Three-phase High Power Research Articles

Design of Electrostatic Precipitator Power System Based on Auto Disturbance Rejection Controller

The paper designs a three-phase high voltage power supply system based on active disturbance rejection controller which make single-chip microcomputer ATmega128 as the main control chip and the system improve the stability and control precision of dust removing power. Engineering practice shows that, the DC power supply system has the advantages of convenient operation, high work efficiency, system stability.

Isolated Three-Phase High Power Factor Rectifier Based on the SEPIC Converter Operating in Discontinuous Conduction Mode

This paper presents the analysis and design of a three-phase high power factor rectifier, based on the dc-dc single-ended primary-inductance converter (SEPIC) operating in discontinuous conduction mode, with output voltage regulation and high frequency isolation. The input high power factor is naturally attained through the operational mode without the use of current sensors and a current control loop. To validate the theoretical analysis, a design example and experimental results for a 4-kW, 380-V line-to-line input voltage, 400-V output voltage, 0.998 power factor, 40-kHz switching frequency, and 4% input current total harmonic distortion laboratory prototype are presented, considering two distinct modulators. In addition, experimental results for the output voltage closed-loop control are presented.

Optimization of a New Three-Phase High Voltage Power Supply for Industrial Microwaves Generators with N Magnetrons by Phase (Treated Case N=1)

Optimization of a New Three-Phase High Voltage Power Supply for Industrial Microwaves Generators with N Magnetrons by Phase (Treated Case N=1)

Research on Three-Phase VIENNA Converter for PFC

In order to get the stable output, the small switch pressure resistance and the high power factor with the high power three-phase rectifier, the three-phase VIENNA PFC circuit topology was studied, and the principle of VIENNA rectifier was investigated, based on the original concept of the control method, the interval control with hysteresis control method were used to control the whole rectifier circuit. Throughout the system design had been completed, the MATLAB model is built for the design of the circuit simulation, the simulation results show that the system output is stabilizing output, and the pressure resistance of the switch device is half of the output voltage, and the input power factor is 1.And set up some small prototype to verify the control method of the rectifier.

An Integrated 20-kW Motor Drive and Isolated Battery Charger for Plug-In Vehicles

For vehicles using grid power to charge the battery, traction circuit components are not normally engaged during the charging time, so there is a possibility to use them in the charger circuit to have an on-board integrated motor drive and battery charger. An isolated high-power three-phase integrated motor drive and charger based on a split-phase permanent magnet motor is presented in this paper. The motor winding connections are reversible by a relay-based switching device for traction and battery charging. In traction mode, the motor is a classical three-phase motor, but in charging mode it is a rotating isolating transformer providing a three-phase voltage source for the inverter to charge the battery. A mathematical model of the motor with six stator windings is presented for an arbitrary phase shift in windings. For the charging mode, the split-phase motor grid synchronization process and charge control are explained including the developed controller. A 20 -kW system is designed and implemented to verify the proper operation of the proposed system. Simulation and practical results are provided to show the system performance in terms of functionality, dynamic response, and efficiency. Moreover, some discussions, recommendations, and limitations are provided to give more practical insights.

Modeling of New Three-Phase High Voltage Power Supply For Industrial Microwave Generators With One Magnetron Per Phase

This original work treats the feasibility study of a new HV power supply with a three-phase character, supplying a magnetron 800 Watts-2450 MHz per phase, for industrial microwave generators from the modeling with the EMTP code of a single-phase HV power supply for one magnetron. The exploitation of the modeling, with EMTP code, of the power system for one magnetron is to use, essentially, the developed model of its transformer, which is a π quadruple, consisting of saturable inductances able to translate the non-linear phenomena of saturation, while guaranteeing the stabilization process of the magnetron current. Using the new power supply device with a three-phase character and the EMTP code, the feasibility study, in nominal mode, of the three-phase power supply was performed satisfactory. The analysis of the results obtained helped to confirm the possibility of functioning of this new system without interaction between magnetrons, which provides, relative to the current device, gains of size, volume, cost of implementation and maintenance and makes this new system more economical, while guaranteeing the regulation process of the current in each magnetron. DOI: http://dx.doi.org/10.11591/ijece.v3i2.2409

Development of High Power Density Three-Phase Inverter

A high power density three-phase unit with the forced-air cooling, which has 10kW power capacity, is developed in this report. The high power three-phase unit is composed of three SiC(Silicon Carbide) power module, cooling fan, DC capacitor, gate-drive circuit, and EMI filter. And also, the design method and the evaluations of the power module, cooling system, gate-drive circuit, and EMI filter are discussed in case that the switching frequency is 50kHz. The volume of the DC/AC converter, EMI filter, and device temperature in the rated output are respectively designed to become 220 degree, 250cc, and 120cc.

Hybrid Active Third-Harmonic Current Injection Mains Interface Concept for DC Distribution Systems

This paper presents the design and implementation of a three-phase high power factor mains interface concept appropriate for many power electronic applications such as supplies for dc power distribution systems in telecommunication, electric vehicle battery charging, future more electric aircraft, variable-speed ac drives, and high power lighting systems. The circuit topology comprises a buck-type power factor correction rectifier circuit built by the combination of an active third-harmonic injection rectifier and a series-connected dc-dc buck-type converter. The characteristics of this rectifier topology, including the principles of operation, modulation strategy, suitable control structure, and dimensioning equations, are described in this paper. The feasibility of the presented converter for buck-type rectifier applications is demonstrated by means of a constructed hardware prototype.

시간차분 유한요소법을 이용한 대용량 삼상 변압기의 정상상태 해석에 관한 연구

This paper presents the fast steady state analysis using time-stepping finite element method for a high power three-phase transformer. The high power transformer spends huge computational cost of the time-stepping finite element method. It is because that the high power transformer requires a lot of time to reach steady state by its large inductance component. In order to reduce computational cost, in this paper, the adaptive time-step control algorithm combined with the embedded 2nd 4th singly diagonally implicit Runge-Kutta method and the analysis strategy using variation of the winding resistance are studied, and their numerical results are compared with those from the typical time-stepping finite element method.

Short-Circuit Fault Protection Strategy for High-Power Three-Phase Three-Wire Inverter

This paper proposes a four-stage fault protection scheme against the short-circuit fault for the high-power three-phase three-wire combined inverter to achieve high reliability. The short-circuit fault on the load side is the focus of this paper, and the short-circuit fault of switching devices is not involved. Based on the synchronous rotating frame, the inverter is controlled as a voltage source in the normal state. When a short-circuit fault (line-to-line fault or balanced three-phase fault) occurs, the hardware-circuit-based hysteresis current control strategy can effectively limit the output currents and protect the switching devices from damage. In the meantime, the software controller detects the fault and switches to the current controlled mode. Under the current controlled state, the inverter behaves as a current source until the short-circuit fault is cleared by the circuit breaker. After clearing the fault, the output voltage recovers quickly from the current controlled state. Therefore, the selective protection is realized and the critical loads can be continuously supplied by the inverter. The operational principle, design consideration, and implementation are discussed in this paper. The simulation and experimental results are provided to verify the validity of theoretical analysis.

A Novel Active Interphase Transformer Scheme to Achieve Three-Phase Line Current Balance for 24-Pulse Converter

A new active interphase transformer (IPT) scheme to achieve three-phase line current balance for a 24-pulse converter is proposed in this paper. The proposed active IPT scheme consists of three IPT and a current-controlled inverter with required rating only 1.16% of system power rating. A current injection method for an active IPT is also proposed in this paper. The balance of three-phase current and high power quality can be achieved by injecting compensation current into the secondary winding of the active IPT. Moreover, the proposed scheme can operate in flexible load configurations, by which separated loads can be connected to the separated outputs of the converter independently. The operation criteria for flexible load arrangements are analyzed to obtain better performance. System simulation is conducted and a 6-kW laboratory prototype is built both for evaluation and test. Both simulation and experimental results demonstrate the validity of the proposed scheme.

A Three-Phase High Frequency Semi-Controlled Battery Charging Power Converter for Plug-In Hybrid Electric Vehicles

This paper presents a novel analysis, design, and implementation of a battery charging three-phase high frequency semi-controlled power converter feasible for plug-in hybrid electric vehicles. The main advantages of the proposed topology include high efficiency; due to lower power losses and reduced number of switching elements, high output power density realization, and reduced passive component ratings proportionally to the frequency. Additional advantages also include grid economic utilization by insuring unity power factor operation under different possible conditions and robustness since short-circuit through a leg is not possible. A high but acceptable total harmonic distortion of the generator currents is introduced in the proposed topology which can be viewed as a minor disadvantage when compared to traditional boost rectifiers. A hysteresis control algorithm is proposed to achieve lower current harmonic distortion for the rectifier operation. The rectifier topology concept, the principle of operation, and control scheme are presented. Additionally, a dc-dc converter is also employed in the rectifier-battery connection. Test results on 50-kHz power converter system are presented and discussed to confirm the effectiveness of the proposed topology for PHEV applications.

DSTATCOM topologies for three-phase high power applications

This paper proposes distribution static compensator topologies for application in three-phase high power distribution systems. These topologies overcome both the voltage and current rating constraints imposed by the semiconductor switches by the use of three single-phase multi-secondary transformers. Five topologies, namely, four leg-group, three leg-group split-capacitor, H bridge-group, three leg-group and two leg-group are suggested. These can effectively compensate unbalance, harmonics and low power factor of the load currents. Apart from the use of minimum number of current sensors and a single capacitor, the control circuit is very simple. It provides the electrical isolation and security deemed essential for high voltage systems. A detailed comparison is made for these topologies. Based on the hardware requirement and compensation quality, the four leg-group and three leg-group topologies are shown to be superior than the other structures for application in three phase four-wire and three-wire systems respectively. They are validated through extensive simulation studies using PSCAD in a three-phase four-wire power network with non-linear unbalanced load. Experimental verification is conducted for H bridge-group topology on a single phase system using a DSP-based prototype laboratory model.

An optical system with potential for remote health monitoring of subsea machinery

A prototype fibre-optic sensing system is described with potential to remotely monitor the condition of three-phase variable frequency subsea motors and electric submersible pumps. An indication that the integrity of a powerful electric motor may be compromised can be gained by spectral analysis of the stator drive current, the phases of the currents, the measurement of vibration at specific locations on the motor and the temperature of the bearings. The optical interrogation system is based on an imbalanced Mach–Zehnder fibre interferometer, illuminated with a broadband source with fibre Bragg gratings (FBGs) used as the basic transducers for the current and vibration measurements. Signals were recovered at a distance of 7 km, for the ‘in house’ current sensor at an effective ac current of 500 A at frequencies from 10 to 1000 Hz with a S/N ratio of 45 dB, together with the relative phases between the currents. These signals were generated with a simulated high power three-phase electric motor. A commercial accelerometer was incorporated into the system which demonstrated a sensitivity of 1 mg Hz−1/2 also from 10 to 1000 Hz. As the interrogation system can only be used to detect dynamic signals, a second interrogation for quasi-static temperature measurements is required; although this was not deployed, possible applications other than bearing temperature measurement are considered.

A Three-Phase Current-Fed DC/DC Converter With Active Clamp for Low-DC Renewable Energy Sources

This paper focuses on a new three-phase high power current-fed DC/DC converter with an active clamp. A three-phase DC/DC converter with high efficiency and voltage boosting capability is designed for use in the interface between a low-voltage fuel-cell source and a high-voltage DC bus for inverters. Zero-voltage switching in all active switches is achieved through using a common active clamp branch, and zero current switching in the rectifier diodes is achieved through discontinuous current conduction in the secondary side. Further, the converter is capable of increased power transfer due to its three-phase power configuration, and it reduces the RMS current per phase, thus reducing conduction losses. Moreover, a delta-delta connection on the three-phase transformer provides parallel current paths and reduces conduction losses in the transformer windings. An efficiency of above 93% is achieved through both improvements in the switching and through reducing conduction losses. A high voltage ratio is achieved by combining inherent voltage boost characteristics of the current-fed converter and the transformer turns ratio. The proposed converter and three-phase PWM strategy is analyzed, simulated, and implemented in hardware. Experimental results are obtained on a 500-W prototype unit, with all of the design verified and analyzed.

Implementation of Space Vector Based Hysteresis Current Control for a Three-Phase High Power Factor Converter

In this paper, an implementation of a space vector modulation (SVM) based hysteresis current controller (HCC) for the control of a three-phase high power factor rectifier is proposed. The SVM-based HCC scheme is designed, simulated and implemented. The technique combines the best features of the SVM and HCC techniques. The controller determines a set of state space vectors from a region detector and then applies a space vector selected according to HCC. A set of space vectors in a region, including the zero space vector for a reduced number of switchings, is determined from the output signals of three comparators with a hysteresis band a little larger than that of the main HCC. A simple experimental implementation is proposed and the simulation and experimental results of the SVM-based HCC are discussed in the paper.

Zero-Sequence Current Control of Modular Active Power Filter for High Power Three-Phase Three-Wire Electrical Networks

Since the development of the first control strategy for the active power filters (APF) introduced by H. Akagi [H. Akagi, Y. Kanazawa,A. Nabae, Generalized theory of the instantaneous reactive power in three-phase circuits, in: Proceedings of International Power Electronics Conference, Tokyo, Japan (1983) 1375–1386.], many efforts have been concentrated to improve their performances. However, when electrical networks supplies high current non-linear loads, a single inverter-based APF has limited power capability. In this paper, we studied parallel operation achieving high power level. More particularly, we examined a modular APF based on two three-phase inverters. This structure allows zero-sequence current circulating through the inverters, as demonstrated by using averaged modelling of the APF. To solve this problem and based on previous averaged model, we proposed a new optimal control strategy, suppressing the zero-sequence circulating current. Simulation results validate the proposed control.

Three-phase high power factor AC∕DC converter

A unidirectional three-phase AC/DC converter is proposed to obtain almost unity power factor, draw sinusoidal line currents and keep the DC-bus voltage constant. Two active switches and two power diodes are used in each converter leg to generate a three-level PWM waveform on the AC terminal voltages. The proposed converter has simpler circuit configuration compared with the conventional three-level PWM converters. The classical proportional-integral voltage controller and the hysteresis current controller are adopted in the control scheme to achieve DC-bus voltage regulation and line-current command tracking. A neutral-point voltage compensator is used to balance the neutral-point voltage due to load change. The validity and effectiveness of the proposed control algorithm is verified through simulations and experimental results.

Three-phase high power factor rectifier with two NPC legs

A current-controlled switching mode rectifier with a reduced switch count is presented. The proposed rectifier is based on the neutral-point-clamped topology. Only eight power switches with voltage stress of half DC-link voltage and four clamped diodes are employed in the proposed rectifier instead of 12 power switches and six clamped diodes used in the conventional neutral-point-clamped rectifier. The purposes of the proposed control strategy are to keep the factor correction at unity, to reduce current harmonics and to regulate DC bus voltage. The analysis and mathematical model of the rectifier is derived and the control strategy is provided. The effectiveness of the proposed control scheme is verified by the experimental results.

Two three-phase high power factor rectifiers that apply the third harmonic current injection and passive resistance emulation

Two high power factor rectifiers that apply the third harmonic current injection principle and passive resistance emulation are presented in this paper. Two methods of current injection, simultaneous current injection in all three of the phases, and current injection to only one of the phases, are discussed. Conditions for the optimal third harmonic current injection are derived, structures of the rectifiers that apply passive resistance emulation, enabling recovery of the power taken by the current injection network, are presented. The proposed resistance emulator consists of a transformer, two diodes and a capacitor. Choice of the passive components is discussed, and their values are proposed, volt-ampere ratings of the magnetic components are derived. Influence of the higher order harmonics is discussed. Dependence of the input current total harmonic distortion on the load level is presented for both of the current injection methods. Analytically obtained results are verified on 1.5 kW experimental rectifiers.