基于改进粒子群优化算法的可控发射电流频率SHEPWM控制方法

针对传统方法控制的发射电流频率间隔固定、 频域不完全可控的问题, 为提高频率域电磁测深效率, 提出一种基于改进粒子群优化算法的可控发射电流频率的选择性谐波消除脉宽调制(SHEPWM)控制方法. 先根据勘探目标计算出期望的频谱, 再根据发射电流的时频域特性建立半周期镜像对称SHEPWM非线性方程组, 最后采用改进粒子群优化算法对非线性方程组求解, 得到对应的开关时刻序列, 由开关时刻序列控制发射系统逆变器, 即可输出探测所需的发射电流.  当勘探特定深度目标时, 发射系统可输出最优的发射电流, 进而提高纵向分辨率.

SHEPWM Control Method of Controllable Emission Current Frequency Based on Improved Particle Swarm Optimization Algorithm

Aiming at the problem that the frequency interval of emission current controlled by traditional method was fixed and the frequency domain was not completely controllable, in order to improve the efficiency of frequency domain electromagnetic sounding, we proposed a selective harmonic eliminated pulse width modulation (SHEPWM) control method based on improved particle swarm optimization algorithm. Firstly, the expected spectrum was cal culated according to the exploration target. Secondly, the half-cycle symmetric SHEPWM nonlinear equations were established according to the time-frequency domain characteristics of the emission current. Finally, the improved particle swarm optimization algorithm was used to solve the nonlinear equations, and the corresponding switching time sequence was obtained. By controlling the inverter of the emission system by the switching time sequence, the emission current required for detection could be output. When the depth target was explored, the launch system could output the optimal launch current, and then improve the vertical resolution.