摘要
本文介绍一种实用的串级调速线路——内反馈串级调速，它省去了逆变变压器，占地面积少，谐波小，逆变器采用强迫关断换流环节，产生超前无功送回电源，提高了系统的功率因数，转子用可控整流电路，它可以减少死区，控制逆变故障电流，采用补脉冲，有效地防止了逆变颠覆，提高了系统的可靠性。这些措施克服了原串级调速的很多缺点，如功率因数低、谐波大、死区大、占地多等，当然亦可根据实际情况采用不同线路，使系统简化，满足使用要求。
A practical serial SR circuit-internal feedback serial SR-is described.The invertertransfarmer is omitted,the floor area is small,and is with lower harmonics,Forced commutation is used forthe inverter,and can yield leading idling current which is transmitted back to the power source to increasethe power factor. A controllable rectifier circuit is employed for the rotor to reduce the dead-band and tocontrol the fault current of the inverter. Additional pulses are utilized to prevent the inverter from failureefficiently,making the system more reliable. All the measures mentioned ahi1ve can overcome manyshortcomings of the traditional serial SR system,such as low power factor,wide dead-band and large floorarea. For more specific applications,different circuits Tnay be employed to simplify the system.
