Steady state control limitations in the drive system with the self-commutated synchronous motor

In the paper limitations in the drive system with the high power self-commutated synchronous motor operating in the steady state are discussed. Three limitations: commutation reserve for machine inverter, voltage (control) reserve for network rectifier and thermal limitation for motor are taken into consideration. Firstly the structure of the drive and requirements related to its control are given and then the separate limitations are explained. The influence of the limitation on the drive characteristics and losses in the system are presented. The need of compromised control strategy for the drive is shown as the requirements of high efficiency of the drive and its reliability are opposed. The paper presents how to solve the problem in the composed system of the electrical drive of high power.