Investigation of Distributed Generation Rate-of-Change-of-Frequency Relays

抗孤岛能力是分布式发电并网的基本要求。**应用于沼气DG反孤岛检测的频率变化率（ROCOF）继电器经常由于电网扰动和DG输出功率振荡而受到 ** 骚扰跳闸。RTDS Technologies Inc.的客户 **（RTDS）在基于农场的沼气DG项目中正面临这样的挑战。在过去数年，RTDS的客户经常报告危险品滋扰性跳闸。为了解决这一问题，本项目将根据从位于渥太华的Schouten**Cornerview农场 ** 收集的历史现场测量结果，分析DG跳闸事件的原因 ** 并提供解决方案。基于DG频率变化的孤岛检测方法已被业界公认为最可靠的选择，作为这些方法的代表，ROCOF继电器已被广泛应用于DG应用中。然而，ROCOF继电器误动作在现场时有发生，DG频率 ** 振荡是导致此类误动作的主要原因之一。避免误跳的一种方法是为ROCOF继电器设置 ** 合理的参数。跳闸阈值、波形测量窗口、** 动作延时等参数，将影响ROCOF继电器响应。**该项目包括系统建模，理论分析和RTDS仿真分析，** 和最佳ROCOF继电器设置设计。RTDS将与卡尔顿 ** 大学的研究团队合作，分析电网扰动和ROCOF继电器参数对DG滋扰跳闸的影响，并 ** 提出设置ROCOF继电器的指导。研究工作的结果将有助于确定DG反孤岛保护的最佳 **ROCOF继电器设置，并大大减少不必要的DG跳闸。基本上，该项目将有利于公用事业公司，DG业主和DG咨询公司以协调和积极的方式采取行动，以确保在加拿大成功采用沼气DG。

Anti-islanding capability is an essential requirement for the grid connection of distributed generation (DG).**Rate-of-change-of-frequency (ROCOF) relays applied for biogas DG anti-islanding detection often subject to**nuisance trip due to grid disturbances and DG output power oscillations. clients of the RTDS Technologies Inc.**(RTDS) are facing such challenge for farm-based biogas DG projects. Frequent DG nuisance trips were**reported from RTDS's customers in the past few years. To solve the problem, this project will analyze reasons**of DG trip events and provide solutions, based on historical field measurements collected from the Schouten**Cornerview Farms located in Ottawa.**The islanding detection approaches based on DG frequency variation have been recognized as the most**reliable option by industry and as a representative of these methods, ROCOF relays have been widely used in**DG applications. However, nuisance trips of ROCOF relays often happened in the fields, and DG frequency**oscillation is one of the main reasons leading to such false operations. One way to avoid nuisance trips is to set**reasonable parameters for ROCOF relays. The parameters such as trip threshold, waveform measuring window,**operation time delay, etc., will affect ROCOF relay responses.**The project includes the activities of system modeling, theoretical analysis and RTDS simulation analysis,**and optimal ROCOF relay setting design. RTDS will work in collaboration with the research team of Carleton**University to analyze the impact of grid disturbances and ROCOF relay parameters on DG nuisance trips and**propose guidance on setting ROCOF relays. The findings of the research work will help to determine optimal**ROCOF relay settings for DG anti-islanding protection and significantly reduce the unnecessary DG trips.**Essentially, the project will be beneficial for utility companies, DG owners and DG consulting companies to**act in a coordinated and proactive manner to ensure the successful adoption of biogas DG in Canada.