An electric vehicle charging and driving integrated controller

Abstract

The application relates to a charging and driving integrated controller of an electric vehicle, which comprises a driving module and a charging module. The driving module is an improved three-phase asymmetric half-bridge circuit, two common-source connected switch tubes are used to replace an A-phase lower tube and a B-phase upper tube, a B-phase motor winding is connected with a manual switch in series, and then connected with the series connection points of switch tubes and diodes in an upper tube bridge arm and a lower tube bridge arm of the B-phase asymmetric half-bridge circuit. The charging module comprises a first capacitor and a rectifier bridge. The two ends of the first capacitor are connected with the series connection points of switch tubes and diodes in a lower tube bridge arm of an A-phase asymmetric half-bridge circuit and the series connection points of switch tubes and diodes in an upper tube bridge arm of a B-phase asymmetric half-bridge circuit respectively. Two output ends of the rectifier bridge are connected with the series connection points of the B-phase motor winding and the manual switch and the positive pole of a storage battery respectively, and the input end of the rectifier bridge is connected with commercial power. The application can realize the functions of motor driving and storage battery charging, does not need to additionally add a charger, can realize step-up and step-down charging, and the externally connected parts are all passive devices, so that the application has excellent stability and reliability.

Description

Technical Field

[0001] This application relates to the field of electric vehicle charging control, specifically to an integrated controller for electric vehicle charging and driving. Background Technology

[0002] Existing electric bicycle charging typically employs a method of reusing a portion of the power circuit to achieve charging functionality. Specifically, this involves using a modified drive circuit to rectify the external mains power and then processing the voltage to charge the battery. Patent CN103414337A discloses a power converter topology for a switched reluctance motor in an electric vehicle, which incorporates a bidirectional Buck-Boost circuit between the battery and the power circuit to reuse the power portion, achieving boost driving and rectified buck charging. Patent CN110120769A discloses a switched reluctance motor control system with power factor correction charging function, which achieves rectified boost charging during charging by reusing the power portion. However, both methods have significant limitations: they can only achieve either boost or buck charging functions, and they cannot operate when the charging input voltage is too high or too low, thus limiting their applicability and flexibility and failing to fully utilize the potential of the drive circuit. Summary of the Invention

[0003] The purpose of this invention is to provide an integrated electric vehicle charging and driving controller that can realize both motor driving and battery charging functions without the need for an additional charger. It can achieve step-up and step-down charging, and all external components are passive devices, exhibiting excellent stability and reliability.

[0004] The technical solution adopted by this invention is: an integrated controller for charging and driving electric vehicles, comprising a drive module and a charging module. The drive module includes an A-phase asymmetrical half-bridge circuit, a B-phase asymmetrical half-bridge circuit, a C-phase asymmetrical half-bridge circuit, a battery, and a manual switch. The A-phase, B-phase, and C-phase asymmetrical half-bridge circuits are all connected in parallel with the battery. Each asymmetrical half-bridge circuit includes an upper bridge arm and a lower bridge arm. The upper bridge arm of the A-phase asymmetrical half-bridge circuit, the lower bridge arm of the B-phase asymmetrical half-bridge circuit, and the upper and lower bridge arms of the C-phase asymmetrical half-bridge circuit are all connected in parallel with the battery. The bridge arm structures are identical, each consisting of a switch and a diode connected in series. The lower bridge arm of the A-phase asymmetrical half-bridge circuit and the upper bridge arm of the B-phase asymmetrical half-bridge circuit have the same structure, both consisting of two switches connected in series with a common source and a diode. The A-phase motor winding and the C-phase motor winding are connected to the series connection point of the switch and diode in the upper and lower bridge arms of the A-phase and C-phase asymmetrical half-bridge circuits, respectively. The B-phase motor winding is connected in series with the manual switch and then to the series connection point of the switch and diode in the upper and lower bridge arms of the B-phase asymmetrical half-bridge circuit.

[0005] The charging module includes a first capacitor and a rectifier bridge. The two ends of the first capacitor C1 are connected to the series connection point of the switch and diode in the lower bridge arm of the A-phase asymmetrical half-bridge circuit and the series connection point of the switch and diode in the upper bridge arm of the B-phase asymmetrical half-bridge circuit, respectively. The two output terminals of the rectifier bridge are connected to the series connection point of the B-phase motor winding and the manual switch and the positive terminal of the battery, respectively. The input terminal of the rectifier bridge is connected to the mains power.

[0006] Furthermore, the electric vehicle charging and driving integrated controller has two working modes: driving mode and charging mode. In driving mode, the three-phase motor is driven, the manual switch is closed, and the charging module is not connected to the driving module. In charging mode, the battery is charged, the manual switch is open, and the charging module is connected to the driving module.

[0007] Furthermore, the upper bridge arm of the B-phase asymmetrical half-bridge circuit includes a third and a third second switch. In drive mode, the third second switch is always on, while the third first switch is turned on and off according to the PWM drive signal. In charging mode, the third first switch is always on, while the third second switch is turned on and off according to the PWM drive signal, with a duty cycle of D. In charging mode control, the charging output voltage Vout and the rectified input voltage Vin satisfy Vout = -Vin × D / (1 - D), where Vin is the rectified input voltage and Vout is the battery charging voltage. The battery can be charged regardless of whether the rectified mains voltage is higher or lower than the battery voltage.

[0008] The beneficial effects of this invention are as follows:

[0009] (1) The present invention adopts a non-boost charging circuit structure, which overcomes the limitation that the input voltage must be lower than the battery voltage in the existing switched reluctance motor charging scheme, realizes that the charging input voltage is not limited by size, significantly expands the input voltage range, and thus greatly expands the applicable scenarios of the drive integrated system.

[0010] (2) The present invention connects the motor winding directly to the battery and utilizes the continuous current characteristics of the winding inductance to overcome the problem of poor controllability of charging current caused by the injection of high-frequency pulse current through diode in the traditional boost drive method. It realizes smooth, continuous and precise control of the battery charging current, and significantly improves the stability and control quality of the charging process. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the circuit structure according to an embodiment of the present invention;

[0013] Figure 2 This is a schematic diagram of the connection relationship between the driving module and the charging module in an embodiment of the present invention; wherein, "×" indicates that the charging module is an external circuit module, and the driving module is only connected in the charging mode, and not connected in the driving mode.

[0014] Figure 3 This is a schematic diagram showing the current flow in the circuit when the third switch Q31 and the third switch Q32 are turned on; where "×" indicates that the switch is turned off and "√" indicates that the switch is turned on.

[0015] Figure 4 This is a schematic diagram of the current flow in the circuit when the third switch Q32 is turned off and the third switch Q31 remains on; where "×" indicates that the switch is turned off and "√" indicates that the switch is on. Detailed Implementation

[0016] To better understand the above-described objects, features, and advantages of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Many specific details are set forth in the following description to provide a thorough understanding of the invention; however, the invention may be practiced in other ways different from those described herein, and therefore, the invention is not limited to the specific embodiments disclosed below.

[0017] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art described herein. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” etc., are used only to indicate relative positional relationships, which change accordingly when the absolute position of the described object changes.

[0018] like Figure 2As shown, an integrated controller for charging and driving an electric vehicle includes a drive module and a charging module. The drive module includes an A-phase asymmetrical half-bridge circuit, a B-phase asymmetrical half-bridge circuit, a C-phase asymmetrical half-bridge circuit, a battery (US), and a manual switch. The A-phase, B-phase, and C-phase asymmetrical half-bridge circuits are all connected in parallel with the battery (US). Each asymmetrical half-bridge circuit includes an upper bridge arm and a lower bridge arm. The upper bridge arm of the A-phase asymmetrical half-bridge circuit and the lower bridge arm of the B-phase asymmetrical half-bridge circuit have the same structure as the upper and lower bridge arms of the C-phase asymmetrical half-bridge circuit, each including a series-connected switch. The A-phase asymmetrical half-bridge circuit has the same structure as the B-phase asymmetrical half-bridge circuit, consisting of two switching transistors connected in series with a diode connected to a common source. The A-phase motor winding and the C-phase motor winding are connected to the series connection point of the switching transistor and diode in the upper and lower arms of the A-phase and C-phase asymmetrical half-bridge circuits, respectively. The B-phase motor winding is connected in series with the manual switch and then to the series connection point of the switching transistor and diode in the upper and lower arms of the B-phase asymmetrical half-bridge circuit.

[0019] In this embodiment of the invention, the lower bridge arm of the A-phase asymmetrical half-bridge circuit includes a second diode D2, a second first switch Q21, and a second second switch Q22. The second first switch Q21 and the second second switch Q22 are connected to a common source, the drain of the second first switch Q21 is connected to the anode of the second diode D2, and the drain of the second second switch Q22 is connected to the anode of the first diode D1. The upper bridge arm of the B-phase asymmetrical half-bridge circuit is composed of a third first switch Q31, a third second switch Q32, and a third diode D3. The third first switch Q31 and the third second switch Q32 are connected to a common source. The double-switch structure formed by the connection and the third diode D3 in series constitute the upper bridge arm of the B-phase asymmetrical half-bridge circuit; the lower bridge arm of the B-phase asymmetrical half-bridge circuit is formed by the fourth switch Q4 and the fourth diode D4 in series, the drain of the third switch Q3 is connected to the cathode of the fourth diode D4, and the source of the fourth switch Q4 is connected to the anode of the third diode D3; the upper bridge arm of the C-phase asymmetrical half-bridge circuit is formed by the fifth switch Q5 and the fifth diode D5 in series, and the lower bridge arm is formed by the sixth switch Q6 and the sixth diode D6 in series, the drain of the fifth switch Q5 is connected to the cathode of the sixth diode D6, and the source of the sixth switch Q6 is connected to the anode of the fifth diode D5.

[0020] In drive mode, when the motor operates in phase A, the first switch Q1, the second switch Q21, and the second switch Q22 are simultaneously turned on to store energy in the phase A winding. When the first switch Q1, the second switch Q21, and the second switch Q22 are simultaneously turned off, the phase A winding releases energy through the freewheeling current of the first diode D1 and the second diode D2. When the motor operates in phase B, the third switch Q32 is always turned on, and the third switch Q31 and the fourth switch Q4 are simultaneously turned on to store energy in the phase B winding. When the third switch Q31 and the fourth switch Q4 are simultaneously turned off, the phase B winding releases energy through the freewheeling current of the third diode D3 and the fourth diode D4. When the motor operates in phase C, the fifth switch Q5 and the sixth switch Q6 are simultaneously turned on to store energy in the phase C winding. When the fifth switch Q5 and the sixth switch Q6 are simultaneously turned off, the inductance of the phase C winding releases energy through the freewheeling current of the fifth diode D5 and the sixth diode D6.

[0021] The charging module includes a first capacitor C1 and a rectifier bridge. The two ends of the first capacitor C1 are connected to the series connection point of the switch and diode in the lower bridge arm of the A-phase asymmetrical half-bridge circuit and the series connection point of the switch and diode in the upper bridge arm of the B-phase asymmetrical half-bridge circuit, respectively. The two output terminals of the rectifier bridge are connected to the series connection point of the B-phase motor winding and the manual switch and the positive terminal of the battery US, respectively. The input terminal of the rectifier bridge is connected to the mains power.

[0022] This invention has two operating modes: a driving mode and a charging mode. Figure 2As shown, the drive mode is used to drive the three-phase motor. In this mode, the manual switch S is closed, and the charging module is not connected to the drive module. In drive mode, when the motor is operating in phase A, the first switch Q1, the second switch Q21, and the second switch Q22 of the asymmetrical half-bridge circuit in phase A are controlled: During phase A conduction, the second switch Q21 and the second switch Q22 remain normally on, and the first switch Q1 is high-frequency modulated. When all three switches are on, the current flow is: battery US positive terminal → first switch Q1 → phase A winding → second switch Q21 → second switch Q22 → battery US negative terminal. During conduction, energy is stored in the phase A winding. When the motor operates away from phase A, the first switch Q1, the second switch Q21, and the second switch Q22 are all turned off. At this time, the energy stored in the phase A winding is released through the freewheeling current of the first diode D1 and the second diode D2. When the motor operates in phase B, phase B is based on a charging multiplexing topology, i.e., the third switch Q32 and the manual switch S. As long as this embodiment of the invention is operating in drive mode, regardless of which phase it is operating in, the third switch Q32 is always turned on, and the manual switch S is always closed. The third switch Q31 acts as the original upper switch of phase B, and the fourth switch Q4 acts as the lower switch of phase B. During the conduction of phase B... The fourth switch Q4 remains constantly on, while the third switch Q31 is high-frequency modulated. When both the third switch Q31 and the fourth switch Q4 are on, the current flow is: battery US positive terminal → third switch Q31 → third switch Q32 → B-phase winding → fourth switch Q4 → battery US negative terminal. During the on-state, the B-phase winding stores energy. When the motor operates away from the B-phase, both the third switch Q31 and the fourth switch Q4 in the B-phase are off. At this time, the energy stored in the B-phase winding is released through the freewheeling current of the third diode D3 and the fourth diode D4. When the motor operates in the C-phase, the C-phase asymmetrical half-bridge circuit... The fifth switch Q5 and the sixth switch Q6 are used for control. During the conduction of phase C, the sixth switch Q6 remains constantly on, while the fifth switch Q5 is high-frequency modulated. When both the fifth switch Q5 and the sixth switch Q6 are on, the current flow is: battery US positive terminal → fifth switch Q5 → phase C winding → sixth switch Q6 → battery US negative terminal. During the conduction period, the phase C winding stores energy. When the motor operates away from phase C, both the fifth switch Q5 and the sixth switch Q6 are off. At this time, the energy stored in the phase C winding is released through the fifth diode D5 and the sixth diode D6, and the three-phase cyclic conduction maintains the normal operation of the motor. In this embodiment of the invention, the third second switch Q32 remains on in the drive mode, and the third first switch Q31 and... Figure 1 The third switch, Q31, performs the same function and participates in the control drive.

[0023] The charging mode is used to charge the battery. In this mode, the manual switch S is open, the charging module is connected to the drive module, and the mains power, after rectification by the rectifier bridge, is connected to one end of the B-phase winding of the motor (positive terminal) and the negative terminal to the positive terminal of the battery, providing DC input power to the entire charging circuit. During charging, the third switch Q31 is always on. The duty cycle of the third switch Q32 is controlled by the PWM drive signal. At this time, the voltage relationship exists: Vout = -Vin × D / (1-D), where Vin is the rectified mains input voltage, Vout is the charging voltage, and D is the duty cycle of the third switch Q32. Based on the charging voltage required by the battery US, regardless of whether the rectified mains input voltage Vin is greater or less than the required charging voltage, the duty cycle D of the third switch Q32 can be adjusted to make the charging voltage Vout reach the required charging voltage of the battery US. When the rectified input voltage Vin is less than the charging voltage Vout, the duty cycle D of the third switch Q32 is adjusted to be greater than 0.5, thereby achieving boost charging; when the rectified input voltage Vin is greater than the charging voltage Vout, the duty cycle D of the third switch Q32 is adjusted to be less than 0.5, thereby achieving buck charging. During charging, the first switch Q1, the second switch Q21, the second switch Q22, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6 are all off. In this embodiment of the invention, the rectifier bridge is a single-phase uncontrolled rectifier circuit composed of four diodes.

[0024] like Figure 3 As shown, when the third switch Q31 and the third switch Q32 are turned on, the rectified mains power energy forms an excitation circuit through the motor B-phase winding, the third switch Q31, and the third switch Q32, storing energy in the motor B-phase winding; at the same time, the first capacitor C1 releases energy to the battery US through the A-phase winding, and the current passes through the third switch Q31, the third switch Q32, and the battery US, forming a charging circuit through the first diode D1.

[0025] like Figure 4 As shown, when the third switch Q32 is turned off and the third switch Q31 remains on, the mains rectified voltage charges the first capacitor C1. The energy stored in the A-phase winding of the three-phase motor freewheels through the second diode D2 and the first diode D1, maintaining the stability of the output load current, thereby achieving a stable charging process for the electric vehicle battery.

[0026] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An integrated controller for charging and driving electric vehicles, characterized in that, The system includes a drive module and a charging module. The drive module comprises an A-phase asymmetrical half-bridge circuit, a B-phase asymmetrical half-bridge circuit, a C-phase asymmetrical half-bridge circuit, a battery, and a manual switch. The A-phase, B-phase, and C-phase asymmetrical half-bridge circuits are all connected in parallel with the battery. Each asymmetrical half-bridge circuit includes an upper bridge arm and a lower bridge arm. The upper bridge arm of the A-phase asymmetrical half-bridge circuit, the lower bridge arm of the B-phase asymmetrical half-bridge circuit, and the upper and lower bridge arms of the C-phase asymmetrical half-bridge circuit have the same structure, all including series connections. The circuit consists of a switching transistor and a diode. The lower bridge arm of the A-phase asymmetrical half-bridge circuit and the upper bridge arm of the B-phase asymmetrical half-bridge circuit have the same structure, both consisting of two switching transistors and a diode connected in series with a common source. The A-phase motor winding and the C-phase motor winding are respectively connected to the series connection point of the switching transistor and diode in the upper and lower bridge arms of the A-phase and C-phase asymmetrical half-bridge circuits. The B-phase motor winding is connected in series with the manual switch and then to the series connection point of the switching transistor and diode in the upper and lower bridge arms of the B-phase asymmetrical half-bridge circuit. The charging module includes a first capacitor and a rectifier bridge. The two ends of the first capacitor are respectively connected to the series connection point of the switching transistor and diode in the lower bridge arm of the A-phase asymmetrical half-bridge circuit and the series connection point of the switching transistor and diode in the upper bridge arm of the B-phase asymmetrical half-bridge circuit. The positive output terminal of the rectifier bridge is connected to the series connection point of the B-phase motor winding and the manual switch, the negative output terminal of the rectifier bridge is connected to the positive terminal of the battery, and the input terminal of the rectifier bridge is connected to the mains power. The electric vehicle charging and driving integrated controller has two working modes: driving mode and charging mode. In driving mode, the three-phase motor is driven and the manual switch is closed, and the charging module is not connected to the driving module. In charging mode, the battery is charged and the manual switch is open, and the charging module is connected to the driving module. The upper bridge arm of the B-phase asymmetrical half-bridge circuit includes a third-first switch and a third-second switch. In drive mode, the third-second switch is always on, while the third-first switch is turned on and off according to the PWM drive signal. In charging mode, the third-first switch is always on, while the third-second switch is turned on and off according to the PWM drive signal, with a duty cycle of D. In charging mode control, the charging output voltage Vout and the rectified input voltage Vin of the rectifier bridge satisfy Vout = -Vin × D / (1 - D), where Vin is the rectified input voltage of the rectifier bridge, and Vout is the charging voltage of the battery. The battery can be charged regardless of whether the rectified mains voltage is higher or lower than the battery voltage.

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