Load demand management with high renewable energy penetration in distribution systems

分布式可再生资源（DRRs）与传统和化石燃料资源有着根本的区别。它们的来源（尤其是风速和太阳辐射）是无法控制或储存的。此外，可再生能源发电由于其高间歇性，往往与消费者负荷需求实时不相关。它可能是导致电力系统不稳定的主要原因之一。考虑到这些drr在未来电网中的渗透率增加（50-60%），即使是传统发电厂也难以有效参与，对维持电网的稳定性产生重大影响。在这种改造后的高dr渗透电网结构中，如何实时预测和控制整个电网的总发电量将成为一项非常具有挑战性的任务。电网的运行将更有意识地以drr发电为基础，而不是以消费者负荷需求为基础。可能出现的主要问题是由于闪变、凹陷、膨胀及其谐波含量、频率控制等引起的电压畸变增加。为了解决这些问题，文献中提出了解决方案，例如增加备用DG机组的额定值以及使用存储系统来维持赤字实时负载需求。

Distributed Renewable Resources (DRRs) differ from conventional and fossil-fired resources in a fundamental way. Their sources (wind velocity and solar radiation in particular) cannot be controlled or stored. Further, renewable power generation often does not correlate with consumer load demand in real time due to its high intermittency. It may lead to one of the main causes of destabilizing the power system. In light of increased penetrations of these DRRs (50-60%) with the future grid, it will be difficult even for conventional power plants to participate effectively with great impact in maintaining stability of the network. In such reformed grid structure with high DRRs penetration, it will become a real challenging task to instantaneously predict and control total power generation in the entire grid. The operation of power grid will be more deliberately governed on the basis of DRRs generation rather than consumer loads demand. The main problems which may arise are increased voltage distortions in terms of flicker, sag, swell and its harmonic contents, frequency control etc. To solve such problems, solutions are presented in literature, such as, increased rating of a stand-by DG unit and employing storage system for maintaining deficit real time load demands. The demand side management is alternative solution for mitigating intermittency of the DRRs in the power system. The load power consumption is controlled such that load demand follow power generation. Load demand management methods are classified as load scheduling, use of energy storage systems (ESS), direct on-off control of non-critical loads etc. However most of these methods are suitable for load management in time frame of hours. They do not work in real time, except with the use of ESS. Recently, electric spring (ES) concept has been proposed as a smart load for demand management in real time. However, it has not been analyzed very much in terms of its design, efficient control and its worthiness under high penetration of wind and solar PV generation with distribution systems. Moreover, in near future, energy demand is expected to increase rapidly in the sector of transportation to supply plug-in electrical vehicles (PEVs). These charging stations of PEVs may be used as flexible loads to stabilize the grid. In view of these challenges, there is an immediate requirement for detailed investigation for technologies with distribution system to mitigate intermittency of DRRs. The main objectives of the proposed research project are as follows, Design, modeling, control, implementation and performance evaluation of selected topologies of smart loads to achieve loss minimization, technical upgradation, size reduction under increased penetrations of DRRs. Design, modeling and control for scheduling the dispatch of parking stations for PEVs under increased penetrations of DRRs to improve grid stability and customer satisfaction.