thanks for the reply sir,
i have changed the smoothing capacitor and pulse generator pulses values so many times the over shoot is repeating,if i am increasing the sample time of the model the peak over shoot is gone but what is relation between peak over shoot and sample time.
The overshoot is a result of the resonance of the inductor and the output capacitor.
You can reduce that during startup by starting with a very low pulse duty-cycle and then slowing increasing it.
In a real boost converter there is a feedback loop with compensation from the output to the PWM generator, to cancel the effects of the output LC resonance.