Seamless Integration of Renewable Generation and Plug-in Electric Vehicles into the Electrical Grid.

Demand-side Control;Hysteresis-based Loads;Plug-in Electric Vehicle Charging;Distributed Control;Photo-voltaic Inverters;Electrical Engineering;Engineering;Electrical Engineering: Systems

Kundu, SoumyaGrizzle, Jessy W. ;

University of Michigan

关键词: Demand-side Control;    Hysteresis-based Loads;    Plug-in Electric Vehicle Charging;    Distributed Control;    Photo-voltaic Inverters;    Electrical Engineering;    Engineering;    Electrical Engineering: Systems;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/99858/soumyak_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

An imminent release of plug-in electric vehicles en masse will add substantial load to electrical power grids that are already operating near limits. Coordinated control of vehicle charging, however, can eliminate the need for expensive overhauls of grid infrastructure. Furthermore, the growing penetration of renewable energy sources provides an excellent opportunity to meet the increased electricity demand, but the challenge remains to tackle the variability and intermittency associated with renewable energy.Our research focuses on identifying and analyzing key issues regarding interactions between renewable generation, vehicle charging, and the power grid. In order to address these issues, we are designing control schemes that ensure seamless integration of newer forms of generation and load, while achieving satisfactory grid-level performance in areas such as loss minimization, voltage regulation, generation balancing and valley filling. Feedback control oriented analytical models have been developed to regulate aggregate demand by certain time deferrable loads (thermostatic loads, plug-in electric vehicle chargers). It is shown that, via a hysteresis-based pulse-width modulated type control, a linearized system response model can be established from the evolution of probability distribution of states (thermostat temperature, battery state-of-charge) of loads. It is shown that grid-level objectives, such as generation tracking and valley filling, can be satisfied by using only the aggregate power as measurement. A framework is presented to study the impact of synchronization in plug-in electric vehicle chargers on the voltage resiliency of electrical grid. It is shown that a fault-induced synchronized tripping of chargers can cause critical over-voltage situations in a distribution feeder. A non-linear state-space model is developed that can truly capture the complex, easily synchronizable, dynamics of hysteresis-based loads. It is reported that, under certain control input signals, such load aggregation can display instability in the form of period-adding cascade. A control method is proposed that optimally allocates photo-voltaic inverter output in a de-centralized way to minimize line losses and voltage deviations. While optimality of this de-centralized control law is proved under certain assumptions, its validity in a more practical scenario is also discussed and possible modifications are suggested.