Now showing 1 - 7 of 7
  • Publication
    Power balance provision through co-ordinated control of modern storage heater load
    (Energynautics GmbH, 2013-10-24) ;
    Operational inflexibility due to wind variability at high penetration levels can be mitigated through flexible demand. However, most flexible loads entail a subsequent short-term higher energy payback and aggregated load coincidence. Storage heaters operating on a dual tariff, that typically charge during a fixed time window, can be considered as distributed thermal storage without an associated energy payback period. Modern storage heaters have improved heat retention, the capability to estimate their required charge, two way communication and local frequency measurement. Storage heating load currently exists in the system, making it more eminently suitable as bulk energy source/sink. This paper presents the use of modern storage heaters to accommodate higher levels of wind integration. A technical assessment of the capability of such load to provide reserves is also presented. Two types of heaters, with different capabilities and associated communication infrastructure requirements are considered for analysis. The results are demonstrated on a detailed single bus model of the 2020 Irish power system.
  • Publication
    RoCoF-Constrained Scheduling Incorporating Non-Synchronous Residential Demand Responsee
    Demand response has the potential to provide a multitude of operating reserve categories. However, if integrated at scale, the non-synchronous nature of most demand response sources must be recognised within the operational rules of low inertia power systems. Here, a candidate non-synchronous reserve resource is considered within the scheduling and frequency stability time frames. It is shown that a detrimental impact on the post-contingency rate of change of frequency (RoCoF) can arise, potentially requiring the development of system operator policies to ensure that security standards are not compromised, as the volume of reserve available from non-synchronous reserve resources increases. A commitment-and-dispatch RoCoF constraint within scheduling procedures is proposed, which is independently verified using time domain simulations.
      581Scopus© Citations 31
  • Publication
    Provision of flexibility at high wind penetration levels using modern storage heater load
    Modern storage heaters can facilitate higher levels of wind generation on the system by mitigating the effects of wind variability and uncertainty. This paper presents a coordinated control strategy for modern storage heater load to reduce conventional plant ramping and cycling requirements. Control practices and mechanisms required to utilise storage heater load for reducing system net load variability have been presented. The communication update rate to the heaters has been shown to impact conformance to the control objective. Acknowledging the impracticality of individual appliance control, a clustering scheme has been proposed to reduce the overall communication requirements. Heater load shaping mechanisms have also been presented to provide real-time system ancillary services at high wind penetration levels.  
      355Scopus© Citations 2
  • Publication
    Analysing the impact of large-scale decentralized demand side response on frequency stability
    Advances in communications technology, higher penetration rates of renewable energy and an evolution towards smarter electrical grids are enabling a greater role from demand side response (DSR) in maintaining power system security and reliability. The provision of primary operating reserve (POR) from domestic loads through a decentralised, system frequency based approach is discussed. By considering a range of system configurations (generation mix, system generation and load) and control strategies, this paper endeavours to answer critical questions concerning the large-scale roll out of decentralised DSR, including the following: what are the implications of DSR resource seasonal variability on system operation and performance following the loss of a large infeed/load? Do increased load coincidence and energy payback phenomena have the potential to significantly impact system frequency recovery? How do DSR controller hardware characteristics influence the provision and effectiveness of reserve delivery? What are the repercussions of a 'fit and forget' approach to decentralised control from flexible load on frequency stability as the technology penetration increases? Can DSR be directly substituted for conventional reserve sources while recognising its post-event recovery period? Residential customer behaviour, seasonal effects and the diversity of individual device characteristics are recognised in a detailed thermodynamic flexible load model which is integrated with a detailed power system model to perform the analysis.
      205Scopus© Citations 36
  • Publication
    Challenges in utilisation of demand side response for operating reserve provision
    Utilisation of flexible demand to provide contingency reserves is generally considered beneficial to power systems, and can be a key enabler for ambitious renewable energy penetrations. Detailed techno-economic analysis of reserve provision from flexible demand is considered in this paper. A unit commitment/economic dispatch problem is set up that recognises demand side response (DSR) as a source of primary operating reserve (POR). Dispatch schedules are then verified with frequency stability assessments to quantify any changes in system performance. It has been demonstrated that while generally beneficial, utilization of DSR does not always improve system performance. Factors such as changes in plant dispatch (largest in-feed contingency can be greater) and flexible demand resource variability have been shown to limit the benefits of DSR under certain conditions. Actual activation of DSR for POR is also shown to compromise network integrity in some cases. All results are demonstrated using the Irish power system.       
  • Publication
    Impact of large-scale demand side management on system frequency policy - a case study
    Demand side response (DSR) has gained significant interest due to the time-varying and uncertain nature of renewable energy, and the challenges associated with integrating renewable technologies into power systems. DSR is considered as a fundamental component of the emerging smart grid paradigm and is seen as a potential means to achieve higher renewable targets across the globe. It is, therefore, imperative to explore the potential implications of wide-scale DSR on system operation. In particular, the impact of large-scale coordinated load switching on potential operational limits, while considering different DSR-based magnitudes and ramp rates, is considered here. The All Ireland System (AIS) projected for the year 2020, and characterised by a significant penetration of wind power has been used as a test system in the presented research study.
  • Publication
    Demand side management potential of domestic water heaters and space heaters
    (Elsevier - International Federation of Automatic Control (IFAC), 2012-09-02) ;
    Demand side management (DSM) is a viable strategy for facilitating integration of renewable energy into power systems. The demand resource from water and space heating can be used to reduce or delay system demand peaks, and in combination with other flexible loads, reshape the aggregate demand profile and manage system ramping. In this paper, the aggregate power draw profiles for heat pump based water heating and under floor space heating systems for the Irish domestic sector have been synthesized and the effects of daily and seasonal variations, the type of dwelling and control / usage patterns on demand are discussed. The results show a significant seasonal and daily variation of the demand profile for water and space heating, indicating its viability as a DSM resource on the Irish power system, but also the challenges of operation.