AC and DC短语⁹⁶⁶⁷⁷⁺⁶ 基本例句 交流和直流 The problem of oversimplification and improper selection of DC model, which exists in the DC modeling when AC and DC systems interact in AC/ DC hybrid power system, is discussed. 讨论了目前研究交、直流混合电网交直流系统相互作用时在直流建模上存在的模型过度简化及模型选用不恰当的问题； cnki