Low-pressure And Large-current Switching Power Supply Design Based On The PWM

In the information age, the changing process of development, electronic technology rapid progress, backward industrial equipment and the new development trend of green energy and environment caused by the development of switch power industry, is imperative. The design of the power system of investigation of high frequency switching power supply and utilization of electric power system was designed in the practical application of high frequency switching power supply, using technology mature pulse width modulation technology, PWM control signals generated by the integrated chips from power system, UC real-time sampling of the output voltage feedback signal, as the main circuit, control circuit and passed between transformer or photoelectric couplers isolation. Through the experimental results show that this system can get energy efficient, stable current and voltage output and meet the design requirements.The main features of this topic has four aspects:First, the application block BPCP technology, rectifying the three-phase fill in the rectifier circuit based on conventional rectifier circuit, with branch, b circuit to work together, the harmonic wave in the power grid effectively solve problems, make this a design more energy efficient, green environmental protection.Second, the current-mode PWM. Through the internal current loop feedback, can improve the response speed of system, make the switch tube signal output signal can follow the rapid changes, to make up for the single voltage source PWM control mode shortcomings.Third, the slope compensation technology. Sampling current and former current compensation current in the ratio of superposition slope in about 2/1, in about 390v exceeds 0.5 and continuous mode can restrain system instability characteristics.Fourth, using a nanometer crystal core shell the isolated transformer, leakage of windings are small, core low loss, and have the advantages of small size light weight and reduce the machine's size and weight.In the end, system, realize the machine with debugging loading operation, efficiency in 90%, can get the 1200A 15V/stable output, performance meet the design requirements. This design has low voltage high current, low power consumption, high efficiency and energy saving outside the characteristics of applied circuit is simple, can be used in electroplating, transportation, power generation, etc.