LLCC-PWM inverter for driving high-power piezoelectric actuators

In this contribution a novel LLCC-PWM inverter is presented for driving ultrasonic high power piezoelectric actuators. The proposed system of a pulse-width modulated inverter and LLCC-type filter is designed in a way to reduce the total harmonic distortion of the motor voltage and to locally compensate for the reactive power of piezoelectric actuators. In order to limit the switching frequency, a pulse width modulation using elimination technique of selected harmonics is designed and implemented on a FPGA. Due to local compensation of reactive power and high dynamic behavior of LLCC PWM inverter, the whole power supply shows an optimal performance at minimized volume and weight compared to LC and LLCC resonant converters.