Switch-mode Rectifier Research Articles

Development of a Wind Interior Permanent-Magnet Synchronous Generator-Based Microgrid and Its Operation Control

This paper presents the development of a wind interior permanent-magnet synchronous generator (IPMSG)-based dc microgrid and its operation control. First, the derated characteristics of PMSG systems with various ac/dc converters and operation controls are comparatively analyzed. Then, the IPMSG followed by a three-phase Vienna switch-mode rectifier is developed to establish the common dc bus of dc microgrid. Good developed power and voltage regulation characteristics are achieved via the proposed commutation tuning, robust current, and voltage controls. Second, a single-phase three-wire inverter is constructed to serve as the test load. Good ac 220 V/110 V output voltage waveforms under unknown and nonlinear loads are preserved by the developed robust waveform tracking control scheme. Third, a battery energy storage system is established, and the fast energy storage support response is obtained via the proposed droop control approach with adaptive predictive current control method. In addition, a chopped dump load is equipped to enhance the energy balance control flexibility.

An EV SRM Drive Powered by Battery/Supercapacitor With G2V and V2H/V2G Capabilities

This paper develops an electric vehicle switched-reluctance motor (SRM) drive powered by a battery/supercapacitor having grid-to-vehicle (G2V) and vehicle-to-home (V2H)/vehicle-to-grid (V2G) functions. The power circuit of the motor drive is formed by a bidirectional two-quadrant front-end dc/dc converter and an SRM asymmetric bridge converter. Through proper control and setting of key parameters, good acceleration/deceleration, reversible driving, and braking characteristics are obtained. In idle condition, the proposed motor drive schematic can be rearranged to construct the integrated power converter to perform the following functions: 1) G2V charging mode: a single-phase two-stage switch-mode rectifier based charger is formed with power factor correction capability; 2) autonomous V2H discharging mode: the 60-Hz 220-V/110-V ac sources are generated by the developed single-phase three-wire inverter to power home appliances. Through the developed differential mode and common mode control schemes, well-regulated output voltages are achieved; 3) grid-connected V2G discharging mode: the programmed real power can be sent back to the utility grid.

전기차 배터리 충전기용 강인한 단위 입력 역률 제어장치

This study develops a digital control scheme with power factor correction for a front-end converter in an electric vehicle battery charger. The front-end converter acts as the boost-type switching-mode rectifier. The converter assumes the two roles of the battery charger, which include power factor control and robust charging performance. The proposed control scheme consists of a charging control algorithm and a grid current control algorithm. The scheme aims to obtain unity input power factor and robust performance. Based on the linear average model of the converter, a constant-current constant-voltage charging control algorithm that passes through only one proportional-integral controller and a current feed-forward path is proposed. In the current control algorithm, we utilized a second band pass filter, a single-phase phase-locked loop technique, and a duty-ratio feed-forward term to control the grid current to be in phase with the grid voltage and achieve pure sinusoidal waveform. Simulations and experiments were conducted to verify the effectiveness of the proposed control scheme, both simulations and experiments.

SMR 회로를 이용한 소형풍력발전 시스템의 센서리스 퍼지 MPPT제어

This paper proposes a low-cost switched-mode rectifier (SMR) for a small-scale wind turbine with a permanent magnet synchronous generator (PMSG) system. Also, a sensorless Fuzzy MPPT control is realized by the proposed system. In the PMSG system with the SMR, the synchronous impedance can be replaced as the input inductor of a boost converter. Moreover, the sensorless MPPT control using the Fuzzy technique is carried out by the duty-ratio regulation of the SMR. The relation between the generating power and the duty-ratio is ruled by the chain rule. The wind turbine model is implemented by the squirrel cage induction motor and generated the variable torque when the generator speed is varied. To verify the performance of the proposed system, simulation and experimental results are executed.

Multiloop Interleaved Control for Three-Level Switch-Mode Rectifier in AC/DC Applications

In this paper, multiloop interleaved control (MIC) is proposed, and it is combined with conventional multiloop control and the interleaved pulsewidth modulation scheme. The average behavior of the interleaved three-level switch-mode rectifier (SMR) behaves similar to the conventional boost-type SMR even though two capacitor voltages are imbalanced. It implies that conventional multiloop control can be applied to the interleaved three-level SMRs to achieve the desired power factor correction function. The proposed MIC is digitally implemented and verified in a field-programmable-gate-array-based system. The provided results show that MIC stably works and the capacitor voltages are eventually balanced during the system operations.

Interleaved Current Sensorless Control for Multiphase Boost-Type Switch-Mode Rectifier With Phase-Shedding Operation

Multiphase boost-type switch-mode rectifiers (SMRs) are often used to improve the efficiency of ac-dc conversion. In particular, the light-load efficiency can be increased by turning off some phases (i.e., phase-shedding operation). To keep the number of feedback signals fixed regardless of the topology phase number N, the interleaved current sensorless control (ICSC) with consideration of the phase-shedding operation is proposed in this paper. In ICSC, no current sensing is needed, and only input and output voltages are sensed. To demonstrate the proposed ICSC, a two-phase boost-type SMR is established for test, and the proposed ICSC is implemented in a field-programmable-gate-array-based system. The provided simulation and experimental results show good performance of the proposed ICSC.

Development of Digital Control for High Power Permanent-Magnet Synchronous Motor Drives

This paper is concerned with the development of digital control system for high power permanent-magnet synchronous motor (PMSM) to yield good speed regulation, low current harmonic, and stable output speed. The design of controller is conducted by digitizing the mathematical model of PMSM using impulse invariance technique. The predicted current estimator, which is insensitive to motor feedback currents, is proposed to function under stationary frame for harmonic current suppression. In the AC/DC power converter, mathematical model anddc-link voltage limit of the three-phase switch-mode rectifier are derived. In addition, a current controller under synchronous frame is introduced to reduce the current harmonics and increase the power factor on the input side. A digital control system for 75 kW PMSM is realized with digital signal processor (R5F5630EDDFP). Experimental results indicate that the total harmonic distortion of current is reduced from 4.1% to 2.8% for 50 kW output power by the proposed predicted current estimator technique.

On a Bidirectional Adapter With G2B Charging and B2X Emergency Discharging Functions

This paper presents a bidirectional adapter having the functions of charging and discharging, providing 110 V/60 Hz emergency output from the battery embedded in a laptop computer, in electric vehicles, in an uninterruptible power supply, or in other possible appliances. The developed adapter possesses the grid-to-battery and battery to any emergency need (B2X) capabilities. In discharging mode, a front-end dc/dc converter is equipped to establish boosted dc-link voltage from battery for the followed inverter. Then, an H-bridge single-phase inverter is established to yield 110 V/60 Hz emergency source for critical appliances. The two power stages are implemented using an intelligent power module (IPM) with three legs. Good output ac sinusoidal voltage waveforms under unknown and nonlinear loads are obtained by the proposed model following the control scheme, with its tracking error regulation via proportional-plus-integral control and resonant control. Further improvement in waveform quality is achieved by robust control. Conversely, in charging mode, a buck switch-mode rectifier based charger is formed using the same IPM. The performance and rating analyses as well as the design for its power circuit components are derived in detail simultaneously. Satisfactory charging control performance and line drawn power quality are obtained.

SMR을 갖는 소형풍력발전시스템의 센서리스 MPPT제어

A small-scale wind power generation system with a switched-mode rectifier(SMR) is proposed. To simplify the converter circuit of the wind power generation system, the synchronous inductors of the permanent magnet synchronous generator(PMSG) replace the inductor for the boost converter. The sensorless maximum power point tracking(MPPT) control is carried out for the wind power generation system with the SMR. The proposed system is verified through the simulations and the experiments.

Variable Structure Controller for Generator Side Converter of Variable Speed PMSG Wind Energy Conversion System

paper presents a novel control strategy based on variable structure theory (VST) for the generator side converter to regulate the dc link voltage of a direct driven PMSG wind energy conversion system (WECS). The validity of the technique is theoretically analyzed, and the design procedure is presented. The primary merit of the proposed technique is that it does not require an anemometer or prior knowledge of a system, but has an accurate and fast dynamic response to wind speed fluctuations. Modeling of Wind turbine, PMSG, controlling of generator side switch mode converter and Simulation results are presented. Simulation is done in MATLAB/POWERSYSTEM environment. Index terms Variable-speed wind turbine, PMSG, VSCS, SMC and switch-mode rectifier (SMR).

Control of a Stand-Alone Variable Speed Wind Energy Supply System

This paper presents a simple control strategy for the operation of a variable speed stand-alone wind turbine with a permanent magnet synchronous generator (PMSG). The PMSG is connected to a three phase resistive load through a switch mode rectifier and a voltage source inverter. Control of the generator side converter is used to achieve maximum power extraction from the available wind power. Control of the DC-DC bidirectional buck-boost converter, which is connected between batteries bank and DC-link voltage, is used to maintain the DC-link voltage at a constant value. It is also used to make the batteries bank stores the surplus of wind energy and supplies this energy to the load during a wind power shortage. The load side voltage source inverter uses a relatively complex vector control scheme to control the output load voltage in terms of amplitude and frequency. The control strategy works under wind speed variation as well as with variable load. Extensive simulation results have been performed using MATLAB/SIMULINK.

Comparative study of a small size wind generation system efficiency for battery charging

This paper presents an energetic comparison between two control strategies of a small size wind generation system for battery charging. The output voltage of the direct drive PMSG is connected to the battery through a switch mode rectifier. A DC-DC boost converter is used to regulate the battery bank current in order to achieve maximum power from the wind. A maximum powertracking algorithm calculates the current command that corresponds to maximum power output of the turbine. The DC-DC converter uses this current to calculate the duty cycle witch is necessary to control the pulse width modulated (PWM) active switching device (IGPT). The system overview and modeling are presented including characteristics of wind turbine, generator, batteries, power converter, control system, and supervisory system. A simulation of the system is performed using MATLAB/SIMULINK.

A New Single-Stage Multilevel Type Full-Bridge Converter Applied to closed loop condition

Switch Mode rectifiers for power-factor correction have gained considerable attention, due to the increasing demand for improved power quality. A new three-phase single-stage rectifier with Brushless DC motor is proposed in this paper. Each converter operates in the continuous conduction mode (CCM), which allows a high power factor and a small EMI filter. The outstanding features of the proposed rectifier are that it can produce input currents that do not have dead band regions and an output current that can be continuous when the converter is operating from maximum load to at least half of the load. Here we proposed full bridge converter with machine load condition system is validated through MATLAB/SIMULINK Platform.

Design and control of a switched-reluctance motor-driven cooling fan

This study presents the design, implementation and driving control of a switched-reluctance motor (SRM)-driven cooling fan. First, after exploring the motor structural features, a 70-W three-phase SRM with six of four teeth is designed, manufactured and estimated its key parameters. Secondly, a Miller converter and an asymmetric bridge converter are constructed with their switching and commutation shift schemes being properly designed. Thorough experimental evaluations are conducted for the SRM-driven fan powered by different converters. It shows that proper commutation shift can enhance the driving performance of SRM drive, particularly for the one powered using Miller converter. Further comparative performance assessment is also made between the developed SRM-driven fan and an available brushless DC motor fan with the same fan blade, the results confirm the application potential possessed by SRM. Finally, a front-end flyback switch-mode rectifier (SMR) is developed and used to establish well-regulated DC-link voltage for the SRM converter from mains with satisfactory line-drawn power quality.

Maximum-Torque-per-Ampere Control of Phase Advance Modulation of an SPM Wind Generator

Surface permanent-magnet (SPM) machines are normally operated by controlling the d- and q-axis currents. This paper examines the control of SPM generators based on controlling the terminal voltage magnitude V and power-factor angle 8. This is well suited for generator operation when using a switched-mode rectifier and avoids the need for a rotor position sensor. The parameters required for generating a given value of torque with minimum phase current in order to minimize copper losses are derived in this paper. This will be achieved by controlling V and 8 to keep the d-axis current equal to zero at low speed, before switching to field-weakening control at higher speeds. Simulated and experimental results will be used to verify the control strategy and the efficiency achieved.

A Two-Hop Wireless Power Transfer System With an Efficiency-Enhanced Power Receiver for Motion-Free Capsule Endoscopy Inspection

This paper presents a wireless power transfer system for a motion-free capsule endoscopy inspection. Conventionally, a wireless power transmitter in a specifically designed jacket has to be connected to a strong power source with a long cable. To avoid the power cable and allow patients to walk freely in a room, this paper proposes a two-hop wireless power transfer system. First, power is transferred from a floor to a power relay in the patient's jacket via strong coupling. Next, power is delivered from the power relay to the capsule via loose coupling. Besides making patients much more conformable, the proposed techniques eliminate the sources of reliability issues arisen from the moving cable and connectors. In the capsule, it is critical to enhance the power conversion efficiency. This paper develops a switch-mode rectifier (rectifying efficiency of 93.6%) and a power combination circuit (enhances combining efficiency by 18%). Thanks to the two-hop transfer mechanism and the novel circuit techniques, this system is able to transfer an average power of 24 mW and a peak power of 90 mW from the floor to a 13 mm × 27 mm capsule over a distance of 1 m with the maximum dc-to-dc power efficiency of 3.04%.

Simple Sensorless Maximum Power Extraction Control for a Variable Speed Wind Energy Conversion System

This paper proposes a simple sensorless maximum power extraction control strategy for a variable speed wind energy conversion system (VSWECS) based on permanent magnet synchronous generator (PMSG). The PMSG is connected to the grid through a switch mode rectifier and a three phase voltage source inverter (VSI). Control of the generator side converter is used to achieve maximum power from the available wind power. This by Simple estimating of PMSG generator speed and using the estimated generator speed to calculate mechanical power generated from wind power. So, the optimum power coefficient of the wind turbine can be achieved from the governed relation between the generator speed and mechanical power. The grid side voltage source inverter uses a hysteresis current controller to supply power at unity power factor into the grid. Extensive simulations have been performed using MATALB/SIMULINK. Simulation results demonstrate that the controller can extract maximum power from available wind power and achieve unity power factor at the grid with different wind speeds.

Constrained model predictive control strategy for single-phase switch-mode rectifiers

This study presents a new approach to the control problem of single-phase switch-mode rectifiers. The proposed approach is based on a particular model predictive control scheme, incorporated with soft constraints for the errors of the key control targets. This control system is free of portional integral (PI) controllers, which are responsible for poor dynamic performance. Control objectives of sinusoidal input current, approximately unity input power factor, and output voltage regulation are successfully met under both steady state and load or setpoint changes. Considering the significant advantages of multilevel operation, the reflected AC side voltage exhibits an appropriate three-level modulation. The developed control strategy involves improved performance compared with a model-based sliding mode one. The theoretical analysis is validated by measurements on a laboratory prototype, illustrating the feasibility and suitability of the proposed controller for this type of rectifiers.

Establishment of a Switched-Reluctance Generator-Based Common DC Microgrid System

This paper presents a dc microgrid including a switched-reluctance generator (SRG) with isolated boost dc-dc converter, a battery energy storage system, and a single-phase three-wire (1P3W) load inverter for generating ac 220/110 V 60-Hz outputs. The 400-V dc grid is established by the SRG with dc 48-V output followed by a current-fed push-pull (CFPP) dc-dc converter. The robust commutation and dynamic control schemes are developed for the SRG to have excellent output performances. For providing the domestic load power sources, a 1P3W transformerless 220/110 V inverter is established. A master and slave robust control schemes are proposed to yield balanced sinusoidal output voltage waveforms in both voltage outputs under varying load conditions. To improve the dc grid power supporting reliability, a battery energy storage system with bidirectional buck-boost interfacing converter is established. It can support the common dc bus voltage immediately when the main power source fault occurs. Conversely, the battery bank can be charged from the common dc bus through the same converter. Particularly, an auxiliary charger formed by a flyback switch-mode rectifier is equipped to allow the battery to be charged from the plug-in utility power as the long duration of microgrid fault occurs. Normal operation and good operating performance of the established microgrid are verified experimentally.

A Flyback Rectifier With Spread Harmonic Spectrum

This paper presents a flyback switch-mode rectifier (SMR) with spread harmonic spectrum. The SMR switching control is conducted by a charge-regulated pulsewidth modulation (PWM) scheme with constant turn-on period. The inherently stable discontinuous conduction mode operation is preserved to yield good line drawn power quality. In voltage loop, a quantitatively designed PI feedback controller is augmented with a robust error cancellation control scheme. Further improved dc output voltage regulation and input power quality performances are achieved under varied operating conditions. In spread harmonic spectrum control, the harmonic spectral properties of the developed flyback SMR are first analyzed. Then, the dedicated random switching scheme is developed to let its switch current harmonic spectrum be dispersedly distributed. In the proposed random switching scheme, the PWM turn-off period is modulated using 1-b binary sequence, pseudo random binary sequence, and 4-b binary sequences. Under randomized harmonic spectrum, the SMR control performances are not sacrificed.