Converter For Switched Reluctance Motor Research Articles

An Overview of Fault-diagnosis and Fault Tolerance of Power Converters for Switched Reluctance Motor Drive Systems

An Overview of Fault-diagnosis and Fault Tolerance of Power Converters for Switched Reluctance Motor Drive Systems

A Universal-Input On-Board Charger Integrated Power Converter for Switched Reluctance Motor Drive Based EV Application

A Universal-Input On-Board Charger Integrated Power Converter for Switched Reluctance Motor Drive Based EV Application

Quasi-Z-Source-Fed SRM Drive for Torque Ripple Minimization and Speed Range Extension With Three-Switch Conduction

This paper proposes a quasi-Z-source (QZS)-based modular switched reluctance motor (SRM) drive to suppress the source current ripple, minimize the torque ripple, widen the constant torque range and speed range, and enhance the system reliability. To take full advantages of QZS unit and modular power modules, the QZS-based modular SRM converter is firstly constructed. Subsequently, a three-switch conduction-based current compensation mechanism is developed to deal with the torque plummet issue caused by the inherent series excitation mode. Meanwhile, a novel four-region DITC strategy is proposed to further suppress torque ripple. Furthermore, a voltage regulation method is developed based on compensation mechanism to suppress the source current ripple and provide great assistance to implement the above strategy more effectively. In addition, the shoot-through state can be evenly distributed among the four bridge arms, which is conducive to balance the heating dissipation of power devices for improved service life of power converter. To validate the feasibility and effectiveness, the experiments are carried out on a 150W three-phase 12/8 SRM prototype.

Analysis and Design Considerations of a Buck-Boost Energy Recovery-Based Power Converter for SRM Drive

This article presents the development of a dynamic model and a design approach for the recently proposed buck-boost energy recovery circuit (BBERC) based power converter for a switched reluctance motor (SRM). The advantage of an increased demagnetization voltage in reducing the commutation torque ripple is analyzed using analytical and simulation-based studies. Though there have been several studies on the steady state behavior of the energy recovery stage in the literature, the dynamics of the same have never been investigated. An equation-based small signal model to describe the dynamic behavior of the energy recovery stage is proposed, which can be used to estimate the overshoots and oscillations in the inductor current and capacitor voltage during the dynamics. This article also evaluates the effects of discontinuous conduction mode (DCM) of operation of the BBERC on the drive performance, which has also not been addressed in the prior art. Furthermore, a method for the design of the energy recovery stage considering the continuous conduction of the energy recovery inductor is proposed. Additionally, the advantages of BBERC are reemphasized by comparing it with other energy recovery-based topologies such as energy efficient C-dump converter (EECDC). The analyses presented in this article are validated with experiments and simulations.

Fully Integrated Multilevel Power Converter for SRM Drive With Charging Capabilities (G2V) for Electric Vehicle Application

This article presents a fully integrated multilevel power converter topology (IML-PCT) with integrated battery charging capability for a switched reluctance motor (SRM) drive. The battery charger is integrated within the IML-PCT, which eliminates the requirement of any additional module for charging purposes. The proposed IML-PCT applies higher energization and de-energization voltages during the driving mode, which leads to an enhanced constant torque region for SRM drive. For the battery charging mode, the proposed IML-PCT exhibits the characteristics of an onboard charger (OBC) capable of charging the battery energy storage system directly via a standard ac outlet. The OBC functionality is realized by reconfiguring the proposed IML-PCT into an interleaved bridgeless boost power factor correction circuit (IBB-PFCC). The charging inductors for IBB-PFCC are realized by reutilizing/reconfiguring all the windings of the four-phase SRM. Also, with the proposed IBB-PFCC configuration, the charging current in the windings leads to an average zero torque production. Thus, the rotor is kept stationary during battery charging mode without any external braking mechanism. Detailed simulation and experimental studies on a 1.1-kW laboratory prototype four-phase SRM demonstrate ac level-1 (120 V/240 V) charging performance of the proposed IML-PCT.

Implementation Challenges: Universal R-Dump Converter for Switched Reluctance Motor

This study presents the challenges faced while implementing a new converter topology for switched reluctance motor (SRM) drives. A novel converter configuration that can excite the motor directly from the grid supply, i.e., alternating current supply, was proposed in earlier research. The proposed converter topology is designed to draw power directly from an AC grid. This converter is a modified version of the R-dump converter. There are many converter topologies available for excitation of SRM. The uniqueness of the converter topology developed in this research shows that it can use 4 switches per phase, which in turn increases the redundancy of the whole system. Moreover, this topology is well suitable for SRM excitation since the machine coil structure is constructed with 4 coils and 5 terminals. Since this novel converter is having the advantages of operating in AC input voltage, it improves the usefulness of SRM in household applications such as washing machines, hair dryers, and vacuum cleaners. An analysis of real-time implementation challenges faced while realizing the universal R-dump (URD) converter is presented with discussion to overcome the challenges. An experimental setup is made to verify the converter working.

Power electronic converter topologies for switched reluctance motor towards torque ripple analysis

The power converter circuit plays a vital role in electric drives. The converters performance has a significant impact on the drive performance as well as cost. There are different motors applied in electric drives, this study primarily focused on torque ripple analysis of Switched Reluctance Motor (SRM) drive and its converter topologies. The SRM salient poles have the stator outer side and the rotor inner side, which is different from the other polyphase machines. Although there have been a number of converters for SRM drives through the years, each converter has its own set of benefits and drawbacks. The choice of a converter is dictated by the application, this article includes a comparative analysis of SRM converter topologies, two level converters branches and multi-level converters branches were discussed in detail with schematic diagram. Based on the survey it is found that an asymmetrical bridge converter best suits for Electric vehicle application due to its advantage of reducing fault tolerant, fast demagnetization and regenerative braking capability. This paper presents the study of 10 kW SRM Drive controlled by asymmetrical bridge converter, in three different phase modification mode such as 6/4, 8/6 and 10/8 using MATLAB simulation and the torque ripples are analysed for each case.

A Drive Topology for High-Speed SRM With Bidirectional Energy Flow and Fast Demagnetization Voltage

A drive topology composed of a T-type single-phase three-level voltage source rectifier (VSR) and a four-level switched reluctance motor (SRM) converter is proposed in this article. The commonly used diode bridge rectifier presenting degraded power quality is replaced by the VSR to drive the SRM converter. Compared with the conventional split-dc converter, the four-level SRM converter of the proposed drive topology adopts one more switch and one more diode for each phase, but two more operation modes are formed. With the double-voltage demagnetization mode of the four-level SRM converter, the tailing time of demagnetization current is significantly reduced, which increases the utilization of inductance increasing region. All the operation modes of this converter can be implemented successfully, even in the multiphase excitation region. Moreover, a centralized control strategy is proposed to regulate the VSR and SRM together, within which the speed and grid-side power factor are regulated by the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i> -axis component of grid-side current in VSR, respectively. Most importantly, the bidirectional energy flow is realized. An idea-proofed testbench is constructed. The results obtained from the comparative experiments confirm the validity of the proposed drive topology and its control strategy.

Solar‐powered switched reluctance motor‐driven water pumping system with battery support

This work deals with the development of an efficient and reliable solar photovoltaic-fed water pump with a battery energy storage (BES). This system ensures a continuous and rated supply of water in all working conditions. A new control logic for BES is developed, which significantly improves the overall response of the system. The support of the battery as a backup source is obtained through a bidirectional DC-DC converter. Both the charging/discharging control and maximum power tracking of the solar panel are achieved through this bidirectional converter, whereas the voltage asymmetry compensation across split capacitors at DC link and motor drive controls are supervised by switched reluctance motor converter. The performance of the present scheme is examined through both simulated and experimental responses and is found adequate under all operational scenarios.

Improved Power Converter of SRM Drive for Electric Vehicle With Self-Balanced Capacitor Voltages

The regulation of phase currents is bound by the voltage of power source for switched reluctance motor (SRM) drive with conventional asymmetric half-bridge (AHB) power converter in electric vehicle (EV). To avoid the drawback, an improved active boost power converter with self-balanced capacitor voltages is proposed. First, the problems existing in the AHB power converter are analyzed in different stages of each phase current. Then different working modes of the proposed converter are investigated. The corresponding control strategies are implemented in the light of two conduction sequences. The reference phase voltage is obtained with a new method. Then the control signals of the front-end topology are generated by comparing the reference phase voltage with the required value. One significant advantage of the proposed converter is that it can provide different voltages according to the operation condition of SRM dynamically. The other is that the maximum phase voltage the converter can boost is up to three times the supplied voltage. Comparative experiments on a three-phase 12/8 SRM drive validate the performance of the converter and the effectiveness of the control strategies.

A novel modular power converter for SRM drive

In this paper, a novel modular power converter for four-phase switched reluctance motor (SRM) is proposed. Firstly, a converter with motor phases grouped in pairs which share one common converter phase is introduced. This discrete-type converter is equivalent to the asymmetrical half-bridge converter (AHBC) in terms of the number of semiconductor components and functionality. The common converter phase concept enables modularization using two standard, commercially available six-pack IGBT modules, thus simplifying mass production. Compared to existing modular topologies, the proposed modular converter has the advantage of enabling an overlap of current pulses, which is a key feature for the SRM performance at elevated speeds while retaining a minimal number of standard power switch modules. In addition, owing to inherent operating regimes, the proposed modular converter enhances the motor performance over almost the entire range of the exploitation characteristics compared to AHBC and existing modular topologies. The advantages of the proposed modular topology were determined by means of finite element method (FEM) simulations. Experiments confirm the conclusions obtained from FEM analysis and verify the feasibility of the proposed modular converter.

An Integrated Electrified Powertrain Topology With SRG and SRM for Plug-In Hybrid Electrical Vehicle

With the advantages of less carbon dioxide emissions and high fuel efficiency, plug-in hybrid electrical vehicle (PHEV) is an attractive means of transportation. This article presents an electrified powertrain for PHEV containing switched reluctance generator (SRG), switched reluctance motor (SRM), and integrated power converters, which could achieve various driving and flexible on-board charging functions. The operation states of SRG and SRM with the integrated topology is analyzed. Five driving modes for PHEV are implemented and can be smoothly switched by controlling the front-end converter according to the load conditions. For the PHEV charging mode, a single-phase ac–dc rectifier is constituted by the windings and power converter of SRG with the capability of input power factor correction. The traction and auxiliary batteries chargers are formed by the windings and power converter of SRM. Three charging modes also are achieved and no complex control strategies are required to avoid the rotation of rotors. The three-phase 12/8 poles SRG and SRM experimental platform are built. The experiments are carried out to verify the effectiveness of proposed integrated powertrain and the corresponding control schemes.

Modified Dual Output Cuk Converter-Fed Switched Reluctance Motor Drive With Power Factor Correction

The control of a switched reluctance motor (SRM) drive is proposed with a front end power factor correction (PFC) converter. It uses a modified Cuk converter-fed SRM drive to improve power quality at ac mains. The converter configuration consists of two Cuk converters and each of them operates separately for two half-cycles of the supply voltage. The proposed converter generates two identical voltages across two output capacitors to feed a split capacitor converter of a four-phase SRM drive. The proposed pulsewidth modulated ac–dc converter operates in the discontinuous conduction mode to reduce its size and cost by eliminating couple of sensor requirements. The incorporated voltage control loop regulates the dc-link voltage with PFC at ac mains. The SRM is considered for the proposed drive because of its low cost and constructional ease. The motor speed is controlled over a wide range by regulating the PFC converter output dc voltage. The proposed SRM drive is tested for steady-state and dynamic state conditions on a developed prototype in the laboratory. The obtained test results demonstrate good drive performance and line drawn power quality. The input current total harmonic distortion is observed within a limit of a standard.

Short switch fault diagnosis method for power converter using a model‐based approach in switched reluctance motor drives

Switched reluctance motor (SRM) is a competitive solution for aircraft and automotive applications due to its fault-tolerant capabilities and robust configuration. Power converter is a key component in SRM drives, but it prone to faults. In this study, a new and fast diagnosis method for short-circuit fault of the SRM converter is proposed based on the mixed logical dynamic (MLD) model and residual generation. Effects of short-circuit fault on SRM drives are analysed in detail. The MLD model of an asymmetrical half-bridge converter of SRM drives is presented to evaluate the currents of the power converter. The short-circuit faulty switch is identified by analysing the system residual, achieved by comparing the outputs of the MLD model and the sensor measurements. In contrast to other methods, the presented method requires no additional hardware but only measured phase currents and command signals, which are available in the control system. Simulation results confirm the effectiveness of the proposed diagnosis method. It is shown that such diagnosis method can identify the faulty switch of the power converter in a few milliseconds, which is important to avoid catastrophic consequences. It is fast, reliable and easy for industrial applications due the low-computational requirement.

Generalised fault diagnostic method for power transistors in asymmetric half‐bridge power converter of SRM drive

This study presents a generalised fault diagnosis method for power transistors in the asymmetric half-bridge power converter of switched reluctance motor (SRM) drive. In order to extract the remarkable fault features, three current sensors are rearranged. Each phase current can be calculated by solving the equations associated with the detected values of three current sensors and three coefficients obtained based on different switching states. Different faults are preliminarily detected by monitoring the error between the estimated bus current and the actual bus current. After the identification of fault occurrence, the error will be calculated with all the combinations of three coefficients. The minimum error will be found and the corresponding coefficients are recorded. The fault types and fault power transistors are located by comparing the actual coefficients with the recorded coefficients. Being different from the existing methods, the developed diagnostic strategy can detect multiple fault types and can be used in different control modes, including voltage pulse width modulation, current chopping control and angular position control schemes. Moreover, the proposed technique is easy for online implementation without extra sensors and additional electric devices. The effectiveness of the proposed solution is validated on a three-phase 12/8 SRM drive.

A Switched Reluctance Motor Drive Based on Quasi Z-Source Converter With Voltage Regulation and Power Factor Correction

Modified quasi Z-source converter (MQZSC) is presented in this paper as a front end converter for the switched reluctance motor (SRM) drive system in order to perform voltage regulation and power factor correction (PFC). Using the MQZSC, magnetization voltage is increased and regulated according to the operation modes and requirements of the drive system; therefore, more power is transferred to the motor in each stroke. The demagnitization port is also decoupled from the magnetization port and boosted further to reduce demagnetization time. The proposed converter like conventional SRM converter has the freewheeling mode of operation. The peak current control (PCC) PFC is integrated into the control system of the front-end converter to reduce total harmonic distortion and enhance the power factor. Also, an angle control is implemented in the SRM drive system to reduce the torque ripple alongside voltage regulation in the front end controller. A software simulation is done to verify the proposed drive system. To demonstrate the abilities of the proposed drive system in practice, an experimental setup is devised in the laboratory to verify the simulation results.

Design and Development of Low Torque Ripple Variable-Speed Drive System With Six-Phase Switched Reluctance Motors

Switched reluctance motor (SRM) drives conventionally use current control techniques at low speed and voltage control techniques at high speed. However, these conventional methods usually fail to restrain the torque ripple, which is normally associated with this type of machine. Compared with conventional three-phase SRMs, higher phase SRMs have the advantage of lower torque ripple: To further reduce their torque ripple, this paper presents a control method for torque ripple reduction in six-phase SRM drives. A constant instantaneous torque is obtained by regulating the rotational speed of the stator flux linkage. This torque control method is subsequently developed for a conventional converter and a proposed novel converter with fewer switching devices. Moreover, modeling and simulation of this six-phase SRM drive system has been conducted in detail and validated experimentally using a 4.0-kW six-phase SRM drive system. Test results demonstrate that the proposed torque control method has outstanding performance of restraining the torque ripple with both converters for the six-phase SRM, showing superior performance to the conventional control techniques.

PFC‐based half‐bridge dual‐output converter‐fed four‐phase SRM drive

This study proposes a power factor correction (PFC)-based half-bridge dual-output converter-fed switched reluctance motor (SRM) drive for home appliances. The proposed converter provides two equal output voltages to feed a mid-point converter of a four-phase SRM. An adjustable speed drive is proposed here such that the speed control is obtained by regulating converter output voltage. The converter is operated in discontinuous conduction mode to obtain inherent PFC at supply side. The sensors requirement is reduced by selecting a voltage follower approach. The performance of proposed drive is evaluated for steady-sate and dynamic conditions. The input current total harmonic distortion is reduced below 5% as per an IEC standard.

An Asymmetric Three-Level Neutral Point Diode Clamped Converter for Switched Reluctance Motor Drives

An asymmetric three-level neutral point diode clamped converter for switched reluctance motor drives is proposed in this paper. The modulation method, the dc-link voltage balancing algorithm, and the current control scheme of this converter are presented. The proposed three-level converter is compared with the conventional two-level asymmetric half-bridge converter in terms of cost, current ripple, noise, and power losses. Compared to the conventional two-level converter, the proposed three-level converter has much lower current ripple, lower noise, and higher efficiency. The effectiveness of the proposed converter is verified by both simulation and experimental results.

Design and Simulation of PFC Converter for Brushless SRM Drive

In most of the industrial applications, Switched Reluctance Motor (SRM) is mainly employed due to the reasons like having low maintenance and high efficiency. SRM consists of windings only on its stator, but would not have any windings on rotor thus having very simple construction. The available supply is AC. But AC cannot be directly supplied to SRM when used for air-conditioner application which is employed in this paper. Also power factor in the system needs to be corrected when using a SRM drive. Thus AC supply is fed to power factor correction (PFC) converter which is Buck-Boost converter here in this paper. The output of the PFC converter is fed to SRM through a simple asymmetrical converter. This PFC circuit consists of a simple diode bridge rectifier with Buck-Boost DC-DC converter. A suitable control circuit was proposed to control the input power factor under various loading conditions. This paper gives analysis of SRM drive for air-conditioner application with Buck-Boost converter based PFC circuit. A Matlab/simulink based model is developed and simulation results are presented. Simulation is carried out for different speed response.