by Fangxing Li
The interest in managing electricity demand surfaced in earnest during the 1970s as economic, political, social, technological, and resource supply factors combined to change the electricity sectors’ operating environment and its outlook for the future. Ever since then there have been staggering capital requirements for new plants, significant fluctuations in demand and energy growth rates, declining financial performance of electric utilities, power producers and energy service providers, and regulatory and consumer concern about rising prices. A successive series of concepts have evolved as an effective way of mitigating these risks including: Demand – Side Management (DSM), Demand Response (DR), and Transactive Energy.
In January 2017, the Journal of Modern Power Systems and Clean Energy ( MPCE) has successfully published a Special Section on “Managing Electricity Demand”. While more than 80 full papers were submitted, only 10 papers were selected for final publication in MPCE. Below are some key findings and conclusions of a few representative sample papers which documented the latest technologies in demand-side management, demand response and transactive energy in the smart grid paradigm.
In the paper entitled “The Evolving Practice of Demand-Side Management”, the evolution of demand-side management is reviewed. Then, the technologies, programs and activities of demand-side management are described with U.S. data as examples. Finally, the future evolution path of DSM is discussed based on the background of smart grid.
In the paper entitled “From Demand Response to Transactive Energy: State-of-the-Art”, the state of the art in the research and industrial practice in demand response is reviewed. In particular, the design of demand response programs, performance of pilot projects and programs, consumer behaviors, and barriers are discussed. Also discussed include characteristics, the state of the art, schemes, promises and challenges of transactive energy, which is a variant and generalized form of demand response in that it manages both the supply and demand sides.
In the paper entitled “Demand Response for the Frequency Control of a Multi-area Power System,” the authors propose a frequency control strategy using demand response for a multi-area power system. The tie-line power flow is utilized as an additional input signal for demand response control. Then, the frequency regulation is formulated as a multi-objective optimization problem to obtain the optimal control parameters. Numerical results on a three-area system verify the proposed method.
In the paper entitled “Controllability and stability of primary frequency control from thermostatic loads with delays,” the authors study the impact from response delays and lockout constraints on the controllability of aggregated refrigerators, i.e., thermostatic loads, when they offer primary frequency control (PFC). A framework to systematically address frequency measurement and response delays is proposed. Extensive simulation studies are conducted to investigate the effects of measurement delay, ramping times, lockout durations and rotational inertia on the controllability of the aggregation and system stability.
In the paper entitled “Green neighbourhoods in low voltage networks: measuring impact of electric vehicles and photovoltaics on load profiles,” a United Kingdom (UK) experience in low-carbon technology (LCT) is discussed. In this paper, the authors proposed an agent based model that estimates the growth of LCTs within local neighbourhoods, where social influence is imposed. Real-life data from a low-voltage network is used that comprises of many socially diverse neighbourhoods. Then, a probabilistic approach is described to determine lower and upper bounds for the model response at every neighbourhood. Finally, the authors discuss the potential application of these bounds in future network planning.
Fangxing Li, Prof
Department of EECS
The University of Tennessee, Knoxville, USA