Distribution System State Estimation Using PV Separation Strategy in LV Feeders With High Levels of Unmonitored PV Generation

Abstract

Distribution system state estimation (DSSE) is a critical analysis tool for active distribution networks (DNs). Unlike weighted least squares techniques, which are static DSSE methods, the augmented complex Kalman filter (ACKF) is a novel technique that considers the system's dynamic behavior. Currently, most DNs integrate a large number of unmonitored residential photovoltaic (PV) generations. Existing unmeasured PV sources violate the white noise assumption in Kalman and least-squaresbased estimators, causing the estimator to be biased. Because the one-step difference of aggregated customer demand is characterized as white noise, the suggested PV estimation technique based on the differencing strategy is used to decouple PV from the measured load. Using the specified contribution factors, the new online pseudo current injections are generated. In addition, the estimator's accuracy is improved by using a new PV-scalingaided ACKF approach based on the PV separation strategy. For validation purposes, this method is applied to real DN case studies. This study also makes use of an actual dataset to illustrate the efficacy of the proposed technique. The proposed technique outperforms the existing snapshot and dynamic DSSE techniques, and significant improvements are achieved in terms of accuracy and computational cost.

Intensive Data-Driven Model for Real-Time Observability in Low-Voltage Radial DSO Grids

“…Comparing the computation times to other DSSE methods found in the literature, the proposed method performs well when considering the computation time of 0.79 h as in [28], and its result is similar to the computation time in [27] of 1 s. Furthermore, these computation times should be compared in the context of the prediction results. For instance, in [27], a mean average error of 0.3% was achieved, corresponding to 0.003 per unit (p.u. ), and an RMSE of 0.59 V is reported in [25].…”

“…However, the method relies on the load estimations of customers and the number of customers to produce a generic feeder and is rather designed for voltage control in networks with on-load-tapchangers, limiting the applicability in the context of this study. Mokaribolhassan et al [27] developed a DSSE method using the augmented complex Kalman filter, also in a power system with PV systems. However, the authors here apply a technique where they separate the PV generation from the customer loads.…”

A Stability Quantitative Analysis Method of Three-Phase Four-Wire Grid-Connected Systems Considering Frequency Coupling and Sequence Components Coupling

“…Driven by falling prices and improvements in technology, the installation of rooftop solar photovoltaics on distribution grids has increased dramatically in recent years. And the configuration shown in Figure 1 become a common scenario [3], [4], [5], [6], [7], [8] in which single-phase rooftop photovoltaic inverters (SI) are divided into three phase group and connected to the three-phase four-wire distribution grid in star (Y) configuration. Concurrently, three-phase four-wire…”