PLL-Based Resonance of a Type-4 Wind Generator in a Series-Compensated Transmission Line

Currently, electric power systems have been integrating massive amounts of renewable energy sources based on power electronics converters. This tendency has provoked new stability issues because of the interactions of controls in power electronics with passive elements in the power system. As a result, new oscillation issues have been reported, such as resonance problems in wind turbine generators with series compensation. This paper evaluates resonance problems in a wind turbine generator type 4 using the impedance-based stability criterion to study phase-locked loop control interactions. The sensitivity due to the bandwidth of the phase-locked loop is assessed using small-signal models, and nonlinear time-domain simulations in Matlab/Simulink are conducted to support the results.