共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Describes the performance evaluation of a limited-angle torque motor, using a simple piecewise analytical approach to overcome system nonlinearities. A block-diagram model developed from a combination of measurement and manufacturer's data is shown to be capable of accurately predicting both the steady-state and the dynamic performance. The approach described is of valuable assistance in the design of a complex multiloop nonlinear controller that is needed for a drive system containing the motor 相似文献
3.
Probabilistic voltage harmonic analysis of direct torque controlled induction motor drives 总被引:2,自引:0,他引:2
Kaboli S. Vahdati-Khajeh E. Zolghadri M.R. 《Power Electronics, IEEE Transactions on》2006,21(4):1041-1052
In high frequency motor-drives such as direct torque controlled (DTC) induction motor drives, the motor harmonic loss, and electromagnetic interference are largely affected by the spectrum of the motor input voltage. Nonlinear elements in the control loop of DTC drive make harmonic analysis of the drive very complex compared to classical pulsewidth modulated controlled drives. In this paper, a probabilistic method to study the harmonic contents of voltage in DTC of induction motors is presented. The DTC voltage chain is simulated with a random process. Then, the autocorrelation function of voltage vectors is calculated and its power spectrum density is obtained. The effect of flux and torque hysteresis controller bands, machine parameters, and inverter dc-link voltage on the motor voltage spectrum is investigated. Major harmonics in the DTC voltage spectrum are specified and their behaviors are described. Simulation and experimental results are presented to justify the theoretical analysis. 相似文献
4.
Goldenberg A.A. Laniado I. Kuzan P. Zhou C. 《Industrial Electronics, IEEE Transactions on》1994,41(4):461-466
The paper presents a method for controlling switched reluctance motor (SRM) torque for force control applications. SRMs are used in AdeptOne robots, and the authors perform experiments with two robots, controlled in coordination, in grasping and manipulation of various objects. The object and robot parameters are not exactly known, and adaptive methods are used to control the overall system. These methods are model-based control techniques which require high bandwidth torque control. This requirement is typical for high precision mechanisms. SRM characteristics are very nonlinear. In particular the torque ripple, friction, and the torque versus position and current relationships were analyzed in the context mentioned above, and specifically, for force control applications. The proposed method is based on a new commutation algorithm and a measured torque versus position and current relationship, used to smooth the SRM's torque ripple, hence generating a torque output nearly independent of position. Furthermore, the internal friction is estimated on-line, and compensated for. This renders a high accuracy torque tracking. The torque control method is based on feedback from the motor angular velocity, motor angle, armature current, and feedforward for friction compensation and cancellation of nonlinear effects. The method has been tested experimentally on Adept motors and the results were very encouraging. The method has been also used for adaptive control of two coordinated Adept robots 相似文献
5.
In this paper, a novel technique for the direct torque control (DTC) of an induction motor is proposed, which overcomes the trouble of high torque ripple afflicting the conventional DTC technique. With the novel technique, the inverter voltage vector selected from the switching table is applied for the time interval needed by the torque to reach the upper (or the lower) limit of the band, where the time interval is calculated from a suitable modeling of the torque dynamics. By this approach, the control system emulates the operation of a torque hysteresis controller of analog type since the application time of the inverter voltage vector is dictated by the allowed torque excursion and not by the sampling period. It is shown by experimental results that the technique yields a considerable reduction of the torque ripple. A further and ultimate reduction is obtained by compensating for the delay inherent in the discrete-time operation of the control system. The outcome is that the torque ripple of the motor is constrained within the hysteresis band of the torque controller, for a band of customary value. An ancillary merit of the technique is the almost full elimination of the average torque error inherent in the conventional technique. If the hysteresis band is shrunk, the torque ripple is bound to swing out the band limits. Under this circumstance, an extension of the technique is developed, which helps keep the torque ripple at minimum. To assess the characteristics of the proposed DTC technique, the following quantities: average torque error, rms value of the torque ripple, and inverter switching frequency are measured for different stator flux angular speeds and hysteresis bands of the torque and flux controllers. As a comparison, the same quantities are given for the conventional DTC technique. 相似文献
6.
7.
为了验证基于三电平逆变器异步电动机直接转矩控制系统的可行性和有效性,利用Saber仿真软件优良的模块化和分级式的系统仿真能力,建立了异步电动机直接转矩控制系统中定子磁链与电磁转矩观测器、扇区判断、空间电压开关矢量表以及二极管箝位型三电平逆变器等子系统的仿真模型,并根据直接转矩控制原理最终构建了完整的系统仿真模型。利用所构建的系统仿真模型进行了仿真实验,仿真分析结果证明建立的系统模型是有效的,表明直接转矩控制系统具有良好的动态响应性能。 相似文献
8.
9.
10.
Hsin-Jang Shieh Kuo-Kai Shyu 《Industrial Electronics, IEEE Transactions on》1999,46(2):380-389
In this paper, the nonlinear sliding-mode torque and flux control combined with the adaptive backstepping approach for an induction motor drive is proposed. Based on the state-coordinates transformed model representing the torque and flux magnitude dynamics, the nonlinear sliding-mode control is designed to track a linear reference model. Furthermore, the adaptive backstepping control approach is utilized to obtain the robustness for mismatched parameter uncertainties. With the proposed control of torque and flux amplitude, the controlled induction motor drive possesses the advantages of good transient performance and robustness to parametric uncertainties, and the transient dynamics of the induction motor drive can be regulated through the design of a linear reference model which has the desired dynamic behaviors for the drive system. Finally, some experimental results are demonstrated to validate the proposed controllers 相似文献
11.
Yen-Shin Lai Juo-Chiun Lin 《Power Electronics, IEEE Transactions on》2003,18(5):1211-1219
A new hybrid fuzzy controller for direct torque control (DTC) induction motor drives is presented in this paper. The newly developed hybrid fuzzy control law consists of proportional-integral (PI) control at steady state, PI-type fuzzy logic control at transient state, and a simple switching mechanism between steady and transient states, to achieve satisfied performance under steady and transient conditions. The features of the presented new hybrid fuzzy controller are highlighted by comparing the performance of various control approaches, including PI control, PI-type fuzzy logic control (FLC), proportional-derivative (PD) type FLC, and combination of PD-type FLC and I control, for DTC-based induction motor drives. The pros and cons of these controllers are demonstrated by intensive experimental results. It is shown that the presented induction motor drive is with fast tracking capability, less steady state error, and robust to load disturbance while not resorting to complicated control method or adaptive tuning mechanism. Experimental results derived from a test system are presented confirming the above-mentioned claims. 相似文献
12.
In the original paper (Chan et al., see ibid. vol. 37, p. 477-82, 1990), the authors presented results based on the machine parameters of a 1 kW, four-pole induction motor listed in the Appendix. Here, the author discusses what he feels is some confusion regarding the inductance terms and their values. His comments and the original authors' reply are presented 相似文献
13.
Faa-Jeng Lin 《Industrial Electronics, IEEE Transactions on》1997,44(3):398-407
A digital signal processor (DSP)-based permanent magnet (PM) synchronous motor (SM) drive with a proposed recursive least-square (RLS) estimator and real-time integral-proportional (IP) position controller is introduced in this study. First, the rotor inertia constant, the damping constant, and the disturbed load torque of the synchronous motor are estimated by the proposed RLS estimator, which is composed of an RLS estimator and a torque observer. Next, the IP position controller is real-time designed according to the estimated rotor parameters, to match the time-domain command tracking specifications. Then, the observed disturbance torque is fed forward, to increase the robustness of the synchronous motor drive 相似文献
14.
Nakai H. Ohtani H. Satoh E. Inaguma Y. 《Industrial Electronics, IEEE Transactions on》2005,52(3):800-806
Hybrid electrical vehicles and electrical vehicles are being actively developed. A hybrid electric vehicle motor design requires high efficiency, high power/weight ratio, and reliability from low rotor speed to high rotor speed. The permanent-magnet synchronous motor is used in order to fulfill these requirements. The purpose of this paper is to develop a permanent-magnet synchronous motor control method for all rotor speeds. This method increases the torque and the efficiency at high speed when compared to the ordinary current error feedback method. A method composed of two compensators is proposed to achieve this objective. One of the compensators controls the torque using the voltage phases. The other one is the ordinary current error feedback. Several correcting methods for the voltage phase compensator have been proposed for the compensator for many control demands. The validity of the proposed method was confirmed using simulation and experimental evaluations. 相似文献
15.
This paper presents a method of torque measurement in a hybrid stepping motor without the use of speed or position sensors. It is shown that torque ripple can be minimized by appropriate shaping of the phase-current pulses and that efficiency can be maximized when the level of mechanical load applied to the shaft is known. A controller is described which generates a signal related to the mechanical load by observation of the phase-current profile using a novel low-complexity technique. Practical results are presented, showing the torque estimation relative to measured torque 相似文献
16.
Tian-Hua Liu 《Industrial Electronics, IEEE Transactions on》1995,42(1):17-24
This paper presents a new method to achieve a maximum torque for a single-phase induction motor. An AC adjustable capacitor using an electronic switch in parallel with a capacitor is proposed. The capacitor is short-circuited in a different period by an electronic switch during each cycle to vary the effective value of the AC capacitor. Two new optimization algorithms, which obtain a maximum starting torque by adjusting the effective capacitor, are proposed. No starting capacitor or centrifugal switch is used here. A theoretical analysis, and simulated and experimental results are presented in this paper 相似文献
17.
A mathematical analysis is presented that provides a theoretical explanation for the “let-go” neuromuscular stimulation phenomenon. This analysis includes consideration of electrophysiological, bioelectrical, and anthropometric factors that are involved in accidental electrical stimulation of forearm musculature during “let-go” 相似文献
18.
The add-on method utilizes previously acquired solutions for sub-problems, comprising portions of a scatterer, as a part of the analysis. The process of adding the remainder of the solution is a relatively efficient one, assuming that the initial stage of the sub-problem has been performed. The “add on” method is based on two basic principles: A. Superposition is used to break up the unknown current into two components, the first one being a readily computable solution to a simple short circuited problem, and the second one is excited by a current source over the aperture area, and is the only one requiring computation. B. A gradual algorithm is used for the computation of the second current component for many sub-problems. Principle A leads to a purely algebraic algorithm of principle B, with no integral operators. In this work, this formulation is extended to the cylindrical case. In this ease, the aperture region is a portion of a circle complementing the circular conducting shell, thus it shrinks as the conductor increases in size and no truncation is needed. The short circuit current for the closed circular cylinder is computed rapidly using the FFT. The cylindrical problem is solved for large cylinders in three ways: (1) a direct Moment Method solution, (2) a direct spatial decomposition solution based on the MoM matrix and invoking the matrix partitioning technique, and (3) the cylindrical add-on scheme. All solutions are identical, however, the computational advantage of the add-on technique is quite apparent, as seen from the analysis of the operation count as well as from numerical examples 相似文献
19.
Nagase H. Okuyama T. Takahashi J. Saitoh K. 《Industrial Electronics, IEEE Transactions on》1989,36(4):504-510
The authors examine a thyristor motor torque ripple suppression method that is simple in configuration. A simplified method of calculating motor torque ripple is introduced. This method enables calculation of velocity fluctuation due to torque ripple in the vicinity of the resonant frequency. Calculation results show that operation around the resonant frequency constitutes a problem. The current amplitude control method is effective for suppressing the torque ripple at the resonant frequency. This method detects the velocity fluctuation component and controls the current amplitude to eliminate that component. The velocity fluctuation component is detectable by using a filter that has a differential element. In addition, it is shown that the characteristic of the control system can be calculated with the aid of a Bode diagram, and its effectiveness is confirmed through simulation. From simulation results, this suppression method is found to be effective in reducing the velocity fluctuation to a practical level 相似文献