The Precision Of The Digital Power Voltage Measurement Signal Amplification System

This paper presents a digital high precision signal power amplifier applied in the second winging of CVT for the high AC voltage measure in Power System and analyses the intrinsic problem and disadvantage of CVT applied in power voltage measure system, based on the status in quo of CVT applied in power system.This digital amplifier made up of a digital inverter can implement the sine voltage signal's power amplifying based on the digital signal processor. With the high processing ability of DSP, the advanced digital control arithmetic can be realized in the software. Also the feasible and effective technique for the time delay compensation of digital control can be achieved. The high capability and precision of the inverter amplifier is a good attempt to resolve the problem which mainly features the little load capability in CVT.The digital inverter amplifier is controlled by the DSP chip TMS320FL240. The high performance of digital voltage and current control loops and the improved digital PI control arithmetic based on the current prediction techniques is achieved in the software. And the dead-time of inverter also is compensated. This digital inverter amplifier's DC power is supplied by an AC/DC with PFC circuit controlled by 3854. In the end, the experimental conclusion based on the compare prototype of the input voltage signal and the output power amplified voltage signal and a model is presented.