A control system suitable for an outdoor energy storage cabinet high-voltage box and a high-voltage box

Abstract

The present application relates to the technical field of outdoor energy storage, and particularly refers to a control system suitable for a high-voltage box of an outdoor energy storage cabinet, comprising: a high-voltage power distribution unit, a control unit, an auxiliary power supply unit, an insulation state detection unit and an operating state monitoring unit; wherein the high-voltage power distribution unit comprises a main loop switch and a protection unit connected in series in a direct-current main loop; the auxiliary power supply unit is a double-circuit AC / DC power supply, and an output end is connected to a power supply end of the control unit; a detection end of the insulation detection unit is connected to a battery pack, and an insulation signal is collected before starting and transmitted to the control unit; a monitoring end of the operating monitoring unit is connected to the direct-current main loop, and an abnormal signal is collected during operation and transmitted to the control unit. The control unit controls the on-off of the main loop switch unit and the main loop protection unit and the power supply switching of the auxiliary power supply unit, realizes multi-level protection redundancy, advance insulation detection, real-time abnormal monitoring, double-circuit power supply stability and black start, and improves the safety, stability and flexibility of the system.

Description

Technical Field

[0001] This invention relates to the field of outdoor energy storage technology, and in particular to a control system and a high-voltage box suitable for outdoor energy storage cabinets. Background Technology

[0002] As renewable energy continues to account for an increasing proportion of the global energy mix, energy storage products, as core equipment for balancing energy supply and demand and ensuring grid stability, are undergoing rapid iteration. The industry is placing higher demands on the operational safety, long-term stability, and scenario adaptability of energy storage systems. The high-voltage box, as the high-voltage central hub of the energy storage system, directly determines the safety boundary and availability efficiency of the entire system through its performance and reliability.

[0003] Currently, the control system of traditional energy storage cabinet high-voltage boxes mainly consists of three core modules, and the overall control logic and hardware layout have formed a relatively fixed scheme: First, the control and communication module, with the energy storage battery system control unit (BCU) as the core, is responsible for parsing operating instructions, executing charge and discharge switching control logic, and realizing data interaction with the energy storage converter (PCS) and the background monitoring system through the communication interface; Second, the auxiliary power supply module, which converts the high-voltage bus voltage into low-voltage secondary power through the DC / DC system power conversion unit to power control components such as the BCU and contactor coils; Third, the high-voltage power distribution unit, mainly composed of fuses (FU1, FU2, FU3), load disconnect switches (QB), DC contactors (KM1, KM2, KM3), pre-charge resistors (R), and current acquisition devices (HET), undertakes the functions of high-voltage current distribution, pre-charge control, and preliminary fault protection.

[0004] like Figure 1 As shown, its typical operating process is as follows: After the PCS is connected to the grid, the DC bus is energized, and the auxiliary power supply module generates a stable secondary power supply through the DC / DC converter, activating the energy storage cabinet system; the BCU then starts the system self-test, verifying key parameters such as voltage acquisition, current acquisition (HET), and contactor status. After the self-test passes, the system enters the charging and discharging preparation state; the BCU controls the DC contactors KM2 and KM3 to close, and the high voltage current precharges the circuit capacitor through the pre-charging resistor (R) to avoid large current surges; after the pre-charging process is completed, the BCU controls the DC contactor KM1 to close and the DC contactor KM3 to open, and the entire energy storage system officially enters the charging and discharging operation state; when the BCU detects a voltage / current over-threshold alarm or a short circuit fault during system operation, the BCU controls the opening of DC contactors such as KM1 and KM2, or triggers passive protection (fuses FU1 and FU2 blow), to cut off the high voltage circuit to ensure safety.

[0005] However, the control systems of traditional high-voltage energy storage cabinets still have multiple shortcomings in safety and reliability during actual operation, making it difficult to meet increasingly stringent energy storage safety standards.

[0006] Firstly, there is no insulation testing before commissioning, so it is impossible to determine the insulation performance of the battery pack and lines. Insulation failure can easily lead to increased leakage current, causing thermal runaway of the battery cells and fire.

[0007] Secondly, the switching of the DC circuit relies on the DC contactor, which has a short lifespan when cutting off power under load, and the contacts are prone to sticking together after multiple switching, leading to protection failure.

[0008] Thirdly, the protection mechanism of the main circuit relying on the combination of disconnecting switches and fuses has blind spots. The energy of small current overload is insufficient to trigger the fuse to blow, which accelerates the aging of the device.

[0009] Fourth, the lack of monitoring for high-temperature sparks and arcs makes it difficult to predict hidden risks such as poor contacts and loose wiring, which can easily lead to fire accidents.

[0010] Fifth, single-circuit power supply relies on DC / DC secondary power supply, which cannot achieve black start. When the external power supply is interrupted, the system is difficult to start automatically, reducing the availability in emergency and off-grid scenarios. Summary of the Invention

[0011] Therefore, the technical problem to be solved by this invention is to address the following issues in the application control system of traditional energy storage cabinet high-voltage boxes: lack of insulation testing before commissioning, which easily leads to insulation failure; reliance on DC contactors for load cutting, resulting in short lifespan and easy contact adhesion; blind spots in the protection mechanism of main circuit isolating switches and fuses for small current overloads; lack of monitoring for high-temperature sparks and arcs, making it difficult to predict hidden risks; and the inability of single-circuit power supply to achieve black start, reducing the availability of the scenario. Through modular upgrades and optimization of protection mechanisms, the invention ensures the safe and stable operation of the energy storage system throughout its entire life cycle.

[0012] To solve the above technical problems, the present invention provides a control system and a high-voltage box suitable for outdoor energy storage cabinets. The control system includes: a high-voltage power distribution unit, a control unit, an auxiliary power supply unit, an insulation status detection unit, and an operating status monitoring unit.

[0013] The high-voltage power distribution unit includes a main circuit switch unit and a main circuit protection unit. The main circuit protection unit and the main circuit switch unit are connected in series in the DC main circuit between the battery pack and the energy storage converter in the energy storage system.

[0014] The auxiliary power supply unit includes AC and DC dual power supply branches, and the output terminal of the AC and DC dual power supply branches is electrically connected to the power input terminal of the control unit.

[0015] The detection end of the insulation status detection unit is connected to the DC main circuit near the battery pack side, and its signal output end is electrically connected to the control unit. It is used to collect the insulation status signal of the battery pack before the energy storage system is started and transmit it to the control unit.

[0016] The monitoring terminal of the operation status monitoring unit is electrically connected to the DC main circuit of the energy storage system, and its signal output terminal is electrically connected to the control unit. It is used to collect abnormal status signals of the DC main circuit during the operation of the energy storage system and transmit them to the control unit.

[0017] The control output terminal of the control unit is electrically connected to the branch control terminals of the main circuit switch unit, the main circuit protection unit, and the auxiliary power supply unit, respectively, and is used to control the on / off state of the main circuit switch unit and the main circuit protection unit, as well as the switching of the AC / DC dual power supply branch, according to the insulation status signal and the abnormal status signal.

[0018] In one embodiment of the present invention, the main circuit switching unit includes a plurality of DC contactors, and the main circuit protection unit is a DC molded case circuit breaker, wherein the DC molded case circuit breaker and the plurality of DC contactors are connected in series in the DC main circuit.

[0019] In one embodiment of the present invention, when the control unit receives an abnormal status signal from the operating status monitoring unit, or receives a system voltage alarm signal, a system current alarm signal, or a short circuit current signal, it first outputs a disconnect signal to the DC molded case circuit breaker of the main circuit protection unit, and then outputs a disconnect signal to the DC contactor of the main circuit switching unit.

[0020] In one embodiment of the present invention, the insulation status detection unit is an insulation detection module. The detection end of the insulation detection module is connected to the positive and negative busbars of the battery pack through a wire, and is used to collect the insulation resistance value of the battery pack and transmit the insulation resistance value as the insulation status signal to the control unit.

[0021] In one embodiment of the present invention, the operating status monitoring unit is an arc monitoring module. The monitoring end of the arc monitoring module is sleeved on the conductor of the DC main circuit and is used to collect abnormal arc signals in the DC main circuit and transmit the abnormal arc signals as the abnormal status signals to the control unit.

[0022] In one embodiment of the present invention, the AC / DC dual power supply branch includes a DC power supply branch and an AC power supply branch. The input end of the DC power supply branch is connected to the DC bus of the battery pack, and its output end is connected to the power input end of the control unit. The input end of the AC power supply branch is connected to an AC power source, and its output end is connected in parallel with the DC power supply branch and connected to the power input end of the control unit.

[0023] In one embodiment of the present invention, the DC power supply branch is connected in series with a first branch circuit breaker, and the AC power supply branch is connected in series with a second branch circuit breaker. The control terminals of the first branch circuit breaker and the second branch circuit breaker are respectively electrically connected to the control output terminal of the control unit.

[0024] In one embodiment of the present invention, the control unit has a built-in self-test module. The signal input terminal of the self-test module is electrically connected to the output terminal of the auxiliary power supply unit. The self-test module is used to collect the status parameters of the energy storage system and generate a self-test signal after the auxiliary power supply unit is started. The self-test signal is transmitted to the signal processing terminal of the control unit.

[0025] In one embodiment of the present invention, after receiving a self-test pass signal transmitted by the self-test module, the control unit outputs a start signal to the insulation status detection unit; after receiving a self-test fail signal, it outputs a hold signal to the auxiliary power supply unit and outputs a fault signal to the external communication interface.

[0026] In one embodiment of the present invention, the high-voltage power distribution unit further includes a pre-charging unit, which includes a pre-charging resistor and a pre-charging switch. The pre-charging switch and the pre-charging resistor are connected in series and then connected in parallel across the two ends of the main circuit switch unit.

[0027] In one embodiment of the present invention, the control terminal of the precharge switch is electrically connected to the control output terminal of the control unit. After the control system enters the charging and discharging preparation state, the control unit first outputs a closing signal to the precharge switch. After the precharge duration reaches a preset value, it outputs a disconnect signal to the precharge switch and outputs a closing signal to the DC contactor of the main circuit switch unit.

[0028] In addition, the present invention also provides a high-voltage box for an outdoor energy storage cabinet, including a box body and the control system, wherein the control system is placed inside the box body.

[0029] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0030] This invention introduces an insulation detection module to detect the insulation status of the energy storage system before startup, overcoming the deficiency of traditional technologies that lack insulation detection before startup. It utilizes a multi-level protection redundancy mechanism constructed by the cooperation of DC molded case circuit breakers and DC contactors, solving the problems of short lifespan and contact adhesion caused by traditional reliance on DC contactors for load-bearing disconnection, and the inability of fuses to handle small current overloads. The newly added operation monitoring module can identify abnormal arcs during operation in real time, avoiding the hidden dangers of traditional technologies failing to detect high-temperature sparks and arcing in a timely manner. The adoption of a dual AC / DC power supply redundancy scheme not only ensures stable system power supply but also enables the energy storage system to have a black-start function, overcoming the limitation of traditional single-circuit power supply requiring external power supply for self-starting. Overall, it significantly improves the safety, stability, and applicability of the control system for outdoor energy storage cabinets and high-voltage boxes. Attached Figure Description

[0031] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0032] Figure 1 This is a schematic diagram of the structure of a traditional energy storage cabinet high-voltage box application control system;

[0033] Figure 2 This is a schematic diagram of the structure of a control system for an outdoor energy storage cabinet high-voltage box provided in an embodiment of the present invention;

[0034] Figure 3 This is an electrical connection diagram of a control system for an outdoor energy storage cabinet high-voltage box provided in an embodiment of the present invention;

[0035] Figure 4 This is a structural schematic diagram of the high-voltage box of an outdoor energy storage cabinet provided in an embodiment of the present invention;

[0036] Explanation of reference numerals in the accompanying drawings: 1. Enclosure; 11. High-voltage power distribution unit; 111. Main circuit switch unit; 112. Main circuit protection unit; 113. Pre-charge unit; 12. Control unit; 13. Auxiliary power supply unit; 14. Insulation status detection unit; 15. Operating status monitoring unit; 100. Battery pack; 200. Energy storage converter. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0038] Reference Figure 2 and Figure 3As shown, the present invention addresses the safety, reliability, and scenario adaptability issues of high-voltage boxes in outdoor energy storage systems by providing a control system suitable for high-voltage boxes in outdoor energy storage cabinets, comprising: a high-voltage power distribution unit 11, a control unit 12, an auxiliary power supply unit 13, an insulation status detection unit 14, and an operating status monitoring unit 15.

[0039] The high-voltage power distribution unit 11 includes a main circuit switch unit 111 and a main circuit protection unit 112. The main circuit protection unit 112 and the main circuit switch unit 111 are connected in series in the DC main circuit between the battery pack 100 and the energy storage converter 200 (PCS) in the energy storage system.

[0040] The auxiliary power supply unit 13 includes AC and DC dual power supply branches, and the output terminals of the AC and DC dual power supply branches are electrically connected to the power input terminals of the control unit 12 and the high-voltage power distribution unit 11.

[0041] The detection end of the insulation state detection unit 14 is connected to the DC main circuit near the battery pack 100, and its signal output end is electrically connected to the control unit 12. It is used to collect the insulation state signal of the battery pack 100 before the energy storage system is started and transmit it to the control unit 12.

[0042] The monitoring terminal of the operation status monitoring unit 15 is electrically connected to the DC main circuit of the energy storage system, and its signal output terminal is electrically connected to the control unit 12. It is used to collect abnormal status signals of the DC main circuit during the operation of the energy storage system and transmit them to the control unit 12.

[0043] The control output terminal of the control unit 12 is electrically connected to the branch control terminals of the main circuit switch unit 111, the main circuit protection unit 112, and the auxiliary power supply unit 13, respectively, and is used to control the on / off state of the main circuit switch unit 111 and the main circuit protection unit 112, and to control the switching of the AC / DC dual power supply branches according to the insulation status signal and the abnormal status signal.

[0044] Furthermore, the high-voltage power distribution unit 11 is the core control and protection module of the DC main circuit of the energy storage system (connecting the battery pack 100 and the PCS energy storage converter 200), including a main circuit switching unit 111, a main circuit protection unit 112, and a pre-charging unit 113, with the specific structure and connection as follows:

[0045] The main circuit switch unit 111 includes at least two DC contactors, and the main circuit protection unit 112 is a DC molded case circuit breaker. The DC molded case circuit breaker and the two DC contactors are connected in series in the DC main circuit.

[0046] Optionally, the main circuit switching unit 111 consists of a DC contactor KM1 and a DC contactor KM2. The DC contactor KM1 is located on the positive bus of the DC main circuit and is connected in series between the positive terminal B+ of the battery pack 100 and the positive terminal P+ of the energy storage converter 200. The DC contactor KM2 is located on the negative bus of the DC main circuit and is connected in series between the negative terminal B- of the battery pack 100 and the negative terminal P- of the energy storage converter 200, forming a key on / off node for the main circuit current transmission.

[0047] The coil terminals of both DC contactors KM1 and KM2 are reliably connected to the relay control output terminal of the control unit 12. By receiving the on / off control commands issued by the control unit 12 according to the system operating status (such as self-test results, pre-charge progress, and fault signals), the switching of the main circuit switch state is accurately realized, ensuring that the power transmission of the DC main circuit meets the system's charging and discharging control requirements.

[0048] Optionally, the main circuit protection unit 112 adopts a DC molded case circuit breaker QF1 with shunt trip, which is installed on the positive bus of the DC main circuit and connected in series between the positive terminal P+ of the DC contactor KM1 and the energy storage converter 200, replacing the protection mechanism of the disconnecting switch and fuse in the traditional high-voltage box. The shunt trip terminal of the DC molded case circuit breaker QF1 is electrically connected to the MOCB control output terminal of the control unit 12, and can be actively controlled to disconnect by the control unit 12; at the same time, the DC molded case circuit breaker QF1 has a dual protection mechanism of active disconnection by receiving the control signal of the control unit 12 and passive disconnection by automatically tripping when encountering overcurrent / short circuit, forming protection redundancy with the DC contactor and avoiding the contact sticking problem caused by the contactor disconnecting under load.

[0049] The pre-charge unit consists of a pre-charge resistor R and a pre-charge switch (in this embodiment, a DC contactor KM3) connected in series, and is connected in parallel across the two ends of the DC contactor KM1 in the main circuit switch unit 111. The control terminal of the DC contactor KM3 is electrically connected to the relay control output terminal of the control unit 12, which is used to limit the pre-charge current in the early stage of system startup to avoid large current impacting the capacitor on the 200PCS side of the energy storage converter.

[0050] In addition, the DC main circuit includes a current acquisition device (HET) connected in series between the DC contactor KM2 and the negative terminal B- of the battery pack 100; the signal output terminal of the current acquisition device (HET) is electrically connected to the current acquisition input terminal of the control unit 12, and the current value of the main circuit is acquired in real time, providing data support for the overcurrent alarm and charge / discharge control of the control unit 12.

[0051] Furthermore, the auxiliary power supply unit 13 adopts a dual AC / DC power supply redundancy scheme to provide a stable 24V DC power supply for low-voltage components such as the control unit 12, DC contactor coil, and detection unit. It also supports autonomous startup when the system has no external power supply. The specific structure is as follows:

[0052] The AC / DC dual power supply branch includes a DC power supply branch and an AC power supply branch. The input terminal of the DC power supply branch is connected to the low-voltage DC bus of the battery pack 100, and a first branch circuit breaker is connected in series. The first branch circuit breaker is a DC miniature circuit breaker QF2 with shunt trip. The output terminal is connected to the power supply terminal of the control unit 12 in sequence through a DC / DC converter and a dual common cathode anti-reverse diode D1, so as to convert the bus voltage into a 24V DC voltage and transmit it to the power input terminal of each low-voltage component. The shunt trip terminal of the DC miniature circuit breaker QF2 is electrically connected to the MCB control output terminal of the control unit 12, and the control unit 12 controls the on / off state.

[0053] The input terminal of the AC power supply branch is connected to an external AC power grid (such as 220V mains power), and a second branch circuit breaker is connected in series. The second branch circuit breaker is an AC miniature circuit breaker QF3. Its output terminal is connected to the power supply terminal of the control unit 12 through an AC / DC converter and a dual common cathode reverse protection diode D1, and is connected in parallel with the output terminal of the DC power supply branch. The AC is converted into 24V DC by the AC / DC converter, which together power the low-voltage components. The coil terminal of the AC miniature circuit breaker QF3 is electrically connected to the MCB control output terminal of the control unit 12, and is controlled by the control unit 12 to open and close.

[0054] When the system is running normally, the control unit 12 dynamically switches between the two power supply states (such as voltage and fault signals) to ensure stable power supply. In the event of an external AC power outage or the system's first startup (i.e., black start), the DC miniature circuit breaker QF2 is closed, and the DC power supply branch draws power from the battery pack 100. After conversion by the DC / DC converter, the power is supplied to the control unit 12, enabling the system to start autonomously without relying on an external AC power source.

[0055] Optionally, the control unit 12 is a battery management system main control unit (BCU) with a built-in self-test module. The control unit 12 integrates a signal acquisition terminal, a control output terminal, a communication interface, and a self-test module. Its signal acquisition terminal is connected to the current acquisition device (HET), the insulation status detection unit 14, the operation status monitoring unit 15, and the auxiliary power supply unit 13, respectively, to acquire the current signal from the current acquisition device (HET), the insulation resistance signal from the insulation detection unit, the arc signal from the operation monitoring unit, and the voltage signal from the auxiliary power supply unit 13, thereby realizing multi-dimensional status perception.

[0056] The control output terminal of the control unit 12 controls the opening and closing of DC contactors KM1, KM2, KM3, DC molded case circuit breaker QF1, DC miniature circuit breaker QF2 and AC miniature circuit breaker QF3 respectively, and outputs a DC 24V control signal.

[0057] Specifically, the communication interface is provided with two interfaces, Communication 1 and Communication 2, which can exchange data with the 200 PCS energy storage converter and the background monitoring system, such as charging and discharging commands and fault signals.

[0058] The signal input terminal of the self-test module is electrically connected to the output terminal of the auxiliary power supply unit 13. It is used to collect status parameters such as the voltage and current of the energy storage system, the status of the current collector, and the voltage of the contactor coil after the auxiliary power supply unit 13 is started, and generate a self-test signal. The self-test signal is transmitted to the signal processing terminal of the control unit 12.

[0059] After receiving a self-test pass signal transmitted by the self-test module, the control unit 12 outputs a start signal to the insulation status detection unit 14; after receiving a self-test fail signal, it outputs a hold signal to the auxiliary power supply unit 13 and outputs a fault signal to the external communication interface.

[0060] After the control system enters the charging and discharging preparation state, the control unit 12 first outputs a closing signal to the pre-charge switch. After the pre-charge time reaches the preset value, it outputs a disconnect signal to the pre-charge switch and a closing signal to the DC contactor of the main circuit switch unit 111.

[0061] Furthermore, in this embodiment, the insulation status detection unit 14 is an insulation detection module JY. The detection terminals of the insulation detection module JY are connected to the positive busbar B+ and the negative busbar B- of the battery pack 100 via wires, respectively, and the signal output terminal is connected to the insulation detection signal input terminal of the control unit 12 via a communication line. After the control unit 12 passes the self-test, it outputs a start signal to the insulation detection module. The insulation detection module JY collects the insulation resistance values ​​of the positive and negative terminals of the battery pack 100 to ground using the balanced bridge method and transmits the insulation resistance values ​​to the control unit 12.

[0062] If the insulation resistance value is greater than or equal to the product safety threshold, the insulation is deemed qualified, and the control unit 12 shuts down the insulation detection module JY and enters the charging and discharging preparation state; if the insulation resistance value is less than the product safety threshold, the control unit 12 outputs a fault signal to the external communication interface to prevent the system from starting.

[0063] Furthermore, the operation status monitoring unit 15 is an arc monitoring module (AFCI), used to monitor abnormal arcs in the DC main circuit during the operation of the energy storage system, such as arcing caused by loose lines or high-temperature sparks caused by poor contacts. The arc monitoring module (AFCI) has a built-in EEPROM memory that can store abnormal event records for several months, including arc occurrence time, location, temperature peak, and current waveform segments, with a storage capacity of ≥1000 records. It supports data reading through the RS485 interface of the control unit 12, facilitating maintenance personnel to trace the cause of faults.

[0064] Specifically, the monitoring end of the arc monitoring module AFCI is a ring current sensor, which is sleeved on the positive and negative busbars between the DC contactors KM1 and KM2 and the DC molded case circuit breaker QF1 in the DC main circuit, and is used to collect abnormal arc signals in the DC main circuit; the signal output end of the arc monitoring module AFCI is connected to the arc detection signal input end of the control unit 12 through a communication line, and transmits the abnormal arc signal to the control unit 12.

[0065] When the system enters the charging and discharging state, the control unit 12 automatically activates the arc monitoring module AFCI. The arc monitoring module AFCI identifies fault types such as series arc and parallel arc by monitoring the high-frequency pulse characteristics of abnormal arcs in the main circuit current, and transmits the abnormal arc signal to the control unit 12. After receiving the abnormal signal, the control unit 12 immediately triggers the fault protection logic: first disconnects the DC molded case circuit breaker QF1, and then disconnects the DC contactors KM1 and KM2 to prevent the arc from igniting the insulation layer of the line and causing a fire.

[0066] The system workflow described in this embodiment is divided into three stages: startup preparation, charging and discharging operation, and fault protection. The specific steps are as follows:

[0067] First, activate the system: close the QF2 of the auxiliary power supply unit 13 or the AC miniature circuit breaker QF3. The auxiliary power supply unit 13 outputs 24V DC power after conversion by a DC / DC converter or an AC / DC converter, which powers the control unit 12 and each detection module, thus activating the system.

[0068] The control unit 12 activates the built-in self-test module, performs a self-test operation, collects parameters such as the status of the auxiliary power supply unit 13, the cell voltage and temperature of the battery pack 100, the status of the current collector HET, and the status of the contactor, and generates a self-test signal.

[0069] If the self-test fails, the control unit 12 outputs a hold signal to the auxiliary power supply unit 13 (maintaining 24V power supply) and simultaneously sends a self-test fault signal to the background monitoring system via the communication interface, locking the system and prohibiting startup. If the self-test passes, the control unit 12 outputs a start signal to the insulation detection module to start insulation detection. The insulation detection module JY collects the insulation resistance values ​​of the positive and negative terminals of the battery pack 100 to ground and transmits them to the control unit 12. If the insulation fails, the control unit 12 outputs an insulation fault signal, prohibiting entry into the charging and discharging state. If the insulation passes, the control unit 12 shuts down the insulation detection module JY, and the system enters the charging and discharging preparation state.

[0070] Subsequently, the system enters the charging and discharging operation phase. The control unit 12 controls the DC contactor KM1 to be in the open state, and the high voltage current flows out from the positive terminal B+ of the battery pack 100, through the DC molded case circuit breaker QF1, DC contactor KM3, pre-charging resistor R, DC contactor KM2, and current collector HET back to the negative terminal B- of the battery pack 100, pre-charging the circuit capacitor on the side of the energy storage converter 200.

[0071] The control unit 12 acquires the voltages of the P+ and P- terminals at the back end of the DC main circuit through the voltage acquisition module, and calculates the difference between them and the voltage on the front end of the energy storage converter 200. When the voltage difference is ≤4%, the pre-charging process is considered complete. After the pre-charging is completed, the control unit 12 first outputs a closing control signal to the DC contactor KM1 of the main circuit switch unit 111, and at the same time outputs a disconnection control signal to the DC contactor KM3 of the pre-charging unit 113 to cut off the pre-charging circuit. At this time, the conduction path of the DC main circuit is: battery pack 100 positive terminal B+ → DC molded case circuit breaker QF1 of the main circuit protection unit 112 → DC contactor KM1 of the main circuit switch unit 111 → energy storage converter 200 → DC contactor KM2 of the main circuit switch unit 111 → current acquisition unit HET → battery pack 100 negative terminal B-, and the system officially switches to the charging and discharging operation state.

[0072] At the same time, the control unit 12 starts the operation status monitoring module AFCI, which collects the arc signal of the DC main circuit in real time, the current collector HET collects the current signal in real time, and the control unit 12 monitors the voltage of the battery pack 100 in real time. All data are synchronously transmitted to the background monitoring system.

[0073] During system operation, if the control unit 12 detects the following fault signals, it will immediately trigger the protection logic:

[0074] When the control unit 12 receives an abnormal arc signal from the operating status monitoring module AFCI, an overload signal or short-circuit current signal from the current acquisition unit HET, or an overcharge voltage signal or over-discharge voltage signal transmitted from the voltage acquisition terminal, the control unit 12 outputs a disconnect signal to the shunt trip terminal of the DC molded case circuit breaker QF1 to control the DC molded case circuit breaker QF1 to trip and cut off the high-voltage current in the DC main circuit. After the DC molded case circuit breaker QF1 trips, the control unit 12 outputs a disconnect signal to the DC contactors KM1 and KM2 to completely disconnect the main circuit switch. The control unit 12 outputs a fault protection signal to the auxiliary power supply unit 13 to maintain low-voltage power supply, and simultaneously uploads the fault type, such as arc fault or short-circuit fault, through the communication interface. The system stops operating and waits for fault investigation.

[0075] If the control unit 12 fails to properly control the DC molded case circuit breaker QF1 to disconnect, the passive protection function of the DC molded case circuit breaker QF1 can automatically disconnect when overloaded or when the short-circuit current exceeds the threshold, thus preventing the fault from escalating.

[0076] In addition, such as Figure 4 As shown, this embodiment also provides a high-voltage box for an outdoor energy storage cabinet, which includes a box body 1 and the control system described above, with the control system located inside the box body 1.

[0077] Furthermore, the enclosure 1 is made of SGCC material with a plate thickness of not less than 1.2mm, a protection level of IP20, and must comply with RoHS environmental protection standards; the surface of the enclosure 1 is treated with powder coating, and the coating thickness is controlled within the range of 60μm-240μm; for this powder-coated sheet metal part, its salt spray test endurance time must be not less than 500 hours.

[0078] The front of the enclosure 1 is equipped with air inlets with a diameter of 3mm and a center-to-center spacing of 5mm; the rear integrates an axial cooling fan with a temperature sensor inside. The temperature control logic is as follows: when the internal temperature is greater than or equal to 45℃, the control unit 12 automatically starts the fan, and shuts it off when the temperature is below 30℃ to reduce the impact of component heat generation on other modules.

[0079] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A control system suitable for outdoor energy storage cabinet high-voltage boxes, characterized in that, The application relates to a high-voltage power distribution unit, a control unit, an auxiliary power supply unit, an insulation state detection unit and an operation state monitoring unit. The high-voltage power distribution unit comprises a main loop switch unit, a main loop protection unit and a pre-charging unit, the main loop protection unit and the main loop switch unit are connected in series in a direct-current main loop between a battery pack and an energy storage converter in an energy storage system, the main loop switch unit comprises a plurality of direct-current contactors, the main loop protection unit is a direct-current molded case circuit breaker, the direct-current molded case circuit breaker and the plurality of direct-current contactors are connected in series in the direct-current main loop, the pre-charging unit comprises a pre-charging resistor and a pre-charging switch, and the pre-charging switch and the pre-charging resistor are connected in series and then connected in parallel at two ends of the main loop switch unit. The auxiliary power supply unit comprises an AC / DC dual-circuit power supply branch, the AC / DC dual-circuit power supply branch comprises a direct-current power supply branch and an alternating-current power supply branch, an input end of the direct-current power supply branch is connected to a direct-current bus of the battery pack, and an output end of the direct-current power supply branch is connected to a power input end of the control unit; an input end of the alternating-current power supply branch is connected to an external alternating-current power grid, an output end of the alternating-current power supply branch is connected in parallel with an output end of the direct-current power supply branch, and the output end of the alternating-current power supply branch is connected to the power input end of the control unit through an AC / DC converter and a dual-circuit common cathode anti-reverse diode; a first branch circuit breaker is connected in series in the direct-current power supply branch, an output end of the first branch circuit breaker is connected to the power end of the control unit through a DC / DC converter and the dual-circuit common cathode anti-reverse diode, so as to convert a bus voltage into a 24V direct-current voltage and transmit the 24V direct-current voltage to a power input end of each low-voltage component; a second branch circuit breaker is connected in series in the alternating-current power supply branch, an output end of the second branch circuit breaker is connected to the power end of the control unit through an AC / DC converter and the dual-circuit common cathode anti-reverse diode, and the output end of the second branch circuit breaker is connected in parallel with the output end of the direct-current power supply branch; control ends of the first branch circuit breaker and the second branch circuit breaker are respectively connected to a control output end of the control unit. When the system is normally operated, the control unit dynamically switches according to power supply states of the direct-current power supply branch and the alternating-current power supply branch; in the case of external alternating-current power-off and system first start, the first branch circuit breaker is closed, the direct-current power supply branch takes power from the battery pack, and the control unit is powered after conversion through the DC / DC converter. The insulation state detection unit is an insulation detection module, a detection end of the insulation detection module is connected to positive and negative bus lines of the battery pack through wires, a signal output end of the insulation detection module is connected to the control unit, the insulation detection module is used for collecting an insulation resistance value of the battery pack and transmitting the insulation resistance value as an insulation state signal to the control unit. The operation state monitoring unit is an arc monitoring module, a monitoring end of the arc monitoring module is sleeved on a wire of the direct-current main loop, the arc monitoring module is used for collecting an abnormal arc signal in the direct-current main loop and transmitting the abnormal arc signal as an abnormal state signal to the control unit. ​ The control output end of the control unit is electrically connected with the branch control end of the main loop switch unit, the main loop protection unit, the auxiliary power supply unit and the control end of the pre-charge switch, for controlling the on-off of the main loop switch unit and the main loop protection unit and the switching of the AC / DC dual power supply branch according to the insulation state signal and the abnormal state signal; The control unit is internally provided with a self-checking module, the signal input end of the self-checking module is electrically connected with the output end of the auxiliary power supply unit, and the insulation state detection unit is used for collecting state parameters of the energy storage system and generating a self-checking signal after the auxiliary power supply unit is started, which is transmitted to the signal processing end of the control unit; The control output end of the control unit is electrically connected with the branch control end of the main loop switch unit, the main loop protection unit, the auxiliary power supply unit and the control end of the pre-charge switch, for outputting a starting signal to the insulation state detection unit after receiving the self-checking qualified signal transmitted by the self-checking module, collecting the insulation resistance values of the positive and negative electrodes of the battery pack to the ground before the energy storage system is started, and transmitting the insulation resistance values to the control unit, if the insulation resistance values are greater than or equal to a preset safety threshold, it is determined that the insulation is qualified, the control unit closes the insulation state detection unit and enters a charging and discharging preparation state; after entering the charging and discharging preparation state, the control unit first outputs a closing signal to the pre-charge switch, waits for the pre-charge time to reach a preset value, outputs an opening signal to the pre-charge switch, and outputs a closing signal to the DC contactor of the main loop switch unit; if the insulation resistance value is less than the preset safety threshold, the control unit outputs a fault signal to the external communication interface to prohibit the system from starting; After receiving the self-checking unqualified signal, a holding signal is output to the auxiliary power supply unit, and a fault signal is output to the external communication interface to prohibit the system from starting; When the control unit receives the abnormal state signal of the running state monitoring unit, or receives a system voltage alarm signal, a system current alarm signal or a short-circuit current signal, it first outputs an opening signal to the DC molded case circuit breaker of the main loop protection unit to cut off the DC main loop high-voltage current; after the DC molded case circuit breaker is disconnected, an opening signal is output to control the DC contactor of the main loop switch unit; If the control unit fails to control the DC molded case circuit breaker to be disconnected, the DC molded case circuit breaker is automatically disconnected when the overload or short-circuit current exceeds the threshold.

2. A high voltage tank of an outdoor energy storage cabinet, characterized in that, The control system as claimed in claim 1 is placed in the box body. The control system as claimed in claim 1 is placed in the box body.

Images