一种基于分段线性化的高效率线性功率放大器

A High Efficiency Linear Power Amplifier Based on Piecewise Linearization

在互感器校验用电源中,存在电工电源调节精度不高、开关型逆变电源容易产生谐波干扰、线性电源效率较低等难题,为此,本文提出一种基于分段线性化高效率线性功率放大器方案,该方案可有效改善电源输出波形质量,提高电源的整体效率使得热损耗大幅降低,实现输出电压的精细调节。该电路拓扑具有多电平分级的结构特点,分段对正弦信号进行线性化功率放大,大幅降低功率管在工作时的管压降,从而在使系统效率大幅度提高的同时,保留了传统线性功率放大器输出波形质量高、电磁干扰低等优点。为验证方案的正确性,搭建了一个8电平的功率放大器,最高效率达到94%,显示出良好的性能。

Among different types of power supplies for transformer calibration,the common electric power supply does not have precise adjustment,the switching type inverter power supply is easy to produce harmonic interference,and the efficiency of linear power supply is relatively low.To solve these problems,this paper develops a high efficiency linear power amplifier scheme based on piecewise linearization,which can effectively improve the output waveform quality of power supply,improve the overall efficiency of power supply,greatly reduce the heat loss,and realize the fine regulation of output voltage.The proposed circuit topology has the characteristics of multi-level hierarchical structure.The sinusoidal signal is linearized by segments,which greatly reduces the voltage sag of the power transistor in operation.Therefore,the system efficiency is greatly improved,while the advantages of the traditional linear power amplifier,such as high output waveform quality and low electromagnetic interference,are retained.An eight-level power amplifier is built to verify the correctness of the scheme,and it turns out that the highest efficiency reaches 94%,showing good performance.