Showing papers by "Mark J. Balas published in 1998"
12 Jan 1998
TL;DR: In this paper, a new control problem arises in active control of variable speed horizontal axis wind turbines for electric power generation, which must cause the plant output to track a linear function of the disturbance.
Abstract: A new control problem, which arises in active control of variable speed horizontal axis wind turbines for electric power generation, is discussed. Feedback control of a linear plant, which is persistently disturbed, must cause the plant output to track a linear function of the disturbance. Theory, which will guarantee stable disturbance tracking, is developed using the method of aggregation. These results are related to the better known Disturbance Accommodating Control Theory and applied to create a tip speed ratio tracking controller for a horizontal axis wind turbine generator.
85 citations
TL;DR: In this article, the authors present stability bounds in both the time and frequency domains for infinite-dimensional systems, and show that the frequency domain approach appears to yield more easily tested stability conditions than the time domain approach.
22 citations
12 Jan 1998
TL;DR: In this paper, a simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics, i.e., the deviation of the rotor speed from the desired speed and the motion of the actuator.
Abstract: Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three regions of operation. This paper focuses on controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative (PID) controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship of the two opposing metrics is easily visualized. 2 refs., 9 figs.
19 citations
21 Jun 1998
TL;DR: Using an FEM, it was shown that all linear flexible structures have convergent second-order observers, but that some are unnatural, involving a corrector term obtained from a filter as mentioned in this paper.
Abstract: Using an FEM, it is shown that all linear flexible structures have convergent second-order observers, but that some are unnatural, involving a corrector term obtained from a filter.
16 citations
TL;DR: In this article, the authors presented a preliminary modeling and control design study of an asymmetric teledesic communication satellite (TCS) and developed a dynamic satellite model and design a corresponding controller based on this model.
2 citations