大功率海洋电磁发射机DC-DC可控源电路特性分析

Characteristics Analysis of High Power Marine Electromagnetic Transmitter DC-DC Controlled Source Circuit

海洋电磁发射机通过向海底发射大功率的电磁波,来获取海底结构和矿产资源的分布规律,但目前发射机存在体积大、发射功率小等问题,直接影响勘探深度。提出采用PWM变换器组成发射机DC-DC可控源电路,然而常规的零电压开关全桥(ZVS-FB)PWM变换器存在高环流能量、占空比丢失以及滞后桥臂的ZVS范围受限等问题,为此介绍一种利用零电压零电流开关全桥(ZVZCS-FB)PWM变换器组成可控源电路。采用非对称移相控制,分析电路工作过程及特性,主要包括最大控制占空比、一次电流复位和隔直电容、占空比丢失、开关损耗以及环流能量等。仿真和实验结果表明该DC-DC可控源电路实现了超前桥臂的ZCS开通和ZVS关断以及滞后桥臂的ZCS开通和关断,提高了电路效率和功率密度。

Marine electromagnetic transmitter transmits large power electromagnetic wave to the seabed for obtaining the submarine structure and mineral resources.However,the current transmitter has the problems of large volume and low transmission power.In this paper,PWM converter is used to construct the DC-DC controllable source circuit.Since the conventional zero voltage switching full bridge(ZVS-FB)PWM converter has many limitations,such as high loop energy,loss of duty cycle and limited ZVS range of lagging bridge arm,a zero voltage zero current switching full bridge(ZVZCS-FB)controlled source circuit is proposed using asymmetric phase-shifted control.The operating process and circuit characteristics of ZVZCS-FB-PWM DC-DC controlled source circuit are analyzed,including the maximum control duty ratio,reset primary current and capacitance,the loss of the duty ratio,the switching loss and energy circulation etc.Simulation and experimental results show that the DC-DC controlled source circuit realizes the leading-leg switches to be operated with ZCS turn-on and ZVS turn-off,the lagging-leg switches with ZCS turn-on and turn off.The circuit efficiency and power density are accordingly improved.