Vehicle-mounted battery charging circuit and method

Abstract

The present invention discloses a vehicle-mounted battery charging circuit and method, belonging to the field of charging control technology. The vehicle-mounted battery charging circuit of the present invention comprises: a three-phase bridge arm circuit, an electric control switch circuit, a motor and a control unit, the midpoint of each phase bridge arm in the three-phase bridge arm circuit is connected to the coil of the corresponding motor, the first end of the electric control switch circuit is connected to the positive pole of the external charging device, the second end of the electric control switch circuit is connected to the midpoint of the corresponding bridge arm in the three-phase bridge arm circuit, the control unit controls the on and off of the electric control switch circuit according to the rotor angle of the motor, and the control unit controls the on and off of the three-phase bridge arm circuit according to the on and off of the electric control switch circuit. The present invention controls the corresponding on of the appropriate electric control switch circuit and the three-phase bridge arm circuit according to the rotor angle of the motor, reduces the cost of the boosting equipment and the jitter at the beginning and end of charging, uses the motor coil to realize the boosting function, reduces the cost of the boosting equipment, and improves the user's experience when charging.

Description

Technical Field

[0001] The present invention relates to the technical field of charging control, and in particular to a vehicle-mounted battery charging circuit and method. Background Art

[0002] At present, the voltage levels of existing charging piles on the market are basically at two platforms: 500V and 700V. In order to meet the needs of fast charging, the battery voltage of the whole vehicle needs to be increased to above 800V. Therefore, some charging piles cannot meet the charging voltage level requirements of the whole vehicle, and additional high-voltage direct current conversion (DC / DC) functional equipment is required, which increases the vehicle charging cost and reduces the user experience.

[0003] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0004] The main purpose of the present invention is to provide a vehicle-mounted battery charging circuit and method, aiming to solve the technical problem that the existing charging scheme requires additional high-voltage DC conversion function equipment, which increases the vehicle charging cost.

[0005] To achieve the above object, the present invention provides a vehicle-mounted battery charging circuit, the vehicle-mounted battery charging circuit comprising: a three-phase bridge arm circuit, an electric control switch circuit, a motor and a control unit, wherein:

[0006] The positive pole of the three-phase bridge arm circuit is connected to the positive pole of the vehicle battery, the negative pole of the three-phase bridge arm circuit is connected to the negative pole of the vehicle battery and the negative pole of the external charging device, and the midpoint of each phase arm in the three-phase bridge arm circuit is connected to the corresponding coil of the motor;

[0007] The first end of the electronically controlled switch circuit is connected to the positive electrode of the external charging device, and the second end of the electronically controlled switch circuit is connected to the midpoint of the corresponding bridge arm in the three-phase bridge arm circuit;

[0008] When receiving a charging instruction, the control unit controls the on and off of the electric control switch circuit according to the rotor angle of the motor;

[0009] The control unit controls the on and off of the three-phase bridge arm circuit according to the on and off of the electronically controlled switch circuit.

[0010] Optionally, the electronically controlled switch circuit includes a plurality of control switches, and the control unit selects on and off of any one of the control switches according to the rotor angle of the motor.

[0011] Optionally, the three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel, and the electronically controlled switch circuit includes a first control switch and a second control switch, wherein the first end of the first control switch is connected to the positive pole of the external charging device, and the second end of the first control switch is connected to the midpoint of the first phase bridge arm; the first end of the second control switch is connected to the positive pole of the external charging device, and the second end of the second control switch is connected to the midpoint of the second phase bridge arm.

[0012] Optionally, the electronically controlled switch circuit further includes a third control switch, wherein a first end of the third control switch is connected to the positive electrode of the external charging device, and a second end of the third control switch is connected to the midpoint of the third phase bridge arm.

[0013] Optionally, the first control switch, the second control switch and the third control switch are relays.

[0014] In addition, the present invention also provides a vehicle-mounted battery charging method, which is applied to the vehicle-mounted battery charging circuit as described above, and the vehicle-mounted battery charging circuit includes: a three-phase bridge arm circuit, an electric control switch circuit, a motor and a control unit;

[0015] The method for charging a vehicle battery comprises:

[0016] When receiving a charging instruction, the control unit controls the on and off of the electric control switch circuit according to the current rotor angle of the motor;

[0017] The control unit controls the conduction of the corresponding bridge arm in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit;

[0018] The coil of the motor boosts the voltage input by the external charging device;

[0019] The control unit changes the conduction position of the three-phase bridge arm circuit, and the coil of the motor transmits the boosted voltage to the vehicle battery through the three-phase bridge arm circuit.

[0020] Optionally, the control unit stores a first phase, a second phase, and a third phase for determining a rotor angle position interval, and when receiving a charging instruction, the control unit controls the on and off of the electronically controlled switch circuit according to the rotor angle of the current motor, including:

[0021] When receiving a charging instruction, the control unit aligns the zero position of the rotor with the first phase, the second phase, or the third phase;

[0022] It is determined whether the rotor angle of the current motor falls within a position interval between the first phase, the second phase and the third phase, and the on and off of the electronically controlled switch circuit is controlled according to the position interval.

[0023] Optionally, the control unit controls the conduction of corresponding bridge arms in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit, including:

[0024] The control unit controls the lower bridge of one phase of the three-phase bridge arm circuit to be turned on and the upper bridge to be turned off according to the conduction position of the electronically controlled switch circuit during the voltage boost process;

[0025] The control unit changes the conduction position of the three-phase bridge arm circuit, including:

[0026] During the charging process, the control unit controls the lower bridge of the one-phase bridge arm circuit to be turned off and the upper bridge to be turned on.

[0027] Optionally, the three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel to each other, and the electronically controlled switch circuit includes a first control switch and a second control switch, wherein a first end of the first control switch is connected to a positive electrode of an external charging device, and a second end of the first control switch is connected to a midpoint of the first phase bridge arm; a first end of the second control switch is connected to a positive electrode of the external charging device, and a second end of the second control switch is connected to a midpoint of the second phase bridge arm;

[0028] When receiving the charging instruction, the control unit controls the on and off of the electric control switch circuit according to the current rotor angle of the motor, including:

[0029] When receiving the charging instruction, the control unit controls the first control switch to be turned on and the second control switch to be turned off according to the current rotor angle of the motor;

[0030] The control unit controls the conduction of the corresponding bridge arm in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit, including:

[0031] The control unit controls the lower bridge of the second phase bridge arm to be turned on and the upper bridge of the second phase bridge arm to be turned off according to the conduction position of the electronically controlled switch circuit;

[0032] The control unit changes the conduction position of the three-phase bridge arm circuit, including:

[0033] The control unit controls the lower bridge of the second phase bridge arm to be turned off and the upper bridge of the second phase bridge arm to be turned on.

[0034] Optionally, the three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel, and the electronically controlled switch circuit includes a first control switch and a second control switch, wherein the first end of the first control switch is connected to the positive electrode of the external charging device, and the second end of the first control switch is connected to the midpoint of the first phase bridge arm; the first end of the second control switch is connected to the positive electrode of the external charging device, and the second end of the second control switch is connected to the midpoint of the second phase bridge arm;

[0035] When receiving the charging instruction, the control unit controls the on and off of the electric control switch circuit according to the current rotor angle of the motor, including:

[0036] When receiving the charging instruction, the control unit controls the conduction of the second control switch and controls the turn-off of the first control switch according to the current rotor angle of the motor;

[0037] The control unit controls the conduction of the corresponding bridge arm in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit, including:

[0038] The control unit controls the lower bridge of the first phase bridge arm to be turned on and the upper bridge of the first phase bridge arm to be turned off according to the conduction position of the electronically controlled switch circuit;

[0039] The control unit changes the conduction position of the three-phase bridge arm circuit, including:

[0040] The control unit controls the lower bridge of the first phase bridge arm to be turned off and the upper bridge of the first phase bridge arm to be turned on.

[0041] Optionally, the three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel to each other, and the electronically controlled switch circuit includes a first control switch, a second control switch and a third control switch, wherein a first end of the first control switch is connected to a positive electrode of an external charging device, and a second end of the first control switch is connected to a midpoint of the first phase bridge arm; a first end of the second control switch is connected to a positive electrode of the external charging device, and a second end of the second control switch is connected to a midpoint of the second phase bridge arm; a first end of the third control switch is connected to a positive electrode of the external charging device, and a second end of the third control switch is connected to a midpoint of the third phase bridge arm;

[0042] When receiving the charging instruction, the control unit controls the on and off of the electric control switch circuit according to the current rotor angle of the motor, including:

[0043] When receiving the charging instruction, the control unit controls the conduction of the third control switch according to the current rotor angle of the motor, and controls the first control switch and the second control switch to be turned off;

[0044] The control unit controls the conduction of the corresponding bridge arm in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit, including:

[0045] The control unit controls the lower bridge of the first phase bridge arm to be turned on and the upper bridge of the first phase bridge arm to be turned off according to the conduction position of the electronically controlled switch circuit;

[0046] The control unit changes the conduction position of the three-phase bridge arm circuit, including:

[0047] The control unit controls the lower bridge of the first phase bridge arm to be turned off and the upper bridge of the first phase bridge arm to be turned on.

[0048] The vehicle battery charging circuit of the present invention comprises: a three-phase bridge arm circuit, an electric control switch circuit, a motor and a control unit. The positive pole of the three-phase bridge arm circuit is connected to the positive pole of the vehicle battery, the negative pole of the three-phase bridge arm circuit is connected to the negative pole of the vehicle battery and the negative pole of the external charging device, the midpoint of each phase bridge arm in the three-phase bridge arm circuit is connected to the coil of the corresponding motor, the first end of the electric control switch circuit is connected to the positive pole of the external charging device, and the second end of the electric control switch circuit is connected to the midpoint of the corresponding bridge arm in the three-phase bridge arm circuit. When receiving a charging instruction, the control unit controls the on and off of the electric control switch circuit according to the rotor angle of the motor. The control unit controls the on and off of the three-phase bridge arm circuit according to the on and off of the electric control switch circuit. The present invention reduces the cost of boosting equipment and the jitter at the start and end of charging by controlling the corresponding on of the appropriate electric control switch circuit and the three-phase bridge arm circuit according to the rotor angle of the motor, and uses the motor coil to realize the boosting function, reduces the cost of boosting equipment, and improves the user experience when charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a structural schematic diagram of a first embodiment of a vehicle-mounted battery charging circuit of the present invention;

[0050] Figure 2 A schematic diagram of the motor rotor angle of an embodiment of a vehicle-mounted battery charging circuit of the present invention;

[0051] Figure 3 This is a flow chart of a first embodiment of a vehicle battery charging method according to the present invention;

[0052] Figure 4 A schematic diagram of the three-phase voltage vector relationship of the vehicle-mounted battery charging method of the present invention;

[0053] Figure 5 A schematic diagram of the vector relationship of the first angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0054] Figure 6A schematic diagram of the current path of the first angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0055] Figure 7 A schematic diagram of the vector relationship of the second angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0056] Figure 8 A schematic diagram of the current path of the second angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0057] Fig. 9 A schematic diagram of the vector relationship of the third angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0058] Fig.10 A schematic diagram of the current path in the third angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0059] Fig.11 A schematic diagram of the vector relationship of the fourth angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0060] Fig.12 A schematic diagram of a current path in a fourth angle sub-interval of a vehicle-mounted battery charging method according to the present invention;

[0061] Fig.13 A schematic diagram of the vector relationship of the fifth angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0062] Fig.14 A schematic diagram of the current path of the fifth angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0063] Fig.15 A schematic diagram of the vector relationship of the sixth angle sub-interval of the vehicle-mounted battery charging method of the present invention;

[0064] Fig.16 Schematic diagram of the current path in the sixth angle sub-interval of the vehicle battery charging method of the present invention.

[0065] Description of Figure Numbers:

[0066] Label name Label name 10 Three-phase bridge arm circuit U First phase bridge arm 20 Electronically controlled switch circuit V Second phase bridge arm 30 Motor W The third phase bridge arm 40 Car battery VT1~VT6 The first to sixth switching tubes 50 External charging device VD1~VD6 The first to sixth diodes C1 capacitance R1~R5 First to fifth control switches + positive electrode - negative electrode

[0067] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0068] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0069] Reference Figure 1 , Figure 1 It is a structural schematic diagram of the first embodiment of the vehicle-mounted battery charging circuit of the present invention.

[0070] The vehicle-mounted battery charging circuit comprises: a three-phase bridge arm circuit 10, an electric control switch circuit 20, a motor 30 and a control unit, wherein:

[0071] The positive pole + of the three-phase bridge arm circuit 10 is connected to the positive pole + of the vehicle battery 40, the negative pole - of the three-phase bridge arm circuit 10 is connected to the negative pole - of the vehicle battery 40 and the negative pole - of the external charging device 50, and the midpoint of each phase arm of the three-phase bridge arm circuit 10 is connected to the corresponding coil of the motor 30;

[0072] The first end of the electric control switch circuit 20 is connected to the positive electrode + of the external charging device 50, and the second end of the electric control switch circuit 20 is connected to the midpoint of the corresponding bridge arm in the three-phase bridge arm circuit 10;

[0073] When receiving the charging instruction, the control unit controls the on and off of the electronically controlled switch circuit 20 according to the rotor angle of the motor 30 .

[0074] It is understandable that the electronically controlled switch circuit 20 receives the charging instruction, indicating that it has detected that charging can begin. The electronically controlled switch circuit 20 can obtain the rotor angle of the motor 30, such as Figure 2 , where S represents the south pole of the magnet, N represents the north pole of the magnet, and the coordinate axis is established with the zero point direction of the motor 30 as the horizontal coordinate. The angle α between the horizontal coordinate direction and the direction of the south pole of the magnet represents the rotor angle of the motor 30. The rotor angle of the motor 30 can be detected by using a resolver sensor.

[0075] It is easy to understand that by determining the position interval where the rotor angle is located, the on and off of a control switch in the electronically controlled switch circuit 20 can be determined according to the position interval, thereby further satisfying the charging start condition.

[0076] The control unit controls the on / off of the three-phase bridge arm circuit 10 according to the on / off of the electronically controlled switch circuit 20 .

[0077] It is easy to understand that the control unit controls the on and off of a control switch in the electronically controlled switch circuit 20 corresponding to the rotor angle according to the rotor angle, and further controls the on and off of the switch (switch tube) of one-phase bridge arm circuit in the three-phase bridge arm circuit 10 according to the on and off of a control switch in the electronically controlled switch circuit 20. The switch (switch tube) of one-phase bridge arm circuit can be fully turned on or partially turned on, or fully turned off or partially turned off.

[0078] It is understandable that when the control switch of the electronically controlled switch circuit 20 and the switch (switch tube) of the one-phase bridge arm circuit corresponding to the rotor angle are closed, the motor 30 can convert the low-voltage charging voltage input by the external charging device 50 into a high-voltage charging voltage through the motor 30 coil (inductor). Among them, the use of the motor 30 inductor and the switching element to achieve the boost function can reduce the cost of additional boost equipment, so that it can be suitable for charging at different voltages, and can reduce the temperature rise and torque of the motor 30 during charging. At the same time, selecting a suitable two-phase inductor for charging according to the actual position of the rotor of the motor 30 can greatly reduce the jitter at the beginning and end of charging, and improve the user's charging experience.

[0079] It should be noted that during the charging process of the whole vehicle, if only one-phase inductance of the motor 30 is used for charging, the charging efficiency is not high and the motor 30 generates serious heat, which increases the heat dissipation burden of the whole machine. Long-term use under high temperature conditions will reduce the life and reliability of the device. If only two-phase inductance of the motor 30 is used for charging without corresponding switch elements, if the position where the motor 30 stops differs too much from the position of the magnetic flux formed by the two-phase inductance, there will be a large jitter at the beginning or end of charging, which reduces the user's experience.

[0080] It is easy to understand that the motor 30 outputs the high-voltage charging voltage to the three-phase bridge arm circuit 10, and after the switch (switch tube) of one phase of the three-phase bridge arm circuit 10 is turned on, the high-voltage charging voltage is output to the vehicle battery 40.

[0081] The vehicle battery charging circuit described in this embodiment includes: a three-phase bridge arm circuit, an electronically controlled switch circuit, a motor and a control unit. The positive electrode of the three-phase bridge arm circuit is connected to the positive electrode of the vehicle battery, the negative electrode of the three-phase bridge arm circuit is connected to the negative electrode of the vehicle battery and the negative electrode of the external charging device, the midpoint of each phase bridge arm in the three-phase bridge arm circuit is connected to the coil of the corresponding motor, the first end of the electronically controlled switch circuit is connected to the positive electrode of the external charging device, and the second end of the electronically controlled switch circuit is connected to the midpoint of the corresponding bridge arm in the three-phase bridge arm circuit. When the control unit receives a charging instruction, it controls the on and off of the electronically controlled switch circuit according to the rotor angle of the motor. The control unit controls the on and off of the three-phase bridge arm circuit according to the on and off of the electronically controlled switch circuit. This embodiment reduces the cost of the boosting equipment and the jitter at the start and end of charging by controlling the appropriate electronically controlled switch circuit and the three-phase bridge arm circuit to be turned on according to the rotor angle position of the motor, and uses the motor coil to realize the boosting function, reduces the cost of the boosting equipment, and improves the user experience when charging.

[0082] Furthermore, the electronically controlled switch circuit 20 includes a plurality of control switches, and the control unit selects the on and off of any of the control switches according to the rotor angle of the motor 30 .

[0083] It is easy to understand that the control unit can determine a corresponding control switch in the electronically controlled switch circuit 20 according to the position interval by judging the position interval of the rotor angle, and control the on and off of the corresponding control switch.

[0084] The three-phase bridge arm circuit 10 includes a first phase bridge arm U, a second phase bridge arm V and a third phase bridge arm W connected in parallel, and the electronically controlled switch circuit 20 includes a first control switch R1 and a second control switch R2, wherein the first end of the first control switch R1 is connected to the positive pole + of the external charging device 50, and the second end of the first control switch R1 is connected to the midpoint of the first phase bridge arm U; the first end of the second control switch R2 is connected to the positive pole + of the external charging device 50, and the second end of the second control switch R2 is connected to the midpoint of the second phase bridge arm V.

[0085] In a specific implementation, the first phase bridge arm U includes: a first switch tube VT1, a second switch tube VT2, a first diode VD1 and a second diode VD2; the emitter of the first switch tube VT1 is respectively connected to the anode of the first diode VD1 and the first end of the motor 30, and the collector of the first switch tube VT1 is connected to the cathode of the first diode VD1; the collector of the second switch tube VT2 is respectively connected to the cathode of the second diode VD2 and the first end of the motor 30, and the emitter of the second switch tube VT2 is connected to the anode of the second diode VD2.

[0086] The second phase bridge arm V includes: a third switch tube VT3, a fourth switch tube VT4, a third diode VD3 and a fourth diode VD4; the emitter of the third switch tube VT3 is respectively connected to the anode of the third diode VD3 and the second end of the motor 30, and the collector of the third switch tube VT3 is connected to the cathode of the third diode VD3; the collector of the fourth switch tube VT4 is respectively connected to the cathode of the fourth diode VD4 and the second end of the motor 30, and the emitter of the fourth switch tube VT4 is connected to the anode of the fourth diode VD4.

[0087] The third phase bridge arm W includes: a fifth switch tube VT5, a sixth switch tube VT6, a fifth diode and a sixth diode VD6; the emitter of the fifth switch tube VT5 is respectively connected to the anode of the fifth diode and the third end of the motor 30, and the collector of the fifth switch tube VT5 is connected to the cathode of the fifth diode; the collector of the sixth switch tube VT6 is respectively connected to the cathode of the sixth diode VD6 and the third end of the motor 30, and the emitter of the sixth switch tube VT6 is connected to the anode of the sixth diode VD6.

[0088] It is easy to understand that the first switch tube VT1, the second switch tube VT2, the third switch tube VT3, the fourth switch tube VT4, the fifth switch tube VT5 and the sixth switch tube VT6 can be specifically insulated gate bipolar transistors (IGBT tubes), and the first diode VD1, the second diode VD2, the third diode VD3, the fourth diode VD4, the fifth diode and the sixth diode VD6 can be specifically freewheeling diodes. Each phase switch subcircuit can include two switch tubes and two diodes, and the switch function is realized by controlling the conduction or disconnection of the switch tube. The control unit conducts by selecting a suitable charging line to improve the charging efficiency.

[0089] The vehicle battery charging circuit further includes a capacitor C1 ; a first end of the capacitor C1 is connected to the positive electrode + of the vehicle battery 40 , and a second end of the capacitor C1 is connected to the negative electrode − of the vehicle battery 40 .

[0090] It can be understood that the capacitor C1 is a filter capacitor C1 of the vehicle-mounted battery charging circuit, which is used to filter the high-voltage charging voltage to filter out clutter in the voltage signal.

[0091] The electronically controlled switch circuit 20 further includes a third control switch R3 , wherein a first end of the third control switch R3 is connected to the positive electrode + of the external charging device 50 , and a second end of the third control switch R3 is connected to the midpoint of the third phase bridge arm W.

[0092] The first control switch R1 , the second control switch R2 , and the third control switch R3 are relays.

[0093] It is easy to understand that the electronically controlled switch circuit 20 includes a first control switch R1, a second control switch R2 and a third control switch R3. The first control switch R1, the second control switch R2 and the third control switch R3 can be devices with switching functions such as relays. The control unit selects one of the first control switch R1, the second control switch R2 and the third control switch R3 to turn on or off according to the rotor angle of the motor 30.

[0094] The electronically controlled switch circuit 20 of this embodiment includes a first control switch R1, a second control switch R2 and a third control switch R3. The three-phase bridge arm circuit 10 includes a first phase bridge arm U, a second phase bridge arm V and a third phase bridge arm W connected in parallel. Each phase bridge arm includes two switch tubes and two diodes to realize the switching function. The first control switch R1, the second control switch R2 and the third control switch R3 are all relays. Through the coordinated action of each switch element, a suitable line is selected to be turned on to realize the switching function and reduce the cost of the boosting equipment.

[0095] The embodiment of the present invention provides a vehicle battery charging method, referring to Figure 3 , Figure 3 This is a flow chart of a first embodiment of a vehicle battery charging method according to the present invention.

[0096] The vehicle-mounted battery charging method is applied to the vehicle-mounted battery charging circuit as described above.

[0097] In this embodiment, the vehicle-mounted battery charging method includes the following steps:

[0098] Step S10: When receiving the charging instruction, the control unit controls the on and off of the electronically controlled switch circuit according to the current rotor angle of the motor.

[0099] It is understandable that the electronically controlled switch circuit receives the charging instruction, indicating that it has detected that charging can start. The electronically controlled switch circuit can obtain the rotor angle of the motor, and by determining the position interval where the rotor angle is located, the on and off of a control switch in the electronically controlled switch circuit can be determined according to the position interval, thereby further satisfying the charging start condition.

[0100] Step S20: the control unit controls the conduction of corresponding bridge arms in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit.

[0101] It is easy to understand that the control unit controls the on and off of a control switch in the electric control switch circuit corresponding to the rotor angle according to the rotor angle, and further controls the on and off of the switch of one-phase bridge arm circuit in the three-phase bridge arm circuit according to the on and off of a control switch in the electric control switch circuit. The switch of one-phase bridge arm circuit can be fully turned on or partially turned on, or fully turned off or partially turned off.

[0102] Step S30: The coil of the motor boosts the voltage input by the external charging device.

[0103] It is understandable that when the switch of the electronically controlled switching circuit and the switch (switch tube) of the one-phase bridge arm circuit corresponding to the rotor angle are closed, the motor can convert the low-voltage charging voltage input by the external charging device into a high-voltage charging voltage through the motor coil (inductor). Among them, the use of motor inductance and switching elements to achieve the boost function can reduce the cost of additional boost equipment, so that it can be suitable for charging at different voltages, and can reduce the temperature rise and torque of the motor during charging. At the same time, selecting a suitable two-phase inductor for charging according to the actual position of the motor can greatly reduce the jitter at the beginning and end of charging, and improve the user's charging experience.

[0104] It should be noted that during the charging process of the whole vehicle, if only one phase of the motor inductance is used for charging, the charging efficiency is low and the motor heats up seriously, which increases the heat dissipation burden of the whole machine. Long-term use under high temperature conditions will reduce the life and reliability of the device. If only the two-phase inductance of the motor is used for charging without corresponding switch elements, if the position where the motor stops differs too much from the position of the magnetic flux formed by the two-phase inductance, there will be a large jitter at the beginning or end of charging, which will reduce the user experience.

[0105] Step S40: the control unit changes the conduction position of the three-phase bridge arm circuit, and the coil of the motor transmits the boosted voltage to the vehicle battery through the three-phase bridge arm circuit.

[0106] It is easy to understand that the control unit changes the on-off state of the switch (switch tube) of one phase of the three-phase bridge arm circuit, and the motor outputs the high-voltage charging voltage to the three-phase bridge arm circuit. After the switch (switch tube) of one phase of the three-phase bridge arm circuit is turned on, the high-voltage charging voltage is output to the vehicle battery.

[0107] The vehicle battery charging circuit described in this embodiment includes: a three-phase bridge arm circuit, an electronically controlled switch circuit, a motor and a control unit. The positive electrode of the three-phase bridge arm circuit is connected to the positive electrode of the vehicle battery, the negative electrode of the three-phase bridge arm circuit is connected to the negative electrode of the vehicle battery and the negative electrode of the external charging device, the midpoint of each phase bridge arm in the three-phase bridge arm circuit is connected to the coil of the corresponding motor, the first end of the electronically controlled switch circuit is connected to the positive electrode of the external charging device, and the second end of the electronically controlled switch circuit is connected to the midpoint of the corresponding bridge arm in the three-phase bridge arm circuit. When receiving a charging instruction, the control unit controls the on and off of the electronically controlled switch circuit according to the rotor angle of the motor. The control unit controls the on and off of the three-phase bridge arm circuit according to the on and off of the electronically controlled switch circuit. This embodiment reduces the cost of the boosting equipment and the jitter at the start and end of charging by controlling the appropriate electronically controlled switch circuit and the three-phase bridge arm circuit to be turned on according to the rotor angle of the motor, and uses the motor coil to realize the boosting function, reduces the cost of the boosting equipment, and improves the user experience when charging.

[0108] Based on the above embodiment, in the vehicle battery charging method of this embodiment, the control unit stores the first phase, the second phase and the third phase for determining the rotor angle position interval, and the step S10 includes:

[0109] When receiving a charging instruction, the control unit aligns the zero position of the rotor with the first phase, the second phase, or the third phase;

[0110] It is determined whether the rotor angle of the current motor falls within a position interval between the first phase, the second phase and the third phase, and the on and off of the electronically controlled switch circuit is controlled according to the position interval.

[0111] It is easy to understand that Figure 4 , the spatial angles between the first phase, the second phase and the third phase are all 120°, the position interval between the first phase and the second phase can be set to the first angle interval (0°≤α﹤120°), the position interval between the second phase and the third phase can be set to the second angle interval (120°≤α﹤240°), and the position interval between the third phase and the first phase can be set to the third angle interval (240°≤α﹤360°), wherein the first angle interval can be further divided into a first angle sub-interval (0°≤α﹤60°) and a second angle sub-interval (60°≤α﹤120°), the second angle interval can be further divided into a third angle sub-interval (120°≤α﹤180°) and a fourth angle sub-interval (180°≤α﹤240°), and the third angle interval can be further divided into a fifth angle sub-interval (180°≤α﹤300°) and a sixth angle sub-interval (300°≤α﹤360°). The control unit can control the on and off of a switch in the electric control switch circuit corresponding to the interval according to the angle sub-interval in which the current rotor angle is located.

[0112] The step S20 comprises:

[0113] During the voltage boosting process, the control unit controls the lower bridge of one phase bridge arm circuit of the three-phase bridge arm circuit to be turned on and the upper bridge to be turned off according to the conduction position of the electronically controlled switch circuit.

[0114] During the charging process, the control unit controls the lower bridge of the one-phase bridge arm circuit to be turned off and the upper bridge to be turned on.

[0115] It is easy to understand that the control unit controls the on and off of the switch (switch tube) of one phase bridge arm circuit in the three-phase bridge arm circuit according to the on and off of a control switch in the electronically controlled switch circuit. During the boosting process, the lower bridge of one phase bridge arm circuit of the three-phase bridge arm circuit can be controlled to be turned on and the upper bridge to be turned off. The boosting process is that the coil of the motor 30 boosts the voltage input by the external charging device 50. During the charging process, the lower bridge of the one-phase bridge arm circuit is controlled to be turned off and the upper bridge is turned on. The charging process is that the coil of the motor 30 outputs the boosted voltage to the three-phase bridge arm circuit.

[0116] In a specific implementation, the three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel, and the electronically controlled switch circuit includes a first control switch R1, a second control switch R2 and a third control switch R3, wherein the first end of the first control switch R1 is connected to the positive pole of the external charging device 50, and the second end of the first control switch R1 is connected to the midpoint of the first phase bridge arm; the first end of the second control switch R2 is connected to the positive pole of the external charging device 50, and the second end of the second control switch R2 is connected to the midpoint of the second phase bridge arm; the first end of the third control switch R3 is connected to the positive pole of the external charging device 50, and the second end of the third control switch R3 is connected to the midpoint of the third phase bridge arm.

[0117] When receiving the charging instruction, the control unit controls the conduction of the third control switch R3 according to the current rotor angle of the motor 30, and controls the first control switch R1 and the second control switch R2 to be turned off;

[0118] The control unit controls the lower bridge of the first phase bridge arm to be turned on and the upper bridge of the first phase bridge arm to be turned off according to the conduction position of the electronically controlled switch circuit;

[0119] The control unit controls the lower bridge of the first phase bridge arm to be turned off and the upper bridge of the first phase bridge arm to be turned on.

[0120] It is easy to understand that Figure 5 , if the rotor angle is 30°, satisfying 0°≤α﹤60° (the first angle sub-interval), at this time, the switch (VT1) of the upper bridge arm of the first phase bridge arm circuit is controlled to be closed, so that the current enters the coil (W phase) connected to the third phase bridge arm circuit and exits the upper bridge arm (U phase) of the first phase bridge arm circuit, such as Figure 6 At this time, the current path flows through the third control switch R3, the coil of the motor 30, VT1, the fourth control switch R4, the vehicle battery 40, the fifth control switch R5 in sequence, and finally returns to the external charging device 50.

[0121] It is easy to understand that Figure 7 , if the rotor angle is 90°, satisfying 60°≤α﹤120° (the second angle sub-interval), at this time, the switch (VT3) of the upper arm of the second-phase bridge arm circuit is controlled to be closed, so that the current enters from the coil (W phase) connected to the third-phase bridge arm circuit and exits from the upper arm (V phase) of the second-phase bridge arm circuit, such as Figure 8 At this time, the current path flows through the third control switch R3, the coil of the motor 30, VT3, the fourth control switch R4, the vehicle battery 40, the fifth control switch R5 in sequence, and finally returns to the external charging device 50.

[0122] In a specific implementation, the three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel, and the electronically controlled switch circuit includes a first control switch R1 and a second control switch R2, wherein the first end of the first control switch R1 is connected to the positive pole of the external charging device 50, and the second end of the first control switch R1 is connected to the midpoint of the first phase bridge arm; the first end of the second control switch R2 is connected to the positive pole of the external charging device 50, and the second end of the second control switch R2 is connected to the midpoint of the second phase bridge arm.

[0123] When receiving a charging instruction, the control unit controls the conduction of the first control switch R1 and the turn-off of the second control switch R2 according to the current rotor angle of the motor 30; the control unit controls the conduction of the lower bridge of the second phase bridge arm and the turn-off of the upper bridge of the second phase bridge arm according to the conduction position of the electronically controlled switch circuit; the control unit controls the turn-off of the lower bridge of the second phase bridge arm and the conduction of the upper bridge of the second phase bridge arm.

[0124] It is understandable that if Fig. 9 , if the rotor angle is 150°, satisfying 120°≤α﹤180° (third angle sub-interval), at this time, the switch (VT3) of the upper bridge arm of the second-phase bridge arm circuit is controlled to be closed, so that the current enters from the coil (U phase) connected to the first-phase bridge arm and exits from the upper bridge arm (V phase) of the second-phase bridge arm circuit, such as Fig.10 At this time, the current path flows through the first control switch R1, the coil of the motor 30, VT3, the fourth control switch R4, the vehicle battery 40, the fifth control switch R5 in sequence, and finally returns to the external charging device 50.

[0125] It is easy to understand that Fig.11 , if the rotor angle is 210°, it satisfies 180°≤α﹤240° (the fourth angle sub-interval), at this time, the switch (VT5) of the upper arm of the third-phase bridge arm circuit is controlled to be closed, so that the current enters from the coil (U phase) connected to the first-phase bridge arm and exits from the upper arm (W phase) of the third-phase bridge arm circuit, such as Fig.12 At this time, the current path flows through the first control switch R1, the coil of the motor 30, VT5, the fourth control switch R4, the vehicle battery 40, the fifth control switch R5 in sequence, and finally returns to the external charging device 50.

[0126] In a specific implementation, the three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel, and the electronically controlled switch circuit includes a first control switch R1 and a second control switch R2, wherein the first end of the first control switch R1 is connected to the positive pole of the external charging device 50, and the second end of the first control switch R1 is connected to the midpoint of the first phase bridge arm; the first end of the second control switch R2 is connected to the positive pole of the external charging device 50, and the second end of the second control switch R2 is connected to the midpoint of the second phase bridge arm.

[0127] When receiving a charging instruction, the control unit controls the conduction of the second control switch R2 according to the current rotor angle of the motor 30, and controls the turn-off of the first control switch R1; the control unit controls the conduction of the lower bridge of the first phase bridge arm and the turn-off of the upper bridge of the first phase bridge arm according to the conduction position of the electronically controlled switch circuit; the control unit controls the turn-off of the lower bridge of the first phase bridge arm and the conduction of the upper bridge of the first phase bridge arm.

[0128] It is easy to understand that Fig.13 , if the rotor angle is 270°, satisfying 240°≤α﹤300° (fifth angle sub-interval), at this time, the switch (VT5) of the upper arm of the third-phase bridge arm circuit is controlled to be closed, so that the current enters from the coil (V phase) connected to the second-phase bridge arm circuit and exits from the upper arm (W phase) of the third-phase bridge arm circuit, such as Fig.14 At this time, the current path flows through the second control switch R2, the coil of the motor 30, VT5, the fourth control switch R4, the vehicle battery 40, the fifth control switch R5 in sequence, and finally returns to the external charging device 50.

[0129] It is easy to understand that Fig.15 , if the rotor angle is 330°, satisfying 300°≤α﹤360° (the sixth angle sub-interval), at this time, the switch (VT1) of the upper bridge arm of the first-phase bridge arm circuit is controlled to be closed, so that the current enters from the coil (V phase) connected to the second-phase bridge arm circuit and exits from the upper bridge arm (U phase) of the first-phase bridge arm circuit, such as Fig.16 At this time, the current path flows through the second control switch R2, the coil of the motor 30, VT5, the fourth control switch R4, the vehicle battery 40, the fifth control switch R5 in sequence, and finally returns to the external charging device 50.

[0130] This embodiment synthesizes a vector position based on the position of the rotor and the phase of the current entering and flowing out. When the position of the rotor is closest to the synthesized vector position, the corresponding control switch and bridge arm circuit are controlled to be turned on and off, so that the current enters and flows out at the desired phase, so that the rotation position of the rotor is minimized during the charging process of the vehicle, thereby reducing the jitter of the entire vehicle during charging.

[0131] It should be understood that the above is only an example and does not constitute any limitation on the technical solution of the present invention. In specific applications, technicians in this field can make settings as needed, and the present invention does not limit this.

[0132] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of the present invention. In practical applications, technicians in this field can select part or all of them according to actual needs to achieve the purpose of the present embodiment, and no limitation is made here.

[0133] In addition, for technical details not fully described in this embodiment, reference can be made to the vehicle-mounted battery charging circuit and method provided in any embodiment of the present invention, and will not be repeated here.

[0134] In addition, it should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0135] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0136] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A vehicle-mounted battery charging circuit, characterized in that: The vehicle-mounted battery charging circuit includes: a three-phase bridge arm circuit, an electric control switch circuit, a motor and a control unit, wherein: The positive pole of the three-phase bridge arm circuit is connected to the positive pole of the vehicle battery, the negative pole of the three-phase bridge arm circuit is connected to the negative pole of the vehicle battery and the negative pole of the external charging device, and the midpoint of each phase arm in the three-phase bridge arm circuit is connected to the corresponding coil of the motor; The first end of the electronically controlled switch circuit is connected to the positive electrode of the external charging device, and the second end of the electronically controlled switch circuit is connected to the midpoint of the corresponding bridge arm in the three-phase bridge arm circuit; When receiving a charging instruction, the control unit controls the on and off of the electric control switch circuit according to the rotor angle of the motor; The control unit controls the on and off of the three-phase bridge arm circuit according to the on and off of the electronically controlled switch circuit.

2. The vehicle-mounted battery charging circuit according to claim 1, characterized in that: The electronically controlled switch circuit includes a plurality of control switches, and the control unit selects the on and off of any one of the control switches according to the rotor angle of the motor.

3. The vehicle-mounted battery charging circuit as claimed in claim 2, characterized in that: The three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel, and the electronically controlled switch circuit includes a first control switch and a second control switch, wherein the first end of the first control switch is connected to the positive pole of the external charging device, and the second end of the first control switch is connected to the midpoint of the first phase bridge arm; the first end of the second control switch is connected to the positive pole of the external charging device, and the second end of the second control switch is connected to the midpoint of the second phase bridge arm.

4. The vehicle-mounted battery charging circuit as claimed in claim 3, characterized in that: The electronically controlled switch circuit further includes a third control switch, wherein a first end of the third control switch is connected to the positive electrode of the external charging device, and a second end of the third control switch is connected to the midpoint of the third phase bridge arm.

5. The vehicle-mounted battery charging circuit as claimed in claim 4, characterized in that: The first control switch, the second control switch and the third control switch are relays.

6. A method for charging a vehicle battery, characterized in that: The vehicle-mounted battery charging method is applied to the vehicle-mounted battery charging circuit as claimed in any one of claims 1 to 5, wherein the vehicle-mounted battery charging circuit comprises: a three-phase bridge arm circuit, an electric control switch circuit, a motor and a control unit; The method for charging a vehicle battery comprises: When receiving a charging instruction, the control unit controls the on and off of the electric control switch circuit according to the current rotor angle of the motor; The control unit controls the conduction of the corresponding bridge arm in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit; The coil of the motor boosts the voltage input by the external charging device; The control unit changes the conduction position of the three-phase bridge arm circuit, and the coil of the motor transmits the boosted voltage to the vehicle battery through the three-phase bridge arm circuit.

7. The vehicle-mounted battery charging method according to claim 6, characterized in that: The control unit stores a first phase, a second phase, and a third phase for determining a rotor angle position interval. When receiving a charging instruction, the control unit controls the on and off of the electric control switch circuit according to the current rotor angle of the motor, including: When receiving a charging instruction, the control unit aligns the zero position of the rotor with the first phase, the second phase, or the third phase; It is determined whether the rotor angle of the current motor falls within a position interval between the first phase, the second phase and the third phase, and the on and off of the electronically controlled switch circuit is controlled according to the position interval.

8. The vehicle-mounted battery charging method according to claim 7, characterized in that: The control unit controls the conduction of the corresponding bridge arm in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit, including: The control unit controls the lower bridge of one phase of the three-phase bridge arm circuit to be turned on and the upper bridge to be turned off according to the conduction position of the electronically controlled switch circuit during the voltage boost process; The control unit changes the conduction position of the three-phase bridge arm circuit, including: During the charging process, the control unit controls the lower bridge of the one-phase bridge arm circuit to be turned off and the upper bridge to be turned on.

9. The vehicle-mounted battery charging method according to claim 8, characterized in that: The three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel to each other, and the electronically controlled switch circuit includes a first control switch and a second control switch, wherein a first end of the first control switch is connected to a positive electrode of an external charging device, and a second end of the first control switch is connected to a midpoint of the first phase bridge arm; a first end of the second control switch is connected to a positive electrode of the external charging device, and a second end of the second control switch is connected to a midpoint of the second phase bridge arm; When receiving the charging instruction, the control unit controls the on and off of the electric control switch circuit according to the current rotor angle of the motor, including: When receiving the charging instruction, the control unit controls the first control switch to be turned on and the second control switch to be turned off according to the current rotor angle of the motor; The control unit controls the conduction of the corresponding bridge arm in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit, including: The control unit controls the lower bridge of the second phase bridge arm to be turned on and the upper bridge of the second phase bridge arm to be turned off according to the conduction position of the electronically controlled switch circuit; The control unit changes the conduction position of the three-phase bridge arm circuit, including: The control unit controls the lower bridge of the second phase bridge arm to be turned off and the upper bridge of the second phase bridge arm to be turned on.

10. The vehicle-mounted battery charging method according to claim 8, characterized in that: The three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel, and the electronically controlled switch circuit includes a first control switch and a second control switch, wherein the first end of the first control switch is connected to the positive electrode of the external charging device, and the second end of the first control switch is connected to the midpoint of the first phase bridge arm; the first end of the second control switch is connected to the positive electrode of the external charging device, and the second end of the second control switch is connected to the midpoint of the second phase bridge arm; When receiving the charging instruction, the control unit controls the on and off of the electric control switch circuit according to the current rotor angle of the motor, including: When receiving the charging instruction, the control unit controls the conduction of the second control switch and controls the turn-off of the first control switch according to the current rotor angle of the motor; The control unit controls the conduction of the corresponding bridge arm in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit, including: The control unit controls the lower bridge of the first phase bridge arm to be turned on and the upper bridge of the first phase bridge arm to be turned off according to the conduction position of the electronically controlled switch circuit; The control unit changes the conduction position of the three-phase bridge arm circuit, including: The control unit controls the lower bridge of the first phase bridge arm to be turned off and the upper bridge of the first phase bridge arm to be turned on.

11. The vehicle-mounted battery charging method according to claim 8, characterized in that: The three-phase bridge arm circuit includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel, and the electronically controlled switch circuit includes a first control switch, a second control switch and a third control switch, wherein a first end of the first control switch is connected to a positive electrode of an external charging device, and a second end of the first control switch is connected to a midpoint of the first phase bridge arm; a first end of the second control switch is connected to a positive electrode of the external charging device, and a second end of the second control switch is connected to a midpoint of the second phase bridge arm; a first end of the third control switch is connected to a positive electrode of the external charging device, and a second end of the third control switch is connected to a midpoint of the third phase bridge arm; When receiving the charging instruction, the control unit controls the on and off of the electric control switch circuit according to the current rotor angle of the motor, including: When receiving the charging instruction, the control unit controls the conduction of the third control switch according to the current rotor angle of the motor, and controls the first control switch and the second control switch to be turned off; The control unit controls the conduction of the corresponding bridge arm in the three-phase bridge arm circuit according to the conduction position of the electronically controlled switch circuit, including: The control unit controls the lower bridge of the first phase bridge arm to be turned on and the upper bridge of the first phase bridge arm to be turned off according to the conduction position of the electronically controlled switch circuit; The control unit changes the conduction position of the three-phase bridge arm circuit, including: The control unit controls the lower bridge of the first phase bridge arm to be turned off and the upper bridge of the first phase bridge arm to be turned on.

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