Load Switching Scada-Based on Three-Phase 15 MW And 20 MW Synchronous Generators

Abstract

Pupuk Iskandar Muda (PT. PIM) generates electricity from two main gas turbine generators (GTGs), one with a capacity of 15 MW and 20 MW respectively. The generator's performance can only be at its best if its operation remains stable, even when it exceeds capacity or faces potential damage from its outdated engine. When the electrical load increases and reaches its maximum capacity, load transfer is commonly accomplished through synchronous generator operation. However, the synchronisation may lead to generator failure. This study focuses on (1) examining the PT's load transfer process of Iskandar Muda fertiliser, operated based on Supervisory Control and Data Acquisition (SCADA), and (2) evaluating the influence of voltage and frequency on this process. This study utilised qualitative methods by directly observing field data at PT PIM. The results obtained indicated that the load transfer process at PT PIM is carried out on two simultaneously operating gas turbine generators using SCADA-based technology. The load transfer process employs two methods, namely fast load transfer and slow load transfer. Changes in the decrease in power in GTG 1 and the increase in power in GTG 2 can cause the generator's rotational speed and the governor's setting point to change, resulting in changes in the voltage and frequency characteristics. The load transfer is performed regularly in stages of 200 kW to maintain the stability of the generator condition. However, a transfer of 1 MW is executed during the final stage to avoid overloading and a potential burden on one of the generators. GTG 1 experiences a voltage increase of 0.018% and a frequency increase of 0.0059% due to load changes in the two generators, whereas GTG 2 has a voltage increase of 0.018% and a frequency increase of 0.0019% when the load shifts from 1 MW to 9 MW.