High-voltage power amplifier based on multi-unit cascade for piezoelectric actuators

In order to improve the dynamic performance, load capacity and the bandwidth of a piezoelectric amplifier, a high-voltage power amplifier based on multi-unit cascade was developed. First, a high-precision amplifier unit based on discrete components was designed and a series of models for every driving units were simulated. Then, the stability of the amplifier unit in a piezoelectric capacitive load was analyzed and a effective dual-channel feedback compensation strategy was given. Furthermore, based on multi-unit floating cascade topology, a novel combined high-voltage piezoelectric amplifier was developed by cascading the multiple independent high-precision piezoelectric amplifier unit. Experimental results indicate that the cascade amplifier can offer the output voltage amplitude of 0~1000 V, maximum output power of 1 kW, large signal bandwidth over 1 kHz/0.3 μF, and the static ripple of 100 mV. It concludes that the amplifier can satisfy the system requirements of low ripple, high accuracy, large bandwidth, short response time and good load capacity.