Program: 2nd Session on Friday (11:00-12:20)

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F2-1Modeling & Computing Methods

11:00 SVD-based Reduced-Order Rational Approximation for EMT Analysis

Abner Ramirez (Center for Research and Advanced Studies of Mexico, Mexico); Edgar Medina (CINVESTAV-Guadalajara, Mexico)

This paper introduces a simple and effective model order reduction (MOR) approach based on singular value decomposition (SVD) and aimed to electromagnetic transient (EMT) analysis. The proposed approach initially adopts a rational approximation obtained by the vector fitting (VF) software tool for an arbitrary frequency range. Then, it applies SVD-based truncation separately to low-frequency range and to the error given by the original function and the low-frequency approximation in the high-frequency range. Finally, the resultant reduced approximations are assembled for EMT solution allowing the use of two different time-steps. The obtained reduced-order model achieves computational savings compared to the original full-size system given by VF. A case study is presented to validate the proposed method.

11:20 Non-Intrusive Load Monitoring Using Wavelet Design and Co-Testing of Machine Learning Classifiers

Jefferson Chung (University of Ontario Institute of Technology, Canada); Jessie Gillis (University of Ontario Institute of Technology, Canada); Walid Morsi (University of Ontario Institute of Technology, Canada)

This work aims to investigate the effect of implementing co-testing in Non-Intrusive Load Monitoring. Wavelet Design is used to extract features from the switching transients of loads. The features extracted are evaluated on a real test bed using One-Against-the-Rest and co-testing approaches. The results show the effectiveness of both approaches and it is seen that classification using co-testing provides a higher overall classifier accuracy. This is due to a significant decrease in misclassification occurrences.

11:40 A Single-Phase Dynamic Phasor Estimation System: Analysis of Performance and Computational Cost

Pablo Marchi (CSC-CONICET, Argentina); Francisco Messina (Universidad de Buenos Aires, Argentina); Leonardo Rey Vega (University of Buenos Aires, Facultad de Ingeniería & CONICET, Argentina); Cecilia Galarza (University of Buenos Aires, Argentina)

This paper presents a new single-phase technique for dynamic phasor estimation using a sample by sample digital processing approach. The estimation process is performed in three stages. In the first stage, an efficient FIR filtering of
the input signal is made to reject out-of-band and harmonic interference. The second stage uses a parameterized EPLL to track amplitude, phase, frequency and ROCOF. The final stage compensates the delay and any possible phase and amplitude
distortion. The proposed design is compared against a well known window DFT method known as IpD²FT, which requires a large buffer and iterative process for each report. The goal is to develop a PMU system compliant with the IEEE Std. C37.118.1a and compare both algorithms in terms of performance and computational cost.

12:00 Power System Tracking State Estimation Based on Stochastic Fractal Search Technique Under Bad Measurements Conditions

Hossam Mosbah (Dalhousie University, Canada); Mohamed El-Hawary (Dalhousie University, Canada)

Tracking State Estimation (TSE) predicts potential security contingencies. This paper discusses the application of Fractal Search which is a stochastic meta-heuristic algorithm under various scenarios including normal operation where load fluctuates linearly and noisy and bad data measurements introduced at different time instants during the study period. The proposed algorithm is tested on IEEE 5, 14, 30, and 57 bus systems and the results are compared with those obtained Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) to demonstrate the validity of the proposed approach.


11:00 Mitigation of Ferroresonance in Line Commutated HVDC Converter Interconnected with Series Compensated Overhead Line Transmission System

Jwala Laxmi Narasimha Rao (ABB & ABB Global Industries and Services pvt ltd, India); Gaurav Bansal (ABB Global Industries and Services Private Limited, India); Soubhik Auddy (ABB Global Industries and Services pvt ltd, India)

Ferroresonance is a non-linear resonance which can typically occur when a saturable magnetizing inductance forms a resonance circuit with a capacitor. An example of such a resonance condition can be a system configuration where an overhead transmission line with series compensation terminates into an HVDC converter transformer. Such a configuration may lead to post fault ferroresonance oscillations. Mitigation of ferroresonance using converter controls is a simple and economically attractive solution when compared to other solutions such as installing additional equipment in the network. This paper proposes a damping controller to mitigate ferroresonance oscillations for a HVDC system.

11:20 A New Coordinated Design of UPFC Controller and PSS for Improvment of Power System Stability Using CPCE Algorithm

Amin Khodabakhshian (University of Isfahan, Canada); Mohammad Reza Esmaili (University of Isfahan, Iran); Mosayeb Bornapour (University of Isfahan, Iran)

This paper presents a new method for coordinately tuning the parameters of UPFC controller and power system stabilizer (PSS) as well as determining the PSS location to enhance the stability of power system by using a new hybrid particle swarm optimization based co-evolutionary cultural algorithm, so called culture-PSO-co evolutionary (CPCE). Nonlinear simulations are implemented on the IEEE 39-bus power system. The results imply the effectiveness of proposed method for damping out power system oscillations.

11:40 Comparison of Phase Shifting Transformer and Unified Power Flow Control Based Interphase Power Controllers

Khalid Elamari (Concordia University, Canada); Luiz A. C. Lopes (Concordia University, Canada)

The basic interphase power controller (IPC) presents the interesting features of simplicity and low cost despite being less flexible than most FACTS controllers. A compromise performance can be achieved by replacing the phase shifting transformers (PSTs) with a reduced rating unified power flow control (UPFC), also known as Unified Interphase Power Controller (UIPC). This comparison is the main goal of this paper. The control variables of the UPFC are computed based on an optimization procedure to minimize a given cost function. The results show not only the higher capability of the UIPC to control the current flow through the transmission line but also shows that the UIPC achieves his task with less losses.

12:00 Comparison of Modern STATCOM and Synchronous Condenser for Power Transmission Systems

Sergey Kynev (Siemens AG, Germany); Georg Pilz (Siemens AG, Germany); Heino Schmitt (Siemens AG, Germany)

This paper presents a comparison between Synchronous Condenser and STATCOM as a dynamic source of reactive power. It focuses on the differences in the operating principles, steady-state and dynamic performance. Although both devices are able to provide capacitive and inductive current to the network, the dynamic behavior is principally different. The difference in the amount of the injected current as a response to network contingencies is explained by means of V/I diagrams. Another factor is the speed of the response. To consider it, the comparison is done for two time periods – transient (0.5-1sec.) and an emergency period (few seconds) after a contingency occurs. The paper addresses the recent growing interest in synchronous condenser application, due to its unique ability to contribute to the system inertia and short-circuit power. This paper also includes the comparison of losses, since it is a growing concern and an important selection criterion between Synchronous Condenser and STATCOM.