Virtual Impedance based Lyapunov Controller for DC-DC Converter-fed Constant Power Load

This paper demonstrates the design and analysis of a novel Virtual Impedance based Lyapunov Controller for DC-DC boost converter fed Permanent Magnet Direct Current (PMDC) drive. The motor drive acts as Constant Power Load (CPL) destabilizing the system in open loop condition. The non-minimum phase nature of boost converter restricts the use of conventional Voltage Mode Control (VMC) method due to slowed dynamics. Two Loop Control provides an active damping to stabilize the system in closed loop. On the other hand, the Virtual Impedance (VI) Control provides active damping to the system in a more effective way with advantages of wide duty-ratio operation, improved transient performance and efficiency. In case of Lyapunov Controller (LC), an improved supply and load disturbance rejection is achieved. The proposed controller offers excellent dynamics and control of dc-link voltage and speed of motor. It also offers way better transient performance and is insensitive to large-signal perturbations. The comparison for conventional Two Loop Control, Virtual Impedance Control, Lyapunov Controller and the proposed controller has been carried out. The theoretical analysis is validated by simulation results.