Utilisation of synchronous condensers for improved damping in power systems with high renewable penetration

Abstract

With ever increasing variable renewable energy (VRE) and subsequent displacement of conventional synchronous generation (CSG), system strength and inertia have been steadily declining in power system grids around the world. A mitigation to the aforementioned problem is installation and operation of synchronous condensers (SC) for provision of system strength and inertia. While the synchronous condenser is a mature and proven technology, the technology has not been fully utilised, particularly in its ability to provide additional damping to system inter-area modes via Power Oscillation Damper (POD) controllers. Synchronous condensers can provide inertia and modulation of terminal reactive power and voltage (via the excitation system) to impact the system power flows such that it can provide a positive contribution to system damping. This paper examines the implementation of a synchronous condenser in conjunction with a POD, in a network with high renewable generation, to dampen inter-area modes. Firstly, we investigate a method to determine the ideal location and monitoring Bus of a synchronous condenser, for damping of inter-area modes. Subsequently, the inertia time constant and POD settings are optimised to provide adequate modulation of the SC terminal voltage and reactive power for increased damping of interarea modes. Finally, large and small-signal disturbances are considered with and without the POD to demonstrate the device effectiveness.