A multifunctional battery charge and discharge device with a wide voltage range

Abstract

The present invention relates to a multifunctional wide-voltage-range battery charge and discharge device, which includes a first AC-DC module and a second AC-DC module; the negative electrode of the first capacitor is connected to the positive electrode of the second capacitor through a first switch; a first DC-DC module, whose first output terminal outputs externally through a second switch, and the second output terminal outputs externally through a third switch; the positive electrode of the third capacitor is connected between the first output terminal and the second switch, and the negative electrode is connected between the second output terminal and the third switch; a second DC-DC module, whose second positive input terminal is connected to the first positive input terminal through a fourth switch, the second negative input terminal is connected to the first negative input terminal through a fifth switch, and the third output terminal is connected to one end of the fourth capacitor through a sixth switch; the fourth output terminal is connected to the other end of the fourth capacitor, and also outputs externally through a seventh switch, and is also connected to the first output terminal through a tenth switch; the fifth output terminal of the second DC-DC module outputs externally through an eighth switch, and is also connected to the fourth capacitor through a ninth switch.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly to a multifunctional wide-voltage-range battery charge and discharge device. Background Art

[0002] With the rapid development of new energy fields such as electric vehicles and electrochemical energy storage, the battery, as one of the most important core components, undertakes the key tasks of system energy storage and release. In practical applications, the battery not only needs to undergo performance tests, but also multiple tests such as safety tests and durability tests to ensure its reliability under various working conditions. Due to the diverse application scenarios of the battery, the voltage range of the battery and the system composed of the battery is very wide, which poses higher requirements for the battery test device. Therefore, battery R & D, production enterprise laboratories, research institutions, testing centers, etc. need to configure battery detection devices with different voltage ranges to meet different test requirements. However, these devices usually involve high purchase and maintenance costs. Summary of the Invention

[0003] To reduce the cost of the battery test device, some manufacturers adopt simplified schemes. For example, when testing the battery of the energy storage system, they directly use the energy storage inverter for testing, remove the DCDC part in the ACDC + DCDC two-stage topology, and only use ACDC for current control. This scheme effectively reduces the device cost and volume, but since 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 scheme is limited, and it cannot meet the test requirements of low-voltage batteries, affecting the accuracy and stability of the test. To solve this problem, some enterprises adopt the scheme of connecting the ACDC of the one-stage topology in series with the ACDC + DCDC of the two-stage topology, which not only improves the performance parameters, but also expands the control mode, and achieves a balance between cost and function. However, this scheme still has deficiencies. For example, the performance of the ACDC of the one-stage topology may affect the overall performance, and when the battery voltage is lower than the DC voltage of the ACDC, the device cannot work properly, resulting in a reduction in power output and inability to meet the high-efficiency use requirements.

[0004] To solve the above technical problems, the present invention proposes a multifunctional wide-voltage-range battery charge and discharge device, which includes:

[0005] A first ACDC module, whose first positive output terminal is connected to the positive electrode of a first capacitor C1, and whose first negative output terminal is connected to the negative electrode of the first capacitor C1;

[0006] A second AC-DC module, whose second positive output terminal is connected to the positive electrode of a second capacitor C2, and whose 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 a first switch K1;

[0007] A first DC-DC module, whose first positive input terminal is connected to the first positive output terminal of the first AC-DC module, and whose first negative input terminal is connected to the first negative output terminal of the first AC-DC module; its first output terminal outputs externally through a second switch K2, and its second output terminal outputs externally through a third switch K3; the positive electrode of a 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;

[0008] A second DC-DC module, whose second positive input terminal is connected to the second positive output terminal of the second AC-DC module, and whose second negative input terminal is connected to the second negative output terminal of the second AC-DC module; the second positive input terminal is further connected to the first positive input terminal through a fourth switch K4, and the second negative input terminal is further connected to the first negative input terminal through a fifth switch K5;

[0009] The third output terminal of the second DC-DC module is connected to one end of a fourth capacitor C4 through a sixth switch K6, and the fourth output terminal is connected to the other end of the fourth capacitor C4; the fourth output terminal also outputs externally through a seventh switch K7; the fifth output terminal of the second DC-DC module outputs externally through an eighth switch K8, and is also connected to the fourth capacitor C4 through a ninth switch K9; the fourth output terminal is further connected to the first output terminal through a tenth switch K10.

[0010] Optionally, the fourth switch K4 and the fifth switch K5 are closed or opened simultaneously; the first switch K1 cannot be closed simultaneously with the fourth switch K4 and the fifth switch K5; 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 simultaneously.

[0011] Optionally, when the test voltage of the multifunctional wide voltage range battery charging and discharging device exceeds a first preset threshold, 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.

[0012] Optionally, when the test voltage of the multi-functional 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 battery under test is connected to the first output terminal, and the negative electrode is connected to the second output terminal; and / or,

[0013] The positive electrode of the second battery under test is connected to the fourth output terminal, and the negative electrode is connected to the fifth output terminal.

[0014] Optionally, when the first output terminal and the fourth output terminal are connected in parallel, and the second output terminal and the fifth output terminal are connected in parallel to form a channel under test, 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.

[0015] Optionally, when the test voltage of the multi-functional 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 terminal, and the other end is connected to the fourth output terminal.

[0016] Optionally, the first DCDC module and the second DCDC module include a first power transistor T1, a second power transistor T2, a first diode D1, a second diode D2, a first inductor L1, and a fifth capacitor C5; the first power transistor T1 is connected in parallel with the first diode D1, the second power transistor T2 is connected in parallel with the second diode D2, and the first power transistor T1 and the second power transistor are connected in series; one end of the first inductor L1 is connected between the first power transistor T1 and the second power transistor T2, and the other end is connected to the first output terminal or the fourth output terminal; the collector of the first power transistor 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 transistor T2 is connected to the second output terminal or the fifth output terminal; the positive electrode of the fifth capacitor C5 is connected to the collector of the first power transistor T1, and the negative electrode is connected to the emitter of the second power transistor T2.

[0017] Optionally, the first DCDC module and the second DCDC module include a third power transistor T3, a fourth power transistor T4, a fifth power transistor T5, a sixth power transistor 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 transistor T3 is connected in parallel with the third diode D3, the fourth power transistor T4 is connected in parallel with the fourth diode D4, the fifth power transistor T5 is connected in parallel with the fifth diode D5, the sixth power transistor T6 is connected in parallel with the sixth diode D6, and the third power transistor T3, the fourth power transistor T4, the fifth power transistor T5, and the sixth power transistor T6 are connected in series; one end of the second inductor L2 is connected between the emitter of the fourth power transistor T4 and the collector of the fifth power transistor T5, and the other end is connected to the first output terminal or the fourth output terminal;

[0018] The positive electrode of the sixth capacitor C6 is connected between the emitter of the third power transistor T3 and the collector of the fourth power transistor T4, and the negative electrode is connected between the emitter of the fifth power transistor T5 and the collector of the sixth power transistor T6;

[0019] The positive electrode of the seventh capacitor C7 is connected to the collector of the third power transistor 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 transistor T6.

[0020] 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.

[0021] Optionally, the three-phase AC input terminals of the first ACDC module and the second ACDC module are respectively connected to a three-phase power grid, two secondary winding of an independent three-phase isolation transformer, or an integrated three-phase split-winding transformer to provide the AC power required by each module.

[0022] The multifunctional wide-voltage-range battery charge and discharge device of the present invention realizes precise charge and discharge control of batteries with different voltage ranges through reasonable combination of 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 the battery test. The 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 maximizing the retention of various functions, performance parameters, and applicable voltage ranges, ensuring high precision and high efficiency in battery testing.

[0023] Furthermore, through precise control of logic switches, the technical solution of the present invention enables the multifunctional wide-voltage-range battery charge and discharge device to flexibly adjust the battery test voltage under different working modes and adapt to more complex battery test requirements, such as negative voltage test items like overcharge and over-discharge. The technical solution of the present invention enables the device to not only effectively meet the various test requirements of battery R & D, production enterprises' laboratories, research institutions, and testing centers, but also greatly reduce the comprehensive input cost of users, realizing the multi-function of the device with one machine and optimizing the efficiency and economy of the battery test process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Shows the circuit diagram of the multifunctional wide-voltage-range battery charge and discharge device according to an embodiment of the present invention;

[0025] Figure 2 Shows the ACDC three-phase full-bridge two-level circuit diagram according to an embodiment of the present invention;

[0026] Figure 3 Shows the ACDC ANPC three-level circuit diagram according to an embodiment of the present invention;

[0027] Figure 4 Shows the DCDC Buck-Boost two-level circuit diagram according to an embodiment of the present invention;

[0028] Figure 5 Shows the DCDC flying capacitor three-level circuit diagram according to an embodiment of the present invention;

[0029] Figure 6 Shows the high-voltage-range battery charge and discharge test circuit diagram according to an embodiment of the present invention;

[0030] Figure 7 Shows the PACK and module battery charge and discharge test circuit diagram according to an embodiment of the present invention;

[0031] Figure 8 Shows the common bus interleaved parallel battery charge and discharge test circuit diagram according to an embodiment of the present invention;

[0032] Figure 9 Shows the positive and negative voltage battery charge and discharge test circuit diagram according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings. It can be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Additionally, it should be noted that for ease of description, only the parts related to the present invention rather than all the structures are shown in the drawings. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0034] The terms "comprise" and "have" in the present invention and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include steps or units not listed, or may optionally further include other steps or units inherent to these processes, methods, products, or devices.

[0035] Referring to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments may be included in at least one embodiment of the present invention. The phrase may not necessarily refer to the same embodiment when it appears in various positions in the specification, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0036] Figure 1 The circuit diagram of a multi-functional wide voltage range battery charge and discharge device according to an embodiment of the present invention is shown. As Figure 1 shown, the multi-functional wide voltage range battery charge and discharge device includes:

[0037] A first AC-DC module, whose first positive output terminal is connected to the positive electrode of a first capacitor C1, and whose first negative output terminal is connected to the negative electrode of the first capacitor C1. A second AC-DC module, whose second positive output terminal is connected to the positive electrode of a second capacitor C2, and whose 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 a first switch K1. The function of this part of the circuit is to convert alternating current into direct current through the first AC-DC module and the second AC-DC module, and store electrical energy through the capacitors to complete the bidirectional conversion of AC-DC energy.

[0038] The first DC-DC module, its first positive input terminal is connected to the first positive output terminal of the first AC-DC module, and its first negative input terminal is connected to the first negative output terminal of the first AC-DC module. Its first output terminal outputs externally through the second switch K2, and its second output terminal outputs externally 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 DC-DC module further regulates the direct current output by the first AC-DC module and outputs it to the battery under test. The third capacitor C3 plays a filtering role here, reducing the current ripple and ensuring the stable output of electrical energy.

[0039] The second DC-DC module, its second positive input terminal is connected to the second positive output terminal of the second AC-DC module, and its second negative input terminal is connected to the second negative output terminal of the second AC-DC 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 DC-DC 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 also outputs externally through the seventh switch K7. The fifth output terminal of the second DC-DC module outputs externally 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 regulate the direct current output by the second AC-DC 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.

[0040] The first AC-DC module and the second AC-DC module convert three-phase alternating current into direct current, store energy through capacitors and achieve bidirectional energy flow. The first DC-DC module and the second DC-DC module further regulate the voltage, use switches to control the current flow direction, and thus switch different working modes to meet the requirements of battery charging and discharging. Each switch (K1 to K10) adjusts the current path and output mode according to the change of the working state. This circuit can support the charging and discharging tests 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 of different voltage levels. Through the series configuration of the AC-DC and DC-DC 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, improving the stability and accuracy of the test.

[0041] According to the above embodiments, the multi-functional wide voltage range battery charge and discharge device of the present invention realizes precise charge and discharge control of batteries with 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 the battery testing process. The 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, the present device reduces costs while maximizing the retention of various functions, performance parameters and applicable voltage ranges, ensuring high precision and high efficiency of battery testing.

[0042] In some embodiments, the three-phase AC input terminals of the first ACDC module and the second ACDC module are respectively connected to the three-phase power grid, the two secondary winding terminals of an independent three-phase isolation transformer or an integrated three-phase split winding transformer, for providing 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 subsequent modules to use. Using the three-phase power grid as the input source can provide balanced voltage and current, reduce power fluctuations, and improve the energy efficiency and stability of the system. While the independent three-phase isolation transformer and the integrated three-phase split winding transformer can provide electrical isolation and voltage regulation functions, further enhancing the safety and anti-interference ability of the system, and ensuring 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 charge and discharge test requirements with different voltage requirements.

[0043] In some embodiments, the fourth switch K4 and the fifth switch K5 are closed or opened simultaneously; the first switch K1 cannot be closed simultaneously with the fourth switch K4 and the fifth switch K5; 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 simultaneously. In this embodiment, the fourth switch K4 and the fifth switch K5 need to be closed or opened simultaneously to ensure the correctness of the current path and prevent the current from flowing in an inappropriate path. The interlock design of the first switch K1 with the fourth switch K4 and the fifth switch K5 is to prevent these three switches from being closed simultaneously at the same moment, thereby avoiding the risk of short-circuiting 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 flowing through an unexpected path, reducing potential electrical faults and power losses. The interlock design of the sixth switch K6 and the ninth switch K9 ensures that only one switch is closed at the same moment, preventing the reverse flow of current or control 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 be flexibly connected or disconnected from the circuit of 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 ability during the battery testing process.

[0044] Figure 2 Fig. shows an ACDC three-phase full-bridge two-level circuit diagram according to an embodiment of the present invention. Figure 3 Fig. shows an ACDC ANPC three-level circuit diagram according to an embodiment of the present invention. As Figure 2 and Figure 3 shown, the first ACDC module and the second ACDC module can adopt the Figure 2 shown three-phase full-bridge two-level circuit, or adopt the Figure 3 shown ANPC three-level circuit, or other types of ACDC conversion circuits can also be selected. The main function of the above circuits is to achieve 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 select various power electronic switching tubes such as IGBTs and MOSFETs with parallel diodes to meet the requirements under different working conditions. To improve the overall performance and cost-effectiveness of the device, the first ACDC module and the second ACDC module adopt the same circuit structure to ensure the high efficiency and stability of the device, while simplifying the design and reducing the cost.

[0045] Figure 4 Fig. shows a DCDC Buck - Boost two-level circuit diagram according to an embodiment of the present invention. Figure 5shows 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 may adopt Figure 4 the Buck-Boost two-level circuit shown, or adopt Figure 5 the flying capacitor three-level circuit shown, and other types of DCDC conversion circuits can also be selected. The main function of the above circuit is to achieve bidirectional energy conversion from DC to DC and complete the bidirectional energy flow between the DC side and the battery under test. The switching devices in the circuit can be various power electronic switching tubes such as IGBTs and MOSFETs 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 can not only ensure the consistency and stability of the device, but also simplify the system design and reduce the cost.

[0046] As Figure 4 shown, the Buck-Boost two-level circuit diagram includes:

[0047] a first power transistor T1, a second power transistor T2, a first diode D1, a second diode D2, a first inductor L1, and a fifth capacitor C5; the first power transistor T1 is connected in parallel with the first diode D1, the second power transistor T2 is connected in parallel with the second diode D2, and the first power transistor T1 is connected in series with the second power transistor T2; one end of the first inductor L1 is connected between the first power transistor T1 and the second power transistor T2, and the other end is connected to the first output terminal or the fourth output terminal; the collector of the first power transistor 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 transistor T2 is connected to the second output terminal or the fifth output terminal; the positive electrode of the fifth capacitor C5 is connected to the collector of the first power transistor T1, and the negative electrode is connected to the emitter of the second power transistor T2. Through the above circuit, the first DCDC module and the second DCDC module can achieve 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, playing a role in energy storage and current filtering to ensure stable current output. The fifth capacitor C5 plays a filtering role in current control, reducing current fluctuations and improving system stability. The collector of the first power transistor 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 transistor T2 is connected to the second output terminal or the fifth output terminal, forming an accurate current path control. This design provides an efficient voltage regulation function, can achieve free boost and buck, and at the same time, through the filtering effect of the inductor and capacitor, reduces current ripple and ensures the efficiency and stability of the system.

[0048] As Figure 5 shown, the flying capacitor three-level circuit includes:

[0049] The first DCDC module and the second DCDC module include a third power transistor T3, a fourth power transistor T4, a fifth power transistor T5, a sixth power transistor 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 transistor T3 is connected in parallel with the third diode D3, the fourth power transistor T4 is connected in parallel with the fourth diode D4, the fifth power transistor T5 is connected in parallel with the fifth diode D5, the sixth power transistor T6 is connected in parallel with the sixth diode D6, and the third power transistor T3, the fourth power transistor T4, the fifth power transistor T5, and the sixth power transistor T6 are connected in series; one end of the second inductor L2 is connected between the emitter of the fourth power transistor T4 and the collector of the fifth power transistor T5, and the other end is connected to the first output terminal or the fourth output terminal. The positive electrode of the sixth capacitor C6 is connected between the emitter of the third power transistor T3 and the collector of the fourth power transistor T4, and the negative electrode is connected between the emitter of the fifth power transistor T5 and the collector of the sixth power transistor T6. The positive electrode of the seventh capacitor C7 is connected to the collector of the third power transistor 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 transistor T6.

[0050] The third power transistor T3, the fourth power transistor T4, the fifth power transistor T5, and the sixth power transistor T6 are connected in parallel with their respective diodes (D3, D4, D5, D6) to form four parallel-series combinations to achieve voltage step-up and step-down conversion. The series design of the third power transistor T3, the fourth power transistor T4, the fifth power transistor T5, and the sixth power transistor T6 enables the circuit to efficiently switch operating modes and complete the multi-level voltage regulation function. The second inductor L2, by being connected between the fourth power transistor T4 and the fifth power transistor T5, plays a role in energy storage and filters the current, stabilizing the current output and ensuring stable power supply to the load or battery. The sixth capacitor C6, through its connection with each power transistor, further optimizes the current waveform, reduces current ripple, and ensures stable voltage output. The seventh capacitor C7 and the eighth capacitor C8, through series connection, improve the smoothness of the current and the stability of the system, ensuring efficient power transmission. This circuit configuration, through the combination of multi-level power transistors and capacitors, can achieve more precise voltage control, and at the same time, reduces current fluctuations and ripple through filter capacitors, improving the conversion efficiency and system stability. It is suitable for battery charge and discharge systems requiring high stability and low ripple, especially for high-voltage and high-efficiency conversion power systems.

[0051] Embodiment 1:

[0052] Figure 6Shows a high-voltage range battery charge and discharge test circuit diagram according to an embodiment of the present invention. In some embodiments, as Figure 6 shown, when the test voltage of the multi-functional wide-voltage range battery charge and discharge device exceeds the first preset threshold, 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.

[0053] In some embodiments, when the multi-functional wide-voltage range battery charge and discharge device of the present invention tests a battery under test in the high-voltage range, it can automatically adjust the state of the switch according to the detected battery voltage or the voltage range input by the user. When the test voltage is above 1500V, the multi-functional wide-voltage range battery charge and discharge 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 according to the voltage range input by the user, and other switches are in the off 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 high-voltage range battery charge and discharge test circuit as Figure 6 shown. At this time, the DC bus voltage between the AC module and the DC module of the multi-functional 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. In this circuit configuration, the maximum value of the voltage of the battery under test is the sum of the highest voltage values output by the first DCDC module and the second DCDC module, and the minimum value of the voltage of the battery under test is the sum of the lowest voltage values output by the first DCDC module and 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 ranges of the first DCDC module and the second DCDC module are 10% - 90%, the voltage ranges output by the first DCDC module and the second DCDC module are both 1200V 10% - 1200V 90% = 120V - 1080V, then the voltage range of the battery under test is 240V - 2160V. By increasing the DC bus voltage, the voltage range of the battery under test will also increase and can reach above 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 electrode voltages of the battery under test, thereby effectively reducing the influence of common-mode interference on the test results.

[0054] According to this embodiment, the multi-functional wide-voltage-range battery charge and discharge 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 meet the test requirements of modern high-voltage energy storage systems and adapt to the diverse applications of different battery systems. In addition, the connection method of the third capacitor C3 and the fourth capacitor C4 effectively reduces the common-mode interference, thereby improving the test accuracy and reducing the negative impact of external interference during the battery test process. Finally, while meeting the high-voltage test requirements, the multi-functional wide-voltage-range battery charge and discharge device ensures the stability and accuracy of the system through optimized design, greatly improving the test efficiency and significantly enhancing the accuracy and reliability of battery performance analysis.

[0055] Embodiment Two:

[0056] Figure 7 It shows a PACK and module battery charge and discharge test circuit diagram according to an embodiment of the present invention. In some embodiments, as Figure 7 shown, when the test voltage of the multi-functional wide-voltage-range battery charge and discharge 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 battery under test 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 battery under test is connected to the fourth output terminal, and the negative electrode is connected to the fifth output terminal.

[0057] In some embodiments, when the voltage of the battery under test is in the range of 150V to 1500V, the multi-functional wide-voltage-range battery charge and discharge 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 other switches in the off state, forming as Figure 7The shown test circuit applicable to PACK and module batteries. In this configuration, the multi-functional wide-voltage-range battery charge and discharge device provides two independent test channels, and the test power of each channel is 50% of the power of the original multi-functional wide-voltage-range battery charge and discharge device. The total test power can reach 100% of the power of the original device. This enables the device to test two groups of batteries simultaneously, thus doubling the test efficiency. The voltage range of the first battery under test is from the lowest to the highest voltage output by the first DCDC module, and the voltage range of the second battery under test is from the lowest to the highest voltage output by the second DCDC module. Assuming that the DC bus voltage is the same as that described in the first embodiment above, the voltage range of the battery under test is from 120V to 1080V. In this configuration, if two independent isolation transformers are equipped on the AC input side of the multi-functional wide-voltage-range battery charge and discharge device, or it is directly connected to the grid without passing through a transformer, the multi-functional wide-voltage-range battery charge and discharge device can be split into two independent test systems, further enhancing the flexibility and applicability of the system.

[0058] According to this embodiment, by automatically adjusting the switch state, the device can flexibly adapt to the requirements of different battery systems when the test battery voltage range is from 150V to 1500V, and provides two independent test channels, thus enabling the simultaneous testing of two groups of batteries, greatly improving the test efficiency. At the same time, through the precise control of the output of the DCDC module, the voltage range of the device can provide a wide range of voltage regulation for different batteries, ensuring compatibility with a variety of energy storage systems. In addition, the device supports the parallel testing of two groups of batteries, while maintaining an efficient and independent working state, and can accurately distribute power during the test, avoiding adverse effects on the test results caused by uneven power distribution.

[0059] Embodiment Three:

[0060] In some embodiments, the two channels in the second embodiment above 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 Shows a common-bus interleaved parallel battery charge and discharge test circuit diagram according to an embodiment of the present invention. As Figure 8 shown, when the two test channels in the second embodiment 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 measured channel, it is equivalent to the parallel operation of two independent devices, which may have an adverse impact 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 other switches open, the formation is as Figure 8The shown common bus interleaved parallel battery charge and discharge test circuit. At this time, the range of the battery voltage to be measured is the same as that in the second embodiment above, and the multi-functional wide voltage range battery charge and discharge device can also provide two independent test channels and support parallel use of the channels. The maximum power of each DC output channel can reach 100% of the rated power of the multi-functional 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 multi-functional wide voltage range battery charge and discharge device, realizing the free distribution of the device power between the two channels. Due to the common bus method, when the channels are paralleled for testing a single group of batteries, the first DCDC module and the second DCDC module can operate in an interleaved parallel manner, which helps to significantly reduce adverse effects such as current ripple, thereby improving the overall performance and stability of the system.

[0061] According to this embodiment, through the common bus interleaved parallel method, the multi-functional wide voltage range battery charge and discharge device can maintain the maximum power of each DC output channel at 100% of the rated power and the total power sum of the two channels at 100% of the device rated power when testing a single group of batteries in parallel, realizing flexible power distribution. This configuration not only improves the power efficiency of the test system but also significantly reduces adverse effects such as current ripple through the interleaved parallel operation method, thereby optimizing the test accuracy and stability. In addition, the technical solution of this embodiment effectively avoids the adverse parameter effects that may be brought by parallel operation, further improving the overall performance and reliability of the device.

[0062] Embodiment 4:

[0063] Figure 9 Shows a positive and negative voltage battery charge and discharge test circuit diagram according to an embodiment of the present invention. In some embodiments, as Figure 9 shown, when the test voltage of the multi-functional wide voltage range battery charge and discharge device is negative, the multi-functional wide voltage range battery charge and discharge 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 rest of the switches remain in the open state. At this time, one end of the battery to be measured is connected to the first output terminal, and the other end is connected to the fourth output terminal, forming a positive and negative voltage battery charge and discharge test circuit as Figure 9 shown. In this configuration, the device provides a channel capable of testing 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 each 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 battery voltage range to be measured is -540V to 540V. At this time, the device can perform extreme condition tests such as overcharge and over-discharge of the battery.

[0064] According to this embodiment, the multi-functional wide-voltage-range battery charge and discharge device can flexibly adapt to the test requirements including negative voltage. By automatically adjusting the switch state, it provides 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 an 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.

[0065] According to all the above embodiments, through precise control of the logic switch, the multi-functional wide-voltage-range battery charge and discharge device can flexibly adjust the battery test voltage in different working modes and adapt to more complex battery test requirements, such as negative voltage test items like overcharge and over-discharge. The technical solution of the present invention enables the device to not only effectively meet the various test requirements of battery R & D, production enterprises' laboratories, research institutions and testing centers, but also greatly reduce the comprehensive input cost of users, realizing the multi-purpose use of the device and optimizing the efficiency and economy of the battery test process.

[0066] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0067] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A multi-functional wide voltage range battery charge and discharge device, comprising a plurality of turn-off switches and a plurality of capacitors, characterized in that, The device includes: A first AC-DC module, whose first positive output terminal is connected to the positive electrode of a first capacitor C1, and whose first negative output terminal is connected to the negative electrode of the first capacitor C1; A second AC-DC module, whose second positive output terminal is connected to the positive electrode of a second capacitor C2, and whose 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 a first switch K1; A first DC-DC module, whose first positive input terminal is connected to the first positive output terminal of the first AC-DC module, and whose first negative input terminal is connected to the first negative output terminal of the first AC-DC module; its first output terminal outputs externally through a second switch K2, and its second output terminal outputs externally through a third switch K3; the positive electrode of a 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; A second DC-DC module, whose second positive input terminal is connected to the second positive output terminal of the second AC-DC module, and whose second negative input terminal is connected to the second negative output terminal of the second AC-DC 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 DC-DC module is connected to the second end of a fourth capacitor C4 through a sixth switch K6, and the fourth output terminal is connected to the first end of the fourth capacitor C4; the fourth output terminal also outputs externally through a seventh switch K7; the fifth output terminal of the second DC-DC module outputs externally through an eighth switch K8, and is also connected to the second end of the fourth capacitor C4 through a ninth switch K9; the fourth output terminal is also connected to the first output terminal through a tenth switch K10; When there is a negative value in the test voltage of the multi-functional wide voltage range battery charge and discharge device, 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 terminal, and the other end is connected to the fourth output terminal.

2. The multifunctional wide voltage range battery charge and discharge device according to claim 1, wherein The fourth switch K4 and the fifth switch K5 are closed or opened simultaneously; the first switch K1 cannot be closed simultaneously with the fourth switch K4 and the fifth switch K5; 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 simultaneously.

3. The multifunctional wide voltage range battery charge and discharge device according to claim 2, characterized in that When the test voltage of the multi-functional wide voltage range battery charge and discharge device exceeds a first preset threshold, 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.

4. The multifunctional wide voltage range battery charge and discharge device according to claim 3, wherein, When the test voltage of the multi-functional wide-voltage-range battery charge and discharge 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 battery under test 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 battery under test 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 charge and discharge device according to claim 4, characterized in that, When the first output terminal and the fourth output terminal are connected in parallel, and the second output terminal and the fifth output terminal are connected in parallel to form a channel under test, 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 charge and discharge device according to claim 1, wherein, The first DCDC module and the second DCDC module include a first power transistor T1, a second power transistor T2, a first diode D1, a second diode D2, a first inductor L1, and a fifth capacitor C5; the first power transistor T1 is connected in parallel with the first diode D1, the second power transistor T2 is connected in parallel with the second diode D2, and the first power transistor T1 and the second power transistor are connected in series; one end of the first inductor L1 is connected between the first power transistor T1 and the second power transistor T2, and the other end is connected to the first output terminal or the fourth output terminal; the collector of the first power transistor 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 transistor T2 is connected to the second output terminal or the fifth output terminal; the positive electrode of the fifth capacitor C5 is connected to the collector of the first power transistor T1, and the negative electrode is connected to the emitter of the second power transistor T2.

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 third power transistor T3, a fourth power transistor T4, a fifth power transistor T5, a sixth power transistor 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 transistor T3 is connected in parallel with the third diode D3, the fourth power transistor T4 is connected in parallel with the fourth diode D4, the fifth power transistor T5 is connected in parallel with the fifth diode D5, the sixth power transistor T6 is connected in parallel with the sixth diode D6, and the third power transistor T3, the fourth power transistor T4, the fifth power transistor T5, and the sixth power transistor T6 are connected in series; one end of the second inductor L2 is connected between the emitter of the fourth power transistor T4 and the collector of the fifth power transistor T5, and the other end is connected to the first output terminal or the fourth output terminal; The positive electrode of the sixth capacitor C6 is connected between the emitter of the third power transistor T3 and the collector of the fourth power transistor T4, and the negative electrode is connected between the emitter of the fifth power transistor T5 and the collector of the sixth power transistor T6; The positive electrode of the seventh capacitor C7 is connected to the collector of the third power transistor 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 transistor T6.

8. The multifunctional wide voltage range battery charge and discharge 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.

9. The multifunctional wide-voltage-range battery charge and discharge device according to claim 8, characterized in that, The three-phase AC input terminals of the first ACDC module and the second ACDC module are respectively connected to the three-phase power grid, the two secondary winding ends of an independent three-phase isolation transformer or an integrated three-phase split-winding transformer, for providing the AC power required by each module.

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