TEM-Ⅱ型电磁法发射机换相过程的研究

Study on Phase Conversion Process and Releasing Imaginary Power of Loop in TEM-ⅡTransmitter

简要介绍了TEM -Ⅱ型瞬变电磁法发射机及其工作原理 ,引出了TEM -Ⅱ型瞬变电磁法发射机在感性负载下电压、电流存在瞬态变化过程 ,全桥电路在实现功率变换时存在换相过程及无功功率释放的问题。分析了负载电压、电流的瞬态变化规律 ,阐明了无功功率释放回路的意义和作用。结合TEM -Ⅱ型瞬变电磁法发射机阻感性负载情况下 3种工作方式 ,对由全控型器件IG BT构成的全桥电路的换相过程作了深入全面的讨论 ,并给出了 3种工作方式的实测输出电压、电流波形。绘出了方式一的换相过程中电流流向及方式二的换相过程中开关动作过程 ,进而提出确保换相成功的注意事项。

On the basis of the brief introduction to TEM-Ⅱ Transmitter of transient electromagnetic method and it's working principles.The dissertation concludes that voltage and current of TEM-Ⅱ Transmitter of transient electromagnetic method has phase conversion .process with inductance loaded,IGBT IGBT bridge circuit power has phase conversion process and issues on releasing imaginary power in the course of power change.In the dissertation the author analyzes the phase conversion rule of loaded voltage and current,circuit of the eleasing imaginary power,attaching importance to the detailed study of phase conversion process of IGBT bridge current composed of wholly controlled parts IGBT,based on the three working style of TEM-Ⅱtransmitter with inductance loaded.Then it presents the individual wave diagrams of voltage and current according to the experiment,then gives the dawns of current direction in the first phase conversion and on-off action process in the second phase conversion,Finally,it stresses several things should be noticed to ensure successful phase conversion.