Self-optimizing Control Strategy of Conduction Angle for Doubly Salient Electromagnetic Generator to Minimize Excitation Current

Compared with the uncontrolled rectifier, the controlled rectifier with angular position control (APC) can improve the output capacity of the doubly salient electromagnetic generator (DSEG) effectively. By adjusting the conduction angle in APC strategy, the excitation current can be minimized to avoid being too large at low speed, broadening the operating range of the DSEG and minimizing excitation loss. For the relation between the conduction angle and the excitation current is nonlinear and changes with the working conditions, the conduction angle corresponding to minimum excitation current is usually given by the lookup table or the fit function which requires massive work and is low in generality. To solve this problem, this paper proposes a self-optimizing control strategy for the conduction angle, according to the characteristic of the relation between the excitation current and the conduction angle. This strategy which based on the perturbation and observation method is convenient and has high generality. By adding perturbation to the system to change the conduction angle, the minimum excitation current is tracked online. Finally, the effectiveness of the strategy is verified by simulations under different working conditions.