Browsing by Author "Restrepo, Mauricio"
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Item Modeling and Testing of a Bidirectional Smart Charger for Distribution System EV Integration(Institute of Electrical and Electronics Engineers (IEEE), 2016-03-25) Restrepo, Mauricio; Morris, Jordan; Kazerani, Mehrdad; Canizares, Claudio A.This paper proposes a model of a single-phase bidirectional electric vehicle (EV) charger with capability of operating in all four quadrants of the P-Q plane. The steady-state and step responses of the proposed model are used to validate it based on the actual responses of a bidirectional charger prototype for different P-Q requests. The model can be used efficiently in time-domain simulations that require models of a number of EV chargers, such as EV integration studies in low-voltage (LV) distribution networks. A practical case study is presented to demonstrate and test the proposed smart charger and model, investigating the provision of vehicle-to-grid (V2G) for active and reactive power in an LV residential distribution network. These results demonstrate the advantages of the presented charger model for developing V2G strategies in distribution networks.Item Optimization- and Rule-based Energy Management Systems at the Canadian Renewable Energy Laboratory microgrid facility(Elsevier, 2021-03-05) Restrepo, Mauricio; Cañizares, Claudio A.; Simpson-Porco, John W.; Su, Peter; Taruc, JohnThis paper presents the development, implementation, and commissioning of two different Energy Management Systems (EMSs) for the Canadian Renewable Energy Laboratory (CANREL), a microgrid testbed located in Guelph, ON, Canada, for the existing hardware, software, and communication infrastructure, which constrained the implementation options. A Rule-based EMS (RBEMS), which is typically found in microgrid controllers nowadays, and an implementation of an Optimization-based EMS (OBEMS), which is not usual in today’s controllers, are proposed, tested, and demonstrated in the microgrid testbed. The RBEMS consists of a state machine that represents the commitment of different genset units in the system and the curtailment of load and renewable generation. The OBEMS is based on a unit commitment model for microgrids that minimizes the generation and curtailment costs, while operating the microgrid equipment according to technical limits. Both EMS systems are integrated into a Python application which integrates various open-source packages and solvers, making it affordable, flexible and easy to replicate and upgrade. The successful implementation and performance of the EMS is discussed, showing that the components of the microgrid follow the dispatch commands, with the OBEMS yielding better overall results than the RBEMS, as expected, using the existing communications links and maintaining the stability of the microgrid.Item Smart Operation of Electric Vehicles With Four-Quadrant Chargers Considering Uncertainties(Institute of Electrical and Electronics Engineers (IEEE), 2018-03-15) Mehboob, Nafeesa; Restrepo, Mauricio; Canizares, Claudio A.; Rosenberg, Catherine; Kazerani, MehrdadGiven the expected impact of electric vehicle (EV) charging on power grids, this paper presents a novel two-step approach for the smart operation of EVs with four-quadrant chargers in a primary distribution feeder, accounting for the uncertainties associated with EVs, and considering the perspectives of both the utility and the EV owners. In the first step of the proposed approach, the mean daily feeder peak demand and corresponding hourly feeder control schedules, such as taps and switched capacitor setpoints, considering the bidirectional active and reactive power transactions between EVs and the grid, are determined. A nonparametric bootstrap technique is used, in conjunction with a genetic algorithm-based optimization model, to account for EV uncertainties and discrete variables. In the second step, the maximum possible power that can be given to connected EVs at each node, while providing active and/or reactive power to maintain the peak demand value and corresponding feeder dispatch schedules defined in the first step, is computed every few minutes in a way which is fair to the EVs. The proposed approach is validated using the distribution feeder model of a real primary feeder in Ontario, Canada, considering significant EV penetration levels. The results show that the proposed approach could be implemented in practice to properly operate EVs, satisfying feeder, and peak demand constraints, which would be better than the business-as-usual practice or a popular heuristic method in terms of number of tap operations, system peak demand, and voltage regulation.Item Three-Stage Distribution Feeder Control Considering Four-Quadrant EV Chargers(Institute of Electrical and Electronics Engineers (IEEE), 2016-12-15) Restrepo, Mauricio; Canizares, Claudio A.; Kazerani, MehrdadWith the increased penetration of electric vehicle (EV) chargers in distribution systems, there is a need to understand and minimize their impact on medium-voltage (MV) and low-voltage (LV) networks. Thus, this paper proposes a three-stage algorithm to coordinate the operation of four-quadrant EV chargers with other volt/var control devices in MV and LV distribution feeders. The first stage operates on a day-ahead basis and defines the load tap changer and capacitor schedules while minimizing the peak load associated with EVs in the distribution system. The second and third stages update their operation every five minutes, to fairly allocate the aggregated and individual EV loads in the MV an LV feeders, respectively, while minimizing active power losses and voltage deviations. The proposed technique is applied to CIGRE's North-American MV and LV benchmark systems to demonstrate its ability to properly allocate EV loads, and improve distribution system performance in terms of losses and voltage deviations.