| The essence of high voltage and large current discharge technology is energy compression. In the way of energy storage with capacitors or inductances, the energy is released to a pulsed power load through the discharge circuit during an extremely short time, which causes pulsed power, and this power is always more than 106W.When high voltage and large current discharge takes place under water, drastic explosion effect is caused, so that great pulse pressure wave which is caused by the explosion effect spreads in the water, and acoustic pulse is generated. All is the process that underwater discharge generates acoustic pulse.In order to detect some special objects such as hollow submarines in military field, an underwater acoustic source is required, whose frequency bandwidth is in the range of (1~ 4)KHz, and the pressure peak of the acoustic pulse is more than !MPa. A great deal of deep research shows that this kind of acoustic source can be generated by the means of large current pulse discharge under water. The main content of this paper covers how to develop this kind of acoustic pulse generator.The development of this equipment includes two main parts, one is charge circuit system, the other is main discharge circuit system.Two charge ways are commonly taken in charge circuit, charge with constant voltage and charge with constant current. Comparatively, the former has relatively higher charge efficiency, so it is frequently used in the technology of high voltage and large current discharge. The interval between charge and discharge is required to be 2~4 second, this requirement demands greatly high charge efficiency, so that the charge system takes the way of three-phase L-C resonance charge with constant current, the output of the resonance circuit can charge the capacitor set fast through the voltage-ascent transformer and silicon converter equipment. In the charge circuit, identity of some main components' parameters is also the greatly important part during the circuit design. Through presenting numerical analysis of charge circuit and considering extract parameters required for the whole generator, the selection of components can be accomplished.In the main discharge circuit, the highest discharge voltage is demanded to be 45KV and the acoustic pulse peak must be more than !MPa, so two capacitor sets with two sparker discharge switch sets should be used, through two sets of transport cable which are connected with underwater discharge electrode, capacitor sets can realize discharge. Because the main discharge circuit has serious requirement for circuit inductance, when select main components' parameters and conduct architecture design, this factor must be considered. At the mean time, it calls for high requirements for electrical connection between circuit components and the protection of components. In the paper, according to different components different solutions are also presented.Based on this design scheme, the results of former experiments in lab and experimental test on sea have proved this design is practical, the selection of parameters is reasonable andthe electrical connection circuit is corrective, the parameters perfectly reach the performance requirements. However some parts such as measure and control module, equipment protection part should be adjusted and promoted.A pulsed power acoustic source generated by the high voltage and large current underwater discharge has many priorities, it is steady, reliable and safe, its operation parameters are variable and its operation is repeatable. Because of these priorities, this kind of technology application is supposed to be greatly prospective, especially in military field.As a corporation between Dalian University of Technology and Dalian 760 research institute, this paper gives a complete design and development scheme of the underwater sparker acoustic source, meanwhile, the theoretical basis of the design and the practical test data on sea are also presented.
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