Power Semiconductor Converter Research Articles

Analysis and improvement of power quality in the onboard electrical power systems within a self-propelled floating crane

This research addresses electromagnetic compatibility and power quality (EMC and PQ) challenges in shipboard electric power systems (SEPS) with dynamic positioning (DP) capabilities, focusing on the self-propelled floating crane (SPFC) “EXPERT 3.” Our goal is to enhance methodologies for evaluating power quality indicators (PQI) related to voltage and current waveform distortions, specifically in converter-based propulsion complexes (CBPCs) featuring variable-frequency regulated asynchronous drives (VFDs). We investigate harmonic current and voltage distortions, reactive power generation, and power factor (PF) in SEPS “EXPERT 3″ during the operation of VFDs with conventional semiconductor power converters (SPCs). A refined MATLAB model considers equipment and cable network parameters, validating distortion indicators at ship synchronous generators (SGs). PQI compliance with international maritime standards is verified at the point of common coupling (PCC) for various VFD configurations with pulse width modulated (PWM) SPCs and filter-compensating devices (FCDs). We propose an improved controlled FCD (CFCD) incorporating a resonance filter (RF) and a controllable reactor compensator (CRC). CFCD efficiency in various VFD configurations is experimentally validated. We analyze harmonic distortions of voltage and current, including high-frequency (HF) commutations in VFDs with input thyristor-based rectifiers (TBRs), considering parasitic ”phase-hull“ capacitances of cable line segments (CLS). Our study examines harmonics in CBPC-based SEPS in two sub-frequency ranges: low-frequency (LF) − 0 to 2 kHz and high-frequency (HF) − 2 kHz to 500 kHz.© 2017 Elsevier Inc. All rights reserved.

Activity of Technical Committee on Semiconductor Power Converter

Activity of Technical Committee on Semiconductor Power Converter

Повышение эффективности электропривода электровоза с управляемым преобразователем возбуждения тяговых двигателей

Purpose: To substantiate the circuit design and algorithms for individual smooth and automatic control of single-phase direct current electric locomotives according to the laws of constant traction force and constant power without breaking the electric locomotive power circuits in order to increase the efficiency of its electric drive with controllable traction motor excitation converters. As a circuit design solution, it is proposed to apply a power electrical circuit with two rectifier-inverter converters for each section of the electric locomotive for bogie-based traction control, as well as individually controlled bridge transistor converters, shunting field windings, for axial traction control within each bogie. Methods: The development of circuit solutions using modern power semiconductor converters; theory of automatic control and design of finite state machines; mathematical modeling of electromagnetic, electromechanical and mechanical processes. Results: The developed control algorithms provide the possibility of obtaining traction characteristics of an electric locomotive that vary according to the laws of constancy of traction force or constancy of power, bringing the traction characteristics of electric locomotives with collector traction motors to the characteristics of electric locomotives with asynchronous traction motors. The calculations performed confirmed the possibility of implementing an algorithm for individual control of traction motor currents and their excitation currents, as well as traction forces, which ensures a smooth increase in the traction force of an electric locomotive.Practical significance: The developed technical solutions applicable in the manufacture of modern and modernization of operated electric locomotives will ensure an increase in the traction properties of singlephase DC electric locomotives and will contribute to an increase in the throughput and carrying capacity of the railway network.

Evaluation of Electric Power Quality in the Ship-Integrated Electrical Power System with a Main DC Bus and Power Semiconductor Electric Drives as Part of the Electric Propulsion Complex

The relevance of the work is connected to the energy efficiency of specialized vessels of the technical fleet. The purpose of the study was to determine and evaluate the power quality indicators associated with the non-sinusoidal shape of the voltage and current curves in the electrical power system of the marine platform support vessel, which contains powerful semiconductor propulsion electric drives, taking into account the inherent and parasitic parameters of the power three-phase cable lines. A simplified one-line diagram of an electric power system with a DC main bus was the object of the study, which was compiled as a result of the analysis of analog systems typical for the indicated type of vessels. The phenomenon of voltage and current distortion caused by the presence of higher harmonics generated by power semiconductor converters in a three-phase ship network was the subject of the research. For the experimental study of the quality of electric power according to the simplified one-line scheme of the electric power system in MATLAB Simulink, its model was created. Based on the proven methods of calculating the ship’s electrical equipment, a methodology was developed for the reliable determination of model parameters. According to the results of the experiment in MATLAB Simulink, qualitative and quantitative indicators were obtained regarding the non-sinusoidality of the linear voltage and current of the three-phase network (curve shapes, amplitude spectra, distortion coefficients), and their comparative analysis with the current norms and standards was performed. In contrast to the previous ones, the methodology for assessing the quality of electricity in the studied electric power system takes into account its circuit, mode features, and the presence of a parasitic capacitance “phase to ground” of a three-phase network, and it can be used in solving similar non-trivial tasks for various similar structurally modified systems.

The Analysis, Modeling, and Control of the Forward DC/DC Converter for the Electric Vehicle

This article deals with the analysis, modeling, and control of the DC/DC converters. Although it is considered with the analysis of the power semiconductor converters in general however it can be applied also to sophisticated electronic devices perfectly suitable for on-board applications of a huge variety of transport vehicles. Specifically, as an example, the Forward type topology is used which offers the advantage of the galvanic isolation of output. The task is to obtain a state space description of the system, the transfer function of the control, and design controller parameters using MATLAB. The state space model and the transfer function is implemented for the ideal and nonideal type of topology, where it is considered with at least some parasitic parameters of circuit elements to get closer to real results of the physical sample and to compare obtained transfer functions based on their frequency characteristics.

Automatic Control System for a Power Semiconductor Converter in Diesel Locomotives with Collector Traction Motors

Automatic Control System for a Power Semiconductor Converter in Diesel Locomotives with Collector Traction Motors

Investigation of the Properties of a Five-Phase Induction Motor in the Introduction of New Fault-Tolerant Control

Multiphase electric motors in cooperation with power semiconductor converters belong to the future of electric drives. This is because of their better properties compared to three-phase motors, such as better fault tolerance. How a multiphase motor will behave in a fault state is very important when using such motors in EV and HEV. This is the basis of the research in this article; we investigate the options for operating a five-phase motor in a fault condition in order to improve the drive qualities during fault operation. The complete mathematical expressions of the five-phase induction motor model in the normal operation as well as in fault operation and also the control modification to improve the properties of the drive are presented. The new five-phase field-oriented control is next described, which improves the drive qualities in four-phase operation and is the first fundamental aspect of the study. Another important aspect of the project is the development of a specific control on a real motor, followed by measurements of properties of a five-phase motor in normal and fault operation of one phase without and with control modification to enhance drive characteristics. The qualities and appropriateness of employing a five-phase motor as a drive in EV and HEV are then determined by comparing these results. Finally, a comparison of motor attributes is shown with and without control adjustment.

Automatic control system of a power semi-conductor converter for diesel locomotives with collector traction motors EVSEEV V.Yu., SAVOS’KIN A.N

Automatic control system of a power semi-conductor converter for diesel locomotives with collector traction motors EVSEEV V.Yu., SAVOS’KIN A.N

Analysis of exact and approximating dependences of active resistance of a conductor on the current frequency based on the influence of skin effect

The operation of semiconductor power converters, which are part of tractionsubstations, frequency-controlled electric drives and other powerful nonlinear loads, cause asignificant emission of higher harmonics of currents to electrical networks. Higher harmonics ofcurrents in electrical networks cause a complex negative effect on the energy efficiency of thenetwork. The increase in power losses in the active resistance under the action of higher harmonicsis due to the increase in the root mean square value of the current and the action of the skin effect.Analytical expressions describing the dependence of the active and impedance of the electricnetwork on the current frequency are determined. Based on them, analytical expressions are obtainedfor the calculation of additional power losses under the action of higher harmonics of currents, whichare due to the skin effect. The dependences of the active resistance of the electric network on thefrequency of higher harmonics are determined on the basis of Bessel equations. The analysis of convergence of the received equations with the data of the international standard IEC 60287-1-1 iscarried out. For the high-frequency zone, simplified approximating dependences are given, whichdetermine the parabolic dependence of the active resistance on the frequency. Simplifiedapproximating dependences of active resistance on the frequency of higher harmonics are obtainedfor engineering calculations. The obtained equations can be used to determine additional powerlosses in the active supports of electrical networks, windings of electric machines, high-frequencytransformers from higher harmonics of currents at different nonlinear loads. In addition, the obtainedexpressions can be used to justify the use of filter-compensating devices.

Energy efficiency of power electronics converters in traction power supply networks at voltage increase

The main features of the procedure for predicting electrical losses in power semiconductor converters of AC-DC and DC-AC systems of high voltage DC traction are presented. The procedure is based on simulation of multi-cycle switching of IGBT modules in combination with simulation of static and dynamic switching losses in traction converter circuits. The models take into account the switching frequency, physical processes in the formation of voltage and current diagrams at transition processes and in the static state of the switch elements. The model of loss assessment using particular types of IGBT modules is the basis for calculating the energy efficiency characteristics of traction converters for advanced high-voltage direct current traction systems.

Current Status and Future Prospects of Marine Semiconductor Power Converters

Current Status and Future Prospects of Marine Semiconductor Power Converters

System Level Simulation of Microgrid Power Electronic Systems

In this paper, we describe a procedure for designing an accurate simulation model using a price-wised linear approach referred to as the power semiconductor converters of a DC microgrid concept. Initially, the selection of topologies of individual power stage blocs are identified. Due to the requirements for verifying the accuracy of the simulation model, physical samples of power converters are realized with a power ratio of 1:10. The focus was on optimization of operational parameters such as real-time behavior (variable waveforms within a time domain), efficiency, and the voltage/current ripples. The approach was compared to real-time operation and efficiency performance was evaluated showing the accuracy and suitability of the presented approach. The results show the potential for developing complex smart grid simulation models, with a high level of accuracy, and thus the possibility to investigate various operational scenarios and the impact of power converter characteristics on the performance of a smart gird. Two possible operational scenarios of the proposed smart grid concept are evaluated and demonstrate that an accurate hardware-in-the-loop (HIL) system can be designed.

ПРОЕКТУВАННЯ СИЛОВИХ ТРАНЗИСТОРНИХ ПЕРЕТВОРЮВАЧІВ ЕНЕРГІЇ ДЛЯ СИСТЕМ АВТОМАТИЗОВАНОГО ЕЛЕКТРОПРИВОДУ ПОСТІЙНОГО СТРУМУ

Purpose. One of the integral parts of modern mechatronic motion modules, where electric motors provide the conversion of electrical energy into useful mechanical action, are power semiconductor converters. At the current stage of industrial development, the use of energy converters as a part of a fully controlled semiconductor switches opens wide opportunities for the development and implementation of highly efficient resource- and energy-saving devices. Methodology. Two types of converters are widely used in automated DC electric drive systems: controlled thyristor rectifiers and pulse-width DC converters, the principle of operation of which is based on the key mode of operation of the regulating semiconductor, which periodically connects the source voltage to the output circuit. The paper presents a laboratory sample of a power semiconductor DC energy converter, which can ensure reliable motor operation in both motor and braking modes. Results. The presented transistor energy converter consists of two main parts: the first part performs the main role – control, and it includes a control unit, a microcontroller, and a device for displaying current information. The second part is a power module, which includes the necessary power supply modules, control drivers and power transistor switches of the converter. To obtain high quality transients of the electric drive system, the circuit is equipped with additional sensors of current, voltage and speed, which takes part in the formation of the control signal and in the protection systems against overvoltage and current jumps. Practical value. The paper substantiates the parameters of the components and proposes developed technical solutions for the construction of a microprocessor control system for a transistor DC energy converter. It is shown that in order to ensure a constant generator mode in automated electric drive systems, where the primary energy converter is an uncontrolled rectifier, it is expedient to install an energy discharge circuit in the DC link. References 18, figures 14.

Reverse Conduction Loss Minimization in GaN‑Based PMSM Drive

Gallium nitride (GaN) devices are becoming more popular in power semiconductor converters. Due to the absence of the freewheeling substrate diode, the reverse conduction region is used in GaN transistors to conduct the freewheeling current. However, the voltage drop across the device in the reverse conduction mode is relatively high, causing additional power losses. These losses can be optimized by adequately adjusting the dead-time issued by the microcontroller. The dead-time loss minimization strategies presented in the literature have the common disadvantage that either additional hardware or specific converter data are needed for their proper operation. Therefore, this paper’s motivation is to present a novel dead-time loss minimization method for GaN-based high-frequency switching converters for electric drives that does not impose additional requirements on the hardware design phase and converter data acquisition. The method is based on optimizing the current controllers’ output with a simple perturb-and-observe tracker. The experimental results show that the proposed approach can minimize the dead-time losses over the whole drive’s operating range at the cost of only a moderate increase in software complexity.

Energy Optimization of the 'Shore to Ship' System-A Universal Power System for Ships at Berth in a Port.

One of the most effective methods of limiting air pollution emissions by ships at a berth in a port is the power connection of ships to the on-shore system. “Shore to Ship” (STS)—A universal system for the connection of the ship’s electrical power network with the on-shore network—ensures the adoption of the voltage and frequency of the on-shore network for the exploitation of various types of ships in the port. The realization of such a system is possible due to the use of semiconductor technologies during the construction of mechatronic systems (i.e., systems that ensure the maintenance of electricity parameters). The STS system ensures energy efficiency for high-power ship systems through the use of an active semiconductor converter. This article presents an analysis of steady state electromagnetic and energy processes, allowing the determination of the active and reactive power and losses in the STS system. The presented analytical research enables the development of a control algorithm that optimizes the system energy efficiency. In the article, the control methods allowing the optimization of the energy characteristics of the system are considered and investigated. On the basis of theoretical studies, a model was developed in the Matlab-Simulink environment, which allowed us to study steady and transient processes in the STS system in order to reduce losses in power lines and semiconductor converters.

Improving the Reliability of Semiconductor Converters

This paper considers the opportunities for improving the reliability of power semiconductor converters by increasing the installed capacity margin and modifying the configuration of power circuit diagrams. As shown by regression analysis, the unit cost of an autonomous voltage inverter with an increase in the installed capacity of the frequency converter rises by about 25%. It is shown that the machine and the semiconductor converter are used most efficiently in six phases, whereas the number of valves in the semiconductor converter is 4m, where m is the number of phases. A further increase in the number of phases does not significantly reduce the phase current, but significantly increases the number of keys in the valve converter. It is shown that an increase in the phase of power circuit layouts allows using the electric machine more fully in terms of capacity and reduce the phase current in semiconductor converters by more than twofold. It is established that the new solutions allow reducing by almost twofold the number of failures in electric drives of more than 500 kW in capacity, while the costs of power electric equipment increase by no more than 25%.

Research of electric drive systems with real time software configurable control

Subject of Research. The paper discusses design principles of educational laboratory bench for practical research of electric drive control systems. The laboratory bench provides training opportunities for students in “Control of Electrical Drives” course and is used to increase the efficiency of material acquisition. Method. The proposed solution was based on the method of mutual loading of electric machines powered by the power converters with a common direct current link. At that, one electric machine can be used as a tested one, and the other as a load one, and vice versa. The flow of power from a machine operating in generator mode to a machine operating in motor mode was ensured, which provides an energy-saving mode of operation when power is consumed only from the network to cover losses in power converters and the machine unit. To study the various structures of control systems for direct and alternating current motors, a method for software creation with a freely configurable structure was proposed. Main Results. The paper describes laboratory stands that contain a two-machine unit, where each electric motor receives power from its power semiconductor converter controlled by a real-time microcontroller control system. The software has been implemented for the synthesis of the control researched structure using the control system settings. The system setting is performed by a number of freely configurable control elements, which are then compiled into a control algorithm for the microcontroller. To ensure the safe execution of the experiment, the control algorithm works in conjunction with the main on-line software. Thus, protection for electric motors and power converters is provided. Thanks to the built-in protection software, it has become possible to achieve reliable operation of electric drives with the power of 1.5 kW, as well as to realize characteristics close to industrial ones. The paper describes in detail the features of laboratory equipment and software for the system of an induction motor field-oriented control. This example demonstrates the setting of control systems, compiling of executable code, an experiment procedure and evaluation of results. Practical Relevance. The considered approaches to the educational equipment creation can be used in the design of similar educational equipment in related disciplines. The results are applicable for scientific and research-pedagogical staff during the course of specialist training in the field of electric drive control systems. The presented equipment has been actively used for more than 5 years and can be of practical value in the educational process.

Mathematical Modeling of the Electric Drive with Universal Power Semiconductor Converter

In the article are examined the mathematical models of the electric drive of direct and alternating current with the universal power semiconductor converter. The functional diagram of electrical power semiconductor converter is described. Are given the oscillograms of the output voltage of power semiconductor converter, obtained with the aid of the model of converter. Are determined the static and dynamic characteristics of the electric drive of direct and alternating current with the universal power semiconductor converter, which make it possible to positively estimate fitness for work and accuracy of the systems of electric drive in the steady-state and dynamic behaviors of work. The experimental studies, carried out in the laboratory mock-up of the electric drive of direct and alternating current with the universal power semiconductor converter, testify about the sufficiently high adequacy of the developed models and confirm the practical possibility of designing of the class of universal semiconductor converters for regulating the angular velocity of the electric motors of direct and alternating current.

40th Anniversary of Technical Committee on Semiconductor Power Converter —Past, Present, and Future—

40th Anniversary of Technical Committee on Semiconductor Power Converter —Past, Present, and Future—

A smart cascaded H-bridge multilevel inverter with an optimized modulation techniques increasing the quality and reducing harmonics

<span>The world community relied heavily on fossils energies but just after the big oil crisis the use of renewable energy has greatly increased and has become the main interest of many countries for its many advantages such as: minimal impact on the environment, renewable generators requiring less maintenance than traditional ones and it has also a great impact on economy. It is easy to get charmed by the advantages of using the renewable resources but we must also be aware of their disadvantages. One of the major disadvantages is that the renewable energy resources are intermittent and thus they have led scientists to develop new semiconductor power converters among which are the multilevel inverter. In this paper a new smart multi-level inverter is proposed so as to increase its levels according to the user’s needs and also to avoid the impact of shades and the intermittence on photovoltaic panels. We also propose a modification on the multicarrier aiming to reduce the harmonics. This modification introduces a sinusoidal wave compared with trapezoidal multi-carrier to generate the pulses. In order to obtain the line voltages and the total harmonic distortions (THD) MATLAB/SIMULINK is used.</span>