Disclosure of Invention
The invention aims to provide a battery pulse heating control system, a battery pulse heating control method, a vehicle and a storage medium, so that the pulse heating efficiency of a power battery is improved, and the safety and the reliability of the hardware of a motor controller are ensured.
In a first aspect, the present invention provides a battery pulse heating control method, including the steps of:
after detecting that the pulse heating of the power battery starts, detecting whether a hardware overcurrent fault occurs through a motor controller:
if the motor controller does not report the hardware overcurrent fault, increasing the current of the power battery during pulse heating, wherein the specific mode of increasing the current of the power battery during pulse heating is as follows: reducing the PWM wave switching frequency f and increasing Ud and Uq, wherein Ud is direct axis voltage under a motor rotating coordinate system, and Uq is quadrature axis voltage under the motor rotating coordinate system;
if the motor controller reports the hardware overcurrent fault, reducing the pulse heating current of the power battery, wherein the specific mode of reducing the pulse heating current of the power battery is as follows: increasing the PWM wave switching frequency f and reducing Ud and Uq;
the PWM wave switching frequency f, Ud and Uq corresponding to the hardware maximum current are searched through the hardware overcurrent fault state of the motor controller.
Optionally, when the motor controller reports the hardware overcurrent fault, the number of faults is recorded.
Optionally, after detecting the start of the pulse heating of the power battery, the method further includes:
judging whether the failure times are less than or equal to preset times;
if the fault frequency is less than or equal to the preset frequency, detecting whether a hardware overcurrent fault occurs through the motor controller, continuously adjusting the PWM wave switching frequency f, the Ud and the Uq, and searching the maximum current state of the hardware;
if the fault frequency is greater than the preset frequency, the current PWM wave switching frequency f, Ud and Uq are considered to be the PWM wave switching frequency f, Ud and Uq corresponding to the maximum hardware current, and the current PWM wave switching frequency f, Ud and Uq are maintained; in order to prevent false triggering of the overcurrent fault, a mode of multiple judgment is adopted.
Optionally, the method further comprises:
setting the overcurrent fault of the hardware of the motor controller as a recoverable fault, clearing the fault before increasing the switching frequency f of the PWM wave and reducing the Ud and the Uq, and adding 1 to the number of the faults.
Optionally, the PWM duty ratio is kept within a preset value while increasing and decreasing the PWM switching frequency f and adjusting Ud and Uq, so as to ensure that the three-phase current proportion is unchanged and the motor output torque is zero.
In a second aspect, the present invention provides a battery pulse heating control system, which includes a memory and a controller, wherein the memory stores a computer readable program, and the computer readable program, when called by the controller, can execute the steps of the battery pulse heating control method according to the present invention.
In a third aspect, the invention provides a vehicle, which adopts the battery pulse heating control system.
In a fourth aspect, the present invention provides a storage medium having a computer readable program stored therein, wherein the computer readable program is capable of executing the steps of the method for controlling pulse heating of a battery according to the present invention when the computer readable program is called.
The invention has the following advantages: according to the invention, the current of the power module is regulated in a closed loop manner by utilizing a hardware overcurrent protection mechanism of the motor controller, so that the pulse heating current of the battery is controlled to the maximum extent, the pulse heating efficiency of the power battery is improved, and the safety and reliability of the hardware of the motor controller are ensured.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings.
Example one
As shown in fig. 1, in this embodiment, a method for controlling pulse heating of a battery includes the following steps:
step A1, after the start of pulse heating of the power battery is detected, whether a hardware overcurrent fault occurs is detected through a motor controller.
A2, if the motor controller does not report the hardware overcurrent fault, increasing the current of the power battery during pulse heating, and returning to the step A1; the specific way of increasing the current of the power battery during pulse heating is as follows: and reducing the switching frequency f of the PWM wave, and increasing Ud and Uq, wherein Ud is the direct axis voltage of the motor rotating coordinate system, and Uq is the quadrature axis voltage of the motor rotating coordinate system.
A3, if the motor controller reports the hardware overcurrent fault, reducing the pulse heating current of the power battery, and returning to the step A1; the specific way of reducing the pulse heating current of the power battery is as follows: increasing the PWM wave switching frequency f and decreasing Ud and Uq.
In this embodiment, the PWM wave switching frequencies f, Ud, and Uq are continuously adjusted according to the hardware overcurrent fault state detected by the motor controller, and the PWM wave switching frequencies f, Ud, and Uq corresponding to the hardware maximum current are found. For NVH consideration, the PWM wave switching frequency f is a frequency range within which a larger current can be obtained and a better NVH experience.
According to the formula Q = I 2 Rt, the amount Q of heat generation of the battery internal resistance Rt is proportional to the square of the current I, and therefore, the charging and discharging current of the battery during pulse heating is increased, and the efficiency of pulse heating can be improved. The rising slope of the pulse current is limited by the motor inductance, and under the condition that the motor inductance is fixed, the current value can be increased from two directions of adjusting the PWM wave switching frequency f and the duty ratio in order to increase the current. The duty ratio is calculated by Ud and Uq according to the bus voltage and the principle of vector control. In this embodiment, the PWM switching frequency f is increased or decreased, Ud and Uq are adjusted, and the PWM maximum duty ratio is kept within a certain value (e.g., 90%), so as to ensure that the three-phase current ratio is unchanged and the motor output torque is zero. The method comprises the steps ofThe accurate control of the PWM switching frequency and the PWM duty ratio ensures the high efficiency of the pulse heating of the power battery.
In this embodiment, a battery pulse heating control system includes a memory and a controller, where the memory stores a computer readable program, and the computer readable program, when called by the controller, can execute the steps of the battery pulse heating control method as described in this embodiment.
In the present embodiment, a vehicle employs the battery pulse heating control system as described in the present embodiment.
In this embodiment, a storage medium stores a computer readable program, and the computer readable program when called can execute the steps of the battery pulse heating control method as described in this embodiment.
Example two
As shown in fig. 2, in this embodiment, a method for controlling pulse heating of a battery includes the following steps:
step B1, after the pulse heating of the power battery is detected to be started, judging whether the failure times are less than or equal to preset times, and if the failure times are less than or equal to the preset times, entering step B2; if the number of failures is greater than the preset number, the process proceeds to step B3.
Step B2, detecting whether a hardware overcurrent fault occurs through the motor controller, continuously adjusting PWM wave switching frequency f, Ud and Uq, and searching the maximum current state of the hardware; the method specifically comprises the following steps:
if the motor controller does not report the hardware overcurrent fault, reducing the PWM wave switching frequency f, increasing the Ud and the Uq, and returning to the step B1;
if the motor controller reports the hardware overcurrent fault, the fault is cleared, the number of the faults is added by 1, the PWM wave switching frequency f is increased, the Ud and the Uq are reduced, and the step B1 is returned;
and step B3, keeping the current PWM wave switching frequencies f, Ud and Uq if the current PWM wave switching frequencies f, Ud and Uq are the PWM wave switching frequencies f, Ud and Uq corresponding to the hardware maximum current.
In this embodiment, a multiple-time judgment mode is adopted, which aims to prevent an overcurrent fault from being triggered by mistake, that is, after the start of pulse heating of a power battery is detected and the number of faults is greater than a preset number, current PWM wave switching frequencies f, Ud and Uq are maintained; otherwise, continuously adjusting the PWM wave switching frequency f, Ud and Uq until finding the PWM wave switching frequency f, Ud and Uq corresponding to the hardware maximum current so as to ensure that the motor controller works in the maximum current state.
In this embodiment, the hardware overcurrent fault of the motor controller is set to be a recoverable fault, and the number of times of the fault is increased by 1 while the fault is cleared.
According to the method, after the PWM wave switching frequency, the Ud and the Uq are continuously adjusted, and the hardware overcurrent fault is repeatedly triggered and recovered, the maximum current value which can be output in the current state and the corresponding PWM wave switching frequency f, the Ud and the Uq can be locked. At the moment, the hardware current of the motor controller is close to the maximum allowable current, and the pulse heating current of the power battery reaches the maximum.
As shown in fig. 3, the three-phase current waveforms Ia, Ib, and Ic, the dc current waveform Idc, the PWM wave switching frequency f, the direct-axis voltage Ud, and the quadrature-axis voltage Uq are sequentially mapped from top to bottom, where the abscissa in fig. 3 represents time. As can be seen from fig. 3, after the start of pulse heating of the power battery is detected, firstly, a downward optimization method is adopted for the PWM wave switching frequency f, the PWM wave switching frequency f is continuously reduced, when the PWM wave switching frequency f is reduced to a certain value, an overcurrent fault occurs in the hardware at this time, if the current fault frequency is less than a preset frequency, the fault is cleared, the fault frequency +1 is added, the PWM wave switching frequency f is appropriately increased, and the above steps are repeated until the fault frequency reaches the preset frequency, which indicates that the PWM wave switching frequency f, Ud and Uq corresponding to the maximum current of the hardware have been found.
The rest is the same as the first embodiment.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.