For those interested in pursuing a Master’s or PhD in the fields of fault location, protection schemes, or any other area of power systems, feel free to PM me personally. We can provide training in Matlab/ATPDraw. 🙂
The deadline to apply for MyBrain20 is August 21, 2024.
Assalamualaikum and Greetings..
I have conducted a workshop for postgraduate students and lecturers on how to use Matlab and Simulink software to model and simulate power systems. I hope the knowledge shared will be beneficial to everyone.
On December 20, 2023, I and my students studying Power System Protection & Switchgear visited the Perlis Power Plant for an industrial tour. The aim was to give students hands-on exposure to a crucial element of the power system—the power plant. Initially, we received a comprehensive briefing on the power plant's operations, covering organizational structures, company management, operational systems, and power generation control. This particular plant employs a combined cycle system, relying on natural gas as its primary fuel source for generating electricity. Within this setup, there exist two main turbines: the primary turbine, fueled by burning natural gas, and the secondary turbine, activated by steam derived from the primary turbine's combustion heat. Following the briefing, participants had the opportunity to witness various parts of the power plant installation, including the turbine room, step-up transformers, grid connections, water storage facilities, and the power generation control room (SCADA).
Restricted Earth Fault (REF) relay is used as a primary protection alongside differential relays for safeguarding transformers from ground faults in both the high-voltage (HV) and low-voltage (LV) windings.
Each HV and LV winding has its own REF relay. This relay isn't able to detect phase-to-phase faults or three-phase faults (without touching the ground) because its protection boundary is from the CT on one side (primary/HV) to the CT connected to the neutral on the primary/HV side of the primary/HV winding.
For the secondary/LV winding, the protection boundary is from the secondary/LV side CT to the CT connected to the secondary/LV neutral.
The REF relay can be used to protect both Y-Y and Y-Delta transformers. In the case of a Y-Delta transformer, the neutral earthing resistor (NER) is connected to the secondary/LV winding to provide a neutral connection for return current and transformer connection.
Figure 1 illustrates the operation of the REF relay. When a ground fault occurs in either the primary/HV or secondary/LV winding, no current flows through one of the CTs (input to the REF Relay), resulting in residual current entering the REF relay, exceeding the pickup current setting. The relay then sends a signal to the Master Trip relay, which subsequently sends a tripping signal to both breakers, the primary/HV, and the secondary/LV. There's no tripping delay as the REF relay acts as the primary protection for the transformer alongside the Differential relay.
Transmission line faults can arise due to various reasons, and they can be categorized into several causes:
1. Weather Conditions - Adverse weather conditions like lightning, heavy storms, strong winds, ice, or snow can cause faults by physically damaging the transmission lines or creating conditions conducive to electrical faults.
2. Equipment Failure - Malfunction or failure of components such as insulators, conductors, transformers, switches, etc can lead to faults along the transmission line.
Transient Fault
Permanent Fault
