Research And Design Of Frequency - Modulated Constant Energy Pulse Power Synthesis Circuit

Today’s power electronic technology is mainly through PWM (Pulse Width Modulation) method to complete the poweif converter main circuit, however it has following deficiencies:firstly, during the Power Switch Devices’opening and shut off, the voltage and current are not synchronized,the main switch devices have to bear highly switching loss of instantaneous power, and with the increasing of power converter and improvement of the chopping frequency, this loss also increases, thus making the highest chopping frequency PWM mode is restricted; secondly, the main circuit of PWM converter’s energy transmission mode is voltage transmission, so it need to set up the velocity in the main loop of the converter fault protection to solve the problem of the output load and the output short circuit, due to the velocity fault protection circuit at the instant of shut off, the value of di/dt in the circuit is very large, the di/dt value and the conductor of stray inductance are Interacting with each other, so it produce a high peak voltage in the circuit, the spike voltage and power supply voltage in series is very easy to breakdown the power switch device; thirdly, if the power’s output requires constantly (just as no matter the value of the load how to change, the output power is constant), only by voltage and currents’double closed-loop feedback control can achieve it in the existing technology, but this method is so complex that it is very difficult to implement the control circuit.This project is commissioned by the enterprise development project, by the query, there is no meet the requirements of domestic products at present, therefore, only through our own research and development can we work out this problem, but it need high technical requirements and it is also very difficult, so this paper is a part of the process of the completion of the project.Paper’s main innovation points lies in:(1) according to the characteristics of power transmission principle of electronic circuit and the goal of the project requirements, this paper proposes a new method that is a single channel frequency modulation type constant energy for pulse power synthesis, this new method make the construction of the application system can realize the condition of constant power output characteristics in the opening loop, at the same time can guarantee the output under the condition of no distortion effectively improve the circuit chopping frequency, reduced the volume of the whole circuit; (2) To overcome the limitation of DSP’s speed, this paper use the simulation method to control the power main circuit implementation; (3) In order to overcome the problem that the traditional linear voltage - frequency conversion circuit area are not wide enough, this paper put forward a new structure of symmetric of high speed and high precision voltage - frequency conversion circuit; (4) to complete the whole system of the principle of control circuit and main circuit’s schematic diagram and PCB’s design and welding, detection of debugging and waveform indicators and eventually reached the requirements of the project.This paper briefly discuss the current situation and existing problems of power electronic technology, and the thesis involves knowledge was introduced in brief, on this basis, the principle of high speed and high precision voltage - frequency conversion circuit are discussed, as well as the constant energy chopper type power synthesis system principle of the circuit and the design of the circuit are detailed analyzed.