Battery device capable of directly outputting alternating voltage

Abstract

The invention belongs to the technical field of new energy automobile batteries, and particularly relates to a battery device capable of directly outputting alternating voltage, the battery device comprises a BS1-U phase battery, a BS2-V phase battery and a BS3-W phase battery, the negative electrodes of the BS1-U phase battery, the BS2-V phase battery and the BS3-W phase battery are connected to a neutral point N; and the BS1-U phase battery, the BS2-V phase battery and the BS3-W phase battery respectively output a path of voltage. A vehicle-mounted charger and a driving inverter can be omitted when the new energy vehicle applies the system, and the weight and the cost of the whole vehicle are reduced. According to the scheme, the output port and the input port of the battery pack are three-phase alternating current ports, alternating current (AC) can be directly received, the charging process can be carried out, extra vehicle-mounted chargers and driving inverters are not needed any more, and therefore the weight and cost of the whole vehicle are reduced. The scheme can prolong the service life of the battery cell. Each battery pack in each battery segment may be selectively charged (or not charged), so each battery sub-pack may always remain balanced.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle battery technology, specifically to a battery device that can directly output AC voltage. Background Technology

[0002] New energy vehicles refer to automobiles that use unconventional vehicle fuels (such as electricity and hydrogen) as their power source, or use conventional fuels but employ new power devices, integrating advanced technologies in vehicle power control and drive, resulting in vehicles with advanced technical principles and new technologies and structures. Compared with traditional fuel vehicles, their core difference lies in the power system, with a greater emphasis on low carbon emissions, environmental protection, and energy efficiency.

[0003] New energy vehicles (especially pure electric vehicles and plug-in hybrid electric vehicles) are usually equipped with onboard chargers to facilitate charging in scenarios where there are no public charging stations (such as at home or in ordinary socket environments), and this is a common standard configuration.

[0004] like Figure 1 As shown, taking a conventional new energy vehicle as an example (not limited to new energy vehicles), it needs to be equipped with 4-on-board chargers. The power battery can only output DC voltage to 2-inverters. The DC voltage is converted into three-phase AC power by 2-inverters and then supplied to 3-motor (i.e., supplying 6-U-phase winding / 7-V-phase winding / 8-W-phase winding). 1-power battery is a whole. Inside 1-power battery, the cell units form cell modules, such as B1-cell module, B2-cell module, B3-cell module, and B4-cell module. B1-cell module and B2-cell module are connected in parallel, and cell module B3 and cell module B4 are connected in parallel, and then connected in series (this is just an example to illustrate the series and parallel structure of the cell modules inside the battery, and the actual structure is not limited to this). 4-on-board chargers are not only costly, but also increase the size and weight. Summary of the Invention

[0005] The purpose of this invention is to provide a battery device that can directly output AC voltage, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a battery device capable of directly outputting AC voltage, comprising:

[0007] BS1-U phase battery, BS2-V phase battery and BS3-W phase battery;

[0008] The negative terminals of the BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery are connected to the neutral point N.

[0009] The BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery each output one voltage, for a total of three parallel voltage outputs. These three voltages are directly supplied to the motor via three wire harnesses for power supply.

[0010] Preferably, the three voltages output by the BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery are respectively connected to the U-phase winding, V-phase winding, and W-phase winding of the motor.

[0011] Preferably, the BS1-U phase battery, BS2-V phase battery and BS3-W phase battery each include several groups of cells, and the groups of cells are connected to each other.

[0012] Preferably, the BS1-U phase battery comprises several groups of cells including cell module CU1, cell module CU2, cell module CU3, and cell module CU4, and the four groups of cells are connected by switching devices.

[0013] Preferably, the switching device includes SU1, SU2, SU3, SU4, SU5, SU6, SU7, SU8, SU9, SU10, SU11, SU12, SU13, SU14, SU15, SU16, and SU17.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] This patented technology can eliminate the need for an onboard charger in new energy vehicles, reducing overall vehicle weight and cost. The battery pack presented in this solution features three-phase AC ports for both output and input, allowing direct acceptance of AC power for charging without the need for an additional onboard charger, thus further reducing overall vehicle weight and cost.

[0016] This patent can improve the efficiency of the power system in new energy vehicles. Currently, all new energy vehicles on the market contain inverters in their power systems, and the efficiency of these systems is significantly affected by the switching losses of the inverter's power devices. Switching losses vary with drain-source voltage, switching temperature, gate resistance, current, and switching frequency. This patent can use switching devices with other / better key parameters to replace the commonly used IGBT / SiC devices, thereby achieving lower switching losses. Simultaneously, this patent can also reduce motor losses. Commercially available inverters are characterized by large voltage ripple, which is directly positively correlated with iron losses. Since this patent does not use an inverter, it modifies the battery pack and control logic to make the presented three-phase AC voltage closer to an ideal sine wave, resulting in very small voltage ripple and significantly reduced iron losses.

[0017] This design can extend cell life. Each battery pack in each segment can be selectively charged (or not charged), thus ensuring that each battery pack remains balanced at all times. Attached Figure Description

[0018] Figure 1 Diagram of existing new energy vehicle battery systems;

[0019] Figure 2 This is a diagram of the three-section AC battery in this scheme;

[0020] Figure 3 for Figure 2 A diagram showing the detailed components of a three-section AC battery.

[0021] Figure 4 The output voltage waveform of a three-segment AC battery is shown.

[0022] Figure 5 The waveform diagram of the output voltage of the U-phase battery;

[0023] Figure 6 Switching state diagram of the switching device that outputs 0 voltage for the BS1-U phase battery;

[0024] Figure 7 Switching state diagram of the switching device that outputs 1 / 4 voltage to the BS1-U phase battery;

[0025] Figure 8 Switching state diagram of the switching device that outputs 1 / 2 voltage to the BS1-U phase battery;

[0026] Figure 9 Switching state diagram of the switching device that outputs 3 / 4 voltage for the BS1-U phase battery;

[0027] Figure 10 Switching state diagram of the switching device that outputs Umax voltage for the BS1-U phase battery;

[0028] Figure 11 Switching state diagram of the switching device that outputs -1 / 4 voltage for the BS1-U phase battery;

[0029] Figure 12 Switching state diagram of the switching device that outputs -1 / 2 voltage for the BS1-U phase battery;

[0030] Figure 13 Switching state diagram of the switching device that outputs -3 / 4 voltage for the BS1-U phase battery;

[0031] Figure 14 Switching state diagram of the switching device that outputs -Umax voltage for the BS1-U phase battery;

[0032] Figure 15This is a diagram of the control signals for the BS1-U phase battery switching device. These control signals are used for... Figure 16 Simulation model;

[0033] Figure 16 The output voltage of the BS1-U phase battery is shown in the MATLAB simulation model diagram.

[0034] Figure 17 Output voltage diagram of MATLAB simulation model of BS1-U phase battery output voltage;

[0035] Figure 18 The output voltage THD analysis diagram for the BS1-U phase battery is shown below.

[0036] Figure 19 The output voltage simulation model diagram of SVPWM control in MATLAB is shown below;

[0037] Figure 20 The output voltage waveform diagram for SVPWM control;

[0038] Figure 21 This is a diagram showing the THD analysis of the output voltage of SVPWM control. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] Example 1:

[0042] Please see Figure 1-21 The present invention provides a technical solution: a battery device that can directly output AC voltage, comprising: BS1-U phase battery, BS2-V phase battery and BS3-W phase battery;

[0043] The negative terminals of the BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery are connected to the neutral point N. Each of the BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery outputs one voltage, resulting in a total of three parallel voltage outputs. These three voltages are directly supplied to the motor via three wiring harnesses. The three voltages output from the BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery are respectively connected to the U-phase winding, V-phase winding, and W-phase winding of the motor.

[0044] Analysis of the above content: such as Figure 2 As shown, the power battery is divided into three parallel battery segments (three segments are just an example; other numbers of segments are also included): BS1 - U-phase battery, BS2 - V-phase battery, and BS3 - W-phase battery. The negative terminals of the three battery segments are connected together, i.e., neutral point N. Each battery segment outputs one voltage, and the three battery segments output three parallel voltages. These three voltages are directly supplied to the three-phase windings of the motor (6 - U-phase winding, 7 - V-phase winding, 8 - W-phase battery) via three wiring harnesses.

[0045] Example 2:

[0046] Please see Figure 1-21 The present invention provides a technical solution:

[0047] The BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery each include several groups of cells (this embodiment uses four groups as an example for illustration), and the four groups of cells are connected to each other; the four groups of cells of the BS1-U phase battery include cell module CU1, cell module CU2, cell module CU3, and cell module CU4, and the four groups of cells are connected to each other through switching devices; the switching devices include SU1, SU2, SU2, SU3, SU4, SU5, SU6, SU7, SU8, SU9, SU10, SU11, SU12, SU13, SU14, SU15, SU16, and SU17.

[0048] Analysis of the above content: such as Figure 3 As shown, 1-power battery (1-power battery refers to...) Figure 3In the attached diagram, reference 1 represents the power battery (different references in other diagrams represent different aspects). The battery is divided into three parallel battery segments: BS1 (U-phase battery), BS2 (V-phase battery), and BS3 (W-phase battery). A detailed topology diagram of the power battery (1) is provided, and an AC charging port (5) is also included. Each battery segment is further divided into four groups of cell modules (four groups are used here as an example, but are not limited to other numbers). Taking the BS1-U-phase battery as an example, the cells are divided into four groups: cell module CU1, cell module CU2, cell module CU3, and cell module CU4. Cell modules can be connected in parallel, in series, or in a mixed series-parallel configuration. The series and parallel connection status between cell modules is controlled by switching devices. Taking the BS1-U phase battery as an example, the switching devices controlling the series and parallel connection status of the cell modules are SU1, SU2, SU3, SU4, SU5, SU6, SU7, SU8, SU9, SU10, SU11, SU12, SU13, SU14, SU15, SU16, and SU17. The topology of the BS1-U phase battery and the BS2-V phase battery B is the same as that of the BS1-U phase battery (their connection method is as follows). Figure 3 (As shown). Figure 3 The battery internal switching device topology shown is only an example to illustrate that battery cells can be connected in series and parallel through switching devices, but the present invention is not limited to this topology.

[0049] The negative terminals of the three battery segments are connected together, forming the neutral point N. Each battery segment outputs one voltage, resulting in three parallel voltage outputs. These three voltages are directly supplied to the three-phase windings of motor 3 (6-U phase winding, 7-V phase winding, 8-W phase winding) via three wiring harnesses. The 5-AC charging port is used for charging the vehicle at an AC charging station. Figure 1 Compared to conventional new energy vehicles, the 4-on-board charger and inverter are not present. Instead, the 3-motor windings (6-U-phase winding, 7-V-phase winding, 8-W-phase winding) and switching devices are used to replace the functions of the 4-on-board charger.

[0050] exist Figure 4 In the diagram, three parallel battery segments output three-phase voltages. The vertical axis represents the output voltage, and the horizontal axis represents time. The intersection of the vertical and horizontal axes, O, marks the start time of the waveform, i.e., t = 0. The BS1-U phase battery generates... Figure 4 The output voltage of the U-phase battery and the generation of the BS2-V phase battery Figure 4 The output voltage of the V-phase battery and the generation of the BS3-W-phase battery are shown. Figure 3The output voltage of phase W is shown. The three phase voltages (UV, V, and W) have identical waveforms with a period of T, but a phase difference of T / 3. For example, the output voltage of phase V lags behind the output voltage of phase U by T / 3, and vice versa. Only the waveform for one period T is given here; waveforms for other time intervals are not shown, but can be deduced from the periodicity of the waveforms.

[0051] exist Figure 5 In this diagram, the output voltage of the U-phase battery is presented separately to better describe the battery output waveform. Assuming the amplitude voltage Umax of the U-phase battery output is 1, the output voltage increases in a stepped manner within the time interval [0, T / 4]: 0, 1 / 4, 1 / 2, 3 / 4, 1; decreases in a stepped manner within the time interval [T / 4, T / 2]: 1, 3 / 4, 1 / 2, 1 / 4, 0; decreases in a stepped manner within the time interval [T / 2, 3T / 4]: 0, -1 / 4, -1 / 2, -3 / 4, -1; and increases in a stepped manner within the time interval [3T / 4, T]: -1, -3 / 4, -1 / 2, -1 / 4, 0. The waveforms for other time intervals can be derived periodically.

[0052] Battery segmentation. For example... Figure 2 As shown, the power battery is divided into three parallel battery segments (these three segments are for illustrative purposes only; the number of segments can be adjusted according to the actual load): BS1 - U-phase battery, BS2 - V-phase battery, BS3 - W-phase battery. The negative terminals of the three battery segments are connected together, forming the neutral point N. Each battery segment outputs one voltage, resulting in three parallel voltage outputs that directly supply the three-phase windings of the motor (6 - U-phase winding, 7 - V-phase winding, 8 - W-phase battery).

[0053] The cells inside each battery segment are grouped together. For example... Figure 3 As shown, each battery segment is divided into four groups of cell modules (the division into four groups is for illustrative purposes only; the number of groups can be adjusted according to actual needs). Taking the BS1-U phase battery as an example, the cells are divided into four groups: CU1 - cell module, CU2 - cell module, CU3 - cell module, and CU4 - cell module.

[0054] Series-parallel switching between battery cell modules. For example... Figure 3 As shown, the series and parallel connection status between cell modules is controlled by switching devices. Taking the BS1-U phase battery as an example, the switching devices controlling the series and parallel connection status of the cell modules are SU1, SU2, SU3, SU4, SU5, SU6, SU7, SU8, SU9, SU10, SU11, SU12, SU13, SU14, SU15, SU16, and SU17. The topology of the BS1-U phase battery and the BS2-V phase battery B is the same as that of the BS1-U phase battery. Figure 3 The battery internal switching device topology shown is just an example to illustrate that battery cells can be connected in series and parallel through switching devices. The topology can be changed according to actual needs.

[0055] The BS1-U phase battery outputs 0 voltage. Figure 6 Taking the BS1-U phase battery as an example, the control system (which is not a highly relevant component in this invention and is therefore omitted from the diagram) provides a control signal to keep all switching devices (SU1, SU2, SU3, SU4, SU5, SU6, SU7, SU8, SU9, SU10, SU11, SU12, SU13, SU14, SU15, SU16, SU17) in the off state. The 6-U phase winding is disconnected from the CU1-cell module, CU2-cell module, CU3-cell module, and CU4-cell module by the switching devices. Therefore, the voltage on the 6-U phase winding is 0, meaning the BS1-U phase battery outputs 0 voltage. The output voltage of the BS1-U phase battery is as follows: Figure 5 As shown, the voltage on the vertical axis is 0 for the corresponding time interval [t0, t1].

[0056] The BS1-U phase battery outputs 1 / 4 voltage. Figure 7 Taking the BS1-U phase battery as an example, the control system's control switches (SU1, SU2, SU3, SU4, SU5, SU6, SU11, SU12, SU13, SU14) are in the ON state, while the control switches (SU7, SU8, SU9, SU10, SU15, SU16, SU17) are in the OFF state. The cell modules are connected in parallel: CU1-cell module || CU2-cell module || CU3-cell module || CU4-cell module (using "||" to represent parallel relationships and "==" to represent series relationships). Therefore, the voltage on the 6-U phase winding is 1 / 4, meaning the BS1-U phase battery outputs 1 / 4 of its voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the voltage on the vertical axis corresponds to the time interval [t1, t2], which is 1 / 4.

[0057] The BS1-U phase battery outputs 1 / 2 voltage. Figure 8Taking the BS1-U phase battery as an example, the control system's control switches (SU1, SU2, SU4, SU5, SU6, SU8, SU12, SU14, SU16) are in the ON state, while the control switches (SU3, SU7, SU9, SU10, SU11, SU13, SU15, SU17) are in the OFF state. The cell modules are in a series-parallel connection: (CU1-cell module || CU2-cell module) == (CU3-cell module || CU4-cell module). Therefore, the voltage on the 6-U phase winding is 1 / 2, meaning the BS1-U phase battery outputs 1 / 2 voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the voltage on the vertical axis corresponds to the time interval [t3, t4], which is 1 / 2.

[0058] The BS1-U phase battery outputs 3 / 4 voltage. Figure 9 Taking the BS1-U phase battery as an example, the control system's control switches (SU1, SU2, SU4, SU6, SU8, SU14, SU16, SU17) are in the ON state, while the control switches (SU3, SU5, SU7, SU9, SU10, SU11, SU12, SU13, SU15) are in the OFF state. The cell modules are in a series-parallel connection: (CU1-cell module || CU2-cell module) == CU3-cell module == CU4-cell module). Therefore, the voltage on the 6-U phase winding is 3 / 4, meaning the BS1-U phase battery outputs 3 / 4 of its voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the voltage on the vertical axis corresponds to the time interval [t3, t4], which is 3 / 4.

[0059] The BS1-U phase battery outputs the maximum voltage Umax. Figure 10 Taking the BS1-U phase battery as an example, the control system's control switches (SU2, SU4, SU6, SU7, SU15, SU16, SU17) are in the ON state, and the control switches (SU1, SU3, SU5, SU8, SU9, SU10, SU11, SU12, SU13, SU14) are in the OFF state. The cell modules are connected in series: CU1-cell module == CU2-cell module == CU3-cell module == CU4-cell module. Therefore, the voltage on the 6-U phase winding is Umax = 1, meaning the BS1-U phase battery outputs a voltage of Umax. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the corresponding time interval is [t4, t6], and the voltage on the vertical axis is Umax.

[0060] The BS1-U phase battery outputs 3 / 4 voltage. The BS1-U phase battery output voltage is as follows: Figure 5As shown, the corresponding time interval [t6, t7] is symmetrical to [t3, t4] about the axis t = π / 4 (this symmetry is for ease of understanding; in actual use, the waveform of one cycle will no longer exhibit symmetry due to changes in rotational speed, voltage, and other conditions). The vertical axis represents voltage 3 / 4. The control system controls the switching state of the switching devices, such as... Figure 9 As shown.

[0061] The BS1-U phase battery outputs 1 / 2 voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the corresponding time interval [t7, t8] is symmetrical to [t2, t3] about the t = π / 4 axis, and the vertical axis represents the voltage (1 / 2). The control system controls the switching state of the switching devices, as shown... Figure 8 As shown.

[0062] The BS1-U phase battery outputs 1 / 4 voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the corresponding time interval [t8, t9] is symmetrical to [t1, t2] about the t = π / 4 axis, and the vertical axis represents the voltage (1 / 4). The control system controls the switching state of the switching devices, as shown... Figure 7 As shown.

[0063] The BS1-U phase battery outputs 0 voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the corresponding time interval [t9, t11] is symmetrical to [t0, t1] about the t = π / 4 axis, with the voltage on the vertical axis being 0. The control system controls the switching state of the switching devices, as follows: Figure 6 As shown.

[0064] exist Figure 4 In the figure, the waveforms of the BS1-U phase battery, BS2-V phase battery and BS3-W phase battery are only given for one period T. According to the periodicity of the function, the waveforms of other intervals can be derived.

[0065] The BS1-U phase battery outputs -1 / 4 voltage. Figure 11 Taking the BS1-U phase battery as an example, the control system's control switches (SU1, SU2, SU3, SU4, SU5, SU9, SU10, SU12, SU13, SU14) are in the ON state, while the control switches (SU6, SU7, SU8, SU11, SU15, SU16, SU17) are in the OFF state. The cell modules are connected in parallel: CU1-cell module || CU2-cell module || CU3-cell module || CU4-cell module (using "||" to represent parallel relationships and "==" to represent series relationships). Therefore, the voltage on the 6-U phase winding is -1 / 4, meaning the BS1-U phase battery outputs a -1 / 4 voltage. The BS1-U phase battery output voltage is as follows: Figure 5As shown, the corresponding time interval [t11, t12] has a vertical axis voltage of 1 / 4.

[0066] The BS1-U phase battery outputs -1 / 2 voltage. Figure 12 Taking the BS1-U phase battery as an example, the control system's control switches (SU1, SU2, SU4, SU5, SU9, SU10, SU12, SU14, SU16) are in the ON state, while the control switches (SU3, SU6, SU7, SU8, SU11, SU13, SU15, SU17) are in the OFF state. The cell modules are in a series-parallel connection: (CU1-cell module || CU2-cell module) == (CU3-cell module || CU4-cell module). Therefore, the voltage on the 6-U phase winding is -1 / 2, meaning the BS1-U phase battery outputs a -1 / 2 voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the corresponding time interval [t12, t13] has a voltage of -1 / 2 on the vertical axis.

[0067] The BS1-U phase battery outputs -3 / 4 voltage. Figure 13 Taking the BS1-U phase battery as an example, the control system's control switches (SU1, SU2, SU4, SU9, SU10, SU14, SU16, SU17) are in the ON state, while the control switches (SU3, SU5, SU6, SU7, SU8, SU11, SU12, SU13, SU15) are in the OFF state. The cell modules are in a series-parallel connection: (CU1-cell module || CU2-cell module) == CU3-cell module == CU4-cell module). Therefore, the voltage on the 6-U phase winding is -3 / 4, meaning the BS1-U phase battery outputs a -3 / 4 voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the corresponding time interval [t13, t14] has a voltage of -3 / 4 on the vertical axis.

[0068] BS1-U phase battery output -Umax voltage. Figure 14 Taking the BS1-U phase battery as an example, the control system's control switches (SU2, SU4, SU9, SU10, SU15, SU16, SU17) are in the ON state, while the control switches (SU1, SU3, SU5, SU6, SU7, SU8, SU11, SU12, SU13, SU14) are in the OFF state. The cell modules are connected in series: CU1-cell module == CU2-cell module == CU3-cell module == CU4-cell module. Therefore, the voltage on the 6-U phase winding is -Umax = -1, meaning the BS1-U phase battery outputs a -Umax voltage. The BS1-U phase battery output voltage is as follows: Figure 5As shown, the corresponding time interval is [t14, t16], and the voltage on the vertical axis is -Umax.

[0069] The BS1-U phase battery outputs -3 / 4 voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the corresponding time interval [t16, t17] is symmetrical to [t13, t14] about the axis of t = 3π / 4, and the voltage on the vertical axis is -3 / 4. The control system controls the switching state of the switching devices, as shown... Figure 13 As shown. The BS1-U phase battery outputs -1 / 2 voltage. The BS1-U phase battery output voltage is as follows. Figure 5 As shown, the corresponding time interval [t17, t18] is symmetrical to [t12, t13] about the axis of t = 3π / 4, and the voltage on the vertical axis is -1 / 2. The control system controls the switching state of the switching devices, as shown... Figure 12 As shown.

[0070] The BS1-U phase battery outputs -1 / 4 voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the corresponding time interval [t18, t19] is symmetrical to [t11, t12] about the t = 3π / 4 axis, and the voltage on the vertical axis is -1 / 4. The control system controls the switching state of the switching devices, as follows: Figure 11 As shown.

[0071] The BS1-U phase battery outputs 0 voltage. The BS1-U phase battery output voltage is as follows: Figure 5 As shown, the corresponding time interval [t19, t20] is symmetrical to [t10, t11] about the t = 3π / 4 axis, with the voltage on the vertical axis being 0. The control system controls the switching state of the switching devices, as shown... Figure 10 As shown.

[0072] BS2-V phase battery output voltage as follows Figure 4 As shown, the output voltage waveform of the BS2-V phase battery is the same as that of the BS1-U phase battery, but its voltage phase lags behind the BS1-U phase battery voltage waveform by T / 3.

[0073] BS3-W phase battery output voltage as follows Figure 4 As shown, the output voltage waveform of the BS3-W phase battery is the same as that of the BS2-V phase battery, but its voltage phase lags behind the BS2-V phase battery voltage waveform by T / 3.

[0074] The specific application of this solution is as follows.

[0075] Application Example 1: Application of AC Battery System in Pure Electric Passenger Vehicles

[0076] In the field of pure electric passenger vehicles, the smoothness of the powertrain, the stability of the driving range, and the charging compatibility are core technical requirements. Based on the battery device of this invention that can directly output AC voltage, problems such as inverter losses and complex charging systems in traditional passenger vehicle powertrains can be specifically addressed. Its specific application configuration and operating mechanism are as follows:

[0077] System Configuration

[0078] The battery pack for this pure electric passenger vehicle consists of three independent phase battery groups: BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery. Each phase battery group comprises four cell modules. Specifically, the BS1-U phase battery includes cell modules CU1, CU2, CU3, and CU4; the BS2-V phase battery includes cell modules CV1, CV2, CV3, and CV4; and the BS3-W phase battery includes cell modules CW1, CW2, CW3, and CW4. Each cell module consists of 12 lithium iron phosphate cells with a rated voltage of 3.7V connected in series. The rated voltage of a single module is 44.4V, and the rated capacity is 80Ah.

[0079] The negative terminals of the three battery groups are connected to the neutral point N via copper busbars, forming a star topology. Each battery cell module is connected via dedicated high-voltage switching devices. The BS1-U phase batteries are equipped with 17 switching devices (SU1-SU17), the BS2-V phase batteries with SV1-SV17, and the BS3-W phase batteries with SW1-SW17. All switching devices use IGBT relays with a withstand voltage of 600V, on-resistance ≤5mΩ, and response time ≤10μs, meeting high-frequency switching requirements.

[0080] The output of the device is directly connected to the U-phase, V-phase, and W-phase windings of the passenger vehicle drive motor via three high-voltage wire harnesses. The motor is a three-phase asynchronous motor with a rated power of 150kW and a rated voltage of 380V, and is compatible with three-phase AC input.

[0081] Power supply operation mechanism

[0082] After the vehicle starts, the vehicle controller calculates the real-time power required by the motor based on the accelerator pedal signal and the vehicle speed signal, generates a three-phase AC voltage command, and sends it synchronously to the control system of the battery device.

[0083] During low-speed driving (vehicle speed ≤ 60km / h): The motor requires a lower voltage, at which point the BS1-U phase battery needs to output half of its rated voltage (22.2V). The control system controls switches SU1, SU2, SU4, SU5, SU6, SU8, SU12, SU14, and SU16 to be in the ON state, while the remaining switches are OFF. At this time, CU1 and CU2 are connected in parallel (total voltage 44.4V), and CU3 and CU4 are connected in parallel (total voltage 44.4V). These two parallel circuits are then connected in series, outputting 88.8V (i.e., half the total voltage, which is 177.6V from the four series circuits). The BS2-V phase battery and the BS3-W phase battery respond synchronously, lagging behind the BS1-U phase battery by 120° and 240° respectively, outputting voltages of the same amplitude, forming a symmetrical three-phase AC power supply that directly drives the motor.

[0084] During high-speed operation (vehicle speed > 60km / h): The motor's power demand increases, requiring an output Umax voltage (177.6V). The control system adjusts the switching status of the BS1-U phase batteries, turning on SU2, SU4, SU6, SU7, SU15, SU16, and SU17, while turning off the others; at this time, the four modules CU1, CU2, CU3, and CU4 are connected in series, with a total voltage of 177.6V. The BS2-V phase and BS3-W phase batteries synchronously switch to the series state, and the three-phase voltage amplitude increases synchronously to meet the power demand of the motor at high speed.

[0085] Braking feedback phase: When the vehicle brakes, the motor switches to generator mode, and the generated AC power is fed back to the battery through the windings. The control system monitors the SOC (State of Charge) of each group of battery cells in real time. If the SOC of the CU1 module is 75% (lower than the average of 80%), the corresponding switches such as SU1 and SU2 are turned on individually, so that the CU1 module can receive feedback power first. If the SOC of the CV3 module has reached 95% (higher than the average), its corresponding switches SV5 and SV6 are turned off to stop receiving power, ensuring that the SOC deviation of each group of modules is always controlled within 5%.

[0086] Charging operation mechanism

[0087] This device supports direct connection to a 220V / 380V AC mains for charging, eliminating the need for an additional vehicle charger. During charging, the AC charging port is connected to the motor windings via a high-voltage wiring harness. The windings act as inductors in the rectification process, and the battery device's control system manages the charging process by adjusting the states of the switching devices.

[0088] After connecting to a 380V three-phase AC charging pile, the control system controls the switching devices of the three phase batteries to alternately turn on according to the grid voltage waveform: during the positive half-cycle of the U-phase grid voltage, switches such as SU1 and SU3 of the BS1-U phase batteries are turned on, allowing modules CU1-CU4 to receive power through the U-phase winding; during the positive half-cycle of the V-phase voltage, switches such as SV2 and SV4 of the BS2-V phase batteries are turned on, charging through the V-phase winding; the same applies to the W phase. During the charging process, the voltage of each module is checked every 5 minutes. When the voltage of a module reaches 4.2V (full charge voltage), its corresponding switching device is immediately turned off, stopping charging, until all modules reach full charge.

[0089] Technical benefits: When applied to pure electric passenger vehicles, this device reduces the motor input voltage ripple coefficient from 8% in traditional systems to below 3% by eliminating the inverter, and reduces iron losses by approximately 15%; independent charge and discharge control of the battery cell modules increases battery cycle life from 1200 cycles to over 1500 cycles; the direct AC charging mode is compatible with various power grid environments, and the energy conversion efficiency during the charging process remains above 92%, meeting the stability and reliability requirements of daily use in passenger vehicles.

[0090] Application Example 2: Application of AC Battery System in Pure Electric Buses

[0091] Pure electric buses are characterized by large passenger capacity, long operating time, and frequent start-stop operations, placing stringent requirements on the power output stability, continuous operating capability, and ease of maintenance of the battery device. The battery device of this invention can be adapted to the needs of buses through modular design, and its specific applications are as follows:

[0092] System Configuration

[0093] The battery pack for this pure electric bus uses a three-phase parallel topology. Each of the three phase batteries (BS1-U, BS2-V, and BS3-W) contains six cell modules (compared to four modules in traditional passenger vehicles to increase capacity). The cell modules in each phase battery pack are of the same model. The BS1-U phase battery pack includes CU1-CU6, and each module consists of 16 ternary lithium battery cells with a rated voltage of 3.2V connected in series. Each module has a rated voltage of 51.2V and a rated capacity of 120Ah. The negative terminals of the three phase batteries are connected to the neutral point N via a busbar with a current carrying capacity of ≥500A.

[0094] In terms of switching devices, each phase cell is equipped with 21 dedicated high-voltage switches (SU1-SU21, SV1-SV21, SW1-SW21), which adopt SiC MOSFET switches with a withstand voltage of 1200V and a rated current of 200A. The conduction loss is ≤0.1W, and it supports high-frequency switching (≥10kHz) to adapt to the frequent start-stop conditions of buses.

[0095] The battery unit output is connected to the bus drive motor via four high-voltage wires (including one shielded wire). The motor is a permanent magnet synchronous motor with a rated power of 300kW and a rated voltage of 550V, supporting a wide voltage input (300-600V).

[0096] Power supply operation mechanism

[0097] After the bus starts, the battery unit dynamically adjusts the output voltage according to the instructions of the motor controller.

[0098] During the initial stage: The motor requires high torque output, demanding a voltage of 300V. At this time, the BS1-U phase battery controls the switching devices SU1, SU3, SU5, and SU7 to turn on, making CU1 and CU2 in parallel (51.2V), CU3 and CU4 in parallel (51.2V), and CU5 and CU6 in parallel (51.2V). These three parallel circuits are then connected in series, resulting in a total voltage of 153.6V. The BS2-V phase and BS3-W phase batteries synchronously output voltages of the same amplitude, with a phase difference of 120°. The combined three-phase voltage meets the starting torque requirements.

[0099] During constant speed driving (vehicle speed 50km / h): The motor's power demand is stable, and the voltage is adjusted to 450V. The BS1-U phase battery switching switch states, causing CU1-CU3 to be connected in series (51.2V×3=153.6V) and CU4-CU6 to be connected in series (153.6V). The two series circuits are then connected in series again, resulting in a total voltage of 307.2V. The BS2-V phase and BS3-W phase batteries are adjusted synchronously, increasing the three-phase voltage amplitude and ensuring that the motor input power remains stable at 150kW.

[0100] Station entry and stop phase: When the bus enters the station, it needs to frequently decelerate and stop. During this time, the battery device enters dynamic adjustment mode. During deceleration, the AC power fed back from the motor is input to the battery device through the windings. The control system selectively charges according to the SOC of each module (set threshold 70%-90%): if the SOC of the CU4 module is 72%, its corresponding switches SU12 and SU13 are turned on to prioritize receiving power; if the SOC of the CV6 module has reached 89%, SV19 and SV20 are turned off to avoid overcharging. When starting to leave the station, the switching devices complete the state switching from charging to discharging within 10ms to ensure no power delay.

[0101] Charging operation mechanism

[0102] The buses adopt a centralized charging mode, and after returning to the depot at night, they are connected to a 600V three-phase AC charging pile. The charging process is controlled by the battery management system (BMS) throughout.

[0103] During charging, the AC charging port is connected to the three-phase input terminals of the battery pack via a dedicated charging gun. The BMS generates switching control signals based on the grid voltage waveform (50Hz sine wave): at the peak of the U-phase voltage (311V), switches SU2, SU4, and SU6 of the BS1-U phase batteries are turned on, allowing modules CU1-CU6 to receive power through the U-phase winding; at the peak of the V-phase and W-phase voltages, the switching devices of the BS2-V phase and BS3-W phase batteries are turned on respectively. During charging, the BMS checks the module temperature every 2 minutes. When the temperature of a module exceeds 45℃, its charging current is reduced (from 100A to 60A), and the liquid cooling system is activated to ensure that the temperature of all modules is maintained between 25-40℃.

[0104] Technical Performance: When applied to pure electric buses, this device, through the series-parallel switching of multiple battery cell modules, enables a voltage output range covering 300-600V, adapting to the wide voltage requirements of the motor; the low-loss characteristics of SiC switching devices reduce switching losses by 40% compared to traditional IGBTs, increasing the power system efficiency to 94%; independent charge and discharge control of the modules ensures that the battery can still achieve a cycle life of over 1000 cycles under high-intensity operating conditions of 16 hours per day, meeting the service life requirement of buses for more than 3 years.

[0105] Application Example 3: Application of AC Battery System in Electric Excavators

[0106] Electric excavators, as an important category of construction machinery, are characterized by large load fluctuations and complex operating environments (high temperature, vibration), placing extremely high demands on the battery device's shock resistance, voltage stability, and rapid response capabilities. The battery device of this invention, through enhanced structural design and dynamic adjustment algorithms, can adapt to these operational requirements. Specific applications are as follows:

[0107] System Configuration

[0108] The battery unit of this electric excavator adopts a three-phase battery star connection. Each of the BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery contains 5 cell modules. Each module uses lithium titanate battery cells (long cycle life and excellent low temperature performance). The BS1-U phase battery includes CU1-CU5. Each module consists of 20 lithium titanate battery cells with a rated voltage of 2.4V connected in series. The rated voltage of a single module is 48V, the rated capacity is 150Ah, and it supports 10C rate discharge (short-time high current output).

[0109] The negative terminals of the three phase batteries are connected to the neutral point N via an elastic connection structure (including shock-absorbing rubber) to accommodate vibrations during excavator operation (amplitude ≤ 5mm). The switching devices utilize military-grade high-voltage relays, with each phase battery equipped with 19 switches (SU1-SU19, SV1-SV19, SW1-SW19), a withstand voltage of 800V, a rated current of 300A, and a vibration resistance rating of IP6K9K, enabling stable operation in environments ranging from -40℃ to 85℃.

[0110] The battery unit output is connected to the excavator drive motor (main pump motor) via an armored high-voltage wiring harness. The motor is a three-phase asynchronous motor with a rated power of 200kW and a rated voltage of 400V, and supports short-term overload (150% rated power for 30 seconds).

[0111] Power supply operation mechanism

[0112] When the excavator is in operation, the battery device adjusts the output voltage in real time according to the load changes of the hydraulic system (such as digging, rotating, and lifting actions).

[0113] Excavation operation phase (heavy load): The main pump motor requires a power of 300kW (150% overload) and needs to output 400V voltage. The BS1-U phase battery controls the switching devices SU2, SU5, SU8, and SU11 to turn on, causing CU1-CU5 to be connected in series (48V×5=240V); the BS2-V phase and BS3-W phase batteries synchronously output 240V voltage. The three-phase combined voltage meets the heavy load requirements. At this time, the switching devices are cooled by forced air (airflow ≥50m³ / h). 3 ( / h) Maintain temperature ≤70℃.

[0114] During the rotating operation phase (medium load): the motor power is reduced to 150kW, and the voltage is adjusted to 280V. The BS1-U phase battery switching switch status enables CU1-CU2 to work in series (96V), CU3-CU4 to work in series (96V), and CU5 to work independently (48V), with the three circuits connected in series and a total voltage of 240V; the BS2-V phase and BS3-W phase batteries are adjusted synchronously to ensure three-phase voltage balance and reduce motor harmonic losses.

[0115] During idling (no operation): the motor power drops to 50kW and the voltage drops to 120V. The BS1-U phase battery controls CU1 and CU2 in parallel (48V), and the other modules are disconnected through switching devices, with only two modules working; the same applies to the BS2-V phase and BS3-W phase batteries, reducing unnecessary energy consumption and extending the driving range.

[0116] Charging Operation Mechanism: The electric excavator adopts an on-site charging mode, which can be connected to 380V industrial AC power or a diesel generator for power supply. During charging, the AC charging port is connected to the battery unit through a waterproof plug. The BMS adjusts the charging strategy according to the input power type (AC / generator).

[0117] When connected to mains power, a constant voltage and constant current charging mode is used, with the voltage set at 52V / module and the current at 100A. When connected to a generator (voltage fluctuation ±10%), the BMS stabilizes the input current through high-frequency switching (5kHz) of the switching devices to avoid the impact of voltage fluctuations on the battery cells. During charging, if an imbalance in module voltage is detected (difference > 1V), the BMS activates the active balancing circuit, transferring the power from the high-voltage module to the low-voltage module through the switching devices until the difference is < 0.3V.

[0118] Technical Performance: When applied to electric excavators, this device, through the combination of lithium titanate battery cells and military-grade switching devices, can operate stably in environments ranging from -30℃ to 60℃, with a failure rate of <0.1 times / thousand hours under vibration and shock. The dynamic voltage regulation capability ensures that the voltage fluctuation amplitude is ≤5% under load fluctuations of ±50%, protecting hydraulic system components. The direct AC output characteristic eliminates the need for an inverter, reducing the system response time from the traditional 50ms to 10ms, thus improving operational accuracy.

[0119] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or basic characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of the invention is defined by the appended claims rather than the foregoing description. Therefore, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0120] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A battery device capable of directly outputting AC voltage, characterized in that, include: BS1-U phase battery, BS2-V phase battery and BS3-W phase battery; The negative terminals of the BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery are connected to the neutral point N. The BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery each output one voltage, for a total of three parallel voltage outputs. These three voltages are directly supplied to the motor via three wire harnesses for power supply.

2. The battery device capable of directly outputting AC voltage according to claim 1, characterized in that: The three voltage outputs from the BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery are respectively connected to the U-phase winding, V-phase winding, and W-phase winding of the motor.

3. A battery device capable of directly outputting AC voltage according to claim 1, characterized in that: The BS1-U phase battery, BS2-V phase battery, and BS3-W phase battery each include several groups of cells, which are connected to each other.

4. A battery device capable of directly outputting AC voltage according to claim 3, characterized in that: The BS1-U phase battery comprises several groups of cells, including cell module CU1, cell module CU2, cell module CU3, and cell module CU4, and the four groups of cells are connected by switching devices.

5. A battery device capable of directly outputting AC voltage according to claim 4, characterized in that: The switching devices include SU1, SU2, SU3, SU4, SU5, SU6, SU7, SU8, SU9, SU10, SU11, SU12, SU13, SU14, SU15, SU16, and SU17.

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