Impact of Communication Delays on Voltage Control Accuracy and Stability of a PV Park

Photovoltaic parks often utilize communication among the different converters to ensure accurate PCC voltage control and disturbance rejection. However, time delays in the communication network can affect the control performance and stability, and need to be analyzed to design a proper converter-level and system-level control system. In this paper, the communication delay impact on the voltage restoration performance of multiple grid-following converters in a PV park, coordinated by Secondary Voltage Control (SecVC) during fast grid transients, is investigated. The steady-state and dynamic performance are studied under a variety of grid conditions, control parameters, and local PCC voltage estimates. Finally, time-domain simulations with constant and stochastic time delays are provided to confirm the analytical results.