【目的】自励磁同步电机(SESM)结构简单、成本低，通过基波电流和高频正弦电流共同励磁。但高频电流会引入高次谐波，导致定子与转子磁场相互作用，产生径向电磁力，引发电机振动和形变，进而生成令人不适的高频电磁噪声。【方法】针对高频正弦电流励磁引发的电磁噪声问题，本文提出一种高频方波注入励磁策略。该策略利用方波低载波比特性，将注入频率提升至人耳敏感频段(1~5 kHz)外，有效降低噪声影响。首先，通过功率谱密度分析高频正弦电流的噪声特性；其次，提出方波策略并分析其响应电流的频谱；最后，基于磁动势理论验证策略，并在自励磁电机平台上进行试验。【结果】试验结果表明:与传统励磁策略相比，本文所提高频方波励磁策略在保证相同励磁效果的前提下，能将人耳敏感频段内的功率谱密度降低51.86 dB/Hz，显著削弱噪声影响。【结论】本文所提高频方波励磁策略可有效降低人耳敏感频段内的电磁噪声，解决了传统励磁策略电磁噪声过大的问题，为SESM提供了可靠低噪声的控制方案。

[Objective] The self-excited synchronous motor (SESM) has a simple structure and low cost, utilizing both fundamental current and high-frequency sinusoidal current for excitation. However, the high-frequency current introduces higher-order harmonics, causing interaction between the stator and rotor magnetic fields. This generates radial electromagnetic forces, leading to motor vibration and deformation, and ultimately producing uncomfortable high-frequency electromagnetic noise. [Methods] To address the electromagnetic noise issue caused by high-frequency sinusoidal current excitation, a high-frequency square wave injection excitation strategy was proposed. The strategy utilized the low carrier ratio characteristic of square waves to elevate the injection frequency beyond the human auditory sensitive range (1~5 kHz), effectively reducing noise impact. Firstly, the noise characteristics of high-frequency sinusoidal current were analyzed through power spectral density. Next, the square wave strategy was proposed and its response current spectrum was examined. Finally, the strategy was verified based on magnetomotive force theory and tested on a self-excited motor platform. [Results] The experimental results showed that, compared with the traditional excitation strategy, the proposed high-frequency square wave excitation strategy could reduce the power spectral density in the human auditory sensitive range by 51.86 dB/Hz while ensuring the same excitation effect, significantly mitigating the noise impact. [Conclusion] The proposed high-frequency square wave excitation strategy effectively reduces electromagnetic noise in the human auditory sensitive range, addressing the issue of excessive noise in traditional excitation strategies and providing a reliable low-noise control solution for SESM.

国家自然科学基金(52307072);福建科技计划-STS院省合作项目(2023T3046,2023T3015)