Stability and accuracy considerations in the design and implementation of wind turbine power hardware in the loop platform

Abstract

There is increasing interest in the evaluation of wind turbine control capabilities for providing grid support. Power hardware in the loop (PHIL) simulation is an advanced method that can be used for studying the interaction of hardware with the power network, as the scaled-down actual wind turbine is connected with a simulated system through an amplifier. Special consideration must be made in the design of the PHIL platform to ensure that the system is stable and yields accurate results. This paper presents a method for stabilizing the PHIL interface and improving the accuracy of PHIL simulation in a real-time application. The method factors in both the power and voltage scaling level, and a phase compensation scheme. It uses the reactive power control capability of the wind turbine inverter to eliminate the phase shift imposed by the feedback current filter. This is accomplished with no negative impact on the dynamic behavior of the wind turbine. The PHIL simulation results demonstrate the effectiveness of the proposed stability analysis method and phase compensation scheme. The strength of the platform is demonstrated by extending the simulation method to wind turbine control validation.