3 research outputs found
Scale Free Bounds on the Amplification of Disturbances in Mass Chains
We give a method for designing a mechanical impedance to suppress the
propagation of disturbances along a chain of masses. The key feature of our
method is that it is scale free. This means that it can be used to give a
single, fixed, design, with provable performance guarantees in mass chains of
any length. We illustrate the approach by designing a bidirectional control law
in a vehicle platoon in a manner that is independent of the number of vehicles
in the platoon
Robust Scale-Free Synthesis for Frequency Control in Power Systems
The AC frequency in electrical power systems is conventionally regulated by
synchronous machines. The gradual replacement of these machines by asynchronous
renewable-based generation, which provides little or no frequency control,
increases system uncertainty and the risk of instability. This imposes hard
limits on the proportion of renewables that can be integrated into the system.
In this paper we address this issue by developing a framework for performing
frequency control in power systems with arbitrary mixes of conventional and
renewable generation. Our approach is based on a robust stability criterion
that can be used to guarantee the stability of a full power system model on the
basis of a set of decentralised tests, one for each component in the system. It
can be applied even when using detailed heterogeneous component models, and can
be verified using several standard frequency response, state-space, and circuit
theoretic analysis tools. Furthermore the stability guarantees hold
independently of the operating point, and remain valid even as components are
added to and removed from the grid. By designing decentralised controllers for
individual components to meet these decentralised tests, every component can
contribute to the regulation of the system frequency in a simple and provable
manner. Notably, our framework certifies the stability of several existing
(non-passive) power system control schemes and models, and allows for the study
of robustness with respect to delays.Comment: 10 pages, submitte
A Loopshaping approach to Controller Design in Networks of Linear Systems
A method for designing a set of controllers to robustly stabilise a network of linear systems is presented. The method allows the design of each controller to be posed as a loopshaping problem. Critically each loopshaping problem requires only local knowledge of the overall system model to formulate, and may be solved separately. Furthermore the approach is inherently scalable, as any local changes to the network model can be accommodated through the design of the corresponding local controllers, leaving all the others untouched