Disturbance Signal Input Method for Excitation System Modeling and Identification Test
Daguang Wang · 2007
Power system modeling and parameter identification are brought into effect by most Province Power Grid Companies in China.Pseudo random binary-code signal(PRBS) and step-up signal have been widely used for modeling and parameter identification test of synchronous generator excitation system,but for some excitation system,there is no input port to import the test signals.The paper proposes a resistance-based signal coupling(RBSC) method.By using the PRBS method,step-up signals can be coupled into the feedback input signal of excitation systems.The principle of the RBSC method is described detailed firstly,then the method has been used in two practical synchronous generators,one is of hydraulic turbine and the other of steam turbine,for excitation system modeling and identification test.It is shown that both the PRBS and the step-up signals can be coupled into the terminal voltage feedback input signal easily.Both the frequency-domain and time-domain identification methods can be implemented for excitation system model parameters identification.The precision of the identified models have been verified by comparing the responses between the digital simulation using the models and the field test for the same system at the same disturbance input.The proposed RBSC method has been successfully applied in Fujian Province Power Grid Companies in China for excitation system modeling and parameter identification.