Capacitor Motor Research Articles

Performance Analysis of a Single Phase Induction Motor For Different Values of Running Capacitor

The effect of the value of running capacitor on the performance of a single-phaseinduction motor is studied through the evaluation of the efficiency, power factor andvibration of the machine for different values of this capacitor choosing unsuitable value ofthe running capacitor worsen the performance of the motor and it may even damage themotor as a consequence of increasing auxiliary winding current.In this research, a computer program has been developed for finding an optimumrunning capacitor for the induction motor.Experimental results has been obtained in the laboratory and compared with thecomputer results for validation. The effect of the running capacitor on motor vibration hasalso been obtained and measured. Although this study was performed on a certain twophaseinduction motor, the same developed computer program may be used to obtain theoptimum value of the running capacitor for any single phase IM of known parameters.

Performance Analysis of a Single Phase Induction Motor

The effect of the value of running capacitor on the performance of a single-phase induction motor is studied through the evaluation of the efficiency, power factor and vibration of the machine for different values of this capacitor choosing unsuitable value of the running capacitor worsen the performance of the motor and it may even damage the motor as a consequence of increasing auxiliary winding current. In this research, a computer program has been developed for finding an optimum running capacitor for the induction motor. Experimental results has been obtained in the laboratory and compared with the computer results for validation. The effect of the running capacitor on motor vibration has also been obtained and measured. Although this study was performed on a certain two-phase induction motor, the same developed computer program may be used to obtain the optimum value of the running capacitor for any single phase IM of known parameters.

A Novel Ultrasonic Motor Driver Based on Two Phase PWM Signals

An ultrasonic motor (USM) has been widely used in many applications since it has several advantages over the conventional electromagnetic motor, such as high torque at low speeds, no electromagnetic interference, and high holding torque without power supply. However, in order to achieve high efficiency, its electrical drive system presents unique challenges, especially in producing two-phase signal (high frequency, high voltage, phase difference of two-phase signal) input to a low impedance capacitive motor. In this paper, a novel drive system based on microcontroller (ATmega16) has been proposed for ultrasonic motor. Drive system includes power drive circuit and control system. Power drive circuit is combined from Push-Pull Inverter to provide high-frequency two-phase voltages. A microcontroller was used to control ultrasonic motor drive system. PWM signals were generated and then directly applied to the MOSFET drivers for speed control of ultrasonic motor. The frequency and phase difference of two phase PWM signals can be directly changed by microcontroller. Detailed experimental results are provided to demonstrate the successful of the proposed drive system.

Improvement of capacitor induction motor efficiency by using 3-Dimensional finite element method

In this paper, we analyze the steady state characteristics o f an experimental capacitor motor by 3-D non-linear FEM coupled with the voltage equation. Next, we propose several methods to improve the motor efficiency by considering the flu x density distribution. The motor model where the rotor bars are spread inside can improve the motor efficiency by 4.7%.

Amplitude Control of Single Phase Capacitor Motor

The method is proposed to study the performance of single-phase capacitor motor with amplitude control. This is clearly shown by controlling the speed of the motor with varying the applied voltage to the control voltage while the excitation voltage is constant. The obtained results show the validity of the method and the accuracy of the equations derived in this work

Mathematical model of induction capacitor motors with solid ferromagnetic rotors of composite material

Problems of mathematical modeling the induction capacitor motors with the solid ferromagnetic rotor made by powder metallurgy methods are considered. The method of the solution of the two-dimensional field problem with the use of the fast Fourier transformation is presented. The results of the solution of the problem and the analysis of the obtained results are given.

Laser printing of multi-layered polymer/metal heterostructures for electronic and MEMS devices

A laser forward transfer technique for the simultaneous printing of polymer/metal stacked micro-laminates is introduced. Several different material combinations as well as stacking architectures are presented including single laser pulse deposited dual layer capacitors, three-layer stacks for potentially printing organic thin-film transistors (OTFTs), and photo-definable polymer/metal laminates and free-standing membranes for MEMS based sensors.

Prediction of local instabilities in open‐loop induction motor drives

PurposeThe purpose of this paper is to propose an analytical method for prediction of self‐sustained oscillations that might happen during low‐cost induction motor drive application. This forecast is needed to avoid unwanted oscillations that can be encountered for in fan, compressor and pump drives utilizing open‐loop frequency‐controlled three‐phase induction motor drives.Design/methodology/approachThe paper presents the model of the induction motor drive system that includes inverter switches dead‐time and allows discontinuous current of front‐end rectifier. Stability analysis of proposed model was performed by tracing the eigenvalues of the overall system matrix.FindingsDiscontinuous rectifier current at light loads and the dead‐time of the inverter switches are the main sources of undesired low‐frequency self‐sustained speed oscillations in open‐loop controlled induction motor drives. The evaluated risk prediction is a function of drive and motor parameters and load level.Originality/valueThe proposed induction motor drive system model highlights the direct connection between the self‐sustained speed oscillations and the system parameters like inverter dead time, dc capacitor values, motor parameters and motor load level. Good accuracy of instability prediction is verified by dynamic simulation and by extensive experimentation.

A Method of Estimating Loss in a Capacitor Motor Based on Reluctance Network Analysis

We investigated the improvement in characteristics of a capacitor motor wedged with soft ferrite materials to conserve the electrical energy consumed by induction motors. However, a method of estimating the loss in a capacitor motor is necessary to obtain an optimum design for a motor with magnetic wedges. Consequently, we propose a reluctance network analytical (RNA) model that we used to estimate the loss in the capacitor motor. The no-load characteristics, load characteristics, and characteristics with the locked rotor were calculated based on the RNA model, and we estimated the equivalent winding resistance of the rotor for the equivalent circuit model of a capacitor motor.

Performance Improvement of Z-Source Inverter-Fed Induction Motor Drives Using Modified Voltage Space Vector

In traditional Z-source inverter (ZSI) fed induction motor drives, the Z-source capacitor voltage and the motor terminal voltage are controlled by the shoot-through duty ratio and the modulation index, respectively. Modified voltage space vector has been proposed to improve motor terminal voltage control with effective DC boost in the DC link. For the same shoot-through duty ratio, modified voltage space vector provides better voltage boost in the DC link with reduced harmonics in the load side than the traditional voltage space vector. This paper presents an integrated control technique to minimise the electromagnetic torque ripples in the rotor of the ZSI-fed induction motor drives using modified voltage space vector. To improve the stability of the overall drive system, the motor terminal voltage alone is sensed instead of sensing the Z-source capacitor voltage and motor terminal voltage independently. This provides a single-stage controller for motor drive systems. The proposed induction motor drive system provides a better ride-through capability during voltage sags, better line harmonic profile, and minimisation of the torque ripples in the rotor. The proposed control technique is simulated using MATLAB/Simulink software, and analysis and experimental results have been presented to validate them.

A Study of Influence of Configurations of the Windings on the Performance of Single Phase Induction Motor with Capacitor Start

The single phase induction motors needs two stator windings to produce rotating magnetic field : one main winding and the other auxiliary winding. The aim of the auxiliary winding is to create the rotating electromagnetic field when the machine is started-up and is afterwards turned off, generally through the centrifugal switch coupled together with the shaft of the machine rotor. The main purpose of this document is to evaluate the influence that the two windings have on the external characteristics of the single phase induction motor . For this purpose , two different kinds of windings were carried out and simulated, with the proposal to obtain some benefits. The main winding and the auxiliary winding were prepared and mounted on a prototype. The simulation was done via software based FEM , to make the extraction and results analysis possible. This results are shown at the end this document.

コンデンサモータの負荷時電磁振動に及ぼすスロット数組合せおよび斜めスロットの影響

The capacitor motor (CRM) is widely used to drive industrial equipments and electric home appliances. Recently, the reduction in the vibration and noise of the CRM has become increasingly important from the standpoint of environmental improvement. However, the electromagnetic vibration of the CRM under load has not been analyzed sufficiently. Therefore, we have studied the electromagnetic vibration of CRM for the purpose of reducing it. In a previous paper, the relationships for a backward magnetic field, the equivalent circuit current, and the vibration of the CRM were clarified. The present paper theoretically and experimentally discusses the effect of the slot combination and skewed slot on the electromagnetic vibration of CRM under load. The primary conclusions are as follows:(1) In the case of 4-pole and 6-pole CRMs, the dominant electromagnetic vibration of CRMs was theoretically attributed to three types of electromagnetic force waves. Two types of electromagnetic force waves are generated: one wave is generated by the interaction of two forward magnetic fluxes, such as those of a three-phase squirrel-cage induction motor, and the other wave is generated under the influence of a backward magnetic flux.(2) The characteristics of dominant electromagnetic vibration depending on load and running capacitor were classified theoretically and experimentally into three types based on the characteristics of the electromagnetic force wave and equivalent circuit current.(3) The influences of magnetic saturation in dominant electromagnetic vibration were verified experimentally and their causes were clarified theoretically in relation to electromagnetic force waves.

단상 유도전동기의 전자식 기동장치 개발

본 논문에서는 단상 유도전동기의 전자식 기동장치 개발에 관해 연구하였다. 전자식 기동장치는 콘덴서 기동형 단상 유도전동기의 보조권선 회로에 장착된 원심력 스위치를 대체하기 위해 활용된다. 개발된 전자식 기동장치는 보조권선의 전압을 관측하여 전동기가 정격속도에 가까워지면 보조권선을 전원으로부터 개방하는 역할을 수행한다. 범용 단상 유도전동기에 사용되고 있는 원심력스위치는 기계식 접점을 사용하기 때문에 접점에서 불꽃이 발생하고 전동기의 수명과 신뢰성을 저감시키는 요인이 된다. 개발된 전자식 기동장치는 무접점 반도체 스위치인 트라이악을 적용함으로써 전동기의 신뢰성과 특성이 개선될 수 있으며, 저전압 및 반복실험 등의 다양한 실험을 통해 신뢰성을 검증하였다.

A new driver based on dual-mode frequency and phase control for traveling-wave type ultrasonic motor

A mode conversion rotary traveling-wave ultrasonic motor (TWUSM) has potential applications in miniature robotics. However, its electrical drive circuit presents unique challenges, particularly in producing a high frequency (about 40 kHz), high voltage (400 V peak-to-peak) signal input to a low impedance capacitive motor, while achieving high efficiency. A novel driving circuit is proposed to provide two-phase balance voltage for a TWUSM. This paper describes the design of TWUSM drive circuit, intended for simultaneously employs both the driving frequency and phase modulation control scheme. The operating principles and a detailed analysis of the proposed driving circuit, consisting of voltage-controlled oscillator (VCO), voltage-controlled phase-shifter circuit and power amplifier circuit, are introduced. To drive the USM effectively a two-phase power amplifier converter using non-resonant technique was designed to provide a balanced two-phase voltage source, and the two-phase output driving voltages could be maintained at the same peak voltage value at the driving frequency under varying phase-modulation processes. Detailed experimental results are provided to demonstrate the effectiveness of the proposed driving circuit.

217 機能モデルによるスマート構造のエネルギー回生振動制御のシミュレーション

Recently smart structures using piezoelectric elements as sensors and actuators of vibration control have been studied. Design and analysis of such smart structure is a multidisciplinary problem that consists of mechanical, electrical and control problem. Therefore, multidisciplinary modeling technique is desired for study of smart structure. However, conventional model of mechanical system is incompatible with model of electrical system. Block diagram can model mechanical and electrical system in generalised form. However physical quantities are treated just as signals and it is not easy to understand physical phenomenon from signal flow in block diagram. Functional model is proposed as a modeling method of multidisciplinary system and can solve the above mentioned problems of conventional models. Functional models of basic elements of mechanical and electrical system, for example, mass, stiffness, capacitor, inductor and DC motor have been developed. However, functional model of piezoelectric element has not been developed. In this paper, functions of piezoelectric element are considered and functional model of piezoelectric element is developed to apply functional model to smart structure system. Energy flow in the energy regenerative vibration control system that have been studied by authors is simulated by functional model and the result is compared with the result of the previous simulation using equivalent circuit model.

1322 機能モデルによる圧電素子のモデル化(J14-5 知的材料・構造システム(5) 圧電素子とその応用,ジョイントセッション,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

Recently smart structures using piezoelectric elements as sensors and actuators of vibration control have been studied. Design and analysis of such smart structure is a multidisciplinary problem that consists of mechanical, electrical and control problem. Therefore, multidisciplinary modeling technique is desired for study of smart structure. However, conventional model of mechanical system is incompatible with model of electrical system. Block diagram can model mechanical and electrical system in generalised form. However physical quantities are treated just as signals and it is not easy to understand physical phenomenon from signal flow in block diagram. Functional model is proposed as a modeling method of multidisciplinary system and can solve the above mentioned problems of conventional models. Functional models of basic elements of mechanical and electrical system, for example, mass, stiffness, capacitor, inductor and DC motor have been developed. However, functional model of piezoelectric element has not been developed. In this paper, functions of piezoelectric element are considered and functional model of piezoelectric element is developed to apply functional model to smart structure system.

Determination of the effective permittivity of dielectric mixtures with the transmission line matrix method

In this article, the effective permittivity of two-phase dielectric mixtures is calculated by applying the transmission line matrix (TLM) method. Two slightly different TLM algorithms are considered: a hybrid approach, which combines the TLM method with a subgriding technique based on dual capacitor circuits, to allow a refined description of the material, and a standard or pure TLM approach, which uses a mesh size smaller than the typical dimension of insertions in order to appropriately describe details of the geometry. A study of the statistical distribution of permittivity for insertions in random positions is also presented, showing that the effective permittivity of the mixture tends to concentrate around the mean value as insertions reduce in size. Both TLM techniques are applied to dielectric mixtures in two-dimensional situations. When the concentration of insertions is small, the results are in close agreement with prediction formulae while for higher concentration values, deviations are observed, although basically the results fall within the range predicted by theoretical bounds. Numerical results obtained using the two TLM approaches present a similar qualitative behavior; nevertheless, a clear difference is observed between them. The study of special periodic situations with coated insertions allows us to identify the pure TLM results as more accurate than those of the hybrid approach and also explains why homogeneous distributions provide numerical values close to the theoretical limits. The effects of shape on permittivity are also modeled and deviations to the Wiener bounds are discussed in detail, using two- and three-dimensional examples in practical situations.

Optimization of monophase asynchronous electrical motors with an unsymmetrical three-phase stator winding

Mathematical models of single-phase induction motors with asymmetric three-phase and two-phase windings (the number per pole in the main and auxiliary phases is not the same in the latter case). The models allow one to take into account during computations the torques created by higher harmonic fields. Criteria for the optimization of electrical motors are selected and optimization studies of induction capacitor motors are conducted on the basis of the main version of a modern unified series. Opportunities to improve energy performance are shown

Ｅｗ｀２´によるコンデンサモータの負荷時における高調波損失推定に関する一考察

Reduction of the iron loss and copper loss of induction motors has been thoroughly studied in a conventional sense. However, the fact that no method for estimating the harmonic loss due to the materials or dimensions of a motor has yet been established, has been an obstacle to harmonic loss reduction. We proposed an evaluation index Ew2 for the harmonic loss that is caused by slots of a capacitor motor, which is a kind of a single-phase induction motor. Ew2 is calculated from effective value of electromotive force with a virtual coil of the rotor surface. On no load, we found that Ew2 was effective as an evaluation index for the harmonic loss. In this paper, we calculate Ew2 on load and examine the propriety of using Ew2 as a harmonic loss evaluation index.

Critical Slip and Characteristics of Induction Motor for Borehole Investigating Devices

If the borehole medium temperature did not exceed +2000C, it is successfully used single-phase asynchronous capacitor motor with solid ferromagnetic rotor for the borehole investigating device drive. For the boreholes of which medium temperature exceeds +2000C it is expedient to use two-phase or three-phase induction motor with solid ferromagnetic rotor. There are presented the critical slip and maximum electromagnetic power expressions of the symmetric induction motor with solid ferromagnetic rotor taking into account the inner complex impedance of the power-supply source and the distributed parameters of the long geophysical cable. It has been proved that derived critical slip expression is the general case of a critical slip formula. The algorithm for the study of motor characteristics taking into account the parameters of the equivalent and the supply circuits is presented. Developed program gives possibility to compute the motor characteristics when it is placed in any borehole depth at various environment and borehole medium temperatures. Ill. 4, bibl. 4 (in English; summaries in English, Russian and Lithuanian.).