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This paper introduce the technology of electromotor control and protective electrical appliance intelligent, using the artificial fish swarm algorithm (AFSA) which is based on genetic algorithm to optimize the calculate of the intelligent ac contactor. According to the result of optimization design, we have made a showpiece, after the test and experimentation of the prototype; finally we got results...
In this paper is presented the structure and working principle of the cascaded H-bridge multilevel converter with PWM rectifier and phase-shift transformer. Using the leak inductance as the filter reactor of the PWM rectifier can reducing the volume and cost of the converter; the phase-shift secondary side of the transformer can eliminate the current harmonics caused by the single power unit, restraining...
This paper describes a fuzzy control system and simulation for ultrasonic motors. Although ultrasonic motor has much merit, such as small size, light weight, high precision, fast control dynamics and large driving force when low speed, etc. However, the nonlinear dynamic characteristic and the accurate mathematical model is difficult to obtain. So the traditional control method is almost no effect...
We used to crank connecting shaft neck in the center of the neck as the origin of work piece coordinate system. Through the offset of the work piece coordinate, we made use of the method of the coordinate value in keeping with the real coordinate diameter or the relative location value of the work piece center. We designed a kind of crankshaft NC dresser which consists of the Siemens servo semi-closed...
This article presents speed controlling for single phase induction motor. Principally, 9-level, diode-clamp inverter used to control voltages per frequency is widely used because of its high efficiency to control the motor. In this article, ARM7 model ADU7024 is used as microcontroller to generate eight pulse signals and send to the output voltage amplifier by co-connecting to the modulation module...
In this paper, we present a variable speed wind induction generator associated to a flywheel energy storage system. Direct torque control strategy for an induction generator used in the flywheel energy storage system, is applied. Both rotor flux and DC bus voltage are regulated by the applied of the standard switching table for an operation in the 4 quadrants. This system is used for improving the...
The power demand is more than the generation and it is not economical & reliable to increase the generation by conventional sources. Day by day the use of non-conventional sources has been increased due to their economy and pollution free characteristics. This paper deals with the synchronization and stability of non-conventional source like Pico and micro hydro plant with thermal based synchronous...
In this paper, various dynamic slip control topologies are proposed for the control of grid connected opti-slip induction generator (OSIG). An elegant technique based on rotor voltage measurement has also been presented for mitigating output power fluctuations from OSIG, due to sudden wind gusts, tower shadow effect, etc. The control of OSIG is achieved using the basic principle of chopper control...
This paper proposes a new speed sensorless direct torque and flux controlled interior permanent magnet synchronous motor (IPMSM) drive. Closed-loop control of both the torque and stator flux linkage are achieved by using two proportional-integral (PI) controllers. The reference voltage vectors are generated by a space vector modulation (SVM) unit. The drive uses an adaptive sliding mode observer for...
Thyristor based, phase angle controlled, speed regulators are widely used for energy efficient control of single-phase induction motors. This leads to power saving but adversely affects the life of insulation in the motors due to non-sinusoidal voltage and current waveforms. The accelerated insulation ageing is due to increased voltage peaks, voltage transients, sharp dV/dt and increased thermal stress...
In this paper, two control strategies for three-phase series-parallel uninterruptible power supplies are compared. A series-parallel UPS consists of a parallel and a series converter. In this topology, most power required by load is supplied directly from AC line during standby mode. Therefore the overall efficiency is higher than that of a conventional UPS. Traditionally, the control strategy of...
The control for a diode-clamped three-level half bridge converter is researched in this paper. The reasons for the input current distortion around the zero-crossing point of the input voltage based on the voltage zero-crossing detection control are analyzed in detail, and a hybrid control which combines the reference voltage feed-forward control with the feedback control is proposed to prevent the...
A high performance modular three-phase utility-interactive converter is designed and implemented in this paper. This converter has three operation modes: grid-connection inverter mode, stand-alone inverter mode and rectifier mode. Control principles and modes of every mode are analyzed in detail and the modular design method is adopted. A simple but valid control strategy is proposed. Finally a 10...
This paper describes the optimal control of variable-speed permanent magnet synchronous generators system. In order to maximize generated power, permanent synchronous generator is controlled by a maximum power point tracking (MPPT) control and maximum efficiency control. A sensor-less scheme is proposed for MPPT. Experimental results have been carried out to verify the benefits of the proposed system.
A novel V/F induction motor control system based on stator voltage oriented method is presented. This scheme includes dead time compensation, stator voltage compensation and anti-oscillation regulation, which can greatly improve the V/F systempsilas performance especially low frequency load capability and fast response capability. Different from conventional V/F methods, all the compensation and regulation...
Direct torque control based on space vector modulation (SVM-DTC) preserve DTC transient merits, furthermore, produce better quality steady-state performance in a wide speed range. In this paper, a torque fuzzy logic controller was designed to substitute the original torque PI controller, and a fuzzy SVM-DTC system based on the torque fuzzy controller was given. A new integration algorithm for estimating...
The current source back-to-back converters have been largely neglected because of the slow transient response and low power factor, which is mainly resulted from a fixed PWM pattern and a poor control method. However, current source converters have intrinsic advantages such as the high reliability and the inherent current limiting capability. Due to these advantages, more and more people have been...
Direct torque control of brushless DC motor (BLDC) is complex for turn-off phase. And the direct torque control of brushless DC motor based on hyper space vector solved the problem, however, the torque ripple was obvious. A modified method is presented in this paper in order to reduce the torque ripple based on hyper space vector. For the turn-off phase only affects the stator flux linkage but not...
Five-level inverter has been applied to industry and railway traction to solve the difficulty in applying low-voltage or medium-voltage switch devices to high-voltage system. The basic principle of diode-clamped five-level inverter is analysed in this paper. Based on the analysis of diode-clamped three-level inverter, single pulse control method, pulse width modulation(PWM) control methods and a novel...
A novel sensorless control for switched reluctance motor (SRM) driven by the three-phase full-bridge inverter is proposed. The most commonly used drive for SRM is the asymmetric half-bridge inverter but its main disadvantage is the cost due to the number of switches and diodes required to realized the drive, in comparison with the much cheaper and more widely available three-phase full-bridge inverter...
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