DIGITAL DEVICE FOR MEASURING VOLTAGE HARMONIC FACTOR Russian patent published in 1995 - IPC

FIELD: measurement technology. SUBSTANCE: device has scaler 1, phase switch 3, analog-to-code converter 4, storage unit 5, control unit 6, counters 7,8, multipliers 14, 20, 21, 22, read-only storage 15, cosine function implementing unit 16, sine function implementing unit 18, accumulating adders 27, 28, adder 31, squarer 34, dividing unit 39, arc tangent function implementing unit 46, sign identifier 47, and recording unit 44. Invention is distinguished by introduction of forward-sequence voltage component discriminating unit 2, complementing flip-flop 9, first to fourth switches 10 through 13, second cosine function implementing unit 17, second sine function implementing unit 19, fifth to ninth multipliers 23, 24, 25, 42, 43, third to fifths accumulating adders 29, 30, 37, second and third adders 32, 33, multiplexer 26, demultiplexer 35, second squarer 36, square-root extracting unit 38, second and third dividing units 40, 41. Unit 2 is to be better built up of three-phase isolating transformer 48, adder 49, and 90 deg. phase shifter 50. EFFECT: enlarged functional capabilities, improved measurement accuracy. 2 cl, 1 dwg