[0039] The present invention will be described in detail below with reference to the accompanying drawings.
[0040] Such as Figures 1 to 7 As shown, the power battery heating method in this embodiment, the motor system employed includes the motor controller 41 and the three-phase motor 42, the three-phase motor 42 is a three-phase three-wire electric machine, and the motor controller 41 includes a control module. , Three-phase bridge arm and bus capacitance C, three-phase bridge arms are connected in parallel by U-phase bridge arm, V-phase bridge arm and W-phase bridge arm, bus capacitance C and U-phase bridge arm, V-phase bridge arm, W photo bridge arm in parallel. The U-phase bridge arm is connected by the upper bridge arm power switch S1 and the lower bridge arm power switch S4, and the V-phase bridge arm is connected by the upper bridge arm power switch S2 and the lower bridge arm power switch S5, and the W phase bridge arm is from the upper bridge arm. Power switch S3 and the lower bridge arm power switch S6 connection configuration. In this implementation, the upper bridge arm power switch S1, the upper bridge arm power switch S2, the upper bridge power switch S3, the lower bridge arm power switch S4, the lower bridge arm power switch S5 and the lower bridge arm power switch S6 are IGBT modules, The bridge arm power switch S1, the upper bridge arm power switch S2, the upper bridge power switch S3, the lower bridge arm power switch S4, the lower bridge arm power switch S5, and the lower bridge arm power switch S6 have a continuous flow diode. The midpoint of the U-phase bridge arm (ie the connection point of the upper bridge arm power switch S1 and the lower bridge power switch S4) leads connects the u-phase fixing sub-winding L1 of the three-phase motor 42 (ie the upper bridge) The connection point of the arm power switch S2 and the lower bridge arm power switch S5 is connected to the midpoint of the V-phase fixing sub-winding L2 of the three-phase motor 42 (ie, the upper bridge power switch S3 and the lower bridge power switch S6) The connection point) lead is connected to the W-phase fixing sub-winding L3 of the three-phase motor 42. The motor rotor position signal output of the three-phase motor 42 (which integrates the rotor position sensor) is connected to the signal acquisition end of the control module. The upper bridge arm power switch S1, the upper bridge arm power switch S2, the upper bridge arm power switch S3 upper end lead connection power battery 1 of the positive, lower bridge arm power switch S4, the lower bridge arm power switch S5, the lower bridge arm power switch S6 The lower end lead is connected to the negative electrode of the power battery 1 to form a power battery pulse heating circuit. The control terminal of the upper bridge arm power switch S1, the control terminal of the upper bridge arm power switch S2, the control terminal of the upper bridge arm power switch S3, the control terminal of the lower bridge arm power switch S4, the control terminal of the lower bridge arm power switch S5 and The control terminals of the lower bridge arm power switch S6 are connected to the six control outputs of the control module, respectively.
[0041] The power battery heating method is: When the pulse heating enters conditions, that is, the pulse heating opening request is received, and the vehicle is in a high pressure parking state, and there is no pulse heating fault, the motor system enters the pulse heating mode, and the power battery is performed. Pulse heating, the cooling liquid of the absorbing motor system heats the power battery heat in the cooling line of the power battery 1; when the pulse heating exit condition is satisfied, the pulse heating shutdown request is received, or the vehicle is driving, or when pulse is heated The motor system exits the pulse heating mode, stops the power battery pulse heating, the cooling liquid in the cooling line of the power battery stops heating the power battery due to stopping flowing.
[0042] Among them, in pulse heating mode, the control module performs the following steps:
[0043] According to the pulse current size request value IREQ query current-voltage meter, the current axis voltage request value UD is obtained; where the current-voltage meter is the corresponding relationship between the measured pulse current size request value and the direct axis voltage request value by calibration mode. table.
[0044] According to the motor rotor position signal, PARK inverse transformation is performed on the current axis voltage request value UD and the preset shaft voltage Uq to obtain the α-axis voltage vector u. α And β-axis voltage vectors U β This preset shaft voltage UQ = 0.
[0045] A pulse signal having a cycle 1 / f is generated according to the pulse current frequency request value f; wherein the previous 1 / 2F time in one cycle is high (ie 1), and the time 1 / 2F is low. (Ie 0).
[0046] According to the alpha axis voltage vector u α , Β-axis voltage vector u β And the pulse current frequency request value f, generate six power switches (ie the upper bridge power switch S1, the upper bridge power switch S2, the upper bridge power switch S3, the lower bridge arm power switch S4, the lower bridge arm power switch S5 and The initial pulse width modulation signal of the lower bridge arm power switch S6); wherein the initial pulse width modulation signal has a period of 1 / 2F.
[0047] The initial pulse width modulation signal and the pulse signal are performed, and the result of the calculation as the actual pulse width modulation signal of the six power switches; wherein the actual pulse width modulated signal is 1 / f.
[0048] Control of the six power switches based on the actual pulse width modulation signal.
[0049] Such as Figure 1 to 4 As shown, the power battery heating system in the present embodiment includes a motor system, a battery management system 2, a control system 3, a cooling liquid tank 5, and a water pump 6.
[0050] The motor system includes a motor controller 41 and a three-phase motor 42, a three-phase motor 42 is a three-phase three-wire electric machine, and the motor controller 41 includes a control module, a three-phase bridge arm and a busbar capacitor C, three-phase bridge arm U-phase bridge arm, V-phase bridge arm and W-phase bridge arms in parallel, busbar capacitance C and U-phase bridge arms, V-phase bridge arms, and W-phase bridge arms in parallel. The U-phase bridge arm is connected by the upper bridge arm power switch S1 and the lower bridge arm power switch S4, and the V-phase bridge arm is connected by the upper bridge arm power switch S2 and the lower bridge arm power switch S5, and the W phase bridge arm is from the upper bridge arm. Power switch S3 and the lower bridge arm power switch S6 connection configuration. In this implementation, the upper bridge arm power switch S1, the upper bridge arm power switch S2, the upper bridge power switch S3, the lower bridge arm power switch S4, the lower bridge arm power switch S5 and the lower bridge arm power switch S6 are IGBT modules, The bridge arm power switch S1, the upper bridge arm power switch S2, the upper bridge power switch S3, the lower bridge arm power switch S4, the lower bridge arm power switch S5, and the lower bridge arm power switch S6 have a continuous flow diode. The midpoint of the U-phase bridge arm (ie the connection point of the upper bridge arm power switch S1 and the lower bridge power switch S4) leads connects the u-phase fixing sub-winding L1 of the three-phase motor 42 (ie the upper bridge) The connection point of the arm power switch S2 and the lower bridge arm power switch S5 is connected to the midpoint of the V-phase fixing sub-winding L2 of the three-phase motor 42 (ie, the upper bridge power switch S3 and the lower bridge power switch S6) The connection point) lead is connected to the W-phase fixing sub-winding L3 of the three-phase motor 42. The motor rotor position signal output of the three-phase motor 42 (which integrates the rotor position sensor) is connected to the signal acquisition end of the control module. The upper bridge arm power switch S1, the upper bridge arm power switch S2, the upper bridge arm power switch S3 upper end lead connection power battery 1 of the positive, lower bridge arm power switch S4, the lower bridge arm power switch S5, the lower bridge arm power switch S6 The lower end lead is connected to the negative electrode of the power battery 1 to form a power battery pulse heating circuit. The control terminal of the upper bridge arm power switch S1, the control terminal of the upper bridge arm power switch S2, the control terminal of the upper bridge arm power switch S3, the control terminal of the lower bridge arm power switch S4, the control terminal of the lower bridge arm power switch S5 and The control terminals of the lower bridge arm power switch S6 are connected to the six control outputs of the control module, respectively.
[0051] The control module includes a conditional processing module, a direct axis voltage determining module, a PARK inverse transform module, a pulse signal generating module, and an SVPWM module.
[0052] The condition processing module is used to receive signals (including the pulse current size request value IREQ, pulse current frequency request value f, and motor rotor position signal), and transmit pulse current size request value IREQ to the direct axial voltage determination module in the pulse heating mode. The motor rotor position signal is sent to the PARK inverse transform module, and the pulse current frequency request value f is sent to the pulse signal generation module and the SVPWM module.
[0053] The straight axial voltage determination module is configured to obtain the current-voltage meter in the pulse current size request value IREQ query current-voltage meter, to obtain the direct axis voltage request value UD, and transmit the direct axial voltage request value UD to the PARK inverse transform module; The current-voltage meter is a corresponding relationship table obtained by the calibration method and the stored pulse current size request value to the direct axial voltage request value.
[0054] The PARK inverter module is configured to perform PARK inverse transform on the rotor position signal in the pulse heating mode, to the current axis voltage request value UD and the preset shaft voltage Uq, to obtain the α-axis voltage vector u α And β-axis voltage vectors U β , And alpha axis voltage vector u α And β-axis voltage vectors U βSend to the SVPWM module; where the preset shaft voltage UQ = 0. When the motor rotor position signal indicates that the current position of the motor rotor is θ, it is parallel to the direction D axis (ie, the straight axis) in the direction of the rotor, which is perpendicular to the rotor magnetic field as a Q axis (ie, shaft), so that the shaft voltage UQ = 0 The resulting magnetic field does not produce torque on the motor rotor, and avoids non-expected travel or jitter during pulse heating. The time to control the six power switches can be controlled by adjusting the size of the vertex voltage request value UD, thereby controlling the size of the pulse current.
[0055] The pulse signal generation module is configured to generate a pulse signal having a cycle 1 / f according to the pulse current frequency request value f in the pulse heating mode, and transmit the pulse signal to the SVPWM module; wherein the pulse signal is 1 before 1 period. / 2F time is high (ie 1), and then 1 / 2F time is low (ie 0).
[0056] The SVPWM module is used to voltage u-based voltage in the pulsed heating mode α , Β-axis voltage vector u β And the pulse current frequency request value f, generate six power switches (ie the upper bridge power switch S1, the upper bridge power switch S2, the upper bridge power switch S3, the lower bridge arm power switch S4, the lower bridge arm power switch S5 and The initial pulse width modulation signal of the lower bridge arm power switch S6), and performs the initial pulse width modulation signal and the pulse signal (multiplied), the result of the calculation as the actual pulse width modulation signal of the six power switches, and then According to the actual pulse width modulation signal, the interworking of the six power switches can be realized (a pulse current) can be realized (forming a pulse current) in accordance with the actual pulse width modulation signal; wherein the initial pulse width modulation signal is 1 / 2F, The actual pulse width modulated signal is 1 / f.
[0057] Battery management system 2 is connected to the power battery 1, the battery management system 2 and the control system 3 are connected via the CAN line. The control system 3 can request the battery management system 2 to control the relay closed within the power battery 1, so that the vehicle is high in pressure. The control system 3 is connected to the control module, and the temperature sensor is connected to the control system 3 in the motor controller 41, and the temperature sensor of the detected motor controller is transmitted to the control system 3, and the temperature sensor in the three-phase motor 42 is provided. Connect to the control system 3, the stator temperature of the detected three-phase motor is transmitted to the control system 3. The control system 3 is connected to the water pump 6, and the water pump 6 is controlled / closed. The coolant tank 5, the water pump 6, the motor controller 41, the three-phase motor 42, and the power battery 1 form a coolant circuit through a cooling line.
[0058] The motor system is used to drive the vehicle during the vehicle driving. When the motor system is in driving mode, the motor controller and the three-phase motor enters the driving mode, the control module outputs the six power switch S1 of the modulated signal to control the three-phase bridge arm according to the position signal, the speed signal, and the torque request signal feedback from the motor. The all-wheel-off (prior art) of S2, S3, S4, S5, S6, and then controls the torque required for the three-phase motor 42 to output the vehicle driving, and drive the vehicle to continue to travel.
[0059] In pulse heating mode, the operating state of the motor system is divided into two states of energy storage and continuation, in the energy storage and continuation flow state, the pulse current flows through the battery internal resistance of the power battery, the battery internal resistance is hot, in the power battery Generate heat, thereby achieving power battery pulses heating. image 3 A current flow is shown in a certain time in a certain time, when the upper bridge power switch S1, the upper bridge arm power switch S2, the lower bridge arm power switch S6 is turned on, the upper bridge arm power switch S3, When the bridge arm power switch S4, when the lower bridge arm power switch S5 is turned off, the current flows out of the positive electrode of the power battery, after the upper bridge power switch S1, the upper bridge power switch S2, flows into the U-phase fixing sub-winding L1 and V The winding L2, after the conjunction thereof, then flows out of the W-phase fixture winding L3, and the rear current flows out of the W-phase fixed sub-winding L3, and the lower bridge arm power switch S6 flows out the motor controller, and finally flows into the negative electrode of the power battery, the process can be paired with the three-phase motor 42. The U-phase fixing sub-winding L1, V corresponds sub-winding L2, and the W-phase fixing sub-winding L3 performs energy. In this state, the current on the power battery is out of the positive electrode, the negative electrode flows, by adjusting the upper bridge arm power switch S1, the upper bridge arm power switch S2, the on-time of the lower bridge arm power switch S6 can regulate the size of the pulse current, turn on The longer the time, the greater the pulse current. The energy stored in the three-phase motor's u-phase fixing L1, the V-phase fixing sub-winding L2, and the energy stored in the W-phase fixing sub-winding L3 is charged by the continuous flow circuit. Figure 4 A current flow is given in a period of time, when the upper bridge arm power switch S1, the upper bridge arm power switch S2, the upper bridge arm power switch S3, the lower bridge arm power switch S4, the lower bridge arm When the power switch S5 and the lower bridge arm power switch S6 are broken, due to the characteristics of the inductance, the current direction in the U-phase fixture windings L1, the V-phase fixing sub-winding L3 does not change immediately, and the current is from W After the corresponding sub-winding L3 flows out, the motor controller is exiting the motor controller through the upper bridge arm power switch S3, and then flows into the positive electrode of the power battery. After the power battery negative is out of the power battery, the diode of the lower bridge arm power switch S4, the lower bridge arm power The renewal diode of the switch S5 flows into the U-phase fixing sub-winding L1, the V-phase fixing sub-winding L2, thereby forming a continuation circuit. In this state, the current flowing from the positive electrode flows out of the positive electrode, the process flows through the current direction of the power battery and the storage state.
[0060] Such as Figure 5 to 7 As shown, the method of using the above power battery heating system for power cell heating includes:
[0061] Step 1, the battery management system 2 monitors the temperature and SOC of the power battery in real time, and determines whether the temperature of the power battery is less than the preset heating start temperature T1, and the SOC value of the power battery is greater than the preset heating starts the SOC value SOC1, if yes Then perform step two, otherwise proceed to step one.
[0062] Step Second, the battery management system 2 transmits a pulse heating to the control system 3 to the control system 3, and then perform step three.
[0063] Step 3, the control system 3 determines whether the vehicle is in a high pressure parking state, and does not exist in the high pressure parking state without the pulse heating failure, if yes, if yes, the step 4 is executed.
[0064] Step 4, the control system 3 determines the pulse current frequency request value F and the pulse current size request value IREQ according to the temperature of the power battery, and sends the pulse current frequency request value F and the pulse current size request value IREQ to the control module, and then perform step five . For example, the control system 3 obtains the pulse current frequency request value F and the pulse current size request value IREQ based on the temperature-frequency-current table of the power battery 1. Among them, the temperature-frequency-current table is a corresponding relationship table of the temperature and the pulse current frequency request value, the pulse current size request value, the pulse current size request value, the pulse current size request value, the temperature-frequency-current table is obtained by calibration mode. The corresponding relational table divides the pulse heating into three gear positions: high-grade, the temperature of the power battery is below -20 ° C, corresponding to a set of pulse current frequency request value, pulse current size request value; mid-200, power battery temperature is -20 ° C ~ -10 ° C, corresponding to a set of pulse current frequency request values, pulse current size request value; low-grade, battery temperature is greater than -10 ° C, corresponding to a set of pulse current frequency request values, pulse current size request value.
[0065] Step 5, the motor system enters the pulse heating mode, the control module outputs the corresponding current waveform according to the pulse current frequency request value f and the pulse current size request value IREQ output (see see Figure 7 ), Pulse the power battery, then perform step six.
[0066] Step 6, the control system 3 controls the water pump 6 to work, the cooling liquid of the absorbent motor controller 41 and the three-phase motor 42 enters the power battery 1 in the cooling line of the power battery 1, and then performs step seven. However, the control system 3 controls the water pump 6 during operation, the rotational speed of the water pump 6 is adjusted, and the specific adjustment method is: the control system 3 the temperature of the power battery and the temperature of the motor controller, the temperature of the power battery and the stator temperature. The larger value in the temperature difference reference value is ΔT; the control system 3 queries the temperature difference-speed table according to the temperature difference reference value Δt, to obtain the rotational speed N of the water pump 6; the control system 3 controls the water pump 6 to operate according to the rotational speed N; wherein the temperature difference - speed The table is a correspondence table of the temperature difference reference value obtained by the calibration method and the rotational speed of the water pump. The larger the temperature difference reference value Δ T, the greater the heat generation amount of the motor system, the more heat heating by the coolant to the power battery, the greater the speed N of the water pump 6.
[0067] Step 7. The control system 3 determines whether the vehicle is traveling or a pulse heating fault, if yes, then perform step eight, otherwise the steps are performed.
[0068] Step 8. The control system 3 causes the pulse current frequency request value F and the pulse current size request value IREQ to zero, and then performs step elements.
[0069] Step 9. The battery management system 2 determines whether the temperature of the power battery is greater than or equal to the preset heating stop temperature T2 (T2> T1), or the SOC value of the power battery is smaller than or equal to the preset heating stop SOC value SOC2 (SOC2
[0070] Step 10, the battery management system 2 transmits a pulse heating stop request to the control system 3, and the control system 3 makes the pulse current frequency request value f and the pulse current size request value IREQ is zero when receiving the pulse heating stop request. One.
[0071] Step 11. The control module stops the output corresponding current waveform, the motor system exits the pulse heating mode, and then performs step twelve.
[0072] Step 12, the control system 3 controls the water pump 6 to close (water pump stop operation), the cooling liquid in the cooling line of the power battery 1 stops heating the power battery due to stopping the flow, and then ends (i.e., the heating process of the power battery).
[0073] This embodiment also provides an electric vehicle including the power battery heating system.
