Buck-boost charging and discharging circuit and tool for riding instead of walk

Abstract

The invention provides a buck-boost charging and discharging circuit and a tool for riding instead of walk, and relates to the technical field of new energy automobiles. The system comprises a high-voltage battery, an electric driving system and a charging and discharging interface, the high-voltage battery is connected with the electric driving system; the electric driving system is connected with the charging and discharging interface; the electric driving system comprises a plurality of switches, the plurality of switches are alternately closed to control the buck-boost charge-discharge function of the buck-boost charge-discharge circuit, and the plurality of switches are configured in the electric driving system, so that random switching of a power loop from the high-voltage battery to the charge-discharge interface is realized, the normal driving function of the electric driving system can be realized, and the reliability of the electric driving system is improved. And the function of bidirectional boost-buck of the high-voltage battery to the charge-discharge interface can be realized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of new energy vehicles, and in particular to a buck-boost charging and discharging circuit and a means of transportation. Background Art

[0002] With the continuous development of new energy vehicle technology, the problem of long charging time has gradually become prominent and has become an important factor restricting the popularization of new energy vehicles. In order to solve this problem, more and more new energy vehicles have begun to adopt 800V high-voltage platforms to improve charging efficiency. However, most of the charging piles on the market currently only support charging voltages of 500V or 750V, which cannot directly meet the charging needs of new energy vehicles with 800V high-voltage platforms. In addition, the application scenarios of new energy vehicles are relatively limited, mainly concentrated in normal charging, driving, and low-power power supply for household appliances. The battery capacity of new energy vehicles generally reaches more than 100kwh, and has great potential to expand more application scenarios.

[0003] In order to deal with the above problems, the boost charging technology in the current related technologies mostly adopts the method of multiplexing electronically controlled power tubes, motor stator inductors or adding power inductors to form a boost charging circuit. However, the expandable functions of this circuit structure in the related technology are relatively limited, and can only realize the boost charging function of the charging pile for the battery. Summary of the invention

[0004] The present invention provides a step-up / step-down charging and discharging circuit and a means of transportation.

[0005] According to a first aspect of the present disclosure, a buck-boost charging and discharging circuit is provided, the system comprising: a high-voltage battery, an electric drive system and a charging and discharging interface; the high-voltage battery is connected to the electric drive system, and the electric drive system is connected to the charging and discharging interface; the electric drive system comprises a plurality of switches, and the plurality of switches are alternately closed to control the buck-boost charging and discharging function and the normal driving function of the buck-boost charging and discharging circuit.

[0006] In some embodiments, the multiple switches include a first switch, a second switch, a third switch, a fourth switch, a fifth switch and a sixth switch; the multiple switches are configured such that when the buck-boost charge and discharge circuit is in the boost charging function or the buck discharging function, the first switch, the fourth switch, the fifth switch and the sixth switch are closed; when the buck-boost charge and discharge circuit is in the boost discharging function or the buck charging function, the second switch, the third switch, the fifth switch and the sixth switch are closed; when the buck-boost charge and discharge circuit is in the direct charging function or the direct discharging function, the first switch, the second switch, the third switch, the fourth switch and the fifth switch are closed; when the buck-boost charge and discharge circuit is in the normal driving function, the first switch is closed.

[0007] In some embodiments, the electric drive system also includes a three-phase inverter unit, a motor, a first capacitor and a second capacitor; the high-voltage battery is respectively connected to the first end of the first switch and the second end of the first capacitor; the second end of the first switch is respectively connected to the first end of the first capacitor and the first end of the second switch; the three-phase inverter unit is connected to the first end and the second end of the first capacitor; the three-phase inverter unit is connected to the motor; the motor is connected to the first end of the sixth switch; the second end of the sixth switch is connected to the first end of the second capacitor; the second end of the second capacitor is respectively connected to the three-phase inverter unit and the first end of the fifth switch; the first end of the second capacitor is respectively connected to the second end of the third switch and the first end of the fourth switch; the first end of the third switch is connected to the first end of the first switch; the second end of the second switch is connected to the second end of the fourth switch; the second end of the fourth switch and the second end of the fifth switch are both connected to the charge and discharge interface.

[0008] In some embodiments, the three-phase inverter unit includes: a first switch tube bridge arm, a second switch tube bridge arm and a third switch tube bridge arm; the first switch tube bridge arm is formed by connecting the first power switch tube and the second power switch tube in sequence; the second switch tube bridge arm is formed by connecting the third power switch tube and the fourth power switch tube in sequence; the third switch tube bridge arm is formed by connecting the fifth power switch tube and the sixth power switch tube in sequence.

[0009] In some embodiments, the motor includes: a first inductor, a second inductor and a third inductor; the midpoint of the bridge arm of the first switch tube is connected to the first inductor to form a first phase drive circuit; the midpoint of the bridge arm of the second switch tube is connected to the second inductor to form a second phase drive circuit; the midpoint of the bridge arm of the third switch tube is connected to the third inductor to form a third phase drive circuit.

[0010] In some embodiments, the first end of the first capacitor is connected to the first power switch tube, and the second end of the first capacitor is connected to the second power switch tube; the first end of the sixth switch is connected to the center point of the motor or the first phase drive circuit or the second phase drive circuit or the third phase drive circuit; the second end of the second capacitor is connected to the sixth switch tube.

[0011] In some embodiments, the high-voltage battery includes: a power supply, a seventh switch, an eighth switch, a ninth switch and a first resistor; the power supply is connected to the first end of the seventh switch and the first end of the ninth switch, respectively; the second end of the seventh switch is connected to the first end of the first resistor; the first end of the eighth switch is connected to the first end of the seventh switch, and the second end of the eighth switch is connected to the second end of the first resistor; the second end of the first resistor is connected to the first end of the first switch and the first end of the third switch; the second end of the ninth switch is connected to the second end of the first capacitor.

[0012] In some embodiments, the electric drive system also includes: a first power supply filter and a second capacitor filter; the second end of the first switch and the second end of the ninth switch are connected to the first end and the second end of the first capacitor through the first power supply filter; the first end and the second end of the second capacitor are connected to the first end of the fourth switch and the first end of the fifth switch through the second power supply filter.

[0013] In some embodiments, the electric drive system further includes: a fourth inductor, and the first end of the sixth switch is connected to the center point of the motor or the first phase drive circuit or the second phase drive circuit or the third phase drive circuit through the fourth inductor.

[0014] According to a second aspect of the present disclosure, a means of transportation is provided, comprising the buck-boost charging and discharging circuit as described in the first aspect.

[0015] According to an embodiment of the present disclosure, a buck-boost charging and discharging circuit includes: a high-voltage battery, an electric drive system and a charging and discharging interface; the high-voltage battery is connected to the electric drive system, and the electric drive system is connected to the charging and discharging interface; the electric drive system includes a plurality of switches, and the plurality of switches are alternately closed to control the buck-boost charging and discharging function of the buck-boost charging and discharging circuit. By configuring a plurality of switches in the electric drive system, arbitrary switching of the power circuit from the high-voltage battery to the charging and discharging interface can be achieved, which can not only realize the normal driving function of the electric drive system, but also realize the bidirectional buck-boost function of the high-voltage battery to the charging and discharging interface.

[0016] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure. Figure 1 A schematic diagram of a boost circuit structure in a related technology provided by an embodiment of the present disclosure; Figure 2 A schematic diagram of a buck-boost charging and discharging circuit provided in an embodiment of the present disclosure; Figure 3 A schematic diagram of a specific buck-boost charging and discharging circuit provided in an embodiment of the present disclosure; Figure 4 A specific buck-boost charging and discharging circuit with an external power inductor provided in an embodiment of the present disclosure; Figure 5 A schematic diagram of a boost circuit showing the current flow under a boost function provided by an embodiment of the present disclosure; Figure 6 A schematic diagram of a boost circuit showing the current flow under another boost function provided by an embodiment of the present disclosure; Figure 7 A schematic diagram of a buck circuit showing the current flow under a buck function provided by an embodiment of the present disclosure; Figure 8 A schematic diagram of a buck circuit showing the current flow under another buck function provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0018] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0019] A buck-boost charging and discharging system and a means of transportation according to an embodiment of the present disclosure will be described below with reference to the accompanying drawings.

[0020] With the continuous development of new energy vehicle technology, the problem of long charging time has gradually become prominent and has become an important factor restricting the popularization of new energy vehicles. In order to solve this problem, more and more new energy vehicles have begun to adopt 800V high-voltage platforms to improve charging efficiency. However, most of the charging piles on the market currently only support charging voltages of 500V or 750V, which cannot meet the charging needs of new energy vehicles with 800V high-voltage platforms. At present, the application scenarios of new energy vehicles are only normal charging, driving, and low-power power supply for household appliances. In fact, the battery capacity of new energy vehicles has reached more than 100kwh. If there is a high-power bidirectional buck-boost channel between the battery and the outside world, it can expand a lot of other application scenarios, such as: having an input channel for battery buck-boost: it can be compatible with most charging piles on the market and solve the problem of charging incompatibility of the high-voltage 800V platform. Having a buck-boost channel for the battery to the outside world: it can provide temporary power for external high-power equipment to meet the use of special scenarios; it can also realize the function of mobile charging piles to rescue and replenish power for other vehicles.

[0021] like Figure 1 As shown, the present disclosure provides a schematic diagram of a boost circuit structure in a related art. Figure 1 The motor stator inductance and the external power inductor L1 can form a boost inductor. The power tubes T2, T4, and T6 form a boost control tube. The power tubes T1, T3, and T5 are boost rectifier tubes. By controlling the duty cycle of T2, T4, and T6, the voltage of the charging pile is increased to charge the battery. Capacitors C1 and C2 are bus filter capacitors.

[0022] It can be seen that the boost charging technology in the current related technologies mostly adopts the method of reusing electronically controlled power tubes, motor stator windings or adding power inductors and other devices to form a boost charging circuit. Although there are few new devices, the expandable functions are also relatively limited, and basically only the boost charging function of the charging pile to the battery can be realized.

[0023] In order to solve the problems in the related art, the present disclosure proposes a buck-boost charging and discharging circuit. The solution aims to realize the arbitrary switching of the power circuit from the high-voltage battery to the charging and discharging interface by reusing the three-phase inverter unit and the motor in the electric drive system and adding multiple switches to the buck-boost charging and discharging circuit, specifically six switches S1, S2, S3, S4, S5, and S6, which can not only realize the normal driving function of the electric drive system, but also realize the bidirectional buck-boost function of the high-voltage battery to the charging and discharging interface.

[0024] Figure 2 Schematic diagram of a buck-boost charging and discharging circuit provided in an embodiment of the present disclosure. Figure 2 As shown, the buck-boost charging and discharging circuit includes: High-voltage battery 1, electric drive system 2 and charging and discharging interface 3; The high-voltage battery 1 is connected to the electric drive system 2, and the electric drive system 2 is connected to the charge and discharge interface 3; The electric drive system 2 includes a plurality of switches 21, and the plurality of switches 21 are alternately closed to control the buck-boost charging and discharging function and the normal driving function of the buck-boost charging and discharging circuit.

[0025] The high-voltage battery 1 is used as an energy source to provide power for the entire buck-boost charging and discharging circuit. The electric drive system 2 is responsible for controlling the buck-boost and charging and discharging process of the circuit, and the charging and discharging interface 3 is used to connect with external devices to achieve energy input and output.

[0026] The electric drive system 2 is the core part of the buck-boost charging and discharging circuit. It controls the buck-boost charging and discharging function and the normal driving function of the circuit by alternately closing multiple switches. The configuration of these switches determines the behavior of the circuit in different working modes.

[0027] like Figure 3 As shown, it is a schematic diagram of a specific buck-boost charging and discharging circuit provided by the present disclosure.

[0028] Reference Figure 3 In the present disclosure, the specific number of the plurality of switches may be six. The plurality of switches includes a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a fifth switch S5, and a sixth switch S6.

[0029] The configuration principles of multiple switches in this disclosure are specifically as follows: When the buck-boost charging and discharging circuit is in the boost charging function or the buck discharging function, the first switch S1, the fourth switch S4, the fifth switch S5 and the sixth switch S6 are closed, so that the circuit can convert the input low-voltage direct current into high-voltage direct current for charging, or convert the high-voltage direct current into low-voltage direct current for discharging.

[0030] When the buck-boost charging and discharging circuit is in the boost discharge function or the buck charging function, the second switch S2, the third switch S3, the fifth switch S5 and the sixth switch S6 are closed, so that the circuit can convert high-voltage direct current into higher-voltage direct current for discharge, or convert low-voltage direct current into lower-voltage direct current for charging.

[0031] When the buck-boost charging and discharging circuit is in direct charging function or direct discharging function, the first switch S1, the second switch S2, the third switch S3, the fourth switch S4 and the fifth switch S5 of the multiple switches are all closed, so that the circuit can directly transfer the input electric energy to the battery for charging, or directly output the electric energy of the battery to an external device; When the buck-boost charging and discharging circuit is in normal driving function, only the first switch S1 is closed, so that the circuit can maintain a stable output voltage and current to drive the external device to work normally.

[0032] It can be seen that the buck-boost charging and discharging circuit of the present disclosure can switch between multiple working modes through the above-mentioned different switch configurations, thereby meeting different application requirements. The present disclosure can control the flow direction and size of electric energy in the circuit through the alternating closing and opening of the switch, thereby realizing the control of voltage rise and fall and charging and discharging process.

[0033] In some embodiments, the electric drive system 2 further includes a three-phase inverter unit, a motor, a first capacitor C1 and a second capacitor C2.

[0034] The three-phase inverter unit in the present disclosure is used to convert direct current into three-phase alternating current, or in some cases, to convert three-phase alternating current into direct current, and includes a plurality of power switch tubes, and every two of the plurality of power switch tubes form a switch tube bridge arm. In the three-phase inverter unit, the plurality of power switch tubes can form three switch tube bridge arms.

[0035] The motor disclosed herein may be a three-phase motor connected to a three-phase inverter circuit and driven by receiving three-phase alternating current.

[0036] The first capacitor C1 can also be called a DC bus capacitor or a filter capacitor. It plays the role of stabilizing the DC bus voltage, filtering and energy buffering in the buck-boost charging and discharging circuit. During the charging process, the current flows into the circuit through the charging and discharging port. After filtering and stabilization by the first capacitor C1, it can smooth the current flowing in from the charging pile to prevent excessive impact on the power supply or battery, and charge the battery or other energy storage device. During the discharge process, the current flows out of the battery or other energy storage device, and after being buffered by the first capacitor C1 and providing instantaneous energy, it is supplied to the motor or other equipment to meet the rapid start-up or high power requirements of the motor or other equipment.

[0037] The second capacitor C2 also plays a role in filtering and stabilizing the voltage in the buck-boost charging and discharging circuit. Especially during the charging and discharging process, it helps to reduce current fluctuations and voltage ripples, making the charging and discharging process more stable and reliable. This connection method ensures that the second capacitor C2 can effectively filter out high-frequency noise and fluctuations in the current flowing in or out of the charging and discharging port.

[0038] Among them, the connection relationship of each device in the electric drive system in the present disclosure is specifically as follows: the high-voltage battery 1 is respectively connected to the first end of the first switch S1 and the second end of the first capacitor C1; the second end of the first switch S1 is respectively connected to the first end of the first capacitor C1 and the first end of the second switch S2; the three-phase inverter unit is connected to the first end and the second end of the first capacitor CA; the three-phase inverter unit is connected to the motor; the motor is connected to the first end of the sixth switch S6; the second end of the sixth switch S6 is connected to the first end of the second capacitor C2; the second end of the second capacitor C2 is respectively connected to the three-phase inverter unit and the first end of the fifth switch S5; the first end of the second capacitor C2 is respectively connected to the second end of the third switch S3 and the first end of the fourth switch S4; the first end of the third switch S3 is connected to the first end of the first switch S1; the second end of the second switch S2 is connected to the second end of the fourth switch S4; the second end of the fourth switch S4 and the second end of the fifth switch S5 are both connected to the charge and discharge interface 3.

[0039] The three-phase inverter unit in the present disclosure is composed of six power switch tubes (such as IGBT, MOSFET, etc.), namely, the first power switch tube T1, the second power switch tube T2, the third power switch tube T3, the fourth power switch tube T4, the fifth power switch tube T5, and the sixth power switch tube T6. Through these six power switch tubes, three switch tube bridge arms can be formed, and each bridge arm includes two power switch tubes. By controlling the on and off states of the power switch tubes, three-phase alternating current can be generated to drive the motor.

[0040] In some embodiments, the three-phase inverter unit includes: a first switch tube bridge arm, a second switch tube bridge arm and a third switch tube bridge arm; the first switch tube bridge arm is formed by connecting the first power switch tube T1 and the second power switch tube T2 in sequence; the second switch tube bridge arm is formed by connecting the third power switch tube T3 and the fourth power switch tube T4 in sequence; the third switch tube bridge arm is formed by connecting the fifth power switch tube T5 and the sixth power switch tube T6 in sequence.

[0041] In some embodiments, the motor may include multiple inductors; the midpoint of the bridge arm of each switch tube bridge arm in the three-phase inverter unit (i.e., the connection point between each two power switch tubes in the vertical direction) is respectively connected to the multiple inductors of the motor to form a three-phase drive circuit.

[0042] Specifically, the motor includes three inductors. The three inductors represent the three main windings of the motor, namely the first inductor, the second inductor, and the third inductor, which correspond to the three phases of the motor (U phase, V phase, and W phase). These inductors are arranged in a specific way inside the motor to generate a rotating magnetic field, thereby driving the motor to rotate.

[0043] In the present disclosure, the circuit system composed of the three-phase inverter unit and the three inductors of the motor is called a three-phase drive circuit. Specifically, the midpoint of the bridge arm of the first switch tube bridge arm is connected to the first inductor (i.e., the U-phase inductor) to form a first-phase drive circuit; the midpoint of the bridge arm of the second switch tube bridge arm is connected to the second inductor (i.e., the V-phase inductor) to form a second-phase drive circuit; the midpoint of the bridge arm of the third switch tube bridge arm is connected to the third inductor (i.e., the W-phase inductor) to form a third-phase drive circuit.

[0044] This circuit system is responsible for converting direct current into three-phase alternating current suitable for motor drive, and accurately controls the motor's speed, direction and torque by controlling the size, frequency and phase of the current.

[0045] Among them, the connection method of the first capacitor and the second capacitor to the power switch tube in the three-phase inverter unit is specifically as follows: the first end of the first capacitor C1 is connected to the first power switch tube T1, and the second end of the first capacitor C1 is connected to the second power switch tube T2; the first end of the sixth switch S6 is connected to the center point of the motor or the first phase drive circuit or the second phase drive circuit or the third phase drive circuit; the second end of the second capacitor C2 is connected to the sixth switch tube.

[0046] In some embodiments, the high-voltage battery specifically includes: a power supply, a seventh switch S7, an eighth switch S8, a ninth switch S9 and a first resistor R1; the power supply is respectively connected to the first end of the seventh switch S7 and the first end of the ninth switch S9; the second end of the seventh switch S7 is connected to the first end of the first resistor R1; the first end of the eighth switch S8 is connected to the first end of the seventh switch S7, and the second end of the eighth switch S8 is connected to the second end of the first resistor R1; the second end of the first resistor R1 is connected to the first end of the first switch and the first end of the third switch S3; the second end of the ninth switch S9 is connected to the second end of the first capacitor C1.

[0047] In the present disclosure, in order to realize the boost charging function or the buck discharging function, the boost discharging function or the buck charging function, the direct charging function or the direct discharging function, and the normal driving function, the present disclosure configures the eighth switch S8 and the ninth switch S9 in the high-voltage battery to be closed.

[0048] In some embodiments, in order to smooth the current and reduce voltage fluctuations to ensure current stability, the electric drive system of the present invention may also include: a first power supply filter and a second capacitor filter; the second end of the first switch and the second end of the ninth switch are connected to the first end and the second end of the first capacitor through the first power supply filter; the first end and the second end of the second capacitor are connected to the first end of the fourth switch and the first end of the fifth switch through the second power supply filter.

[0049] In some embodiments, the present disclosure may also add an external power inductor, such as Figure 4 As shown, the present disclosure provides a specific buck-boost charging and discharging circuit with an added external power inductor. That is, the electric drive system further includes: a fourth inductor L1, and a first end of a sixth switch S6 is connected to a center point of the motor or a first phase drive circuit or a second phase drive circuit or a third phase drive circuit through the fourth inductor L1.

[0050] Based on the above-mentioned buck-boost charging and discharging circuit, the present disclosure can realize the buck-boost charging and discharging function, and the specific principle is as follows: For the boost function, the three inductors in the motor disclosed in the present invention constitute the boost inductor, the power switch tubes T2, T4, and T6 constitute the boost control tube, and the power switch tubes T1, T3, and T5 are boost rectifier tubes. Figure 5 , Figure 6 The boost circuit schematic diagram shows the current flow under the boost function.

[0051] Reference Figure 5 and Figure 6 The boost function disclosed in the present invention can first control the opening of T2, T4, and T6 to supplement the energy of the motor stator inductance, and then control the cutoff of T2, T4, and T6. T1, T3, and T5 can realize the boost function through active or passive rectification, and the energy flows from the B terminal to the A terminal.

[0052] The present disclosure increases the voltage at the B terminal to supply power to the A terminal by controlling the duty cycle of T2, T4, and T6, and can control the voltage and current at the A terminal. The first capacitor C1 and the second capacitor C2 are bus filter capacitors.

[0053] For the step-down function, the three inductors in the motor of the present disclosure constitute the step-down filter inductor, the power switch tubes T1, T3, and T5 constitute the step-down control tube, and the power switch tubes T2, T4, and T6 are the inductor freewheeling tubes. Figure 7 , Figure 8 The schematic diagram of the buck circuit showing the current flow under the buck function is shown in FIG. Figure 7 and Figure 8 The buck function of the present invention can first control the opening of T1, T3, and T5 to transmit energy to the motor stator inductance, the first capacitor C2, and the load at the B end, and then control the cutoff of T1, T3, and T5. The power tubes T2, T4, and T6 can realize the buck function through active or passive rectification, and the energy is transmitted to the B end and the A end.

[0054] By controlling the duty cycle of T1, T3, and T5, the voltage reduction discharge from end A to end B can be achieved, and the voltage and current of end B can be controlled. Capacitors C1 and C2 are bus filter capacitors.

[0055] The present disclosure can realize boost charging and boost discharging functions based on the above-mentioned boost function by controlling different switch combinations. Similarly, the present disclosure can also realize buck charging and buck discharging functions based on the above-mentioned buck function by controlling different switch combinations.

[0056] In summary, through the buck-boost charging and discharging circuit disclosed in the present invention, six switches are configured in the electric drive system. By configuring the closed state of the six switches, the power circuit from the high-voltage battery to the charging and discharging interface can be switched at will, which not only realizes the normal driving function of the electric drive system, but also realizes the bidirectional buck-boost function of the high-voltage battery to the charging and discharging interface.

[0057] According to an embodiment of the present disclosure, the present disclosure provides a means of transportation, the aforementioned charging and discharging method can be applied to the means of transportation, and the aforementioned buck-boost charging and discharging circuit can be configured in the means of transportation.

[0058] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely disclosed examples consistent with some aspects of the present disclosure as detailed in the appended claims.

[0059] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0060] Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A buck-boost charging and discharging circuit, characterized in that: The circuit comprises: High-voltage battery, electric drive system, and charging and discharging interface; The high-voltage battery is connected to the electric drive system, and the electric drive system is connected to the charge and discharge interface; The electric drive system includes a plurality of switches, and the plurality of switches are alternately closed to control the buck-boost charging and discharging function and the normal driving function of the buck-boost charging and discharging circuit.

2. The circuit according to claim 1, characterized in that The plurality of switches include a first switch, a second switch, a third switch, a fourth switch, a fifth switch and a sixth switch; The plurality of switches are configured such that when the buck-boost charging and discharging circuit is in a boost charging function or a buck discharging function, the first switch, the fourth switch, the fifth switch and the sixth switch are closed; When the buck-boost charging and discharging circuit is in a boost discharge function or a buck charging function, the second switch, the third switch, the fifth switch and the sixth switch are closed; When the buck-boost charging and discharging circuit is in direct charging function or direct discharging function, the first switch, the second switch, the third switch, the fourth switch and the fifth switch are closed; When the buck-boost charging and discharging circuit is in normal driving function, the first switch is closed.

3. The circuit according to claim 2, characterized in that The electric drive system further includes a three-phase inverter unit, a motor, a first capacitor and a second capacitor; The high-voltage battery is respectively connected to the first end of the first switch and the second end of the first capacitor; The second end of the first switch is connected to the first end of the first capacitor and the first end of the second switch respectively; The three-phase inverter unit is connected to the first end and the second end of the first capacitor; The three-phase inverter unit is connected to the motor; The motor is connected to the first end of the sixth switch; The second end of the sixth switch is connected to the first end of the second capacitor; The second end of the second capacitor is connected to the first end of the three-phase inverter unit and the fifth switch respectively; The first end of the second capacitor is connected to the second end of the third switch and the first end of the fourth switch respectively; The first end of the third switch is connected to the first end of the first switch; The second end of the second switch is connected to the second end of the fourth switch; The second end of the fourth switch and the second end of the fifth switch are both connected to the charge and discharge interface.

4. The circuit according to claim 3, characterized in that The three-phase inverter unit comprises: a first switch tube bridge arm, a second switch tube bridge arm and a third switch tube bridge arm; The first switch tube bridge arm is formed by sequentially connecting a first power switch tube and a second power switch tube; The second switch tube bridge arm is formed by sequentially connecting the third power switch tube and the fourth power switch tube; The third switch tube bridge arm is formed by sequentially connecting the fifth power switch tube and the sixth power switch tube.

5. The circuit according to claim 4, characterized in that The motor comprises: a first inductor, a second inductor and a third inductor; The midpoint of the bridge arm of the first switch tube bridge arm is connected to the first inductor to form a first phase drive circuit; The midpoint of the bridge arm of the second switch tube bridge arm is connected to the second inductor to form a second phase drive circuit; The bridge arm midpoint of the third switch tube bridge arm is connected to the third inductor to form a third phase drive circuit.

6. The circuit according to claim 5, characterized in that A first end of the first capacitor is connected to the first power switch tube, and a second end of the first capacitor is connected to the second power switch tube; A first end of the sixth switch is connected to the center point of the motor or the first phase drive circuit or the second phase drive circuit or the third phase drive circuit; The second end of the second capacitor is connected to the sixth switch tube.

7. The circuit according to claim 3, characterized in that The high-voltage battery includes: a power supply, a seventh switch, an eighth switch, a ninth switch and a first resistor; The power source is connected to the first end of the seventh switch and the first end of the ninth switch respectively; The second end of the seventh switch is connected to the first end of the first resistor; A first end of the eighth switch is connected to a first end of the seventh switch, and a second end of the eighth switch is connected to a second end of the first resistor; The second end of the first resistor is connected to the first end of the first switch and the first end of the third switch; The second end of the ninth switch is connected to the second end of the first capacitor.

8. The circuit according to claim 7, characterized in that The electric drive system further comprises: a first power supply filter and a second power supply filter; The second end of the first switch and the second end of the ninth switch are connected to the first end and the second end of the first capacitor through the first power supply filter; The first end and the second end of the second capacitor are connected to the first end of the fourth switch and the first end of the fifth switch through the second power supply filter.

9. The circuit according to claim 6, characterized in that The electric drive system also includes: a fourth inductor, and the first end of the sixth switch is connected to the center point of the motor or the first phase drive circuit or the second phase drive circuit or the third phase drive circuit through the fourth inductor.

10. A means of transport, characterized in that: It comprises the buck-boost charging and discharging circuit as claimed in any one of claims 1 to 9.

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