A new method of compensation using pole-zero cancellation applied to the design of a voltage-controlled buck converter

Three design methods for compensation of a voltage-control buck converter are (1) a single dominant pole; (2) two real zeros, two real poles; and (3) two complex zeros and two real poles. The paper will give the design procedure and equations for the three circuits , allowing designers to pick the Q of the system, the bandwidth, and the dc gain. The comparison was made for an amplifier gain of 100. The filter elements and the load were the same in all cases. Dynamic damping was used to give a filter Q of 0.707 to optimize the transient response to dynamic load changes. The frequency response was 350 Hz for the dominant-pole case for an optimized flat response, and 1000 Hz with an approximate flat response for the other two cases. Because all systems had an approximately flat response, the expected differences were seen in the rise time caused by frequency-response differences and, particularly , in the sensitivity of the response to changes in the values of the filter inductance, capacitance, and load resistance. Sensitivities were determined for each element.