A field forcing method for reduction of characterization time when testing synchronous machines

A new field forcing method based on the use of a PID controller in the exciting circuit of the tested synchronous machine and a method for determination of the controller’s optimal parameters are proposed. The optimal parameters of the controller are determined by the gradient descent method implemented in the Simulink Design Optimization block. Simulation in the MATLAB + Simulink visual object-oriented programming environment shows that the hardware-and-software implementation of the method for automated acquisition of the static characteristics, i.e., the no-load curve, the short-circuit curve, and the V-curve, of a particular 800-kW synchronous machine enables a reduction in the duration of these operation by by from three to five times. The time constants of the tested machines grow with their increasing capacities. Consequently, the higher the capacity of a synchronous machine, the greater the reduction in the time required to acquire the static characteristics. Thus, the proposed field forcing method as applied to hardware-and-software complexes of stands for testing synchronous machines in the electric machine industry will enable a considerable reduction in the time of the test procedure, which ultimately will result in reduced financial costs.