A power converter system is provided, comprising a plant having a plant input and a plant output; and a plant identification filter that receives the plant input and the plant output, and estimates the values of poles and zeros of the plant, wherein the plant identification filter updates the estimates of the poles and zeros, based upon the plant input and the plant output, beginning from an initial state; and a rate at which the plant identification filter updates the estimates of the values of the poles and zeros is slower than a rate at which the plant input and the plant output are received by the plant identification filter.