engleski

System Integrity Protection Scheme Based on PMU Adaptive Power Swing Protection

The System Integrity Protection Scheme (SIPS) is a specialized protection scheme which differs to a great extent from the common protection, especially in its main intention. It is designed for integrity protection, failure prevention and mitigation of disturbance consequences in the whole power transmission system (PTS). This requires specialized circuitry and software solutions, which cannot be obtained from the market as a finished product, but have to be developed and tested in real time. Input parameters for establishing the SIPS in the PTS could be (and in this case will be) synchronized measurements of voltage and current phasors, obtained from the Phasor Measurement Units (PMUs), as a globally acknowledged Smart Transmission Grid technology. In opposite, the local protection schemes are oriented towards local measurements of RMS values, and thus do not ensure the power system integrity in case of a fault. The realization requires that the SIPS is added to the existing Wide Area Monitoring, Protection and Control (WAMPAC), based on synchronized measurements in order to maintain system integrity and avoid possible blackouts. The SIPS architecture can be distributed or centralized ; based on events, parameters, response or combination. Also, there are two basic solutions: the flat (measuring and operating elements are in the same location) and hierarchical architecture (local measurements are sent to multiple control locations). Although the SIPS can help to increase power transfer limits, its primary task is to reduce the intensity and frequency of blackouts and to improve security of the power system. Rapid development of technologies for the PTS protection and control, such as communications, controllers and PMUs, and analytical techniques for applications, has enabled the implementation of the SIPS concept, which can encompass several applications. In this paper the focus is on algorithm that anticipates optimal PMU placement and then uses adaptive power swing protection based on traditional IEDs supported by synchronized measurements. By using such approach due to large disturbances in (PTS) the system can avoid possible blackouts due to merge operation of traditional power swing protection and WAMPAC. The proposed SIPS system is tested on specific area in Croatian transmission system (costal part) that is a mix of Hydro Power Plants, Wind farms and radial, costal transmission lines over islands. In the paper it is shown theoretical results run on specific scenarios that usually activates traditional power swing protection that can at worst case result to system blackout.

Phasor Measurement Unit, System Integrity Protection Schemes, Wide Area Monitoring, Protection And Control, Power Swing Protection

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