Executive Summary : | Interconnected power system is continuously subjected to large or small disturbances in terms varying load and generation pattern in real time, which causes intra-area and inter-area oscillations. These features sometime induce system break down or blackout. Hence, it is very essential to damp out these oscillations. The default damping effect of system is due to the presence of high inertia of the system due to large capacity synchronous generators. As renewable generation begins to replace conventional generation, however, the ability of the system to resist these deviations decreases. Modern generating plants such as wind and solar power plants are made up of generating units that connect to the power system through frequency converters. These converters, however, are most often controlled in such a way that operation of the generating plants is independent of the system frequency, resulting in reduced system inertia. The same is true of motor loads that utilize power electronics. Import and export of electricity through HVdc connections will also mean a shift in the location of inertia in the power system.
The annual growth in power generation in India indicates a tremendous growth in renewable generation since 2014-15. The growth rate of conventional generation is gradually decreasing showing that the inertia of Indian power system is reducing, which may lead to a more unstable system. Power systems consist of many components distributed across wide geographic areas. A sudden increase or decrease in load or generation in these systems results in swings in power transfer between regions, called inter-area oscillations. Damping these inter-area oscillations is crucial for maintaining a secure and reliable power grid. In this proposal, we proposed distributed control schemes that can be used to improve the small-signal stability of large power systems. Implementations include the modulation of power transfer along a High Voltage DC transmission line as well as injecting power from distributed energy resources. Furthermore, the practical challenges arise from using remote measurements for feedback signals. Specifically, the time delays associated with synchrophasor-based measurements and the effect of time delays on stability of the distributed control system will be studied.
The case of Eastern Regional Grid (ERG) will be considered for this research proposal. The analysis will be carried out using real time digital simulator (RTDS) and real time digital monitoring system (RTDMS). |