Design And Control System Realization Of High-power Charging Power Based On PLC

With the development of defense laser weapons and increase of pulse energy, the pulsed laser system is becoming more and more important; the charging power supply of laser power is a key part of the experimental laser system, which is responsible for charging the required voltage to the laser capacitor. Early laser power basically used a voltage regulator and DC power, which was consisted of rectifier circuits, for charging the laser capacitor in control. In recent years, laser charge power adopts switching power technology, reducing the volume greatly. But it is difficult to control the power, and the reliability is low, the range of the pulse frequency obtained is limited, so the laser system can not achieve high-power pulse energy.This paper focused on high power charging power supply based on PLC and its control system, but this charging power supply was quite different with the previous ones. It contains the charging unit and a number of storage capacitors. The semiconductor switch is connected in series in discharging circuit of each storage capacitor. The charging unit pre-charge several storage capacitors to store energy, then the energy of storage capacitor transferred individually to the laser capacitor via the resonant inductor in series. The accuracy of laser capacitor charging voltage was realized via De-Q control circuit.The internal power supply uses the semiconductor switch in which latest technology is used to replace the conventional thyratron switch, making the lifespan of the power supply increase considerably. The power supply is of high efficiency, high power and high accuracy of charge voltage. In the process of charging, electromagnetic energy of the resonant inductor is 50 kJ while the engineering implementation was difficult. This thesis introduces a detailed design calculation method of the inductor.Series resonant full-bridge inverter technology and power switch soft-switching technology are applied in charging unit, which uses constant current output mode to achieve ZCT and ZVT of power switch, reducing switching losses. The author analyzes the operating characteristics and operating modes of series resonant full-bridge inverter technology, especially the influence of distribution parameters of high-frequency transformer on resonance. And the specific parameters of the design, simulation and experimental waveforms are given.Meanwhile, a detailed analysis of De-Q control circuit was given, such as specific design, simulation and experimental waveforms.The control system which uses Siemens PLC control system as the core controller is to achieve operation procedure, status indication, parameters setting and fault protection of power supply. Monitoring software developed and designed based on VB is adopted as remote control. Functional requirements of the power system in working conditions are analyzed, and the system software flow chart is designed, then the hardware and software of control systems is achieved.The test results show that high power charging power supply and its control system is reliable and stable, and the design is correct; high power charging power supply could totally charge to 3MJ and solely to 0.1MJ, and the average charging power is 1.2MW.