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Jan T. Bialasiewicz - IEEE Xplore Author Profile

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Cyber-Physical Systems (CPS) require tools that enable development of design methodology that supports analysis and modeling of Interaction Dynamics of Concurrent Processes (IDCP) represented by the measurement data provided by smart acquisition systems. In this paper, are presented some results of the project aiming at the development of algorithms and software tools that could detect short-lived...Show More
In this paper, we present a new approach to evaluation of signal integrity that is based on signal energy density as a function of time and frequency, represented by its wavelet scalogram. Using signal integrity ratio and cumulative energy ratio, we illustrate signal integrity analysis with simulated examples, followed by the demonstration of their usefulness through analysis of experimental data ...Show More
This paper presents an approach to radio frequency (RF) power control along a power curve specified as a function of load impedance, which varies with time. The control algorithm was developed to control the output of electrosurgical generator s but can be used in any other application, where for time-varying loads, some specific power, voltage and current limits have to be met. Such generators ma...Show More
This paper presents an approach to radio frequency (RF) power control along a power curve specified as a function of load impedance, which varies with time. The control algorithm was developed to control the output of electro-surgical generators but can be used in any other application, where for time-varying loads, some specific power, voltage and current limits have to be met. The degree to whic...Show More
During the last years, the power quality (PQ) issues have been a subject of major concern. The constraints that must be fulfilled by the voltage wave supplied by utility companies have become more and more exigent. For this reason, the PQ measurement equipment requires new and computational efficient algorithms. This paper explores the application possibilities of continuous wavelet transform (CWT...Show More
A substantial increase of photovoltaic (PV) power generators installations has taken place in recent years, due to the increasing efficiency of solar cells as well as the improvements of manufacturing technology of solar panels. These generators are both grid-connected and stand-alone applications. We present an overview of the essential research results. The paper concentrates on the operation an...Show More
It has been demonstrated that modulating the switching frequency of a power converter is a valuable way for reducing the electromagnetic interference (EMI) due to the switching process. Since we are considering a signal whose frequency content varies with time, wavelets are well suited to analyze the performance of such techniques. In this paper, we evaluate the performance of spread spectrum freq...Show More
The paper presents a comparative study of a renewable energy system using simulation data versus the data recorded for its implementation at the Hybrid Power System Test Bed (HPSTB) at the National Wind Technology Center, NREL. The simulation data were obtained from the model realized using RPM-SIM simulator. This study shows that under different conditions the power, voltage, and frequency traces...Show More
The use of wind power generation is increasingly being pursued as a supplement and an alternative to large conventional central power stations. The specification of the power electronics interface is subject to requirements related not only to the renewable energy source itself but also to its effects on power system operation, especially where the intermittent energy source constitutes a signific...Show More
This paper explores the effects of wind farm power fluctuations on the power network. A dynamic simulation of a wind farm is performed and the spatial distribution of the wind turbines is considered. In a wind farm, many wind turbines feed power into the power grid at the point of common coupling. The power fluctuation from one turbine may cancel that of another, which effectively rectifies the po...Show More
Renewable-energy systems that are under development need a simulation-based analysis to ensure system stability, power quality, and reliability. Such an analysis may reveal design modifications that need to be made before the system is implemented in the field. The modular simulator RPM-SIM, available on the National Renewable Energy Laboratory Web site (http://wind.nrel.gov/designcodes/simulators...Show More
The use of distributed energy resources is increasingly being pursued as a supplement and an alternative to large conventional central power stations. The specification of a power-electronic interface is subject to requirements related not only to the renewable energy source itself but also to its effects on the power-system operation, especially where the intermittent energy source constitutes a ...Show More
It has been demonstrated that modulating the switching frequency of a power converter is a worthy way to reduce EMI due to switching process. Since modulations following periodic patterns are time dependent processes, wavelets are well suited to analyze the performance of such techniques. Wavelet analysis shows the frequency content of the switching waveform as a function of time that cannot be se...Show More
We analyzed a wind-turbine water-pumping system, which consists of a wind turbine with a permanent magnet generator electrically coupled with a water pump via a motor-generator configuration. Following system's steady-state analysis, we discuss how the success of the start-up process depends on the system's start-up dynamics as related to a proper choice of water pump characteristics. We studied t...Show More
We investigated a small isolated hybrid power system that used two types of power generation; wind turbine and diesel generation. The interaction of diesel generation, the wind turbine, and the local load is complicated because both the load and the wind turbine fluctuate during the day. These fluctuations create imbalances in power distribution (energy sources are not equal to energy sinks) that ...Show More
In this paper, we analyze the steady-state performance and the impact on the power system of the dynamics of small wind turbines with power regulation based on furling control. Using an example of battery charging wind turbine system, we develop its model. In this model, we introduce damping as a component of the restraining moment. This is a novel concept that is not used in the current wind turb...Show More
This paper describes the inclusion of a photovoltaic panel or PV array in the simulation of power systems that use renewable energy sources. It appears as a part of the PV array-inverter assembly that uses the inverter to perform DC to AC energy conversion. In an isolated operation, the inverter dictates the frequency and regulates the output voltage of the system. In addition, it balances the pow...Show More
This paper describes the inclusion of an inverter in the simulation of power systems that use renewable energy sources. The emphasis is on the implementation (in the RPM-SIM simulator) of a variable structure control strategy that switches the master function of controlling voltage and frequency between the diesel generator and the inverter. A case study illustrates the simulator's performance and...Show More
This paper describes the inclusion of a power converter in the simulation of power systems that use renewable energy sources. This paper presents two major roles of the power converter. In an interconnected grid, a power converter can be utilized as a reactive power compensator or an active filter. With a battery on the DC bus, the power converter can function as an energy buffer that stores energ...Show More
We analyzed a wind-turbine water-pumping system, which consists of a wind turbine with a permanent magnet generator electrically coupled with a water pump via a motor-generator configuration. Beginning with a short summary of the system's steady-state analysis, we show how the success of the start-up process and how the system's performance depends on the proper choice of water pump characteristic...Show More
We present a modular simulation system developed to study the dynamics and to aid in the design of hybrid power systems with diesel and wind turbine generation. The emphasis is placed on the representation of the dynamics of the elements of a real system and on the control aspects of the modules. Each module represents a component of the hybrid power system such as the diesel generator, wind turbi...Show More
A new approach to the long-range predictive control, named identified predictive control (IPC), is proposed. The process predictor model, used to determine the control sequence, is derived from a state space formulation of the ARIMAX model and is directly identified using current input-output sequences. Since IPC uses a properly defined observer model of the minimum-variance j-step-ahead predictor...Show More
Originally, adaptive control theory was developed for the ideal system models, i.e., linear system models under the assumption that relative degree and upper bounds on the order of the systems are known. In the early 1980s, adaptive control algorithms designed for such ideal system models were strongly attacked by many researchers due to "lack of robustness" in the presence of unmodeled dynamics a...Show More
Originally adaptive control theory was developed for the ideal system models, i.e., linear system models under the assumption that relative degree and upper bounds on the order of the systems are known. At the beginning of the last decade, adaptive control algorithms designed for such ideal system models were strongly attacked by many researchers due to "lack of robustness" in the presence of unmo...Show More
A Volterra series approach has been applied to the identification of nonlinear systems which are described by a neural network model. A procedure is outlined by which a mathematical model can be developed from experimental data obtained from the network structure. Applications of the results to control of robotic systems are discussed.<>Show More