Voltage measuring equipment in power grids often requires capacitive voltage dividers to realize conversion of high voltage electrical quantities to low voltage signal quantities. The new floating-ground capacitive voltage divider (FG-CVD) can eliminate original lumped capacitors and its supporting insulation structures by adopting precisely designed parasitic capacitance as a high voltage arm capacitor

which can greatly save cost and volume. However

the utilization of parasitic capacitance not only makes FG-CVD sensitive to external conductor interference

but also causes transient waveform distortion

especially when the connecting lead between the FG-CVD and high-voltage conductor is lengthy. On the basis of transfer characteristic analysis

this paper proposes a complete parameter design method for FG-CVD to improve stability of its transfer ratio under interference of the external conductor. Moreover

by establishing a wideband equivalent model with lead inductance

the transient waveform distortion problem of FG-CVD is well explained

and a resistance compensation scheme is also proposed to reduce ratio error. Finally

a 500:1 FG-CVD prototype with a measurement bandwidth of 2MHz is developed. Experimental results show the prototype has high accuracy in both power frequency and lightning pulse voltage measurement

and ratio error decreases from 20.33% to less than 1.3%.