Research And Design Of Testing System On The Bipolar High-voltage Pulsed Power Supply For Ultraviolet Photocell

With the development of the flame detection technology, flame detectors began toemerge in the field of aviation.The ignition system of aircraft engine using ignition device togenerate a high-voltage spark to ignite the engine combustion chamber aviation fuel in theengine combustion chamber.If the ignition is unsuccessful for some reason, or the ignitionsuddenly stalled during the normal combustion for some reason.Now if you do not promptlycut off the fuel but continue to invest in the fuel, it may cause explosion for excessive fuelconcentration in the Combustion chamber. Therefore, the flame state (ignition and flameout)in the combustion chamber must be monitored.Ultraviolet flame detector has occupied an important position in the field of flamedetection with its unique advantages. Because the ultraviolet tube in the ultraviolet flamedetector is only response to ultraviolet for band of185～260nm, it isn’t sensitive to thesunlight.When the flame is burning ultraviolet in this band is very strong. In this subject theultraviolet flame detector will be used in combustor of aircraft engine for flamemonitoring.Ultraviolet photocell is core equipment in the ultraviolet flame detector. Theprinciple is that electrical signal is formed when the ultraviolet rays exposure to ultravioletphotocell, then generate electric signal.The ultraviolet photocell in this subject will be applied in the aircraft engine for flamemonitoring of ignition system. Therefore, there are stringent requirements for performance,quality and working life. This subject developed a testing system for ultraviolet photocell. It isdesigned for performance tuning, testing, and acceptance testing.During product testing andacceptance testing of ultraviolet photocell through computer control to achieve testautomation. It includes automatic control for test procedures, automatic monitoring of the testprocess, automatic acquisition of test data and print test reports automatically. The testingsystem can reduce human factors influence, improve work efficiency and enhance theaccuracy of the test results.Ultraviolet photocell test system mainly consists of the bipolar of high-voltage pulsedpower supply module, signal acquisition module, the output control module, instrumentswitching module and the system control software. During the test, the system controlsoftware is primarily responsible for the control and display data for each module. The bipolarof high-voltage pulsed power supply module is responsible to provide operating voltage of thefive ultraviolet photocell, collect voltage and current in real-time. Ultraviolet photocell haveelectric, output control module control mercury lamp power supply module to supply powerof mercury lamp so that the mercury lamp simulation of ultraviolet from flame radiation. The ultraviolet photocell received the ultraviolet, the signal acquisition module will collectfeedback voltage in real-time. The meter switch module can switch signals at the same time.The design about bipolar high-voltage pulsed power supply is core equipment for testingsystem of ultraviolet photocell. It output two-wire bipolar square wave of0～1500V. Outputvoltage and frequency are adjustable, the voltage range of error is±3%, and the frequencyrange of error is±5%.This paper has been finished, the overall debugging has also completed.The system isstable and perform excellently, fully meet the customer’s technical specifications andrequirements.It has been delivered to customers yet.