Power System Analysis (Slides)

This panel session contains the following presentations:
1. PID Controller Tuning Performance Evaluation for an Isolated Power System
Over the years, efforts to improve the accuracy of system control, optimization, and stability of electrical power system have been a major source of concern. The design and deployment of PID controllers for managing load frequency deviations in power system is gaining more traction owing to PID controllers' robust nature and simple form. While manual PID tuning is based on set gain parameters and only provides the essential stability for static systems, the dynamic nature of power systems necessitates the use of more intelligent tuning techniques. In this work, an isolated power system requiring a Load Frequency Control (LFC) by the application of a PID controller is designed in the MATLAB/Simulink environment. To acquire the PID gain parameters for an optimum dynamic load frequency control, several optimization procedures are applied. Genetic algorithms (GA) and Particle Swarm Optimization (PSO) technique were used to determine the proportional gain (KP), integral gain (KI), and deferential gain (KD) of the controller. Artificial Neural Network (ANN) training was is also caried out for the PID tuning and the comparative analysis of the results obtained shows that the Particle Swarm optimization (PSO) has the best performance, with an overshoot of 0.58 percent and a settling time of 0.52 seconds.

2. Study on the Electrical Equivalent Circuit Model of Lightning Fault Cause in Power Grid System
Transmission line systems are exposed to various fault causes that can reduce the grid performance. One of the fault causes is due to lightning strike. The judgement of the lightning fault cause is usually done after the tripping is detected by the protection operation system and its consume time. Another method to conclude the lightning fault cause is detected using lightning map sensor but, the supplement method is quite expensive and did not employed in the whole grid system in Malaysia. Furthermore, the grid systems are utilized with the Digital Fault Recorder (DFR) as an intelligent electronic device to detect and restore the fault data. By using the voltage and current waveform data obtained from the DFR, the fault behavior could be studied. Therefore, in this paper, an equivalent circuit model has been investigated to understand the correlation between the fault phenomena due to lightning and its voltage and current profile acquired from the DFR.

3. Optimal Topology of LVAC in a Rural Village Using Water Cycle Algorithm
Risk assessment methods for electrical power system network based on the historical extreme weather events, also known as High Impact Low Probability events (HILP) helps support system operators to develop and implement effective resilience strategies. To support the power system's resilience, preventive and corrective technologies have been proposed, assessed, and implemented. Additionally, several risk managements tools have been utilized for the system analysis, one being Failure mode and Effects analysis (FMEA) widely used to improve the reliability of the electricity grids by considering different factors to provide the detailed risk assessment. Although FMEA analysis has been reported to help improve the reliability of system it has not been assessed for power system resilience measures. Therefore, this paper attempts to introduce the FMEA to assess and help improve the power system resilience by proposing location-based risk assessment approach to analyze the risk of outages due to the extreme weather events for different locations in North Island major cities of New Zealand. This FMEA based analysis considers the wind gusts data by estimating the severity of the data set with regards to loss of load due to high wind gust, and the probability of failure detection in the selected region. The weather data analysis has been tested and visualized with the actual transmission network data to identify the risk priority number for different locations/zones based in the Waikato region, New Zealand.

4. Field Current Compensation Factor in Synchronous Generator Dynamic Model for Power System Study
This article analyzes and tests the field current compensation factor which has been used in the GENQEC generator model with proven high steady-state accuracy and good dynamic performance. Analysis on synchronous generator basic equations and second-order generator equivalent circuit provides the theoretical basis of the field current compensation factor. The concept of generator field current compensation based on zero power factor characteristics in the linear region of the magnetic circuits brings a new aspect for solving the century-long field current accuracy issue in synchronous generator modeling. With proven simplicity and effectiveness, the application of the field current compensation factor can be a comparable or better alternative to Potier reactance and other methods which modify the variable in saturation functions.

5. A Multi-Instance, Multi-Timestep Co-Simulation Approach for Power System Simulation Tools
This paper proposes a Co-Simulation concept that couples two or more simulators utilizing different timesteps. The interprocess communication is handled via a shared memory based algorithm. Unfavorable effects due to the conversion between time steps are eliminated using filters. The electrical representation is based on a Bergeron line model utilizing the dependency of time and location of travelling waves along transmission lines. The proposed Co-Simlation has minimal impact on accuracy while greatly reducing simulation execution time.