Parallel operation connection device and parallel operation facility

Abstract

This application discloses a parallel operation connection device and parallel operation equipment. The parallel operation connection device includes a control switch, a hub, a first connector, and a second connector. The hub is connected between an AC power supply and the first connector and the second connector to form two identical AC lines, both of which are controlled to be turned on and off by the control switch. The first connector is configured to be adaptively connectable to a first energy storage inverter, and the second connector is configured to be adaptively connectable to a second energy storage inverter. The connection of the control switch is configured such that when the first connector is connected to the first energy storage inverter and the second connector is connected to the second energy storage inverter, the control switch turns on to simultaneously conduct the two AC lines; when the connection between the first connector and the first energy storage inverter is disconnected and / or the connection between the second connector and the second energy storage inverter is disconnected, the control switch turns off to simultaneously disconnect the two AC lines.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the priority of a Chinese patent application with an application number of 202310528762.8 and an invention title of "Parallel Operation Connection Device and Parallel Operation Equipment", which was filed with the China National Intellectual Property Administration on May 11, 2023, and all of its contents are incorporated herein by reference.

[0002] This application relates to the technical field of new energy. Specifically, it relates to the related technology of parallel operation of energy storage inverters, and particularly to the commercial power input technology in the parallel operation of portable bidirectional energy storage inverters.

Background Art

[0003] With the increasing acceptance of portable energy storage inverters by people, the market's demand for the parallel operation of portable energy storage inverters is growing stronger. For portable energy storage inverters, it is also desired to achieve a highly reliable, fast, and convenient parallel operation function (realize that a large load is sometimes connected to the parallel operation output) and meet the requirement that it can be easily operated by ordinary people. Current portable energy storage inverters have already changed from the mode of conventional battery cell discharge off - grid inverters (as shown in Figure 1) to the current mainstream bidirectional inverter topology technology (as shown in Figure 2), and are also equipped with an emergency UPS (uninterruptible power supply) bypass function.

[0004] As shown in FIG. 1, a conventional battery cell discharge off-grid inverter is used to supply power to a load only through battery discharge. During AC (alternating current) charging, it is necessary to charge the storage battery through a charging adapter. The structure of such a topology and its control method are both relatively simple. However, charging by an adapter generally has a small current, requires an external charger, and has a higher cost than a bidirectional inverter topology. Also, it lacks the function of automatically switching to battery inversion to supply power to the load when commercial power is cut off, that is, the UPS function (backup function) of automatically switching to commercial power to supply power to the load when power is input. Since it is a cell discharge off-grid inverter, there is no problem with commercial power input in parallel operation, and it is relatively easy to achieve output expansion by parallel operation of the inverter. However, such a topology no longer has technological superiority in the current portable energy storage market. Even if parallel operation is achieved, it has drawbacks such as slow charging and the inability to supply power to the load in a charged state when the battery runs out, so it has been phased out in new products.

[0005] FIG. 2 shows the mainstream applicable topology of current portable energy storage inverters or commercial energy storage facilities. Such a topology has advantages such as enabling rapid charging of the battery, having a simple circuit, and having a UPS bypass function. Portable energy storage facilities are excellent in convenience, such as being easy to operate, lightweight, and easy to carry. It has already become an ordinary household electronic product and can be operated by ordinary people, so there are even higher requirements for reliability. Although the technology for single-unit use is already relatively mature, the parallel operation function still faces many challenges, such as the issue of how to ensure the same frequency, the same phase, and the same time of power-on / power-off of commercial power input in two energy storage inverters. If the frequencies or phases of commercial power input in the parallel operation of two energy storage inverters are different, or if power-on / power-off cannot be achieved simultaneously, either case will bring safety risks and reduce the reliability of parallel operation.

Summary of the Invention

[0006] Therefore, the present application proposes a parallel operation connection device, a bidirectional energy storage inverter, and related parallel operation equipment to solve the problems faced in the parallel operation of the above-mentioned conventional portable energy storage inverters and to realize the functions of the same frequency, the same phase, and the power-on / power-off at the same time of commercial power input in the parallel operation of the portable bidirectional energy storage inverter.

[0007] According to one aspect of the present application, a parallel operation connection device is proposed, which includes a control switch, a hub, a first connector, and a second connector. The hub is connected between an AC power supply and the first connector and the second connector to form two identical AC lines, both of which are controlled to be turned on and off by the control switch. The first connector is configured to be adaptively connectable to a first energy storage inverter, and the second connector is configured to be adaptively connectable to a second energy storage inverter. The connection of the control switch is such that when the first connector is connected to the first energy storage inverter and the second connector is connected to the second energy storage inverter, the control switch is turned on to simultaneously conduct the two AC lines, and when the connection between the first connector and the first energy storage inverter is disconnected and / or the connection between the second connector and the second energy storage inverter is disconnected, the control switch is turned off to simultaneously disconnect the two AC lines.

[0008] Furthermore, the hub incorporates a current collector line, to which a switch portion of the control switch for controlling the on / off of the current collector line is connected. A first end of the current collector line is connected to an AC power supply, and a second end of the current collector line is connected to an electrical connection line of the first connector to form a first AC line. The second end of the current collector line is further connected to an electrical connection line of the second connector to form a second AC line. The first AC line and the second AC line are the two identical AC lines.

[0009] Furthermore, the electrical connection lines of the first connector and the second connector are both three in number, corresponding to the live wire, the neutral wire, and the earth wire respectively.

[0010] Furthermore, both the first connector and the second connector have signal lines respectively connected to both ends of the control part of the control switch. When the first connector is connected to the first energy storage inverter and the second connector is connected to the second energy storage inverter, both ends of the control part of the control switch form a control loop through the signal line of the first connector, the internal circuit of the first energy storage inverter, the internal circuit of the second energy storage inverter, and the signal line of the second connector, and control is performed to turn on the control switch.

[0011] Furthermore, if there is a connector among the first connector and the second connector that is not connected to the energy storage inverter, both ends of the control part of the control switch do not form a control loop through the signal line of the first connector, the internal circuit of the first bi-directional energy storage inverter, the internal circuit of the second energy storage inverter, and the signal line of the second connector, the control part of the control switch loses power, and the switch part of the control switch is turned off.

[0012] Furthermore, both the first connector and the second connector have a first signal line, a second signal line, and a third signal line. One end of the control unit of the control switch is connected to the first signal line of the first connector, and the other end is connected to the third signal line of the second connector. The second signal line of the first connector is connected to the second signal line of the second connector. When connecting the connector to the energy storage inverter, the first signal line, the second signal line, and the third signal line are respectively connected corresponding to the first interface, the second interface, and the third interface of the energy storage inverter. Among them, the first interface and the second interface of the energy storage inverter are respectively the power supply terminal and the ground terminal of the energy storage inverter, and the second interface of the energy storage inverter is connected to the third interface.

[0013] Furthermore, both the first connector and the second connector further have a fourth signal line. Inside the connector, the fourth signal line is connected to the second signal line. When connecting the connector to the energy storage inverter, the fourth signal line is connected to the fourth interface of the energy storage inverter to provide an identification signal indicating that the connector is connected to the energy storage inverter.

[0014] Furthermore, the control switch is a relay. The control switch includes a contact group connected to the current collector line of the hub to control the on / off of the current collector line, and a control coil with one end connected to the first signal line of the first connector and the other end connected to the third signal line of the second connector.

[0015] Furthermore, the first connector is a plug fitted to the first energy storage inverter, and the second connector is a plug fitted to the second energy storage inverter.

[0016] Furthermore, the hub, the first connector, and the second connector are integrally formed and provided.

[0017] Furthermore, the parallel operation connection device further includes a plug for AC power connection, one end of which is insertable into an AC power outlet and the other end of which is connected to the hub.

[0018] According to another aspect of the present application, a parallel operation facility is further proposed, which includes the above-mentioned parallel operation connection device, a first energy storage inverter and a second energy storage inverter connected to the parallel operation connection device.

[0019] Furthermore, the first energy storage inverter is provided with a first detection circuit for detecting whether the first energy storage inverter is connected to one of the two same AC lines, and the second energy storage inverter is provided with a second detection circuit for detecting whether the second energy storage inverter is connected to the other of the two same AC lines.

[0020] The beneficial effects of this application are embodied as follows. In the parallel operation connection device proposed in this application, since the AC power lines connected by the first connector and the second connector are the same, in the case of parallel operation of energy storage inverters, it can be ensured that both the L / N lines are correctly connected, eliminating the need to consider the phase sequence problem. Moreover, the control switch turns on only when both the first connector and the second connector are connected to the energy storage inverters respectively. Thus, the AC power lines of the two energy storage inverters are simultaneously conducted to achieve the function of simultaneous power-on. Conversely, if the connection of one energy storage inverter is disconnected, the control switch turns off to simultaneously disconnect the AC power lines of the two energy storage inverters, realizing the function of simultaneous power-off. This can avoid the risk of damage to the other inverter due to abnormal power input in one inverter during parallel operation, and achieve the same power input for the two inverters in the case of parallel operation. Without considering the phase sequence problem of the input of the two inverters, if the first connector of this parallel operation connection device is fitted to one energy storage inverter and the second connector is fitted to the other energy storage inverter, AC inputs with the same frequency and the same phase can be realized for the two energy storage inverters. Moreover, since the control switch can turn on only when both of the two energy storage inverters are connected to the parallel operation connection device, parallel operation can be achieved by connecting the parallel operation connection device to the two energy storage inverters whether there is an AC power source or not.

[0021] In addition, the detection circuit in the energy storage inverter can detect whether the energy storage inverter is connected to the AC power line. When it is detected that the energy storage inverter is connected to the AC power line, it indicates that the parallel operation of the two inverters is possible. At this time, the signal output by the detection circuit is transmitted to the CPU, and the CPU can control the system to enter the parallel operation mode. There is no need to set the parallel operation function for each inverter via a panel. Therefore, this solution can reliably and conveniently handle the input in the parallel operation of the bidirectional inverter.

Brief Description of the Drawings

[0022] One or more embodiments will be exemplarily described with reference to the figures in the accompanying drawings corresponding thereto. These exemplary descriptions do not limit the embodiments. In the accompanying drawings, elements with the same reference numerals represent similar elements, and the figures in the accompanying drawings are not subject to scale limitations unless otherwise specified.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0023] Hereinafter, the present application will be further described with reference to the accompanying drawings, the embodiments for carrying out the invention, and examples. The examples are provided for illustrative purposes only and are not intended to be limiting in any way. It should be understood that terms such as "first", "second", "third", "fourth", etc. are used only to distinguish members (e.g., terminals, pins, etc.), and such terms should not be regarded as limitations on these members, nor do they themselves mean that these components have the aforementioned order, nor do they represent the arrangement order of one member relative to another member or the order in the manufacturing method.

Explanation of Reference Signs

[0024] PV1: Photoelectric power input source Grid: Commercial power BMS: Battery management system RLYA: Relay A RLYB: Relay B

[0025] Shown in FIG. 2 is the mainstream application topology of current portable energy storage inverters or commercial energy storage facilities. Such a topology has advantages such as being able to achieve rapid charging of the battery, having a simple circuit, and having a UPS bypass function. However, as an energy storage inverter with such a topology, in order to realize the parallel operation of two portable energy storage facilities with the function of a bidirectional inverter, it is necessary to solve the problems of the same frequency, the same phase, and the power-on / power-off at the same time of the commercial power input in the two inverters.

[0026] For example, in the problem of the same frequency of the commercial power input, it is required that the commercial power connected by the two bidirectional energy storage inverters is the same. One cannot be connected to a generator while the other is connected to commercial power, and it is particularly easy to make connection mistakes in double-phase live wire power transmission networks such as those in the United States and Japan.

[0027] For example, in the issue of in-phase commercial power input, it is required that two independent bidirectional energy storage inverters be correctly connected to the L / N lines. This is because when the energy storage inverter with a connection error switches to bypass, it will cause a short circuit at the output of the L / N lines. Specifically, as shown in Figure 2, for example, taking the AC connection terminals 1 and 2 of the energy storage inverter as an example, the correct connection form is that the AC connection terminal 1 of both energy storage inverters is connected to the live wire, and the AC connection terminal 2 of both is connected to the neutral wire, or the AC connection terminal 1 of both is connected to the neutral wire, and the AC connection terminal 2 of both is connected to the live wire. If the AC connection terminal 1 of one energy storage inverter is connected to the live wire and the AC connection terminal 2 is connected to the neutral wire, while the AC connection terminal 1 of the other energy storage inverter is connected to the neutral wire and the AC connection terminal 2 is connected to the live wire, it will cause an L / N output short circuit. Also, in the US specification outlets in the US market, the Japanese specification outlets in the Japanese market, and the European specification outlets in the European market, many outlets, such as two-hole outlets and four-hole outlets (double-sided insertable), do not have anti-misoperation measures, so it is difficult to guarantee in-phase. When the phases of two energy storage facilities are different, they need to undergo complex detection, report errors, and prohibit parallel operation. If the user is making a connection when there is no commercial power, it is even more difficult to determine whether the connection is correct. If the connection is incorrect at this time, when commercial power is input while the battery is feeding power to the load in the parallel operation of battery inversion, the power supply by the energy storage power supply will be interrupted, that is, it is necessary to repeatedly confirm whether the connection is correct, which causes great trouble to the user and at the same time requires checking each fault item by item according to the product manual.

[0028] When two energy storage inverters with commercial power input during parallel operation are not simultaneously powered off during an abnormal situation, there is a significant risk. This is because for the parallel operation of two independent energy storage inverters, the input lines are independent. After the two are in parallel operation and commercial power is input, both supply power to the load through the bypass, and the bypass outputs are separated. However, according to the UPS function, when the commercial power supply is cut off, it is required to convert to battery inversion to supply power to the load. So, during parallel operation, if the connection of one energy storage inverter is artificially disconnected or one energy storage inverter accidentally loosens and drops off, that energy storage inverter will convert to battery inversion to supply power by itself, while the output of the other remains commercial power. In this way, the commercial power and the inverted output at the output end are forced to be connected, causing a large current impact on the two inverters, with a large voltage difference between them and a risk of being forced to connect to the grid, which is likely to damage one of the inverters. Moreover, the risk of being forced to connect to the grid is prohibited by safety standards. Therefore, if these technical difficulties cannot be solved, the parallel operation of portable bidirectional energy storage inverters is difficult to popularize, and only a parallel operation function with various limiting conditions can be realized, and it also requires personnel with specialized knowledge to operate. This application proposes countermeasures for parallel operation only for these technical problems, achieving that it can be operated by ordinary people and realizing the parallel operation of a safe and reliable portable bidirectional energy storage inverter.

[0029] According to the embodiments of the present application, a parallel operation facility is proposed, which includes a parallel operation connection device and two energy storage inverters. When both of the two energy storage inverters are connected to the parallel operation connection device, an AC power supply (such as commercial power) with the same frequency and the same phase enters the two energy storage inverters simultaneously through the parallel operation connection device, realizing power-on at the same time. Moreover, when connecting the energy storage inverters and the parallel operation connection device, there is no need to consider the phase sequence problem. Conversely, if the connection between one energy storage inverter and the parallel operation connection device is disconnected, the connections between the two energy storage inverters and the AC power supply are disconnected simultaneously, realizing power-off at the same time. In addition, a detection circuit is provided inside the energy storage inverter to detect whether the energy storage inverter is connected to the AC line (such as the commercial power line). When the two energy storage inverters are both connected to the parallel operation connection device, it indicates that parallel operation of the two energy storage inverters is possible. When the signal detected by the detection circuit at this time is transmitted to the CPU, the CPU can control to enter the parallel operation mode. It should be understood that the "AC power supply" connected by the parallel operation connection device according to the present application may be a commercial power supply or other types of AC power supplies, and the present application is not limited thereto. Hereinafter, for the convenience of description, the present application will be described by taking the commercial power supply as an example.

[0030] The parallel operation connection device according to an embodiment of the present application includes a control switch, a hub, a first connector, and a second connector. The hub is connected between commercial power and the first connector and the second connector, and forms two identical commercial power lines including a first commercial power line reaching the first connector from commercial power through the hub and a second commercial power line reaching the second connector from commercial power through the hub. Both the first commercial power line and the second commercial power line are on-off controlled by the control switch. The first connector is configured to be adaptively connectable to a first energy storage inverter, and the second connector is configured to be adaptively connectable to a second energy storage inverter. The connection of the control switch is configured such that when the first connector is connected to the first energy storage inverter and the second connector is connected to the second energy storage inverter, the control switch is turned on to simultaneously conduct the first commercial power line and the second commercial power line, and when the connection between the first connector and the first energy storage inverter is disconnected and / or the connection between the second connector and the second energy storage inverter is disconnected, the control switch is turned off to simultaneously disconnect the first commercial power line and the second commercial power line. That is, if either the first connector or the second connector is not connected to the energy storage inverter, the control switch is in an off state, and the first commercial power line and the second commercial power line are simultaneously disconnected. In some embodiments, the energy storage inverter is a bidirectional energy storage inverter.

[0031] In some embodiments, the parallel operation connection device may further include a commercial power connection plug with one end insertable into a commercial power connection socket and the other end connected to the first end of the hub. The first connector and the second connector each have a plug adaptably fitted to an energy storage inverter, and both the first connector and the second connector have electrical connection lines and signal lines. The electrical connection lines of the first connector and the second connector are each three in number and respectively correspond to a live wire, a neutral wire, and an earth wire. The first end of the hub is connected to commercial power, and the electrical connection lines of the first connector are connected to the second end of the hub to form the first commercial power line, and the electrical connection lines of the second connector are connected to form the second commercial power line.

[0032] The control switch is a type of switch that can be controlled to turn on the switch when its control unit is energized, such as a relay, a circuit breaker, etc. The switch part of the control switch (for example, the contact of a relay) is connected to the current collector line in the hub and is used to control the on / off of the current collector line. The signal lines of the first connector and the second connector are respectively connected to both ends of the control unit of the control switch. Specifically, both ends of the control unit of the control switch (for example, the coil of a relay) are configured such that one end is connected to the first bidirectional energy storage inverter via the signal line of the first connector, and the other end is connected to the second bidirectional energy storage inverter via the signal line of the second connector. When the first connector is connected to the first bidirectional energy storage inverter and the second connector is connected to the second bidirectional energy storage inverter, both ends of the control unit of the control switch form a control loop through the signal line of the first connector, the internal circuit of the first energy storage inverter, the internal circuit of the second energy storage inverter, and the signal line of the second connector. In this control loop, the first energy storage inverter, the first connector, the control switch, the second connector, and the second energy storage inverter are connected in series. Only when both the first connector and the second connector are respectively connected to the energy storage inverters, the control loop is communicated, the control unit of the control switch is energized, the switch part of the control switch is turned on, and after the control switch is turned on, if commercial power is transmitted to the first connector and the second connector respectively through the current collector line, the two energy storage inverters can be connected to the commercial power line and powered on simultaneously. If there is a connector among the first connector and the second connector that is not connected to the energy storage inverter, both ends of the control unit of the control switch do not form a control loop through the signal line of the first connector, the internal circuit of the first energy storage inverter, the internal circuit of the second energy storage inverter, and the signal line of the second connector, the control unit of the control switch loses power, and the switch part of the control switch is turned off.That is, if one energy storage inverter is disconnected from the originally connected connector, the entire control loop will be in an off state, the control unit of the control switch will lose power, the control switch will turn off, and when the control switch turns off, the two energy storage inverters can be simultaneously disconnected from the commercial power line and powered off at the same time.

[0033] In some embodiments, both the first connector and the second connector have a first signal line, a second signal line, and a third signal line. One end of the control unit of the control switch is connected to the first signal line of the first connector, and the other end is connected to the third signal line of the second connector. The second signal line of the first connector is connected to the second signal line of the second connector. When connecting the connector to the energy storage inverter, the first signal line, the second signal line, and the third signal line are respectively connected corresponding to the first interface, the second interface, and the third interface of the energy storage inverter. Among them, the first interface and the second interface of the energy storage inverter are the power supply terminal and the ground terminal of the energy storage inverter respectively, and the second interface of the energy storage inverter is connected to the third interface. Further, both the first connector and the second connector further have a fourth signal line. Inside the connector (the first connector / the second connector), the fourth signal line is connected to the second signal line. When connecting the connector to the energy storage inverter, the fourth signal line is connected to the fourth interface of the energy storage inverter to provide an identification signal indicating that it is connected to the connector to the energy storage inverter. This identification signal can be received and detected by a detection circuit inside the energy storage inverter (details of the configuration and principle of the detection circuit will be described later).

[0034] In some embodiments, the control switch is a relay. The control switch includes a contact group connected to the current collector line of the hub to control the on / off of the current collector line, and a control coil with one end connected to the first signal line of the first connector and the other end connected to the third signal line of the second connector.

[0035] In some embodiments, the first connector is a plug fitted to the first energy storage inverter, and the second connector is a plug fitted to the second energy storage inverter. In some embodiments, the hub, the first connector, and the second connector of the parallel operation connection device may be integrally formed and provided, or may be separately formed and then assembled to form the parallel operation connection device.

[0036] Hereinafter, the present application will be described in more detail with specific examples. Referring to FIG. 3, the parallel operation connection device proposed in the embodiment of the present application includes four parts A, B, C, and D. Among them, A is a plug for commercial power connection (a plug equipped according to the markets of different countries) and can be connected to any commercial power outlet. B is a wire bundling location (hub), C is a plug fitted to the energy storage inverter provided on the first connector, and D is a plug fitted to the energy storage inverter provided on the second connector.

[0037] Specifically, one end of the plug A can be inserted into the commercial power outlet, and the G wire (ground wire), L wire (live wire), and N wire (neutral wire) at the other end are simultaneously inserted into the hub B. Inside the hub B, the L wire is incorporated with a control switch (such as a relay, circuit breaker, etc.) that controls to turn on the switch when energized. Although a relay is shown in Figure 3, it is not limited to this. In addition to the three electrical connection lines of L, G, and N (a is the G wire, b is the N wire, and c is the L wire) for the plugs C and D that are fitted to the energy storage inverter, there are four signal lines, and their connection method is that the first pin of the C plug is connected to one end of the coil of the relay in the hub B, the other end of the coil is connected to the third pin of the D plug, after the second pin and the fourth pin of the C plug are short-circuited, they are connected to the second pin and the fourth pin of the D plug (the second pin and the fourth pin of the D plug are also short-circuited). The third pin of the C plug is vacant, and the first pin of the D plug is vacant.

[0038] Referring to Figure 4, the energy storage inverter adapted to the parallel operation connection device according to the embodiment of the present application includes jacks adapted to the plugs C and D, and in addition to the three electrical connection lines of G, L, and N, it has four signal lines, and the connection method of these four signal lines is that the first pin is connected to VCC (for example, 12V), the second pin and the third pin are connected and simultaneously grounded, and the fourth pin is connected to the internal detection circuit. Here, as shown in Figure 5, the detection circuit is connected to the input pin of the CPU (not shown) and transmits the detection signal Vin_par, which is a signal for detecting that it is connected to the line, to the CPU for detection.

[0039] As shown in Figure 3, since the a, b, and c ends of the C plug and the D plug are commonly connected to the 1, 2, and 3 ends (the three lines of G, N, and L) of the hub B, when the A plug is inserted into the commercial power outlet, the commercial power lines connected by the a / b / c ends of the C plug and the D plug are the same, and when the energy storage inverters are operating in parallel, it can be ensured that both the L / N lines are correctly connected, and there is no need to consider the phase sequence problem.

[0040] Continuing to refer to Fig. 3, a relay K is connected to the L line of the hub B, and the ends of the coil of the relay K are respectively connected to the C plug and the D plug. The C plug and the D plug are designed with differentiation. Here, the first pin of the C plug is connected to one end of the coil of the relay, and the other end of the coil of the relay is connected to the third pin of the D plug. The second pin and the fourth pin of the C plug are short-circuited, the second pin and the fourth pin of the D plug are short-circuited, and the second pin of the C plug and the second pin of the D plug are connected. Since the input interface circuits of the two energy storage inverters are completely the same, regardless of whether C or D is inserted into which inverter, it is guaranteed that parallel operation is possible as long as they are connected to the two inverters. When the C plug and the D plug are respectively inserted into the 1# bidirectional energy storage inverter and the 2# bidirectional energy storage inverter, the first pin VCC of the 1# is connected to the second pin and the third pin of the 2# inverter through the first pin of the plug C, the coil of the relay K, and the third pin of the plug D, and further connected to the second pin of the plug C through the second pin of the plug D, and finally returns to the second pin of the 1#, forming a control loop. It is in a serial connection form. If the cord material of one inverter drops off (is cut off from the plug C / D) or the cord is pulled out artificially, the commercial power of the two inverters will be cut off at the same time. Also, the commercial power is cut off at the plug port, and there is no risk of electric shock caused by the floating plug in the air. The risk of damage to the inverter caused by the abnormality of a single machine in the commercial power input during parallel operation is also avoided. During parallel operation, the commercial power input is made the same. For example, in the case of the A plug, different terminals can be equipped according to different markets. Without considering the phase sequence problem of the two inverters, if it is connected to this parallel operation connection device, the commercial power input with the same frequency and the same phase in the two inverters can be realized.And only when two inverters can be connected to plugs C and D respectively, the control switch (for example, relay K) can be turned on. When the switch is turned on, the commercial power line reaching the 1# energy storage inverter from hub B via plug C and the commercial power line reaching the 2# energy storage inverter from hub B via plug D can be conducted, and the connection condition of the commercial power input in the parallel operation is satisfied. At this time, if the A plug is inserted into the commercial power socket, the two energy storage inverters can be powered on simultaneously.

[0041] In the parallel operation equipment according to the embodiment of the present application, one detection circuit is provided in each of the two energy storage inverters. Specifically, in the 1# energy storage inverter, the first end is connected to the fourth interface (the fourth pin) of the 1# energy storage inverter, and the second end is connected to the CPU to detect whether the 1# energy storage inverter is connected to the commercial power line, for example, whether it is connected to the first connector. A first detection circuit is provided. In the 2# energy storage inverter, the first end is connected to the fourth interface (the fourth pin) of the 2# energy storage inverter, and the second end is connected to the CPU to detect whether the 2# energy storage inverter is connected to another commercial power line, for example, whether it is connected to the second connector. A second detection circuit is provided. When connecting the first connector to the 1# energy storage inverter, the fourth signal line of the first connector is connected to the fourth interface (the fourth pin) of the 1# energy storage inverter, providing an identification signal indicating that it is connected to the first connector to the 1# energy storage inverter. After this identification signal is input into the first detection circuit, the first detection circuit outputs a signal characterizing that the 1# energy storage inverter is connected to the first connector to the CPU. Similarly, when connecting the second connector to the 2# energy storage inverter, the fourth signal line of the second connector is connected to the fourth interface (the fourth pin) of the 2# energy storage inverter, providing an identification signal indicating that it is connected to the second connector to the 2# energy storage inverter. After this identification signal is input into the second detection circuit, the second detection circuit outputs a signal characterizing that the 2# energy storage inverter is connected to the second connector to the CPU.

[0042] In some embodiments, the first detection circuit and the second detection circuit have the same circuit configuration. Referring to FIG. 5, the detection circuit in the energy storage inverter mainly consists of a PNP type transistor Q1, a resistor R1 (several Ω), a resistor R2 (10KΩ pull-up 3.3V), a capacitor C1, a diode D1, and a transient voltage suppressor TVS1. Port 4 of the detection circuit is connected to the fourth pin of the energy storage inverter, and Vin_par is connected to the input pin of the CPU. When the parallel operation connection device is not connected to the energy storage inverter, the fourth pin of the energy storage inverter floats in the air and Q1 is in the off state. At this time, Vin_par is at a high level. Referring to FIGS. 3 and 4, when no plug (here plug C or D) is connected to any energy storage inverter, the fourth pin of the energy storage inverter floats in the air, Q1 is in the off state, at this time Vin_par is at a high level, and the CPU can determine based on this that the energy storage inverter is not connected to the commercial power line. Conversely, when a plug (here plug C or D) is inserted into one energy storage inverter, the second pin and the fourth pin are short-circuited inside the energy storage inverter, the signal of the fourth pin of the energy storage inverter is pulled down to GND, Q1 turns on, and Vin_par, which was originally at a high level, becomes at a low level and is transmitted to the CPU for detection. When the CPU detects the low level, it confirms the connection of the commercial power input line. That is, after plugs C and D of the parallel operation connection device are respectively fitted into two energy storage inverters, the detection circuits of both energy storage inverters detect the connection of the commercial power line. In this case, the parallel operation mode can be entered. At this time, if the A plug is inserted into the commercial power socket, there is a commercial power input with the same frequency and the same phase in the two energy storage inverters.

[0043] In another embodiment, as the fourth pin of the plug C, it may be changed from the form of being connected to the second pin described above to the form of being connected to the first pin. Similarly, as the fourth pin of the plug D, it may be changed to the form of being connected to the first pin. Corresponding to this, the detection circuit is adjusted to change Q1 to an NPN type triode. In this case, when the energy storage inverter is connected to the plug (plug C or D), the fourth pin in the energy storage inverter is pulled up to VCC (high level), Q1 is turned on, and Vin_par, which was originally at the high level, becomes at the low level and is transmitted to the CPU for detection. Also with such a connection form and the detection circuit, it is similarly possible to detect whether the energy storage inverter is connected to the connector or not.

[0044] The above has described the present application in more detail with reference to specific preferred embodiments, and it is not considered that the specific implementation of the present application is limited only to these descriptions. For those skilled in the art, on the premise of not departing from the concept of the present application, some equivalent substitutions or obvious modifications can be made, and moreover, these have the same performance or use, and all should be regarded as belonging to the protection scope of the present application.

Claims

1. A control switch, a hub, a first connector, and a second connector are provided. The hub is connected between an AC power supply and the first connector and the second connector, and forms two identical AC lines, both of which are controlled to be turned on and off by the control switch. The first connector is configured to be adaptively connectable to a first energy storage inverter, and the second connector is configured to be adaptively connectable to a second energy storage inverter. The connection of the control switch is such that when the first connector is connected to the first energy storage inverter and the second connector is connected to the second energy storage inverter, the control switch turns on to simultaneously conduct the two AC lines; when the connection between the first connector and the first energy storage inverter is disconnected and / or the connection between the second connector and the second energy storage inverter is disconnected, the control switch turns off to simultaneously disconnect the two AC lines. A parallel operation connection device is characterized by this configuration.

2. The hub incorporates a current collector line, and a switch portion of the control switch for controlling the on / off of the current collector line is connected to the current collector line. The first end of the current collector line is connected to an AC power supply, the second end of the current collector line is connected to an electrical connection line of the first connector to form a first AC line, and the second end of the current collector line is further connected to an electrical connection line of the second connector to form a second AC line. The first AC line and the second AC line are the two identical AC lines. The parallel operation connection device according to Claim 1 is characterized by this.

3. The electrical connection lines of the first connector and the second connector are both three in number, and respectively correspond to a live wire, a neutral wire, and an earth wire. The parallel operation connection device according to Claim 2 is characterized by this.

4. Both the first connector and the second connector have signal lines respectively connected to both ends of the control unit of the control switch. When the first connector is connected to the first energy storage inverter and the second connector is connected to the second energy storage inverter, both ends of the control unit of the control switch form a control loop through the signal line of the first connector, the internal circuit of the first energy storage inverter, the internal circuit of the second energy storage inverter, and the signal line of the second connector, and control the control switch to turn on. The parallel operation connection device according to claim 1, characterized in that.

5. If there is a connector among the first connector and the second connector that is not connected to the energy storage inverter, both ends of the control unit of the control switch do not form a control loop through the signal line of the first connector, the internal circuit of the first energy storage inverter, the internal circuit of the second energy storage inverter, and the signal line of the second connector, and the control unit of the control switch loses power and turns off the switch unit of the control switch. The parallel operation connection device according to claim 4, characterized in that.

6. Both the first connector and the second connector have a first signal line, a second signal line, and a third signal line. One end of the control unit of the control switch is connected to the first signal line of the first connector, and the other end is connected to the third signal line of the second connector. The second signal line of the first connector is connected to the second signal line of the second connector. When connecting the connector to the energy storage inverter, the first signal line, the second signal line, and the third signal line are respectively connected corresponding to the first interface, the second interface, and the third interface of the energy storage inverter. Among them, the first interface and the second interface of the energy storage inverter are respectively the power supply terminal and the ground terminal of the energy storage inverter, and the second interface of the energy storage inverter is connected to the third interface. The parallel operation connection device according to claim 4, characterized in that.

7. Both the first connector and the second connector further have a fourth signal line. Inside the connector, the fourth signal line is connected to the second signal line. When connecting the connector to the energy storage inverter, the fourth signal line is connected to the fourth interface of the energy storage inverter to provide an identification signal indicating that it is connected to the connector to the energy storage inverter. The parallel operation connection device according to claim 6, characterized in that.

8. The control switch is a relay. The control switch includes a contact group connected to the current collector line of the hub to control the on / off of the current collector line, and a control coil with one end connected to the first signal line of the first connector and the other end connected to the third signal line of the second connector. The parallel operation connection device according to claim 6, characterized in that.

9. The first connector is a plug fitted to the first energy storage inverter, and the second connector is a plug fitted to the second energy storage inverter. The parallel operation connection device according to claim 1, characterized in that.

10. The hub, the first connector, and the second connector are integrally formed and provided. The parallel operation connection device according to claim 1, characterized in that.

11. The parallel operation connection device according to claim 1, further comprising a plug for connecting an AC power source, one end of which is insertable into an AC power outlet and the other end of which is connected to the hub.

12. A parallel operation facility, comprising: the parallel operation connection device according to any one of claims 1 to 11; a first energy storage inverter and a second energy storage inverter connected to the parallel operation connection device.

13. The parallel operation facility according to claim 12, wherein the first energy storage inverter is provided with a first detection circuit for detecting whether the first energy storage inverter is connected to one of the two same AC lines, and the second energy storage inverter is provided with a second detection circuit for detecting whether the second energy storage inverter is connected to the other of the two same AC lines.

Images