Nonlinear control characteristic research of self-oscillating electronic ballast

In this paper, the self-oscillating LC series resonant parallel load inverter for electronic ballast applications is investigated from a system point of view. By considering the discharge lamp as a resistor in steady state, the self-oscillating series resonant parallel load inverter with lamp loads can be naturally modeled as a relay system. Precise frequency determination and stability of self-oscillating is analyzed using the methods by describing function method, Tsypkin method (frequency domain) and Hamel method (time domain). The characteristic of these three kind methods is analyzed respectively. The design approach is described and implemented successfully in a 36 W fluorescent lamp system.