PWM Motor Research Articles

Experimental Research on Regenerative Braking of Wheel-Hub Motor

The factors affecting regenerative braking performance of brushless DC motor(BLDCM) were analyzed by means of bench test and road test .the BLDCM was used as drive motor in a four –wheel-independent-drive EV. The relation between PWM duty and motor rotation speed, charging current and voltage were determined by test, which can benefit design of control strategy of regenerative braking for electric motor and help to improve energy efficiency.

The windmill topology

In this article, an improved three- to nine-phase windmill 18- pulse clean power ASD system is presented. A novel third harmonic circulating current calculation method is introduced and used to investigate different topologies. A system evaluation demonstrates the steady state and dynamic performance of a complete rectifier and PWM motor drive.The state-of-the-art simulation is built on the complete system consisting of the utility source, windmill nine-phase autotransformer, nine-phase rectifier bridge, DC link capacitor, inverter with SVPWM, and induction machine with load.

Perfect wave oscillation suppression with reflection coefficients adaptation in PWM motor drives with long feeding cables

A perfect wave oscillation cancellation scheme is a proposed method for suppressing overvoltage in adjustable speed PWM motor drives through long feeding cables. It is a new solution to the overvoltage problem, which cascades the proposed filter with the transmission line achieving a pure delay transfer between inverter and motor, completely removing the pulse reflection that causes the overvoltage problem. Simple voltage transfer function with time delay is derived under a distortionless transmission assumption, which is valid in practice. The proposed PWM input voltage form is calculated by inverting the voltage transfer function. Also, the unknown reflection coefficients are identified through a simple adaptive algorithm. The simulation results verify the performance of the proposed method, which is compared with a previous method.

Fault detection of open-switch damage in voltage-fed PWM motor drive systems

This paper investigates the use of different techniques for fault detection in voltage-fed asynchronous machine drive systems. With the proposed techniques it is possible to detect and identify the power switch in which the fault has occurred. Such detection requires the measurement of some voltages and is based on the analytical model of the voltage source inverter. Simulation and experimental results are presented to demonstrate the correctness of the proposed techniques. The results obtained so far indicate that it is possible to embed some fault-tolerant properties for the voltage-fed asynchronous machine drive system.

Using computer simulations to analyze electromagnetic emissions generated in PWM inverter and motor drive systems

Electromagnetic wave emissions generated from PWM inverter and motor drive systems are rapidly increasing as switching characteristics of power switching devices used in PWM inverters are increased, and as operating frequencies of microcomputers in the motor drive controllers are also increased This paper discusses emission characteristics generated due to common mode noises which are produced by circuits having with stray capacitances between the PWM inverter frame and the motor frame. It is difficult to cope with reduction of common mode noises emissions in comparison with other differential mode noises. The emissions are analyzed by computer simulations using the method of moments, especially, for the case of emissions connected to the PWM inverter frame and motor frame by a conducting plate. The effects of cable length between the PWM inverter and motor on emissions is also examined In low frequency regions where the structure length of the drive system compromised of the PWM inverter and the motor is less than one-fourth of the electromagnetic wavelength, emissions are remarkably reduced by using a conducting plate between the PWM inverter and the motor. In high frequency regions there is hardly any reduction in emissions. Finally, the resonance phenomenon is shown to occur when cable length between the PWM inverter and the motor is equal to one half of the electromagnetic wavelength.

Signal based approaches to fault detection in electrical drives

This paper presents a signal based approach to detect PWM inverter faults and motor unbalances in electrical drives. A diagnostic system which uses the control variables of the drive and the current measurements is presented. It is based on frequency analysis and on the energetic characterization of these variables in the PWM frequency domain. These method very simple to implement in real time have been successfully applied to an experimental system.

PWM inverter and motor applications: a quick reference of bibliographies and abstracts

The purpose of this paper is to provide the reader with a quick reference to some of the more recently published technical papers dealing with the application of PWM inverter-fed motor systems. It should be pointed out that the "system" includes all components between the incoming 60 Hz power supply and the driven equipment. There are literally hundreds of technical papers to choose from in preparing such a reference. The authors have selected the more recent publications. The technology associated with the newer PWM drives is changing so fast that many of the papers published from five to ten years ago may be effectively obsolete. No attempt has been made to evaluate the technical merits of each work, nor do the authors claim that the reference is even close to being all-inclusive. However, it is a start, and should help the reader in addressing some of the key issues that must be dealt with to assure a successful implementation. These papers are categorized as follows: (1) motor/drive system application issues; (2) dv/dt, reflected wave and lead length issues; and (3) motor issues.

Application issues for PWM adjustable speed AC motor drives

In this article, some application issues for adjustable speed AC motor drives have been investigated. The effects of high PWM frequency, or high dv/dt on the motor terminal voltages and bearing currents have been addressed and explained. Mitigation techniques have been shown to significantly reduce the transient peak voltage and dv/dt at the motor terminals, as well as within the motor windings. This reduction contributes to improved reliability of PWM motor drive systems.

Fuzzy Based Sliding Mode Control of Permanent Magnet Brushless DC Motor

A fuzzy based sliding mode control scheme for permanent magnet brushless dc (PMBDC) motor drive system is proposed. It combines the best features of both the fuzzy logic and sliding mode control to achieve rapid and accurate control of a PMBDC motor drive. The chattering encountered by most of the sliding mode control scheme is greatly alleviated without sacrificing its invariant properties. The basis for the selection of switching lines and control gains in the sliding mode controller are given. The model of the system consisting of fuzzy sliding mode controller (FSMC), reference current generator, PWM current controller, inverter and motor is developed for studying the dynamic behavior of the complete drive system. The study also examines the effectiveness of the controller for operation of the motor under the condition of load perturbation and speed reversals.

Servo-drive systems for milling machine retrofit application

The objective of this paper is to describe how to retrofit a traditional milling machine, which has the hand wheel-manipulated ladder lead screw transmission system, with a d.c. servo-drive system. In this research, a d.c. servomotor is used as the actuator instead of the hand wheel to operate a milling machine table. A PC/AT is used to handle the data acquisition and the control signal calculation for various types of motion condition. The control laws are designed and written as C language software programs. In order to reduce the cost of the approach given in this study, the new type of low-cost PWM motor driver, and position and velocity feedback circuits are all designed and implemented. Additionally, a classical PID control method with relay adjustment is used to design the controller for this converted system in order to verify the approach availability. Finally, the system output response and the controller performance are investigated based upon the experimental data of this milling machine system operating in different specified motion situations.

Novel PWM controlled series-connected current-source inverter drive

A novel current-source inverter (CSI) drive is presented consisting of three single-phase CSIs connected in series. It is shown that this series-connected CSI (SCCSI) can be viewed as the dual of the three-phase full-bridge voltage-source inverter (VSI), and therefore incorporates all the flexibility needed to generate any 3-level PWM motor stator current with 180° conduction patterns. As a result of the increased flexibility of the SCCSI circuit topology, it is demonstrated how more sophisticated PWM switching strategies can be generated which considerably improve the drive performance at low operating speeds. The SCCSI drive performance is investigated for both quasi-square wave and PWM operation, including harmonic elimination and minimisation PWM switching strategies, and it is compared with both the conventional CSI and Duplex CSI drive performance. Both computed and experimental results obtained from a microprocessor-controlled SCCSI drive are presented, which confirm the superior low speed performance of the SCCSI drive, thereby extending the viable range of operation of the CSI drives.

ソフトウエア化磁束制御形ＰＷＭ制御と誘導電動機駆動特性

ソフトウエア化磁束制御形ＰＷＭ制御と誘導電動機駆動特性