POWER CONVERSION DEVICE

• Main Authors: NISHIO MOTOKI, KUBOTA YOHEI, ARAI TAKURO
• Format: Patent
• Language: English; Japanese
• Published: 05.04.2023
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

To provide a power conversion device which is capable of preventing destruction of a switch element or lifetime reduction of a capacitor and improved in reliability.SOLUTION: A power conversion device comprises: a multilevel converter connected to each of power supply lines of a three-phase AC power source and each configured by connecting a plurality of unit converters in series; and control means. The control means detects a harmonic component of a current flowing to a load, calculates a compensation current which should flow to each power supply line in order to suppress the harmonic component, controls an output voltage of the multilevel converter so as to obtain the compensation current, and controls a value of the compensation current in such a manner that an actual value of a current flowing between each power supply line and the multilevel converter is settled at a threshold.SELECTED DRAWING: Figure 1 【課題】 スイッチ素子の破壊やコンデンサの寿命低下を防ぐことができる信頼性にすぐれた電力変換装置を提供する。【解決手段】 電力変換装置は、三相交流電源の各電源ラインに接続されそれぞれが複数の単位変換器を直列接続してなるマルチレベル変換器と、制御手段とを備える。制御手段は、前記負荷に流れる電流の高調波成分を検出し、その高調波成分を抑制するために前記各電源ラインに流すべき補償電流を求め、その補償電流が得られるよう前記マルチレベル変換器の出力電圧を制御するとともに、前記各電源ラインと前記マルチレベル変換器との間に流れる電流の実効値が閾値に収まるよう前記補償電流の値を制御する。【選択図】図１