Servo Power Amplifier Design

Referring to the characteristics of large loading rotarv inertia, high angularvelocity and high control accuracy about controlled member, large power driver wasdesigned and its reliability was analyzedCombined with the properties of isolated-gate bipolar transistors (IGBT), Pulseduration modulation (PWM) in the power driver was applied to change the duty ratioof voltage for the purpose of controlling the rotational speed of motorsServo-actuator control circuit, including signal generator, pulse distributor circuit,signal driver circuit and power conversion circuit. Signal generator and pulsedistributor circuit are programmed with DSP. And the paper mainly focuses on signaldriver circuit and power conversion circuit. Signal driver designed has drive current of6A and common stop time is signal output of 500ns without time delay, which avoidssimultaneous connection of pipe in the same side of H-bridge circuit.Signal driver carries out the self-protective function of short-circuit current in10μs, which overcomes system function disabler caused by short-circuitInterference among systems is reduced by absorbing overvoltage on powermodule.H-bridge circuit was used in power conversion circuit, which has the advantagesof low power consumption and high effectiveness.Interface between weak signal and strong signal is isolated by voltagetransformer. Different ground wires were connected to avoid mutual interference ofsystem different parts in accordance with the classification.According to the requirements of output torque, angle velocity and acceleratedspeed, current output of Servo-power amplifier is 100A and output rotary inertiareached 200kg.m~2Power driver system designed in this paper has good linear characteristics, whichis used in tracking system. Large power conversion circuit performed with higheffectiveness and reliability whatever the system tracks and captures.Result shows that Servo-power amplifier can meet the demands of trackingvelocity and accuracy of system completely.