There are some previous works about filter design for AC to DC converter

There are some previous works about filter design for AC to DC converter. Previous work about the filter design for AC to DC converter are done by S. Pyakuryal and M. Matin 11. AC power is available commercially at low cost. DC power is more expensive to produce and therefore a method of changing ac to dc is needed as an inexpensive dc source. AC power can be converted to DC power by using a rectifier. When ac power is converted to dc power using rectifiers, dc output contains undesirable ac components that called a ripple. Many rectifier applications require that the ripple do not exceed a specified value. If the ripple exceeds the specified value, different unwanted effects appear in the system. Some of the unwanted effects are stray heating and audible noise. However the ripple can be mitigated using an output filter. When a capacitor is used alone or an inductor is used alone as a filter, there is mathematical expression available for calculating the values of capacitor or inductor for controlling the ripple under the specified value, but when both capacitor and inductor are used together, there is no mathematical formula available to calculate the values.