TEST DEVICE FOR WATTHOUR METER

PROBLEM TO BE SOLVED: To provide a test device capable of an actual load test of a watthour meter using an existing test power source.SOLUTION: A test device includes: a voltage circuit for connecting voltage terminals of a plurality of watthour meters WH to be tested with a voltage source VS; and a current circuit for connecting current terminals of the watthour meters to be tested with a current source CS via an insulated current transformer CT. The test device performs an actual load test by supplying voltage and current to the watthour meters to be tested. The test device comprises: a current detector CTfor detecting current i supplied to the insulated current transformer by the current source; a current/voltage converter I/V for forming a voltage signal vcorresponding to the current detected by the current detector; and a negative impedance circuit NI for amplifying a compensation voltage signal and supplying it to the current circuit so as to compensate a voltage drop due to impedance of the insulated current transformer. Alternatively, the test device may use a voltage detector instead of the current detector, and a voltage-to-voltage converter V/V instead of the current/voltage converter.SELECTED DRAWING: Figure 1 【課題】既存の試験用電源を用いて電力量計を実負荷試験し得る試験装置を提供すること。【解決手段】複数の被試験電力量計ＷＨの電圧端子を電圧源ＶＳに接続する電圧回路と、絶縁変流器ＣＴｉを介して前記被試験電力量計の電流端子を電流源ＣＳに接続する電流回路とを有し、前記被試験電力量計に電圧、電流を与えて実負荷試験する試験装置において、前記絶縁変流器に対し前記電流源から供給される電流ｉを検出する電流検出器ＣＴｄと、この電流検出器の検出した電流に応じた電圧信号ｖｓを形成する電流／電圧変換器Ｉ／Ｖと、前記補償用電圧信号を増幅して前記電流回路に対し前記絶縁変流器のインピーダンスによる電圧降下分を補償するように供給する負性インピーダンス回路ＮＩとをそなえた試験装置。又は、前記電流検出器の替わりに電圧検出器を、前記電流／電圧変換器の替わりに電圧・電圧変換器Ｖ／Ｖを用いたもの。【選択図】図１