Research on motor control method of high-speed continuous wave mud pulse generator

Continuous-wave mud pulse transmission technology utilizes pulse generator as a carrier to realize data transmission through pressure waves. The effectiveness of signal generation is closely tied to the pulser control method. In this paper, numerical simulation and experimental methods are used to study the pulse generator high-speed control method. The findings indicate that, under unchanged conditions, the rotor's swing amplitude or final angle gradually increases, leading to a progressive rise in the peak value of the pressure wave. Subsequently, the pressure wave gradually tends towards a "rectangular" shape, resulting in distortion and reaching the limit conditions of waveform rounding. Experimental validation has been conducted to affirm the realism of the simulation. Based on the experimental results, a criterion for determining harmonic amplitude ratios has been proposed. The harmonic amplitude ratios α and β are the primary and secondary criteria respectively, which are used to evaluate the quality of the pressure signal. Tests 3, 6, 12 and 17 were initially preferred for good signal quality. The evaluation of pressure signal quality requires comprehensive consideration of pressure, harmonic amplitude ratio and other factors. Specifically better signal quality: 180° swing amplitude, motor zero position 220° (Test 6; 6Hz); 150° swing amplitude, motor zero position 210° (Test 12; 12Hz). Consequently, these two control strategies should be prioritized in the design of high-speed continuous-wave mud pulsers.