Multifunctional wide-voltage-range battery charging and discharging device

Abstract

The invention relates to a multifunctional wide-voltage-range battery charging and discharging device which comprises a first ACDC module and a second ACDC module. The cathode of the first capacitor is connected to the anode of the second capacitor through the first switch; a first output end of the first DCDC module outputs outwards through a second switch, and a second output end of the first DCDC module outputs outwards through a third switch; the anode of the third capacitor is connected between the first output end and the second switch, and the cathode is connected between the second output end and the third switch; a second positive input end of the second DCDC module is connected to the first positive input end through a fourth switch, a second negative input end of the second DCDC module is connected to the first negative input end through a fifth switch, and a third output end of the second DCDC module is connected to one end of a fourth capacitor through a sixth switch; the fourth output end is connected to the other end of the fourth capacitor, is externally output through a seventh switch, and is connected to the first output end through a tenth switch; and a fifth output end of the second DCDC module outputs outwards through an eighth switch and is connected to a fourth capacitor through a ninth switch.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to a multifunctional battery charging and discharging device with a wide voltage range. Background Art

[0002] With the rapid development of new energy fields such as electric vehicles and electrochemical energy storage, batteries, as one of the most important core components, undertake the key tasks of system energy storage and release. In practical applications, batteries not only need to undergo performance tests, but also safety tests, durability tests and other tests to ensure their reliability under various working conditions. Due to the diverse application scenarios of batteries, the system voltage range of batteries and battery components is very wide, which puts higher requirements on battery testing devices. To this end, battery research and development, production enterprise laboratories, research institutions, testing centers, etc. need to be equipped with a variety of battery testing devices with different voltage ranges to meet different testing needs. However, these devices usually involve high purchase and maintenance costs. Summary of the invention

[0003] In order to reduce the cost of battery testing equipment, some manufacturers adopt simplified solutions. For example, when testing the battery of the energy storage system, the energy storage inverter is directly used for testing, the DCDC part in the ACDC+DCDC two-stage topology is removed, and only ACDC is used for current control. This solution effectively reduces the cost of the device and reduces the volume, but because the ACDC part only controls the current on the AC side, the current control accuracy on the DC side is low, and control modes such as constant voltage current collection and working condition simulation cannot be achieved. Therefore, the applicable voltage range of this solution is limited, which cannot meet the testing requirements of low-voltage batteries and affects the accuracy and stability of the test. To solve this problem, some companies adopt the solution of connecting the ACDC of the first-level topology with the ACDC+DCDC of the two-level topology in series, which not only improves the performance parameters, but also expands the control mode, and achieves a balance between cost and function. However, this solution still has shortcomings. For example, the performance of the ACDC of the first-level topology may affect the overall performance, and when the battery voltage is lower than the ACDC DC voltage, the device cannot work normally, resulting in reduced power output and unable to meet the requirements of efficient use.

[0004] In order to solve the above technical problems, the present invention proposes a multifunctional wide voltage range battery charging and discharging device, the device comprising: A first ACDC module, wherein a first positive output terminal is connected to the positive electrode of a first capacitor C1, and a first negative output terminal is connected to the negative electrode of the first capacitor C1; A second ACDC module, wherein the second positive output terminal is connected to the positive electrode of the second capacitor C2, and the second negative output terminal is connected to the negative electrode of the second capacitor C2; the negative electrode of the first capacitor C1 is connected to the positive electrode of the second capacitor C2 through the first switch K1; A first DCDC module, wherein the first positive input terminal is connected to the first positive output terminal of the first ACDC module, and the first negative input terminal is connected to the first negative output terminal of the first ACDC module; the first output terminal thereof is output to the outside through the second switch K2, and the second output terminal thereof is output to the outside through the third switch K3; the positive electrode of the third capacitor C3 is connected between the first output terminal and the second switch K2, and the negative electrode thereof is connected between the second output terminal and the third switch K3; A second DCDC module, wherein the second positive input terminal is connected to the second positive output terminal of the second ACDC module, and the second negative input terminal is connected to the second negative output terminal of the second ACDC module; the second positive input terminal is also connected to the first positive input terminal through a fourth switch K4, and the second negative input terminal is also connected to the first negative input terminal through a fifth switch K5; The third output terminal of the second DCDC module is connected to one end of the fourth capacitor C4 through the sixth switch K6, and the fourth output terminal is connected to the other end of the fourth capacitor C4; the fourth output terminal is also output to the outside through the seventh switch K7; the fifth output terminal of the second DCDC module is output to the outside through the eighth switch K8, and is also connected to the fourth capacitor C4 through the ninth switch K9; the fourth output terminal is also connected to the first output terminal through the tenth switch K10.

[0005] Optionally, the fourth switch K4 and the fifth switch K5 are closed or opened at the same time; the first switch K1 and the fourth switch K4 and the fifth switch K5 cannot be closed at the same time; when the fourth switch K4 and the fifth switch K5 are opened, the tenth switch K10 is also opened; the sixth switch K6 and the ninth switch K9 cannot be closed or opened at the same time.

[0006] Optionally, when the test voltage of the multifunctional wide voltage range battery charging and discharging device exceeds a first preset threshold value, the first switch K1, the second switch K2, the sixth switch K6 and the seventh switch K7 are closed, the positive electrode of the battery under test is connected to the first output terminal, and the negative electrode of the battery under test is connected to the fourth output terminal.

[0007] Optionally, when the test voltage of the multifunctional wide voltage range battery charging and discharging device is lower than the first preset threshold and higher than the second preset threshold, the second switch K2, the third switch K3, the seventh switch K7, the eighth switch K8 and the ninth switch K9 are closed; the positive electrode of the first tested battery is connected to the first output terminal, and the negative electrode is connected to the second output terminal; and / or, The positive electrode of the second tested battery is connected to the fourth output terminal, and the negative electrode is connected to the fifth output terminal.

[0008] Optionally, when the first output end is connected in parallel with the fourth output end, and the second output end is connected in parallel with the fifth output end to form a measured channel, the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5, the seventh switch K7, the eighth switch K8, the ninth switch K9 and the tenth switch K10 are closed.

[0009] Optionally, when the test voltage of the multifunctional wide voltage range battery charging and discharging device has a negative value, the second switch K2, the fourth switch K4, the fifth switch K5, the seventh switch K7 and the ninth switch K9 are closed, one end of the battery under test is connected to the first output end, and the other end is connected to the fourth output end.

[0010] Optionally, the first DCDC module and the second DCDC module include a first power tube T1, a second power tube T2, a first diode D1, a second diode D2, a first inductor L1 and a fifth capacitor C5; the first power tube T1 is connected in parallel with the first diode D1, the second power tube T2 is connected in parallel with the second diode D2, and the first power tube T1 is connected in series with the second power tube; one end of the first inductor L1 is connected between the first power tube T1 and the second power tube T2, and the other end is connected to the first output end or the fourth output end; the collector of the first power tube T1 is connected to the sixth output end of the first DCDC module or the third output end of the second DCDC module, and the emitter of the second power tube T2 is connected to the second output end or the fifth output end; the positive electrode of the fifth capacitor C5 is connected to the collector of the first power tube T1, and the negative electrode is connected to the emitter of the second power tube T2.

[0011] Optionally, the first DCDC module and the second DCDC module include a third power tube T3, a fourth power tube T4, a fifth power tube T5, a sixth power tube T6, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a second inductor L2, a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8; the third power tube T3 is connected in parallel with the third diode D3, the fourth power tube T4 is connected in parallel with the fourth diode D4, the fifth power tube T5 is connected in parallel with the fifth diode D5, the sixth power tube T6 is connected in parallel with the sixth diode D6, and the third power tube T3, the fourth power tube T4, the fifth power tube T5 and the sixth power tube T6 are connected in series; one end of the second inductor L2 is connected between the emitter of the fourth power tube T4 and the collector of the fifth power tube T5, and the other end is connected to the first output end or the fourth output end; The positive electrode of the sixth capacitor C6 is connected between the emitter of the third power tube T3 and the collector of the fourth power tube T4, and the negative electrode is connected between the emitter of the fifth power tube T5 and the collector of the sixth power tube T6; The positive electrode of the seventh capacitor C7 is connected to the collector of the third power tube T3, and the negative electrode is connected to the positive electrode of the eighth capacitor C8; the negative electrode of the eighth capacitor C8 is connected to the emitter of the sixth power tube T6.

[0012] Optionally, the first ACDC module and the second ACDC module have the same circuit structure and are used to convert alternating current into direct current.

[0013] Optionally, the three-phase AC input ends of the first ACDC module and the second ACDC module are respectively connected to a three-phase power grid, an independent three-phase isolation transformer or two secondary windings of an integrated three-phase split-winding transformer to provide the AC power required by each module.

[0014] The multifunctional wide voltage range battery charging and discharging device of the present invention realizes precise charging and discharging control of batteries in different voltage ranges by reasonably combining multiple ACDC modules, DCDC modules and capacitor elements. Its unique circuit design and switch configuration enable the device to stably perform charging, discharging and voltage adjustment operations in multiple working modes, ensuring high efficiency and safety during battery testing. Flexible switch control and circuit configuration not only enable the device to adapt to a wide voltage range, but also ensure the reliability and safety of the battery under different working conditions, thereby improving the accuracy and operability of the testing process. Compared with traditional devices, this device reduces costs while retaining various functions, performance parameters and applicable voltage ranges to the maximum extent, ensuring high accuracy and efficiency of battery testing.

[0015] Furthermore, the technical solution of the present invention can flexibly adjust the battery test voltage in different working modes through precise control of the logic switch, and adapt to more complex battery test requirements, such as negative voltage test items such as overcharge and overdischarge. The technical solution of the present invention enables the device to not only effectively meet the various test requirements of battery research and development, production enterprise laboratories, research institutions and testing centers, but also greatly reduce the user's comprehensive investment cost, realize the multi-purpose use of the device, and optimize the efficiency and economy of the battery testing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A circuit diagram of a multifunctional wide voltage range battery charging and discharging device according to an embodiment of the present invention is shown; Figure 2 An ACDC three-phase full-bridge two-level circuit diagram according to an embodiment of the present invention is shown; Figure 3 ACDC ANPC three-level circuit diagram according to an embodiment of the present invention is shown; Figure 4 A DCDC Buck-Boost two-level circuit diagram according to an embodiment of the present invention is shown; Figure 5 A DCDC flying capacitor three-level circuit diagram according to an embodiment of the present invention is shown; Figure 6 A high voltage range battery charge and discharge test circuit diagram according to an embodiment of the present invention is shown; Figure 7 A PACK and module battery charge and discharge test circuit diagram according to an embodiment of the present invention is shown; Figure 8 A circuit diagram of a common busbar staggered parallel battery charge and discharge test according to an embodiment of the present invention is shown; Fig. 9 A positive and negative voltage battery charge and discharge test circuit diagram according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0017] 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.

[0018] 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.

[0019] 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.

[0020] Figure 1FIG. 2 shows a circuit diagram of a multifunctional wide voltage range battery charging and discharging device according to an embodiment of the present invention. Figure 1 As shown, the multifunctional wide voltage range battery charging and discharging device comprises: The first ACDC module has a first positive output terminal connected to the positive electrode of the first capacitor C1, and a first negative output terminal connected to the negative electrode of the first capacitor C1. The second ACDC module has a second positive output terminal connected to the positive electrode of the second capacitor C2, and a second negative output terminal connected to the negative electrode of the second capacitor C2. The negative electrode of the first capacitor C1 is connected to the positive electrode of the second capacitor C2 through the first switch K1. The function of this part of the circuit is to convert alternating current into direct current through the first ACDC module and the second ACDC module, and store electrical energy through capacitors to complete the bidirectional conversion of AC-DC energy.

[0021] The first DCDC module has a first positive input terminal connected to the first positive output terminal of the first ACDC module, and a first negative input terminal connected to the first negative output terminal of the first ACDC module. Its first output terminal is output to the outside through the second switch K2, and the second output terminal is output to the outside through the third switch K3. The positive electrode of the third capacitor C3 is connected between the first output terminal and the second switch K2, and the negative electrode is connected between the second output terminal and the third switch K3. The first DCDC module further adjusts the direct current output by the first ACDC module and outputs it to the battery under test. The third capacitor C3 plays a filtering role here, reduces the current ripple, and ensures the smooth output of electric energy.

[0022] The second DCDC module, whose second positive input terminal is connected to the second positive output terminal of the second ACDC module, and the second negative input terminal is connected to the second negative output terminal of the second ACDC module. The second positive input terminal is also connected to the first positive input terminal through the fourth switch K4, and the second negative input terminal is also connected to the first negative input terminal through the fifth switch K5. The third output terminal of the second DCDC module is connected to one end of the fourth capacitor C4 through the sixth switch K6, and the fourth output terminal is connected to the other end of the fourth capacitor C4. The fourth output terminal is also output to the outside through the seventh switch K7. The fifth output terminal of the second DCDC module is output to the outside through the eighth switch K8, and is also connected to the fourth capacitor C4 through the ninth switch K9. The fourth output terminal is also connected to the first output terminal through the tenth switch K10. This part of the circuit is used to adjust the direct current output of the second ACDC module, and further optimize the current output through the fourth capacitor C4 to reduce common mode interference. The sixth switch K6, the seventh switch K7, the eighth switch K8 and the ninth switch K9 control the path of the output current to ensure adaptation to different test requirements.

[0023] The first ACDC module and the second ACDC module convert three-phase AC power into DC power, store energy through capacitors and realize bidirectional flow of energy. The first DCDC module and the second DCDC module further adjust the voltage and use switches to control the current flow direction, thereby switching different working modes to meet the needs of battery charging and discharging. Each switch (K1 to K10) adjusts the current path and output mode according to the change of working state. The circuit can support the charging and discharging test of multiple battery systems at the same time, and automatically adjusts the output voltage according to the battery voltage range to adapt to battery systems with different voltage levels. Through the series configuration of ACDC and DCDC modules, the device realizes efficient energy conversion and reduces energy loss. At the same time, the design of multiple switches enables the current path to be flexibly switched according to different test conditions. At the same time, the reasonable layout of the third capacitor C3 and the fourth capacitor C4 effectively reduces the current ripple and common mode interference, and improves the stability and accuracy of the test.

[0024] According to the above embodiments, the multifunctional wide voltage range battery charging and discharging device of the present invention realizes precise charging and discharging control of batteries in different voltage ranges by reasonably combining multiple ACDC modules, DCDC modules and capacitor elements. Its unique circuit design and switch configuration enable the device to stably perform charging, discharging and voltage adjustment operations in multiple working modes, ensuring high efficiency and safety during battery testing. Flexible switch control and circuit configuration not only enable the device to adapt to a wide voltage range, but also ensure the reliability and safety of the battery under different working conditions, thereby improving the accuracy and operability of the test process. Compared with traditional devices, this device reduces costs while retaining various functions, performance parameters and applicable voltage ranges to the maximum extent, ensuring high precision and high efficiency of battery testing.

[0025] In some embodiments, the three-phase AC input terminals of the first ACDC module and the second ACDC module are respectively connected to the two secondary windings of the three-phase power grid, the independent three-phase isolation transformer or the integrated three-phase split winding transformer, so as to provide the AC power required by each module. Through this configuration, the system can ensure stable power input, and then efficiently convert AC power into DC power for use by subsequent modules. Using a three-phase power grid as an input source can provide balanced voltage and current, reduce power fluctuations, and improve the energy efficiency and stability of the system. The independent three-phase isolation transformer and the integrated three-phase split winding transformer can provide electrical isolation and voltage regulation functions, further enhance the safety and anti-interference ability of the system, and ensure the reliable operation of the device in various power grid environments. This configuration not only improves the efficiency of energy conversion, but also enhances the adaptability of the system, and can meet the battery charging and discharging test requirements with different voltage requirements.

[0026] In some embodiments, the fourth switch K4 and the fifth switch K5 are closed or opened at the same time; the first switch K1 and the fourth switch K4 and the fifth switch K5 cannot be closed at the same time; when the fourth switch K4 and the fifth switch K5 are opened, the tenth switch K10 is also opened; the sixth switch K6 and the ninth switch K9 cannot be closed or opened at the same time. In this embodiment, the fourth switch K4 and the fifth switch K5 need to be closed or opened at the same time to ensure the correctness of the current path and prevent the current from flowing in an inappropriate path. The interlocking design of the first switch K1 and the fourth switch K4 and the fifth switch K5 is to prevent the three switches from being closed at the same time, thereby avoiding the risk of causing a short circuit of the first capacitor C1 or the second capacitor C2, and ensuring the safety of the circuit. When the fourth switch K4 and the fifth switch K5 are opened, the tenth switch K10 must also be opened to avoid the current from flowing through an unexpected path, reducing potential electrical failures and power losses. The interlocking design of the sixth switch K6 and the ninth switch K9 ensures that only one switch is closed at the same time, preventing the current from flowing in reverse or controlling conflicts, and ensuring the stable operation of the system. The second switch K2, the third switch K3, the seventh switch K7, and the eighth switch K8 are independently controlled and can flexibly connect or disconnect the circuit with the battery under test according to the test requirements, thereby achieving precise battery charge and discharge control and testing. These designs not only improve the safety and reliability of the system, but also enhance the precise control capability during the battery test process.

[0027] Figure 2 A diagram of an ACDC three-phase full-bridge two-level circuit according to an embodiment of the present invention is shown. Figure 3 FIG. 2 shows an ACDC ANPC three-level circuit diagram according to an embodiment of the present invention. Figure 2 and Figure 3 As shown, the first ACDC module and the second ACDC module can adopt Figure 2 The three-phase full-bridge two-level circuit shown, or the Figure 3 The ANPC three-level circuit shown can also use other types of ACDC conversion circuits. The main function of the above circuit is to realize the bidirectional energy conversion from AC to DC and complete the bidirectional energy flow between the power grid and the DC side. In these circuits, the switching devices can use various power electronic switching tubes such as IGBT and MOSFET with parallel diodes to meet the needs under different working conditions. In order to improve the overall performance and cost performance of the device, the first ACDC module and the second ACDC module use the same circuit structure to ensure the efficiency and stability of the device, while simplifying the design and reducing costs.

[0028] Figure 4 A DCDC Buck-Boost two-level circuit diagram according to an embodiment of the present invention is shown. Figure 5FIG. 1 shows a DCDC flying capacitor three-level circuit diagram according to an embodiment of the present invention. In some embodiments, the first DCDC module and the second DCDC module can adopt Figure 4 The Buck-Boost two-level circuit shown in the figure, or the Figure 5 The flying capacitor three-level circuit shown in the figure can also select other types of DCDC conversion circuits. The main function of the above circuit is to realize bidirectional energy conversion from DC to DC and complete the bidirectional flow of energy between the DC side and the battery under test. The switching devices in the circuit can use a variety of power electronic switching tubes such as IGBT and MOSFET with parallel diodes to ensure efficient energy conversion under different working conditions. In order to improve the overall performance and cost performance of the device, the first DCDC module and the second DCDC module adopt the same DCDC conversion circuit design, which not only ensures the consistency and stability of the device, but also simplifies the system design and reduces costs.

[0029] like Figure 4 As shown, the Buck-Boost two-level circuit diagram includes: The first power tube T1, the second power tube T2, the first diode D1, the second diode D2, the first inductor L1 and the fifth capacitor C5; the first power tube T1 is connected in parallel with the first diode D1, the second power tube T2 is connected in parallel with the second diode D2, and the first power tube T1 is connected in series with the second power tube T2; one end of the first inductor L1 is connected between the first power tube T1 and the second power tube T2, and the other end is connected to the first output end or the fourth output end; the collector of the first power tube T1 is connected to the sixth output end of the first DCDC module or the third output end of the second DCDC module, and the emitter of the second power tube T2 is connected to the second output end or the fifth output end; the positive electrode of the fifth capacitor C5 is connected to the collector of the first power tube T1, and the negative electrode is connected to the emitter of the second power tube T2. Through the above circuit, the first DCDC module and the second DCDC module can realize the boost and buck functions in different working modes, adjust the input voltage and convert it into a voltage suitable for load or battery charging and discharging. One end of the first inductor L1 is connected between T1 and T2, and the other end is connected to the first output terminal or the fourth output terminal, which plays the role of energy storage and current filtering to ensure stable current output. The fifth capacitor C5 plays a filtering role in current control, reduces current fluctuations, and improves system stability. The collector of the first power tube T1 is connected to the sixth output terminal of the first DCDC module or the third output terminal of the second DCDC module, and the emitter of the second power tube T2 is connected to the second output terminal or the fifth output terminal, forming a precise current path control. This design provides an efficient voltage regulation function, which can realize the buck-boost and buck-boost freely. At the same time, through the filtering effect of the inductor and capacitor, the current ripple is reduced, ensuring the efficiency and stability of the system.

[0030] like Figure 5 As shown, the flying capacitor three-level circuit includes: The first DCDC module and the second DCDC module include a third power tube T3, a fourth power tube T4, a fifth power tube T5, a sixth power tube T6, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a second inductor L2, a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8; the third power tube T3 is connected in parallel with the third diode D3, the fourth power tube T4 is connected in parallel with the fourth diode D4, the fifth power tube T5 is connected in parallel with the fifth diode D5, the sixth power tube T6 is connected in parallel with the sixth diode D6, and the third power tube T3, the fourth power tube T4, the fifth power tube T5 and the sixth power tube T6 are connected in series; one end of the second inductor L2 is connected between the emitter of the fourth power tube T4 and the collector of the fifth power tube T5, and the other end is connected to the first output end or the fourth output end. The positive electrode of the sixth capacitor C6 is connected between the emitter of the third power tube T3 and the collector of the fourth power tube T4, and the negative electrode is connected between the emitter of the fifth power tube T5 and the collector of the sixth power tube T6. The positive electrode of the seventh capacitor C7 is connected to the collector of the third power tube T3, and the negative electrode is connected to the positive electrode of the eighth capacitor C8; the negative electrode of the eighth capacitor C8 is connected to the emitter of the sixth power tube T6.

[0031] The third power tube T3, the fourth power tube T4, the fifth power tube T5 and the sixth power tube T6 are connected in parallel with their respective diodes (D3, D4, D5, D6) to form four parallel-series combinations to achieve voltage up and down conversion. The series design of the third power tube T3, the fourth power tube T4, the fifth power tube T5 and the sixth power tube T6 enables the circuit to efficiently switch the working mode and complete the multi-level voltage regulation function. The second inductor L2 is connected between the fourth power tube T4 and the fifth power tube T5 to play an energy storage role and filter the current, stabilize the current output, and ensure stable power supply to the load or battery. The sixth capacitor C6 further optimizes the current waveform, reduces the current ripple, and ensures stable voltage output by connecting with each power tube. The seventh capacitor C7 and the eighth capacitor C8 improve the smoothness of the current and the stability of the system by connecting in series, ensuring the efficient transmission of electric energy. This circuit configuration can achieve more precise voltage control through the combination of multi-level power tubes and capacitors, while reducing current fluctuations and ripples through filter capacitors, improving conversion efficiency and system stability. It is suitable for battery charging and discharging systems that require high stability and low ripple, especially for power systems with high voltage and high efficiency conversion.

[0032] Embodiment 1: Figure 6 FIG. 1 shows a high voltage range battery charge and discharge test circuit diagram according to an embodiment of the present invention. Figure 6 As shown, when the test voltage of the multifunctional wide voltage range battery charging and discharging device exceeds the first preset threshold value, the first switch K1, the second switch K2, the sixth switch K6 and the seventh switch K7 are closed, the positive electrode of the tested battery is connected to the first output terminal, and the negative electrode of the tested battery is connected to the fourth output terminal.

[0033] In some embodiments, the multifunctional wide voltage range battery charging and discharging device of the present invention can automatically adjust the state of the switch according to the detected battery voltage or the voltage range input by the user when testing the battery under test in the high voltage range. When the test voltage is above 1500V, the multifunctional wide voltage range battery charging and discharging device automatically closes the first switch K1, the second switch K2, the sixth switch K6 and the seventh switch K7 according to the detected battery voltage or the voltage range input by the user, and the other switches are in the open state, the positive electrode of the battery under test is connected to the first output terminal, and the negative electrode is connected to the fourth output terminal, forming a circuit as shown in FIG. Figure 6 The high voltage range battery charge and discharge test circuit shown. At this time, the DC bus voltage between the AC module and the DC module of the multifunctional wide voltage range battery charge and discharge device, that is, the sum of the voltages of the first capacitor C1 and the second capacitor C2, is the series voltage on the DC side of the first ACDC module and the second ACDC module. Under this circuit configuration, the maximum voltage of the battery under test is the sum of the highest voltage value output by the first DCDC module and the highest voltage value output by the second DCDC module, and the minimum voltage of the voltage under test is the sum of the lowest voltage value output by the first DCDC module and the lowest voltage value output by the second DCDC module. The voltage range of the battery is very wide. For example, when the voltages of the first capacitor C1 and the second capacitor C2 are both 1200V, and the duty cycle range of the first DCDC module and the second DCDC module is 10%~90%, the voltage range of the outputs of the first DCDC module and the second DCDC module is both 1200V 10%~1200V 90% = 120V~1080V, then the voltage range of the tested battery is 240V~2160V. By increasing the DC bus voltage, the voltage range of the tested battery will also increase, reaching more than 2500V. At the same time, the connection method of the third capacitor C3 and the fourth capacitor C4 minimizes the common mode effect of the positive and negative voltages of the tested battery, thereby effectively reducing the impact of common mode interference on the test results.

[0034] According to this embodiment, the multifunctional wide voltage range battery charging and discharging device can automatically adjust the switch state according to the battery voltage and usage requirements to provide an accurate voltage range, thereby ensuring the stability and reliability of the test process. At the same time, the wide voltage adjustment range enables the device to efficiently cope with the test requirements of modern high-voltage energy storage systems and adapt to the diversified applications of different battery systems. In addition, the connection method of the third capacitor C3 and the fourth capacitor C4 effectively reduces common-mode interference, thereby improving the test accuracy and reducing the negative impact of external interference during the battery test. Finally, while meeting the high-voltage test requirements, the multifunctional wide voltage range battery charging and discharging device ensures the stability and accuracy of the system through optimized design, greatly improves the test efficiency, and significantly enhances the accuracy and reliability of battery performance analysis.

[0035] Embodiment 2: Figure 7 FIG. 1 shows a PACK and a module battery charge and discharge test circuit diagram according to an embodiment of the present invention. Figure 7 As shown, when the test voltage of the multifunctional wide voltage range battery charging and discharging device is lower than the first preset threshold value and higher than the second preset threshold value, the second switch K2, the third switch K3, the seventh switch K7, the eighth switch K8 and the ninth switch K9 are closed. The positive electrode of the first tested battery is connected to the first output terminal, and the negative electrode is connected to the second output terminal; and / or, the positive electrode of the second tested battery is connected to the fourth output terminal, and the negative electrode is connected to the fifth output terminal.

[0036] In some embodiments, when the voltage of the battery under test is within the range of 150V to 1500V, the multifunctional wide voltage range battery charging and discharging device automatically closes the second switch K2, the third switch K3, the seventh switch K7, the eighth switch K8 and the ninth switch K9 by detecting the voltage of the battery under test or according to the voltage range input by the user, while keeping the other switches in the open state, forming the following Figure 7The test circuit for PACK and module batteries shown in the figure. In this configuration, the multifunctional wide voltage range battery charging and discharging device provides two independent test channels, and the test power of each channel is 50% of the power of the original multifunctional wide voltage range battery charging and discharging device, and the total test power can reach 100% of the power of the original device. This enables the device to test two groups of batteries at the same time, thereby doubling the test efficiency. The voltage range of the first tested battery is the lowest to highest voltage output by the first DCDC module, and the voltage range of the second tested battery is the lowest to highest voltage output by the second DCDC module. Assuming that the DC bus voltage is consistent with that described in the above embodiment one, the voltage range of the tested battery is 120V to 1080V. In this configuration, if the AC input side of the multifunctional wide voltage range battery charging and discharging device is equipped with two independent isolation transformers, or is directly connected to the power grid without a transformer, the multifunctional wide voltage range battery charging and discharging device can be split into two independent test systems, further improving the flexibility and applicability of the system.

[0037] According to this embodiment, by automatically adjusting the switch state, the device can flexibly adapt to the needs of different battery systems when the test battery voltage range is 150V to 1500V, and provide two independent test channels, so as to achieve simultaneous testing of two groups of batteries, greatly improving the test efficiency. At the same time, the voltage range of the device can provide a wide range of voltage regulation for different batteries through precise control of the output of the DCDC module, ensuring adaptation to a variety of energy storage systems. In addition, the device supports parallel testing of two groups of batteries while maintaining an efficient and independent working state, and can accurately distribute power during the test process, avoiding the adverse effects of uneven power distribution on the test results.

[0038] Embodiment three: In some embodiments, the two channels in the above-mentioned second embodiment can also be connected in parallel to test a single group of batteries, and the test power is 100% of the original device. Figure 8 A common busbar staggered parallel battery charge and discharge test circuit diagram according to an embodiment of the present invention is shown. Figure 8 As shown, when the two test channels of the above-mentioned embodiment 2 are connected in parallel, that is, the first output terminal is connected in parallel with the fourth output terminal, and the second output terminal is connected in parallel with the fifth output terminal to form a tested channel, it is equivalent to two independent devices running in parallel, which may have an adverse effect on the operating parameters of the device. In this case, by closing the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5, the seventh switch K7, the eighth switch K8, the ninth switch K9 and the tenth switch K10, and keeping the other switches in the open state, a test channel is formed as shown in FIG. Figure 8The common bus staggered parallel battery charge and discharge test circuit shown. At this time, the range of the tested battery voltage is the same as that of the above-mentioned embodiment 2, and the multifunctional wide voltage range battery charge and discharge device can also provide two independent test channels and support the use of channels in parallel. The maximum power of each DC output channel can reach 100% of the rated power of the multifunctional wide voltage range battery charge and discharge device, and the total power sum of the two channels is also 100% of the rated power of the multifunctional wide voltage range battery charge and discharge device, realizing the free distribution of the device power between the two channels. Due to the use of a common bus method, when the channels are connected in parallel to test a single group of batteries, the first DCDC module and the second DCDC module can be staggered in parallel, which helps to significantly reduce adverse effects such as current ripple, thereby improving the overall performance and stability of the system.

[0039] According to this embodiment, through the interlaced parallel connection of the common busbar, the multifunctional wide voltage range battery charging and discharging device can maintain the maximum power of each DC output channel at 100% of the rated power when testing a single group of batteries in parallel, and the total power of the two channels is also 100% of the rated power of the device, thereby realizing flexible power allocation. This configuration not only improves the power efficiency of the test system, but also significantly reduces adverse effects such as current ripple through interlaced parallel operation, thereby optimizing the test accuracy and stability. In addition, the technical solution of this embodiment effectively avoids the adverse parameter effects that may be caused by parallel operation, and further improves the overall performance and reliability of the device.

[0040] Embodiment 4: Fig. 9 FIG. 1 shows a positive and negative voltage battery charge and discharge test circuit diagram according to an embodiment of the present invention. Fig. 9 As shown, when the test voltage of the multifunctional wide voltage range battery charging and discharging device has a negative value, the multifunctional wide voltage range battery charging and discharging device of the present invention automatically closes the second switch K2, the fourth switch K4, the fifth switch K5, the seventh switch K7 and the ninth switch K9 according to the voltage range input by the user, and the other switches remain in the open state. At this time, one end of the battery under test is connected to the first output terminal, and the other end is connected to the fourth output terminal, forming a Fig. 9 The positive and negative voltage battery charge and discharge test circuit shown in the figure. In this configuration, the device provides a channel that can test positive and negative voltage batteries, and the test power of the channel is 100% of the rated power of the device. The test voltage range is proportional to the DC bus voltage, and the positive and negative voltages are half of the DC bus voltage. For example, when the DC bus voltage is 1200V and the operating duty cycle is between 10% and 90%, the voltage range of the battery under test is -540V to 540V. At this point, the device can perform extreme condition tests such as battery overcharge and over discharge.

[0041] According to this embodiment, the multifunctional wide voltage range battery charging and discharging device can flexibly adapt to the test requirements including negative voltage, and by automatically adjusting the switch state, provide a channel to test positive and negative voltage batteries, while ensuring that the test power of the channel is 100% of the rated power of the device. The test voltage range is proportional to the DC bus voltage, and the positive and negative voltages are each half of the DC bus voltage, ensuring efficient battery test coverage. The technical solution of this embodiment not only improves the flexibility and accuracy of the test, but also supports more complex and diverse battery test applications, ensuring that the device can provide stable and reliable test results under extreme working conditions.

[0042] According to all the above embodiments, the technical solution of the present invention can flexibly adjust the battery test voltage in different working modes through precise control of the logic switch, and adapt to more complex battery test requirements, such as negative voltage test items such as overcharge and overdischarge. The technical solution of the present invention enables the device to not only effectively meet the various test requirements of battery research and development, production enterprise laboratories, research institutions and testing centers, but also greatly reduce the user's comprehensive investment cost, realize the multi-purpose use of the device, and optimize the efficiency and economy of the battery testing process.

[0043] 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.

[0044] 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 multifunctional wide voltage range battery charging and discharging device, comprising a plurality of turn-off switches and a plurality of capacitors, characterized in that: The device comprises: A first ACDC module, wherein a first positive output terminal is connected to the positive electrode of a first capacitor C1, and a first negative output terminal is connected to the negative electrode of the first capacitor C1; A second ACDC module, wherein the second positive output terminal is connected to the positive electrode of the second capacitor C2, and the second negative output terminal is connected to the negative electrode of the second capacitor C2; the negative electrode of the first capacitor C1 is connected to the positive electrode of the second capacitor C2 through the first switch K1; A first DCDC module, wherein the first positive input terminal is connected to the first positive output terminal of the first ACDC module, and the first negative input terminal is connected to the first negative output terminal of the first ACDC module; the first output terminal thereof is output to the outside through the second switch K2, and the second output terminal thereof is output to the outside through the third switch K3; the positive electrode of the third capacitor C3 is connected between the first output terminal and the second switch K2, and the negative electrode thereof is connected between the second output terminal and the third switch K3; A second DCDC module, wherein the second positive input terminal is connected to the second positive output terminal of the second ACDC module, and the second negative input terminal is connected to the second negative output terminal of the second ACDC module; the second positive input terminal is also connected to the first positive input terminal through a fourth switch K4, and the second negative input terminal is also connected to the first negative input terminal through a fifth switch K5; The third output terminal of the second DCDC module is connected to one end of the fourth capacitor C4 through the sixth switch K6, and the fourth output terminal is connected to the other end of the fourth capacitor C4; the fourth output terminal is also output to the outside through the seventh switch K7; the fifth output terminal of the second DCDC module is output to the outside through the eighth switch K8, and is also connected to the fourth capacitor C4 through the ninth switch K9; the fourth output terminal is also connected to the first output terminal through the tenth switch K10.

2. The multifunctional wide voltage range battery charging and discharging device according to claim 1, characterized in that: The fourth switch K4 and the fifth switch K5 are closed or opened at the same time; the first switch K1 and the fourth switch K4 and the fifth switch K5 cannot be closed at the same time; when the fourth switch K4 and the fifth switch K5 are opened, the tenth switch K10 is also opened; the sixth switch K6 and the ninth switch K9 cannot be closed or opened at the same time.

3. The multifunctional wide voltage range battery charging and discharging device according to claim 2, characterized in that: When the test voltage of the multifunctional wide voltage range battery charging and discharging device exceeds a first preset threshold value, the first switch K1, the second switch K2, the sixth switch K6 and the seventh switch K7 are closed, the positive electrode of the tested battery is connected to the first output terminal, and the negative electrode of the tested battery is connected to the fourth output terminal.

4. The multifunctional wide voltage range battery charging and discharging device according to claim 3, characterized in that: When the test voltage of the multifunctional wide voltage range battery charging and discharging device is lower than the first preset threshold value and higher than the second preset threshold value, the second switch K2, the third switch K3, the seventh switch K7, the eighth switch K8 and the ninth switch K9 are closed; the positive electrode of the first tested battery is connected to the first output terminal, and the negative electrode is connected to the second output terminal; and / or, The positive electrode of the second tested battery is connected to the fourth output terminal, and the negative electrode is connected to the fifth output terminal.

5. The multifunctional wide voltage range battery charging and discharging device according to claim 4, characterized in that: When the first output end is connected in parallel with the fourth output end, and the second output end is connected in parallel with the fifth output end to form a measured channel, the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5, the seventh switch K7, the eighth switch K8, the ninth switch K9 and the tenth switch K10 are closed.

6. The multifunctional wide voltage range battery charging and discharging device according to claim 2, characterized in that: When the test voltage of the multifunctional wide voltage range battery charging and discharging device has a negative value, the second switch K2, the fourth switch K4, the fifth switch K5, the seventh switch K7 and the ninth switch K9 are closed, and one end of the battery under test is connected to the first output end, and the other end is connected to the fourth output end.

7. The multifunctional wide voltage range battery charging and discharging device according to claim 1, characterized in that: The first DCDC module and the second DCDC module include a first power tube T1, a second power tube T2, a first diode D1, a second diode D2, a first inductor L1 and a fifth capacitor C5; the first power tube T1 is connected in parallel with the first diode D1, the second power tube T2 is connected in parallel with the second diode D2, and the first power tube T1 is connected in series with the second power tube; one end of the first inductor L1 is connected between the first power tube T1 and the second power tube T2, and the other end is connected to the first output end or the fourth output end; the collector of the first power tube T1 is connected to the sixth output end of the first DCDC module or the third output end of the second DCDC module, and the emitter of the second power tube T2 is connected to the second output end or the fifth output end; the positive electrode of the fifth capacitor C5 is connected to the collector of the first power tube T1, and the negative electrode is connected to the emitter of the second power tube T2.

8. The multifunctional wide voltage range battery charging and discharging device according to claim 1, characterized in that: The first DCDC module and the second DCDC module include a third power tube T3, a fourth power tube T4, a fifth power tube T5, a sixth power tube T6, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a second inductor L2, a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8; the third power tube T3 is connected in parallel with the third diode D3, the fourth power tube T4 is connected in parallel with the fourth diode D4, the fifth power tube T5 is connected in parallel with the fifth diode D5, the sixth power tube T6 is connected in parallel with the sixth diode D6, and the third power tube T3, the fourth power tube T4, the fifth power tube T5 and the sixth power tube T6 are connected in series; one end of the second inductor L2 is connected between the emitter of the fourth power tube T4 and the collector of the fifth power tube T5, and the other end is connected to the first output end or the fourth output end; The positive electrode of the sixth capacitor C6 is connected between the emitter of the third power tube T3 and the collector of the fourth power tube T4, and the negative electrode is connected between the emitter of the fifth power tube T5 and the collector of the sixth power tube T6; The positive electrode of the seventh capacitor C7 is connected to the collector of the third power tube T3, and the negative electrode is connected to the positive electrode of the eighth capacitor C8; the negative electrode of the eighth capacitor C8 is connected to the emitter of the sixth power tube T6.

9. The multifunctional wide voltage range battery charging and discharging device according to claim 1, characterized in that: The first ACDC module and the second ACDC module have the same circuit structure and are used to convert alternating current into direct current.

10. The multifunctional wide voltage range battery charging and discharging device according to claim 9, characterized in that: The three-phase AC input ends of the first ACDC module and the second ACDC module are respectively connected to the three-phase power grid, an independent three-phase isolation transformer or two secondary windings of an integrated three-phase split-winding transformer to provide the AC power required by each module.

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