An adaptive load shedding methodology for renewable integrated power systems.

Abstract

System stability issues regarding frequency and voltage in modern power systems are growing in importance as they incorporate more and more complex components. To ensure a sustainable, pollution-free power generation, modern power systems are designed to incorporate more renewable generation sources than traditional ones. Therefore, in the event of a large-scale disruption event, conventional load-shedding strategies are unable to keep the voltage and frequency limit below the threshold value. The suggested approach takes into account this issue by rating load buses in relation to relevant frequency changes, their voltage stability, system load damping coefficients, and the introduction of green energy sources in place of fossil fuel-based ones. Battery Energy Storage Systems (BESS) are used in the proposed method to minimize load shedding amount required for conventional schemes. After determining the amount, the scheme dynamically chooses feeders as per relative weightage of the stability components (voltage, frequency) to ensure that the overall load shed amount is near to the calculated value. To verify this, the scheme is tested on IEEE 39 bus with python scripted simulation. There are four scenarios considering 250 MW, 500 MW and 1500 MW injection of PV based power generation sources with conventional generation loss of 800 MW and 1000 MW. The threshold frequency is considered 49.10 Hz. The total amount of BESS is 300 MW. For every scenario, it has been found that the methodology successfully maintains the system frequency above 49.10 Hz with a minimal amount of load shedding. Hence, the proposed methodology is able to maintain frequency stability for a modern power system with large-scale PV generation through adaptive feeder selection for load shedding.