variable frequency speed control造句

1997 started to produce variable frequency speed control system for cargo lift
?1995年被省政府确认为先进技术企业
the strategy of direct torque control is one of the variable frequency speed control scheme, which was developed in 1985 by prof . depenbrock and which was one of high performance control of induction motor drives after vector control
1985年德国学者depenbrock提出了异步电动机的直接转矩控制(directtorquecontrol)变频调速思想，dtc是继矢量控制之后发展起来的一种高性能交流调速技术。
It's difficult to find variable frequency speed control in a sentence. 用variable frequency speed control造句挺难的