Protection of the Next Generation of Power Distribution Systems

在智能电网和绿色能源倡议的推动下，新的功能和技术正在传统电力系统中激增。该研究计划将应对这些新兴发展所带来的日益严峻的继电保护挑战，从而确保下一代电力系统的故障恢复能力和可靠性。在短期内，重点将放在分配系统上，并将研究以下问题。 1.微电网保护：尽管现有的配电继电器不能可靠地保护微电网，但迄今为止还没有制造出微电网专用继电器。为了解决这一差距，微电网继电器将通过调查的非常规序列组件，波形特性和分布式发电（DG）单元的故障电流和电压的大小。继电器的主要保护单元由许多监控元件控制，这些监控元件对继电器的成功操作至关重要。将研究微电网中可能受到影响的两个继电器监控元件。 2.光伏（PV）农场保护：太阳能PV是连接到配电系统的DG中的常见技术。光伏电站因内部故障而遭受重大损失。此外，现有光伏发电场保护装置的故障最近导致了几起火灾事故。该项目将基于串电流波形和串电压分布的相关性分析开发光伏发电场保护方法。 3.配电系统的相量测量：广域测量系统（WAMS）正在扩展到电压和电流污染程度较高的配电系统。另一方面，需要在分配一级进行更精确的测量。本研究将解调器整合于相量量测演算法中，有助于消除讯号污染的影响。 4.低压（LV）直流系统的保护：虽然继电器通信可以解决低压直流系统的保护挑战，但对于大多数低压系统来说，通信网络很难在经济上得到证明。这项研究将制定新的中继通信方案的低压系统，使用新兴的低成本无线技术，如蜂窝网络。然后，考虑到所采用的无线技术的特性，将开发自适应保护方法。 通过该计划开发的改进的配电保护方法对于（i）实现微电网，（ii）更高的可再生DG渗透率，（iii）更准确的配电系统WAMS，以及（iv）具有成本效益的配电继电器通信至关重要。加拿大下一代配电设施的故障恢复和可持续运营是上述项目的贡献之一。该计划的其他受益者包括继电器制造商和太阳能光伏行业。

Driven by the smart grid and green energy initiatives, new features and technologies are proliferating across the legacy power system. This research program will respond to the rising protective relaying challenges imposed by these emerging developments, thus ensuring the fault resiliency and reliability of next-generation power systems. In the short term, the focus will be on distribution systems, and the following issues will be researched. 1. Microgrid protection: Even though existing distribution relays fail to reliably protect microgrids, no microgrid-specific relay has been manufactured to date. To address this gap, a microgrid relay will be developed by investigating the unconventional sequence components, waveshape properties and magnitude of the fault currents and voltages of distributed generation (DG) units. The main protection units of a relay are controlled by a number of supervising elements, which are critical to successful relay operation. Two relay supervising elements that can be affected in a microgrid will be researched. 2. Photovoltaic (PV) farm protection: Solar PV is a common technology in the DGs connected to distribution systems. PV farms sustain heavy losses due to internal faults. Moreover, malfunction of the existing PV farm protective devices have recently resulted in several fire incidents. This program will develop PV farm protection methods based on correlation analysis of string current waveshapes and string voltage distribution. 3. Phasor measurement for distribution systems: Wide-area measurement systems (WAMS) are being extended to distribution systems, where the voltages and currents include higher levels of pollution. On the other hand, more-precise measurements are required at the distribution level. This research will integrate demodulators in the phasor measurement algorithms and so help to eliminate the effect of signal pollution. 4. Protection of low-voltage (LV) dc systems: While relay communication can address the protection challenges of LV dc systems, a communication network is hard to justify economically for most LV systems. This research will formulate new relay communication schemes for LV systems, using emerging low-cost wireless technologies such as cellular networks. Then, adaptive protection methods will be developed taking into account the properties of the wireless technology adopted. The improved distribution protection methods developed through this program will be essential to (i) realization of microgrids, (ii) higher penetration of renewable-based DGs, (iii) more-accurate WAMS for distribution systems, and (iv) cost-effective distribution relay communication. Fault resilient and sustainable operation of next-generation Canadian distribution utilities are among the contributions of the above projects. Other beneficiaries of this program include relay manufacturers and the solar PV industry.