Research On High-pressure Piezoelectric Ceramic Driving Power

The positive and inverse piezoelectric effect of piezoelectric ceramics make thepiezoelectric ceramic drive techology play an important role in the field of micro-displacement position. In order to obtain the accurate micro-displacement positioning,piezoelectric amplifier should have low ripple output, high frequency response andfast dynamic response, so the design of piezoelectric amplifier becomes the core ofthe research in the micro positioning system at home and abroad. At present most ofpiezoelectric amplifiers are driven by linear power, caused huge power loss, bigvolume and low power dissipation. To overcome the above defects and achieve thespecific piezoelectric amplifier requirements, a kind of PWM drive way is designedin this thesis, the output waveform is frequency and amplitude modulated sine wavewith DC bias.This piezoelectric ceramic actuator is mainly composed of booster DC/DCconverter and inverter DC/AC circuit. The front-end circuit required to translate thelevel of low fuel voltage (30V~42V)to meet the high voltage380V, load-connectedinverter produces a peak of300V sine wave, superposition with the isolated boosterbus bar to generate sine wave with DC bias.For battery power system, a current-fed interleaved transformer-isolatedDC/DC converter with active clamping circuit is presented, which can provide a highset-up voltage ratio and decrease the input-output current ripple. The interleavingtopology reduces the volume and weight of the device, maintains high efficiency, theactive clamping circuit can not only absorb voltage spike of the primary side oftransformer and also assists in achieving ZVS of all switches under wide variation ininput voltage. In addition the gating signals of auxiliary switches are complementaryto the corresponding main switch gating signals, so it does not need to add additionaldrive circuit. Detailed analysis and operation of the converter is presented,researching the buffer circuit and the condition to realize soft switch, it also give thedetailed circuit parameters. A closed loop control design using state-space averagingtechnique to get the mall-signal control model is presented. A PI control method isimplemented, simulation results of PSIM are presented at different input voltageconditions.The load-connected full bridge inverter operated using traditional bipolarSPWM control strategy. A two-loop voltage controller is designed for lower outputvoltage distortion and the accuracy of sine wave. By using PSIM simulation software,the control system of the inverter circuit is simulated.Based on the theoretical analysis and simulation verification, using TMS320F2812as the core controller, an experimental platform has been set up andtested to verify the validity and performance of the proposed converter.