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，新功能和技术正在整个传统电力系统中激增。这一研究计划将应对这些新兴发展带来的日益增长的继电保护挑战，从而确保下一代电力系统的故障弹性和可靠性。在短期内，重点将放在配电系统上，并将研究以下问题。*1.微网保护：尽管现有的配电网继电保护不能可靠地保护微网，但到目前为止还没有制造出专门针对微网的继电器。为了弥补这一空白，将通过研究分布式发电(DG)机组的非常规顺序分量、波形特性以及故障电流和电压的大小来开发微电网继电保护。继电保护的主保护单元由多个监控元件控制，这些监控元件是继电保护动作成功与否的关键。将研究微电网中可能受到影响的两个继电监控元件。*2.光伏(PV)发电场保护：太阳能光伏是接入配电系统的分布式发电系统中的一种常见技术。光伏农场由于内部故障而蒙受严重损失。此外，现有光伏农场保护装置的故障最近导致了几起火灾事件。该计划将开发基于串电流波形和串电压分布的相关性分析的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)正被扩展到配电系统，其中的电压和电流包含更高水平的污染。另一方面，需要在分布层面上进行更精确的测量。这项研究将把解调器集成到相量测量算法中，从而有助于消除信号污染的影响。*4.低压直流系统的保护：虽然继电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。这项研究将利用新兴的低成本无线技术，如蜂窝网络，制定适用于低压系统的新的中继通信方案。然后，将考虑所采用的无线技术的特性来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将对(I)实现微电网、(Ii)基于可再生的分布式电源的更高普及率、(Iii)配电系统更准确的WAMS以及(Iv)经济高效的配电继电通信至关重要。加拿大下一代配电设施的故障恢复能力和可持续运行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产业。**

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.**