CAJ | 학술논문

为改进红外锁相热成像检测中的热调制激励效果，提高系统集成和使用性能，引入了数字功率控制技术。以可控硅为功率元件，推导控制角与功率的关系。以正弦调制激励为例，通过数值计算求解控制角随时间的变化规律，基于数字电路设计导通角控制算法和实现方法建立了实验平台并进行了实验验证和对比。结果表明：该方法的功率控制精度高，热成像波形的保真度明显优于常规激励技术，体积和结构也得到改善，电磁安全性满足要求，可以更好地应用于红外锁相热成像检测中。
위개진홍외쇄상열성상검측중적열조제격려효과，제고계통집성화사용성능，인입료수자공솔공제기술。이가공규위공솔원건，추도공제각여공솔적관계。이정현조제격려위례，통과수치계산구해공제각수시간적변화규률，기우수자전로설계도통각공제산법화실현방법건립료실험평태병진행료실험험증화대비。결과표명：해방법적공솔공제정도고，열성상파형적보진도명현우우상규격려기술，체적화결구야득도개선，전자안전성만족요구，가이경호지응용우홍외쇄상열성상검측중。
To improve the integration level and performance of modulated heat excitation source, a new digital power control technology was developed for application of lock-in thermography in NDT. Silicon controlled rectifier(SiCR) was used as a power output controlling unit, and a relationship between SiCR’s control angle and output power was also obtained. Taking the sinusoidal signal as the excitation source, the changing rule of control angle over time was achieved by using numerical calculation while the control algorithm and implementation method of the conduction angle were designed based on digital micro processing circuit. The experimental platform was thus built up and the comparison experiments were carried out. The results show that the present approach can gain higher precision of power control, better fidelity of thermal waveform and preferable equipment in structure and size. Moreover, its electromagnetic safety can meet the relevant requirement. Therefore, better results can be expected by using this method in the infrared lock-in thermography.