A study on LQG/LTR control for damping inter-area oscillations in power systems

Published versio

Optimised PID control for tilting trains

Nulling-type tilt control in tilting railway vehicles, i.e. SISO (Single-Input-Single-Output) control us- ing non-precedent sensor information for lateral acceleration and tilt angle, suffers from performance limitations due to the system’s non-minimum phase characteristics Zolotas & Goodall (2000). From a engineering point of view this is due to the suspension’s dynamic interactions and the sensor information used for feedback control. This paper revisits SISO PID-based nulling-type tilt control design (hereby referred to as “economical tilt control”) and rigorously studies its design via optimization to improve system performance. The strong coupling between the roll and lateral dynamic modes of the vehicle body is shown and the performance limitations using conventional control highlighted. PID controllers are de- signed to illustrate different levels of tilt performance regarding the deterministic (curving acceleration response) and stochastic (ride quality) with the latter being a bounded constraint. With novel contri- bution to use of PID control in the tilt control application with rational transfer functions, particular emphasis is placed on the practical aspects of the tilt dynamics within the design framework via detailed simulation results

Stability control of a railway vehicle using absolute stiffness and inerters

Work presented in this paper studies the potential of employing inerters - a novel mechanical device used successfully in racing cars - in active suspension configurations with the aim to enhance railway vehicle system performance. The particular element of research in this paper concerns railway wheelset lateral stability control. Controlled torques are applied to the wheelsets using the concept of absolute stiffness. The effects of a reduced set of arbitrary passive structures using springs, dampers and inerters integrated to the active solution are discussed. A multi-objective optimisation problem is defined for tuning the parameters of the proposed configurations. Finally, time domain simulations are assessed for the railway vehicle while negotiating a curved track. A simplification of the design problem for stability is attained with the integration of inerters to the active solution