Development Of Total Digital Airfield Dimmer

Air navigation dimmer, as the core control device of air navigation lighting system, is used to adjust the brightness and provide accurate runway position, direction, and positive guidance to make sure the pilot can land safely by eyesight at night flight or bad visibility. At present, most dimmers in the inside/outside airport used silicon-controlled thyristor as power device and adopted an analog or hybrid digital-analog control mode. Such dimmers are characterized by unsatisfactory output waveform containing a lots harmonics, bad electromagnetism compatible (EMC), and easy damage to lamps. With the development of microcontrollers and power electronic technology, a new dimmer of all-digital controlled for air navigation with high performance and low cost is desired, which is very important for improving the light control performance of airport.With an extensive investigation, combined with technical requirements a new control scheme of airport light dimmer is proposed. The total digital control of the light dimmer in the airfield is implemented based on digital signal processor TMS320LF2406A. Sinusoidal pulse width modulation (SPWM) method is applied to control Intelligent Power Module (IPM) switch state for standard sinusoidal output; firmware structure and design method of control system are also described in detail; the operating status and data of dimmer can be real-time send to single chip processor by serial communication. Human-machine interface so as to provide convenience for the user to perform a local-distance control. Malfunction alert and protection methods are proposed for the sake of ensuring dimmer operating normally.System's long-time running experiment proves that the proposed system had a very high performance and anticipated design objective is achieved.