ELECTRIC POWER CONVERTER

摘要

An electric power conversion unit of an electric power converter establishes two converter circuits including four switching elements and two batteries and carries out electric power conversion in a parallel mode in which the batteries are connected in parallel with each other. A controller is configured to set a control signal for each of the switching elements, identify a target switching element of which a temperature is suppressed, determine a state having a maximum loss value in correspondence with input-output data, and execute phase control for suppressing the maximum loss value.

主权项

1. An electric power converter comprising:
a first battery; a second battery; a plurality of switching elements; and a controller configured to execute ON-OFF control over the plurality of switching elements, wherein the electric power converter has a parallel mode and a series mode, the electric power converter is able to switch between the parallel mode and the series mode, in the parallel mode, electric power conversion between the first battery and an output power line and electric power conversion between the second battery and the output power line are individually carried out and the two electric power conversions are carried out in parallel with each other, in the series mode, electric power conversion between both the first battery and the second battery and the output power line is carried out while the first battery and the second battery are connected in series with each other, and wherein the controller is configured to:
(i) in the parallel mode, control the electric power conversion between the first battery and the output power line with the use of a first PWM signal, control the electric power conversion between the second battery and the output power line with the use of a second PWM signal, determine an ON-OFF state of each of the plurality of switching elements based on a combination of a first signal, which is the first PWM signal or an inversion signal of the first PWM signal, and a second signal, which is the second PWM signal or an inversion signal of the second PWM signal, and set each of the switching elements in the ON state when the corresponding first signal or the corresponding second signal is in an ON state;(ii) determine a specific one of the plurality of switching elements, of which the number of switching times is suppressed;(iii) set a control phase of the first signal and a control phase of the second signal; and(iv) when the electric power converter operates in the parallel mode, set a phase difference between the first signal and the second signal for the specific switching element such that the second signal enters the ON state in a period in which the first signal is in the ON state or set the phase difference between the first signal and the second signal for the specific switching element such that the first signal enters the ON state in a period in which the second signal is in the ON state.