A triple phase-shift control method for a DC-DC bidirectional power supply with a dual active bridge topology

Abstract

The present invention discloses a triple phase-shift control method for a dual-active-bridge-topology DC-DC bidirectional power supply. The method comprises collecting voltage and current information from the input and output ends of the dual-active-bridge-topology DC-DC bidirectional power supply; selecting the power transmission direction of the dual-active-bridge-topology DC-DC bidirectional power supply and selecting a constant voltage output mode or a constant current output mode according to a preset operating mode; setting a set value for the output of the constant voltage output mode or the constant current output mode; and the dual-active-bridge-topology DC-DC bidirectional power supply outputting a constant voltage value or a constant current value that matches the set value in the correct power transmission direction according to the preset operating mode. This method can effectively address the problem of large current distortion spikes in energy storage inductors, greatly improving the operating efficiency of the DC-DC power supply module and the service life of power components.

Claims

1. A triple phase shift control method for a DC-DC bidirectional power supply with a dual active bridge topology, characterized in that: include: The voltage and current information of the input and output ends of the DC-DC bidirectional power supply with dual active bridge topology are collected respectively; According to the preset working mode, the power transmission direction of the dual active bridge topology DC-DC bidirectional power supply is selected and the constant voltage output mode or the constant current output mode is selected; wherein, the control logic of the constant voltage loop of the dual active bridge topology structure includes sampling the input voltage and the output voltage, and outputting them together with the set voltage value to the MCU, the MCU calculating the voltage modulation index of the sampled voltage and the voltage modulation index of the set voltage, and sending the difference between the voltage modulation index of the sampled voltage and the voltage modulation index of the set voltage into the anti-integral saturation position formula PI to calculate the output transmission normalized reference power, and then sending it into the three-phase shift ratio calculation function f(m, p) to calculate the three phase shift duty ratios required for PWM modulation for modulation; the control logic of the constant current loop of the dual active bridge topology structure includes taking the difference between the set output current and the actual sampled current as the input of the anti-integral saturation position formula PI loop and calculating it, and using the calculated result as the voltage value of the preset value to calculate the voltage modulation index of the set voltage; Set the output value of constant voltage output mode or constant current output mode; The dual active bridge topology DC-DC bidirectional power supply outputs a constant voltage value that is consistent with a set value in a correct power transmission direction according to a preset working mode, including: The collected input voltage information, output voltage information and voltage setting value for setting constant voltage output mode are transmitted to the MCU to calculate the voltage modulation index of the sampled voltage and the voltage modulation index of the set voltage; Subtract the calculated voltage modulation index of the sampled voltage from the voltage modulation index of the set voltage; The difference is calculated by the anti-integral saturation position PI loop and then the normalized reference power is output after the Ramp function is calculated; The calculated normalized reference power is subjected to three phase shifts and compared with the three phase shift duty ratios required for PWM modulation in the calculation function f(m,p); Perform PWM modulation according to the calculated three phase-shift duty cycles and output a constant voltage value; The steps of outputting a constant current value that matches a set value in a correct power transmission direction according to a preset working mode of the dual active bridge topology DC-DC bidirectional power supply include: The set current value is calculated by the Ramp function and then the difference is calculated from the output current value collected by the ADC sampling module. The difference is then processed by the anti-integral saturation position PI loop to calculate the output reference voltage. The collected input voltage information and output voltage information are transmitted to the MCU to calculate the voltage modulation of the sampled voltage, and the output reference voltage is calculated by the ramp function and then combined with the collected input voltage information to calculate the voltage modulation of the set voltage; Subtract the calculated voltage modulation index of the sampled voltage from the voltage modulation index of the set voltage; The difference is transmitted to the anti-integral saturation position formula for PI calculation and outputs the normalized reference power after calculation by the Ramp function; The calculated normalized reference power is subjected to three phase shifts and compared with the three phase shift duty ratios required for PWM modulation in the calculation function f(m,p); Perform PWM modulation according to the calculated three phase-shift duty ratios and output a constant current value; The dual active bridge topology DC-DC bidirectional power supply outputs a constant voltage or constant current value that matches the set value in the correct power transmission direction according to the preset working mode; The anti-saturation position PI loop calculation satisfies the following relationship: ； ； ； ； in, is the output at the nth moment, To set the PI proportional parameter, To set the PI integral parameters, is the error amount input at the nth moment, To reach the upper and lower limits of PI output The final calculated value of and The upper and lower limits of the PI output.

2. The triple phase-shift control method for a dual active bridge topology DC-DC bidirectional power supply according to claim 1, characterized in that: In the steps of respectively collecting the voltage and current information of the input and output ends of the dual active bridge topology DC-DC bidirectional power supply, the ADC sampling module of the MCU is used to collect the voltage and current information of the input and output ends.

3. The triple phase-shift control method for a dual active bridge topology DC-DC bidirectional power supply according to claim 1, characterized in that: The voltage modulation degree satisfies the following relationship: ； Among them, m is the voltage modulation index, k is the transformer ratio, Vin is the input voltage, and Vout is the output voltage.

4. The triple phase-shift control method for a dual active bridge topology DC-DC bidirectional power supply according to claim 3, characterized in that: The three-phase shift phase shift ratio calculation function f(m,p) satisfies the following relationship: when and hour, ； Where m is the voltage modulation index, d1, d2, and d3 are the three phase-shift duty cycles required for PWM modulation calculated by the f(m, p) function, and p is the normalized transmission power, with a range of [0, 1].

5. The triple phase-shift control method for a dual active bridge topology DC-DC bidirectional power supply according to claim 4, characterized in that: The three-phase shift ratio calculation function f(m,p) also satisfies the following relationship: when and hour, ； Where m is the voltage modulation index, d1, d2, and d3 are the three phase-shift duty cycles required for PWM modulation calculated by the f(m, p) function, and p is the normalized transmission power, with a range of [0, 1].

6. The triple phase-shift control method for a dual active bridge topology DC-DC bidirectional power supply according to claim 5, characterized in that: The three-phase shift ratio calculation function f(m,p) also satisfies the following relationship: when and hour, ； Where m is the voltage modulation index, d1, d2, and d3 are the three phase-shift duty cycles required for PWM modulation calculated by the f(m, p) function, and p is the normalized transmission power, with a range of [0, 1].

7. The triple phase-shift control method for a dual active bridge topology DC-DC bidirectional power supply according to claim 6, characterized in that: The three-phase shift ratio calculation function f(m,p) also satisfies the following relationship: when and hour, ； Where m is the voltage modulation index, d1, d2, and d3 are the three phase-shift duty cycles required for PWM modulation calculated by the f(m, p) function, and p is the normalized transmission power, with a range of [0, 1].

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