Obed Muhayimana

@vut.cz

Researcher UEEN VUT
Brno University of Technology



           

https://researchid.co/muhayimana

RESEARCH INTERESTS

Power System and Renewable energy

7

Scopus Publications

Scopus Publications

  • A Comparative Study Between Synchrophasor-Measurement-Based Linear and Nonlinear State Estimation in Power Systems †
    Ali Aljazaeri, Petr Toman, and Obed Muhayimana
    MDPI AG
    The evolution of phasor measurement units (PMUs) marked a significant development in the field of electrical engineering. The integration of PMU-based linear state estimators or the augmentation of SCADA measurements with PMU measurements has emerged as a promising solution to address the limitations of conventional state estimation. The utilization of PMU measurements has been demonstrated to effectively address measurement errors, leading to the precise determination of the system’s state within a single iteration. This article provides a comprehensive discussion of both linear and nonlinear state estimation computational processes. A comparative analysis is conducted to assess their performance. PMU-based state estimator models are proposed based on different PMU locations and are further examined under abnormal conditions. The results are compared with the simulated results from a Simulink PSCAD model of the IEEE 14-bus system to ensure validation. The test results demonstrated that the proposed models outperformed the conventional model in terms of robustness and accuracy. The estimated and simulated states matched during both normal and abnormal conditions, demonstrating the model’s capability to track sudden changes in voltage profiles. This article promotes further investigations to develop new control and protection functions using this model.

  • Verification of PMU Optimal Placement in Power Distribution Networks Using Synchrophasor Measurements and Real-Time Simulation
    Obed Muhayimana, Petr Toman, Abir Lahmer, Mohammed Laamim and Abdelilah Rochd

    Total power system observability is a key feature for the electrical system's monitoring, control, and protection. Phasor measurement units (PMUs) which are presently deployed in electrical power systems (EPSs) have demonstrated their effectiveness in real-time monitoring and network control. They handle different phenomena, providing synchrophasor measurements in normal and abnormal working operations, even for systems with fast-changing dynamics such as active distribution networks (ADNs), by capturing fast transients of the systems. The PMU's high cost is the main setback to their application, and their massive deployment in electrical networks would be a non-realistic and non-cost-effective practice. Therefore, an optimal number of PMUs placed in well-selected and appropriate positions for the total network observability is substantial. This work verifies the PMU Optimal Placement in an Electric Distribution Network Using Synchrophasor Measurements and Real-Time Simulations. The IEEE 14-bus test system, the Integer Programming Procedure method for optimizing the PMU placement, and the real-time simulation of faults in different points of the system were the main approaches used to conduct the work.

  • Comparative Study between Model-in-the-Loop Offline and Real-Time Simulations for Phasor Measurement Units
    Obed Muhayimana, Mohammed Laamim, Ali Aljazaeri, Abdelilah Rochd, and Petr Toman
    IEEE
    Today's distribution networks are transitioning from traditional power grids with passive loads and unidirectional power flow to more complex active distribution networks (ADNs) with high penetration of intermittent distributed energy resources (DERs) and loads with fast-changing dynamics. These changes made the distribution system's planning, control, and monitoring very challenging defying existing control tools such as Supervisory Control and Data Acquisition (SCADA). The deployment of Phasor Measurement Units (PMUs) in electrical networks constitutes a powerful tool in mitigating the faced challenges. This paper analyses and tests the PMU block provided in the library of the R2021b Matlab together with a proposed PMU model, in different system working conditions, using model-in-the-loop (MIL) offline and real-time simulations.

  • Test of a Phasor Measurement Unit Model in the System Fault Conditions
    Obed Muhayimana, Petr Toman, Vaclav Vycital, and Silas Tuyishime
    IEEE
    The reliability and stability of a power system is based on its ability and rapidity in tackling its fault conditions. One of the most highly responsive tools used in this regard is the phasor measurement unit (PMU). PMUs provide synchronized data of voltages and currents, availing actual information on the state of the electrical network, granting required system observability, simplifying thus the operation and planning processes. They collect every digitalized data samples and transmit them instantaneously to the controller to compare them with the predefined data of the phasors. As result, appropriate control actions can be taken based on fine-grained data from the network. This study tests the PMU model in Matlab/Simulink and compares its simulation results with the results provided by a PMU block existing in the R2022b Matlab library, for an electrical system during normal operation, symmetrical, and non-symmetrical fault conditions.

  • Design and Verification of a Phasor Measurement Unit Model Using Matlab
    Obed Muhayimana, Petr Toman, Vaclav Vycital, and Viktor Jurak
    IEEE
    Todays power systems are becoming more and more complex due to the continuous increase in energy demand and high proliferation of intermittent renewable resources. Therefore, the system’s control and monitoring became very challenging. The usage of highly responsive phasor measurement units (PMUs) is one of the solutions that are making possible the real-time control and monitoring of electric systems. The available PMU block in the matlab/Simulink library is designed to provide only the magnitude, phase angle, and frequency of the positive-sequence component of a three-phase signal. This is a limitation when there is a need to analyze the real-time situations in all phases considering all symmetrical components in order to get accurate results, especially in case of unsymmetrical systems and more specifically in case of faults with ground current flows. This study develops a phasor measurement unit model in Matlab/Simulink, using Fourier Transforms (FT) and phase-locked loop (PLL) as phasor magnitude, phase angle, and frequency estimation tools, and then compares the results with the real PMU measurements.

  • A Review on Phasor Measurement Units and their Applications in Active Distribution Networks
    Obed Muhayimana and P. Toman

    Due to the progressive increase in integrating intermittent distributed generations (DGs), the proliferation of distributed energy resources (DER), and loads with the fast dynamic changes, the planning, monitoring, and operation of distribution networks are becoming a challenge. This is a transitional stage faced by today’s distribution systems from traditional passive networks characterized by unidirectional power flow to active ones with bidirectional power flow and very dynamic characteristics. The application of the recently developed phasor measurement units (PMU) which can provide up to 120 time-tagged measurements per second, can effectively handle the challenges. However, these PMUs need to have appropriate characteristics related to the distribution network vulnerability factors. This work explores and reviews distribution phasor measurement units, their applications, and their optimal placement in active distribution networks. It aims to provide a basic understanding of existing situations and the contribution of PMUs in handling challenges caused by the dynamic aspect of current distribution systems.

  • Overview on Synchrophasors Technology and Trend of their Application in Electrical Network Protection
    Obed Muhayimana and Petr Toman
    IEEE
    Due to the complexity and increasing challenges faced in today’s power system because of the increasing demand in electrical energy, integration of renewable energies and other distributed energy resources, highly responsive and more reliable tools granting outstanding system observability are required. However, the recent advances in control, sensing, computation, and satellite communication technologies, the use of the global positioning system (GPS) providing users with positioning, navigation, and timing (PNT) services, as well as the development of time-stamped measurement technology (SMT), are enormously contributing in making the real-time system monitoring possible. In addition, the recently developed phasor measurement units (PMU) which can provide 30 to 120 timetagged measurements per second increases the proper system observability. This work explores and reviews the synchrophasor technology and the trend of its applications in power system protection and their contribution in bridging the existing gap in protection, control, and monitoring of the Power system.