LVRT compliance monitoring of renewable energy generating units
Student name: Mr Soudipan Maity
Guide: Dr Naqui Anwer
Year of completion: 2018
Host Organisation: Department of Energy Science and Engineering, Indian Institute of Technology, Bombay
Supervisor (Host Organisation): Dr Zakir H. Rather
Abstract: Variabilities associated with renewable energy significantly affects how power systems with high penetrations of it operate. In India, since wind energy forms the largest share of installed renewable energy capacity, several measures for maintaining voltage stability, load-generation balance, frequency control, and power factor control is being enforced through the Indian Electricity Grid Code (IEGC) to maintain system security and stability. The Low-Voltage Ride-Through criterion is one such crucial requirement in the grid code for connection of large-scale renewable power plants to the power system. LVRT schemes in the grid code require the RE generating units to remain connected to the network even when the voltage at the point of common connection on one or all phases drops below the threshold specified by the grid code standards and provide grid support at the plant terminal. However, these units are often not put through strict LVRT compliance tests at regular intervals under operating conditions, and therefore can pose a serious threat to the transient stability of the grid during system contingencies. Although there have been significant advancements in devising technologies to put wind and solar power plants to test for LVRT compliance, these involve on-site testing of individual generating units and these technologies are not widely available. This report attempts to bridge the gap by proposing a new strategy to monitor the online LVRT compliance of a renewable energy generating station by the use of the network of Synchrophasor Measurement Units (SMUs) located at the important power system nodes, which can capture the time-stamped power system dynamics essential for analysing disturbance and post-disturbance scenarios. Several scenarios of placement of SMUs have been taken into consideration and a case study has been performed on a test system to evaluate the technique for LVRT testing using network reduction techniques.
Keywords: LVRT, SMU, Compliance, Monitoring, Faults