Jan Michalik

Single-phase current-source active rectifier for traction applications: new control strategy based on phase shift controller

This research has been motivated by industrial demand for single-phase current-source active rectifier (CSAR) dedicated for reconstruction of older types of dc machine locomotives operating on both ac catenary voltages of 25 kV/50 Hz and 15 kV/16 2/3 Hz. This contribution presents new control strategy of CSAR using controller of phase shift angle (phi) between trolley wire voltage and current. Regarding possible interaction with railway control signalling and due to the low switching frequency, the designed converter employs synchronous PWM. This paper describes in detail proposed converter control and presents simulation results of the laboratory prototype. The simulation results and theoretical conclusions are verified by experiments performed on designed low power laboratory prototype of traction CSAR with rated power of 7 kVA.

Control of traction single-phase current-source active rectifier under distorted power supply voltage

This research has been motivated by industrial demand for single-phase current-source active rectifier (CSAR) dedicated for reconstruction of older types of dc machine locomotives. This contribution presents new control strategy of CSAR using controller of phase shift angle (phi) between trolley wire voltage and current supplemented by compensation of trolley wire current waveform under supply voltage distortion. This control is able to keep the trolley wire current in demanded phase shift against supply voltage and preserve sinusoidal waveform of consumed current even under distorted trolley wire voltage. Simulation results and theoretical conclusions are verified on designed laboratory prototype of 7 kVA.

Control of primary voltage source active rectifiers for traction converter with medium-frequency transformer

This paper deals with the new configuration of the traction converter with medium-frequency transformer intended for AC trolley wire fed locomotives. The main attention is paid to the primary serially connected single-phase voltage-source active rectifiers, which are directly connected to the trolley wire. This paper describes the control of the primary active rectifiers, presents simulation results as well as experimental evidence of designed low-voltage laboratory prototype of loco converter of rated power of 12 kW.

Single-Phase Current-Source Active Rectifier for Traction Applications: New Control Strategy Based on Phase Shift Controller

Abstract This paper deals with the single-phase current-source active rectifier dedicated for reconstruction of older types of d.c. machine locomotives operating on both a.c. trolley wire voltages of 25 kV/50 Hz and 15 kV/16 2/3 Hz. This contribution presents new control strategy of the current-source active rectifier using controller of phase shift angle (φ) between the trolley wire voltage and current. Regarding possible interaction with railway track circuits and due to the low switching frequency, the converter employs synchronous PWM. This paper describes in detail proposed converter control and presents simulation results of the laboratory prototype. The simulation results and theoretical conclusions are verified by experiments performed on designed low voltage laboratory prototype of traction current-source active rectifier of rated power of 7 kVA.

Variable speed pumping in thermal and nuclear power plants: Frequency converter versus hydrodynamic coupling

In this paper, a comprehensive case study analysis of flow control methods and appropriate technical implementations for high-power pump systems employed in thermal and nuclear power plants or heating plants will be presented. The main attention is focused on a comparison of two advanced variable speed control strategies employing VSD with frequency converter and VSD with hydrodynamic coupling.

Sophisticated software for design and optimization of VSDs for high-power pumps: Variable speed drive with frequency converter

This paper deals with a developed software for design and optimization of variable speed drives (VSDs) for high-power water pumps and fans in power and heating plants. The paper presents the physical background of modeling and proposed models of a variable speed drive with frequency converter.

Active suppression of low-frequency disturbances on AC side of traction active current-source rectifier

This paper deals with traction active current-source rectifier (ACSR) developed within the research into a new generation of main traction converters employing medium-frequency transformer dedicated for suburban units operating on both ac electrification systems of 25kV/50 Hz and 15kV/16⅔ Hz. The new control strategy able to operate under distorted trolley-wire voltage and actively suppress (i) low-frequency disturbances in trolley-wire current caused by distorted trolley-wire voltage, and (ii) input LC filter oscillations is presented. Proper function of proposed control strategy has been verified by simulations and large experimental study made on designed small-scale prototype of ACSR of rated power of 7kVA.

Design of control system for forced dynamics control of an electric drive employing linear permanent magnet synchronous motor

The paper presents forced dynamics control of an electric drive with linear permanent magnet synchronous motor. This control method offers an accurate realisation of a dynamic speed response, which can be selected for given application by the user. In addition to this, the angle between stator current vector and moving part flux vector are maintained mutually perpendicular as it is in conventional vector control. To achieve prescribed speed response derived control law requires an external force information, which is obtained from the set of observers. The first set of observers is based on sliding-mode, while the second observer is classical full-state observer and exploits information of the position sensor. Simulations of the overall control system together with preliminary experimental results for the drive with rotational synchronous motor predict intended performance of the drive

Sophisticated software for design and optimization of variable speed drives for high-power pumps: Hydrodynamic coupling versus frequency converter

This paper deals with an analysis and comparison of high-power pump systems with flow control based on variable speed drives (VSDs). The attention is focused on a comparison of two advanced variable speed control strategies employing VSD with frequency converter and VSD with hydrodynamic coupling. Due to a very different nature of both drives it is a challenging task to compare them to each other, especially, in the area where a tiny efficiency improvement causes substantial energy consumption and/or CO2 emission reduction. The paper presents comparison of both VSDs in typical fields of their application (power plant, heating plant) in the form of case study. The calculations were performed using the software which we have developed for design, optimization and sophisticated comparison of these drives. Description of physical background of modeling and proposed models is also included.

Single-phase current-source active rectifier: New approach in active suppression of low-frequency disturbances on converter AC side

This paper deals with a single-phase active current-source rectifier (ACSR) developed within the research into a new generation of main traction converters employing medium-frequency transformer dedicated for suburban units operating on both ac electrification systems of 25kV/50 Hz and 15kV/16, 7 Hz. The new approach in active suppression of low-frequency disturbances in trolley-wire current using resonant (R) controllers is presented. Proper function of proposed control strategy with a new compensative principle has been verified by simulations and large experimental study made on designed small-scale prototype of ACSR of rated power of 7kVA.