Load demand management with high renewable energy penetration in distribution systems

分布式可再生资源(DRR)在根本上不同于传统资源和化石燃料资源。它们的来源(特别是风速和太阳辐射)无法控制或储存。此外，可再生能源发电由于其高度间歇性，往往与消费者的负荷需求不是实时相关的。这可能导致电力系统不稳定的主要原因之一。鉴于这些DRR(50%-60%)对未来电网的渗透率不断增加，即使是传统发电厂也很难有效参与，对维持电网的稳定产生很大影响。在这种DRRS普及率高的改造电网结构中，实时预测和控制整个电网的总发电量将成为一项真正具有挑战性的任务。电网的运行将更加谨慎地根据DRRS发电量而不是用户负荷需求进行管理。可能出现的主要问题是闪变、凹陷、隆起及其谐波含量、频率控制等方面的电压失真增加。为了解决这些问题，文献中提出了解决这些问题的方法，如增加备用DG机组的额定功率和使用存储系统来维持实时负荷需求不足。 需求侧管理是缓解电力系统DRR间歇性的替代方案。负荷功率消耗受到控制，使得负荷需求跟随发电。负荷需求管理方法分为负荷调度、利用储能系统(ESS)、非关键负荷的直接开关控制等，但这些方法大多适用于小时范围内的负荷管理。它们不是实时工作的，除非使用ESS。最近，电动弹簧(ES)的概念被提出作为一种智能负荷，用于实时需求管理。然而，在风能和太阳能光伏发电与配电系统的高渗透率下，它的设计、有效控制以及它的价值还没有得到太多的分析。此外，在不久的将来，预计交通运输领域的能源需求将迅速增长，以供应插电式电动汽车(PEV)。这些电动汽车充电站可以作为灵活的负载来稳定电网。 鉴于这些挑战，迫切需要对分配系统的技术进行详细调查，以缓解DRR的间歇性。拟议研究项目的主要目标如下： 对选定的智能负载拓扑进行设计、建模、控制、实施和性能评估，以在DRR渗透率增加的情况下实现损耗最小化、技术升级和尺寸缩小。 设计、建模和控制在DRR渗透率增加的情况下调度电动汽车停放站的调度，以提高电网稳定性和客户满意度。

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.