高压变频器在煤矿皮带机上的应用

本文主要介绍了北京利德华福电气技术有限公司研发的高压变频器在煤矿皮带机上的实际应用情况。该项目采用1台高压变频器拖动2台电机同时运行的直接"一拖多"方案。现场实际应用表明,此方案下,各电机实时转速相等,电流一致性较好,满足皮带运行工况要求。     

级联型变频器在高压大功率电机软启动中的应用

为了解决高压大功率电机软启动技术实现难的问题,文中介绍一种基于单元级联型高压变频器的电机软起动应用方法,利用高压大功率变频器的特点,用其作为高压大功率电机的软启动器,使得高压大功率电机能够平稳、无冲击、大转矩启动。     

集装箱式高压变频器系统在磨机上的应用

为实现磨机的平稳启动及调速,在电力驱动系统中增加了高压变频器驱动。并通过一台变频器拖动两台磨机的方案,实现了多机软启动。为了减少现场工作量,配置电气设备集装箱,将变频器及高压电控系统集成一体化设计,作为一个整体提供给客户,大大减少现场施工任务,设备对现场环境适应性更强。     

合康变频同步控制在煤矿皮带机上的应用

本文主要介绍合康变频大功率变频器采用主从同步控制在煤矿皮带机上的应用。主从同步控制能使拖动同一设备的多台电机速度同步,输出功率均衡。控制性能优良,运行稳定、可靠,节能效果明显。     

DWR-1型电机软启动器的自动旁路运行

<正> DWR-1型电机软启动器采用全数字电路及模块式结构,具有结构简单、维护容易、使用可靠、价格低廉、自动保护功能齐全、良好的软启动能力、能大幅度降低配电容量、提高生产效率等特点。特别是该产品在启动结束后,投入正常运行时,采用了自动切换接触器旁路运行,自动脱离、关闭软启动装置,使运行电路更简单、更直观,故障率更少、抗干扰能力更强,软启动器使用寿命更长,使电路更加稳定可靠。又由于在自动旁路切换时接触器无电弧现象,所以更延长了接触器的使用寿命。而且还可实现多路组合式软启动控制,每路都可单独控制,互不影响,实现真正的一台拖动多台的软启动控制功能。该产品能适用于各种交流电动机的启动控制使用,是电机启动控制设备领域中的更新换代新产品,产品有15～200kW各种规格。     

多电机拖动皮带输送机恒压频比控制变频器

在变频器驱动多机拖动皮带机系统中,一个重要的问题是如何解决系统中各个电动机的功率输出平衡。本文介绍了一种基于恒压频比控制型的多机拖动皮带机变频器。变频器采用主从控制模式,通过对各自有功电流做闭环控制来实现对其输出频率的调整。变频器的输出电压按照恒压频比控制方式,保证了电机气隙磁通的恒定,最终能够达到各个电动机输出功率一致的目的。通过现场的成功应用,证明了恒压频比控制型多机拖动皮带机变频器的有效陛和实用性。     

彩色印刷机中多电机远程同步传动控制软件的开发

根据彩色印刷机中多电机远程同步传动控制的要求，采用组态软件开发上位机控制软件，实现远程控制4台交流电机协调同步运行，其驱动为4台西门子变频器，该系统实现了与局域网的联接，可在网络上进行历史数据查询和历史报表打印。     

皮带运输机专用高压变频器的设计

本文针对由3台高压异步电机拖动的皮带运输机，若采用常规高压变频器实现调速控制时，将出现对转差能量处理、多电机环流、3电机同轴同步控制等技术难度问题。设计出了一种JCC型皮带运输机专用高压变频器，成功地应用在大同马脊梁煤矿外运皮带机。共用了3台6kV／500kW高压电机的变频拖动。拓展了IGBT高压变频器在多电机的同轴、同步控制应用的新领域。     

“一变多控”变频控制技术在海上油田的应用

针对WZ11-1油田三台注水泵采用自耦变压器进行降压启动,设备故障率高,而且启动的同时对注水泵出口设备影响和电网冲击较大的问题,利用油田在原油外输泵控制系统中已经配置的一台变频器,采用"一变多控"中压变频控制技术,对油田三台注水泵和两台原油外输泵的控制系统进行改造,实现一台变频器控制三台注水泵和两台原油外输泵的变频启动工频运行,最后一台泵可变频控制运行的控制模式。应用结果表明,"一变多控"中压变频控制技术科学合理,为油田实现平稳生产和降本增效奠定基础。     

艾默生工控产品在皮带机启动控制中的应用

文章介绍了艾默生公司变频器EV3000在送料皮带机上的应用,通过E020系列PLO及模拟量处理,实现两台EV3000变频器之间的主从控制,实现皮带的平滑启动和主从运行。     

Quick response and low-distortion current control for multipleinverter-fed induction motor drives

This paper describes a PWM control method to balance two unit inverter currents and to reduce the distortion of motor currents in a multiple GTO inverter for large capacity AC variable-speed drive systems. For an 11 kW induction motor driven by a 15 kVA multiple inverter, the imbalance current can be reduced to less than 5% of the rated motor current, and the motor current waveform can be made very close to sinusoidal. The GTO switching frequency in the multiple inverter can be lowered to one-quarter of that in the single inverter. In a 2750 kVA GTO inverter drive system which was developed based on the 15 kVA multiple inverter, excellent performance is obtained including unity power factor operation at an AC power source, smooth 4-quadrant operation, and quick speed response of 85 rad/s. The quick response is realized by field-oriented control with decoupling control between torque and exciting currents, and direct control of three-phase AC currents. In the future, the multiple GTO inverter is expected to be applied to rolling mill drives instead of cycloconverters     

高压变频器在西北腾达铁合金的应用

本文介绍了高压大功率变频器在西北腾达铁合金新上冶炼电炉工程项目中的应用,说明了变频器在软启动、故障软切换、运行可靠性、节髓等方面的应用优势,展示了变频器的应用前景。     

A modified current source inverter (MCSI) for a multiple inductionmotor drive system

A modified current-source inverter (MCSI) that can drive multiple motors is presented. The MCSI combines the features of the current-source inverter and the voltage-source inverter. It also overcomes major shortcomings of the current-source inverter. The commutation process of the inverter is described. Design considerations are briefly introduced. Some experimental results are given for five 1-hp induction motors running in parallel from a single MCSI     

Combined low-cost, high-efficient inverter, peak power tracker andregulator for PV applications

A novel compound power converter that serves as a DC-to-AC inverter, maximum power point tracker (MPPT), and battery charger for stand-alone photovoltaic (PV) power systems is introduced. A theoretical analysis of the proposed converter is performed, and the results are compared with experimental results obtained from a 1.5 kW prototype. The overall cost of PV systems can thus be reduced by using load management control and efficiency-optimization techniques. Power flow through the converter is controlled by means of a combination of duty cycle and output frequency control. With load management, large domestic loads, such as single phase induction motors for water pumping, hold-over refrigerators, and freezers, can be driven by day at a much higher energy efficiency. This is due to the high efficiency of the inverter with high insolation, and because the inverter uses the energy directly from the solar array. The battery loss component is thus reduced     

Light‐Driven Liquid Crystalline Networks and Soft Actuators with Degree‐of‐Freedom‐Controlled Molecular Motors

Design and fabrication of photomechanical soft actuators has attracted intense scientific interest because of their potential in the manufacture of untethered intelligent soft robots and advanced functional devices. Trifunctional and monofunctional polymerizable molecular motors are judiciously designed and synthesized. Novel light‐driven liquid crystalline networks (LCN) are prepared by crosslinking overcrowded‐alkene‐based molecular motors with different degrees of freedom into the anisotropic LCN. The photoisomerization and thermal helix inversion of light‐driven molecular motors are reversible when only the upper part of the molecular motor is linked to the network, endowing the LCN film with remarkable photoactive performance. However, photochemical geometric change of the light‐driven molecular motor does not work after crosslinking both the upper and lower part of the motor by polymer chains. Interestingly, it is found that the fastened motor can transfer the light energy into localized heat instead of performing photoisomerization. The light‐driven molecular‐motor‐based LCN soft actuators are demonstrated to function as a grasping hand, where the continuous motions of grasping, moving, lifting, and releasing an object are successfully achieved. This work may provide inspiration to the preparation of next‐generation photoactive advanced functional materials toward their wide applications in the areas of photonics, optoelectronics, soft robotics, and beyond.     

感应电动机智能软启动器研究

为了解决三相异步电动机起动电流较大的问题,采用了一种软起动模糊自适应控制器。据其起动特性,将电流误差和误差的变化率作为输入量,晶闸管的控制角作为输出量,设计出一种自调整比例因子的模糊自适应控制算法。随后做了Matlab环境下的仿真实验,并且与常规的PID控制方法和常规模糊控制方法进行比较,得到了模糊自适应控制算法具有优越性的结论。     

Extending the constant power speed range of the brushless DC motor through dual-mode inverter control

An inverter topology and control scheme has been developed and tested to demonstrate that it can drive low-inductance, surface mounted permanent magnet motors over the wide constant power speed range (CPSR) required in electric vehicle applications. This new controller, called the dual-mode inverter controller (DMIC) , can drive both the Permanent Magnet Synchronous Machine with sinusoidal back emf, and the brushless dc machine (BDCM) with trapezoidal emf as a motor or generator. Here we concentrate on the application of the DMIC to the operation of the BDCM in the motoring mode. Simulation results, supported by closed form analytical expressions, show that the CPSR of the DMIC driven BDCM is infinite when all of the motor and inverter loss mechanisms are neglected. The expressions further show that the ratio of high-to-low motor inductances accommodated by the DMIC is 11 making the DMIC compatible with both low- and high-inductance BDCMs. Classical hysteresis-band motor current control used below base speed is integrated with DMICs phase advance above base speed. The power performance of the DMIC is then simulated across the entire speed range. Laboratory testing of a low-inductance, 7.5-hp BDCM driven by the DMIC demonstrated a CPSR above 6:1. Current peak and rms values remained controlled below rated values at all speeds. A computer simulation accurately reproduced the results of lab testing showing that the limiting CPSR of the test motor is 8:1.     

基于FPGA及DDS技术的USM测试电源的设计

超声波电机的运转需要一个两相相差90°（或可调）的高频交流信号源。本方案采用DDS技术的设计思路,用VHDL硬件描述语言对FPGA器件编程产生了两相四路高频信号。该信号经过驱动隔离电路施加于H桥逆变器中,在电感的平滑作用下,生成了满足USM测试要求的可调频、调相、调幅的两相高频交流信号源,成功地对USM45电机进行了驱动测试。该电路可用于研究超声波电机的运行状态的研究及获取其最佳工作点参数。     

基于IR2155 的高压钠灯电子镇流器设计

本文针对高压钠灯电子镇流器设计中，开关损耗大、驱动复杂、启动速度慢等问题，提出一种高性能高压钠灯用电子镇流器电路。该电路成功的应用了L6560校正芯片和IR2155专用半桥驱动芯片，即简化了传统的驱动电路，又实现了变频调节，提高了启动速度，保证了灯功率的稳定。通过频率和辅助元件的设置，半桥逆变电路可工作在软开关状态。同时设计出可靠的、能产生3．5kV电压的启动电路，保证灯在热灯熄灭时，切断触发脉冲，而后自动恢复启动状态。实验结果表明该镇流器性能优良，功率因数大于0．99，启动时间小于2.4min。