500kW／380V国产大功率变频器在钻机上的应用

针对国外变频器价格昂贵、调试周期和维修周期长等特点，我公司自主研发了可替代进口机的高性能钻机国产专用变频器。该变频器能够从零开始调速。当钻井卡钻时，能及时断开电动机，在低速提升时，能最大限度地发挥电动机的动力特性，提供220％的转矩输出。变频器具有易安装、调试、维护，性能稳定。应用中据实测数据显示，采用变频改造后，打1口井可节省柴油15t。     

台达现场总线产品在中央空调系统的应用

本文通过案例详尽论述台达DeviceNet现场总线产品在中央空调系统的工程设计技术，展示出台达DeviceNet现场总线产品的系统集成优势。     

以国标GB1.7为指导编制“变流器包装”企业标准

介绍了某企业在变流器包装的设计和制定其企业标准的过程中执行ＧＢ１．７（标准工作导则）的情况，论述了在充分考虑产品特点和流通环境条件下，企标增补的内容，这些内容是对变流器包装有关标准的深化和创新。新企标不仅注重标准深度，而且考虑标准广度方面的拓展，代表了当前较好的生产水平，可作为生产过程中控制质量，评价和检验质量的依据。     

智能型逆变式恒电位仪

介绍了一种以ＩＧＢＴ为逆变器件的智能型逆变式恒电位仪的结构和工作原理。提出了由电位和电流双环控制、脉宽调制与脉频调制相结合的控制方法。还介绍了以单片机为核心组成的智能测控单元的结构和原理。试验表明，所研制的新型恒电位仪具有效率高、体积小、重量轻、功能全、安装使用方便等优点。     

The principle and fundamental characteristics of brushless three-phase synchronous induction motor with two stators

Brushless three-phase synchronous motor involving a rotating ac exciter on the same shaft as the motor and with the windings linked through a shaft-mounted rectifier is widely used as medium and large capacity machines. However, the motor needs to fit with damping windings for self-starting outside of the field winding in the rotor and needs to equip discharge resistance with complex electronic device to dispose of electromagnetic force induced in the field winding at starting. Therefore, the rotor structure is very complex, and there are disadvantages, especially for the robust and highly reliable motor that is desired. To solve the problem found in traditional motors, the authors proposed a brushless three-phase synchronous induction motor with two stators and one wound rotor. This problem is solved because the proposed motor is of two-stators structure: the rotor winding operates as a secondary winding of induction motor at starting and as the field winding at synchronous operation. The motor can self-start as a wound-rotor induction motor without external secondary resistance. Therefore, discharge resistance is not necessary; the starting equipment is very simple and the rotor structure is robust. It is possible to start with high torque. In this paper, the basic constitution of the proposed motor and the principles of operation are described in detail. The experimental results at starting and pulling into synchronism are shown for confirming the principles of operation and the experimental and numerical results of the starting characteristics. The load ones and the generating ones are shown and then the practical use of the proposed motor is confirmed.     

变频器的常见故障分析

本文阐述了变频器的常见故障，并针对常见故障提出了解决措施。     

浅谈变频器供电条件下电动机的温升与对策

随着变频调速技术的蓬勃发展，变频器供电电机的温升问题已引起人们的广泛关注。本文首先讨论了电动机的温升限度；然后结合感应电机温升实验的相关数据分析了变频器供电对电动机温升的影响及其原因；最后从降低发热量和提高散热能力两方面提出缓解电机温升的措施，并指出了实际应用中应注意的问题。     

变频器的选型及配置要点

本文针对应用广泛的通用变频器，提出了在变频器选型和外围配置中需要注意的一些问题。     

高输入功率因数的三相无源AC-DC变换器

对于采用三相不控整流桥作为前级的变换器，自然条件下其输入电流波形系数不高，使得输入功率因数委低，降低了电源的利用率。为此需要采用功率因数提高技术，其中无源PFC是一类重要的功率因数校正技术，在某些场合非常具有应用价值。本文介绍了几种三相无源AC-DC变换器的高功率因数方案，如采用LC滤波器、移相电抗器，谐振电抗器，移相变压器，相间变压器，相间电抗器等，在进行简单的工作原理描述后，给出了部分方案的MATLAB/SIMULINK仿真结果。     

电解防污用开关恒流源初探

对新研制的两种电解防污开关恒流源所采用的不同逆变器、开关功率管、直流工作电源及取样方式的工作状态、工作特性进行了分析比较。在研制过程中，重点解决了恒流电源工作的安全可靠性、稳定性、抗干扰能力及输出范围宽等问题。