Study And Analysis Of AC-AC Cuk Converter

Recently, Regulated Power Supply integrated of modern power electronics technology, control technology and information technology, grows fast. The type of AC-AC Regulated Power Supply has a relatively simple circuit structure because of omitting the intermediate DC link, and has become to be an important research direction. This paper borrows the ideas of DC_Cuk converter and puts forward a new type of direct AC-AC converter named AC_Cuk converter. It abandons ferromagnetic devices and has the advantages of small volume, low cost, quick response speed, can realize the electrical isolation of input and output and so on. So the market prospect of the new AC converter is very broad. Therefore, it will be highly significant to study the AC_Cuk converter.Firstly, the paper elaborated in detail about the classification and principle of current Regulated Rower Supply and according to the development of hot spots and market demand to put forward the new AC_Cuk converter. The paper also studied the related theory, including the principle of AC transforming, reducing the output ripple and decreasing power switching losses and realized the simulation by using the software of Simulink.Secondly, to realize voltage stabilization, this paper focused on the research of the closed-loop controlling strategy of the converter. In the paper, the author established the mathematical model of converter by using state-space equations, and gets to obtain equivalent model of small signal disturbance about the AC_Cuk converter by calculating the mathematical mode. Through calculating small-signal disturbance model could obtain the Bode graph of opened-loop system by which to analysis the frequency and phase of the characteristic, then use PI compensator to correcting the system.Again, this paper finished the designs including device selection, parameter selection and circuit structures of the main circuit of the AC_Cuk converter, PWM signal generation and signal conditioning circuit, IGBT isolation drive circuit etc, andalso designed signal acquisition and processing circuit, DSP digital control circuit,Calendar clock module, A/D and D/A module etc. The paper also compiled the software flow in each part of the digital control system.At last,this paper made an AC_Cuk converter prototype which measurement data is the same as theoretical analysis and simulation results. The output waveform has perfect sinusoidal and has not crossover distortion which is satisfactory. The result verified this new converter can realize the function of AC-AC. At the end of the article, we carried on the forecast of the next work in future.