Mudrov, M., A. Ziuzev, K. Nesterov, and S. Valtchev,
"Asynchronous electric drive power-hardware-in-the-loop system",
Proceedings - 2018 17th International Ural Conference on AC Electric Drives, ACED 2018, vol. 2018-April, United States, Institute of Electrical and Electronics Engineers Inc., pp. 1–5, 4, 2018.
AbstractPower Hardware-in-the-Loop (PHiL) system for asynchronous electric drives application based on power inverter with Field Programmable Gate Array (FPGA)-based control system is discussed. Proposed PHiL structure and scheme for asynchronous electric drives are under discussion as well. Described PHiL can be used for power inverters multi-stage testing.
Valtchev, S., R. Miletiev, R. Arnaoudov, and S. Valtchev,
"Control strategy for efficient operation of super-resonant SLSR (contactless) converters",
XLIV INTERNATIONAL SCIENTIFIC CONFERENCE ON INFORMATION, COMMUNICATION AND ENERGY SYSTEMS AND TECHNOLOGIES (before 1990 was: "Day of the Radio Conference"), pp. 527–530, June, 2009.
Inácio, D., J. A. Inácio, J. Pina, S. Valtchev, M. Neves, J. Martins, and A. Rodrigues,
"Conventional and HTS Disc motor with pole variation control",
2nd International Conference on Power Engineering, Energy and Electrical Drives (POWERENG'2009), pp. 513–518, 2009.
AbstractIn this paper, a poly-phase disc motor innovative feeding and control strategy, based on a variable poles approach, and its application to a high temperature superconductor (HTS) disc motor, are presented. The stator windings may be electronically commutated to implement a 2, 4, 6 or 8 poles winding, thus changing the motor's torque?speed characteristics. The motor may be a conventional induction motor with a conductive disc rotor, or a new HTS disc motor, with conventional copper windings at its two iron semi-stators and a HTS disc as a rotor. The conventional induction motor's operation principle is related with the induced electromotive forces in the conductive rotor. Its behaviour, characteristics and modelling through Steinmetz and others theories are well known. The operation principle of the motor with HTS rotor, however, is rather different and is related with vortices' dynamics and pinning characteristics; this is a much more complex process than induction, and its modelling is quite complicated. In this paper, the operation was simulated through finite-elements commercial software (FLUX2D), whereas superconductivity was simulated by the E-J power law. The electromechanical performance of both motor's computed are compared. Considerations about the systems overall efficiency, including cryogenics, are also discussed.
Mihaylov, K., R. Arnaudov, and S. Valtchev,
"Design and analysis of wireless sensor network powered through neutral to earth voltage",
Proceedings - 2018 17th International Ural Conference on AC Electric Drives, ACED 2018, vol. 2018-April, United States, Institute of Electrical and Electronics Engineers Inc., pp. 1–6, 4, 2018.
AbstractA low power wireless sensor network utilizing the neutral to earth voltage as a power source is developed and analyzed. It consists of a batteryless energy harvesting powered wireless sensor nodes, a gateway (if needed) and a local or remote server (if used). An invasive energy harvesting method to use the voltage between the neutral conductor and the ground conductor is used for the sensor module. A test network is built in a household. Statistics of the household's electric current and the corresponding neutral conductor's voltage is obtained during a two months period. The statistics is further processed to verify the working principle of the proposed network and to enlighten its strengths and weaknesses. The sensor nodes are developed using widely existing electronic components and don't require specialized devices.
Mesherayakov, V., V. Voekov, V. Ivashkin, and S. Valtchev,
"Designing the universal vector control system with relay current regulator principle for general purpose industrial AC motor drive control",
12th International Scientific and Practical Conference “Modern Complex Control Systems 2017”, Proceedings, vol. 2: Russian Academy of Sciences, pp. 320–330, 2017.
Abstractn/a
Belousov, {A. S. }, {V. N. } Meshcheryakov, S. Valtchev, and {O. V. } Kryukov,
"Development of a Control Algorithm for Three-Phase Inverter in Two-Phase Electric Drives Reducing the Number of Commutations",
Proceedings - 2019 1st International Conference on Control Systems, Mathematical Modelling, Automation and Energy Efficiency, SUMMA 2019, United States, Institute of Electrical and Electronics Engineers Inc., pp. 444–449, 11, 2019.
AbstractImportant requirements for the modern electric drives are the high overload capacity and a wide range of speed control. A two-phase adjustable low-power drive has these properties, but its implementation in small-scale mechanics is hindered by the need a frequency converter that provides a three-phase power grid into a two-phase network, which is important when the power of the mechanisms increases. Previous studies have already shown the possibility of using a typical frequency converter based on a three-phase full-bridge voltage inverter applying space-vector PWM method. The switching frequency of the inverter remains, unfortunately, relatively high. It is not possible to reduce this frequency without degrading the harmonic composition. The goal of this work is to develop an algorithm for controlling the two-phase electric drive system, while reducing the numberof commutations of the switching devices of the three-phase inverter, and at the same time keeping the deviations of the instantaneous values of the phase currents close enough to the reference.
Mudrov, M., A. Ziuzev, K. Nesterov, and S. Valtchev,
"Electric Drives Power-Hardware-in-the-Loop System Structures",
2018 20th European Conference on Power Electronics and Applications, EPE 2018 ECCE Europe, United States, Institute of Electrical and Electronics Engineers Inc., 10, 2018.
AbstractPower-Hardware-in-the-Loop (PHiL) system for electric drives application based on power converter with Field Programmable Gate Array (FPGA)-based control system is discussed. PHiL structures are under discussion as well. During the PHiL mathematical model analysis instantaneous current repeating quality is increased. Variable frequency drive (VFD) was selected for testing.
Romba, {L. F. }, {S. S. } Valtchev, R. Melicio, {M. V. } Mudrov, and {A. M. } Ziuzev,
"Electric vehicle battery charger controlled by magnetic core reactor to Wireless Power Transfer system",
Conference Proceedings - 2017 17th IEEE International Conference on Environment and Electrical Engineering and 2017 1st IEEE Industrial and Commercial Power Systems Europe, EEEIC / I and CPS Europe 2017, United States, Institute of Electrical and Electronics Engineers Inc., 2017.
AbstractThis paper presents a control process and frequency adjustment based on the Magnetic Core Reactor prototype. For the past decades, there has been significant development in the technologies used in Wireless Power Transfer systems. In the Wireless Power Transfer systems it is essential that the operating frequency of the primary circuit be equal to the resonant frequency of the secondary circuit so there is the maximum energy transfer. The Magnetic Core Reactor allows controlling of the frequencies on both sides of the transmission and reception circuits. In addition, the assembly diagrams and test results are presented.
Baikova, {E. N. }, {L. F. } Romba, S. Valtchev, R. Melício, and V. {Fernão Pires},
"Electromagnetic Emissions from Wireless Power Transfer System",
CETC2016 - Conference on Electronics, Telecommunications and Computers, Proceedings: ISEL - Instituto Superior de Engenharia de Lisboa, 2016.
Abstractn/a
Mudrov, M., A. Zyuzev, K. Nesterov, and S. Valtchev,
"FPGA-based Hardware-in-the-Loop system bits capacity evaluation based on induction motor model",
Conference Proceedings - 2017 17th IEEE International Conference on Environment and Electrical Engineering and 2017 1st IEEE Industrial and Commercial Power Systems Europe, EEEIC / I and CPS Europe 2017, United States, Institute of Electrical and Electronics Engineers Inc., 7, 2017.
AbstractThe Hardware-in-the-Loop (HiL) systems become nowadays popular. In the same time, the Field Programmable Gate Arrays (FPGAs) allow for creating the HiL with time step 1 μs or less. The FPGA usually executes the numerical operations on Fixed Point variables. That is why during the FPGA-based HiL creation process it is important to select a proper number of bits for the modeled variables. A mathematical model based on the induction motor is selected as a basis for comparative tests between the floating point model and the fixed point model. In consequence, recommendations for the Bit Capacity (the length of the digital word) selection are given, based on the obtained results.
Mudrov, M., A. Zyuzev, N. Konstantin, S. Valtchev, and S. Valtchev,
"Hardware-in-The-loop system numerical methods evaluation based on brush DC-motor model",
Proceedings - 2017 International Conference on Optimization of Electrical and Electronic Equipment, OPTIM 2017 and 2017 Intl Aegean Conference on Electrical Machines and Power Electronics, ACEMP 2017, United States, Institute of Electrical and Electronics Engineers Inc., pp. 428–433, 7, 2017.
AbstractHardware-in-The-loop (HiL) systems nowadays become popular. During the HiL creation process it is important to select a proper numerical method because the accuracy of the process simulation, in case of the HiL, depends on the correct numerical approach selection. That is why it is important to evaluate the most popular numerical approaches. The {"}Sequential{"} Euler (solves equations step-by-step), the Forward Euler (the most popular method for HiL creators), and the Second-order Adams-Bashforth approach are under consideration. A mathematical model based on the DC-motor with independent excitation is selected as a basis for the experimental numerical calculation. In consequence, recommendations for the numerical method selection are given, based on the obtained results.
Ferreira, S., S. Valtchev, F. Coito, and M. Mudrov,
"Mechanical vibration using piezoelectric material",
Proceedings - 2017 International Conference on Optimization of Electrical and Electronic Equipment, OPTIM 2017 and 2017 Intl Aegean Conference on Electrical Machines and Power Electronics, ACEMP 2017, United States, Institute of Electrical and Electronics Engineers Inc., pp. 681–686, 7, 2017.
AbstractPiezoelectric energy harvesting has received great attention over the last 20 years. The main goal of this work is to discuss the potential advantages of introducing non-linearities in the dynamics of a beam type piezoelectric vibration energy harvester. The described device is essentially a cantilever beam partially covered by piezoelectric material with a force electromagnetically applied to the beam. Through experimental tests it has been confirmed the benefits of introducing non-linearities in these types of systems.
Braslavsky, {I. Y. }, {V. P. } Metelkov, {A. V. } Kostylev, and S. Valtchev,
"On reliability and energy efficiency increasing of the vehicles electric drives",
Proceedings - 2018 17th International Ural Conference on AC Electric Drives, ACED 2018, vol. 2018-April, United States, Institute of Electrical and Electronics Engineers Inc., pp. 1–6, 4, 2018.
AbstractProblem of the reliability increasing of the vehicles electric drives is discussed in context of the reduction of the electric motor heating during variable character of movement. Opportunities of the induction motor stator winding heating reduction by means of the control of the vehicles electric drives in transient and steady state modes of movement are shown. Analytical expressions for dynamic torque, optimal on minimal of the winding temperature rise during acceleration, as well as expressions for dynamic torque and value of the motor torque limitation, optimal on energy consumption during acceleration are presented. It is shown that desire to reduce the stator winding temperature rise by means of dynamic torque optimal value selection or motor torque limitation can lead to the rise of energy consumption. Results of the modeling are presented.
Mudrov, M., A. Ziuzev, K. Nesterov, and S. Valtchev,
"Power electrical drive Power-Hardware-in-the-Loop system: 2018 X International Conference on Electrical Power Drive Systems (ICEPDS)",
2018 10th International Conference on Electrical Power Drive Systems, ICEPDS 2018 - Conference Proceedings, United States, Institute of Electrical and Electronics Engineers Inc., 12, 2018.
AbstractPower Hardware-in-the-Loop (PHiL) system for electric drives application based on power converter with Field Programmable Gate Array (FPGA) -based control system which realizes in real time model of converter, motor and mechanism is discussed. Two PHiL structures are under consideration. Difference between both of them is shown. Test results obtained in the PHiLs with Converter Under Test (CUT) control system are presented in the paper. Proposed PHIL is intended for converters testing and for their operating modes studying. The PHIL repeats electric drive instantaneous current and angular velocity.
Baikova, {E. N. }, L. Romba, R. Melicio, and {S. S. } Valtchev,
"Simulation and experiment on electric field emissions generated by wireless energy transfer",
Technological Innovation for Resilient Systems - 9th IFIP WG 5.5/SOCOLNET Advanced Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2018, Proceedings: Springer New York LLC, pp. 243–251, 1, 2018.
AbstractThis paper presents a wireless energy transfer (WET) system operating at the frequency of tens of kHz. It treats the modeling and simulation of WET prototype and its comparison with experimental measuring results. The wireless energy transfer system model was created to simulate the electric field between the emitting and the receiving coils, applying the finite element method. The results from the simulation are compared to the measured values of the electric field emission from the wireless energy transfer equipment. In the recent years the interest in the WET technology, especially for the electric vehicles (EV) batteries charging, is rapidly growing. The WET systems pollute the environment by electromagnetic emissions. Due to the expanding use of this technology in industrial and consumer electronics products, the problems associated with the electromagnetic compatibility (EMC), and the adverse impact on the human health becomes highly important.
Romba, L., {S. S. } Valtchev, and R. Melício,
"Single-phase wireless power transfer system controlled by magnetic core reactors at transmitter and receiver",
Technological Innovation for Smart Systems - 8th IFIP WG 5.5/SOCOLNET Advanced Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2017, Proceedings: Springer New York LLC, pp. 419–428, 2017.
AbstractThe applications of wireless power transmission have become widely increasing over the last decade, mainly in the battery charging systems for electric vehicles. This paper focuses on the single-phase wireless power transfer prototype controlled by magnetic core reactors in either side of the system: that of the transmitter, and that of the receiver. The described wireless power transfer system prototype employs a strong magnetic coupling technology to improve the power transmission efficiency. In the same time, a magnetic core reactor is used to control the “tuning” between the transmitter and the receiver frequencies, allowing for that increase of the system efficiency. Finally, practical results of the implemented prototype are presented.
Romba, L., {E. N. } Baikova, C. Borges, R. Melicio, and {S. S. } Valtchev,
"Wireless battery charger for EV with circular or planar coils: comparison",
Technological Innovation for Resilient Systems - 9th IFIP WG 5.5/SOCOLNET Advanced Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2018, Proceedings: Springer New York LLC, pp. 214–223, 1, 2018.
AbstractThis paper presents the experimental results obtained in the wireless energy transfer (WET) system prototype based on coils: circular or planar. With these experimental results we can choose the tuning settings to improve the efficiency of power transmission of the WET systems. In WET for electric vehicle batteries charging, the coil shape and the range between the coils are the most important issues of those systems.