Energy storage system open-phase protection circuit and electronics

Abstract

The utility model discloses a kind of energy storage system open-phase protection circuit and electronic device.Wherein energy storage system open-phase protection circuit includes AC unit;Sampling unit is coupled to the AC unit, for collecting and monitoring the phase voltage of the AC unit;Control unit is coupled to the sampling unit, for when sampled phase voltage exceeds the reference AC voltage, generating tripping instruction;Switching component is coupled between the AC unit and the control unit, for disconnecting the input of the AC unit based on the tripping instruction.The utility model technical scheme can realize the power detection and control protection linkage of energy storage system, improve the reliability and security of product.

Description

Technical Field

[0001] This utility model relates to the field of energy storage system technology, and in particular to an energy storage system phase loss protection circuit and an electronic device. Background Technology

[0002] With the improvement and development needs of energy storage systems, the lithium battery chemical system-based power energy storage industry has developed rapidly.

[0003] Because lithium batteries in energy storage systems store a large amount of energy, these systems require monitoring and protection to prevent damage and safety incidents to subsequent power loads. Current technologies typically use electricity meters to collect and monitor the three-phase AC power in the energy storage system, but these methods only provide monitoring and lack corresponding protection functions. Utility Model Content

[0004] The main purpose of this invention is to provide a phase loss protection circuit for an energy storage system and an electronic device, which aims to improve the stability and safety of the energy storage system's power supply to the load.

[0005] To achieve the above objectives, the present invention proposes a phase loss protection circuit for an energy storage system, comprising: an AC power unit; a sampling unit electrically connected to the AC power unit for acquiring and monitoring the phase voltage of the AC power unit; a control unit electrically connected to the sampling unit for comparing the sampled phase voltage with a reference AC voltage, and generating a trip command when the sampled phase voltage exceeds the reference AC voltage; and a switching assembly coupled between the AC power unit and the control unit for disconnecting the input of the AC power unit based on the trip command.

[0006] Optionally, the switching assembly includes: an intermediate relay coupled to the control unit for connecting the circuit within the intermediate relay based on the tripping command; and a switching unit coupled between the intermediate relay and the AC unit.

[0007] Optionally, the switching unit includes: a trip unit, one end of which is electrically connected to the neutral wire in the AC unit, and the other end of which is electrically connected to an intermediate relay; and an AC switch connected to the AC switch, one end of which is electrically connected to the AC unit, and the other end of which is electrically connected to the load.

[0008] Optionally, the trip unit is configured to trip the AC switch in response to the mains voltage supply and the trip command when the intermediate relay is turned on; the AC switch is configured to disconnect the AC auxiliary power main circuit of the AC power unit.

[0009] Optionally, the control unit is configured to: filter the sampled phase voltage to obtain a filtered phase voltage; and compare the filtered phase voltage with a reference AC voltage, wherein the reference AC voltage is the maximum voltage required for normal operation of the load.

[0010] Optionally, the control unit is a battery management system, and the sampling unit is electrically connected to the first sampling port and the second sampling port of the battery management system, respectively.

[0011] Optionally, the intermediate relay is electrically connected to the first output port and the second output port of the battery management system, respectively.

[0012] Optionally, the sampling unit is an AC energy meter and / or the reference AC voltage is 260-280V.

[0013] Optionally, the switching circuit is electrically connected to the load and is used to cut off the input of the AC unit to the load according to the cooperation of the control unit and the intermediate relay. This invention also proposes an electronic device, which includes the energy storage system phase loss protection circuit described above.

[0014] This utility model's technical solution involves setting up a control unit and a sampling unit. The sampling unit collects and monitors the phase voltages in the AC power unit. The control unit compares the phase voltages collected by the sampling unit with a reference voltage. When the phase voltage exceeds the reference voltage, a trip command is generated to control the switching components, thereby controlling the input of the AC power unit and tripping the AC auxiliary power main circuit of the AC power unit. This protects the load powered by the energy storage system and enables the linkage of monitoring and control protection of the phase loss protection circuit of the energy storage system, improving the reliability and safety of the product. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a vector diagram of the three-phase AC power supply for an energy storage system.

[0017] Figure 2 This is a schematic diagram of the phase loss protection circuit of the energy storage system of this utility model; Figure 3 This is a schematic diagram of the circuit structure of an embodiment of the phase loss protection circuit of the energy storage system of this utility model; Figure 4 This is a flowchart illustrating the protection logic in the phase loss protection circuit of the energy storage system of this utility model.

[0018] Explanation of icon numbers: 10. Phase loss protection circuit for energy storage system; 20. Load; 110. Alternating current unit; 120. Sampling unit; 121. AC power meter; 130: Control unit; 131: Battery management system; 140: Switch assembly; 141: Intermediate relay; 142: Switching unit; 1421: Trip unit; 1422: AC switch A, Phase A power supply; B, Phase B power supply; C, Phase C power supply; N, Neutral wire; PE, Safety wire; S31-S34: Steps of the protection logic for the phase loss protection circuit of the energy storage system.

[0019] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0022] Energy storage systems, such as lithium-ion battery chemistry-based circuit energy storage systems, can be used to power various loads in industrial, commercial, and transportation sectors. Examples of such systems include those powering fire emergency lighting, charging piles, rail emergency equipment, liquid coolers, and combiner cabinets. Due to the large energy storage capacity of lithium-ion batteries, when applied to various loads, the energy storage system may experience problems when the leading phase of the three-phase AC (380V) power supply fails. Figure 1As shown, this will lead to Figure 1 Voltage imbalance between phases A, B, and C can cause any one of phases UA, UB, and UC to exceed 220V, resulting in a load voltage exceeding 220V and potentially causing load failure and electrical safety accidents. Current technology collects voltage data (UA, UB, and UC) from phases A, B, and C using an energy meter. This data is then used to monitor the three-phase AC power supply in the energy storage system. However, while this technology monitors the data, it lacks corresponding safety logic protection for this collected data. This lack of a safety protection mechanism for the downstream load increases the risk of electrical safety accidents, reducing the safety and reliability of the energy storage system.

[0023] In response, this utility model proposes a phase loss protection circuit 10 for an energy storage system, which can be applied to an energy storage system to monitor and protect the three-phase AC power of the energy storage system.

[0024] like Figure 2 and Figure 3 As shown, Figure 2 This is a schematic diagram of a module of an embodiment of the phase loss protection circuit of the energy storage system of this utility model. Figure 3 This is a schematic diagram of the specific circuit structure of an embodiment of the phase loss protection circuit of the energy storage system of this utility model. The phase loss protection circuit 10 of the energy storage system may include, for example, an AC power unit 110, a sampling unit 120, a control unit 130, and a switching assembly 140.

[0025] Specifically, the sampling unit 120 is coupled to the AC power unit 110, and the sampling unit 120 is used to collect and monitor the phase voltages of the AC power unit 110. The control unit 130 is coupled to the sampling unit 120, and the control unit 130 is used to compare the phase voltages sampled by the sampling unit 120 with a reference AC voltage. When the sampled phase voltage exceeds the reference AC voltage, a trip command is generated. The switching assembly 140 is coupled between the AC power unit 110 and the control unit 130, and is used to disconnect the input of the AC power unit 110 based on the trip command.

[0026] The AC power unit 110 can be, for example, a three-phase AC power supply section in an energy storage system, such as... Figure 3As shown, it may include, for example, phase A, phase B, phase C, phase N, and PE. Phases A, B, and C can be, for example, the three live wires of a three-phase AC power supply in an energy storage system, which are yellow, green, and red respectively, and can be used to power symmetrical loads such as industrial motors and high-power equipment. Phase N is the lead-out line of the neutral point of the three-phase power supply in the energy storage system, also called the zero line, which mainly provides single-phase 220V voltage, such as mains voltage. The PE terminal is a grounding conductor, which can prevent electric shock and eliminate static electricity and electromagnetic interference.

[0027] The sampling unit 120 may be, for example, an electricity meter, which may be an existing type of electricity meter. The electricity meter is electrically connected to phases A, B, and C of the AC power unit 110 to collect the voltage of each phase in the AC power unit 110 in real time, obtaining the voltages UA, UB, and UC, so as to facilitate subsequent real-time monitoring of the voltages of phases A, B, and C. The data collected by the sampling unit 120 may be uploaded to a BMS (Battery Management System) for example, so that the voltage of each phase of the AC power unit 110 can be monitored in real time by the BMS.

[0028] The control unit 130 may be, for example, a battery management system or a control circuit, etc. The control unit 130 may be communicatively connected to the sampling unit 120, and the BMS can collect the phase voltage values ​​of the energy meter through the energy meter's port. Figure 3 As shown, the BMS can, for example, collect the phase voltage values ​​of the energy meter via the sampling ports 485A and / or 485B of the energy meter. Then, each phase voltage is compared with a reference AC voltage, which can be, for example, the maximum voltage at which load 20 can operate normally, such as 260V AC. When the voltage of any one of phases UA, UB, and UC exceeds the maximum voltage (i.e., UA / UB / UC > 260VAC), the BMS generates a trip command, which may include control signals.

[0029] The switching assembly 140 may include, for example, a relay and a switching unit. The relay may be, for example, an intermediate relay as in the prior art. The switching unit may include, for example, a trip unit and an AC main switch. The trip unit is electrically connected to the relay, and the other end of the relay is electrically connected to the C-phase wire. The other end of the trip unit is electrically connected to the N-phase wire, so that the trip unit and the relay form a closed circuit. The trip unit can receive 220V power supply from the C / N phases, thereby mechanically tripping the AC main switch and causing the AC auxiliary power main circuit of each phase's AC incoming line to be disconnected.

[0030] In an embodiment of this utility model, the specific working process of the phase loss protection circuit 10 of the energy storage system is as follows: Reference Figure 4 , Figure 4 This is a flowchart of the protection logic of the phase loss protection circuit 10 of the energy storage system.

[0031] First, sampling unit 120 samples the voltage values ​​UA, UB, and UC of phases A, B, and C in AC unit 110. Then, control unit 130 receives UA, UB, and UC through the communication port of sampling unit 120 and compares them with a reference AC voltage of 260VAC. When any value of UA, UB, or UC exceeds 260VAC, control unit 130 outputs a trip command to intermediate relay 141, which includes a 24V DC control signal. Upon receiving the 24V DC control signal, intermediate relay 141 closes internally, allowing switch unit 142 to receive 220V AC mains power from phases C and N. This causes switch unit 142 to trip, providing overvoltage protection to load 20 within 5 seconds of tripping. This achieves the protection of the load.

[0032] The technical solution of this utility model sets up a control unit 130 and a sampling unit 120. The sampling unit 120 collects and monitors the phase voltage of each phase in the three-phase AC unit. The control unit 130 compares the phase voltage collected by the sampling unit with the reference voltage. When the phase voltage exceeds the reference voltage, it generates a trip command to control the intermediate relay 141 and the switching unit 142, thereby controlling the input of the AC unit. This can protect the subsequent load, thereby realizing the linkage of monitoring and control protection of the phase loss protection circuit 10 of the energy storage system, improving the reliability and safety of the power supply of the system.

[0033] Further, see Figure 2 and Figure 3 The switching assembly 140 may include, for example, an intermediate relay 141 and a switching unit 142. The intermediate relay 141 is coupled to the control unit 130 and is used to activate the circuit within the intermediate relay 141 based on the tripping command. The switching unit 142 is coupled between the intermediate relay 141 and the AC power unit 110.

[0034] Specifically, the intermediate relay 141 can be, for example, a relay used in the prior art, and can be composed of a coil, an armature, a spring, and a contact assembly. The coil can receive a small current control signal, such as a 24V DC control signal or a 220V AC control signal. When the coil is energized, the coiled magnetic force attracts the armature, causing the intermediate relay 141 to close and conduct. When the power is off, it is reset by the spring. The contact assembly can include, for example, normally open, normally closed, and a common terminal. These contacts achieve circuit switching through mechanical linkage. The intermediate relay can close itself and conduct the circuit by receiving a trip command containing a 24V DC control signal. The intermediate relay 141 can serve as a safety interlock circuit, further improving the linkage between monitoring and control protection of the phase loss protection circuit 10 of the energy storage system.

[0035] Further, see Figure 3 The switching unit 142 may include, for example, a trip unit 1421 and an AC switch 1422, with the trip unit 142 connected to the AC switch 142. One end of the AC switch 1422 is electrically connected to the AC power unit 110, and the other end is electrically connected to the load 20. One end of the trip unit 1421 is electrically connected to the N-phase wire in the AC power unit 110, and the other end is electrically connected to an intermediate relay 141. The trip unit 142 may be, for example, an electromagnetic trip unit, a thermal trip unit, a thermomagnetic trip unit, or a shunt trip unit, etc., as is available in the prior art. Of course, in this embodiment of the invention, the trip unit 1421 may be a shunt trip unit, which has a short response time and can be applied to various emergency shutdown situations. The AC switch 1422 may be, for example, suitable for the main AC switch of a three-phase AC power supply in an energy storage system. By cooperating with the electrical connection between the trip unit 1421 in the switching unit 142 and the AC switch 1422, voltage protection for the load 20 is achieved, preventing voltage drift caused by a phase loss in the three-phase AC power of the energy storage system, which would cause the phase voltage to exceed the maximum voltage for normal operation of the load 20, thereby causing the equipment to burn out.

[0036] Furthermore, the trip unit 1421 is configured to: upon receiving a trip command and 220V power supply (i.e., mains voltage) for the C / N phase after the intermediate relay 141 is turned on or closed, trip the AC switch 1422; the AC switch 1422 is configured to: trip the AC auxiliary power main circuit of the AC power unit 110. This further enables voltage protection of the load 20 by the energy storage system.

[0037] Furthermore, the control unit 130 is configured to: filter the sampled phase voltage to obtain a filtered phase voltage; and compare the filtered phase voltage with the reference AC voltage. The filtering process takes 3 seconds, where the reference AC voltage is the maximum voltage required for normal operation of the load 20. By filtering the sampled phase voltage, false triggering due to voltage fluctuations can be suppressed, improving the accuracy of the protection circuit.

[0038] Furthermore, the control unit 130 is a battery management system 131, and the sampling unit 120 is electrically connected to the first sampling port and the second sampling port of the battery management system 131. The first sampling port can be, for example, a 485A port, and the second sampling port can be, for example, a Wi-Fi 485B port. The 485A and 485B ports in the battery management system 131 are differential signal pairs in the RS-485 communication protocol. The sampling unit 120 reuses existing BMS port resources, which can reduce hardware costs and eliminate the need for a separate controller.

[0039] Furthermore, the intermediate relay 141 is electrically connected to the first output port and the second output port of the battery management system 131. The first output port is a +24V port, and the second output port is a -24V port. That is, the first and second output ports can serve as the power supply terminals for the intermediate relay 141, with the +24V port being the positive power supply port and the -24V port being the negative power supply port. This arrangement allows the BMS to provide a 24V DC control signal to the intermediate relay 141, or in other words, the BMS provides a 24V DC power supply to the intermediate relay 141, thereby causing the intermediate relay 141 to close and enabling the energy storage system phase loss protection circuit 10 to perform the next protection logic. This allows the intermediate relay 141 to act as a safety interlock circuit to further protect the load 20.

[0040] Furthermore, the sampling unit 120 is an AC energy meter 121. And / or, the reference AC voltage may be, for example, 260V-280V, such as 260V, 270V, or 280V. By reusing the sampling unit 120 as an existing energy meter resource, hardware usage costs can be reduced, and the problem of the energy meter being used only for monitoring purposes can be solved. It can also be used in conjunction with a BMS to achieve protection functions.

[0041] Furthermore, the switching unit 142 is electrically connected to the load 20 and is used to cut off the input of the AC power unit 110 to the load 20 according to the cooperation of the control unit 130 and the intermediate relay 141. The load 20 may be, for example, a liquid chiller, fire-fighting equipment, or a combiner cabinet, etc.

[0042] In embodiments of this utility model, such as Figure 4 As shown, the specific working process of the phase loss protection circuit 10 of the energy storage system is as follows: First, the specific circuit structure of the phase loss protection circuit 10 of the energy storage system can be as follows: Figure 3 As shown.

[0043] S31. The AC energy meter collects the voltages of phases A, B, and C to obtain UA, UB, and UC; The voltage values ​​of each phase, UA, UB, and UC, are monitored using an AC power meter.

[0044] S32. The battery management system receives UA, UB and UC, and determines whether the voltage of any one of them is greater than 260V; The BMS collects the phase voltage values ​​UA, UB, and UC of the AC energy meter through the 485A / 485B communication port. The filtering time is 3 seconds. When an overvoltage occurs (UA / UB / UC > 260VAC), the BMS outputs 24V+ / 24V- to power the coil of the intermediate relay within 2 seconds.

[0045] S33, The battery management system generates a trip command and sends it to the intermediate relay; The BMS outputs a 24V DC control signal to power the coil of the intermediate relay. After the intermediate relay is energized, it closes, allowing the shunt trip unit to receive 220V AC mains power from the C / N phase.

[0046] S34. The trip unit receives the trip command and controls the AC switch to trip and open.

[0047] After receiving 220V AC mains power from the C / N phases, the shunt trip unit trips the AC switch, providing overvoltage protection for the load in a total duration of 5 seconds. Simultaneously, the AC switch trips the AC auxiliary power main circuit of the AC incoming switch.

[0048] This utility model embodiment achieves improved reliability and safety protection of the load by the energy storage system through the above-described process steps.

[0049] This invention also proposes an electronic device that includes the energy storage system phase loss protection circuit 10 as described in the above embodiments. The energy storage system phase loss protection circuit 10 can be incorporated into various types of electronic devices that require power from different energy storage systems, such as computer power supplies, server power supplies, control equipment, or communication equipment, thereby improving the reliability and safety of the energy storage system's power supply to different loads.

[0050] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A phase loss protection circuit (10) for an energy storage system, characterized in that, include: Alternating current unit (110); A sampling unit (120) is coupled to the AC unit (110) and is used to collect and monitor the phase voltage of the AC unit (110); A control unit (130), coupled to the sampling unit (120), is used to generate a trip command when the sampled phase voltage exceeds the reference AC voltage; A switching assembly (140), coupled between the AC unit (110) and the control unit (130), is used to disconnect the input of the AC unit (110) based on the trip command.

2. The energy storage system phase loss protection circuit (10) according to claim 1, characterized in that, The switching assembly (140) includes: an intermediate relay (141) coupled to the control unit (130) for conducting the circuit within the intermediate relay (141) based on the tripping command; and a switching unit (142) coupled between the intermediate relay (141) and the AC unit (110).

3. The energy storage system phase loss protection circuit (10) according to claim 2, characterized in that, The switching unit (142) includes: a trip unit (1421), one end of which is electrically connected to the neutral wire in the AC unit (110), and the other end of which is electrically connected to an intermediate relay (141); and an AC switch (1422), which is connected to the trip unit (1421), one end of which is electrically connected to the AC unit (110), and the other end of which is electrically connected to a load (20).

4. The energy storage system phase loss protection circuit (10) according to claim 3, characterized in that, The trip unit (1421) is configured to trip the AC switch (1422) in response to the mains voltage supply and the trip command when the intermediate relay (141) is turned on; the AC switch (1422) is configured to trip the AC auxiliary main circuit of the AC power unit (110).

5. The energy storage system phase loss protection circuit (10) according to any one of claims 1-4, characterized in that, The control unit (130) is configured to: filter the sampled phase voltage to obtain a filtered phase voltage; and compare the filtered phase voltage with a reference AC voltage, wherein the reference AC voltage is the maximum voltage at which the load (20) operates normally.

6. The energy storage system phase loss protection circuit (10) according to any one of claims 2-4, characterized in that, The control unit (130) is a battery management system (131), and the sampling unit (120) is electrically connected to the first sampling port and the second sampling port of the battery management system (131).

7. The energy storage system phase loss protection circuit (10) according to claim 6, characterized in that, The intermediate relay (141) is electrically connected to the first output port and the second output port of the battery management system (131).

8. The energy storage system phase loss protection circuit (10) according to claim 7, characterized in that, The sampling unit (120) is an AC energy meter (121); and / or the reference AC voltage includes 260-280V.

9. The energy storage system phase loss protection circuit (10) according to claim 2, characterized in that, The switching unit (142) is electrically connected to the load (20) and is used to cut off the input of the AC unit (110) to the load (20) according to the cooperation of the control unit (130) and the intermediate relay (141).

10. An electronic device, characterized in that, The electronic device includes the energy storage system phase loss protection circuit (10) as described in any one of claims 1-9.

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