This paper describes the behaviour of digitally controlled thyristor converter systems and includes the effects of variable firing angle and feedback filter configuration. System stability has been analysed by using the perturbation method, and system responses for both reference and disturbance signals have been obtained using z-transforms. System optimisation has been achieved by careful choice of the regulatable parameters. Both theoretical analysis and experimental results indicate that closed-loop control with unity feedback can have good system quality, with easy optimisation.
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References
1.
Fallside, F. and Farmer, A.R.1967. 'Ripple instability in closed-loop control systems with thyristor amplifiers', Proc IEE, 114 (1), 139-152.
2.
Fallside, F. and Jackson, R.D.1969. 'Direct digital control of thyristor amplifiers', Proc IEE, 116 (5), 873-878.
3.
Jury, E.I.1964. Theory and application of the z-transform method, Wiley, New York.
4.
Kuo, B.C.1980. Digital control systems, Holt, Rinchart and Winston, New York.
5.
Luo, F.L. and Hill, R.J.1984. 'Influence of firing angle on system stability area of thyristor bridge converters', Trans IECON'84, Tokyo, Japan, 733-738.
6.
Luo, F.L. and Hill, R.J.1985. 'Multiple sampling and digital signal processing technique for digitally-controlled thyristor converters', Proc 5th PEUB'85, Budapest, Hungary, 1—12.
7.
Luo, F.L. and Hill, R.J.1985a. 'Disturbance response technique for digital control systems ', IEEE Trans, IE-32 (3), 245-253.
8.
Luo, F.L., Jackson, R.D. and Hill, R.J.1985. 'Digital controller for thyristor current source', Proc IEE, 132, Pt. B, (1), 46-52.
9.
McMurray, W.1982. 'The closed-loop stability of power converters with an integrating controller', IEEE Trans, IA-18 (5), 521-531.
10.
Murphy, G.J.1966. 'Basic automatic control theory', Van Nostrand, New Jersey.
11.
Muth, E.J.1977. Transform method with applications to engineering and operation research, Prentice-Hall, New Jersey.
