A high voltage battery cluster control system and method

Abstract

The application discloses a high-voltage battery cluster and cluster control system and method, the system comprises battery series connection groups, each battery group is managed and controlled by a battery group master control module; the battery group master control module comprises a temperature sampling circuit, a first voltage and current sampling circuit, a DCDC circuit, a switch matrix circuit and a CAN bus communication circuit. The DCDC circuit is connected in series with the first battery group to form a second battery group, and a plurality of second battery groups are connected in series to form a battery cluster; each battery cluster is managed and controlled by a battery cluster master control module, and the battery cluster master control module controls a plurality of battery group master control modules in the next level to perform balancing and voltage stabilizing operations; the upper level of the battery cluster master control module is provided with an energy storage system master control module, state information of each battery cluster is acquired, and the battery cluster master control module in the next level is controlled to perform clustering. The application reduces the circulating current influence between battery clusters, avoids the risk of overheating or damage of the battery cluster, and prolongs the service life of the battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage battery, in particular to a high-voltage battery cluster parallel cluster control system and method. BACKGROUND

[0002] At present, the energy storage system generally uses the method of connecting multiple batteries in series to form a battery pack, connecting a certain number of battery packs to form a battery cluster, and finally connecting multiple battery clusters in parallel to improve the capacity of the energy storage system. However, due to the inconsistency of the battery, there will be a voltage difference between the battery clusters when they are connected in parallel. The battery cluster with high voltage will charge the battery cluster with low voltage, thereby generating inter-cluster circulating current. The inter-cluster circulating current will increase the energy loss of the battery and reduce the system efficiency. When the circulating current is too large, it will also affect the service life of the battery, and more seriously, it will burn the circuit and cause safety accidents.

[0003] The existing technology mainly uses a pre-charging resistor to reduce the inter-cluster circulating current. The main function of the pre-charging resistor is to pre-charge the battery cluster through a resistor before connecting the battery clusters in parallel, so that the voltage gradually approaches the voltage of other battery clusters, thereby reducing the impact current and circulating current when connecting in parallel. However, the pre-charging process requires a certain amount of time, especially when the voltage difference between the battery clusters is large. This may prolong the system startup and parallel connection time, affecting the rapid response capability of the system. At the same time, during the pre-charging process, the current passing through the pre-charging resistor will generate heat, resulting in energy loss. Especially in a high-power system, the energy loss can be considerable. SUMMARY

[0004] In view of the above problems, the present application provides a high-voltage battery cluster parallel cluster control system and method, which reduces the influence of circulating current when connecting the battery clusters in parallel and realizes safe and reliable parallel connection of the battery clusters.

[0005] In order to solve the above technical problems, the present application provides a high-voltage battery cluster parallel cluster control system, which comprises: a plurality of batteries connected in series to form a battery pack, and each battery pack is managed and controlled by a battery pack master control module BMU. The battery pack master control module BMU mainly includes a temperature sampling circuit, a first voltage and current sampling circuit, a DCDC circuit, a switch matrix circuit and a CAN bus communication circuit; the battery pack master control module BMU takes an STM32 series or other series single-chip microcomputer as the main control chip.

[0006] The temperature sampling circuit includes a plurality of temperature sensors, each of which is arranged in the temperature-sensitive area of the battery. The temperature sensor is directly connected to the battery pack master control module BMU main control chip, and transmits the collected analog signal to the battery pack master control module BMU for analysis and processing after converting it into a digital signal.

[0007] The first voltage and current sampling circuit is composed of a high-precision voltage sensor and a current sensor, which is used to monitor the voltage and current changes of the battery unit in real time. The output terminals of the voltage sensor and the current sensor are connected to an analog-to-digital converter (ADC), and the ADC sends the data to the main control module for analysis and processing.

[0008] The DCDC circuit is connected in series with the first battery pack to form a second battery pack, and multiple second battery packs are connected in series to form a battery cluster. As a preferred embodiment, the low-voltage positive port of the DCDC circuit is connected to the positive electrode of the second battery pack, the low-voltage negative port is connected to the positive electrode of the first battery pack, the high-voltage positive port is connected to the positive electrode of the first battery pack, and the high-voltage negative port is connected to the negative electrode of the first battery pack.

[0009] The switch matrix circuit is combined with the DCDC circuit, which is used for active balancing within the battery pack before clustering. After balancing, the switch matrix circuit is switched, and the DCDC circuit is switched to a voltage stabilizing mode, so that the second battery pack outputs a constant voltage. As a preferred embodiment, each battery in the battery pack is divided into odd-numbered batteries and even-numbered batteries according to the order. The positive electrode of the odd-numbered battery (i.e. the negative electrode of the even-numbered battery) is connected to the polarity switches S3 and S4 through a switch, and the negative electrode of the odd-numbered battery (i.e. the positive electrode of the even-numbered battery) is connected to the polarity switches S1 and S2 through a switch. The polarity switches S1 and S3, S2 and S4 are connected to the low-voltage positive port and the low-voltage negative port of the DCDC circuit, respectively.

[0010] The CAN bus communication circuit is directly connected to the data interface of the main control chip, equipped with a CAN controller and a physical layer transceiver, and realizes the bidirectional data exchange between the battery pack main control module BMU and the upper battery cluster main control module BCMU.

[0011] Furthermore, a number of battery packs are connected in series to form a battery cluster, and each battery cluster is managed and controlled by a battery cluster main control module BCMU. The battery cluster main control module BCMU controls multiple battery pack main control modules BMU to perform balancing and voltage stabilizing operations. The battery cluster main control module BCMU mainly includes a contactor control circuit, a second voltage and current sampling circuit, an insulation resistance detection circuit, and a CAN bus communication circuit; the battery cluster main control module BCMU uses an STM32 series or other series single-chip microcomputer as the main control chip.

[0012] The second voltage and current sampling circuit, as a preferred embodiment, acquires voltage and current information through a Hall voltage sensor and a Hall current sensor to monitor the safety state of the battery cluster. The output terminals of the Hall voltage sensor and the Hall current sensor are connected to an ADC, and the ADC sends the data to the battery cluster main control module BCMU for analysis and processing. The battery cluster voltage needs to be sampled before clustering to determine whether it meets the clustering conditions;

[0013] The insulation resistance detection circuit is used for detecting the positive and negative insulation resistances of the battery cluster and outputting the detection results to the battery cluster master module BCMU.

[0014] The contactor control circuit is composed of a fuse, a circuit breaker and positive and negative contactors. The high-voltage positive pole of the battery cluster is connected to the positive contactor, the positive contactor is connected to the fuse, the fuse is connected to the circuit breaker, and the circuit breaker is directly connected to the positive pole of the DC bus.

[0015] The CAN bus communication circuit is equipped with a CAN controller and a physical layer transceiver to realize the bidirectional data exchange between the battery pack master module BMU and the battery cluster master module BCMU and between the battery cluster master module BCMU and the energy storage system master module BSMU.

[0016] The battery pack master module BMU, the battery cluster master module BCMU and the energy storage system master module BSMU take a single-chip microcomputer as the main control chip.

[0017] Further, an energy storage system master module BSMU is arranged at the upper level of the multiple battery cluster master modules BCMU, which acquires the state information of each battery cluster and controls the multiple battery cluster master modules BCMU at the lower level to perform the clustering operation through the CAN bus communication circuit.

[0018] Correspondingly, the application also provides a high-voltage battery cluster clustering control method applied to the high-voltage battery cluster clustering control system.

[0019] Step one, the energy storage system master module BSMU initiates a data upload instruction to the battery cluster master modules BCMU1-BCMUn through the CAN bus communication circuit.

[0020] Step two, the battery cluster master module BCMUi acquires the battery cluster voltage and the positive and negative insulation resistances of the battery cluster through the battery cluster voltage and current sampling circuit and the insulation resistance detection circuit respectively according to the data upload instruction and uploads the corresponding information to the energy storage system master module BSMU through the CAN bus communication circuit.

[0021] Step three, the energy storage system master module BSMU selects the battery clusters meeting the clustering condition according to the battery cluster voltage and the positive and negative insulation resistance information uploaded by the battery cluster master modules BCMU1-BCMUn and sends a same battery pack voltage reference V to each battery cluster master module BCMU meeting the clustering condition.

[0022] Step four, the battery cluster master control module BCMUi meeting the clustering condition controls the subordinate multiple battery master control modules BMU to perform equalization control through the CAN bus. After equalization is completed, the battery master control module BMU is controlled to switch to the voltage stabilization mode, so that each battery group is stabilized to the battery group voltage reference V.

[0023] Step five, after the battery cluster master control module BCMUi detects that each battery master control module BMU reaches the voltage reference V, the corresponding battery cluster is incorporated into the DC bus through the contactor control circuit.

[0024] Further, the control method of the battery cluster master control module BCMU on the subordinate multiple battery master control modules BMU in the above step four comprises the following steps:

[0025] Step 4.1, the battery cluster master control module BCMU initiates a request data upload instruction to the battery master control modules BMU1~BMUn through the CAN bus communication circuit.

[0026] Step 4.2, the battery cluster master control module BCMU calculates the SOC of each battery according to the voltage and current data uploaded by the battery master control module BMUi. After the calculation is completed, an equalization command is sent to the battery master control module BMUi to control it to perform equalization on the battery not within the preset SOC threshold.

[0027] Step 4.3, the battery master control module BMUi controls the DCDC circuit and the switch matrix circuit to perform equalization on the corresponding battery, and returns new voltage and current data to the battery cluster master control module BCMU to perform iterative update of the SOC.

[0028] Step 4.4, the battery cluster master control module BCMU calculates that a certain battery group has been equalized, and then sends a command to control it to switch to the voltage stabilization mode, so that the output voltage is stabilized at the voltage reference V.

[0029] Step 4.5, the battery cluster master control module BCMU detects that each battery group switches to the voltage stabilization mode and the output voltage is stabilized at the voltage reference V, and performs the clustering operation.

[0030] The present application has the following characteristics and beneficial effects:

[0031] The application obtains the cluster voltage and the insulation resistance size of the battery cluster in real time through the CAN bus before clustering, and ensures the safety and reliability of the clustered battery cluster. Each battery pack realizes switching between the equalization and voltage stabilization modes through the DCDC circuit and the switch matrix circuit. Before clustering, each battery is equalized according to the SOC, so as to ensure the consistency of the SOC of each battery in the battery cluster, improve the endurance time and the cycle life of the battery. After equalization, the voltage stabilization mode is switched, so that the output voltage of each battery cluster connected to the bus is consistent, thereby reducing the circulating current influence between the battery clusters, avoiding the risk of overheating or damage of the battery cluster, prolonging the service life of the battery, and enhancing the stability and reliability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor under the premise of the drawings.

[0033] Figure 1 is the circuit principle diagram of the high-voltage battery cluster clustering control system of the present application;

[0034] Figure 2 is the circuit principle diagram of a single battery pack of the present application;

[0035] Figure 3 is the logic control diagram of the battery cluster clustering of the present application;

[0036] Figure 4 is the circuit principle diagram of the insulation resistance sampling circuit involved in the present application;

[0037] Figure 5 is the equalization result diagram of the battery pack master control module of the present application;

[0038] Explanation of reference signs:

[0039] Energy storage system master control module BSMU; battery cluster master control module BCMU; battery pack master control module BMU; positive contactor KM1; negative contactor KM2; switch matrix switch K1-Kn; polarity switch S1-S4; positive insulation resistance RP; negative insulation resistance RN; resistance RSP; resistance RSN; resistance RAMC; switch SP; switch SN; isolation operational amplifier OP1; operational amplifier OP2; voltage source U1. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, so that the advantages and characteristics of the present application can be more easily understood by those skilled in the art, and the protection scope of the present application can be more clearly and definitely defined.

[0041] The high-voltage battery cluster control system provided in the present example is shown in Figure 2 The battery cluster control system provided in the present example is shown in

[0042] The temperature sampling circuit comprises a plurality of temperature sensors, each of which is arranged in a temperature-sensitive area of a battery. The temperature sensors are directly connected to the main control chip, and transmit the collected analog signals to the main control module for analysis and processing after converting the collected analog signals into digital signals.

[0043] The first voltage and current sampling circuit is composed of a high-precision voltage sensor and a current sensor, and is used to monitor the voltage and current changes of the battery unit in real time. The output end of the sensor is connected to an ADC, and the ADC transmits data to the main control module for analysis and processing.

[0044] The DCDC circuit is connected in series with the first battery cluster to form a second battery cluster, and a plurality of second battery clusters are connected in series to form a battery cluster. As a preferred embodiment, the low-voltage positive port of the DCDC circuit is connected to the positive pole of the second battery cluster, the low-voltage negative port is connected to the positive pole of the first battery cluster, the high-voltage positive port is connected to the positive pole of the first battery cluster, and the high-voltage negative port is connected to the negative pole of the first battery cluster.

[0045] The switch matrix circuit is combined with the DCDC circuit, and is used for active balancing in the battery cluster before clustering. After balancing, the switch matrix circuit is switched, and the DCDC circuit is switched to a voltage stabilizing mode, so that the second battery cluster outputs a constant voltage.

[0046] Specifically, as shown in Figure 2 Each battery in the battery cluster is divided into odd-numbered batteries and even-numbered batteries according to the order. The positive poles of the odd-numbered batteries (i.e. the negative poles of the even-numbered batteries) are connected to polarity switches S3 and S4 through a switch, and the negative poles of the odd-numbered batteries (i.e. the positive poles of the even-numbered batteries) are connected to polarity switches S1 and S2 through a switch. The polarity switches S1 and S3, and S2 and S4 are connected to the low-voltage positive port and the low-voltage negative port of the DCDC circuit, respectively.

[0047] When the SOC of the nth battery in the battery pack is not within the preset threshold range, the battery pack master module BMU first controls the switches kn and kn+1 in the switch matrix circuit to open, then controls two of the polarity switches S1-S4 to open (only one of S1 and S2 can be open at the same time, and only one of S3 and S4 can be open at the same time), and finally controls the DCDC circuit to start forward equalization or reverse equalization.

[0048] After equalization is completed, the battery pack master module BMU switches to a voltage stabilization mode. In the voltage stabilization mode, the switches in the switch matrix circuit and the polarity switches are all disconnected, and the battery pack master module BMU controls the DCDC circuit to work with the difference between the voltage of the current battery pack and the preset battery pack voltage reference as a feedback, so that the battery pack voltage is stabilized at the preset battery pack voltage reference.

[0049] The CAN bus communication circuit is directly connected to the data interface of the master chip, is equipped with a CAN controller and a physical layer transceiver, and realizes bidirectional data exchange between the battery pack master module BMU and the upper-level battery cluster master module BCMU.

[0050] Further, as shown in Figure 1 A plurality of battery packs are connected in series to form a battery cluster, and each battery cluster is managed and controlled by a battery cluster master module BCMU. The battery cluster master module BCMU controls a plurality of battery pack master modules BMU under it to perform equalization and voltage stabilization operations. The battery cluster master module BCMU mainly includes a contactor control circuit, a second voltage and current sampling circuit, an insulation resistance detection circuit, and a CAN bus communication circuit; and the battery cluster master module BCMU takes an STM32 series or other series single-chip microcomputer as a master chip.

[0051] The second voltage and current sampling circuit, as an optimization, acquires voltage and current information through a Hall voltage sensor and a Hall current sensor to monitor the safety state of the battery cluster. Before the battery cluster is connected in parallel, the voltage of the battery cluster needs to be sampled to determine whether the voltage meets the parallel connection condition;

[0052] Further, in this example, a Hall voltage sensor of model HNV-1000T is used, two HNV-1000Ts are connected in parallel with the battery cluster and the bus, and the results are output to the BCMU for data processing, so as to obtain the voltage data of the battery cluster; a Hall current sensor of model HNC-300LT is used in this example, and the HNC-300LT needs to be arranged with the DC bus passing through the sensor in parallel. The HNC-300LT outputs a constant current output, so a precision resistor is needed to convert the result into a voltage output and then output to the BCMU for data processing, so as to obtain the current data.

[0053] The insulation resistance detection circuit is used for detecting the positive insulation resistance and the negative insulation resistance of the battery cluster.

[0054] Specifically, as shown in the figure, Figure 4 The insulation resistance detection circuit comprises a positive insulation resistance RP, a negative insulation resistance RN, a resistor RSP, a resistor RSN, a resistor RAMC, a switch SP, a switch SN, an isolation operational amplifier OP1, an operational amplifier OP2 and a voltage source U1.

[0055] The positive insulation resistance RP and the negative insulation resistance RN are virtual resistances provided by the battery cluster and can be regarded as the resistance between the positive and negative poles of the battery cluster and the ground. The switch SP, the resistor RSP and the resistor RAMC are connected in series and then connected in parallel between the two ends of the resistor RP. The switch SN, the resistor RSN and the resistor RAMC are connected in series and then connected in parallel between the two ends of the resistor RN. The two ends of the resistor RAMC are connected to the two input ends of the isolation operational amplifier OP1, the two output ends of the isolation operational amplifier OP1 are connected to the two input ends of the operational amplifier OP2, and the output end of the operational amplifier OP2 is connected to the reverse input end thereof, thereby forming a reverse proportional amplification circuit. Finally, the sampling result is output to the BCMU for data processing, so as to obtain the insulation resistance data.

[0056] The contactor control circuit comprises a fuse, a circuit breaker and positive and negative contactors. The high-voltage positive pole of the battery cluster is connected to the positive contactor, the positive contactor is connected to the fuse, the fuse is connected to the circuit breaker, and the circuit breaker is directly connected to the positive pole of the DC bus. The high-voltage negative pole of the battery cluster is directly connected to the DC bus through the negative contactor. The fuse, the circuit breaker and the positive and negative contactors are directly controlled by the main control chip.

[0057] The CAN bus communication circuit is directly connected to the data interface of the main control chip and is equipped with a CAN controller and a physical layer transceiver, thereby realizing the bidirectional data exchange between the battery cluster main control module BCMU and the subordinate battery pack main control module BMU and the superior energy storage system main control module BSMU.

[0058] Further, there is an energy storage system main control module BSMU superior to the multiple battery cluster main control modules BCMU. The main control module obtains the state information of each battery cluster and controls the subordinate multiple battery cluster main control modules BCMU to perform the clustering operation through the CAN bus communication circuit.

[0059] Correspondingly, the application also provides a control method applied to the high-voltage battery cluster clustering control system. Figure 2 and Figure 3 The control method comprises the following steps:

[0060] Step one, the energy storage system master module BSMU initiates a request data upload instruction to the battery cluster master module BCMU1~BCMUn through the CAN bus communication circuit. Further, when the corresponding battery cluster master module BCMUi receives the request data upload instruction, it will immediately return the response information to the energy storage system master module BSMU. If the BSMU does not receive the response information of the corresponding battery cluster master module BCMUi within 20MS, it will resend the request data upload instruction and wait for 40MS. If the BSMU does not receive the response information of the corresponding battery cluster master module BCMUi within 40MS, it will resend the request data upload instruction and wait for 80MS. If the BSMU does not receive the response information of the corresponding battery cluster master module BCMUi within 80MS, it is considered that the battery cluster master module BCMUi sends a response failure, and it will not be clustered.

[0061] Step two, the battery cluster master module BCMUi obtains the battery cluster voltage and the positive and negative insulation resistances of the battery cluster through the battery cluster voltage and current sampling circuit and the insulation resistance detection circuit, respectively, and uploads the corresponding information to the energy storage system master module BSMU through the CAN bus communication circuit.

[0062] Further, the detection method of the insulation resistance detection circuit in the step two is:

[0063] Let the battery cluster voltage obtained by the battery cluster voltage and current sampling circuit be V.

[0064] First, control the switch SP to attract and the switch SN to break, and let the voltage drop on the resistor RP be VP. Then, according to Kirchhoff's voltage law, we have,

[0065]

[0066] Let the voltage drop on the resistor RAMC at this time be V1, then

[0067]

[0068] Similarly, control the switch SN to attract and the switch SP to break, and let the voltage drop on the resistor RN be VN. Then, according to Kirchhoff's voltage law, we have,

[0069] Electric

[0070]

[0071] Let the voltage drop on the resistor RAMC at this time be V2, then

[0072]

[0073] Let the resistance RSP and resistance RSN resistance are RST, combined with formula (1) (3) can be obtained,

[0074]

[0075]

[0076] VN and VP can be derived from formula (2) (4). V1 and V2 in formula (2) (4) can be calculated by the following way: the voltage drop generated by the resistance RAMC is output as a differential analog voltage signal by the isolation operational amplifier OP1, and then the analog voltage signal is output to the BCMU through the differential signal to single-ended signal circuit composed of operational amplifier OP2, and the insulation resistance data is obtained through the data processing of the BCMU.

[0077] Step three, the energy storage system master module BSMU selects the battery cluster that meets the cluster condition according to the battery cluster voltage and positive and negative insulation resistance information uploaded by the battery cluster master module BCMU1-BCMUn. If the cluster voltage of a certain battery cluster is not within the preset range, it is considered that the battery cluster voltage is faulty, and the clustering operation is not performed. If the positive and negative insulation resistance of a certain battery cluster is not within the preset range, it is considered that the insulation resistance of the battery cluster is faulty, and the clustering operation is not performed. If the battery cluster meets the clustering condition, a same battery pack voltage reference V is sent to each BCMU that meets the clustering condition.

[0078] Step four, the battery cluster master module BCMUi controls the subordinate multiple battery pack master modules BMU through the CAN bus to perform equalization control first. After equalization, the battery pack master module BMU is controlled to switch to the voltage stabilization mode, so that each battery pack is stabilized to the battery pack voltage reference V.

[0079] Step five, after the battery cluster master module BCMUi detects that each battery pack master module BMU reaches the voltage reference V, the corresponding battery cluster is merged into the DC bus through the contactor control circuit.

[0080] Further, the control method of the battery cluster master module BCMU on the subordinate multiple battery pack master modules BMU in step four includes the following steps:

[0081] Step 4.1, the battery cluster master module BCMU initiates a data upload instruction to the battery pack master module BMU1-BMUn through the CAN bus communication circuit.

[0082] Step 4.2, the battery cluster master module BCMU calculates the SOC of each battery according to the voltage and current data uploaded by the battery master module BMUi. After the calculation, the equalization command is sent to the battery master module BMUi to control the equalization of the battery not within the preset SOC threshold;

[0083] Step 4.3, the battery master module BMUi controls the DCDC circuit and the switch matrix circuit to equalize the corresponding battery, and returns the new voltage and current data to the battery cluster master module BCMU for iterative update of the SOC;

[0084] Step 4.4, the battery cluster master module BCMU calculates that a certain group of battery has been equalized, and sends a command to control it to switch to the voltage stabilization mode, so that the output voltage is stabilized at the voltage reference V;

[0085] Step 4.5, the battery cluster master module BCMU detects that each group of battery under it has switched to the voltage stabilization mode, and the output voltage is stabilized at the voltage reference V, and executes the parallel cluster operation;

[0086] In the embodiment, each group of battery contains 12 single batteries, and the equalization effect of a certain group of battery is as shown in the figure Figure 5 The initial SOC of the 12 single batteries is 60%, 58%, 56%, 54%, 52%, 50%, 48%, 46%, 44%, 42%, 40%, and 38%, respectively. After equalization, the SOC of each battery tends to be consistent. After equalization, the voltage of each group is set to be stabilized at 26.4V, and it is verified that the voltage of each group of battery is actually stabilized at 26.4V, and the voltage of the whole battery cluster is stabilized at 792V. Thus, the voltage difference of each cluster of battery cluster is within the threshold range when the clusters are connected in parallel, and the overall circulating loss is minimized.

[0087] Obviously, the embodiments described in the present application are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

Claims

1. A method for controlling the parallel operation of high-voltage battery clusters, used to implement a high-voltage battery cluster parallel control system, the system comprising: Several batteries are connected in series to form a battery pack, and each battery pack is managed and controlled by a battery pack master control module (BMU). The battery pack main control module (BMU) includes a temperature sampling circuit, a first voltage and current sampling circuit, a DC-DC circuit, a switch matrix circuit, and a CAN bus communication circuit. The control method comprises the following steps: Step 1: The main control module BSMU of the energy storage system initiates a data upload request command to the main control modules BCMU1~BCMUn of the battery cluster through the CAN bus communication circuit; Step 2: The battery cluster main control module BCMui, according to the requested data upload command, obtains the battery cluster voltage and positive and negative insulation resistance of the battery cluster through the battery cluster voltage and current sampling circuit and the insulation resistance detection circuit, and uploads the corresponding information to the energy storage system main control module BSMU through the CAN bus communication circuit. Step 3: The energy storage system main control module BSMU selects battery clusters that meet the clustering conditions based on the battery cluster voltage and positive and negative insulation resistance information uploaded by the battery cluster main control modules BCMU1~BCMUn, and sends a battery pack voltage reference V to each BCMU that meets the clustering conditions. Step 4: The battery cluster master control module BCMui that meets the clustering conditions controls multiple lower-level battery pack master control modules BMU through the CAN bus to perform equalization control first; after equalization is completed, the battery pack master control module BMU is controlled to switch to voltage regulation mode, so that each battery pack is stabilized to the battery pack voltage reference V. Step 5: After the battery cluster main control module BCMui detects that each of the lower-level battery pack main control modules BMU has reached the voltage reference V, it connects the corresponding battery cluster to the DC bus through the contactor control circuit.

2. The high-voltage battery cluster parallel control method according to claim 1, characterized in that, The specific implementation process of step four is as follows: Step 4.1: The battery cluster main control module BCMU initiates a data upload request command to the battery pack main control modules BMU1~BMUn through the CAN bus communication circuit; Step 4.2: The Battery Cluster Main Control Module (BCMU) calculates the State of Charge (SOC) of each battery cell based on the voltage and current data uploaded by the Battery Pack Main Control Module (BMUi); then it sends an equalization command to the Battery Pack Main Control Module (BMUi) to control it to equalize batteries that are not within the preset SOC threshold. Step 4.3: The battery pack main control module BMUi controls the DC-DC circuit and the switching matrix circuit to balance the corresponding batteries and returns new voltage and current data to the battery cluster main control module BCMU to perform iterative updates of SOC. Step 4.4: Once the Battery Cluster Main Control Module (BCMU) calculates that a certain battery pack has been balanced, it sends a command to control it to switch to voltage regulation mode, so that its output voltage is stabilized at the voltage reference V. Step 4.5: The battery cluster main control module (BCMU) detects that each downstream battery group has switched to voltage regulation mode and the output voltage is stable at the voltage reference V, and then performs the clustering operation.

3. The high-voltage battery cluster parallel control method according to claim 2, characterized in that, The temperature sampling circuit includes multiple temperature sensors, which are respectively arranged in the heat-sensitive area of ​​the battery. The temperature sensors are directly connected to the main control chip of the battery pack main control module (BMU) and convert the collected analog signals into digital signals and transmit them to the battery pack main control module (BMU) for analysis and processing. The first voltage and current sampling circuit consists of a voltage sensor and a current sensor to monitor the voltage and current changes of the battery cell in real time. The output terminals of the voltage sensor and the current sensor are connected to the analog-to-digital converter (ADC), which then sends the data to the main control module for analysis and processing. The DC-DC circuit is connected in series with the first battery pack to form a second battery pack, and multiple second battery packs are connected in series to form a battery cluster; the positive terminal one of the DC-DC circuit is connected to the positive terminal of the second battery pack, the negative terminal one is connected to the positive terminal of the first battery pack, the positive terminal two is connected to the positive terminal of the first battery pack, and the negative terminal two is connected to the negative terminal of the first battery pack.

4. The high-voltage battery cluster parallel control method according to claim 3, characterized in that, The switching matrix circuit is combined with the DC-DC circuit for active balancing within the battery pack before clustering. After equalization is completed, the switching matrix circuit switches to DC-DC circuit and switches to voltage regulation mode, so that the second battery pack outputs a constant voltage. The battery pack consists of two cells, one odd-numbered and one even-numbered. The positive terminal of the odd-numbered cells, which is the negative terminal of the even-numbered cells, is connected to polarity switches S3 and S4 via a switch. The negative terminal of the odd-numbered cells, which is the positive terminal of the even-numbered cells, is connected to polarity switches S1 and S2 via a switch. Polarity switches S1 and S3, and S2 and S4 are connected to the positive and negative terminals of the DC-DC circuit, respectively.

5. The high-voltage battery cluster parallel control method according to claim 4, characterized in that, Each battery cluster is managed and controlled by a Battery Cluster Main Control Module (BCMU), which controls multiple lower-level Battery Pack Main Control Modules (BMUs) to perform equalization and voltage regulation operations. The Battery Cluster Main Control Module (BCMU) includes a contactor control circuit, a second voltage and current sampling circuit, an insulation resistance detection circuit, and a CAN bus communication circuit.

6. The high-voltage battery cluster parallel control method according to claim 5, characterized in that, The second voltage and current sampling circuit acquires voltage and current information through Hall voltage sensors and Hall current sensors to monitor the safety status of the battery cluster; the output terminals of the Hall voltage sensors and Hall current sensors are connected to the ADC, and the ADC then sends the data to the battery cluster main control module BCMU for analysis and processing. Before clustering, sample the battery cluster voltage to determine whether its voltage meets the clustering conditions; The insulation resistance detection circuit detects the positive and negative insulation resistance of the battery cluster, outputs the detection results to the battery cluster main control module BCMU, obtains the positive and negative insulation resistance of the corresponding battery cluster before clustering, and determines whether it meets the clustering conditions. The contactor control circuit consists of a fuse, a circuit breaker, and positive and negative contactors. The positive terminal of the battery cluster is connected to the positive contactor, which is then connected to the fuse, which is in turn connected to the circuit breaker. The circuit breaker is directly connected to the positive terminal of the DC bus. The negative terminal of the battery cluster is directly connected to the DC bus via the negative contactor. The fuse, circuit breaker, and positive and negative contactors are all directly controlled by the main control chip.

7. The high-voltage battery cluster parallel control method according to claim 6, characterized in that, An energy storage system main control module (BSMU) is provided above the multiple battery cluster main control modules (BCMUs). The BSMU obtains the status information of each battery cluster through a CAN bus communication circuit and controls the multiple lower-level battery cluster main control modules (BCMUs) to perform clustering operations.

8. The high-voltage battery cluster parallel control method according to claim 7, characterized in that, The CAN bus communication circuit is equipped with a CAN controller and a physical layer transceiver to realize bidirectional data exchange between the battery pack main control module (BMU) and the battery cluster main control module (BCMU), and between the battery cluster main control module (BCMU) and the energy storage system main control module (BSMU).

9. A method for controlling the parallel operation of high-voltage battery clusters according to claim 8, characterized in that, The battery pack main control module (BMU), battery cluster main control module (BCMU), and energy storage system main control module (BSMU) all use a microcontroller as the main control chip.

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