磁轴承开关功放中电流三态调制技术的研究

针对传统磁轴承开关功放电流两态调制技术中存在的电流纹波大、动态特性受限等缺点，提出了电流三态调制技术。文中首先分析了电流纹波对磁轴承系统的影响，接着分析了电流两态调制技术本身的固有不足及电流三态调制技术在磁轴承开关功放应用中的优势。在对电流三态调制的基本理论进行一般性分析的基础上，提出了几种典型的电流三态调制开关功放，并做了较为细致的论述。最后通过一种具体的开关功放分别在两态调制和三态调制情况下进行仿真和实验比较，验证了电流三态调制技术的优越性，并给出了实验结果和波形。

RESEARCH ON CURRENT MODE TRI-STATE MODULATION TECHNOLOGY IN SWITCHING POWER AMPLIFIER FOR MAGNETIC BEARINGS

The standard bi-state switching power amplifier has its intrinsic deficiencies, such as significant harmonic distortion and restriction of the dynamic characteristic, which have serious negative effects on the magnetic bearing system. To overcome these drawbacks, the application of current mode tri-state modulation technology to the switching power amplifier for magnetic bearings is proposed, as well as its special advantages. On the basis of the general analysis of the cardinal principle of the current mode tri-state modulation technology, several typical practical power amplifiers using tri-state modulation technology are discussed in more detail. At last, the comparison of a concrete switching power amplifier working in different modulation technology by using computer simulation and experimental method shows the superiority of the current model tri-state modulation technology. The experimental results are also included in this paper.