Filtering modified sine wave inverters

Need help in improving performance and generally improving the 220 V AC voltage from a Mosfet based pwm inverter . .. .

Need ideas for a simple line filter sort of circuit that would help suppress voltage spikes and surges.. any ideas are welcome..

PS , the idea has to be practical

Hello,

Take a look at this page:
http://myweb.tiscali.co.uk/nuukspot/decdun/mainsconditioner.html

Greetings,
Bertus

would putting a simple cap rated X work ... and a series resistor to control the current flowing through it.. ?

i built a pwm inverter and i use a 1.5MF 400V capacitor in parallel with the output. without the capacitor fan makes noise and has less speed.