Noise and Parameter Heterogeneity in Aggregate Models of Thermostatically Controlled Loads
Salman Nazir, Ian Hiskens

Citation
Salman Nazir, Ian Hiskens. "Noise and Parameter Heterogeneity in Aggregate Models of Thermostatically Controlled Loads". IFAC World Congress, IFAC, July, 2017.

Abstract
Aggregate models are used in the analysis and control of large populations of thermostatically controlled loads (TCLs), such as air-conditioners and water heaters. The fidelity of such models is studied by analyzing the influences of noise and parameter heterogeneity on TCL aggregate dynamics. While TCLs can provide valuable services to the power systems, control may cause their temperatures to synchronize, which may then lead to undesirable power oscillations. Recent works has shown that the aggregate dynamics of TCLs can be modeled by tracking the evolution of probability densities over discrete temperature ranges or bins. To accurately capture oscillations in aggregate power, such bin-based models require a large number of bins. The process of obtaining the Markov state transition matrix that governs the dynamics can be computationally intensive when using Monte Carlo based system identification techniques. Existing analytical techniques are further limited as noise and heterogeneity in several thermal parameters are difficult to incorporate. These challenges are addressed by developing a fast analytical technique that incorporates noise and heterogeneity into bin-based aggregate models. Results show the identified and the analytical models match very closely. Studies consider the influence of model error, noise and parameter heterogeneity on the damping of oscillations. Results demonstrate that for a specific bin width, the model can be invariant to quantifiable levels of noise and parameter heterogeneity. Finally, a discussion is provided of cases where existing bin models may face challenges in capturing the influence of heterogeneity.

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Citation formats  
  • HTML
    Salman Nazir, Ian Hiskens. <a
    href="http://www.cps-forces.org/pubs/230.html"
    >Noise and Parameter Heterogeneity in Aggregate Models of
    Thermostatically Controlled Loads</a>, IFAC World
    Congress, IFAC, July, 2017.
  • Plain text
    Salman Nazir, Ian Hiskens. "Noise and Parameter
    Heterogeneity in Aggregate Models of Thermostatically
    Controlled Loads". IFAC World Congress, IFAC, July,
    2017.
  • BibTeX
    @inproceedings{NazirHiskens17_NoiseParameterHeterogeneityInAggregateModelsOfThermostatically,
        author = {Salman Nazir and Ian Hiskens},
        title = {Noise and Parameter Heterogeneity in Aggregate
                  Models of Thermostatically Controlled Loads},
        booktitle = {IFAC World Congress},
        organization = {IFAC},
        month = {July},
        year = {2017},
        abstract = {Aggregate models are used in the analysis and
                  control of large populations of thermostatically
                  controlled loads (TCLs), such as air-conditioners
                  and water heaters. The fidelity of such models is
                  studied by analyzing the influences of noise and
                  parameter heterogeneity on TCL aggregate dynamics.
                  While TCLs can provide valuable services to the
                  power systems, control may cause their
                  temperatures to synchronize, which may then lead
                  to undesirable power oscillations. Recent works
                  has shown that the aggregate dynamics of TCLs can
                  be modeled by tracking the evolution of
                  probability densities over discrete temperature
                  ranges or bins. To accurately capture oscillations
                  in aggregate power, such bin-based models require
                  a large number of bins. The process of obtaining
                  the Markov state transition matrix that governs
                  the dynamics can be computationally intensive when
                  using Monte Carlo based system identification
                  techniques. Existing analytical techniques are
                  further limited as noise and heterogeneity in
                  several thermal parameters are difficult to
                  incorporate. These challenges are addressed by
                  developing a fast analytical technique that
                  incorporates noise and heterogeneity into
                  bin-based aggregate models. Results show the
                  identified and the analytical models match very
                  closely. Studies consider the influence of model
                  error, noise and parameter heterogeneity on the
                  damping of oscillations. Results demonstrate that
                  for a specific bin width, the model can be
                  invariant to quantifiable levels of noise and
                  parameter heterogeneity. Finally, a discussion is
                  provided of cases where existing bin models may
                  face challenges in capturing the influence of
                  heterogeneity.},
        URL = {http://cps-forces.org/pubs/230.html}
    }
    

Posted by Ian Hiskens on 28 Feb 2017.
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