K1 is electrically connected to the grid-connected / off-grid port of the photovoltaic inverter PCS, and the second terminal of switch K2 is connected to the load. The third terminals of switches K1 and K2 are connected in series, thereby enabling switch K1 to control the on / off switching of the photovoltaic inverter PCS with the grid voltage, and switch K2 to control the on / off switching of the load with the grid voltage. Additionally, the photovoltaic panel is electrically connected to the photovoltaic inverter through the PV port, and the battery is electrically connected to the photovoltaic inverter through the battery port.

[0054] exist Figure 4 and Figure 5 In the illustrated embodiment, when the mains power grid supplying the photovoltaic energy storage system is in an undervoltage or overvoltage state, the first and second terminals of switches K1 and K2 on the overvoltage and undervoltage protectors are disconnected, thereby disconnecting the mains power grid from the photovoltaic inverter PCS and the load. At the same time, the second and third terminals of switches K1 and K2 on the overvoltage and undervoltage protectors are connected, thereby enabling the batteries in the photovoltaic energy storage system to supply power to the load, ensuring uninterrupted power supply to the load when the mains power grid is in an undervoltage or overvoltage state.

[0055] In some embodiments, this application also provides an energy storage system, comprising:

[0056] Power grid;

[0057] Several energy storage modules and loads;

[0058] An over / under voltage protector includes an over / under voltage protector body and at least two switches, each of which is integrated on the over / under voltage protector body.

[0059] In this configuration, the energy storage module and the load are both connected in parallel to the power grid, and at least one energy storage module and at least one load are connected in series with a switch and then connected in parallel to the power grid.

[0060] When the power grid is in an undervoltage or overvoltage state, the energy storage module, the load and the power grid are simultaneously disconnected through their respective corresponding switches, and the energy storage module and the load are connected through their respective corresponding switches, so that the energy storage module can supply power to the load.

[0061] Specifically, in an energy storage system, at least one load among multiple loads can supply power to the other loads; this load can be an energy storage module. When the energy storage module is a photovoltaic energy storage module, it can consist of a photovoltaic inverter (PCS), photovoltaic panels, and batteries. When the power grid is in an undervoltage or overvoltage state, each load is simultaneously disconnected from the power grid via its corresponding switch, while the energy storage module is connected to other non-energy storage module loads via its corresponding switch, thereby enabling the energy storage module to supply power to the other non-energy storage module loads.

[0062] In some embodiments, such as Figure 7 As shown, the energy storage system is a photovoltaic energy storage system, and the power supplied by the grid is single-phase AC. The switches integrated on the over / under voltage protector body include a first bidirectional thyristor switch VS1 and a second bidirectional thyristor switch VS2. A controller is provided on the over / under voltage protector body. The gate G and main electrode T2 of the first bidirectional thyristor switch VS1 are electrically connected to the grid through the controller, and the main electrode T1 is electrically connected to the load. The gate G of the second bidirectional thyristor switch VS2 is electrically connected to the grid, the main electrode T1 is electrically connected to the grid and connected to the photovoltaic energy storage module through the load, and the main electrode T2 is electrically connected to the photovoltaic energy storage module.

[0063] Specifically, when the grid voltage is normal, the main electrode T1 of the first bidirectional thyristor switch VS1 is the anode, and the main electrode T2 of the first bidirectional thyristor switch VS1 is the cathode, meaning that the first bidirectional thyristor switch VS1 is in the on state; the main electrode T1 of the second bidirectional thyristor switch VS2 is the cathode, and the main electrode T2 of the second bidirectional thyristor switch VS2 is the anode, meaning that the second bidirectional thyristor switch VS2 is in the off state. When the grid voltage is undervoltage or overvoltage, the main electrode T1 of the first bidirectional thyristor switch VS1 is the cathode, and the main electrode T2 of the first bidirectional thyristor switch VS1 is the anode, meaning that the first bidirectional thyristor switch VS1 is in the off state; the main electrode T1 of the second bidirectional thyristor switch VS2 is the anode, and the main electrode T2 of the second bidirectional thyristor switch VS2 is the cathode, meaning that the second bidirectional thyristor switch VS2 is in the on state.

[0064] In some embodiments, such as Figure 7 As shown, the power supply terminal provided by the power grid to the load is equipped with a rectifier filter E. Specifically, by setting the rectifier filter E at the power supply terminal provided by the power grid to the load, the AC power at the power supply terminal can be converted into DC power, thereby enabling power supply to the load in the photovoltaic energy storage system.

[0065] exist Figure 7 In the specific embodiment shown, the rectifier filter E includes diode VD1, diode VD2, capacitor C1, and capacitor C2; wherein, the positive terminal of diode VD1 is connected to the N terminal of the AC power supply, the negative terminal is connected to the positive terminal of diode VD2 and connected to the L terminal of the AC power supply through capacitor C1; one end of capacitor C2 is connected to the negative terminal of diode VD2, and the other end is connected to the N terminal of the AC power supply and the positive terminal of diode VD1 respectively.

[0066] The over / under voltage protector and energy storage system provided in this application embodiment consist of an over / under voltage protector body and at least two switches. Each switch is integrated into the over / under voltage protector body. Simultaneously, at least two loads corresponding to the number of switches are connected in parallel to the power grid. Each load has one of the aforementioned switches connected to the power grid. Therefore, when the power grid is in an undervoltage or overvoltage state, each load can be simultaneously disconnected from the power grid via its corresponding switch. This application eliminates the need for a separate over / under voltage protector connected in series with each load, thus enabling the switching of various loads on the power grid. This reduces the bulk of the power grid, decreases the number of wiring harnesses in the lines, saves costs, and improves the stability of the power grid.

[0067] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An over / under voltage protector, characterized in that, include: Over / under voltage protector body; At least two switches, each of which is integrated on the over / under voltage protector body; In this configuration, at least two loads are connected in parallel to the power grid after being connected in series with a switch; when the power grid is in an undervoltage or overvoltage state, each load is simultaneously disconnected from the power grid through its corresponding switch. At least one of the loads serves as an energy storage module. When the power grid is in an undervoltage or overvoltage state, each load is simultaneously disconnected from the power grid through its corresponding switch. The energy storage module is connected to other loads that are not energy storage modules through their corresponding switches, so that the energy storage module can supply power to the loads that are not energy storage modules. The switches integrated on the over / under voltage protector body include a first bidirectional thyristor switch and a second bidirectional thyristor switch, and a controller is provided on the over / under voltage protector body; In this configuration, the gate G and main electrode T2 of the first bidirectional thyristor switch are both electrically connected to the power grid through the controller, and the main electrode T1 is electrically connected to the load that is not an energy storage module; the gate G of the second bidirectional thyristor switch is electrically connected to the power grid, the main electrode T1 is electrically connected to the power grid and is electrically connected to the energy storage module through the load that is not an energy storage module, and the main electrode T2 is electrically connected to the energy storage module. When the grid voltage is normal, the first bidirectional thyristor switch is in the ON state and the second bidirectional thyristor switch is in the OFF state; when the grid voltage is undervoltage or overvoltage, the first bidirectional thyristor switch is in the OFF state and the second bidirectional thyristor switch is in the ON state.

2. The over / under voltage protector according to claim 1, characterized in that, The energy storage module is a photovoltaic energy storage module.

3. The over / under voltage protector according to claim 2, characterized in that, The photovoltaic energy storage module includes a photovoltaic inverter, a photovoltaic panel, and a battery; The photovoltaic inverter includes an off-grid port, a PV port, and a battery port. The off-grid port is electrically connected to the switch. The photovoltaic panel is electrically connected to the photovoltaic inverter through the PV port, and the battery is electrically connected to the photovoltaic inverter through the battery port.

4. The over / under voltage protector according to claim 1, characterized in that, The power supply provided by the power grid to the load is single-phase AC or three-phase AC.

5. The over / under voltage protector according to claim 4, characterized in that, The power supply terminal of the power grid to the load is equipped with a rectifier filter.

6. The over / under voltage protector according to claim 5, characterized in that, The rectifier filter includes diode VD1, diode VD2, capacitor C1, and capacitor C2; In this configuration, the positive terminal of diode VD1 is connected to the N terminal of the AC power supply, and the negative terminal is connected to the positive terminal of diode VD2 and connected to the L terminal of the AC power supply through capacitor C1; one end of capacitor C2 is connected to the negative terminal of diode VD2, and the other end is connected to the N terminal of the AC power supply and the positive terminal of diode VD1.

7. An energy storage system, characterized in that, include: Power grid; Several energy storage modules and loads; An over / under voltage protector includes an over / under voltage protector body and at least two switches, each of which is integrated on the over / under voltage protector body. The energy storage module and the load are both connected in parallel to the power grid, and at least one of the energy storage modules and at least one of the loads are connected in series with a switch and then connected in parallel to 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 simultaneously disconnected through their respective corresponding switches, and the energy storage module and the load are connected through their respective corresponding switches, so that the energy storage module can supply power to the load; The switches integrated on the over / under voltage protector body include a first bidirectional thyristor switch and a second bidirectional thyristor switch, and a controller is provided on the over / under voltage protector body; In this configuration, the gate G and main electrode T2 of the first bidirectional thyristor switch are both electrically connected to the power grid through the controller, and the main electrode T1 is electrically connected to the load that is not an energy storage module; the gate G of the second bidirectional thyristor switch is electrically connected to the power grid, the main electrode T1 is electrically connected to the power grid and is electrically connected to the energy storage module through the load that is not an energy storage module, and the main electrode T2 is electrically connected to the energy storage module. When the grid voltage is normal, the first bidirectional thyristor switch is in the ON state and the second bidirectional thyristor switch is in the OFF state; when the grid voltage is undervoltage or overvoltage, the first bidirectional thyristor switch is in the OFF state and the second bidirectional thyristor switch is in the ON state.

8. The energy storage system according to claim 7, characterized in that, The energy storage module is a photovoltaic energy storage module.

Images