海洋电磁发射机二级母线冲击电压产生机理及抑制

Generating Mechanism and Suppression of Impulse Voltage onSecondary Bus of Marine Electromagnetic Transmitter

电磁探测法是海洋油气资源勘探的主要方法,而海洋电磁发射机是海洋电磁探测系统的关键设备.目前海洋电磁发射机水下拖体长时间工作时,会出现开关器件损坏现象.首先分析了采用单向可控源电路的发射桥换流过程,发现发射偶极寄生电感回馈能量使二级母线产生冲击电压,增大了开关管的电压应力.然后分析了双向可控源电路的工作模式,提出一种双变量解耦控制策略,在变压器前后两级建立的模型基础上,将原来的耦合非线性系统全局线性化为两个单输入单输出系统,以此获得滑模控制器的函数关系.仿真与实验结果表明,所设计的可控源电路可以明显减小母线电容的冲击电压和开关管的电压应力,提高系统的动态性能和效率.

Electromagnetic detection is the main method of marine oil and gas resources exploration,and marine electromagnetic transmitter is the key equipment of marine electromagnetic detection system.At present,when the underwater towed body of the marine electromagnetic transmitter operates for a long time,the switch devices will be damaged.First,the commutation process of the transmitting bridge with unidirectional controlled-source circuit is analyzed.It is found that the feedback energy of the transmitting dipole parasitic inductor makes the secondary bus generate impulse voltage,which increases the voltage stress of the switch devices.Then,the operating mode of bidirectional controllable source circuit is analyzed,and a dual variable decoupling control strategy is proposed.Based on the model established at the front and back of the transformer,the original coupling nonlinear system is globally linearized into two single input single output systems,so as to obtain the functional relationship of the sliding mode controller.The simulation and experimental results show that the designed controllable source circuit can significantly reduce the impulse voltage of bus capacitor and the voltage stress of switch device,and improve the dynamic performance and efficiency of the system.