Rapid power failure detection energy storage system and protection method thereof

Abstract

The invention discloses a rapid power failure detection energy storage system and a protection method thereof. The system comprises an AC-DC module, a power failure detection module, an energy storage battery cluster, a PCS, a BMS, an EMS and an onboard super capacitor module. The power failure detection module detects AC-DC output direct current voltage through a comparator, and comprehensive and rapid power failure detection is achieved. The onboard super capacitor module supplies power after power failure, and replaces the UPS to reduce the cost; according to the protection method, scheduling is triggered through power failure detection, so that the contactor is turned off at low power, damage is avoided, fault information is saved, and system safety and reliability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery energy storage, in particular to a rapid power-off detection energy storage system and a protection method thereof. BACKGROUND

[0002] The battery energy storage system is usually composed of a battery cluster, an energy storage converter PCS, a BMS (battery management system) and an EMS (energy management system), etc. Among them, the energy storage converter PCS realizes the charging and discharging of the battery cluster; the BMS detects the voltage and current of each battery cell in the battery cluster; and the EMS is responsible for energy scheduling and uploading operation information to the cloud platform.

[0003] In the charging and discharging process of the energy storage system, if there is no power-off detection and protection function, when the power is suddenly cut off, the data cannot be saved and uploaded, which is not conducive to subsequent cause analysis. At the same time, sudden power-off may cause the contactor in the energy storage converter to arc, the impact current to be too high and the equipment to be damaged, causing irreparable loss to the entire energy storage system.

[0004] At present, the existing energy storage technology is mostly used in networking systems. For the control power-off detection technology, the sensor is directly detected on the alternating current end, which is high in cost and cannot detect other types of power-off faults except for the alternating current end. In addition, when the power-off protection function is added to most energy storage systems, an UPS (uninterruptible power supply) is usually added as an auxiliary power supply to provide some protection when the power is cut off. However, this solution has high cost and the UPS is too large in size, which is not conducive to installation.

[0005] Therefore, there is an urgent need for an energy storage system and a protection method thereof which can quickly and comprehensively detect power-off, are low in cost and easy to install, so as to solve the above problems. SUMMARY

[0006] In view of the limited detection range, high cost, data loss after power-off and equipment damage of the existing energy storage system power-off detection technology, the present application provides a rapid power-off detection energy storage system and a protection method thereof.

[0007] To achieve the above purpose, the following technical means are adopted in the present application: A rapid power-off detection energy storage system, comprising an AC-DC module, a power-off detection module, an energy storage battery cluster, a PCS, a BMS, an EMS and an on-board super capacitor module; The AC-DC module is used to provide auxiliary control power for the 3S in the PCS, EMS and BMS, so as to ensure the normal operation of the energy storage system; The power-off detection module is used to detect the direct current voltage of the control power output by the AC-DC module; The energy storage battery cluster is composed of a plurality of single batteries in series or parallel mode, serving as an energy storage carrier of the energy storage system to provide DC power output or receive external input DC power for storage. The PCS is used to convert DC power of the energy storage battery cluster into AC power for use of the user end power grid, and meanwhile, convert AC power of the user end into DC power for charging the energy storage battery cluster. The BMS is used to detect voltage, current and temperature information of each battery in the energy storage battery cluster, estimate SOC, and upload the information to the EMS. The EMS is used to be responsible for global energy scheduling and optimization, receive power grid instructions and battery state information provided by the BMS, predict energy demand and supply through intelligent algorithms, and issue charge and discharge instructions to the PCS. The on-board super capacitor module is used to distribute power supply for the PCS, the EMS and the BMS.

[0008] As a preferred, the power failure detection module comprises a comparator U1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a MOS tube Q1 and a MOS tube Q3; one end of the resistor R1 is connected with a 3 forward end of the comparator U1, the other end of the resistor R1 is connected with an output end of the AC-DC module, a 1 reverse end of the comparator U1 is connected with a +3V3 DC voltage power source through the resistor R2, a 2 end of the comparator U1 is grounded, a 4 end of the comparator U1 is connected with a gate of the MOS tube Q3 through the resistor R3, the 4 end of the comparator U1 is connected with MCU_IO1, a 5 end of the comparator U1 is connected with a power voltage, a source of the MOS tube Q3 is connected with a gate of the MOS tube Q1 through the resistor R4, a drain of the MOS tube Q3 is grounded, a source of the MOS tube Q1 is connected with the power voltage, and a drain of the MOS tube Q1 is connected with the output end of the AC-DC module.

[0009] As a preferred, the PCS is connected with the energy storage battery cluster through a high-voltage box.

[0010] As preferred, the on-board super capacitor module comprises a boost chip U2, a super capacitor C1, a diode D1, a diode D2, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, an inductor L3, a MOS tube Q2, and a MOS tube Q4; the No. 1 terminal of the boost chip U2 is connected with the anode terminal of the diode D1 and one end of the inductor L3, the No. 3 terminal of the boost chip U2 is connected with the resistor R7 and one end of the resistor R8, the No. 4 and No. 5 terminals of the boost chip U2 are connected with the other end of the inductor L3, the No. 6 terminal of the boost chip U2 is connected with one end of the resistor R9, the other end of the inductor L3 is connected with the anode terminal of the super capacitor C1 and one end of the resistor R10, the No. 2 terminal of the boost chip U2, the other end of the resistor R8, the other end of the resistor R9, and the cathode terminal of the super capacitor C1 are grounded, the other end of the resistor R10 is connected with the cathode terminal of the diode D2, the anode terminal of the diode D2 is connected with the output terminal of the AC-DC module, the cathode terminal of the D1 and the other end of the resistor R7 are connected with the source of the MOS tube Q2, the drain of the MOS tube Q2 is connected with a power supply voltage, the gate of the MOS tube Q2 is connected with the source of the MOS tube Q4 through the resistor R5, the drain of the MOS tube Q4 is grounded, and the gate of the MOS tube Q4 is connected with MCU_IO2 through the resistor R6. The inductor L3, the diode D1, the resistor R7, the resistor R8, the resistor R9, and the boost chip U2 form a boost circuit.

[0011] A protection method for a fast power-off detection energy storage system, comprising the following steps: S1: The energy storage system uploads system data transmitted by the BMS and the PCS to the cloud platform server through the EMS, and the cloud platform server receives the data and stores it to the local database; S2: When the energy storage system starts to power off, the power-off detection module detects the change of the IO signal, the EMS schedules shutdown, prevents the contactor inside the PCS from being damaged due to the sudden power-off of high power, and starts to save information to the cloud platform; S3: The on-board super capacitor module continues to provide control power for the energy storage system, ensuring that the EMS has enough time to save data; S4: When the energy storage system is powered off or other faults occur, the EMS schedules to shut down the charging and discharging of the system, and finally shuts down the contactor, ensuring that the contactor is shut down at zero power or small power, avoiding overvoltage and arc of the equipment; S5: After the EMS receives various fault information, it uploads the information to the cloud and saves it, and at the same time controls the PCS to change from the current charging and discharging state to the stop charging and discharging state.

[0012] As preferably, in step S2, the power-off detection module compares the AC-DC module output voltage with +3V3 voltage through the comparator U1, outputs the corresponding level signal, and makes the MCU detect the IO signal change.

[0013] As preferably, in step S3, the on-board super capacitor module charges the super capacitor C1 when the AC-DC module normally supplies power, and supplies power to the system through the boost circuit, MOS tube Q2 and MOS tube Q4 after power-off.

[0014] As preferably, in step S4, after the EMS schedules to turn off the charging and discharging, the PCS or the power-off detection module sends a stop working signal to the BMS, and the BMS controls the high-voltage box main positive contactor to be disconnected.

[0015] The application has the following beneficial effects: 1. The application completes the DC detection of the AC-DC module through the comparator in the power-off detection device, which not only solves the problem of detecting only AC power-off, but also detects power-off caused by other faults, and realizes rapid and comprehensive power-off detection.

[0016] 2. The application can continue to supply power to the energy storage system through the on-board super capacitor module after the AC-DC module control power of the energy storage system is off, solves the problem that the information cannot be saved after the control power of the energy storage system is rapidly off, replaces the UPS power supply, reduces the cost of the whole system, and has small size and is convenient to install.

[0017] 3. The protection method of the application triggers a series of operations through the power-off detection, makes the contactor be turned off at zero power or small power, avoids the damage of the equipment caused by overvoltage and arc, improves the safety and reliability of the system, and the saved fault information is convenient for tracking problems and analyzing reasons in the later period. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the system block diagram of the application; Figure 2 is the method flow chart of the application; Figure 3 is the circuit diagram of the power-off detection module of the application; Figure 4 is the circuit diagram of the on-board super capacitor module of the application; Figure 5 is the connection schematic diagram of the PCS and the energy storage battery cluster of the application; Among them, the reference signs are: AC-DC module 100, power-off detection module 110, energy storage battery cluster 120, PCS 130, BMS 140, EMS 150, on-board super capacitor module 160, high-voltage box 170. DETAILED DESCRIPTION

[0019] The technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0020] As shown in the drawings, a fast power-off detection energy storage system includes an AC-DC module 100, a power-off detection module 110, an energy storage battery cluster 120, a PCS 130, a BMS 140, an EMS 150, and an on-board super capacitor module. Figures 1-5 The AC-DC module 100 mainly provides auxiliary control power for the 3S in the EMS 150, the BMS 140, and the PCS 130 to ensure normal operation of the energy storage system.

[0021] The AC-DC module 100 mainly provides auxiliary control power for the 3S in the EMS 150, the BMS 140, and the PCS 130 to ensure normal operation of the energy storage system.

[0022] The power-off detection module 110 is mainly used for detecting the DC voltage of the output control power of the AC-DC module 100, and includes a comparator U1, resistors R1, R2, R3, R4, MOS tubes Q1 and Q3. One end of the resistor R1 is connected to the positive terminal 3 of the comparator U1, the other end of the resistor R1 is connected to the output end of the AC-DC module 100, the negative terminal 1 of the comparator U1 is connected to a +3V3 DC voltage power supply through the resistor R2, the 2nd terminal of the comparator U1 is grounded, the 4th terminal of the comparator U1 is connected to the gate of the MOS tube Q3 through the resistor R3, the 4th terminal of the comparator U1 is connected to MCU_IO1, the 5th terminal of the comparator U1 is connected to the power supply voltage, the source of the MOS tube Q3 is connected to the gate of the MOS tube Q1 through the resistor R4, the drain of the MOS tube Q3 is grounded, the source of the MOS tube Q1 is connected to the power supply voltage, and the drain of the MOS tube Q1 is connected to the output end of the AC-DC module 100.

[0023] In the invention, the direct current control electricity (ACDC_IN) output by the AC-DC module 100 is directly connected to one end of the resistor R1, the other end of the resistor R1 is connected to the positive end of the comparator U1, and the negative end of the comparator is connected to the +3V3 power supply of the MCU of the system. The voltages at the positive and negative ends of the comparator U1 are compared. When the energy storage system is not powered off, the voltage at the positive end is greater than that at the negative end, the comparator outputs a high level, and at this time, the MCU detects that the voltage is in a high level state and does not perform power-off processing. At the same time, the MOS tube Q3 is turned on, and since the MOS tube Q3 is connected to one end of the resistor R4 and the other end of the resistor R4 is connected to the gate of the MOS tube Q1, the MOS tube Q1 is also turned on, and at this time, the input of ACDC_IN supplies power to VCC. When the energy storage system is powered off, ACDC_IN has no power, the voltage at the negative end of the comparator U1 is greater than that at the positive end, the 4-pin output of the comparator U1 is low, and after the MCU detects the low level (at this time, the power is supplied by the on-board super capacitor module), the EMS 150 starts to schedule charging and discharging, and saves fault information.

[0024] The energy storage battery cluster 120 is composed of a plurality of single batteries in series or parallel mode, serving as an energy storage carrier of the energy storage system to provide direct current power output or receive external input of direct current power for storage.

[0025] The main function of the PCS 130 is to convert the direct current of the energy storage battery cluster 120 into alternating current for use by the user end power grid, and also to convert the alternating current of the user end into direct current for charging the battery.

[0026] The BMS 140 is a device for detecting the voltage, current, temperature and other information of each battery in the energy storage system, and is responsible for estimating the SOC (battery remaining capacity) and uploading these information to the EMS 150, and then uploading to the cloud by the EMS 150, to provide accurate power information for the user.

[0027] The EMS 150 is mainly responsible for global energy scheduling and optimization. It receives the instructions of the power grid and the battery state information provided by the BMS 140, predicts the energy demand and supply through intelligent algorithms, and issues charging and discharging instructions to the PCS 130 to realize the functions of peak load shifting, frequency and phase modulation of the energy storage system.

[0028] The on-board super capacitor module is mainly used for distributed power supply of the PCS 130, the EMS 150 and the BMS 140, that is, the on-board super capacitor module is connected to the PCS 130, the EMS 150 and the BMS 140, so as to continue to supply power when the AC-DC module 100 suddenly loses power, prevent data loss caused by the fact that the EMS 150 cannot be sensed when the power is suddenly lost, and prevent the arc damage of the contactor caused by the sudden loss of power of the PCS 130. The on-board super capacitor module comprises a boost chip U2, a super capacitor C1, a diode D1, a diode D2, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, an inductor L3, a MOS tube Q2 and a MOS tube Q4.

[0029] The 1st end of the boost chip U2 is connected to the anode end of the diode D1 and one end of the inductor L3, the 3rd end of the boost chip U2 is connected to one end of the resistor R7 and the resistor R8, the 4th and 5th ends of the boost chip U2 are connected to the other end of the inductor L3, the 6th end of the boost chip U2 is connected to one end of the resistor R9, the other end of the inductor L3 is connected to the anode end of the super capacitor C1 and one end of the resistor R10, the 2nd end of the boost chip U2, the other end of the resistor R8, the other end of the resistor R9 and the cathode end of the super capacitor C1 are grounded, the other end of the resistor R10 is connected to the cathode end of the diode D2, the anode end of the diode D2 is connected to the output end of the AC-DC module 100, the cathode end of the diode D1 and the other end of the resistor R7 are connected to the source of the MOS tube Q2, the drain of the MOS tube Q2 is connected to the power supply voltage, the gate of the MOS tube Q2 is connected to the source of the MOS tube Q4 through the resistor R5, the drain of the MOS tube Q4 is grounded, and the gate of the MOS tube Q4 is connected to MCU_IO2 through the resistor R6.

[0030] The inductor L3, the diode D1, the resistor R7, the resistor R8, the resistor R9 and the boost chip U2 form a stable boost circuit to provide a stable voltage. The MOS tube Q2, the MOS tube Q4, the resistor R5 and the resistor R6 form a part, so that the on-board super capacitor module can continue to supply power to the board after the input loses power. In the present application, when the ACDC_IN normally supplies power, the anode of the diode D2 is connected, the cathode of the diode D2 is connected to one end of the resistor R10, the other end of the resistor R10 is connected to the anode of the super capacitor C1, and the cathode end of the super capacitor C1 is connected to GND, mainly charging the super capacitor when normally supplying power. The ACDC_IN passes through the boost circuit, so that the super capacitor can have a stable output voltage to supply VCC at low voltage.

[0031] When the system loses power, MOSFET Q4 is on with its gate at a low level, while MOSFET Q2 is on, allowing the boost circuit's regulated voltage to continue supplying power to VCC through MOSFET Q2. When the EMS150 receives a system fault or power-down message, it stops charging and discharging and saves the fault information, uploading it to the cloud platform. Finally, the MCU changes the MCU_IO2 signal from high to low, turning off MOSFET Q4 and Q2, preventing the boost voltage from continuing to supply power. At this point, the EMS150 has uploaded the fault information to the cloud platform, and the entire system loses power.

[0032] PCS130 is connected to the battery cluster via high-voltage box 170. When the power failure detection module 110 or the energy storage converter stops working, it will send a stop working signal to BMS140. After BMS140 detects the signal, it controls the main positive contactor in the high-voltage box to disconnect. At this time, the contactor will not be damaged because there is no high power passing through it.

[0033] This invention also provides a protection method for a fast power failure detection energy storage system, specifically including the following steps: S1: The energy storage system uploads system data transmitted from BMS140 and PCS130 to the cloud platform server via EMS150. The cloud platform server receives the data and stores it in the local database for subsequent querying and analysis.

[0034] S2: When the energy storage system begins to lose power, the comparator U1 in the power failure detection module 110 compares the output voltage of the AC-DC module 100 with the +3V3 voltage, and outputs a corresponding level signal, causing the MCU to detect the change in the IO signal. After receiving the signal, the EMS150 starts scheduling a shutdown to prevent arcing damage to the contactor in the PCS130 caused by a sudden high-power power failure, and begins saving information to the cloud platform.

[0035] S3: When the AC-DC module 100 is supplying power normally, the onboard supercapacitor module charges the supercapacitor C1. After power failure, the boost circuit, MOSFET Q2, and MOSFET Q4 control the continued supply of control power to the energy storage system. This device not only provides power when the energy storage system fails, but also provides power during other system failures. In this invention, the main consideration is the situation after power failure, ensuring that the EMS150 has sufficient time to save data.

[0036] S4: When the control power of the energy storage system fails or other faults occur, the EMS150 will shut down the charging and discharging of the system. Afterwards, the PCS130 or the power failure detection module 110 will send a stop working signal to the BMS140. The BMS140 will control the main positive contactor of the high-voltage box to disconnect, ensuring that the contactor is turned off at zero power or low power to avoid over-charging and arcing.

[0037] S5: When EMS 150 receives various fault information, it starts uploading information to the cloud and saving, while controlling PCS 130 to change from the current charging and discharging state to the state of stopping charging and discharging. The saved information facilitates later tracking of problems and analysis of causes. Embodiment 1

[0038] The fast power-off detection energy storage system and its protection method of the application are applied in an energy storage system of a certain data center. The data center is equipped with an energy storage system with a rated capacity of 500 kWh, in which the rated power of PCS 130 is 200 kW, and the energy storage battery cluster 120 is composed of lithium iron phosphate batteries, which contains 100 battery modules, each with a voltage of 51.2 V and a capacity of 100 Ah.

[0039] In the normal operation process, the energy storage system adjusts charging and discharging according to the power demand of the data center. When the power fluctuates, causing the control voltage output by the AC-DC module 100 to change, the power-off detection module 110 quickly comes into play. The comparator U1 in the power-off detection module 110 compares the output voltage of the AC-DC module 100 with the +3V3 voltage in real time. For example, when the output voltage of the AC-DC module 100 drops to a certain extent due to power fluctuation, the comparator U1 outputs a low-level signal, and the MCU detects the signal and immediately notifies the EMS 150.

[0040] EMS 150 responds quickly, on the one hand, to schedule PCS 130 to stop the current charging and discharging operation to prevent the contactor in the energy storage inverter from being damaged by arc due to sudden power-off of high power; on the other hand, to start collecting and organizing the running data of the current energy storage system, including the voltage, current, temperature, SOC, etc. of the battery cluster, as well as the working state information of the PCS 130, etc.

[0041] At this time, the on-board super capacitor module 160 starts to play a power supply role. When the AC-DC module 100 is normally powered, the super capacitor C1 in the on-board super capacitor module 160 is charged through the diode D2 and the resistor R10. When power-off is detected, the MOS tube Q4 is turned on, and then the MOS tube Q2 is turned on, the boost circuit (composed of inductor L3, diode D1, resistor R7, resistor R8, resistor R9, and boost chip U2) boosts the electrical energy stored in the super capacitor C1, and supplies power to VCC through the MOS tube Q2, to continue to provide control electricity for EMS 150, BMS 140 and 3S in PCS 130, ensuring that EMS 150 has enough time to upload the organized fault information to the cloud platform server for saving.

[0042] After completing data saving and uploading, the MCU controls the MCU_IO2 signal port to change from high level to low level, the MOS tube Q4 is turned off, the MOS tube Q2 is also turned off, the on-board super capacitor module 160 stops power supply, and the whole system enters a safe shutdown state. Through actual test, from detecting the power failure signal by the power failure detection module 110 to completing data saving and uploading by the EMS 150, the whole process takes a short time, effectively avoids data loss and equipment damage, and guarantees stable operation of the data center energy storage system. Embodiment 2

[0043] A certain distributed photovoltaic power station uses the energy storage system of the application to store excess power and supplement power for the power grid during power consumption peaks. In the energy storage system of the photovoltaic power station, the PCS 130 has a rated power of 150 kW, the energy storage battery cluster 120 uses ternary lithium batteries, 80 battery modules are connected in series, each module has a voltage of 48 V and a capacity of 120 Ah.

[0044] In daily operation, the energy storage system of the photovoltaic power station cooperates with the photovoltaic panel to store excess power generated by the photovoltaic panel into the energy storage battery cluster 120. When encountering severe weather such as heavy rain, which causes large voltage fluctuations of the power grid and further causes the AC-DC module 100 to output control power failure, the system of the application shows good protection performance.

[0045] The comparator U1 in the power failure detection module 110 detects abnormal output voltage of the AC-DC module 100, outputs a low level signal to the MCU, and the MCU transmits the signal to the EMS 150. The EMS 150 immediately starts a scheduling program, first sends a stop charging and discharging instruction to the PCS 130, at this time the PCS 130 is disconnected from the energy storage battery cluster 120 through the high-voltage box 170, and sends a stop working signal to the BMS 140. After receiving the signal, the BMS 140 controls the main positive contactor in the high-voltage box to be disconnected, so as to avoid damage of the contactor in the power-off state under high power.

[0046] At the same time, the on-board super capacitor module 160 starts to supply power to the system. Since the super capacitor C1 has been charged in normal work, after power failure, the voltage of the super capacitor C1 is quickly raised to the required voltage of the system, and the MOS tube Q2 continuously supplies power to the PCS 130, the EMS 150 and the BMS 140. The EMS 150 uses this time to sort and pack detailed operation data of the energy storage system at the power failure moment, such as real-time voltage, current and temperature of each battery module, and information such as power generation power of the photovoltaic panel and charging and discharging power of the energy storage system, and uploads them to the cloud platform.

[0047] After a series of operations such as data saving and uploading are completed, the system stops running gradually according to the preset program, and the energy storage system can quickly restore the normal working state after the voltage of the power grid recovers and stabilizes. It has been verified in practice that in many similar power-off scenarios, the energy storage system of the application can reliably detect power-off and implement protection measures, ensuring the data integrity and equipment safety of the energy storage system of the photovoltaic power station, and ensuring the stable operation of the photovoltaic power station and the reliability of the power supply. Example 3

[0048] A rapid power-off detection energy storage system of the application is installed in a certain electric vehicle charging station to provide additional power support for charging piles during peak hours and relieve the pressure on the power grid. The rated power of the PCS 130 in the energy storage system is 300kW, and the energy storage battery cluster 120 is composed of lithium titanate batteries, a total of 60 battery modules, each module voltage is 60V, and the capacity is 80Ah.

[0049] During the charging process of the electric vehicle, sudden changes in charging demand may cause fluctuations in the power grid current, affecting the stability of the control power output by the AC-DC module 100. When the output voltage of the AC-DC module 100 abnormally decreases, the power-off detection module 110 responds quickly. The comparator U1 outputs the corresponding level signal to the MCU according to the comparison result of the output voltage of the AC-DC module 100 and the +3V3 reference voltage. After the MCU detects the power-off signal, it immediately notifies the EMS 150.

[0050] The EMS 150 takes action quickly, on the one hand, controls the PCS 130 to stop supplying power to the charging pile to prevent damage to the contactor in the PCS 130 due to sudden changes in power; on the other hand, starts the on-board super capacitor module 160 to supply power to the system. The super capacitor C1 in the on-board super capacitor module 160 has stored enough power during normal power supply, and after power-off, the boost circuit boosts the power of the super capacitor C1, and then provides stable control power for the 3S in the EMS 150, BMS 140 and PCS 130 through the MOS tube Q2.

[0051] During the power supply period of the on-board super capacitor module 160, the EMS 150 collects and analyzes the operation data of the energy storage system, including the remaining power of the battery cluster, the charge and discharge history record, the working efficiency of the PCS 130 and other information, and uploads these data to the cloud platform. At the same time, the EMS 150 sends a fault notification to the charging pile management system to inform the user of the reason for the temporary interruption of the charging service.

[0052] When the power grid recovers stability, the EMS 150 controls the PCS 130 to restart, restores the power supply to the charging pile, and switches the operation state of the energy storage system back to the normal mode. Through actual operation test, the energy storage system of the application can quickly detect and effectively protect the system in response to power failure caused by power grid fluctuation in the charging station for many times, which guarantees the normal operation of the electric vehicle charging station and improves the charging experience of users.

[0053] The above examples are made by the application, but are not limited to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and all the embodiments do not need to be exhausted here, and the obvious changes or variations derived therefrom are still within the protection scope of the application.

Claims

1. A fast-battery-die detection energy storage system, comprising: The AC-DC module, the power failure detection module, the energy storage battery cluster, the PCS, the BMS, the EMS and the on-board super capacitor module are included. The AC-DC module is used for providing auxiliary control power for 3S in the PCS, the EMS and the BMS, and ensuring normal operation of the energy storage system. The power failure detection module is used for detecting the DC voltage of the control power output by the AC-DC module. The energy storage battery cluster is composed of a plurality of single batteries in series or parallel connection, and is used as an energy storage carrier of the energy storage system to provide DC power output or receive external input DC power for storage. The PCS is used for converting the DC power of the energy storage battery cluster into AC power for use of the user end power grid, and converting the AC power of the user end into DC power for charging the energy storage battery cluster. The BMS is used for detecting the voltage, current and temperature information of each battery in the energy storage battery cluster, estimating the SOC, and uploading the information to the EMS. The EMS is used for scheduling and optimizing the global energy, receiving the power grid instruction and the battery state information provided by the BMS, predicting the energy demand and supply through an intelligent algorithm, and issuing the charge and discharge instruction to the PCS. The on-board super capacitor module is used for distributing power supply for the PCS, the EMS and the BMS.

2. A fast power-down detection energy storage system according to claim 1, wherein, The power failure detection module includes a comparator U1, resistors R1, R2, R3, R4, MOS tubes Q1 and Q3, one end of the resistor R1 is connected with a positive terminal 3 of the comparator U1, the other end of the resistor R1 is connected with an output terminal of the AC-DC module, a negative terminal 1 of the comparator U1 is connected with a DC voltage power supply of +3V3 through the resistor R2, a terminal 2 of the comparator U1 is grounded, a terminal 4 of the comparator U1 is connected with a gate of the MOS tube Q3 through the resistor R3, the terminal 4 of the comparator U1 is connected with MCU_IO1, a terminal 5 of the comparator U1 is connected with a power voltage, a source of the MOS tube Q3 is connected with a gate of the MOS tube Q1 through the resistor R4, a drain of the MOS tube Q3 is grounded, a source of the MOS tube Q1 is connected with the power voltage, and a drain of the MOS tube Q1 is connected with the output terminal of the AC-DC module.

3. A fast power-down detection energy storage system according to claim 1, wherein, The PCS is connected with the energy storage battery cluster through a high-voltage box.

4. A fast power-down detection energy storage system according to claim 1, wherein, The on-board super capacitor module comprises a boost chip U2, a super capacitor C1, a diode D1, a diode D2, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, an inductor L3, a MOS tube Q2 and a MOS tube Q4; the No. 1 terminal of the boost chip U2 is connected with the anode terminal of the diode D1 and one end of the inductor L3, the No. 3 terminal of the boost chip U2 is connected with the resistor R7 and one end of the resistor R8, the No. 4 and No. 5 terminals of the boost chip U2 are connected with the other end of the inductor L3, the No. 6 terminal of the boost chip U2 is connected with one end of the resistor R9, the other end of the inductor L3 is connected with the anode terminal of the super capacitor C1 and one end of the resistor R10, the No. 2 terminal of the boost chip U2, the other end of the resistor R8, the other end of the resistor R9 and the cathode terminal of the super capacitor C1 are grounded, the other end of the resistor R10 is connected with the cathode terminal of the diode D2, the anode terminal of the diode D2 is connected with the output terminal of the AC-DC module, the cathode terminal of the D1 and the other end of the resistor R7 are connected with the source of the MOS tube Q2, the drain of the MOS tube Q2 is connected with a power supply voltage, the gate of the MOS tube Q2 is connected with the source of the MOS tube Q4 through the resistor R5, the drain of the MOS tube Q4 is grounded, and the gate of the MOS tube Q4 is connected with MCU_IO2 through the resistor R6. The inductor L3, the diode D1, the resistor R7, the resistor R8, the resistor R9 and the boost chip U2 form a boost circuit.

5. A method for protecting a fast-battery-detection energy storage system, applied to the system of any one of claims 1-4, characterized in that, The method comprises the following steps: S1: The energy storage system uploads the system data transmitted by the BMS and the PCS to the cloud platform server through the EMS, and the cloud platform server receives and stores the data to a local database; S2: When the energy storage system starts to power off, the power-off detection module detects the change of the IO signal, the EMS schedules shutdown to prevent the contactor in the PCS from being damaged due to the sudden power-off of the high power, and starts to save information to the cloud platform; S3: The on-board super capacitor module continues to provide control power for the energy storage system to ensure that the EMS has enough time to save data; S4: When the energy storage system is powered off or other faults occur, the EMS schedules to shut down the charging and discharging of the system, and finally shuts down the contactor, so as to ensure that the contactor is shut down at zero power or small power, thereby avoiding the overvoltage arc of the equipment; S5: After the EMS receives various fault information, the information is uploaded to the cloud and saved, and at the same time, the PCS is controlled to change from the current charging and discharging state to the stop charging and discharging state.

6. The method of claim 5, wherein the method further comprises: In step S2, the power-off detection module compares the output voltage of the AC-DC module with the +3V3 voltage through the comparator U1, outputs a corresponding level signal, and makes the MCU detect the change of the IO signal.

7. The method of claim 5, wherein the method further comprises: In step S3, the on-board super capacitor module charges the super capacitor C1 when the AC-DC module normally supplies power, and supplies power to the system through the boost circuit, the MOS tube Q2 and the MOS tube Q4 after power-off.

8. The method of claim 5, wherein the method further comprises: In step S4, after the EMS schedules to shut down the charging and discharging, the PCS or the power-off detection module sends a stop working signal to the BMS, and the BMS controls the main positive contactor of the high-voltage box to be disconnected.

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