Multi-phase power converter control

A controller for a multi-phase power converter, the multi-phase power converter comprising at least one pulse width modulation (PWM) inverter module for each phase, the controller comprising:

• an input unit configured to receive a voltage reference value for each phase, and
• a processing unit configured to:
• check, for each pair of phases, whether a difference between the corresponding pair of voltage reference values is below a predetermined threshold value,
• generate a modified voltage reference value for each phase by modifying the received voltage reference values in such a way that the difference between each pair of modified voltage reference values is equal to or larger than the predetermined threshold value, and
• generate PWM switching signals for the PWM inverter modules based on the modified voltage reference values,
• wherein the processing unit is configured to modify the received voltage reference values for one pair of phases, for which the difference is below the predetermined threshold value, by:
• calculating a voltage shift value based on the difference and the predetermined threshold value,
• adding the voltage shift value to the voltage reference value corresponding to one phase of the pair of phases, and
• subtracting the voltage shift value from the voltage reference value corresponding to the other phase of the pair of phases,
• wherein the input unit is configured to receive a further voltage reference value for each phase, and wherein the processing unit is configured to:
• adjust the further voltage reference value for each phase based on the corresponding voltage shift value,
• check, for each pair of phases, whether a further difference between the corresponding pair of adjusted further voltage reference values is below the predetermined threshold value,
• generate a modified further voltage reference value for each phase by modifying the adjusted further voltage reference values in such a way that the further difference between each pair of modified further voltage reference values is equal to or larger than the predetermined threshold value, and
• generate further PWM switching signals for the PWM inverter modules based on the modified further voltage reference values,
• wherein the processing unit is configured to adjust the further voltage reference value for each phase by:
• subtracting the voltage shift value from the further voltage reference value if the voltage shift value was added to the voltage reference value of that phase when modifying the voltage reference values, and
• adding the voltage shift value to the further voltage reference value if the voltage shift value was subtracted from the voltage reference value of that phase when modifying the voltage reference values.