Research on a new type of electromagnetic transmitter based on PWM technology

An electromagnetic transmitter transmits electromagnetic waves with variable frequencies to the ground to obtain underground structure information and the distribution of mineral resources. In order to improve the power factor and reduce the volume and weight of the transmitter, a novel transmitter topology with pulse width modulation (PWM) rectifier is designed. Similar with the flux-oriented control in the motor speed regulation system, this paper provides flux-oriented control for a permanent magnet synchronous generator PWM rectifier. The mathematical model of the generator rectifier is established under the rotating coordinate system. Then, a novel decoupling control strategy without the exact value of the generator stator inductance is proposed to regulate the active current and the reactive current, and an outer voltage linear control strategy with the control amount of the square of the voltage is proposed to regulate the output voltage. Simulation and experimental results demonstrate the effectiveness of the system.