| With the rapid development of information technology, the power supply quality of electric network has caused more and more attention。Moreover, owing to rapid increase of nonlinear or impactive loads in power system, many power quality problems will be caused, such as voltage sag, swell, asymmetry, flicker, fluctuation, harmonic and so on. In various power quality problems, voltage sags are serious dynamic power quality problems. The paper adopted a new type of voltage regulator which is both-side voltage regulator based of thyristor switch control technology, called Thyristor Voltage Regulator (TVR).Firstly, the background and signification of the TVR is introduced, and the system configuration and basic operation principles are discussed. The main configuration parameters were determined by calculation.Secondly, instantaneous reactive power theory is researched, TVR voltage sags detecting method is adopted, which is improved from rapid algorithm integrating based of dq transformation. Based on the theoretical analysis of Thyristor Switching sequence, the table of switch change is designed. By means of Zero-cross-over trigger for thyristor, trigger circuit of thyristor and protective measures are given. Signal condition circuit and isolated circuit are designed based on the core of TMS320LF2407, the software of the voltage detecting is programmed and the flow charts are given.At last, a simulation model of the three-phase four-wired TVR based on Matlab/ Simulink is established. A great deal of research on compensating voltage sag and swell of TVR are carried out in use of the methods presented in this paper. The simulation results validated that TVR meets the voltage regulation request.
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