Murat Gol

• PhD
• Professor (Associate) at Middle East Technical University

In today’s power system where the share of renewables is rapidly increasing, the system now exhibits a more dynamic behavior compared to the past. Therefore, the importance of dynamic simulations at every level of the power system is crucial for the system operators. However, calibration of model parameters and their regular controlling are require...

Incorrect parameters in a power plant dynamic model affect the analysis results and control decisions in a power system, which may have serious consequences. The online calibration techniques in the literature utilize sensitivity analysis to determine the identifiable parameters before the calibration, and treat the majority of sensitive parameters...

Distributed renewable generation can be harmonized with the utility grid in flexible structures called microgrids. However, the use of renewables has its drawbacks, such as intermittency and generation uncertainty. Smart controllers can be used to solve such problems and operate the microgrids seamlessly. Accurate forecasts of the generation and de...

Because of the lack of a proper real-time monitoring system at distribution power networks, topology identification can not be performed properly. While in traditional radial structures the topology is unique, in the presence of an open-ring structure, this issue constitutes a risk for the operation of the system, and the safety of the field staff...

Utilization of plug-in electric vehicle (PEV) load models can improve the performance of smart charging strategies, which increase the reliability of the grid by harnessing the flexibility of PEV loads. This paper presents a method for utilizing personal PEV load models in real-time stochastic charging control with single and finite system-time hor...

Considering the increase in power system size and the number of PMUs, the utilization of a computationally efficient yet accurate static state estimator is crucial. The fast-decoupled WLS estimator (FD-WLS) is the most common method employed in industrial applications, thanks to its computational efficiency and ease of implementation. However, it i...

A good quality stability model is a key factor for accurate power system operations. Inaccurate parameters of the stability models affect the decision making which paves the way for serious consequences. Thus, it is necessary to calibrate the stability model parameters in a regular manner. There are several calibration methods in the literature whi...

The necessity for the utilization of microgrids emerges from the integration of distributed energy resources, electric vehicles, and battery storage systems into the conventional grid structure. In order to achieve a proper operation of the microgrid, the presence of a microgrid control system is crucial. The IEEE 2030.7 standard defines the microg...

Experts in data analytics and power engineering present techniques addressing the needs of modern power systems, covering theory and applications related to power system reliability, efficiency, and security. With topics spanning large-scale and distributed optimization, statistical learning, big data analytics, graph theory, and game theory, this...

Vast and unauthorized penetration of the photovoltaic systems in distribution systems imposed inadequate monitoring challenge to system operators. Although the installation of required monitoring infrastructure does seem as a solution, due to the high installation cost, it is not considered a feasible one, at least for the near future. As an altern...

Rapid increase in the number of photo voltaic systems (PVSs) across the low voltage distribution systems requires real-time monitoring of those systems. However, considering the necessary investment cost, real-time monitoring infrastructure installation does not seem to be achieved in the near future. Thus, alternative approaches to achieve this ne...

Generated power of a solar panel is volatile and susceptible to environmental conditions. In this study, we have analyzed variables affecting the generated power of a 17.5 kW real-world solar power plant with respect to five independent variables over the generated power: irradiance, time of measurement, panel’s temperature, ambient temperature and...

Microgrids are composed of distributed energy resources (DERs), storage devices, electric vehicles, flexible loads and so on. They may either operate connected to the main electricity grid (on-grid operation) or separated from the grid (islanded operation). The outputs of the renewable energy sources may fluctuate and thus can cause deviations in t...

The objective of this study is to propose a dynamic generator maintenance scheduling (GMS) algorithm for long‐term power sector forecasting and planning studies in which electricity price and the resulting supply composition are determined with merit‐order dispatch. Compatible with the GMS algorithm, a reasonable strategy for the utilisation of sto...

The increasing number of distributed energy resources (DERs), advancing communication and computation technologies, and reliability concerns of the customers have caused an intense interest in the concept of microgrid. Although DERs are the biggest motivation of the microgrids due to their intermittent generation characteristics, they constitute a...

Rapid increase in the number of photo voltaic systems (PVSs) across the low voltage distribution systems required real-time monitoring of those systems. However, considering the necessary investment cost, real-time monitoring infrastructure installation does not seem to be achieved in the near future. Thus, alternative approaches to achieve this ne...

Electric power network expanded rapidly in recent decades due of the excessive need of electricity in every aspect of life, including critical infrastructures such as medical services, and transportation and communication systems. Natural disasters are one of the major reasons of electricity outage. It is extremely important to restore electrical e...

As the society becomes more dependent on the presence of electricity, the resilience of the power systems gains more importance. This paper develops a decision support method for distribution system operators to restore electricity after an earthquake to the maximum number of customers in the minimum expected duration. The proposed method employs M...

Power system resiliency and robustness became major concerns of the system operators and researchers after the introduction of the smart grid concept. The improvements in the battery storage systems (BSS) and the photovoltaic (PV) systems encourage power systems operators to enable the use of those systems in resiliency and robustness studies. Util...

Today, with the development of electrical storage system technologies, these units have come to dimensions that can be used in houses. In this report, effect of energy storage systems on electrical system will be examined both on the basis of the system operators and on the basis of consumer. At the same time, control of electrical storage systems...

In deregulated market environments, transmission system expansion planning becomes a troublesome task as transmission system operators lose their direct control over plant investments. Moreover, the increase in the share of renewable sources in electricity generation creates an uncertainty about future generation investments in terms of location an...

This work proposes an electricity price forecasting model of Turkish Electricity Market for medium-term studies by means of supply and demand dynamics formed via a theoretical approach. The electricity market model created within this scope consists of three main components such as electricity demand forecasting model, electricity supply forecastin...

Hybrid state estimation determines the states of systems monitored both by conventional SCADA measurements and PMUs. This paper proposes a decentralization method in order to improve the computational performance of hybrid state estimators with minimum loss of accuracy. The proposed method utilizes sensitivity matrix that relates measurement errors...

This paper proposes an optimal Phasor Measurement Unit (PMU) placement method based on a modified version of the well-known binary integer linear programming formulation, which will utilize the installed PMUs and conventional measurements, i.e. active and reactive power flow and power injection measurements, to reduce the number of PMUs to be place...

In this paper, a state-estimation-based method is proposed to determine harmonic current contributions of iron and steel (I&S) plants supplied from a point of common coupling (PCC). Due to highly nonlinear nature of the I&S plant operation, accurate estimation of harmonic contributions of the individual plants is essential. In the proposed method,...

In this paper, a state estimation based method is proposed to determine harmonic current contributions of iron and steel (I&S) plants supplied from a Point of Common Coupling (PCC). Due to highly nonlinear nature of the iron and steel plant operation, accurate estimation of the harmonic contributions of the individual plants is essential. In the pr...

Given the rapid increase in the number of phasor measurement units (PMU) installed in substations in recent years, it is not unrealistic to assume that most transmission systems will be fully observable by only PMU measurements in the not so distant future. Such a scenario will enable faster and numerically easier state estimation solution which wi...

In this paper, a state estimation based method is proposed to determine harmonic current contributions of plants supplied from a Point of Common Coupling (PCC). By using Weighted Least Squares (WLS) state estimation, it is aimed to improve harmonic voltage measurements acquired from conventional voltage transformers, which are employed commonly in...

Current state estimators employ the Weighted Least Squares (WLS) estimator to solve the state estimation problem. Once the state estimates are obtained, Chi-Square test is commonly used to detect the presence of bad data in the measurement sets. Regretfully, this test is not entirely reliable, that is, bad data existing in the measurement set could...

This paper is concerned about effective incorporation of a limited number of phasor measurement unit (PMU) measurements into the state estimation solution in order to enhance the state tracking accuracy and speed. This is particularly important for fast changing system conditions when rapid control action may be necessary based on the onset of volt...

Given a sufficient number of properly placed synchronized voltage and current phasor measurements, an L1 estimator (also known as the Least Absolute Value or LAV estimator) can be shown to be robust against gross measurement errors. This paper is concerned about the placement of phasor measurement units (PMU) in order to establish a desired level o...

Power systems do not always operate under fully balanced conditions because of unbalanced loads and untransposed transmission lines. Under such conditions, commonly used positive sequence equivalent will no longer be valid. On the other hand, use of full three-phase model will add significant computational burden for the considered application. Thi...

The weighted least squares (WLS) estimator is commonly employed to solve the state estimation problem in today's power systems, which are primarily measured by SCADA measurements, including bus power injection, branch power flow and bus voltage magnitude measurements. Despite being widely used, WLS estimator remains to be non-robust, i.e., it fails...

State estimation has a key role in secure operation of power systems and management of power markets. It calculates the optimal estimates of the system states using the available measurements. Increasing number of phasor measurement units (PMU) installed in power systems motivated their integration also into state estimators which so far relied sol...

Least Absolute Value (LAV) estimators that are based solely on phasor measurements are known to be robust against bad data provided that there is enough redundancy in the measurement set. This paper investigates the required level of redundancy and develops a systematic approach to place Phasor Measurement Units (PMU). The optimal placement will be...

This paper proposes observability and measurement criticality analysis methods for any type of current phasor measurement configurations. Measurement Jacobian cannot be decoupled when using current phasor measurements and thus conventional methods of network observability analysis can no longer be used. Current phasor measurements may be classified...

State estimation has an important role in the operation of power systems and associated power markets. It is well known that state estimators are vulnerable to any existing critical measurements since their errors cannot be detected. Therefore, by manipulating a finite number of critical measurements, a hacker can bias the results of state estimati...

Power systems may not always operate under fully balanced conditions due to unbalanced loads. Such cases will necessitate full three-phase monitoring of the system state. Thus, positive sequence network model and associated state estimation formulation will not be valid for such operating conditions. It is clearly possible to use a simple extension...

Power system state estimators (ses) have come a long way since the introduction of the concept nearly four decades ago by Fred Schweppe. Over the years, the concept's initial formulation, implementation techniques, computational requirements, data manipulation and storage capabilities, and measurement types have changed significantly. Today, SEs ar...

State estimation problem is commonly solved by the weighted least squares (WLS) method, which is known to be non-robust, i.e. it fails in the presence of a single bad measurement. A more robust alternative is the least absolute value (LAV) estimator which can automatically reject bad-data in the absence of the so called leverage measurements. When...

Classical observability analysis methods that are based on decoupled network equations cannot be directly applied to systems containing voltage and current phasor measurements, since the equations can no longer be decoupled when current phasor measurements are present. Moreover, conventional voltage magnitude measurements are commonly disregarded i...

Classical observability analysis and critical measurement detection methods cannot be applied to the Phasor Measurement Units (PMUs), since Jacobian matrix of current phasor measurements cannot be decoupled as in the case of power measurements. This paper proposes a method to investigate the observability and criticality of PMUs.

A new electric arc furnace (EAF)-specific model based on field measurements of instantaneous furnace voltages and currents has been proposed. This model presents the dynamic behavior of the EAF system, including all parts, i.e., the EAF transformer, the secondary circuit, the electrode movements, and the arc. It consists of a cascade connected vari...