Abstract
This paper proposes the digital excitation control system based on the H∞ control for an engine generator. After the mathematical model for control design is derived from the equivalent circuit of a generator, the problem is formulated as the mixed sensitivity problem. Modeling errors and measurement noise to design weight functions are identified by step response experiments both without load and with maximum rate load. The effectiveness of proposed method is verified by both some numerical simulations and experiments using 4-poles 5kVA engine generator. As a result the proposed system represents robust control performance compared with the classical PID controller designed Ziegler-Nichols's method. Since the obtained H∞ controller becomes high dimensional system, it usually takes much calculation time. From the view point of practical implementation to realize fast calculation, the digital AVR based on DSP (Digital Signal Processor) is used. Implementing the controller, the digital PWM pulse generation arlgorithm is applied.
