High-power high-frequency modular battery cluster charging and discharging test equipment and method

Abstract

The invention provides a high-power high-frequency modular battery cluster charging and discharging test device, which is characterized by comprising an alternating current coordination controller connected with a middle computer and used for receiving an instruction transmitted by the middle computer and distributing current to a plurality of isolated ACDC modules; the input ends of the plurality of isolated ACDC modules are connected in parallel and then are connected to the AC co-controller and a three-phase mains supply, and the output ends of the plurality of isolated ACDC modules are connected in parallel and then form a DC bus for converting AC into DC and realizing voltage isolation; and a plurality of BUCK-BOOST modules, the input ends of the plurality of BUCK-BOOST modules are connected in parallel and then are connected to the DC bus, and the output ends of the plurality of BUCK-BOOST modules are connected in parallel and then are connected to a target battery cluster for testing the charging and discharging of the target battery cluster. Modular design is achieved, efficient charging and discharging capacity is achieved, the defects that a traditional scheme is large in size, high in cost, slow in dynamic response and the like are overcome, equipment efficiency and flexibility are improved, and the device is suitable for a high-power scene.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to a high-power high-frequency modular battery cluster charge and discharge test device and method. Background Art

[0002] With the rapid development of lithium-ion battery technology, electrochemical energy storage technology has been widely used in many fields due to its advantages of high energy density, long life and high efficiency. In the research and development, production, testing and other links of lithium-ion batteries, charge and discharge test equipment plays an indispensable role as a key tool. With the continuous advancement of technology and the rapid growth of industry demand, higher requirements have been put forward for the technical indicators of battery charge and discharge test equipment, such as supporting higher voltage levels, larger power ranges, higher test accuracy and faster dynamic response speeds. These requirements have brought great challenges to traditional test equipment solutions.

[0003] At present, the mainstream battery cluster charging and discharging test equipment on the market usually adopts a technical solution that combines power frequency transformers, high-power ACDC bidirectional converters and BUCK-BOOST DCDC bidirectional converters. The power frequency transformer provides the necessary voltage conversion and safety isolation for the circuit; the high-power ACDC bidirectional converter is used to realize the energy exchange between the power grid and the DC bus; and the BUCK-BOOST DCDC bidirectional converter is used to realize the voltage regulation and energy control between the DC bus and the battery cluster under test. However, this solution has significant shortcomings in practical applications, such as the power frequency transformer is large in size, heavy in weight, and high in noise; the ACDC bidirectional converter has a low switching frequency, resulting in high noise, a large number of devices, a large size, and high cost; the BUCK-BOOST DCDC converter has a slow dynamic response speed. In addition, the test equipment of this solution needs to be redesigned when the parameters change, the customization cost is high, the production cycle is long, and the after-sales maintenance is complicated, which makes it difficult to meet the urgent needs of the new energy vehicle and energy storage industries for high-performance charging and discharging test equipment. Summary of the invention

[0004] In view of this, the present invention is committed to providing a high-power high-frequency modular battery cluster charge and discharge test device and method, which is used to solve the problems in the prior art of large equipment size, high weight, insufficient dynamic response performance, high production cost, and high difficulty in customized design and maintenance.

[0005] In a first aspect, the present invention provides a high-power high-frequency modular battery cluster charge and discharge test device, the device comprising: An AC co-controller, connected to the intermediate computer, for receiving instructions transmitted by the intermediate computer and distributing current to a plurality of isolated ACDC modules; A plurality of isolated ACDC modules, wherein the input ends of the plurality of isolated ACDC modules are connected in parallel to the AC cooperative controller and the three-phase mains power supply, and the output ends are connected in parallel to form a DC bus for converting AC power into DC power and realizing voltage isolation; A plurality of BUCK-BOOST modules, wherein input ends of the plurality of BUCK-BOOST modules are connected in parallel to the DC bus, and output ends of the plurality of BUCK-BOOST modules are connected in parallel to a target battery cluster, for testing the charge and discharge of the target battery cluster.

[0006] Optionally, each isolated ACDC module includes: A three-phase DNPC topology unit includes a first capacitor C1, a second capacitor C2, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a fourth switch tube Q4, a first inductor L1, a first diode D1 and a second diode D2; The first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 are connected in series, the collector of the first switch tube Q1 is connected to the positive electrode of the power supply, and the emitter of the fourth switch tube Q4 is connected to the negative electrode of the power supply; One end of the first capacitor is connected to the collector of the first switch tube Q1, and the other end is connected to the B-phase mains input and the C-phase mains input; One end of the first inductor L1 is connected between the emitter of the second switch tube Q2 and the collector of the third switch tube Q3, and the other end is connected to the A-phase mains input; The cathode of the first diode D1 is connected between the emitter of the first switch tube Q1 and the collector of the second switch tube Q2, and the anode of the first diode D1 is grounded; the anode of the second diode D2 is connected between the emitter of the third switch tube Q3 and the collector of the fourth switch tube Q4, and the cathode of the second diode D2 is grounded; One end of the second capacitor C2 is connected to the A-phase mains input, and the other end is grounded.

[0007] Optionally, each isolated ACDC module further includes: The LLC isolated DCDC unit includes a transformer T1, a third capacitor C3, a fourth capacitor C4, a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7, an eighth switch tube Q8, a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11 and a twelfth switch tube Q12; The fifth switch tube Q5 and the sixth switch tube Q6 are connected in series, the drain of the fifth switch tube Q5 is connected to the positive electrode of the power supply, and the source of the sixth switch tube Q6 is connected to the negative electrode of the power supply; the seventh switch tube Q7 and the eighth switch tube Q8 are connected in series, the drain of the seventh switch tube Q7 is connected to the positive electrode of the power supply, and the source of the eighth switch tube Q8 is connected to the negative electrode of the power supply; The ninth switch tube Q9 and the tenth switch tube Q10 are connected in series, the drain of the ninth switch tube Q9 is connected to the positive electrode of the DC bus, and the source of the tenth switch tube Q10 is connected to the negative electrode of the DC bus; the eleventh switch tube Q11 and the twelfth switch tube Q12 are connected in series, the drain of the eleventh switch tube Q11 is connected to the positive electrode of the DC bus, and the source of the twelfth switch tube Q12 is connected to the negative electrode of the DC bus; one end of the fourth capacitor is connected to the positive electrode of the DC bus, and the other end is connected to the negative electrode of the DC bus; The first port of the transformer T1 is connected between the source of the fifth switch tube Q5 and the drain of the sixth switch tube Q6 through the third capacitor C3; the second port of the transformer T1 is connected between the source of the seventh switch tube Q7 and the drain of the eighth switch tube Q8; the third port of the transformer T1 is connected between the source of the eleventh switch tube Q11 and the drain of the twelfth switch tube Q12; the fourth port of the transformer T1 is connected between the source of the ninth switch tube Q9 and the drain of the tenth switch tube Q10.

[0008] Optionally, each BUCK-BOOST module includes a fifth capacitor C5, a sixth capacitor C6, a thirteenth switch tube Q13, a fourteenth switch tube Q14 and a second inductor; One end of the fifth capacitor C5 is connected to the positive electrode of the DC bus, and the other end is connected to the negative electrode of the DC bus; The thirteenth switch tube Q13 and the fourteenth switch tube Q14 are connected in series, the drain of the thirteenth switch tube Q13 is connected to the positive electrode of the DC bus, and the source of the fourteenth switch tube Q14 is connected to the negative electrode of the DC bus; One end of the second inductor L2 is connected between the source of the thirteenth switch tube Q13 and the drain of the fourteenth switch tube Q14, and the other end is connected to the positive electrode of the battery cluster; One end of the sixth capacitor C6 is connected between the second inductor L2 and the positive electrode of the battery cluster, and the other end is connected to the negative electrode of the battery cluster.

[0009] Optionally, the AC cooperative controller is also connected to the DC bus via a DC bus voltage sampling line, for sampling the voltage of the DC bus; The AC cooperative controller is also connected to the three-phase mains via a three-phase mains voltage sampling line, and is used to sample the voltage of the three-phase mains.

[0010] Optionally, the output ends of the multiple BUCK-BOOST modules are connected in parallel to form multiple independent channels, and each channel is connected to a different battery cluster, so as to perform independent charge and discharge tests on each battery cluster.

[0011] Optionally, the device further includes: A plurality of channel controllers are respectively arranged corresponding to the plurality of independent channels, and an input end of each channel controller is connected to the battery cluster under test, so as to collect voltage and current information of the battery cluster under test in real time, and transmit the collected data to the intermediate computer; an output end of each channel controller is connected to an input end of a corresponding BUCK-BOOST module, so as to control the voltage and current of the corresponding BUCK-BOOST module.

[0012] Optionally, the channel controller controls the output voltage and output current of the corresponding BUCK-BOOST module according to the collected voltage and current information of the tested battery cluster, so that the current is evenly distributed among the multiple BUCK-BOOST modules.

[0013] Optionally, the AC cooperative controller calculates the target current value of each isolated ACDC module through a control algorithm based on the sampled DC bus voltage and the three-phase mains voltage, and sends a current distribution instruction to the multiple isolated ACDC modules to achieve current sharing control among the multiple isolated ACDC modules.

[0014] In a second aspect, the present invention further provides a high-power high-frequency modular battery cluster charge and discharge test method, the method comprising: The three-phase mains voltage and the DC bus voltage are sampled by the AC cooperative controller, and the target current value is calculated based on the sampling results; Distribute the target current value to multiple isolated ACDC modules, and control the multiple isolated ACDC modules to operate in current-sharing mode; The DC bus voltage is converted into a voltage suitable for the target battery cluster through multiple BUCK-BOOST modules to charge or discharge the target battery cluster; The voltage and current of the target battery cluster are collected by a channel controller, the output voltage and current of multiple BUCK-BOOST modules are adjusted based on the collected data, and the current distribution between the multiple BUCK-BOOST modules is adjusted to achieve current sharing control.

[0015] According to the solution of the present invention and the above-mentioned embodiments, a highly integrated and modularized architecture of the equipment is achieved by adopting a modular design of an AC co-controller, multiple isolated ACDC modules, a DC bus, and multiple BUCK-BOOST modules. The high-power, high-frequency modular battery cluster charge and discharge test equipment of the present invention can efficiently convert three-phase AC power into DC power and transmit it to multiple BUCK-BOOST modules through a DC bus, supporting charge and discharge tests on target battery clusters. The modular design enables the equipment to be flexibly expanded at different power and current levels, significantly reducing the types and quantity of equipment, and simplifying the R&D, production, and after-sales processes. At the same time, the use of an isolated ACDC module realizes voltage conversion and electrical isolation, has the advantages of low noise, small size, and light weight, improves conversion efficiency, and meets complex testing requirements.

[0016] Furthermore, by using the AC co-controller to achieve accurate current distribution for multiple isolated ACDC modules, the system can maintain current-balanced operation, significantly improving stability and operating efficiency. At the same time, the independent adjustment of multiple BUCK-BOOST modules ensures precise control of the battery cluster during charging and discharging, and optimizes the dynamic response performance of the equipment. This design not only improves the accuracy and reliability of the test, but also enhances the adaptability of the equipment in complex test environments, and improves the overall conversion efficiency and operating performance of the system. In addition, by connecting multiple BUCK-BOOST modules to the target battery cluster, multi-channel parallel operation can be achieved, and energy exchange can be performed between multiple battery clusters, which greatly improves the system's test efficiency and power utilization, and further optimizes the performance of the equipment.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a high-power high-frequency modular battery cluster charge and discharge test device according to an embodiment of the present invention is shown; Figure 2 shows a circuit diagram of an isolated ACDC module according to one embodiment of the present invention; Figure 3 shows a circuit diagram of a BUCK-BOOST module according to an embodiment of the present invention; Figure 4 A schematic flow chart of a high-power high-frequency modular battery cluster charge and discharge test method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention rather than all structures are shown in the accompanying drawings. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] The terms "including" and "having" and any variations thereof in the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0021] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] Existing battery cluster charging and discharging equipment usually adopts a combination of power frequency transformer, high-power AC-DC bidirectional converter and BUCK-BOOST DC-DC bidirectional converter. This solution is widely adopted due to its stability, reliability and technical maturity. The power frequency transformer can provide good voltage isolation and overload protection. Its stability and durability have been verified for a long time in high-power and high-current applications. However, the power frequency transformer is large in size, heavy in weight and low in efficiency. Especially in high-frequency and high-power applications, the size and weight of the transformer restrict the energy efficiency and response speed of the overall equipment. In addition, the adjustment flexibility of the power frequency transformer is poor, and it is difficult to quickly adapt to the dynamic changes in the complex battery charging and discharging process. Because this technical solution has been applied and verified for a long time, and has a high market acceptance and a lot of use experience, the industry has gradually formed a technical bias and generally believes that this is the most reliable and stable solution. Therefore, many developers and designers tend to continue this traditional thinking mode and lack the exploration and trial of new solutions. This inertial thinking limits the breakthrough of new technologies and makes it difficult for innovative technologies to enter the mainstream application field.

[0023] After breaking the prejudice of existing technology, the inventors chose to use LLC isolated DCDC converter for voltage conversion and isolation. However, in the early stage of research and development, the inventors still faced many challenges and technical difficulties.

[0024] During the initial development process, the inventors used a three-phase DNPC (Dual Active Bridge with NeutralPoint Clamped) unit as a current conversion module and worked alone, while connecting the LLC isolated DCDC unit with the BUCK-BOOST module into an integral module for voltage conversion and isolation. Although this design can meet the basic voltage conversion and isolation requirements, there are significant cost increases and power loss problems in practical applications. The reason is that when the two tested battery clusters in the dual channel are in the charging and discharging states respectively, the energy exchange needs to pass through the LLC isolated DCDC unit, thereby introducing additional energy conversion losses. This is because in this design, even if only one channel needs to be converted to voltage, the energy of the other channel still needs to pass through the LLC isolated DCDC unit, resulting in unnecessary losses and reducing overall efficiency.

[0025] In addition, when the three-phase DNPC unit works alone as a current conversion module, it is usually directly connected to the three-phase mains power supply for current conversion. Although this solution can theoretically achieve current conversion, it also brings a series of technical and systemic problems. First, the lack of precise current regulation and distribution mechanism leads to unbalanced current distribution among modules. This current imbalance will cause an increase in power loss, thereby reducing the overall system efficiency. In addition, since the three-phase DNPC unit is working as a voltage source at this time, there is no effective parallel connection capability at the output end, and a stable DC bus cannot be formed, which makes it impossible for multiple modules to work in coordination, seriously affecting the scalability and reliability of the system. In the absence of effective current management, the system may cause some modules to be overloaded or even damaged, increasing the risk of equipment failure. At the same time, this design limits the adaptability of the system in high-voltage and high-power scenarios, which significantly affects the working stability and long-term operation capability of the equipment.

[0026] Therefore, although the inventors broke the traditional technical prejudice in the early research and development process and used the three-phase DNPC module and LLC isolated DCDC module separately, they failed to effectively integrate the current conversion and voltage conversion functions, resulting in excessive system power consumption and high cost. Through continuous optimization and improvement, the high-power high-frequency modular battery cluster charge and discharge test equipment and method of the present invention were finally introduced, breaking the limitations of traditional designs and achieving efficient and stable operation of the battery cluster charge and discharge test equipment.

[0027] Figure 1A schematic diagram of a high-power high-frequency modular battery cluster charge and discharge test device according to an embodiment of the present invention is shown. Figure 1 As shown, the device includes: The AC cooperative controller is connected to the intermediate computer, and is used to receive instructions transmitted by the intermediate computer and distribute current to multiple isolated ACDC modules.

[0028] Multiple isolated ACDC modules, the input ends of the multiple isolated ACDC modules are connected in parallel to the AC cooperative controller and the three-phase AC power supply, and the output ends are connected in parallel to form a DC bus, which is used to convert AC power into DC power and realize voltage isolation.

[0029] The input ends of multiple isolated ACDC modules are connected in parallel to the CANBUS port of the AC co-controller to receive the current distribution instructions sent by the AC co-controller. At the same time, the input ends of multiple isolated ACDC modules are also connected in parallel to the three-phase mains power supply to convert the three-phase AC power supply of the mains into DC power and provide the DC voltage required by the equipment. In addition, since the AC co-controller assigns the target current value to each isolated ACDC module and controls its output current to remain at the set value, the output ends of multiple isolated ACDC modules can be connected in parallel as current sources. The output ends of multiple isolated ACDC modules are connected in parallel to form a DC bus, which gathers the converted DC power and provides it to other modules in the equipment, ensuring that the DC voltage is stable and can supply power to multiple BUCK-BOOST modules. The DC bus plays the role of power distribution and voltage stability, providing reliable power support for each module of the equipment, while simplifying power transmission and management. In addition, the voltage isolation function of multiple isolated ACDC modules can effectively prevent the impact of mains fluctuations and interference on the equipment, protect other components in the system from grid interference, and thus improve the stability and reliability of the equipment.

[0030] A plurality of BUCK-BOOST modules, input ends of the plurality of BUCK-BOOST modules are connected in parallel to a DC bus, and output ends of the plurality of BUCK-BOOST modules are connected in parallel to a target battery cluster, for testing the charge and discharge of the target battery cluster.

[0031] Multiple BUCK-BOOST modules are connected to the DC bus in parallel through the input end, converting the DC voltage into a voltage that matches the target battery cluster, and taking on the task of charging and discharging the battery cluster. Each BUCK-BOOST module can independently adjust the output voltage and current to ensure precise control of the battery cluster during the charging and discharging process, and meet the voltage and current requirements of different battery clusters. The efficient design of multiple BUCK-BOOST modules improves energy conversion efficiency, reduces energy loss, and ensures stability and accuracy during battery cluster testing. This design can provide reliable power supply when multiple battery clusters are tested in parallel, ensuring the safety and efficiency of the equipment under long-term high-load operation.

[0032] According to the above embodiments, by adopting the modular design of AC co-controller, multiple isolated ACDC modules, DC bus and multiple BUCK-BOOST modules, a highly integrated and modular architecture of the equipment is achieved. The high-power high-frequency modular battery cluster charge and discharge test equipment of the present invention can efficiently convert three-phase AC power into DC power and transmit it to multiple BUCK-BOOST modules through the DC bus, supporting the charge and discharge test of the target battery cluster. The modular design enables the equipment to be flexibly expanded at different power and current levels, significantly reducing the types and quantity of equipment, and simplifying the research and development, production and after-sales process. At the same time, the setting of the isolated ACDC module is used to realize voltage conversion and electrical isolation, with the advantages of low noise, small size, light weight, etc., which improves the conversion efficiency and meets complex testing requirements.

[0033] In some embodiments, reference Figure 1 The AC co-controller of the high-power high-frequency modular battery cluster charge and discharge test equipment of the present invention is also connected to the DC bus through a DC bus voltage sampling line, for sampling the voltage of the DC bus. The AC co-controller is also connected to the three-phase mains through a three-phase mains voltage sampling line, for sampling the voltage of the three-phase mains.

[0034] The AC co-controller monitors the voltage of the DC bus in real time through the DC bus voltage sampling line, and collects the mains voltage information through the three-phase mains voltage sampling line. These data are used to dynamically adjust system parameters to ensure that the DC bus voltage remains within a safe and stable range, and to avoid damage to the equipment and battery cluster caused by overvoltage or undervoltage. At the same time, the mains voltage fluctuations are sampled in real time to optimize the adaptability of the equipment and ensure the stability of voltage conversion and current distribution, thereby improving the operating efficiency and test accuracy of the overall system. This process effectively improves the stability of the system, the equipment protection capability and performance optimization, and ensures the accuracy and reliability of the battery cluster charge and discharge test.

[0035] In some embodiments, the AC cooperative controller calculates the target current value of each isolated ACDC module through a control algorithm based on the sampled DC bus voltage and the three-phase AC power voltage, and sends a current distribution instruction to the multiple isolated ACDC modules to achieve current sharing control among the multiple isolated ACDC modules.

[0036] The AC co-controller samples the DC bus voltage and the three-phase mains voltage, calculates the target current value of each isolated ACDC module using a control algorithm, and sends current distribution instructions to multiple isolated ACDC modules. Through this process, the system can achieve current sharing control between each isolated ACDC module, so that the workload of each module can be balanced. Current sharing control optimizes the use of power resources, improves the overall efficiency of the system, and reduces energy loss by accurately distributing the load of each module. It effectively avoids voltage fluctuations and current shocks caused by uneven current, thereby enhancing the stability of the equipment, and is particularly suitable for high-power and high-frequency battery testing equipment. In addition, current sharing control ensures that each module operates within a reasonable load range, reduces the risk of overload and overheating, extends the service life of the equipment, and reduces maintenance costs. In the battery cluster charge and discharge test, current sharing control also ensures accurate current distribution, eliminates test errors caused by uneven current, and ensures test accuracy. Ultimately, current sharing control greatly reduces the risk of equipment failure and provides system reliability and safety.

[0037] In some embodiments, the output ends of multiple BUCK-BOOST modules of the high-power high-frequency modular battery cluster charge and discharge test equipment of the present invention are connected in parallel to form multiple independent channels, each channel is connected to a different battery cluster, and is used to perform independent charge and discharge tests on each battery cluster.

[0038] The outputs of multiple BUCK-BOOST modules can be connected in parallel to a battery cluster to increase the power level, and can also be connected to multiple different battery clusters to form multiple battery test channels. Multiple BUCK-BOOST modules are connected in parallel via a DC bus to form a common bus structure, which enables energy exchange between different test channels. Specifically, energy can be transferred between test channels via the DC bus, greatly improving the overall efficiency of the system, avoiding the impact of excessive load on a single channel, and enabling the device to flexibly allocate energy between different battery clusters.

[0039] refer to Figure 1The output ends of the first BUCK-BOOST module and the second BUCK-BOOST module are connected in parallel to form a first test channel, which can test a target battery cluster. At the same time, the output ends of the third BUCK-BOOST module and the fourth BUCK-BOOST module are connected in parallel to form a second test channel, which can test another target battery cluster.

[0040] In the actual working process, when the target battery clusters in the first test channel and the second test channel are both in the charging state, the output ends of the first BUCK-BOOST module and the second BUCK-BOOST module of the first channel are connected in parallel to provide the required charging voltage and current to the first target battery cluster. At the same time, the output ends of the third BUCK-BOOST module and the fourth BUCK-BOOST module of the second channel are connected in parallel to provide charging current to another target battery cluster. During the discharge process of the battery cluster, the working principle is similar to that of the charging state. The first BUCK-BOOST module and the second BUCK-BOOST module of the first channel provide discharge current to adapt to the load requirements of the first battery cluster, and adjust the output voltage and current through real-time current and voltage sampling to ensure accurate current control during battery discharge. The working process of the third BUCK-BOOST module and the fourth BUCK-BOOST module of the second channel is similar, and will not be repeated here. When one target battery cluster is in the charging state and the other target battery cluster is in the discharging state, energy exchange can be achieved between the two target battery clusters through the DC bus. The target battery cluster in the discharging state can feedback energy to the DC bus, and this part of energy can be used for the target battery cluster in the charging state to further improve the system efficiency.

[0041] Therefore, the first test channel, the second test channel and the AC side form a bridge for energy exchange through the DC bus. When the demand of the target battery cluster changes, the device can automatically distribute energy to ensure that the charging and discharging process of each battery cluster can be maintained in the best working state. Through this energy exchange mechanism, the device not only improves the overall energy efficiency, but also ensures system stability when multiple battery clusters are tested simultaneously to avoid overload risks.

[0042] In some embodiments, the high-power high-frequency modular battery cluster charge and discharge test equipment of the present invention also includes multiple channel controllers, which are respectively configured to correspond to the multiple independent channels. The input end of each channel controller is connected to the battery cluster under test, so as to collect the voltage and current information of the battery cluster under test in real time, and transmit the collected data to the intermediate computer; the output end of each channel controller is connected to the input end of the corresponding BUCK-BOOST module, so as to control the voltage and current of the corresponding BUCK-BOOST module.

[0043] Multiple channel controllers are connected to the corresponding channels under test through channel voltage and current sampling lines, and the voltage and current data of the battery cluster under test are collected in real time, and the collected data is transmitted to the central computer through a communication interface (such as CAN bus or other transmission methods). After receiving the data, the central computer performs necessary data analysis and processing, and calculates the required voltage and current parameters according to the test requirements. Based on the processing results, the central computer sends corresponding control instructions to each channel controller. The channel controller controls the corresponding BUCK-BOOST module through these instructions to adjust the output voltage and current to accurately meet the charging and discharging requirements of the battery cluster.

[0044] The channel controller collects the voltage and current data of the battery cluster in real time, combined with the precise calculation of the intermediate computer, to ensure accurate control and efficient regulation during the charging and discharging process, thereby improving the test accuracy and stability of the equipment. Each channel controller independently controls the corresponding BUCK-BOOST module, avoiding interference between channels and enhancing the adaptability and flexibility of the system, especially when testing multiple battery clusters in parallel. This independent control method enables the equipment to quickly respond to the dynamic changes of the battery cluster, provide personalized charging and discharging solutions, optimize test efficiency, and ensure the long-term stable operation of the equipment.

[0045] In some embodiments, the channel controller controls the output voltage and output current of the corresponding BUCK-BOOST module according to the collected voltage and current information of the tested battery cluster, so that the current between multiple BUCK-BOOST modules is evenly distributed. Each channel controller monitors the voltage and current status of the tested battery cluster in real time, and transmits the collected data to the central computer for processing. The central computer calculates the output current and voltage required for each BUCK-BOOST module based on the voltage and current data of the battery cluster and the preset charge and discharge strategy. The central computer generates control instructions based on the calculation results and sends these instructions to each channel controller. After receiving the control instruction, the channel controller adjusts the output voltage and current of the corresponding BUCK-BOOST module to ensure that the current output by each module is evenly distributed, thereby avoiding the situation where a certain module is overloaded or some modules are insufficient in current. Through precise current control, all BUCK-BOOST modules maintain load balance when working in parallel, ensuring that the charging and discharging process of the battery cluster is stable and accurate. When multiple battery clusters work at the same time, the uniform distribution of current can also effectively avoid mutual interference and improve the overall efficiency and stability of the system.

[0046] Through the precise adjustment of each BUCK-BOOST module by the channel controller, the current of multiple modules is evenly distributed during the charging and discharging process, and the load is shared to avoid energy waste, test errors and equipment damage caused by unbalanced loads. This design not only improves the efficiency and stability of the system, but also improves the test accuracy, extends the service life of the equipment, and effectively reduces the risk of failure, providing reliable protection for the charging and discharging test of high-power battery clusters.

[0047] Figure 2 FIG. 2 shows a circuit diagram of an isolated ACDC module according to an embodiment of the present invention. Figure 2 As shown, each isolated ACDC module includes: The three-phase DNPC topology unit includes a first capacitor C1, a second capacitor C2, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a fourth switch tube Q4, a first inductor L1, a first diode D1 and a second diode D2.

[0048] The first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 are connected in series, the collector of the first switch tube Q1 is connected to the positive pole of the power supply, and the emitter of the fourth switch tube Q4 is connected to the negative pole of the power emitter.

[0049] The first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 are IGBT devices, which are connected in series to form a bridge arm structure. By controlling the on and off of these switch tubes, the three-phase AC voltage is rectified into DC power, thereby realizing AC voltage rectification and energy transfer.

[0050] One end of the first capacitor C1 is connected to the collector of the first switch tube Q1, and the other end is connected to the B-phase mains input and the C-phase mains input. One end of the first inductor L1 is connected between the emitter of the second switch tube Q2 and the collector of the third switch tube Q3, and the other end is connected to the A-phase mains input. The cathode of the first diode D1 is connected between the emitter of the first switch tube Q1 and the collector of the second switch tube Q2, and the anode of the first diode D1 is grounded; the anode of the second diode D2 is connected between the emitter of the third switch tube Q3 and the collector of the fourth switch tube Q4, and the cathode of the second diode D2 is grounded. One end of the second capacitor C2 is connected to the A-phase mains input, and the other end is grounded.

[0051] The first inductor L1 is connected to the A-phase mains input, and plays the role of energy storage and filtering. When the switch tube is switched, the inductor can prevent the current from changing suddenly and make the current smoother. The first capacitor C1 is connected between the collector of the first switch tube Q1 and the B-phase and C-phase mains inputs, and plays the role of filtering and energy storage, which helps to stabilize the voltage. The second capacitor C2 is connected between the A-phase mains input and the ground, and further filters and reduces voltage fluctuations. The first diode D1 and the second diode D2 clamp the midpoint voltage respectively to ensure the stability and symmetry of the output voltage, and at the same time play the role of suppressing voltage spikes. The cathode of the first diode D1 is connected between the emitter of the first switch tube Q1 and the collector of the second switch tube Q2, and the anode is grounded, which is used to clamp the midpoint voltage between Q1 and Q2. The anode of the second diode D2 is connected between the emitter of the third switch tube Q3 and the collector of the fourth switch tube Q4, and the cathode is grounded to ensure the stability of the midpoint voltage between Q3 and Q4. When the switch tube is turned off, the current in the inductor cannot change suddenly. The diode provides a freewheeling path for the inductor current to prevent the generation of voltage spikes.

[0052] The three-phase DNPC topology is adopted, and the midpoint clamping technology is used to reduce the voltage stress of the switching devices, reduce energy loss, and improve rectification efficiency. At the same time, due to the high-frequency operation of the switch tubes Q1-Q4, compared with the traditional power frequency solution, it is more efficient and suitable for high-power scenarios. Compared with the traditional power frequency transformer solution, the isolated ACDC module adopts high-frequency switching technology, which is smaller in size, lighter in weight, and lower in noise, meeting the needs of the new energy vehicle and energy storage industries for lightweight equipment and silent operation.

[0053] In some embodiments, each isolated ACDC module further includes: The LLC isolated DCDC unit includes a transformer T1, a third capacitor C3, a fourth capacitor C4, a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7, an eighth switch tube Q8, a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11 and a twelfth switch tube Q12. The fifth switch tube Q5 and the sixth switch tube Q6 are connected in series, the drain of the fifth switch tube Q5 is connected to the positive electrode of the power supply, and the source of the sixth switch tube Q6 is connected to the negative electrode of the power supply; the seventh switch tube Q7 and the eighth switch tube Q8 are connected in series, the drain of the seventh switch tube Q7 is connected to the positive electrode of the power supply, and the source of the eighth switch tube Q8 is connected to the negative electrode of the power supply. The ninth switch tube Q9 and the tenth switch tube Q10 are connected in series, the drain of the ninth switch tube Q9 is connected to the positive electrode of the DC bus, and the source of the tenth switch tube Q10 is connected to the negative electrode of the DC bus; the eleventh switch tube Q11 and the twelfth switch tube Q12 are connected in series, the drain of the eleventh switch tube Q11 is connected to the positive electrode of the DC bus, and the source of the twelfth switch tube Q12 is connected to the negative electrode of the DC bus; one end of the fourth capacitor is connected to the positive electrode of the DC bus, and the other end is connected to the negative electrode of the DC bus. The first port of the transformer T1 is connected between the source of the fifth switch tube Q5 and the drain of the sixth switch tube Q6 through the third capacitor C3; the second port of the transformer T1 is connected between the source of the seventh switch tube Q7 and the drain of the eighth switch tube Q8; the third port of the transformer T1 is connected between the source of the eleventh switch tube Q11 and the drain of the twelfth switch tube Q12; the fourth port of the transformer T1 is connected between the source of the ninth switch tube Q9 and the drain of the tenth switch tube Q10.

[0054] The fifth switch tube Q5 and the sixth switch tube Q6 are connected in series, and the seventh switch tube Q7 and the eighth switch tube Q8 are connected in series, which constitute the primary side switch network of the LLC resonant converter. By controlling the on and off of these switch tubes, a high-frequency square wave voltage can be generated on the primary side of the transformer T1. For example, when Q5 and Q8 are turned on, the current returns from the positive pole of the power supply through Q5, the primary winding of the transformer T1, and Q8 to the negative pole of the power supply, forming a positive current path. The ninth switch tube Q9 and the tenth switch tube Q10 are connected in series, and the eleventh switch tube Q11 and the twelfth switch tube Q12 are connected in series, which constitute the secondary side switch network. The control of the secondary side switch tube cooperates with the control of the primary side switch tube to realize the transfer of energy from the primary side to the secondary side. For example, when Q5 and Q8 on the primary side are turned on, the corresponding switch tubes on the secondary side (such as Q9 and Q12) will also be turned on to realize the transfer of energy. The third capacitor C3 is connected between the first port of the transformer T1 and the primary side switch tube (Q5 and Q6), and it forms an LLC resonant circuit together with the leakage inductance and excitation inductance of the transformer. This resonant circuit can achieve zero voltage switching (ZVS) of the switch tube and reduce switching losses. The fourth capacitor C4 is connected between the positive and negative poles of the DC bus, and plays a role in filtering and energy storage, which helps to stabilize the DC bus voltage. Transformer T1 plays the role of electrical isolation and voltage conversion. It transfers the energy of the primary side to the secondary side through the principle of electromagnetic induction, and can increase or decrease the voltage according to the turns ratio.

[0055] The LLC isolated DCDC unit achieves electrical isolation between the input and output sides through transformer T1 to ensure the electrical safety of the system. The flexible adjustment capability of the switch duty cycle and operating frequency enables it to adapt to diverse load requirements and achieve precise output voltage regulation. At the same time, the built-in resonant circuit effectively reduces electromagnetic interference and improves electromagnetic compatibility performance; reasonable circuit design and component selection significantly reduce device stress, extend system life, and thus improve overall reliability. The unit has efficient, stable and reliable DC-DC power conversion capabilities and is suitable for a variety of application scenarios.

[0056] Figure 3 FIG. 4 shows a circuit diagram of a BUCK-BOOST module according to an embodiment of the present invention. Figure 3 As shown, each BUCK-BOOST module includes: The fifth capacitor C5, the sixth capacitor C6, the thirteenth switch tube Q13, the fourteenth switch tube Q14 and the second inductor. One end of the fifth capacitor C5 is connected to the positive electrode of the DC bus, and the other end is connected to the negative electrode of the DC bus. The thirteenth switch tube Q13 and the fourteenth switch tube Q14 are connected in series, the drain of the thirteenth switch tube Q13 is connected to the positive electrode of the DC bus, and the source of the fourteenth switch tube Q14 is connected to the negative electrode of the DC bus. One end of the second inductor L2 is connected between the source of the thirteenth switch tube Q13 and the drain of the fourteenth switch tube Q14, and the other end is connected to the positive electrode of the battery cluster. One end of the sixth capacitor C6 is connected between the second inductor L2 and the positive electrode of the battery cluster, and the other end is connected to the negative electrode of the battery cluster.

[0057] The thirteenth switch tube Q13 and the fourteenth switch tube Q14 are connected in series to form a basic Buck-Boost topology. When the thirteenth switch tube Q13 is turned on and the fourteenth switch tube Q14 is turned off, the current passes from the positive pole of the DC bus through the thirteenth switch tube Q13 and the inductor L2 to charge the battery cluster. At this time, the circuit works in the buck mode. When the thirteenth switch tube Q13 is turned off and the fourteenth switch tube Q14 is turned on, the energy in the inductor L2 is released through the fourteenth switch tube Q14 and the battery cluster. At this time, the circuit works in the boost mode. The fifth capacitor C5 is connected between the positive and negative poles of the DC bus, and plays the role of filtering and energy storage, which helps to stabilize the DC bus voltage. The sixth capacitor C6 is connected between the inductor L2 and the battery cluster for filtering and reducing the voltage fluctuation at the battery cluster end.

[0058] The Buck-Boost module achieves bidirectional voltage conversion by controlling the switch tubes Q13 and Q14, and can flexibly adjust the voltage rise and fall between the DC bus and the battery cluster, improving the system adaptability and flexibility. Its topology is highly efficient and energy-saving, reducing energy loss. The filtering function of capacitors C5 and C6 can suppress voltage fluctuations, improve power quality and protect components. Accurate voltage control avoids overcharging and over-discharging of batteries, prolongs battery life, and reasonable design reduces component stress and improves system reliability. It is suitable for DC systems and battery management.

[0059] In summary, according to the above embodiments, the technical solution of the present invention realizes accurate current distribution for multiple isolated ACDC modules through an AC co-controller, and the system can maintain current-balanced operation, which significantly improves stability and operating efficiency. At the same time, the independent adjustment of multiple BUCK-BOOST modules ensures accurate control of the battery cluster during charging and discharging, and optimizes the dynamic response performance of the equipment. This design not only improves the accuracy and reliability of the test, but also enhances the adaptability of the equipment in complex test environments, and improves the overall conversion efficiency and operating performance of the system. In addition, by connecting multiple BUCK-BOOST modules to the target battery cluster, multi-channel parallel operation can be achieved, and energy exchange can be performed between multiple battery clusters, which greatly improves the test efficiency and power utilization of the system, and further optimizes the performance of the equipment.

[0060] Figure 4 FIG. 1 is a flow chart showing a method for charging and discharging a high-power high-frequency modular battery cluster according to an embodiment of the present invention. Figure 4 As shown, the high-power high-frequency modular battery cluster charge and discharge test method includes the following steps: Step S100: sampling the three-phase mains voltage and the DC bus voltage through the AC cooperative controller, and calculating the target current value based on the sampling results.

[0061] Step S200, distributing the target current value to a plurality of isolated ACDC modules, and controlling the plurality of isolated ACDC modules to operate with current sharing.

[0062] Step S300: converting the DC bus voltage into a voltage adapted to the target battery cluster through a plurality of BUCK-BOOST modules, and charging or discharging the target battery cluster.

[0063] Step S400 , collecting the voltage and current of the target battery cluster through the channel controller, adjusting the output voltage and current of multiple BUCK-BOOST modules based on the collected data, and adjusting the current distribution between the multiple BUCK-BOOST modules to achieve current sharing control.

[0064] In the above-mentioned high-power high-frequency modular battery cluster charge and discharge test method, the specific implementation methods of each module and unit refer to the relevant contents of the embodiment of the above-mentioned high-power high-frequency modular battery cluster charge and discharge test equipment, which will not be repeated here.

[0065] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A high-power high-frequency modular battery cluster charge and discharge test equipment, characterized in that: The device comprises: An AC co-controller, connected to the intermediate computer, for receiving instructions transmitted by the intermediate computer and distributing current to a plurality of isolated ACDC modules; A plurality of isolated ACDC modules, wherein the input ends of the plurality of isolated ACDC modules are connected in parallel to the AC cooperative controller and the three-phase mains power supply, and the output ends are connected in parallel to form a DC bus for converting AC power into DC power and realizing voltage isolation; A plurality of BUCK-BOOST modules, wherein input ends of the plurality of BUCK-BOOST modules are connected in parallel to the DC bus, and output ends of the plurality of BUCK-BOOST modules are connected in parallel to a target battery cluster, for testing the charge and discharge of the target battery cluster.

2. The high-power high-frequency modular battery cluster charge and discharge test equipment according to claim 1 is characterized in that: Each isolated ACDC module includes: A three-phase DNPC topology unit includes a first capacitor C1, a second capacitor C2, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a fourth switch tube Q4, a first inductor L1, a first diode D1 and a second diode D2; The first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 are connected in series, the collector of the first switch tube Q1 is connected to the positive electrode of the power supply, and the emitter of the fourth switch tube Q4 is connected to the negative electrode of the power supply; One end of the first capacitor is connected to the collector of the first switch tube Q1, and the other end is connected to the B-phase mains input and the C-phase mains input; One end of the first inductor L1 is connected between the emitter of the second switch tube Q2 and the collector of the third switch tube Q3, and the other end is connected to the A-phase mains input; The cathode of the first diode D1 is connected between the emitter of the first switch tube Q1 and the collector of the second switch tube Q2, and the anode of the first diode D1 is grounded; the anode of the second diode D2 is connected between the emitter of the third switch tube Q3 and the collector of the fourth switch tube Q4, and the cathode of the second diode D2 is grounded; One end of the second capacitor C2 is connected to the A-phase mains input, and the other end is grounded.

3. The high-power high-frequency modular battery cluster charge and discharge test equipment according to claim 1, characterized in that: Each isolated ACDC module also includes: The LLC isolated DCDC unit includes a transformer T1, a third capacitor C3, a fourth capacitor C4, a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7, an eighth switch tube Q8, a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11 and a twelfth switch tube Q12; The fifth switch tube Q5 and the sixth switch tube Q6 are connected in series, the drain of the fifth switch tube Q5 is connected to the positive electrode of the power supply, and the source of the sixth switch tube Q6 is connected to the negative electrode of the power supply; the seventh switch tube Q7 and the eighth switch tube Q8 are connected in series, the drain of the seventh switch tube Q7 is connected to the positive electrode of the power supply, and the source of the eighth switch tube Q8 is connected to the negative electrode of the power supply; The ninth switch tube Q9 and the tenth switch tube Q10 are connected in series, the drain of the ninth switch tube Q9 is connected to the positive electrode of the DC bus, and the source of the tenth switch tube Q10 is connected to the negative electrode of the DC bus; the eleventh switch tube Q11 and the twelfth switch tube Q12 are connected in series, the drain of the eleventh switch tube Q11 is connected to the positive electrode of the DC bus, and the source of the twelfth switch tube Q12 is connected to the negative electrode of the DC bus; one end of the fourth capacitor is connected to the positive electrode of the DC bus, and the other end is connected to the negative electrode of the DC bus; The first port of the transformer T1 is connected between the source of the fifth switch tube Q5 and the drain of the sixth switch tube Q6 through the third capacitor C3; the second port of the transformer T1 is connected between the source of the seventh switch tube Q7 and the drain of the eighth switch tube Q8; the third port of the transformer T1 is connected between the source of the eleventh switch tube Q11 and the drain of the twelfth switch tube Q12; the fourth port of the transformer T1 is connected between the source of the ninth switch tube Q9 and the drain of the tenth switch tube Q10.

4. The high-power high-frequency modular battery cluster charge and discharge test equipment according to claim 1, characterized in that: Each BUCK-BOOST module includes a fifth capacitor C5, a sixth capacitor C6, a thirteenth switch tube Q13, a fourteenth switch tube Q14 and a second inductor; One end of the fifth capacitor C5 is connected to the positive electrode of the DC bus, and the other end is connected to the negative electrode of the DC bus; The thirteenth switch tube Q13 and the fourteenth switch tube Q14 are connected in series, the drain of the thirteenth switch tube Q13 is connected to the positive electrode of the DC bus, and the source of the fourteenth switch tube Q14 is connected to the negative electrode of the DC bus; One end of the second inductor L2 is connected between the source of the thirteenth switch tube Q13 and the drain of the fourteenth switch tube Q14, and the other end is connected to the positive electrode of the battery cluster; One end of the sixth capacitor C6 is connected between the second inductor L2 and the positive electrode of the battery cluster, and the other end is connected to the negative electrode of the battery cluster.

5. The high-power high-frequency modular battery cluster charge and discharge test equipment according to claim 1, characterized in that: The AC cooperative controller is also connected to the DC bus through a DC bus voltage sampling line, and is used to sample the voltage of the DC bus; The AC cooperative controller is also connected to the three-phase mains via a three-phase mains voltage sampling line, and is used to sample the voltage of the three-phase mains.

6. The high-power high-frequency modular battery cluster charge and discharge test equipment according to claim 5, characterized in that: The AC cooperative controller calculates the target current value of each isolated ACDC module based on the sampled DC bus voltage and the three-phase mains voltage through a control algorithm, and sends a current distribution instruction to the multiple isolated ACDC modules to achieve current sharing control among the multiple isolated ACDC modules.

7. The high-power high-frequency modular battery cluster charge and discharge test equipment according to claim 6, characterized in that: The output ends of the multiple BUCK-BOOST modules are connected in parallel to form multiple independent channels, and each channel is connected to a different battery cluster, so as to perform independent charge and discharge tests on each battery cluster.

8. The high-power high-frequency modular battery cluster charge and discharge test equipment according to claim 7, characterized in that: The device also includes: A plurality of channel controllers are respectively arranged corresponding to the plurality of independent channels, and an input end of each channel controller is connected to the battery cluster under test, so as to collect voltage and current information of the battery cluster under test in real time, and transmit the collected data to the intermediate computer; an output end of each channel controller is connected to an input end of a corresponding BUCK-BOOST module, so as to control the voltage and current of the corresponding BUCK-BOOST module.

9. The high-power high-frequency modular battery cluster charge and discharge test equipment according to claim 8, characterized in that: The channel controller controls the output voltage and output current of the corresponding BUCK-BOOST module according to the collected voltage and current information of the tested battery cluster, so that the current is evenly distributed among the multiple BUCK-BOOST modules.

10. A high-power high-frequency modular battery cluster charge and discharge test method for the device according to any one of claims 6 to 9, characterized in that: The method comprises: The three-phase mains voltage and the DC bus voltage are sampled by the AC cooperative controller, and the target current value is calculated based on the sampling results; Distribute the target current value to multiple isolated ACDC modules, and control the multiple isolated ACDC modules to operate in current-sharing mode; The DC bus voltage is converted into a voltage suitable for the target battery cluster through multiple BUCK-BOOST modules to charge or discharge the target battery cluster; The voltage and current of the target battery cluster are collected by a channel controller, the output voltage and current of multiple BUCK-BOOST modules are adjusted based on the collected data, and the current distribution between the multiple BUCK-BOOST modules is adjusted to achieve current sharing control.

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