Title :
A microprocessor-based self-adaptive trigger for thyristor converters
Author :
Liang, Han-Bin ; Zhong, Yan-Ru
Author_Institution :
Shaanxi Inst. of Mech. Eng., China
Abstract :
A digital trigger with lock-phase synchro power makes it possible to trace, automatically the change of a power network´s frequency and to ensure symmetrical phases trigger pulses. It is used for thyristor power convertors to restrain the harmful effect of harmonics on power networks. In this paper, a scheme of implementing digital lock-phase by a microprocessor is presented: the principle of digital lock-phase is discussed and a self-adaptive trigger adopting a single chip microprocessor as its core is introduced. The design of a hardware circuit and software system are also given. Finally, this paper analyzes pulse stability and the pulse loss problem, poses an effective solution measure. Because phase-locked loop synchro power is used, the symmetrical error between trigger pulses can be minimized to 0.054°. Practical application shows that this type of trigger not only saves hardware, but also has excellent properties, and the powerful ability of anti-disturbance
Keywords :
adaptive control; digital control; microcomputer applications; power convertors; self-adjusting systems; switching circuits; thyristor applications; trigger circuits; voltage control; design; digital control; hardware; harmonics; lock-phase synchro power; microprocessor; phase-locked loop; pulse loss; pulse stability; self-adaptive trigger; software; switching circuits; voltage control; Circuit stability; Converters; Frequency; Hardware; Microprocessors; Power system harmonics; Pulse measurements; Software systems; Stability analysis; Thyristors;
Conference_Titel :
Industrial Electronics, 1992., Proceedings of the IEEE International Symposium on
Conference_Location :
Xian
Print_ISBN :
0-7803-0042-4
DOI :
10.1109/ISIE.1992.279698