Application of packet control method for a high power high voltage flyback converter to reduce noise influence

In the regulated switching power supplies, the output voltage is usually sampled across a resistive voltage divider. In high voltage applications, the resistance of the voltage divider is very high in order to reduce its power loss. Therefore, these resistors are very good receivers of environment noise. This paper introduces a new control method for a high power, high voltage flyback converter insensitive to the noise caused by ringing due to the leakage reactance of a high voltage flyback converter. In this method, output voltage is sampled in an intentionally extended cycle to be sure that all the oscillations are damped. Therefore there is no need to additional damping circuits and snubbers network and the efficiency of converter is not reduced. This method is applicable to any flyback converter in discontinues conduction mode. Mathematical concept is introduced and simulation and experimental results are presented