Direct-current high-voltage rapid plugging connection method applied to energy storage system

Abstract

The invention provides a direct-current high-voltage quick plug-in connection method applied to an energy storage system, which comprises the following steps of: S1, mounting a direct-current high-voltage large-current quick plug-in female head on an energy storage battery container and an energy storage converter, and arranging a control detection device in a convergence cabinet of the energy storage battery container; s2, after the energy storage system is transported to a deployment area, connecting the energy storage system by using a connecting cable made of a quick connector male head and a high-voltage cable; and S3, after connection is completed, an interlocking device arranged in the connector starts to feed back a connection state, after connection is confirmed to be completed, an insulation detection device is started to carry out insulation self-inspection, and after the insulation state is completed, a battery system convergence circuit breaker / contactor is fed back to be closed, and power transmission is carried out. According to the invention, the quick connection and safe deployment of the power cable are realized by adopting the quick-plug connection and the fool-proof clamping and locking plug, and the high-voltage interlocking of the power cable connection and the insulation self-inspection and grounding self-inspection after the connection of the connector assembly can be realized, so that the safety of the cable after the plugging connection is ensured.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a direct current high voltage quick plug-in connection method applied to an energy storage system. Background Art

[0002] my country has made major adjustments to its energy structure, and energy storage batteries have become key equipment for my country's energy transformation. The system's large-scale energy storage power station containers are connected by DC power cables, which require laying and insulation withstand voltage testing. The deployment cycle is long and is not suitable for emergency energy storage power supply, mobile energy storage charging and other energy storage power station application scenarios that require temporary deployment.

[0003] At present, the mainstream electrochemical energy storage power station (BESS) deployed at the MW level uses a DC1500V battery system as the DC side, and the connection between the DC battery side and the energy storage converter is connected by a DC power cable. As the string energy storage system technology route gradually becomes the mainstream of the market, and the high-power / large-capacity technology route of the energy storage system develops, the number of power cables will increase, and the number of cables that need to be laid and connected will increase. Therefore, it is necessary to provide a quick plug-in connection device and method that can be applied to temporary deployment power stations, which can be applied to temporary deployment energy storage power stations, and can be applied to traditional energy storage power stations to improve deployment efficiency and safety.

[0004] In addition, after the power cable is laid, construction workers need to conduct an insulation withstand voltage test to check the safety of the power system before operation. The existing insulation withstand voltage test has complicated steps, low test efficiency and accuracy, and there are certain safety hazards. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention proposes a DC high-voltage quick plug-in connection method for an energy storage system, which adopts a quick-plug connection and a fool-proof card lock connector to achieve quick connection and safe deployment of power cables, and can realize high-voltage interlocking of the power cable connection and insulation self-check and grounding self-check after the connector is connected to ensure the safety of the cable after plug-in connection.

[0006] The control device of the present invention can be configured with two working modes: online insulation detection and offline insulation detection. At the same time, the temperature of the connection can be detected online in real time. The temperature threshold can be configured according to the length algorithm to realize real-time detection of the operating status.

[0007] To implement the above technical solution, the present invention provides a DC high voltage quick plug connection method applied to an energy storage system, which specifically includes the following steps:

[0008] S1. Install the female DC high-voltage and high-current fast connector on the energy storage battery container and the energy storage converter, and the control and detection device is built into the energy storage battery container junction cabinet;

[0009] S2. After the energy storage system is transported to the deployment area, it is connected using a connection cable made of a quick connector male head and a high-voltage cable. The quick connector male head with a fool-proof lock is docked with the quick connector female head. If it is not connected correctly, it cannot be connected;

[0010] S3. After the connection is completed, the built-in interlocking device of the connector starts to feedback that the connection status is normal. After the connection is confirmed, the insulation detection device is started to perform insulation self-test. After the insulation status is completed, the battery system busbar breaker / contactor is closed and power is transmitted.

[0011] Preferably, in step S3, two insulation detection states, online / offline, are set according to demand during the power transmission process. When the online detection state is used, the insulation state is monitored in real time by injecting a low-frequency signal into the detection circuit through an online device; when the offline detection state is used, the insulation state is monitored by the insulation impedance detection circuit of the unbalanced bridge after the battery is connected offline. At the same time, the temperature threshold is configured according to the length algorithm, and the connection point temperature is monitored in real time online. An abnormality is fed back to alarm and the battery is disconnected.

[0012] Preferably, the low-frequency signal injection detection circuit in step S3 specifically includes: a positive electrode insulation resistor R+, a negative electrode insulation resistor R-, a DC power supply Battery, a capacitor C, a resistor R and a low-frequency signal generator Gen of the energy storage system, wherein one end of the positive electrode insulation resistor R+ is connected to the positive electrode of the DC power supply Battery, the other end of the positive electrode insulation resistor R+ is connected to the low-frequency signal generator Gen, one end of the negative electrode insulation resistor R- is connected to the negative electrode of the DC power supply Battery, the other end of the negative electrode insulation resistor R- is grounded, and one end of the capacitor C is connected to the connection line between the positive electrode insulation resistor R+ and the positive electrode of the DC power supply Battery , the other end of capacitor C is connected to resistor R, sampling point A is set on the line connecting capacitor C and resistor R, and the other end of resistor R is connected to low-frequency signal generator Gen; in the detection process, after low-frequency signal generator Gen sends out low-frequency square wave signal, it is divided into two stages. In the first stage, when +5V voltage is sent, capacitor C is in the charging process. In the second stage, the signal generator sends out 0V signal, which is equivalent to short-circuiting low-frequency signal generator Gen, and capacitor C starts to discharge. During the charging time of capacitor C, the positive insulation resistance R+ and the negative insulation resistance R- form a total parallel resistance R′ and the resistor R to form a voltage divider, where the voltage to ground on the resistor R′ is V 1 , the voltage to ground on the resistor R is V 2 , and V 1 +V 2=5V, the voltage signal collected at point A is divided into 2 areas and 2 moments in a square wave cycle. The first moment is the discharge voltage division moment, the second part of the area is the RC discharge area, the third moment is the charge voltage division moment, and the fourth part of the area is the charge voltage division area. The voltage signal from point A to the ground is collected by the A / D sampling module of the microcontroller. The size of the jump voltage U in the charge voltage division area is selected in the detection, and then the obtained data is calculated by formula 1 to obtain the size of the insulation resistance.

[0013]

[0014] Among them, the voltage across the parallel insulation resistance R' is V 1 , the voltage across the standard resistor R is V 2 .

[0015] Preferably, the insulation impedance detection circuit of the unbalanced bridge in step S3 specifically includes: a ground resistance Rx of the positive electrode of the energy storage battery, a ground resistance Ry of the negative electrode of the energy storage battery, a balancing resistor R1, sampling resistors R2 and R3 of the voltage between the ground electrode of the energy storage battery and the earth, an electronic switch S1, and a BMS controller, wherein one end of Rx is connected to the positive electrode of the energy storage battery, and the other end of Rx is directly grounded, one end of Ry is connected to the negative electrode of the energy storage battery, and the other end of Ry is also directly grounded, the balancing resistor R1 is connected in series with the electronic switch S1 and then connected in parallel at both ends of Rx, and the resistor R2 is connected in series with R3 and then connected in parallel at both ends of Ry. In the detection process, by controlling the on and off of the electronic switch S1, different modes of the circuit are constructed to collect the voltage U of the earth to GND. GO And the open circuit voltage U V , and write the node current equation of point G according to Kirchhoff's law,

[0016] When S1 is turned off, the equation is as shown in Formula 2:

[0017]

[0018] Where: U GO,0 is the voltage between ground and GND when S1 is turned off; UV is the open circuit voltage of the energy storage battery;

[0019] When S1 is turned on, the equation is as shown in Formula 3:

[0020]

[0021] Where: U GO,1 It is the voltage between ground and GND when S1 is on.

[0022] Preferably, the specific manner of configuring the temperature threshold according to the length algorithm in step S3 is as follows:

[0023] S31, obtaining a length value L according to the actual requirements of the system operation;

[0024] S32, according to the input length value L, the corresponding temperature threshold T is calculated according to the preset length algorithm formula T=A×L+B, where A represents the coefficient of the influence of the length on the temperature threshold, and B represents the reference temperature value, which is the initial temperature when the length is zero;

[0025] S33, set the upper and lower limits of temperature T min and T max When the calculated temperature T exceeds the set safety range T min and T max , limit T to T min and T max Ensure that the temperature value always remains within the safe working range;

[0026] S34. The system continuously monitors the temperature value and detects the temperature in real time according to the calculated temperature threshold T. If the actual temperature exceeds the set temperature threshold, an alarm is immediately triggered and the system enters the protection mode.

[0027] Preferably, the female quick connector includes a female socket, a female anti-foolproof lock is provided on the end edge of the female socket, a female PE jack is provided in the center of the female socket, female HVIL jacks are provided on the left and right sides of the female PE jack, female DC positive jacks are provided at the upper left corner and the upper right corner of the female PE jack, and female DC negative jacks are provided at the lower left corner and the lower right corner of the female PE jack.

[0028] Preferably, the male head of the quick connector includes a male socket, a male anti-foolproof lock corresponding to the female anti-foolproof lock is arranged on the end edge of the male socket, a male PE pin corresponding to the female PE socket is arranged in the center of the male socket, male HVIL pins corresponding to the female HVIL socket are arranged on the left and right sides of the male PE pin, male DC positive pins corresponding to the female DC positive socket are arranged at the upper left corner and the upper right corner of the male PE socket, and male DC negative pins corresponding to the female DC negative socket are arranged at the lower left corner and the lower right corner of the male PE socket.

[0029] The beneficial effects of a DC high voltage quick plug connection method applied to an energy storage system provided by the present invention are:

[0030] (1) The present invention uses a quick connector male head with an anti-foolproof lock to connect with a quick connector female head, which can achieve rapid connection and safe deployment of power cables.

[0031] (2) The control system configured in the present invention can realize high-voltage interlocking of power cable connections and insulation self-checking and grounding self-checking after connector connection to ensure the safety of cable connection, greatly improving the efficiency and safety of energy storage power station deployment.

[0032] (3) The present invention is equipped with two working modes: online insulation detection and offline insulation detection. At the same time, the temperature detection of the connection point is carried out in real time online. The temperature threshold can be configured according to the length algorithm to realize real-time detection of the operating status, further ensuring the correct status of the power cable during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flow chart of the present invention.

[0034] Figure 2 It is a schematic diagram of the structure of the female head of the quick connector in the present invention.

[0035] Figure 3 It is a schematic structural diagram of the male head of the quick connector in the present invention.

[0036] Figure 4 It is a connection diagram of the power cable in the present invention.

[0037] Figure 5 This is a circuit diagram of low-frequency signal injection detection in the present invention.

[0038] Figure 6 This is a simplified circuit diagram of the low-frequency signal injection detection circuit of the present invention after the DC voltage source is short-circuited.

[0039] Figure 7 This is a voltage signal diagram collected at point A in the present invention.

[0040] Figure 8 This is an insulation impedance detection circuit based on an unbalanced bridge in the present invention.

[0041] In the figure: 1. Female quick connector; 11. Female socket; 12. Female anti-fool-proof lock; 13. Female DC positive jack; 14. Female DC negative jack; 15. Female HVIL jack; 16. Female PE jack; 2. Male quick connector; 21. Male socket; 22. Male anti-fool-proof lock; 23. Male DC positive pin; 24. Male DC negative pin; 25. Male HVIL pin; 26. Male PE pin. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary persons in the art without creative work are within the scope of protection of the present invention.

[0043] Embodiment: A DC high voltage quick plug connection method applied to an energy storage system.

[0044] Reference Figures 1 to 4 As shown, a DC high voltage quick plug connection method applied to an energy storage system specifically includes the following steps:

[0045] S1. Install the DC high-voltage and high-current quick connector female connector 1 on the energy storage battery container and the energy storage converter. The quick connector female connector 1 includes a female socket 11. A female anti-foolproof lock 12 is arranged on the end edge of the female socket 11. A female PE socket 16 is arranged at the center of the female socket 11. Female HVIL sockets 15 are arranged on the left and right sides of the female PE socket 16. Female DC positive sockets 13 are arranged at the upper left and upper right corners of the female PE socket 16, respectively. Female DC positive sockets 13 are arranged at the lower left and upper right corners of the female PE socket 16. A female DC negative pole jack 14 is provided at the lower right corner, and a female quick connector 1 with a female anti-foolproof lock 12 is installed on the energy storage battery container and the energy storage converter to facilitate the subsequent fast and accurate docking with a male quick connector 2 with a male anti-foolproof lock 22. The control detection device is built into the energy storage battery container junction cabinet. The control detection device can realize the high-voltage interlocking of the power cable connection and the insulation self-test and grounding self-test after the connector is connected to ensure the safety of the cable after the connection, thereby greatly improving the efficiency and safety of the energy storage power station deployment.

[0046] S2. After the energy storage system is transported to the deployment area, it is connected by a quick connector male 2 and a connecting cable made of a high-voltage cable. The quick connector male 2 with an anti-foolproof lock is docked with the quick connector female 1. If it is not connected correctly, it cannot be connected. The quick connector male 2 includes a male socket 21. The end edge of the male socket 21 is provided with a male anti-foolproof lock 22 corresponding to the female anti-foolproof lock 12. The center of the male socket 21 is provided with a male PE pin 26 corresponding to the female PE socket 16. The left side of the male PE pin 26 Both right sides are provided with male HVIL pins 25 corresponding to the female HVIL jack 14, the upper left corner and upper right corner of the male PE jack 26 are respectively provided with male DC positive pins 23 corresponding to the female DC positive jack 13, and the lower left corner and lower right corner of the male PE jack 26 are respectively provided with male DC negative pins 24 corresponding to the female DC negative jack 14; during actual docking, a quick connector male 2 with an anti-foolproof lock is used to connect with the quick connector female 3, so as to realize quick connection and safe deployment of the power cable.

[0047] S3. After the connection is completed, the built-in interlocking device of the connector starts to feedback the connection status. After the connection is confirmed, the insulation detection device is started to perform insulation self-test. After the insulation status is completed, the battery system busbar circuit breaker / contactor is closed and power is transmitted. During the power transmission process, the insulation online / offline detection states are set according to demand. When the online detection state is used, the insulation state is monitored in real time through the online device using a low-frequency signal injection detection circuit; when the offline detection state is used, the insulation state monitoring is fed back through the insulation impedance detection circuit of the unbalanced bridge after the battery is connected offline. At the same time, the temperature threshold is configured according to the length algorithm, and the temperature of the connection point is monitored online in real time. Abnormal feedback alarms and notification of battery disconnection.

[0048] Among them, the process of online insulation status monitoring is as follows:

[0049] The online insulation status detection adopts the low-frequency signal injection method, which is based on the new monitoring principle of the low-frequency signal injection method. The biggest feature of this method is that it is not affected by the DC power supply during measurement, and can be measured when running or stopped. In addition, because the insulation parallel resistance calculation is completely dependent on the A / D sampling value of the only point in the system, the structure of the entire system is relatively simple, the size of the insulation resistance meter is relatively small, and it has good operability in practical applications.

[0050] The detection circuit diagram of RC low-frequency signal injection method is as follows Figure 5As shown, it specifically includes: a positive insulation resistor R+, a negative insulation resistor R-, a DC power supply Battery, a capacitor C, a resistor R and a low-frequency signal generator Gen of the energy storage system, wherein one end of the positive insulation resistor R+ is connected to the positive electrode of the DC power supply Battery, the other end of the positive insulation resistor R+ is connected to the low-frequency signal generator Gen, one end of the negative insulation resistor R- is connected to the negative electrode of the DC power supply Battery, the other end of the negative insulation resistor R- is grounded, one end of the capacitor C is connected to the connection line between the positive insulation resistor R+ and the positive electrode of the DC power supply Battery, the other end of the capacitor C is connected to the resistor R, the sampling point A is set on the line connecting the capacitor C and the resistor R, and the other end of the resistor R is connected to the low-frequency signal generator Gen.

[0051] Figure 5 The overall model of the energy storage system is outside the dotted box, and the main circuit of the insulation detection system is inside the dotted box, which includes capacitor C, resistor R, and low-frequency signal generator Gen. Point A in the figure indicates the location of A / D sampling. From the knowledge of analog electronic circuits, we know that if an AC power supply is added to the circuit, a DC current source with very small internal resistance in the circuit can be regarded as a short circuit, and a current source with very large internal resistance can be regarded as an open circuit. Generally speaking, the internal resistance of the battery is at the mΩ level. When the voltage rises, the internal resistance of the battery is still very small. Based on this principle, when the signal generator Gen sends out an AC signal, the DC voltage source can be considered to be short-circuited, that is, Figure 6 The simplified circuit is shown.

[0052] Since the DC voltage source can be regarded as a short circuit, the positive insulation resistance R+ and the negative insulation resistance R- form a total parallel resistance (R' in the figure). According to the series-parallel equivalent principle in the circuit, R'<min[R-, R+]. If the R' resistance value can be guaranteed to meet the national insulation resistance standard in the circuit, the safety of the energy storage system can be ensured.

[0053] During the detection process, after the signal generator sends out a low-frequency square wave signal, this process can be divided into two stages. In the first stage, when a +5V voltage is sent, capacitor C is in the charging process. In the second stage, the signal generator sends out a 0V signal, which is equivalent to a short circuit of the signal generator, and capacitor C begins to discharge. During the charging time of capacitor C, the detection resistor R' forms a voltage divider with the resistor R, where the voltage to ground on the resistor R' is V 1 , the voltage to ground on the resistor R is V 2 , and V 1 +V 2 =5V, the voltage signal collected at point A is as follows Figure 7 shown.

[0054] exist Figure 7In the figure, the upper signal is a square wave signal, and the lower signal is the signal collected at point A. In one square wave cycle, it can be divided into 2 areas and 2 moments. The first moment is shown in 1, which is called the discharge voltage division moment. The second part of the area is the RC discharge area. The third moment is shown in 3, which is the charge voltage division moment. The fourth part of the area is the charge voltage division area. The voltage signal from point A to the ground is collected by the A / D sampling module of the microcontroller. The size of the jump voltage U in the charge voltage division area is selected in the detection. The data obtained can be calculated through formula 1 to obtain the size of the insulation resistance. Figure 6 As shown, the voltage across the parallel insulation resistance R′ is V 1 , the voltage across the standard resistor R is V 2 .

[0055]

[0056] The process of offline insulation condition monitoring is as follows:

[0057] Insulation impedance detection circuit based on unbalanced bridge Figure 8 As shown, EARTH on the right side of the figure represents the earth, and GND on the left side is the system ground, which specifically includes: the ground resistance Rx of the positive electrode of the energy storage battery, the ground resistance Ry of the negative electrode of the energy storage battery, the balancing resistor R1, the sampling resistors R2 and R3 of the voltage between the ground electrode of the energy storage battery and the earth, the electronic switch S1, and the BMS controller, wherein one end of Rx is connected to the positive electrode of the energy storage battery, and the other end of Rx is directly grounded, one end of Ry is connected to the negative electrode of the energy storage battery, and the other end of Ry is also directly grounded, the balancing resistor R1 is connected in series with the electronic switch S1 and then connected in parallel at both ends of Rx, and the resistors R2 and R3 are connected in series and then connected in parallel at both ends of Ry.

[0058] Among them, energy storage batteries are generally used for system monitoring and control, and the voltage sampling results can be used for insulation impedance calculation. Rx and Ry represent the ground resistance of the positive and negative electrodes of the energy storage battery, respectively, which is the insulation resistance to be detected. The balancing resistor R1 is connected in series with the electronic switch S1 and then connected in parallel at both ends of Rx. R2 and R3 are sampling resistors for the voltage between the ground electrode of the energy storage battery and the earth. The sampled voltage is input into the BMS controller after the calculation and conditioning circuit.

[0059] In actual operation, by controlling the on and off of the electronic switch S1, different modes of the circuit are constructed, and the node current equation of point G is written according to Kirchhoff's law.

[0060] When S1 is turned off, the equation is as shown in Formula 2:

[0061]

[0062] Where: U GO,0 is the voltage between ground and GND when S1 is turned off; UV is the open circuit voltage of the energy storage battery;

[0063] When S1 is turned on, the equation is as shown in Formula 3:

[0064]

[0065] Where: U GO,1 It is the voltage between ground and GND when S1 is on.

[0066] The specific method of configuring the temperature threshold based on the length algorithm is as follows:

[0067] First, a length value L (the distance between the sensor and the insulator) is obtained according to the actual needs of the system operation;

[0068] Then, according to the input length value L, the corresponding temperature threshold T is calculated according to the preset length algorithm formula T=A×L+B, where A represents the coefficient of the influence of the length on the temperature threshold, and B represents the reference temperature value, which is the initial temperature when the length is zero;

[0069] Then, since the safe operation of the equipment requires a temperature threshold T to meet a certain safety range, the upper and lower limits of the temperature T are set. min and T max When the calculated temperature T exceeds the set safety range T min and T max , limit T to T min and T max To ensure that the temperature value always remains within the safe working range;

[0070] Finally, the system continuously monitors the temperature value and performs real-time temperature detection based on the calculated temperature threshold T. If the actual temperature exceeds the set temperature threshold, the alarm is immediately triggered and the system enters the protection mode to prevent equipment damage or safety accidents.

[0071] The specific process is as follows:

[0072] Step 1: The device measures the temperature by installing temperature sensors (such as thermocouples, thermistors, and infrared temperature sensors) on the surface or inside the cable. When the surface temperature of the cable changes, the sensor senses the temperature change and generates a corresponding electrical signal. After amplification, filtering, and linearization, these electrical signals are transmitted to the monitoring system through the signal transmission line. The monitoring system will analyze and process the received signal and display the temperature value T of the cable. actual ;

[0073] Step 2: Measure the distance between the temperature sensor and the insulator to obtain the length value L, configure the coefficient A of the length effect on the temperature threshold, calculate the temperature threshold T according to the length algorithm formula T = A × L + B, and compare it with the actual temperature T measured by the temperature sensor actual and the temperature threshold T calculated by applying the length algorithm;

[0074] Step 3: If T actual Exceeds the set upper limit T max Or below the lower limit T min , the temperature warning mechanism is triggered and the device enters protection mode to prevent equipment damage or safety accidents.

[0075] The present invention is equipped with two working modes: online insulation detection and offline insulation detection. At the same time, the temperature detection of the connection is real-time online. The temperature threshold can be configured according to the length algorithm to realize real-time detection of the operating status, further ensuring the correct status of the power cable during operation.

[0076] The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the contents disclosed in the embodiment and the drawings, so any equivalent or modification completed without departing from the spirit disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. A DC high voltage quick plug connection method for energy storage system, characterized in that The specific steps include: S1. Install the female DC high-voltage and high-current fast connector on the energy storage battery container and the energy storage converter, and the control and detection device is built into the energy storage battery container junction cabinet; S2. After the energy storage system is transported to the deployment area, it is connected using a connection cable made of a quick connector male head and a high-voltage cable. The quick connector male head with a fool-proof lock is docked with the quick connector female head. If it is not connected correctly, it cannot be connected; S3. After the connection is completed, the built-in interlocking device of the connector starts to feedback that the connection status is normal. After the connection is confirmed, the insulation detection device is started to perform insulation self-test. After the insulation status is completed, the battery system busbar breaker / contactor is closed and power is transmitted.

2. The DC high voltage quick plug connection method for energy storage system according to claim 1, characterized in that: In the step S3, two insulation detection states, online / offline, are set according to demand during the power transmission process. When the online detection state is used, the real-time insulation state monitoring is performed by injecting a low-frequency signal into the detection circuit through the online device; When using the offline detection state, after the battery is connected offline, the insulation status monitoring is fed back through the insulation impedance detection circuit of the unbalanced bridge. At the same time, the temperature threshold is configured according to the length algorithm, and the connection point temperature is monitored online in real time. Abnormal feedback alarms and notifies the battery to disconnect.

3. The DC high voltage quick plug connection method for energy storage system according to claim 2, characterized in that: The low-frequency signal injection detection circuit in step S3 specifically includes: a positive electrode insulation resistor R+, a negative electrode insulation resistor R-, a DC power supply Battery, a capacitor C, a resistor R and a low-frequency signal generator Gen of the energy storage system, wherein one end of the positive electrode insulation resistor R+ is connected to the positive electrode of the DC power supply Battery, the other end of the positive electrode insulation resistor R+ is connected to the low-frequency signal generator Gen, one end of the negative electrode insulation resistor R- is connected to the negative electrode of the DC power supply Battery, the other end of the negative electrode insulation resistor R- is grounded, one end of the capacitor C is connected to the connection line between the positive electrode insulation resistor R+ and the positive electrode of the DC power supply Battery, the other end of the capacitor C is connected to the resistor R, the sampling point A is set on the line connecting the capacitor C and the resistor R, and the other end of the resistor R is connected to the low-frequency signal generator Gen; in the detection process, after the low-frequency signal generator Gen sends a low-frequency square wave signal, it is divided into two stages In the first stage, when +5V voltage is sent, capacitor C is in the charging process. In the second stage, the signal generator sends a 0V signal, which is equivalent to the low-frequency signal generator Gen being short-circuited, and capacitor C starts to discharge. During the charging time of capacitor C, the positive insulation resistance R+ and the negative insulation resistance R- form a total parallel resistance R' and a voltage divider with the resistor R, where the voltage to ground on the resistor R' is V1, the voltage to ground on the resistor R is V2, and V1+V2=5V. The voltage signal collected at point A is divided into 2 areas and 2 moments within a square wave cycle. The first moment is the discharge voltage divider moment, the second part of the area is the RC discharge area, the third moment is the charge voltage divider moment, and the fourth part of the area is the charge voltage divider area. The voltage signal from point A to ground is collected by the A / D sampling module of the microcontroller. The size of the jump voltage U in the charge voltage divider area is selected in the detection, and the obtained data is calculated by formula 1 to obtain the size of the insulation resistance. The voltage across the parallel insulation resistor R′ is V1, and the voltage across the standard resistor R is V2.

4. The DC high voltage quick plug connection method for energy storage system according to claim 2, characterized in that: The insulation impedance detection circuit of the unbalanced bridge in step S3 specifically includes: a ground resistance Rx of the positive electrode of the energy storage battery, a ground resistance Ry of the negative electrode of the energy storage battery, a balancing resistor R1, sampling resistors R2 and R3 of the voltage between the ground electrode of the energy storage battery and the earth, an electronic switch S1, and a BMS controller, wherein one end of Rx is connected to the positive electrode of the energy storage battery, and the other end of Rx is directly grounded, one end of Ry is connected to the negative electrode of the energy storage battery, and the other end of Ry is also directly grounded, the balancing resistor R1 is connected in series with the electronic switch S1 and then connected in parallel at both ends of Rx, and the resistors R2 and R3 are connected in series with each other and then connected in parallel at both ends of Ry. In the detection process, by controlling the on and off of the electronic switch S1, different modes of the circuit are constructed to collect the voltage U of the earth to GND. GO And the open circuit voltage U V , and write the node current equation of point G according to Kirchhoff's law, When S1 is turned off, the equation is as shown in Formula 2: Where: U GO,0 is the voltage between ground and GND when S1 is turned off; U V It is the open circuit voltage of the energy storage battery; When S1 is turned on, the equation is as shown in Formula 3: Where: U GO,1 It is the voltage between ground and GND when S1 is on.

5. The DC high voltage quick plug connection method for energy storage system according to claim 2, characterized in that: The specific method of configuring the temperature threshold according to the length algorithm in step S3 is as follows: S31, obtaining a length value L according to the actual requirements of the system operation; S32, according to the input length value L, the corresponding temperature threshold T is calculated according to the preset length algorithm formula T=A×L+B, where A represents the coefficient of the influence of the length on the temperature threshold, and B represents the reference temperature value, which is the initial temperature when the length is zero; S33, set the upper and lower limits of temperature T min and T max When the calculated temperature T exceeds the set safety range T min and T max , limit T to T min and T max Ensure that the temperature value always remains within the safe working range; S34. The system continuously monitors the temperature value and detects the temperature in real time according to the calculated temperature threshold T. If the actual temperature exceeds the set temperature threshold, an alarm is immediately triggered and the system enters the protection mode.

6. The DC high voltage quick plug connection method for energy storage system according to claim 1, characterized in that: The female quick connector includes a female socket, a female anti-foolproof lock is arranged on the end edge of the female socket, a female PE jack is arranged in the center of the female socket, female HVIL jacks are arranged on the left and right sides of the female PE jack, female DC positive jacks are arranged at the upper left corner and the upper right corner of the female PE jack, and female DC negative jacks are arranged at the lower left corner and the lower right corner of the female PE jack.

7. The DC high voltage quick plug connection method for energy storage system according to claim 6, characterized in that: The male plug of the quick connector includes a male socket, a male anti-foolproof lock corresponding to the female anti-foolproof lock is arranged on the end edge of the male socket, a male PE pin corresponding to the female PE socket is arranged in the center of the male socket, male HVIL pins corresponding to the female HVIL socket are arranged on the left and right sides of the male PE pin, male DC positive pins corresponding to the female DC positive socket are arranged at the upper left corner and the upper right corner of the male PE socket, and male DC negative pins corresponding to the female DC negative socket are arranged at the lower left corner and the lower right corner of the male PE socket.

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