Combined pre-charging circuit of energy storage high-voltage box and control method

Abstract

The invention relates to a combined pre-charging circuit of an energy storage high-voltage box and a control method, the combined pre-charging circuit of the energy storage high-voltage box is used for establishing electric connection between a battery cluster and an energy storage system, the positive electrode of the battery cluster is connected with the positive electrode of the energy storage system through a positive electrode path, and the negative electrode of the battery cluster is connected with the negative electrode of the energy storage system through a negative electrode path. The combined pre-charging circuit comprises a positive fuse, a negative fuse, a shunt, a pre-charging resistor, a combined pre-charging module and a battery cluster control module; the combined pre-charging module comprises a pre-charging switch group and a main switch group, the pre-charging switch group comprises a first positive pole switch piece and a first negative pole switch piece which act synchronously, and the main switch group comprises a second positive pole switch piece and a second negative pole switch piece which act synchronously; the positive fuse is connected to the positive path; and the negative fuse and the shunt are connected in series to the negative path. The combined pre-charging circuit of the energy storage high-voltage box can greatly reduce the usage amount of electrical equipment, and can reduce the fault rate of the energy storage high-voltage box.

Description

Technical Field

[0001] The present disclosure relates to the technical field of energy storage circuits, and in particular to a combined pre-charging circuit and a control method for an energy storage high-voltage box. Background Art

[0002] The energy storage high-voltage box is a high-voltage circuit management module that connects the battery cluster and the energy storage inverter / system cabinet. It has functions such as battery cluster voltage / current collection, drive contactor and protection. Currently, most of the energy storage high-voltage box circuits on the market are mainly composed of: fuses, main positive contactors, main negative contactors, pre-charge contactors, pre-charge resistors, and DC isolation switches. When the system is running, these contactors and isolation switches need to undergo a series of precise linkage actions to ensure the smooth conduction of the main circuit.

[0003] Although these components together build a safety line of defense for the energy storage high-voltage box, due to its unique structural characteristics, the contactor is often prone to problems such as contactor adhesion and malfunction. The more contactors there are, the higher the failure rate of the system. This not only poses a severe test to the normal connection of the high-voltage box, but also increases the maintenance burden and cost investment of electrical equipment. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present disclosure is to provide a combined pre-charging circuit and control method of an energy storage high-voltage box. The combined pre-charging circuit of the energy storage high-voltage box adopts a combined pre-charging module in the combined pre-charging circuit of the energy storage high-voltage box. Compared with the traditional control circuit using three contactors plus a DC isolating switch, the linkage and coordination problems between multiple contactors in the traditional circuit are reduced, which can greatly reduce the use of electrical equipment and save material costs; the number of circuit action devices is reduced, and the failure rate of the energy storage high-voltage box can be reduced while ensuring the normal operation of the circuit. The overall performance stability of the circuit has been significantly improved, which helps to reduce circuit anomalies caused by contactor failure or malfunction, thereby improving the overall operation efficiency of the energy storage high-voltage box.

[0005] The combined pre-charging circuit and control method of the energy storage high-voltage box disclosed in the present invention are used to establish an electrical connection between a battery cluster and an energy storage system, wherein the positive electrode of the battery cluster is connected to the positive electrode of the energy storage system through a positive electrode path, and the negative electrode of the battery cluster is connected to the negative electrode of the energy storage system through a negative electrode path. The combined pre-charging circuit includes a positive electrode fuse, a negative electrode fuse, a shunt, a pre-charging resistor, a combined pre-charging module, and a battery cluster control module;

[0006] The combined pre-charging module comprises a pre-charging switch group and a main switch group, wherein the pre-charging switch group comprises a first positive switch element and a first negative switch element that act synchronously, and the main switch group comprises a second positive switch element and a second negative switch element that act synchronously;

[0007] The positive electrode fuse is connected to the positive electrode path, the first positive electrode switch element and the second positive electrode switch element are connected to the positive electrode path, and are used to control the on and off of the positive electrode path, and the pre-charging resistor is connected in series with the first positive electrode switch element;

[0008] The negative electrode fuse and the shunt are connected in series to the negative electrode path, and the first negative electrode switch and the second negative electrode switch are connected to the negative electrode path in parallel, so as to control the on and off of the negative electrode path;

[0009] The battery cluster control module is respectively connected to the shunt, the combined pre-charging module and the energy storage system by signals.

[0010] A combined pre-charging circuit control method for an energy storage high-voltage box is applied to the combined pre-charging circuit of the energy storage high-voltage box as described above, wherein the battery cluster control module controls the closing and opening of the combined pre-charging module according to the power-on and power-off processes of the energy storage high-voltage box to realize the power-on and power-off of the energy storage high-voltage box.

[0011] Preferably, the power-on process includes the following steps:

[0012] S101, performing a power supply test on the energy storage high-voltage box and an electrical performance test on each battery in the battery cluster, and in an initial state, the pre-charge switch group and the main switch group are both in a disconnected state;

[0013] S102, performing adhesion detection on the pre-filling switch group, and closing the pre-filling switch group after the adhesion detection is normal;

[0014] S103, pre-charging;

[0015] S104, after the pre-charging is completed, the battery cluster control module controls the main switch group to close;

[0016] S105, disconnecting the pre-charging switch group to complete powering on the energy storage high-voltage box.

[0017] Preferably, in step S101, the power supply test specifically includes:

[0018] The power supply test includes insulation performance testing and circuit performance testing;

[0019] The insulation performance test comprises the following steps:

[0020] Get the total voltage U of the battery cluster Z , the insulation resistance value R1 between the positive electrode of the battery cluster and the external exposed conductive part, and the insulation resistance value R2 between the negative electrode of the battery cluster and the external exposed conductive part;

[0021] If R1>1000*U Z And R2>1000*U Z , the insulation performance meets the requirements, and the circuit performance test is performed;

[0022] If R1>1000*U Z And R2≤1000*U Z , the insulation performance does not meet the requirements, an alarm message is issued, and an output is output that the insulation performance between the negative electrode of the battery cluster and the external exposed conductive part does not meet the requirements;

[0023] If R1≤1000*U Z And R2>1000*U Z , the insulation performance does not meet the requirements, an alarm message is issued, and an output is output that the insulation performance between the positive electrode of the battery cluster and the external exposed conductive part does not meet the requirements;

[0024] If R1≤1000*U Z And R2≤1000*U Z , the insulation performance does not meet the requirements, an alarm message is issued, and an output is output that the insulation performance between the positive electrode of the battery cluster and the external exposed conductive part, and between the negative electrode of the battery cluster and the external exposed conductive part both do not meet the requirements;

[0025] The circuit performance detection comprises the following steps:

[0026] Get the voltage value U of the circuit S , current value I S , Ambient temperature value W H , and the surface temperature value W of the energy storage high-voltage box C , and calculate the circuit performance coefficient E according to the following formula S :

[0027]

[0028] Among them, U L is the theoretical initial voltage value; △U Lmax is the theoretical voltage difference; I L is the theoretical initial current value; △I Lmax is the theoretical current difference; W LCmax is the theoretical maximum surface temperature of the energy storage high-voltage box; a1, a2 and a3 are all weight coefficients, and satisfy a1+a2+a3=1;

[0029] If 0.9≤E S ≤1.1, the circuit performance test is qualified and the power supply test is judged to have passed;

[0030] If E S<0.9 or E S >1.1, the circuit performance test fails, an alarm message is issued, and the power supply test is judged to have failed.

[0031] Preferably, in step S101, the electrical performance test includes the following steps:

[0032] The electrical performance test includes calculating an actual battery state of charge value SOC and an actual battery health state value SOH of a single battery, and judging whether the electrical performance test is passed according to the calculation results;

[0033] Collect the initial charge value SOC0 of a single battery in the battery cluster, a charge and discharge cycle time t of the battery, the current value I within a charge and discharge cycle time t, the total capacity C of a single battery, and the actual capacity value Q of a single battery d , get the theoretical battery state of charge value SOC L And the theoretical battery health status SOH L ;

[0034] Divide a charge and discharge cycle time t into M time periods according to equal time intervals △t, and obtain the average current value of each time period Calculate the actual battery state of charge value SOC and the actual battery health state value SOH:

[0035]

[0036] Among them, Q n is the theoretical initial rated capacity value of a single battery; △t<t;

[0037] If SOC=[0.85*SOC L , 1.15*SOC L ] and SOH = [0.90*SOH L , 1.10*SOH L ], it is judged that the electrical performance test has passed;

[0038] If SOC≠[0.85*SOC L , 1.15*SOC L ] and SOH = [0.90*SOH L , 1.10*SOH L ], it is determined that the electrical performance test fails, an alarm message is issued, and abnormal information of the actual battery state of charge value SOC is output;

[0039] If SOC=[0.85*SOC L , 1.15*SOC L ] and SOH≠[0.90*SOH L, 1.10*SOH L ], it is determined that the electrical performance test fails, an alarm message is issued, and the actual battery health status value SOH abnormal information is output;

[0040] If SOC≠[0.85*SOC L , 1.15*SOC L ] and SOH≠[0.90*SOH L , 1.10*SOH L ], it is judged that the electrical performance test fails, an alarm message is issued, and the actual battery power state value SOC abnormal information and the actual battery health state value SOH abnormal information are output.

[0041] Preferably, the step S102 specifically includes:

[0042] After both the power supply test and the electrical performance test are passed, performing adhesion detection on the pre-charging switch group;

[0043] After the adhesion detection is passed, the battery cluster control module sends a pre-charge instruction and closes the pre-charge switch group.

[0044] Preferably, the step S103 specifically includes:

[0045] Set the pre-charge time T Y , during the precharge time T Y Execute the pre-charging process internally;

[0046] After the pre-charging process is completed, the total voltage value U of the circuit between the battery cluster and the main switch group is measured. Z , and judging whether the pre-charging process meets the pre-charging requirements;

[0047] If U Z ≥90%*U CZ , it is determined that the pre-charging requirements are met, and the battery cluster control module sends a pre-charging success instruction to complete the pre-charging;

[0048] If U Z <90%*U CZ , it is judged that the pre-charging requirement is not met, a new pre-charging time is reset, and pre-charging is performed according to the new pre-charging time until the pre-charging requirement is met;

[0049] Among them, U CZ Indicates the total voltage value of the battery cluster.

[0050] Preferably, the step S105 specifically includes:

[0051] Set the waiting time T DAfter the battery cluster control module controls the main switch group to close, the waiting time T D After that, the current value I at both ends of the pre-charge switch group is detected. YC and the current value I across the main switch group ZC , judging the normality of the circuit connection state, and judging that the circuit connection state is normal as completing the power-on of the energy storage high-voltage box;

[0052] If I YC =0 and I ZC ≠0, it is judged that the circuit connection state is normal, and the power-on completion information of the energy storage high-voltage box is output;

[0053] If I YC ≠0 and I ZC ≠0, it is judged that the circuit connection state is abnormal, an alarm message is issued, and the information that the pre-charging switch group is not disconnected is output;

[0054] If I YC =0 and I ZC =0, the circuit connection state is judged to be abnormal, an alarm message is issued, and the main switch group is not connected information is output;

[0055] If I YC ≠0 and I ZC =0, the circuit connection state is judged to be abnormal, an alarm message is issued, and the information that the pre-charging switch group is not disconnected and the main switch group is not connected is output.

[0056] Preferably, the power-off process includes the following steps:

[0057] S201, stopping the operation of the energy storage terminal and powering off the energy storage high-voltage box;

[0058] S202, the battery cluster control module receives a power-off instruction, disconnects the main switch group, and determines whether the disconnection is normal;

[0059] S203: After the main switch group is normally disconnected, the energy storage high-voltage box is powered off.

[0060] Preferably, the step S202 specifically includes:

[0061] The battery cluster control module receives the power-off instruction, disconnects the main switch group, and determines whether the main switch group is disconnected normally, and the determination method is as follows:

[0062] Set the detection period T J , the detection period T J Divide N detection time points t into equal time intervals i (i=0,1,2…N), each detection time point t iDetect the voltage value U across the main switch group Fi and current value I Fi (i=0,1,2…N), with t0 as the initial time, U detected at t0 F0 and I F0 are the initial detection voltage and current values ​​respectively, and the power-down coefficient K is calculated according to the following formula D :

[0063]

[0064] If I F0 = 0 and K D =0, it is judged that the main switch is normally disconnected;

[0065] If I F0 ≠0 or K D ≠0, it is determined that the main switch is not disconnected normally and an alarm message is issued.

[0066] The advantages of the combined pre-charging circuit and control method of the energy storage high-voltage box disclosed in the present invention are:

[0067] 1. A combined pre-charging circuit of an energy storage high-voltage box disclosed in the present invention is used to establish an electrical connection between a battery cluster and an energy storage system. The positive electrode of the battery cluster is connected to the positive electrode of the energy storage system through a positive electrode path, and the negative electrode of the battery cluster is connected to the negative electrode of the energy storage system through a negative electrode path. The combined pre-charging circuit includes a positive electrode fuse, a negative electrode fuse, a shunt, a pre-charging resistor, a combined pre-charging module and a battery cluster control module; the combined pre-charging module includes a pre-charging switch group and a main switch group, the pre-charging switch group includes a first positive electrode switch element and a first negative electrode switch element that act synchronously, and the main switch The group includes a second positive switch element and a second negative switch element that act synchronously; the positive fuse is connected to the positive path, and the first positive switch element and the second positive switch element are connected to the positive path in parallel to control the on-off of the positive path, and the pre-charging resistor is connected in series with the first positive switch element; the negative fuse and the shunt are connected in series to the negative path, and the first negative switch element and the second negative switch element are connected to the negative path in parallel to control the on-off of the negative path; the battery cluster control module is respectively connected to the shunt, the combined pre-charging module and the energy storage system signal. By adopting a combined pre-charging module in the combined pre-charging circuit of the energy storage high-voltage box, compared with the traditional control circuit using three contactors plus a DC isolating switch, the linkage and coordination problems between multiple contactors in the traditional circuit are reduced, which can greatly reduce the use of electrical equipment and save material costs; the number of circuit action devices is reduced, and the failure rate of the energy storage high-voltage box can be reduced while ensuring the normal operation of the circuit, and the overall performance stability of the circuit is significantly improved, which helps to reduce circuit anomalies caused by contactor failure or malfunction, thereby improving the overall operating efficiency of the energy storage high-voltage box; by adopting a combined pre-charging module, compared with the traditional circuit that needs to reserve space for four electrical components, the use space of the energy storage high-voltage box can be greatly saved; and the power-on and power-off operations of the energy storage high-voltage box can be completed by controlling the pre-charging switch group and the main switch group through the battery cluster control module, making the control logic more concise.

[0068] 2. A combined pre-charging circuit control method of an energy storage high-voltage box disclosed in the present invention is applied to the combined pre-charging circuit of the energy storage high-voltage box as described above. The battery cluster control module controls the closing and disconnection of the combined pre-charging module according to the power-on and power-off processes of the energy storage high-voltage box to realize the power-on and power-off of the energy storage high-voltage box. The power-on process includes the following steps: S101, power supply test of the energy storage high-voltage box, and electrical performance test of each battery in the battery cluster, and in the initial state, the pre-charging switch group and the main switch group are both in the disconnected state; S102, the pre-charging switch The group performs adhesion detection, and after the adhesion detection is normal, the pre-charge switch group is closed; S103, pre-charge is performed; S104, after the pre-charge is completed, the battery cluster control module controls the main switch group to close; S105, the pre-charge switch group is disconnected to complete the power-on of the energy storage high-voltage box; the power-off process includes the following steps: S201, stop the operation of the energy storage end, and power off the energy storage high-voltage box; S202, the battery cluster control module receives the power-off instruction, disconnects the main switch group, and determines whether it is disconnected normally; S203, after the main switch group is disconnected normally, the power-off of the energy storage high-voltage box is completed. By performing power supply tests and battery performance tests during the power-on process, subsequent operations are ensured to be performed only after the system is in a safe state, thus avoiding safety issues caused by equipment failure or battery abnormality; the adhesion detection of the pre-charging switch group ensures that the switch state is normal before closing, thus avoiding short circuits or failures caused by switch adhesion; during the power-off process, the operation of the energy storage end is stopped first, and then the power-off operation is performed, thus ensuring the safety of the system during power-off; the pre-charging process helps to start the system smoothly, thus avoiding energy loss and battery damage caused by direct access to large currents, and by precisely controlling the switch action, unnecessary energy consumption is reduced, thus improving the energy efficiency performance of the system; and the control method can be adjusted and optimized according to actual needs to adapt to different application scenarios and battery cluster types. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 This is a schematic diagram of the structure of a combined pre-charging circuit of an energy storage high-voltage box disclosed in the present invention.

[0070] Figure 2 It is a power-on process flow chart of a combined pre-charging circuit control method of an energy storage high-voltage box described in the present disclosure;

[0071] Figure 3 It is a flow chart of the power-off process of a combined pre-charging circuit control method of an energy storage high-voltage box described in the present invention.

[0072] Description of reference numerals:

[0073] 10-Combined pre-charge module;

[0074] 20-battery cluster control module;

[0075] 30-Energy storage high-voltage box;

[0076] FU1-positive fuse;

[0077] FU2-negative fuse;

[0078] RS-shunt;

[0079] R-pre-charge resistance;

[0080] K1-precharge switch group;

[0081] K2- Main switch group. DETAILED DESCRIPTION

[0082] like Figure 1 - Figure 3 As shown, a combined pre-charging circuit of an energy storage high-voltage box disclosed in the present disclosure is used to establish an electrical connection between a battery cluster and an energy storage system, wherein the positive electrode of the battery cluster is connected to the positive electrode of the energy storage system through a positive electrode path, and the negative electrode of the battery cluster is connected to the negative electrode of the energy storage system through a negative electrode path. The combined pre-charging circuit includes a positive electrode fuse FU1, a negative electrode fuse FU2, a shunt RS, a pre-charging resistor R, a combined pre-charging module 10, and a battery cluster control module 20;

[0083] The combined pre-charging module 10 includes a pre-charging switch group K1 and a main switch group K2, wherein the pre-charging switch group K1 includes a first positive switch element and a first negative switch element that act synchronously, and the main switch group K2 includes a second positive switch element and a second negative switch element that act synchronously;

[0084] The positive electrode fuse FU1 is connected to the positive electrode path, the first positive electrode switch element and the second positive electrode switch element are connected to the positive electrode path, and are used to control the on and off of the positive electrode path, and the pre-charging resistor R is connected in series with the first positive electrode switch element;

[0085] The negative electrode fuse FU2 and the shunt RS are connected in series to the negative electrode path, and the first negative electrode switch element and the second negative electrode switch element are connected to the negative electrode path in parallel to control the on and off of the negative electrode path;

[0086] Specifically, the circuit with the pre-charging switch group K1 is the pre-charging circuit, and the circuit with the main switch group K2 is the main circuit;

[0087] The battery cluster control module 20 is respectively connected to the shunt RS, the combined pre-charging module 10 and the energy storage system signal; the energy storage system includes an energy storage converter and a system cabinet; the battery cluster control module 20 is used to control the closing and opening of the switch in the combined pre-charging module 10, and to collect voltage data and current data;

[0088] By adopting a combined pre-charging module 10 in the pre-charging circuit, compared with the traditional control circuit using three contactors plus a DC isolating switch, the linkage and coordination problems between multiple contactors in the traditional circuit are reduced, which can greatly reduce the use of electrical equipment and save material costs; the number of circuit action devices is reduced, and the failure rate of the energy storage high-voltage box 30 can be reduced while ensuring the normal operation of the circuit, and the overall performance stability of the circuit is significantly improved, which helps to reduce circuit anomalies caused by contactor failure or malfunction, thereby improving the overall operating efficiency of the energy storage high-voltage box 30; by adopting a combined pre-charging module 10, compared with the traditional circuit that needs to reserve space for four electrical components, the use space of the energy storage high-voltage box can be greatly saved; and the power-on and power-off operations of the energy storage high-voltage box 30 can be completed by controlling the pre-charging switch group K1 and the main switch group K2 through the battery cluster control module 20, making the control logic more concise.

[0089] A combined pre-charging circuit control method for an energy storage high-voltage box is applied to the combined pre-charging circuit of the energy storage high-voltage box as described above. The battery cluster control module 20 controls the closing and opening of the combined pre-charging module 10 according to the power-on and power-off processes of the energy storage high-voltage box 30 to realize the power-on and power-off of the energy storage high-voltage box 30.

[0090] Furthermore, in this embodiment, the power-on process includes the following steps:

[0091] S101, perform a power supply test on the energy storage high-voltage box 30, and perform an electrical performance test on each battery in the battery cluster, and in the initial state, the pre-charge switch group K1 and the main switch group K2 are both in the disconnected state;

[0092] S102, performing adhesion detection on the pre-filling switch group K1, and closing the pre-filling switch group K1 after the adhesion detection is normal;

[0093] S103, pre-charging;

[0094] S104, after the pre-charging is completed, the battery cluster control module 20 controls the main switch group K2 to close;

[0095] S105 , disconnect the pre-charging switch group K1 to complete the power-on of the energy storage high-voltage box 30 .

[0096] Furthermore, in this embodiment, in step S101, the power supply test specifically includes:

[0097] Power supply test includes insulation performance test and circuit performance test;

[0098] Insulation performance testing includes the following steps:

[0099] Get the total voltage U of the battery cluster Z, the insulation resistance value R1 between the positive electrode of the battery cluster and the external exposed conductive part, and the insulation resistance value R2 between the negative electrode of the battery cluster and the external exposed conductive part;

[0100] If R1>1000*U Z And R2>1000*U Z , the insulation performance meets the requirements, and the circuit performance test is carried out;

[0101] If R1>1000*U Z And R2≤1000*U Z , the insulation performance does not meet the requirements, an alarm message is issued, and the insulation performance between the negative electrode of the battery cluster and the external exposed conductive part does not meet the requirements;

[0102] If R1≤1000*U Z And R2>1000*U Z , the insulation performance does not meet the requirements, an alarm message is issued, and the insulation performance between the positive electrode of the battery cluster and the external exposed conductive part does not meet the requirements;

[0103] If R1≤1000*U Z And R2≤1000*U Z , the insulation performance does not meet the requirements, an alarm message is issued, and the insulation performance between the positive electrode of the battery cluster and the external exposed conductive part, and between the negative electrode of the battery cluster and the external exposed conductive part do not meet the requirements;

[0104] Circuit performance testing includes the following steps:

[0105] Get the voltage value U of the circuit S , current value I S , Ambient temperature value W H , and the surface temperature value W of the energy storage high-voltage box 30 C , and calculate the circuit performance coefficient E according to the following formula S :

[0106]

[0107] Among them, U L is the theoretical initial voltage value; △U Lmax is the theoretical voltage difference; I L is the theoretical initial current value; △I Lmax is the theoretical current difference; W LCmax is the theoretical maximum surface temperature of the energy storage high-voltage box 30; a1, a2 and a3 are all weight coefficients, and satisfy a1+a2+a3=1;

[0108] If 0.9≤E SIf it is ≤ 1.1, the circuit performance test is qualified, and it is determined that the power supply test passes;

[0109] If E S <0.9 or E S >1.1, the circuit performance test is unqualified, an alarm message is sent, and it is determined that the power supply test fails;

[0110] Examples are as follows:

[0111] Insulation performance test:

[0112] The total voltage U of the battery cluster Z = 1500V, the insulation resistance value R1 between the positive electrode of the battery cluster and the externally exposed conductive part = 1600kΩ = 1600000Ω, and the insulation resistance value R2 between the negative electrode of the battery cluster and the externally exposed conductive part = 1550kΩ = 1550000Ω;

[0113] Then R1 = <1600000> 1000 * 1500 and R2 = <1550000> 1000 * 1500, so the insulation performance meets the requirements, and the circuit performance test is carried out;

[0114] Circuit performance test:

[0115] The voltage value U of the loop S = 55V, the current value I S = 75A, the ambient temperature value W H = 25°C, and the surface temperature value W of the energy storage high-voltage box 30 C = 28°C, a1 = 0.3, a2 = 0.3, a3 = 0.4;

[0116] U L = 60V, △U Lmax = 5V, I L = 80A, △I Lmax = 5A, W LCmax = 50°C;

[0117]

[0118] So E S = 1.08 ≤ 1.1, satisfying 0.9 ≤ E S ≤ 1.1, the circuit performance test is qualified, and it is determined that the power supply test passes.

[0119] Furthermore, in this embodiment, in step S101, the electrical performance test includes the following steps:

[0120] The electrical performance test includes calculating the actual state of charge value SOC and the actual state of health value SOH of a single battery, and determining whether the electrical performance test passes according to the calculated results;

[0121] Collect the initial charge value SOC0 of a single battery in the battery cluster, the battery charge and discharge cycle time t, the current value I within a charge and discharge cycle time t, the total capacity C of a single battery, and the actual capacity value Q of a single battery d , get the theoretical battery state of charge value SOC L And the theoretical battery health status SOH L ;

[0122] Divide a charge and discharge cycle time t into M time periods according to equal time intervals △t, and obtain the average current value of each time period Calculate the actual battery state of charge value SOC and the actual battery health state value SOH:

[0123]

[0124] Among them, Q n is the theoretical initial rated capacity value of a single battery; △t<t;

[0125] If SOC=[0.85*SOC L , 1.15*SOC L ] and SOH=[0.90*SOH L , 1.10*SOH L ], the electrical performance test is judged to have passed;

[0126] If SOC≠[0.85*SOC L , 1.15*SOC L ] and SOH=[0.90*SOH L , 1.10*SOH L ], the electrical performance test is judged to be unsuccessful, an alarm message is issued, and abnormal information of the actual battery state of charge value SOC is output;

[0127] If SOC=[0.85*SOC L , 1.15*SOC L ] and SOH≠[0.90*SOH L , 1.10*SOH L ], the electrical performance test is judged to be unsuccessful, an alarm message is issued, and the actual battery health status value SOH abnormal information is output;

[0128] If SOC≠[0.85*SOC L , 1.15*SOC L ] and SOH≠[0.90*SOH L , 1.10*SOH L], the electrical performance test is judged to be unsuccessful, an alarm message is issued, and abnormal information of the actual battery state of charge value SOC and abnormal information of the actual battery health state value SOH are output;

[0129] Here is an example:

[0130] The initial charge value SOC0 of a single battery is 94%, and a charge and discharge cycle time t = 10min is divided into 5 time periods according to the equal time interval △t = 2min, and the average current value of each time period is obtained.

[0131]

[0132] The total capacity of a single battery is C = 400Ah, and the actual capacity value of a single battery is Q d =380Ah, get the theoretical battery state of charge value SOC L =95%, theoretical battery health status value SOH L =90%, the theoretical initial rated capacity of a single battery is Q n =400Ah;

[0133]

[0134] Therefore, 1.15*95%=109.25%>SOC=82%>0.85*95%=80.75%, so SOC=[0.85*SOC L , 1.15*SOC L ];

[0135] 1.10*90%=99%>SOH=95%>0.90*90%=81%, so SOH=[0.90*SOH L , 1.10*SOH L ];

[0136] In summary, SOC = [0.85*SOC L , 1.15*SOC L ] and SOH = [0.90*SOH L , 1.10*SOH L ], the electrical performance test is judged to have passed.

[0137] Furthermore, in this embodiment, step S102 specifically includes:

[0138] After the power supply test and electrical performance test are passed, the pre-charge switch group K1 is subjected to adhesion detection;

[0139] After the adhesion detection is passed, the battery cluster control module 20 sends a pre-charge instruction and closes the pre-charge switch group K1;

[0140] Adhesion testing includes:

[0141] The battery cluster control module 20 sends a command to close and disconnect the pre-charging switch group K1. First, the battery cluster control module 20 sends a command to close the pre-charging switch group K1. After receiving the command to close the pre-charging switch group K1, the current value I at the position of the pre-charging switch group K1 is detected. B1 and the resistance value R B1 ;

[0142] If I B1 ≠0 and R B1 ≠0, it is judged that the pre-charge switch group K1 is closed correctly, and subsequent operations are performed;

[0143] If I B1 =0 and / or R B1 =0, it is judged that the pre-charge switch group K1 is not closed correctly, an alarm message is issued, and maintenance is carried out;

[0144] After confirming that the pre-charging switch group K1 is correctly closed, the battery cluster control module 20 sends an instruction to disconnect the pre-charging switch group K1. After receiving the instruction to disconnect the pre-charging switch group K1, the current value I at the position of the pre-charging switch group K1 is detected. B2 and the resistance value R B2 ;

[0145] If I B2 = 0 and R B2 =∞, it is judged that the pre-charge switch group K1 is correctly disconnected, and the adhesion test is judged to have passed;

[0146] If I B2 ≠0 and / or R B2 ≠∞, it is judged that the pre-charge switch group K1 is not disconnected correctly, an alarm message is issued, and maintenance is carried out.

[0147] Furthermore, in this embodiment, step S103 specifically includes:

[0148] Set the pre-charge time T Y , during the pre-charge time T Y Execute the pre-charging process internally;

[0149] After the pre-charging process is completed, measure the total voltage U between the battery cluster and the main switch group K2. Z , and judge whether the pre-charging process meets the pre-charging requirements;

[0150] If U Z ≥90%*U CZ , it is determined that the pre-charging requirements are met, and the battery cluster control module 20 sends a pre-charging success instruction to complete the pre-charging;

[0151] If U Z<90%*U CZ , it is judged that the pre-charging requirement is not met, a new pre-charging time is reset, and pre-charging is performed according to the new pre-charging time until the pre-charging requirement is met;

[0152] Among them, U CZ Indicates the total voltage value of the battery cluster;

[0153] Here is an example:

[0154] Set the pre-charge time T Y = 3h, the pre-charging process is carried out within 3h. After the pre-charging process is completed, the total voltage value U of the circuit between the battery cluster and the main switch group K2 is measured. Z =55V;

[0155] U CZ =60V;

[0156] Then U Z =55>90%*U CZ =90%*60, it is determined that the pre-charging requirement is met, and the battery cluster control module 20 sends a pre-charging success instruction to complete the pre-charging.

[0157] Furthermore, in this embodiment, step S105 specifically includes:

[0158] Set the waiting time T D After the battery cluster control module 20 controls the main switch group K2 to close, the waiting time T D After that, the current value I at both ends of the pre-charge switch group K1 is detected. YC and the current value I across the main switch group K2 ZC , judging the normality of the circuit connection state, and judging the normality of the circuit connection state as completing the power-on of the energy storage high-voltage box 30;

[0159] If I YC =0 and I ZC ≠0, it is judged that the circuit connection state is normal, and the power-on completion information of the energy storage high-voltage box 30 is output;

[0160] If I YC ≠0 and I ZC ≠0, the circuit connection status is judged to be abnormal, an alarm message is issued, and the pre-charge switch group K1 is not disconnected;

[0161] If I YC =0 and I ZC =0, the circuit connection status is judged to be abnormal, an alarm message is issued, and the main switch group K2 is not connected information is output;

[0162] If I YC ≠0 and I ZC=0, the circuit connection state is judged to be abnormal, an alarm message is issued, and the pre-charge switch group K1 is not disconnected and the main switch group K2 is not connected is output;

[0163] Here is an example:

[0164] Set the waiting time T D = 5min, after the battery cluster control module 20 controls the main switch group K2 to close, it waits for 5min and detects that I YC =0A and I ZC =20A;

[0165] Then I YC =0 and I ZC ≠0, it is judged that the circuit connection state is normal, and the power-on completion information of the energy storage high-voltage box 30 is output.

[0166] Furthermore, in this embodiment, the power-off process includes the following steps:

[0167] S201, stopping the operation of the energy storage end and powering off the energy storage high-voltage box 30;

[0168] S202, the battery cluster control module 20 receives the power-off instruction, disconnects the main switch group K2, and determines whether it is disconnected normally;

[0169] S203, after the main switch group K2 is normally disconnected, the energy storage high-voltage box 30 is powered off.

[0170] Furthermore, in this embodiment, step S202 specifically includes:

[0171] The battery cluster control module 20 receives the power-off instruction, disconnects the main switch group K2, and determines whether the main switch group K2 is disconnected normally. The determination method is as follows:

[0172] Set the detection period T J , the detection period T J Divide N detection time points t into equal time intervals i (i=0,1,2…N), each detection time point t i Detect the voltage value U across the main switch group K2 Fi and current value I Fi (i=0,1,2…N), with t0 as the initial time, U detected at t0 F0 and I F0 are the initial detection voltage and current values ​​respectively, and the power-down coefficient K is calculated according to the following formula D :

[0173]

[0174] If I F0 = 0 and KD =0, it is judged that the main switch is normally disconnected;

[0175] If I F0 ≠0 or K D ≠0, it is judged that the main switch is not disconnected normally and an alarm message is issued;

[0176] After the main switch group K2 is disconnected normally, the current value at both ends should be 0, and the voltage value should be equal to the voltage provided by the battery cluster circuit and remain unchanged;

[0177] Here is an example:

[0178] Set the detection period T J = 10min, divided into N = 5 detection time points at equal time intervals t i (i=0,1,2…N), then at t0=0, U F0 =30V, I F0 =0A; t1 = 2min, U F1 =30V, I F1 =0A; t2 = 4min, U F2 =30V, I F2 =0A; t3 = 6min, U F3 =30V, I F3 =0A; t4 = 8min, U F4 =30V, I F4 =0A; t5 = 10min, U F5 =30V, I F5 =0A;

[0179] K D =[(U F1 -U F0 )+(U F2 -U F0 )+(U F3 -U F0 )+(U F4 -U F0 )+

[0180] (U F5 -U F0 )]+[(I F1 -I F0 )+(I F2 -I F0 )+(I F3 -I F0 )+(I F4 -I F0 )+(I F5 -I F0 )]=0

[0181] Therefore, I F0 = 0 and K D =0, it is judged that the main switch is normally disconnected.

[0182] In summary, by performing power supply test and battery performance test during the power-on process, it is ensured that the system is in a safe state before subsequent operations are performed, thus avoiding safety problems caused by equipment failure or battery abnormality; the adhesion detection of the pre-charging switch group K1 ensures that the switch state is normal before closing, thus avoiding short circuit or failure caused by switch adhesion; during the power-off process, the operation of the energy storage end is stopped first, and then the power-off operation is performed, thus ensuring the safety of the system during power-off; the pre-charging process helps to start the system smoothly, avoiding energy loss and battery damage caused by direct access to large current, and reducing unnecessary energy consumption and improving the energy efficiency performance of the system by precisely controlling the switch action; and the control method can be adjusted and optimized according to actual needs to adapt to different application scenarios and battery cluster types.

[0183] In the description of the present disclosure, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present disclosure.

[0184] For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of the present disclosure.

Claims

1. A combined pre-charging circuit of an energy storage high-voltage box, used to establish an electrical connection between a battery cluster and an energy storage system, wherein the positive electrode of the battery cluster is connected to the positive electrode of the energy storage system through a positive electrode path, and the negative electrode of the battery cluster is connected to the negative electrode of the energy storage system through a negative electrode path, characterized in that: The combined pre-charging circuit comprises a positive electrode fuse (FU1), a negative electrode fuse (FU2), a shunt (RS), a pre-charging resistor (R), a combined pre-charging module (10) and a battery cluster control module (20); The combined pre-charging module (10) comprises a pre-charging switch group (K1) and a main switch group (K2), wherein the pre-charging switch group (K1) comprises a first positive switch element and a first negative switch element that act synchronously, and the main switch group (K2) comprises a second positive switch element and a second negative switch element that act synchronously; The positive electrode fuse (FU1) is connected to the positive electrode path, the first positive electrode switch element and the second positive electrode switch element are connected to the positive electrode path, and are used to control the on and off of the positive electrode path, and the pre-charging resistor (R) is connected in series with the first positive electrode switch element; The negative electrode fuse (FU2) and the shunt (RS) are connected in series to the negative electrode path, and the first negative electrode switch element and the second negative electrode switch element are connected to the negative electrode path in parallel, so as to control the on and off of the negative electrode path; The battery cluster control module (20) is respectively connected to the current divider (RS), the combined pre-charging module (10) and the energy storage system by signals.

2. A combined pre-charging circuit control method for an energy storage high-voltage box, applied to the combined pre-charging circuit of the energy storage high-voltage box as claimed in claim 1, characterized in that: The battery cluster control module (20) controls the closing and opening of the combined pre-charging module (10) according to the power-on and power-off processes of the energy storage high-voltage box (30), so as to realize the power-on and power-off of the energy storage high-voltage box (30).

3. The combined pre-charging circuit control method of the energy storage high-voltage box according to claim 2, characterized in that: The power-on process includes the following steps: S101, performing a power supply test on the energy storage high-voltage box (30), and performing an electrical performance test on each battery in the battery cluster, and in an initial state, the pre-charging switch group (K1) and the main switch group (K2) are both in a disconnected state; S102, performing a sticking test on the pre-filling switch group (K1), and closing the pre-filling switch group (K1) after the sticking test is normal; S103, pre-charging; S104, after the pre-charging is completed, the battery cluster control module (20) controls the main switch group (K2) to close; S105, disconnecting the pre-charging switch group (K1) to complete powering on the energy storage high-voltage box (30).

4. The combined pre-charging circuit control method of the energy storage high-voltage box according to claim 3, characterized in that: In step S101, the power supply test specifically includes: The power supply test includes insulation performance testing and circuit performance testing; The insulation performance test comprises the following steps: Get the total voltage U of the battery cluster Z , the insulation resistance value R1 between the positive electrode of the battery cluster and the external exposed conductive part, and the insulation resistance value R2 between the negative electrode of the battery cluster and the external exposed conductive part; If R1>1000*U Z And R2>1000*U Z , the insulation performance meets the requirements, and the circuit performance test is performed; If R1>1000*U Z And R2≤1000*U Z , the insulation performance does not meet the requirements, an alarm message is issued, and an output is output that the insulation performance between the negative electrode of the battery cluster and the external exposed conductive part does not meet the requirements; If R1≤1000*U Z And R2>1000*U Z , the insulation performance does not meet the requirements, an alarm message is issued, and an output is output that the insulation performance between the positive electrode of the battery cluster and the external exposed conductive part does not meet the requirements; If R1≤1000*U Z And R2≤1000*U Z , the insulation performance does not meet the requirements, an alarm message is issued, and an output is output that the insulation performance between the positive electrode of the battery cluster and the external exposed conductive part, and between the negative electrode of the battery cluster and the external exposed conductive part both do not meet the requirements; The circuit performance detection comprises the following steps: Get the voltage value U of the circuit S , current value I S , Ambient temperature value W H , and the surface temperature value W of the energy storage high-voltage box (30) C , and calculate the circuit performance coefficient E according to the following formula S : Among them, U L is the theoretical initial voltage value; △U Lmax is the theoretical voltage difference; I L is the theoretical initial current value; △I Lmax is the theoretical current difference; W LCmax is the theoretical maximum temperature value of the surface of the energy storage high-voltage box (30); a1, a2 and a3 are all weight coefficients, and satisfy a1+a2+a3=1; If 0.9≤E S ≤1.1, the circuit performance test is qualified and the power supply test is judged to have passed; If E S <0.9 or E S >1.1, the circuit performance test fails, an alarm message is issued, and the power supply test is judged to have failed.

5. The combined pre-charging circuit control method of the energy storage high-voltage box according to claim 3, characterized in that: In step S101, the electrical performance test includes the following steps: The electrical performance test includes calculating an actual battery state of charge value SOC and an actual battery health state value SOH of a single battery, and judging whether the electrical performance test is passed according to the calculation results; Collect the initial charge value SOC0 of a single battery in the battery cluster, a charge and discharge cycle time t of the battery, the current value I within a charge and discharge cycle time t, the total capacity C of a single battery, and the actual capacity value Q of a single battery d , get the theoretical battery state of charge value SOC L And the theoretical battery health status SOH L ; Divide a charge and discharge cycle time t into M time periods according to equal time intervals △t, and obtain the average current value I in each time period n (n=1, 2...M), calculate the actual battery state of charge value SOC and the actual battery health state value SOH: Among them, Q n is the theoretical initial rated capacity value of a single battery; △t<t; If SOC=[0.85*SOC L , 1.15*SOC L ] and SOH=[0.90*SOH L , 1.10*SOH L ], it is judged that the electrical performance test has passed; If SOC≠[0.85*SOC L , 1.15*SOC L ] and SOH=[0.90*SOH L , 1.10*SOH L ], it is determined that the electrical performance test fails, an alarm message is issued, and abnormal information of the actual battery state of charge value SOC is output; If SOC=[0.85*SOC L , 1.15*SOC L ] and SOH≠[0.90*SOH L , 1.10*SOH L ], it is determined that the electrical performance test fails, an alarm message is issued, and the actual battery health status value SOH abnormal information is output; If SOC≠[0.85*SOC L , 1.15*SOC L ] and SOH≠[0.90*SOH L , 1.10*SOH L ], it is judged that the electrical performance test fails, an alarm message is issued, and the actual battery power state value SOC abnormal information and the actual battery health state value SOH abnormal information are output.

6. The combined pre-charging circuit control method of the energy storage high-voltage box according to claim 3, characterized in that: The step S102 specifically includes: After both the power supply test and the electrical performance test are passed, performing adhesion detection on the pre-charging switch group (K1); After the adhesion detection is passed, the battery cluster control module (20) sends a pre-charging instruction and closes the pre-charging switch group (K1).

7. The combined pre-charging circuit control method of the energy storage high-voltage box according to claim 3, characterized in that: The step S103 specifically includes: Set the pre-charge time T Y , during the precharge time T Y Execute the pre-charging process internally; After the pre-charging process is completed, the total voltage value U of the circuit between the battery cluster and the main switch group (K2) is measured. Z , and judging whether the pre-charging process meets the pre-charging requirements; If U Z ≥90%*U CZ , it is determined that the pre-charging requirement is met, and the battery cluster control module (20) sends a pre-charging success instruction to complete the pre-charging; If U Z <90%*U CZ , it is judged that the pre-charging requirement is not met, a new pre-charging time is reset, and pre-charging is performed according to the new pre-charging time until the pre-charging requirement is met; Among them, U CZ Indicates the total voltage value of the battery cluster.

8. The combined pre-charging circuit control method of the energy storage high-voltage box according to claim 3 is characterized in that: The step S105 specifically includes: Set the waiting time T D After the battery cluster control module (20) controls the main switch group (K2) to close, the waiting time T D After that, the current value I at both ends of the pre-charging switch group (K1) is detected. YC and the current value I at both ends of the main switch group (K2) ZC , judging the normality of the circuit connection state, and judging that the circuit connection state is normal is used as the completion of powering on the energy storage high-voltage box (30); If I YC =0 and I ZC ≠0, it is judged that the circuit connection state is normal, and the power-on completion information of the energy storage high-voltage box (30) is output; If I YC ≠0 and I ZC ≠0, it is judged that the circuit connection state is abnormal, an alarm message is issued, and information that the pre-charging switch group (K1) is not disconnected is output; If I YC =0 and I ZC =0, the circuit connection state is judged to be abnormal, an alarm message is issued, and the main switch group (K2) is not connected information is output; If I YC ≠0 and I ZC =0, the circuit connection state is judged to be abnormal, an alarm message is issued, and information that the pre-charging switch group (K1) is not disconnected and information that the main switch group (K2) is not connected is output.

9. The combined pre-charging circuit control method of the energy storage high-voltage box according to claim 2, characterized in that: The power-off process includes the following steps: S201, stopping the operation of the energy storage end and powering off the energy storage high-voltage box (30); S202, the battery cluster control module (20) receives a power-off instruction, disconnects the main switch group (K2), and determines whether the disconnection is normal; S203: After the main switch group (K2) is normally disconnected, the energy storage high-voltage box (30) is powered off.

10. The combined pre-charging circuit control method of the energy storage high-voltage box according to claim 9, characterized in that: The step S202 specifically includes: The battery cluster control module (20) receives a power-off instruction, disconnects the main switch group (K2), and determines whether the main switch group (K2) is disconnected normally, and the determination method is as follows: Set the detection period T J , the detection period T J Divide N detection time points t into equal time intervals i (i=0,1,2…N), each detection time point t i Detect the voltage value U across the main switch group (K2) Fi and current value I Fi (i=0,1,2…N), with t0 as the initial time, U detected at t0 F0 and I F0 are the initial detection voltage and current values ​​respectively, and the power-down coefficient K is calculated according to the following formula D : If I F0 = 0 and K D =0, it is judged that the main switch is normally disconnected; If I F0 ≠0 or K D ≠0, it is determined that the main switch is not disconnected normally and an alarm message is issued.

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