Governor

Abstract: This paper provides a tutorial overview of reference governors and command governors, which are add-on control schemes for reference supervision and constraint enforcement in closed-loop feedback control systems. The main approaches to the development of such schemes for linear and nonlinear systems are described. The treatment of unmeasured disturbances and parametric uncertainties is addressed. Generalizations to extended command governors, feedforward reference governors, reduced order reference governors, parameter governors, networked reference governors, decentralized reference governors, and virtual state governors are summarized. Examples of applications of these techniques to automotive systems are given. A comprehensive list of references is included. Comments comparing reference and command governor approaches with Model Predictive Control and input shaping, and on future directions in reference and command governor research are included.

Abstract: The fuel cell oxygen starvation problem is addressed in this paper using a robust load governor. By regulating the current drawn from the fuel cell, the pointwise-in-time constraints on the oxygen excess ratio and on the oxygen mass inside the cathode are strictly enforced to protect the fuel cells from oxygen starvation. The load governor is designed using a nonlinear reference governor approach. Parameter uncertainties such as those due to imperfect controls of temperature and humidity are handled in the load governor design using a novel approach based on sensitivity functions. Simulation results are included to demonstrate the effectiveness of the proposed scheme. The results are compared with those of a linear filter which has been proposed in the prior literature to achieve similar goals.

Abstract: This paper presents an approach for generator model validation based on the measurements taken at the point of interconnection. The approach is initially applied for The Dalles powerhouse, where the simulated and actual governor responses were found different. Governor tests and monitoring were performed and resulted in model revisions. The approach also resulted in improvements of John Day turbine-governor models. Grand Coulee governor response was validated and found adequate. Based on the project experience, a process for generator model validation is proposed.

Abstract: v. 1. 1628-1641.--v. 2. 1642-1649.--v. 3. 1644-1657.--v. 4, pt. 1. 1650-1660.--v. 4, pt. 2. 1661-1674.--v. 5. 1674-1686.