Zhang Xiao-mei

The research of SPWM frequency converter 3-phase cage induction motor's variable current servo-system

In this paper, the weak harmonic voltage of SPWM frequency converter 3-phase cage induction motor variable-speed system which is single pole modulation model at carrier wave ratio N=9 and modulation degree M=0.99 employed to form completely new 3-phase cage induction motor variable current servo-system by way of amplitude control. It is our hope that the motor could be developed into existence soon and so that further tests on such system could be performed.

A new model of the variable current servo-system

A detailed calculation shows that the SPWM frequency converter of a single-polar synchronous modulation model with the carrier ratio N=27 and modulation depth M=0.99 can constitute a new-type of current servo-system controlled by the amplitude, and gives good systems performance.

Robust H/sub ∞/ fault-tolerant controller design for uncertain descriptor delay system

Robust H/sub /spl infin// fault-tolerant control of a kind of descriptor delay linear system with uncertainty and disturbance is studied. By using state feedback and observer-based output feedback, control design schemes proposed for the cases of presence of actuator failures and simultaneous presence of actuator failures and sensor failures are given. The controller can be obtained by solving generalized Riccati inequalities.

On the laconic composing law of SPWM frequency converter output line-voltage

The composing laws for output line-voltage expression of SPWM frequency converter derived previously by the authors (see CWCICIA, vol.11, p.1232-7, 1997) are discussed. The paper discusses further the six rather laconic composing laws that are of practicality.