SPWM三相变频调速电路的谐波分析

在理论分析和电路仿真实验数据的基础上，总结出SPWM三相变频器谐波的分布特点，为变频器输出滤波器设计提供了理论依据，并通过电路仿真实验予以验证。     

2800mm中板加热炉辊道的变频改造

详细阐述了2800mm中板加热炉装出料辊道控制系统由晶闸管交流电子开关柜改为变频器的具体设计方案和实现方法，重点是该改造满足生产要求的良好应用效果及PLC控制实现调速的应用特性。     

用于三相PWM并网逆变器的改进型幅相控制方法

In this paper, a vector regulating principle of the phase and amplitude control （ PAC ） method for three-phase grid-connected inverters is presented. To solve the problem of heavy inrush current and slow dynamic response when system starts up, the starting voltage prediction control and the current feed-forward control are proposed and used, which improve the dynamic performance of the system in the PAC. The experimental results carried out on a three-phase grid-connected inverter proved the validity of the proposed method.     

太阳能光伏发电系统的设计

从生态村公用楼道照明的实际需要出发,采用模块组合的方法研究和设计了一套太阳能光伏发电系统,为节能减排、公共照明免费供电作了有益的探索.该系统若遇长期阴雨天,能通过控制器自动切换至市电供电.     

Study on inverter fault-tolerant operation of PMSM DTC

This paper presents an investigation of inverter fault-tolerant operation for a permanent magnet synchronous motor （PMSM） direct torque control （DTC） system under various inverter faults. The performance of a faulty standard 6-switch inverter driven PMSM DTC system is analyzed. To avoid the loss or even disaster caused by the inverter faults, a topology-modified inverter with fault-tolerant capability is introduced, which is reconfigured as a 3-phase 4-switch inverter. The modeling of the 4-switch inverter is then analyzed and a novel DTC strategy with a unique nonlinear perpendicular flux observer and feedback compensation scheme is proposed for obtaining a continuous, disturbance-flee drive system. The simulation and experimental results demonstrate that the proposed inverter fault-tolerant PMSM DTC system is able to operate stably and continuously with acceptable static and pretty good dynamic performance.     

户用发电机逆变电源设计

本文介绍了一种户用发电机逆变电源系统。系统主电路采用交直交变换电路,整流电路采用晶闸管半控过零整流,逆变器采用单相桥式正弦脉宽调制(SPWM)方式,把中频发电机400HZ、300～400V三相交流电转变成220V、50HZ单相工频正弦交流电。     

Design and implementation of a position sensorless control method for brushless DC motors

Because brushless direct current (BLDC) motors have the advantages of a compact size, high power density, high efficiency, and long operating life time, they are widely used in many industrial products and electric traction systems. It is known that the BLDC motors have no brushes for commutation. They are commutated with electronically commutation. So, the rotor position information of the BLDC motors must be known to understand which winding will be energized according to the energizing sequence. In most of the existing BLDC motor drivers, rotor position information is detected by Hall effect sensors. This kind of mechanical position sensors will bring additional connections and costs, reliability decrease and noise increase. In order to improve the control performance and extend the range of speed regulation for BLDC motors, a position sensorless control method is proposed in this paper. In the proposed control method, rotor position information of the BLDC motors is detected from the back electromagnetic forces (back-EMFs) which are estimated by an unknown-input observer with line to line currents and line to line voltages. For the purpose of verifying the effectiveness of the proposed control method, a model is built and simulated on the Matlab/Simulink platform. The simulation results show that the speed regulation performance of BLDC motors is improved compared with using Hall effect sensors. At the same time, the reliability of the BLDC motors is improved and the costs of them are reduced because the position sensor is eliminated.     

500W逆变电源的设计

使用蓄电池储存太阳能,设计一高频变换电路提升为320V直流高压,经过SPWM逆变形成50Hz正弦交流电。对二次变换的缘由、逆变电路的构成、高频变压器的设计计算、SPWM芯片及驱动程序、H桥逆变电路的工作原理作了详细介绍。     

60kV开关型直流高压电源

为提高教学实验的水平,适应当前国内,外发展的趋势,本文主要介绍了采用大功率电力电子器件ＩＧＢＴ的电力电子技术,将交流电源从５０Ｈｚ交流变成直流,又变成高频（１０ｋＨｚ～２０ｋＨｚ）的交流,然后再用串级直流电路而得到高压电流,这样不仅使用方便,便于携带,而且安全可靠,大大提高了教学水平,推进了高电压技术的发展。     

电磁炉原理与常见故障分析

随着生活水平的提高,老百姓对安全卫生的炊事用具逐渐接受,电磁炉也进入了千家万户。所以电磁炉常见故障分析就显得很有必要。