In Pursuit of New Real-Time Ancillary Services Providers: Hidden Opportunities in Low Voltage Networks and Sustainable Buildings

Abstract

Following recent EU directives, the penetration of smart sustainable buildings (SSBs) in low voltage (LV) networks is expected to drastically increase. This open ups opportunities for developing novel frameworks to coordinate the provision of ancillary services (AS) stemming from SSBs. In pursuit of investigating the extent of the previously untapped potential of LV networks, this work proposes, for the first time, the development of an SSB-driven MV-LV coordination framework for the provision of AS, inspired by industrial HV-MV AS schemes from the European landscape. Analytical formulations of passive and active ancillary schemes are first presented, in the form of mixed-integer nonlinear programming problems. Analytical reformulations and approximations are then proposed, to derive computationally lighter mixed-integer linear programming models. The real-time management of AS provision is based on a novel 3-stage, model predictive control approach, driven by the collaboration between distribution system operator and SSBs, the latter considering environmental and phase balancing aspects in their optimizations. Emergency situations with network violations are also considered. The approach is validated, tested, and compared to its predecessor, i.e., its past, cruder version, on a multi-feeder LV network containing different types of SSBs.

Smart Sustainable LV Networks providing Ancillary Services under Uncertainty: A Joint Chance-Constrained Model

“…Aside from their manifold environmental and end-user benefits, SSBs can drastically increase the available flexibility in DS, contributing to relieving congestions and voltage issues [2]. When the flexibility potential of DS outweighs its needs, the "leftover" flexibility amount could very well be deployed in a more sophisticated manner, allowing for the provision of upstream ancillary services (AS), i.e., to higher voltage levels [3].…”

“…Research focuses mainly on how DSOs can support the TSO during planning and operation [5], [6]. However, we recently entertained the idea of adapting AS schemes, originally proposed in the scope of TSO-DSO cooperation, to the MV-LV interface [3]. While the idea of "harvesting" flexibility in a bottom-up manner, i.e., starting from the LV level, is not new per se [7], LV networks are often alarmingly simplified.…”

“…The hypothesis of [3] was that if LV networks behave in a supportive manner for the MV network, without enforcing direct controllability, MV networks could gradually shift from self-management towards constructing more viable TSO-DSO coordination frameworks. Preliminary results in [3] indicate merit in the idea.…”

“…The hypothesis of [3] was that if LV networks behave in a supportive manner for the MV network, without enforcing direct controllability, MV networks could gradually shift from self-management towards constructing more viable TSO-DSO coordination frameworks. Preliminary results in [3] indicate merit in the idea. It might thus be that MV-LV cooperation does not require significant sophistication, and that conforming to pre-decided technical standards might be sufficient.…”

“…Naturally, providing AS presupposes freedom from internal issues. In [3], the LV network was being managed in real-time, without prior operational planning. This common assumption increased the likelihood of being driven to emergency mode, i.e., responding to technical violations, thus missing out on opportunities to provide upstream AS.…”