The paper analyzes the configuration, design and operation of multi-MW grid connected solar PV systems with practical test cases provided by a 10MW field development. In order to improve the capacity factor, the PV system operates at its maximum power point during periods of lower irradiance, and the power output is limited to a rated value at high irradiance. The proposed configuration also incorporates a utility scale battery energy storage system (BESS) connected to the grid through an independent inverter and benefits of the experience gained with a 1MW 2MWh BESS large demonstrator. The BESS power smoothing and frequency regulation capabilities are illustrated though combined theoretical and experimental studies. The behavior of the grid connected PV and BESS combined system is studied using a modified IEEE 14-bus test system implemented in PSCAD T M /EMTDC T M. The paper also includes a sizing exercise for energy storage in order to provide dispatchable PV power.

The large scale deployment of Electric Vehicle (EV) charging infrastructure can result in high added utility costs due to the peak demand cost structure in utility bills for commercial and industrial users. A method to minimize this disincentive to EV adoption is proposed that relies on forecasting demand so that EV charging activity can be intelligently controlled. This study examines multiple forecasting models and techniques to determine the optimal algorithm for use in the proposed control system. Simulation results are presented for each of the forecasting algorithms with the best mean absolute percent error of 1.26% using a neural network with averaging. This results in a reduction in the peak demand electric costs of approximately 95%.

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Typically, solar inverters curtail or "clip" the available power from the PV system when it exceeds the maximum ac capacity. This paper discusses a battery system connected to the dc-link of an inverter to recuperate this PV energy. Contrary to conventional approaches, which employ two dc-dc converters, one each for the battery and solar PV system, the proposed configuration utilizes a single dc-dc converter capable of simultaneously operating as a charge controller and a maximum power point tracking (MPPT) tracking device. In addition to improving the overall system capacity factor, increasing the conversion efficiencies and ensuring MPPT stability, the proposed configuration offers a simple solution for adding energy storage to existing PV installations. With this configuration, the excess power that will otherwise be curtailed due to inverter rating limitations is stored in the battery and supplied to the grid during periods of reduced irradiance. Moreover, a systematic methodology for sizing a dc-bus connected battery to minimize total PV energy curtailed was developed using an annual PV generation profile at the Louisville Gas and Electric and Kentucky Utilities (LG&E and KU) E.W. Brown solar facility at Kentucky. The detailed behavior of the proposed system and its power electronics controls and operations were validated with case studies developed in PSCAD T M /EMTDC T M for variable power generation and PV output power smoothing.