摘要
瞬变电磁法(transient electromagnetic method,TEM)要求激励脉冲电流下降沿高度线性、稳定,并具有关断延时短、无电流过冲和良好的正负向一致性等特点,全桥电路可用于产生双极性电流脉冲,但在母线电压低、负载电感量大、回路电阻小的情况下,脉冲的前后沿波形形状难以满足瞬变电磁法要求。提出恒压钳位电流陡脉冲发射电路,讨论了电路参数计算、能量回馈和损耗等问题,采用仿真和实验方法,与改进RCD缓冲器、电感能量衰减器(inductance energy decay device,IEDD)和准谐振发射电路作了对比分析。结果表明,推荐电路关断延时短,下降沿线性度高且斜率可调,电路参数最优解与负载、电源和输出电流不相关,改善了上升沿波形,减小了能量损耗。讨论阻断二极管位置对关断性能的影响并提出了在不同输出功率情况下的推荐方案。
Transient electromagnetic method (TEM) requires the falling-edge of transmitting impulse current to be highly linear and stable with short turn-off time, good coherence, and no current overshoot. Full-bridge converter can be applied to yield the bipolar impulse current. While under the condition of low bus-voltage, large load inductance and small load resistance, it is difficult to meet the requirement of TEM. This paper represented a constant voltage clamp pulse transmitting circuit and discussed its relative problems, such as circuit parameters calculation, energy feedback and dissipation, etc.. The proposed circuit was compared with some existing TEM transmitting circuits including ameliorated RCD, inductance energy decay device (IEDD) and quasi-resonance TEM transmitting circuits by simulations and experiments. The results show that the proposed circuit has shorter turn-off time, higher linearity and lower energy consumption, and the calculated optimal circuit parameters are independent of load, power supply and transmitting current. The influence of interdiction diode location on the performance of pulse current falling-edge was discussed, and some schemes for different output powers were proposed.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2008年第33期44-48,共5页
Proceedings of the CSEE
基金
国家自然科学基金项目(50577071)
三峡库区生态环境教育部重点实验室访问学者基金(KLVF-2007-1)~~
关键词
电力电子
电流陡脉冲
线性度
关断延时
瞬变电磁法
power electronics
steep impulse current
linearity
turn-off time
transient electromagnetic