C-dump Converter Research Articles

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.

Performance of Proposed Resonant C-dump Converter in Switched Reluctance Motor Drive

The speed at which switched reluctance motors (SRMs) make transitions from chopping control to single pulse operation (i.e., low-speed to high-speed operation) is unsatisfactory for realizing optimum performance at all operational regimes. In this paper, we improve the operational performance of SRMs using the current hysteresis control method, which is able to maintain a generally flat current waveform. At high speeds, the current-chopping capability is lost because of the development of the back-EMF. Therefore, SRMs operate in single pulse mode. By using the zero-current switching and zero-voltage switching techniques, the stress of power switches can be reduced in the chopping mode. When the commutation changes from one phase winding to another phase winding, the current can become zero rapidly in this period because a negative DC-source voltage is produced several times in the phase winding. In this paper, we compare the performance based on the energy-efficient C-dump converter topology and the proposed resonant C-dump converter topology. We present simulation and experimental results to verify the effectiveness of the proposed circuit.

Rotor vibration control of hybrid pole bearingless switched reluctance motor with C-dump converter

Rotor vibration control of hybrid pole bearingless switched reluctance motor with C-dump converter

Rotor vibration control of hybrid pole bearingless switched reluctance motor with C-dump converter

Rotor vibration control during start up, acceleration and deceleration phases is one of the key problems besides stable levitation, in high-speed applications of bearingless switched reluctance motor (BSRM). In this paper, an effective intelligent sliding mode controller is proposed for suppressing the rotor vibration due to residual unbalance and external disturbance during levitation and motoring phases. The parameters of time-varying sliding surface for avoiding high control gains and chattering are adjusted integrating the sliding mode control (SMC) and features of fuzzy logic control. The experimental studies conducted on a prototype BSRM system confirm that the application of fuzzy SMC guarantees the robust performance with less chattering under model uncertainties and unknown external disturbances compared to classical sliding mode controller.

C-Dump Converter Design and its Dynamic Analysis in Simulink Environment for a Switch Reluctance Machine

It is an analysis of asymmetric converters used to drive switched-reluctance motors (SRM). Usually, two switches per phase exist in these converters, therefore the cost of converter rises up. The energy recovery chopper in a capacitor-dump (C-dump) SRM drive which needs one more additional switch than the number of phases is analyzed, designed and discussed. The converter allows continuous output current operation. The dynamic behavior of the chopper shows that it operates as a boost DC-to-DC converter in a regenerative mode. In this study, A 6/4 SRM for both no motor phase current control applied and controlled at 8A phase current (C.C.), the characteristics of C-dump converter voltage (Vc), current (ig) and phase voltages applied to the motor windings are examined in Matlab-Simulink environment.

Control of SRM with Modified C-dump Converter in Cooling System of Automobiles

Control of SRM with Modified C-dump Converter in Cooling System of Automobiles

전동차 출입문 구동을 위한 SRM용 C-dump 컨버터 Topology 특성 비교

전동차 출입문 구동을 위한 SRM용 C-dump 컨버터 Topology 특성 비교

A Novel Inverter Topology for Brushless DC Motor Drive to Shorten Commutation Time

Commutations existing in a brushless dc motor (BLDCM) drive system not only aggravate the torque ripple and reduce the power factor but also cause the catastrophic failure of a sensorless drive based on the zero-crossing detection of back electromotive force when the commutation duration approaches or exceeds 30 electrical degrees. For a sensorless BLDCM drive system with a long commutation time, it is necessary to shorten the commutation time. In this paper, a technique making the commutation time significantly reduced by means of a novel inverter topology is presented. The proposed topology is based on the idea of supplying higher dc-link voltage for the freewheeling phase. First, the dc link of the backward freewheeling path is decoupled from that of the forward energy flow path. The superiority of dc-link decoupling for commutation control is analyzed. Then, in order to provide adjustable voltage higher than the dc source voltage for the dc link of the freewheeling path, a double-layer C-dump converter is proposed. Compared with the traditional unipolar C-dump converter, it not only upraises the potential of the positive rail but also lowers the potential of the negative rail. Finally, the proposed inverter topology is verified by simulation and experimental results.

Development of the C-dump topology-based four-level converter for switched reluctance motor drives

Demand for brushless and commutator-less motor drives is increasing day by day for industrial applications. So improvement in switched reluctance motor (SRM) drives remains an important research area due to cheap and maintenance free motor construction. In literature, various converter topologies and their control strategies are described, however the C-dump-based converter topologies have gained interest owing to its ability to retrieve the stored magnetic energy. This can be further utilised to achieve desirable performance characteristics. The paper addresses the development of a drive system for a four phase, 8/6 switched reluctance motor. The drive system consists of a power circuit and its control scheme. The power components are designed for a 4-phase, 3 hp, 8/6 SRM which is used to obtain the experimental results. A simple PI-based speed control scheme is implemented which is suitable for low power applications such as cooling fan, blower, etc. A C-dump-based converter is proposed which allows reduction of switching losses, especially in the low speed range and it eliminates energy intake from the source during energy discharge process.

Regeneration Using C-Dump Fed Switched Reluctance Generator

The regeneration modes of switched reluctance machines are examined in this paper. The conversion of mechanical energy to electrical energy is aided by the stator excitation which is used to provide the air-gap flux and recover the energy from a prime-mover making it suitable for electric/hybrid vehicles. The operation of a C-Dump converter in the generation mode is analyzed and the energy recovery mechanism is illustrated using MATLAB simulations. The braking profile on the prime mover is also examined for multiphase excitation with various currents. The excitation reference is the control variable that is dynamically adjusted to achieve control in the braking mode. A control law is derived to achieve a target speed in the braking mode.

A MODIFIED C-DUMP CONVERTER FOR PMSM MACHINE USED IN A FLYWHEEL ENERGY STORAGE SYSTEM

This paper presents a modified C-dump converter for permanent magnetic synchronous (PMSM) machine used in the flywheel energy storage system. The converter can realize the energy bidirectional flowing and has the capability to recover the energy extracted from the turnoff phase of the PMSM machine. The principle of operation, modeling, and control strategy of the system has been investigated in the paper. Simulation and experimental results of the proposed system are also presented and discussed.

Four-quadrant control of C-dump converter-fed PMBDC motor drive system

This paper presents the operational and design characteristics of the C-dump converter-fed permanent-magnet brushless DC motor (PMBDCM) drive for four-quadrant performance. The C-dump converter, which has one switch per phase, is present for use in the control of a PMBDCM. The drive system is analyzed and design guidelines to develop for the given PMBDCM ratings. The input power factor correction (PFC) is applied to the developed C-dump converter-fed PMBDCM drive. Experimental results from a laboratory prototype are presented to validate the feasibility of the proposed PMBDCM drive system. The predicted and measured overall system efficiencies are presented with and without PFC circuit.

A Modified C-Dump Converter for BLDC Machine Used in a Flywheel Energy Storage System

This paper presents a modified C-dump converter for brushless DC (BLDC) machine used in the flywheel energy storage system. The converter can realize the energy bidirectional flowing and has the capability to recover the energy extracted from the turnoff phase of the BLDC machine. The principle of operation, modeling, and control strategy of the system has been investigated in the paper. Simulation and experimental results of the proposed system are also presented and discussed.

Control of c-dump converters fed switched reluctance motor on an automotive application

This paper deals with the analysis of switched reluctance motor drives for different drive circuit topologies used in automobile. Therefore, we attempt to improve the weaknesses associated with the asymmetric bridge converter in the limited internal environment of automotive application. Two kinds of c-dump converters are tested in terms of dump capacitor voltage, speed response according to the variation of advance angle and efficiency for the radiator cooling-fan drive of an automobile. They enable more economical and efficient converter topology for automobile industries. This paper describes the performance characteristics of 12 V–250 W–3000 rpm SRM drives for automobiles. Computer simulation and experiment results are then presented to verify the performance of the two kinds of c-dump converters.

Single Chip Integration for Motor Drive Converters With Power Factor Capability

In this paper, an innovative converter topology is presented that allows to improve the performance of electronically commutated motor drives, aimed to equip home appliances. The proposed topology is based on a modified C-dump converter configuration, where the energy recovery stage acts as an active power factor controller (PFC) for offline operation. This is made possible by introducing a new technique to manage the free-wheeling energy that is recovered back to the dc bus by a suitable high frequency (HF) transformer. The proposed approach allows to omit the PFC stage that is included in motor drives devoted to home appliance applications in order to comply with power quality requirements. Moreover, the proposed converter topology features only low side or high side configuration switches, allowing to simplify the design of the drive and easily integrate the power semiconductors in a single chip exploiting smart power technologies. Simulations and experimental results confirm the validity of the proposed approach.

Improving performance of switched reluctance motor by fuzzy logic controller

This paper presents torque ripple minimization of a switched reluctance motor (SRM) by using a fuzzy controller. The nonlinear model of the SRM and the mathematical model of the converter circuit are driven. The motor used in both simulation and experiment is an 8/6 four phase SRM with a C-Dump converter. The applied fuzzy controller adjusts the value of the reference current to keep the speed of the motor constant. The results show that the fuzzy logic is effective in reducing the torque ripple of the motor, and compensating for the nonlinear torque characteristics. The experimental result is given for a current control algorithm, and it shows that the quite nonlinear model of the SRM is well defined. Copyright © 1999 John Wiley & Sons, Ltd.

Energy-efficient C-dump converters for switched reluctance motors

Two energy-efficient converter topologies, derived from the conventional C-dump converter, are proposed for switched reluctance motor (SRM) drives. The proposed topologies overcome the limitations of the conventional C-dump converter, and could reduce the overall cost of the SRM drive. The voltage ratings of the dump capacitor and some of the switching devices in the proposed converters are reduced to the supply voltage (V/sub dc/) level compared to twice the supply voltage (2V/sub dc/) in the conventional C-dump converter. Also, the size of the dump inductor is considerably reduced. The converters have simple control requirements, and allow the motor phase current to freewheel during chopping mode. Simulation and experimental results of the converters are presented and discussed.

A modified C-dump converter for variable-reluctance machines

A new type of converter for variable-reluctance-machine (VRM) drives is described. In this converter topology, the energy extracted from an ongoing phase is stored in a dump capacitor. The energy stored is consequently used either to quickly turn on the next ongoing phase or to energize the conducting phase frequently during the conduction interval instead of being returned to the supply as for a conventional C-dump circuit. Since, the additional switch used to pass the energy to the C-dump capacitor is switched under a relatively-low-voltage condition and its switching frequency is relatively low, the rating of the additional switch is modest. The major advantage os this converter is that it uses a low-switching device/phase ratio while achieving better performance characteristics than the other topologies.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Development of a Unipolar Converter for Variable Reluctance Motor Drives

A new converter concept for driving the switched reluctance motor has been developed. This converter has only one switching device per phase, uses a unipolar dc supply, returns all the trapped energy to the source, and does not require bifilar windings; it is called a C-dump converter because the trapped energy is dumped in a capacitor and then returned to the dc source. The topology for several different C-dump converters is presented. In addition, the design and experimental results for a C-dump converter using a chopper to recover the energy dumped on the capacitor are presented.