So , this paper researches the principle of measuring system of insulating oil dielectric loss and volume resistivity . during the measuring process , the insulating oil must be heated and kept at 90 in 15 minutes . medium - frequency induction heating method is presented to instead of the electrical resistance furnace heating method on chapter 2 , and a kind of subdivision - controlled integral - separated digital pid algorithm is designed to control the medium - frequency induction heating apparatus 本文對恒溫控制系統(tǒng)進行了研究,提出了以中頻感應加熱方式取代原有的電阻爐加熱方式,設計了一種分段控制的積分分離式數(shù)字pid控制器來控制中頻感應加熱裝置,并通過通信設計將恒溫控制系統(tǒng)與介損及體積電阻率測試系統(tǒng)有機結(jié)合為一體機,實驗結(jié)果表明該恒溫控制系統(tǒng)完全滿足介損及體積電阻率測試中的控溫要求。