MULTICIRCUIT TYPE INSTRUMENT AND SPLIT TYPE CURRENT TRANSFORMER FOR USE IN MEASUREMENT THEREOF

摘要

Abstract of the DisclosureThe multicircuit type instrument of the invention is designed tomeasure the electric power, electric energy, power factor, reactive power, and reactive energy of one or more voltage Lines of alternating-currentthree-phase electric circuit or alternating-current single-phase electriccircuit, and circuits branched off from these voltage lines.The multicircuit type watt meter of the invention includes at least one line or more of voltage input means of alternating-current three phase electric circuit or alternating-current single-phase electric circuit,current input means in the same number of voltage input means or more,input switching means for switching over the current input means, an A/Dconverter converting an analog output of the voltage input means and ananalog output of the current input means into digital signals, and a CPU for controlling switching of the input switching means and controlling timeshared multiplex sampling of the A/D converter, in which the current inputmeans connected to the input switching means are switched over sequentially by the input switching means between a sampling point and a next sampling point in the basic time shared sampling of time shared multiplex performed by the CPU, and by performing time shared samplingsame as the basic time shared sampling in cooperation with each switching, different circuits are sequentially sampled by time sharing, so that the plural electric power values are computed by the CPU from thesimultaneous time shared sampling data.The CPU computes, instead of the electric power, the electric 25 energy, power factor, reactive power and reactive energy, so that themulticircuit type instrument of the invention may be used also as thewatthour meter, power factor meter, reactive power meter, or var-hourmeter. Fig. 13 84