飞机发电机控制器在检测电压有效值时，经常因为频率波动导致有效值计算出现误差。介绍了定频采样算法、过零点算法和准同步采样算法3种有效值算法，在MATLAB软件中进行了对比仿真，选取了误差最小的准同步采样算法。针对准同步采样算法响应时间过长的问题进行了改进，采用半周期积分优化的方法，并适当减少迭代次数。仿真与试验的结果证明，频率在380~420 Hz之间波动时，与传统定频采样算法相比，优化后的准同步采样算法误差从2.63%减小至0.14%。与优化前的准同步采样算法相比，优化后的响应时间从7.42 ms减小至2.46 ms。

When the aircraft generator controller detects effective voltage value, calculation error is often caused by frequency fluctuation. Three kinds of effective value algorithms are introduced, which are constant frequency sampling algorithm, zero crossing algorithm and quasi-synchronous sampling algorithm. Simulation in MATLAB shows that among the three algorithms, the quasi-synchronous sampling algorithm leads to the minimum error. For the problem of the quasi-synchronous sampling algorithm response time is too long, the semi-periodic integral optimization method is adopted, and the number of iterations is appropriately reduced. The results of simulation and experiment show that when the frequency fluctuates between 380 Hz and 420 Hz, the error of the improved quasi-synchronous sampling algorithm is optimized from 2.63% to 0.14% compared with the traditional constant frequency sampling algorithm. The response time is reduced from 7.42 ms to 2.46 ms compared with the quasi-synchronous sampling algorithm without optimization.