Research On Control Circuit Of Power Converter Circuit With Open - Loop Dynamic Impedance Self - Matching Function

PWM (Pulse Width Modulation) technology is a modern power electronic converter technology whose is the most widely used technology, its widely used in small and medium-power DC/DC buck-boost DC converter, AC/DC controlled rectifier, full power range DC/AC inverters, medium-power and high-power AC motor’s AC/AC soft start and other fields.But since the pwm technology uses voltage Chopper work,so,in terms of medium-power and high-power output waveform, using passive filtering methods to filter out their side of the higher harmonics as possible is quite difficult,so far,using PWM to achieve high-fidelity audiopower waveform output,Previous studies but progress is slow.This paper is preliminary research results from other units commissioned development projects,Project requirements achieve a high performance requirements, continuous a wide range of underwater resources detection equipment research and development,Its technical requirements are as follows:output waveform is Standard sine wave;frequency need40Hz100kHz continuously adjustable;load impedance4Ω～1000Ω continuously adjustable;In the frequency range and the load impedance required for a constant output power of1KW, and within the full range of the waveform distortion less than1%.Retrieved from the related products and technologies, the current in the country do not meet the requirements of similar products.And in existing technology, traditional analog power amplifier circuit or PWM inverter circuit must be possible using transformers to achieve impedance matching,but the tricky question is, can only be resolved transformer block-style jump point match, and the objectives requirements of the full range of power matching which frequency changes continuously and impedance changing conditions.Therefore, we can say that under current technology is difficult to fully achieve the goals.Based on the above state of the art, this paper discusses the basic problems of the prior art,proposed and demonstrated a method in theory called the constant energy pulse frequency modulation converter new methods and its control technology,using high-power and high-speed FET constructed main circuit system, using DSP dashboard builts controlling circuit, using optocouplers builds pulse isolation links,achieve output signal tight follows the input signal,found completed the power converter circuit,Not only has the objective requirements of the open-loop dynamic impedance matching function,and compared with the traditional PWM inverter circuit,having all the main switching devices are in soft-switching state and in direct control of fully digital signal,etc.Therefore, the circuit efficiency is more higher.From the experimental results,the circuit’s designe to meet the objectives and requirements,and demonstrated the theory of the implementation is feasibility.Firstly, the paper is for a brief introduction about the power electronic converter technology,pointed out the advantages of PWM technology and some problems,discusses the basic knowledge involved in this research project,Also proposed a theoretical constant energy chopper axle and constant power pulse tandem synthesis waveform of the theory and a detailed analysis and derivation,then the actual circuit of the entire system is analyzed,details of the control circuit’s selecting for all devices and details of the control signal generation mode and control of the process,finally, experiments performed by the system,combined with the experimental results and associated waveforms are verified the feasibility of the system.