POWER CONVERTER, CONTROL METHOD FOR POWER CONVERTER, DC POWER TRANSMISSION SYSTEM, FREQUENCY CONVERTER, AND REACTIVE POWER COMPENSATOR

• Main Authors: KIYOFUJI YASUHIRO, ICHINOSE MASAYA, INOUE SHIGENORI, KATO SHUJI, NARUSHIMA JUN, OGURA MAKOTO, EGUCHI YOSHIO
• Format: Patent
• Language: English; Japanese
• Published: 02.07.2015
• 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

PROBLEM TO BE SOLVED: To solve the problems that a power converter required to continuously operate is not provided with an opportunity to calibrate a current detection system so that an offset error of the current detection system increases according to secular change in a current sensor, an amplification circuit, an A-D converter, and the like, which may generate excessive DC biased magnetization in a transformer as described above.SOLUTION: There is provided the power converter, which is connected to a transformer or a reactor, comprises at least two signal processing means to be connected to a current sensor that detects currents of the transformer or the reactor, where a switcher is provided at an input portion of the signal processing means and the switcher has function of making input of at least one signal processing means approximately zero. 【課題】連続運転を要求される電力変換装置においては，電流検出系を校正する機会が得られない。そのため，電流センサ，増幅回路，Ａ−Ｄ変換器段などの経年変化にしたがって，電流検出系のオフセット誤差が増大し，前述のような変圧器の過大な直流偏磁に至る可能性があった。【解決手段】本発明は，変圧器またはリアクトルと接続する電力変換装置において，前記変圧器またはリアクトルの電流を検出する電流センサに接続される少なくとも２つの信号処理手段を備え，前記信号処理手段の入力部に切替器を設け，前記切替器は少なくとも１つの信号処理手段の入力を概ね零とする機能を有することを特徴とする電力変換装置を提供する。【選択図】 図１