International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 02 | Feb -2017
p-ISSN: 2395-0072
www.irjet.net
IMPACT OF DYNAMIC DEMAND RESPONSE IN THE LOAD FREQUENCY CONTROL P CHANDRASEKHARA1, B PARASURAM2, C VISWANATH3, A SURESHBABU4 PG Scholar, Dept. of EEE, B.I.T Institute of Technology,Hindupur Affiliated to JNTUA, A.P, India Associate Professor in Dept. of EEE, , B.I.T Institute of Technology,Hindupur Affiliated to JNTUA, A.P, India 3 Associate Professor in Dept. of EEE, , B.I.T Institute of Technology,Hindupur Affiliated to JNTUA, A.P, India 4 Lecturer in Dept. of EEE, ,Mizan-Tepi University,Tepi,Ethiopia 1
2
---------------------------------------------------------------------------***-------------------------------------------------------------------------Abstract:- Demand Response (DR) has proved to be an inevitable part of the future Power-grid. Most research works have been documented in the literature on the benefits and implementation of DR. However, some works have been reported on the impacts of DR on dynamic performance of power systems, specifically on the load frequency control (LFC) problem. This paper makes an attempt to fill this gap by introducing a DR control loop in the traditional LFC model (called LFC -DR) for a singlearea power system. The model has the feature of optimal operation through optimal power sharing between DR and supplementary control. The effect of DR communication delay in the controller design is also considered. It is shown that the addition of the DR control loop increases the stability margin of the system and DR effectively improves the system dynamic performance. Simulation studies are carried out for single area power systems to verify the effectiveness of the proposed method. Index Terms—Demand response (DR), linear quadratic regulator (LQR), sensitivity, single-area power system model, smart grid, stability, steadystate error.
with two-way communication. It is well known that DR increases system reliability and flexibility to manage the variability and uncertainty of some RE resources, decreases the cost of operation, and enhances system efficiency. Furthermore, DR can be used to provide ancillary services (AS) for regulation reserve and to respond momentarily to the area control error (ACE). A number of studies have also addressed the effectiveness of decentralized dynamic demand control on stabilization of grid frequency, mainly at the transmission level. However, the above studies present the following shortcomings: They do not present a general framework for the analysis of the impacts of DR on a general power system model and load. AGC model has not been considered in the analysis. Only specific loads (such as HVAC, EWHs and lighting) have been considered in and specific power systems without generalization. Communication delay in central DR, and measurement delay in decentralized DR have not been considered. Frequency regulation as AS have not been studied. Only under-frequency load shedding (UFLS) characterization has been analysed. Unreal assumptions for the availability of DR at all times have been made. Load-damping coefficient, which can improve frequency stabilization, has been ignored. Only sensitivity analysis of frequency-related load-damping coefficient characteristic without generalization and DR control is presented. In the last ten decades, traditional LFC models have been revised and modified to include the different types of power plants, including RE power generation with actual limitations, such as ramp-up/down limits, in the traditional and deregulated power market. These models are useful in small disturbance studies such as small variations in load and generation, and in controller design. However, so far in the literature, the extreme shedding of the responsive loads in emergency DR could lead to unexpected power oscillations, which complicate the
I. INTRODUCTION Traditionally, frequency regulation in power system is achieved by balancing generation and demand through load following, i.e., spinning and non-spinning reserves. The future power grid is foreseen to have high penetration of renewable energy (RE) power generation, which can be highly variable. In such cases, energy storage and responsive loads show great promise for balancing generation and demand, as they will help to avoid the use of the traditional generation following schemes, which can be costly and/or environmentally unfriendly. Given the limited availability, low efficiency, and high cost of large storage devices, real time smart responsive load participation, known as demand response (DR), has been actively considered for power balancing. It can be achieved by active consumer participation in realtime to maintain balance between generation and demand
© 2017, IRJET
|
Impact Factor value: 5.181
|
ISO 9001:2008 Certified Journal
| Page 262