Design and implementation of type-III controller in tri state boost converter

DC-DC power supplies are used in almost every sphere of engineering like PC/laptop, chargers, spacecraft, HVDC transmission etc. A steady source of voltage is required irrespective of any changes in line, load condition & parametric uncertainties for their application. The steady state behaviour of converter can be explained by the topology of converter and the controller has taken an important role for maintaining the accurate transient, i.e. dynamic performance. DC-DC power supplies like boost has a dynamically shifting right- half plane (RHP) zero in the converters small signal control to output transfer function operating in continuous conduction mode. So it is difficult for the PID controller to exhibit good performance. For this reason a special kind of controller, i.e. Type III controller is introduced for obtaining better performance. The extra degree of freedom introduced in the Tri - state boost converter using a freewheeling interval. The non-appearance of RHP zero allows the control process to achieve larger bandwidth under the closed loop condition resulting fast response. Results are compared with classical boost converter using Type III controller in both analytical, simulation (Matlab/Simulink) method. The results clearly represent the better dynamic performance of tri state boost converter. It can be used in application wherever fast response boost action is required.