Energy storage inverter system and energy storage system

Abstract

The utility model relates to an energy storage inverter system and an energy storage system. In the energy storage inverter system, a direct current input end of an off-grid and grid-connected inverter device is connected with a photovoltaic terminal, and a grid-connected alternating current output end of the off-grid and grid-connected inverter device is connected with a mains supply terminal; the direct current input and output end of the off-grid and grid-connected inverter device is connected with the battery terminal, and the off-grid alternating current output end of the off-grid and grid-connected inverter device is connected with the off-grid terminal; the input end of the bypass switch is connected with the grid-connected alternating current output end of the off-grid and grid-connected inverter, the output end of the bypass switch is connected with the off-grid alternating current output end of the off-grid and grid-connected inverter, and the controlled end of the bypass switch is connected with the control device; the first current metering device is arranged between the input end of the bypass switch and the mains supply terminal. According to the technical scheme of the utility model, the problem of the abnormal function of the energy storage inverter system caused by the easy installation error of the current sensor in the prior art can be solved, and the beneficial effects of simplifying the installation and improving the usability can be achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to an energy storage inverter system and an energy storage system. Background Art

[0002] The energy storage inverter system is a device that converts hybrid DC power (DC power from batteries + DC power from solar photovoltaic panels) into AC power. When there is mains power, the hybrid DC power can be converted into AC power and output to the grid and loads. When the grid is out of power, the energy storage inverter system will enter off-grid mode, converting the hybrid DC power into AC power and outputting it to the off-grid port to power household loads.

[0003] Figure 1 It is a structural diagram of the energy storage system of related technology, such as Figure 1 As shown, existing energy storage inverter systems require the installation of external current sensors (CTs) near the household entrance during wiring. These sensors monitor the direction and magnitude of the current in the incoming line, thereby calculating the amount of electricity purchased (or sold) at the household entrance. The energy storage inverter system's digital signal processor (DSP) controls the inverter's input and output power based on data detected by the external CTs, enabling the inverter system to achieve zero output to the grid, control input and output power, and maintain statistics on purchased and sold electricity.

[0004] Due to these functions of external CTs, installation must ensure that the CT clamping position (at the household entrance), the CT wire properties (hot and neutral), and the CT direction are correct. However, during actual installation, due to the complex on-site construction environment and the large number of connected wires, it is easy to clamp the CT wire in the wrong position (clamping it to the inverter mains output, excluding general loads), clamp the CT wire with the wrong properties (clamping it to the neutral wire), and even clamp the CT in the wrong direction (causing confusion between buying and selling electricity).

[0005] Currently, no effective solution has been proposed to the problem that current sensors in related technologies are prone to installation errors, which may lead to malfunction of energy storage inverter systems. Utility Model Content

[0006] The energy storage inverter system and energy storage system provided by the embodiments of the present invention at least solve the problem in the related art that the current sensor is easily installed incorrectly, which may cause abnormal function of the energy storage inverter system.

[0007] A storage energy inverter system comprises: an off-grid inverter device, a control device, a bypass switch and a first current metering device, as well as a mains connection terminal, an off-grid connection terminal, a photovoltaic connection terminal and a battery connection terminal; wherein the DC input terminal of the off-grid inverter device is connected to the photovoltaic connection terminal, and the grid-connected AC output terminal of the off-grid inverter device is connected to the mains connection terminal; the DC input and output terminals of the off-grid inverter device are connected to the battery connection terminal, and the off-grid AC output terminal of the off-grid inverter device is connected to the off-grid connection terminal; the input terminal of the bypass switch is connected to the grid-connected AC output terminal of the off-grid inverter device, the output terminal of the bypass switch is connected to the off-grid AC output terminal of the off-grid inverter device, and the controlled terminal of the bypass switch is connected to the control device; the first current metering device is arranged between the input terminal of the bypass switch and the mains connection terminal, and is used to provide the detected bidirectional current to the control device.

[0008] In some embodiments, the off-grid terminal is used to connect all loads to be powered, and the mains power is indirectly connected to all loads to be powered via the mains power terminal.

[0009] In some embodiments, the control device is used to turn on the bypass switch so that one or more of the off-grid inverter device and the mains power supply all the loads to be powered; the control device is also used to turn off the bypass switch so that the off-grid inverter device alone supplies power to all the loads to be powered.

[0010] In some embodiments, the control device is used to count the net amount of electricity flowing in and out between the energy storage inverter system and the mains according to the bidirectional current detected by the first current metering device.

[0011] In some embodiments, the first current metering device is an AC Hall current sensor or a bidirectional ammeter, and the bypass switch is a relay switch.

[0012] In some embodiments, the off-grid and grid-connected inverter device includes: an MPPT module, a DC / AC converter, a grid-connected relay and an off-grid relay, wherein the MPPT module is arranged between the photovoltaic terminal and the DC input terminal of the DC / AC converter; the grid-connected relay is arranged between the AC output terminal of the DC / AC converter and the mains terminal; and the off-grid relay is arranged between the AC output terminal of the DC / AC converter and the off-grid terminal.

[0013] In some embodiments, the energy storage inverter system further includes: a second current metering device, which is arranged between the output end of the bypass switch and the off-grid terminal, and is used to provide the detected current to the control device.

[0014] In some embodiments, multiple phase lines and a neutral line are connected between the input end of the bypass switch and the mains terminal, and there are multiple first current metering devices, each of which is respectively arranged on each phase line connected between the input end of the bypass switch and the mains terminal.

[0015] In some embodiments, multiple phase lines and a neutral line are connected between the output end of the bypass switch and the off-grid terminal, and there are multiple second current metering devices, each of which is respectively arranged on each phase line connected between the output end of the bypass switch and the off-grid terminal.

[0016] An energy storage system includes the above-mentioned energy storage inverter system, as well as solar photovoltaic panels, batteries and a distribution board, wherein the distribution board includes a main circuit breaker, a load circuit breaker and a load connector; wherein the solar photovoltaic panels are connected to the photovoltaic terminals; the batteries are connected to the battery terminals; the input of the main circuit breaker is connected to the mains power, and the output of the main circuit breaker is connected to the mains power terminal; the input of the load circuit breaker is connected to the off-grid terminal, and the output of the load circuit breaker is connected to the load connector, and the load connector is used to connect all loads to be powered.

[0017] The energy storage inverter system and energy storage system provided by the embodiments of the present invention adopt a method in which the DC input end of the off-grid-connected inverter device is connected to the photovoltaic terminal, and the AC output end of the off-grid-connected inverter device is connected to the mains terminal; the DC input and output ends of the off-grid-connected inverter device are connected to the battery terminal, and the AC output end of the off-grid-connected inverter device is connected to the off-grid terminal; the input end of the bypass switch is connected to the AC output end of the off-grid-connected inverter device, the output end of the bypass switch is connected to the AC output end of the off-grid-connected inverter device, and the controlled end of the bypass switch is connected to the control device; the first current metering device is arranged between the input end of the bypass switch and the mains terminal, which solves the problem of abnormal function of the energy storage inverter system caused by the easy installation error of the current sensor in the related art, and achieves the beneficial effect of simplifying installation and improving ease of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without inventive efforts.

[0019] Figure 1 It is a structural diagram of an energy storage system in related technology.

[0020] Figure 2 4 is a structural block diagram of the energy storage inverter system of this embodiment.

[0021] Figure 3 This is a preferred structural block diagram of the energy storage inverter system of this embodiment.

[0022] Figure 4 4 is a structural block diagram of the energy storage system of this embodiment.

[0023] Figure 5 Schematic diagram of the structure of the energy storage system of this embodiment.

[0024] Figure 6 3 is a circuit topology diagram of the energy storage inverter system of this embodiment. DETAILED DESCRIPTION

[0025] The following describes embodiments of the present invention in more detail with reference to the accompanying drawings. Although the drawings illustrate certain embodiments of the present invention, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0026] This embodiment provides an energy storage inverter system. Figure 2 This is a structural block diagram of the energy storage inverter system of this embodiment, as shown in Figure 2 As shown, the energy storage inverter system includes: an off-grid and grid-connected inverter device 1, a control device 2, a bypass switch 3 and a first current metering device 4, as well as a mains connection terminal 5, an off-grid connection terminal 6, a photovoltaic connection terminal 7 and a battery connection terminal 8.

[0027] The DC input terminal of the off-grid-connected inverter device 1 is connected to the photovoltaic terminal 7, and the grid-connected AC output terminal of the off-grid-connected inverter device 1 is connected to the mains terminal 5; the DC input and output terminals of the off-grid-connected inverter device 1 are connected to the battery terminal 8, and the off-grid AC output terminal of the off-grid-connected inverter device 1 is connected to the off-grid terminal 6; the input terminal of the bypass switch 3 is connected to the grid-connected AC output terminal of the off-grid-connected inverter device 1, the output terminal of the bypass switch 3 is connected to the off-grid AC output terminal of the off-grid-connected inverter device 1, and the controlled terminal of the bypass switch 3 is connected to the control device 2; the first current metering device 4 is arranged between the input terminal of the bypass switch 3 and the mains terminal 5, and is used to provide the detected bidirectional current to the control device 2.

[0028] The off-grid inverter device of this embodiment may include a grid-connected inverter portion and an off-grid inverter portion. The grid-connected inverter portion, also known as the mains-side (grid-connected) circuit, primarily includes a grid-connected inverter. Furthermore, it may include: a DC / DC converter for adjusting the voltage output by the solar photovoltaic panel so that the voltage output by the solar photovoltaic panel matches the requirements of the grid-connected inverter; a maximum power point tracking (MPPT) module for ensuring maximum energy output from the solar photovoltaic panel by adjusting current and voltage; and a monitoring and communication module and anti-islanding protection device related to interaction with the mains. The grid-connected inverter includes a DC / AC converter, a phase-locked loop, and a filter. The off-grid inverter portion, also known as the off-grid circuit, primarily includes an off-grid inverter. In addition, it can also include a maximum power point tracking (MPPT) module for ensuring maximum energy output from the solar photovoltaic panel by adjusting current and voltage; a battery management system (BMS) for monitoring battery status and controlling the battery's charge and discharge process; a DC / DC converter for adjusting the battery output voltage to match the DC load; a charge controller for managing the charging process from the solar photovoltaic panel to the battery; and a monitoring and communication module for detecting system status. An off-grid inverter includes a DC / AC converter, a filter, and a load management module for automatically adjusting output based on battery status and load demand.

[0029] The off-grid and grid-connected inverter device of this embodiment may also be an integrated off-grid and grid-connected inverter device, where the off-grid inverter part and the grid-connected inverter part share one AC / DC converter. Figure 3 This is a preferred structural block diagram of the energy storage inverter system of this embodiment, as shown in FIG. Figure 3As shown, the off-grid and grid-connected inverter device 1 includes: an MPPT module 10, a DC / AC converter 11, a grid-connected relay 12 and an off-grid relay 13, wherein the MPPT module 10 is arranged between the photovoltaic terminal 7 and the DC input terminal of the DC / AC converter 11; the grid-connected relay 12 is arranged between the AC output terminal of the DC / AC converter 11 and the mains terminal 5; and the off-grid relay 13 is arranged between the AC output terminal of the DC / AC converter 11 and the off-grid terminal 6.

[0030] When the off-grid relay 13 is closed and the grid-connected relay 12 and the bypass switch 3 are disconnected, the energy storage inverter system enters the off-grid state, and the load is powered by the energy storage inverter; when the grid-connected relay 12 and the bypass switch 3 are closed and the off-grid relay 13 is closed, the energy storage inverter system enters the grid-connected state, and the load is powered by the energy storage inverter and / or the mains.

[0031] Figure 2 In the system shown, the first current metering device 4 is disposed between the input of the bypass switch 3 and the mains terminal 5. This means that the current metering device is already built into the energy storage inverter system when it is delivered from the factory. During actual construction, there is no need to install an additional current metering device at the household entrance. Instead, the installation can be completed by simply connecting the corresponding lines according to the terminals provided on the energy storage inverter system cabinet. This ensures that the current metering device's related functions, such as zero output to the grid, input and output power control, and statistics on purchased and sold electricity, function properly.

[0032] In the above energy storage inverter system, the off-grid terminal is used to connect all the loads to be powered, and the mains power is indirectly connected to all the loads to be powered via the mains power terminal. Figure 1 In the energy storage system shown, since the power of the energy storage inverter system in the related art is relatively small and insufficient to supply power to all the loads to be powered, the loads to be powered are usually divided into general loads and important loads. Before the mains power is connected to the mains terminal of the energy storage inverter system, a portion of the power is separated to supply power to the general loads. When the power grid is normal, the mains power supplies power to the general loads through the general load circuit breaker directly connected to the main circuit breaker, and the important loads are supplied by the power output of the energy storage inverter system and the mains current through the bypass relay circuit. Therefore, the current supplied by the mains power to the general loads does not pass through the energy storage inverter system, and when the power grid is abnormal, the important loads connected to the off-grid terminal can only be powered by the energy storage inverter system. Figure 1 The energy storage inverter system of the related art shown has complex wiring and the current metering device must be installed on the mains power supply side. Figure 1 The application scenario of the energy storage inverter system shown is different in that Figure 2In the energy storage inverter system shown, all mains power is routed through the mains terminals. Loads are no longer divided into general loads and critical loads. Instead, all loads are powered by the power output of the energy storage inverter system and the mains current via the bypass relay circuit. This simplifies the wiring and number of components in the distribution board (for example, reducing the number of circuit breakers). It also allows the current metering device to be built into the energy storage inverter system, eliminating the need for a line to connect to the mains power inlet.

[0033] This embodiment also provides an energy storage system, Figure 4 is a structural block diagram of the energy storage system of this embodiment, Figure 5 This is a schematic diagram of the structure of the energy storage system of this embodiment. Figure 4 As shown, the energy storage system includes Figure 2 or Figure 3 The energy storage inverter system 100 shown, as well as the solar photovoltaic panel 200, the battery 300 and the distribution board 400, the distribution board 400 includes a main circuit breaker 410, a load circuit breaker 420 and a load connector 430; wherein the solar photovoltaic panel 200 is connected to the photovoltaic terminal 7; the battery 300 is connected to the battery terminal 8; the input end of the main circuit breaker 410 is connected to the mains power, and the output end of the main circuit breaker 410 is connected to the mains power terminal 5; the input end of the load circuit breaker 420 is connected to the off-grid terminal 6, and the output end of the load circuit breaker 420 is connected to the load connector 430, and the load connector 430 is used to connect all the loads to be powered 500.

[0034] When the grid is normal, the control device 2 of the energy storage inverter system turns on the bypass switch 3, allowing the off-grid inverter 1 and one or more of the mains to power all the loads to be powered. When the grid is abnormal, the control device 2 turns off the bypass switch 3, allowing the off-grid inverter 1 to power all the loads to be powered alone.

[0035] The control device 2 can also count the net amount of electricity flowing in and out between the energy storage inverter system and the mains according to the bidirectional current detected by the first current metering device 4 .

[0036] The control device 2 mentioned above may be a digital signal processor (DSP).

[0037] In some embodiments, the first current metering device 4 may be, but is not limited to, an AC Hall effect current sensor or a bidirectional ammeter. Both these devices can detect the magnitude and direction of current to measure the amount of power delivered from the energy storage inverter system to the grid and the amount of power delivered from the grid to the energy storage inverter system, thereby determining the amount of power sold and purchased. Based on this first current metering device 4, the control device 2 can limit power purchases and sales, limit zero grid output, and detect household power purchases and sales, effectively acting as an electric meter.

[0038] In some embodiments, the bypass switch 3 is a relay switch, or a bypass relay. The rated current of the selected bypass relay is not less than the sum of the maximum output AC current of the energy storage inverter system and the maximum output AC current allowed by the mains.

[0039] To calculate the actual power consumption of household loads, in some embodiments, the energy storage inverter system may further include a second current metering device, disposed between the output terminal of the bypass switch 3 and the off-grid terminal 6, configured to provide a detected current to the control device 2. The control device 2 calculates the power consumption of all loads to be powered based on the current detected by the second current metering device. The second current metering device may be an AC Hall current sensor or a unidirectional ammeter.

[0040] Figure 6 This is a circuit topology diagram of the energy storage inverter system of this embodiment, as shown in FIG. Figure 6 As shown, in some embodiments, multiple phase lines (for example Figure 6 U, W in the figure) and a neutral line N, there are multiple first current metering devices 4, and each first current metering device 4 is respectively provided on each phase line connected between the input end of the bypass switch 3 and the mains terminal.

[0041] In other embodiments, multiple phase lines (eg Figure 6 L1, L2 in the bypass switch 3) and a neutral line N, there are multiple second current metering devices, each of which is respectively arranged on each phase line connected between the output end of the bypass switch 3 and the off-grid terminal.

[0042] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "a plurality of" mentioned in the embodiments of the present invention are illustrative and not restrictive. Those skilled in the art should understand that unless the context clearly indicates otherwise, they should be understood as "one or more".

[0043] The term "embodiment" in this specification refers to the specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments are referenced to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0044] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection. It should be noted that a person of ordinary skill in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An energy storage inverter system, characterized in that include: An off-grid inverter device, a control device, a bypass switch and a first current metering device, as well as a mains connection terminal, an off-grid connection terminal, a photovoltaic connection terminal and a battery connection terminal; wherein, The DC input terminal of the off-grid and on-grid inverter device is connected to the photovoltaic terminal, and the grid-connected AC output terminal of the off-grid and on-grid inverter device is connected to the mains terminal; The DC input and output terminals of the off-grid and grid-connected inverter device are connected to the battery terminals, and the off-grid AC output terminals of the off-grid and grid-connected inverter device are connected to the off-grid terminals; The input end of the bypass switch is connected to the grid-connected AC output end of the off-grid-connected inverter device, the output end of the bypass switch is connected to the off-grid AC output end of the off-grid-connected inverter device, and the controlled end of the bypass switch is connected to the control device; The first current metering device is arranged between the input end of the bypass switch and the mains connection terminal, and is used to provide the detected bidirectional current to the control device.

2. The energy storage inverter system according to claim 1, characterized in that: The off-grid terminal is used to connect all loads to be powered, and the mains power is indirectly connected to all loads to be powered via the mains power terminal.

3. The energy storage inverter system according to claim 2, characterized in that: The control device is used to turn on the bypass switch so that one or more of the off-grid and on-grid inverter device and the mains power supplies power to all the loads to be powered; the control device is also used to turn off the bypass switch so that the off-grid and on-grid inverter device alone supplies power to all the loads to be powered.

4. The energy storage inverter system according to claim 2, characterized in that: The control device is used to count the net amount of electricity flowing in and out between the energy storage inverter system and the mains according to the bidirectional current detected by the first current metering device.

5. The energy storage inverter system according to claim 1, characterized in that: The first current metering device is an AC Hall current sensor or a bidirectional ammeter, and the bypass switch is a relay switch.

6. The energy storage inverter system according to claim 1, characterized in that: The off-grid and on-grid inverter device includes: an MPPT module, a DC / AC converter, a grid-connected relay and an off-grid relay, wherein: The MPPT module is arranged between the photovoltaic terminal and the DC input terminal of the DC / AC converter; the grid-connected relay is arranged between the AC output terminal of the DC / AC converter and the mains terminal; and the off-grid relay is arranged between the AC output terminal of the DC / AC converter and the off-grid terminal.

7. The energy storage inverter system according to claim 1, characterized in that: The energy storage inverter system further includes: a second current metering device, which is arranged between the output end of the bypass switch and the off-grid connection terminal and is used to provide the detected current to the control device.

8. The energy storage inverter system according to claim 1, characterized in that: Multiple phase lines and a neutral line are connected between the input end of the bypass switch and the mains connection terminal. There are multiple first current metering devices, and each first current metering device is respectively arranged on each phase line connected between the input end of the bypass switch and the mains connection terminal.

9. The energy storage inverter system according to claim 7, characterized in that: Multiple phase lines and a neutral line are connected between the output end of the bypass switch and the off-grid terminal. There are multiple second current metering devices, and each second current metering device is respectively arranged on each phase line connected between the output end of the bypass switch and the off-grid terminal.

10. An energy storage system, characterized in that The energy storage inverter system comprises the energy storage inverter system according to any one of claims 1 to 9, as well as a solar photovoltaic panel, a battery and a distribution board, wherein the distribution board comprises a main circuit breaker, a load circuit breaker and a load connector; wherein, The solar photovoltaic panel is connected to the photovoltaic terminal; The battery is connected to the battery terminal; The input end of the main circuit breaker is connected to the mains power, and the output end of the main circuit breaker is connected to the mains power terminal; The input end of the load circuit breaker is connected to the off-grid connection terminal, and the output end of the load circuit breaker is connected to the load connector. The load connector is used to connect all loads to be powered.

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