一种改进的基于采样-保持策略磁轴承用电流三态调制开关功放

An Improved Current-Controlled Tristate Switching Power Amplifier for Magnetic Bearings Based on Sample-Hold Strategy

提出一种改进的基于采样-保持策略的电流三态调制开关功放。它保留了基本采样-保持开关功放控制简单、动态响应快、频带宽、受负载影响小等优点,同时降低了开关功放的电流纹波和损耗,提高了功放的效率。此外还可以在不影响系统其他性能的情况下,通过提高输入电压来进一步提高系统的动态特性。同时还阐述了该改进型开关功放的工作原理及电路实现,对改进前后的开关功放进行了仿真比较,并通过对两种开关功放原理样机的实验测试,验证了改进型开关功放的优越特性。

An improved current-controlled tristate switching power amplifier based on sample-hold strategy is proposed in this paper。It can be implemented by a fairly simple circuit with high frequency bandwidth and fast dynamic response in a wide load range. The drawback of significant harmonic distortion produced by the fixed switching instants can also be overcome. By boosting the DC-link voltage, the improved power amplifier can work with a better dynamic characteristic without affecting other performance. The operation principle of the power amplifier is analyzed and the realization is introduced. Simulation comparisons are made to the two different power amplifiers. Two sets of prototype power amplifier are built to verify the performance of the improved power amplifier; the experimental results are also included in this paper.