针对高频电源开关控制问题，提出改进序贯相似度检测(SSDA)的波形匹配方法来预测一次电流过零点，以控制高频电源开关元件开通和关断来提高高频电源输出功率。通过对SSDA算法阈值设定方法的改进,提高了该算法的匹配速度。首先，对不同条件下的一次电流波形进行取点，考虑波形采集过程的噪声，依次采取低通滤波和算术平均滤波的方法对采样数据进行处理后建立波形库。利用改进SSDA波形匹配的方法，根据匹配相似度较高的库中波形来预测目标波形的过零点时间，从而控制电源开关。实验结果证明，所提方法具有可实施性，且有较快的匹配速度以及较高的匹配精度。

This paper proposes a method based on improved SSDA waveform matching to forecast the zero-crossing point of primary current and to increase the output power of high-frequency power supply by controlling the opening and shut-off of high frequency source control circuit. First considering the noise in waveform sampling process a waveform database was established through the sampling low-pass filtering and arithmetic median filtering of primary current under different conditions.Then by using the improved SSDA waveform matching and according to the waveform in the database the zero-crossing of the target waveform was predicted to control the power switch.The experimental result showed that the method proposed here is feasible with high matching speed and matching precision.