Development of a Digital Wattmeter for Distorted Wave Using DSP
Takafumi FUJISAWA, Kazuhiro ABE
The authors have been engaged in the development of a wide frequency range wattmeter utilizing a Digital Signal Processor ; with input terminals being made up of voltage/current sensors of magnetic balance type.
In general, measurements errors are attributed to the measuring interval “T”, the measured voltage and/or current frequency. However, this error can be reduced to minimum by setting T to integer multiples of the AC voltage period.
They propose, in this paper, a procedure and a DSP control program to reduce measurement error. Experimental results are given to illustrate the efficiency of this error reduction system.