OPEN DETECTION DEVICE AND OPEN DETECTION METHOD

• Main Authors: SATO AKIRA, KANEDA TAKAHIRO
• Format: Patent
• Language: English; Japanese
• Published: 25.03.2021
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

To provide an open detection device capable of detecting a primary-side open and a secondary-side open in a distinguishable manner, and an open detection method.SOLUTION: An open detection device comprises: a current transformer CT1 which detects an inverter output current; an effective value calculation unit 12 which calculates an effective value of the inverter output current; an instantaneous effective value calculation unit 11 which calculates a value adding a square of the inverter output current and a square of a differential value of a target current as an instantaneous current effective value at an interval shorter than an interval of the effective value calculation by the effective value calculation unit; a state determination unit 13 while outputs a reduction signal instructing that an output current is reduced from an output current command value to an open-circuit verification current value in the case where the instantaneous current effective value is smaller than a preset first threshold current value; and an open-circuit determination unit 14 which detects a primary-side open-circuit in the case where the current effective value is smaller than a second threshold current value in the state where the output current is reduced to the open-circuit verification current value in accordance with the reduction signal.SELECTED DRAWING: Figure 1 【課題】１次側のオープンを２次側のオープンと区別して検出することができるオープン検出装置及びオープン検出方法を提供する。【解決手段】インバータ出力電流を検出する変流器ＣＴ１と、インバータ出力電流の実効値を演算する実効値演算部１２と、インバータ出力電流流の２乗と対象電流の微分値の２乗とを加算した値を瞬時電流実効値として、実効値演算部による実効値の演算間隔よりも短い間隔で演算する瞬時実効値演算部１１と、瞬時電流実効値が予め設定された第１閾電流値を下回った場合、出力電流を出力電流指令値から開路検証電流値に引き下げることを指示する削減信号を出力する状態判定部１３と、削減信号によって出力電流が開路検証電流値に引き下げられた状態で、電流実効値が第２閾電流値を下回った場合、１次側の開路を検出する開路判定部１４とを備えている。【選択図】図１