An analog fuzzy logic controller for power converters

A fuzzy-logic controller that implements an optimal algorithm as a control law is proposed as an alternative to control power converters. The algorithm tries to minimize a given cost function by means of exhaustive system simulation. The result is a nonlinear optimal control surface. A silicon implementation of a fuzzy-logic controller which uses a current-mode circuit for the input membership functions, and pulse stream arithmetic in the inference process, has been used to implement the control-strategy. A PWM DC/DC power converter is used as a test system. Experimental results show a large improvement in the transient response, confirming the validity of the proposed approach.