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排序方式: 共有41条查询结果,搜索用时 15 毫秒
1.
A new single-stage power factor corrected ac–dc converter for universal line applications is proposed in this paper. This converter has a buck topology as a power factor corrector. The dc bus voltage of the proposed converter is always lower than the peak input voltage at any load condition. Therefore, the problem of high dc bus voltage under the light load condition for the single-stage converter is solved, especially in the case of universal line applications. The design equations are presented for the proposed converter and a design example for a 5V 12A application is presented. The theoretical analysis and experimental results show that the dc bus voltage can be limited within 260V and the line input current harmonics can meet IEC 61000-3-2 Class D requirements at any load conditions for the line input voltages from 90 to 260Vac.  相似文献   
2.
A DSP-based nonlinear speed control of a permanent magnet synchronous motor (PMSM), which is robust to unknown parameter variations and speed measurement error, is presented. The model reference adaptive system (MRAS)based adaptation mechanisms for the estimation of slowly varying parameters are derived using the MIT rule. For the disturbances or quickly varying parameters, a quasi-linearized and decoupled model including the influence of parameter variations and speed measurement error on the nonlinear speed control of a PMSM is derived. Based on this model, a boundary layer integral sliding mode controller to improve the robustness and performance of a PMSM drive is designed and compared with the conventional controller. To show the validity of the proposed control scheme, simulations and experimental works are carried out and compared with the conventional control scheme.  相似文献   
3.
A new discontinuous modulation method based on space-vector control is proposed and analyzed. The proposed technique employs a pulse-dropping method and is designed in the time domain. It features a very wide modulation range while maintaining the required waveform qualities and switching numbers in the overmodulation region. Since the modulation method and modulation index equation are simple, the proposed technique can be easily implemented by software and is applicable to the overmodulation region in ac motor drives. The performance indexes are discussed and experiments have been performed.  相似文献   
4.
A new sustainer circuit with multilevel voltage wave-shaping characteristics for an AC plasma display panel (AC-PDP) drive is proposed. The proposed circuit features half the device voltage stresses and significantly reduced power losses compared with those of the conventional ones. This circuit, realizable without much increased cost of the semiconductor devices, gives a significant improvement in the power efficiency, essential for the design of a drive circuit for the AC-PDP. A comparative analysis and experimental results are presented to show the validity of the proposed sustainer circuit.  相似文献   
5.
On-line dead-time compensation method using disturbance observer   总被引:7,自引:0,他引:7  
A new on-line dead-time compensation method for a permanent magnet (PM) synchronous motor drive is proposed. Using a simple disturbance observer without any additional circuit and off-line experimental measurement, disturbance voltages in the rotor reference dq frame caused by the dead time and nonideal switching characteristics of power devices are estimated in an on-line manner and fed to voltage references in order to compensate the dead-time effects. The proposed method is applied to a PM synchronous motor drive system and implemented by using software of a digital signal processor (DSP) TMS320C31. Simulations and experiments are carried out for this system and the results well demonstrate the effectiveness of the proposed method.  相似文献   
6.
A new phase-shifted parallel-input/series-output dual converter is proposed. It features a low-output voltage ripple, a low rms current in the output capacitor, and a greatly reduced constant switch turn-off stress, whereby the efficiency is significantly improved. This converter is considered to be well suited to high-power step-up applications  相似文献   
7.
A new instantaneous torque-control strategy is presented for high-performance control of a permanent magnet (PM) synchronous motor. In order to deal with the torque pulsating problem of a PM synchronous motor in a low-speed region, new torque estimation and control techniques are proposed. The linkage flux of a PM synchronous motor is estimated using a model reference adaptive system technique, and the developed torque is instantaneously controlled by the proposed torque controller combining a variable structure control (VSC) with a space-vector pulse-width modulation (PWM). The proposed control provides the advantage of reducing the torque pulsation caused by the nonsinusoidal flux distribution. This control strategy is applied to the high-torque PM synchronous motor drive system for direct-drive applications and implemented by using a software of the digital signal processor (DSP) TMS320C30. The simulations and experiments are carried out for this system, and the results demonstrate the effectiveness of the proposed control  相似文献   
8.
The continuous, accurate, and robust sliding mode tracking controller based on a disturbance observer for a brushless direct drive servo motor (BLDDSM) is presented. Although the conventional sliding mode control (SMC) or variable structure control (VSC) can give the desired tracking performance, there exists an inevitable chattering problem in control which is undesirable for a direct drive system. With the proposed algorithm, not only are the chattering problems removed, but also the prescribed tracking performance can be obtained by using the efficient compensation of the disturbance observer. The design of the sliding mode tracking controller for the prescribed, accurate, and robust tracking performance without the chattering problem is given based on the results of the detailed stability analysis. The usefulness of the proposed algorithm is demonstrated through the computer simulations for a BLDDSM under load variations  相似文献   
9.
A high-performance and low-cost single-switch current-fed energy recovery circuit (ERC) for an alternating current (ac) plasma display panel (PDF) is proposed. Since it is composed of only one power switch compared with the conventional circuit consisting of four power switches and two large energy recovery capacitors, it features a much simpler structure and lower cost. Furthermore, since all power switches can be switched under soft-switching operation, the proposed circuit has desirable merits such as an increased reliability, and low switching loss. Especially, there are no serious voltage notches across the PDP with the aid of gas discharge current compensation, which can greatly reduce the current stress of all inverter switches, and provide those switches with the turn on timing margin. To confirm the validity of the proposed circuit, its operation and performance were verified on a prototype for 7-in test PDP.  相似文献   
10.
A combined buck and boost push-pull quantum series resonant rectifier (PPQSRR) is newly proposed to achieve power factor correction without start-up inrush current. With the proposed control method and circuitry, a high power factor and wide range of output voltage without an inrush current can be obtained  相似文献   
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