Estimation of the Plant Controller Communication Time-Delay Considering PMSG-Based Wind Turbines

TL;DR

This work tackles the problem of estimating the communication time-delay between wind turbine inverters and the plant controller, which can destabilize grids under large delays. It presents a UKF-based dynamic state estimation approach on a reduced PMSG-WT model, utilizing PMU data to estimate the plant-control signal $\hat{q}_{plant}$ and its delay relative to a delay-free plant model via cross-covariance with $q^{pre}_{plant}$. The method demonstrates accurate delay identification across multiple fault and disturbance scenarios on the IEEE 39-bus system, with robustness depending on signal strength (TVE) and delay magnitude, offering an online tool for transmission system operators to adjust plant models in dynamic studies. The approach is extensible to other renewables and remains applicable even when the oscillatory content is present, though observability challenges at certain configurations warrant further study.

Abstract

The communication control delay between the inverters and the power plant controller can be caused by several factors related to the communication link between them. Under undesirable conditions, high delay values can produce oscillations in the wind power plant that can affect the rest of the power system. In this work, we present a new robust methodology for wind turbines to estimate the value of the communication control delay using PMU data. Several scenarios are considered where external faults are simulated and the performance of the algorithm is evaluated based on dynamic state estimation of the mathematical model of the wind turbine. In this paper, we have shown that the characterization of the delay can be performed offering the transmission system operator an online tool to identify the most suited communication delay for the plant controller models used in dynamic studies.

Figures (7)

• Figure 1: Block diagram of the proposed methodology.
• Figure 2: Schematic diagram of a PMSG-based WT. .
• Figure 3: Block diagram of the pitch controller.
• Figure 4: Block diagram of the plant controller.
• Figure 5: IEEE 39 bus system.