HEMS-enabled transactive flexibility in real-time operation of three-phase unbalanced distribution systems

Abstract

This paper proposes a coordinated two-stage real-time market mechanism in an unbalanced distribution system which can utilize flexibility service from home energy management system (HEMS) to alleviate line congestion, voltage violation, and substation-level power imbalance. At the grid level, the distribution system operator (DSO) computes the distribution locational marginal prices (DLMP) and its energy, loss, congestion, and voltage violation components through comprehensive sensitivity analyses. By using the DLMP components in a firststage optimization problem, the DSO generates two price signals and sends them to HEMS to seek flexibility service. In response to the request of DSO, each home-level HEMS computes a flexibility range by incorporating the prices of DSO in its own optimization problem. Due to future uncertainties, the HEMS optimization problem is modeled as an adaptive dynamic programming (ADP) to minimize the total expected cost and discomfort of the household over a forward-looking horizon. The flexibility range of each HEMS is then used by the DSO in a second-stage optimization problem to determine new optimal dispatch points which ensure the efficient, reliable, and congestionfree operation of the distribution system. Lastly, the second-stage dispatch points are used by each HEMS to constrain its maximum consumption level in a final ADP to assign consumption level of major appliances such as energy storage, heating, ventilation and airconditioning , and water heater. The proposed method is validated on an IEEE 69-bus system with a large number of regular and HEMS-equipped homes in each phase.

Developments and Challenges in Local Electricity Markets: A Comprehensive Review

“…x x x [120] x x x [121] x x x [122] x x x x [123] x x x x [124] x [125] x [81] x x x x [126] x x [127] x [128] x x [47] x x [129] x x [130] x [131] x x [132] x x x [133] x x [118] x x [134] x x [135] x x [136] x x [137] x x x [138] x x x [139] x x x [140] x x [141] x x x [142] x x x [86] x x x x [143] x x x [144] x x x [145] x x x [146] x x x [147] x x x…”

“…An important next step is to incorporate grid challenges into the mathematical formulation, either directly or indirectly, ensuring that the imposed impact on the physical layer is feasible and does not cause further issues, as presented in Section II. x x [107] x x x [108] x x [109] x x [110] x x [112] x x [115] x x x [116] x x x [117] x x x [119] x x x [120] x x [121] x x x [122] x x x [81] x x [128] x x [129] x x x [133] x x [134] x x x [137] x [138] x x x [139] x x x [140] x [141] x x x [142] x x x [86] x x x x [143] x x [144] x…”

Blockchain-Enabled Transactive Home Energy Management Systems in Distribution Networks

“…We consider an unbalanced distribution system, shown in Fig. 2, which serves a different number of homes in each phase of its three-phase nodes [23]. Residential homes on every phase are of either regular or smart (HEMS-equipped) type.…”

“…The DSO can, however, solve its first stage optimization problem without any need for demand or supply bids, and can maximize the social welfare by dispatching as much power as demanded and allowed by the grid constraints. Distribution locational marginal price (DLMP), values that are composed of energy, losses, congestion, and voltage violation components of each node at each timeslot, are computed using the first-stage optimization solution and sensitivity analysis [15], [23][24][25]. When congestion or voltage violation prices are shown, signaling the existence of an operational issue, the DSO immediately seeks flexibility service from HEMSs to alleviate the issues while maintaining three-phase power-balance at the substation node.…”

Stochastic home energy management system via approximate dynamic programming

“…Market analysis studies indicate that there is growing consumer awareness of the potential of HEMS to help manage home energy consumption and energy costs [2 ]. HEMS can further serve as a demand response (DR) management system at the household level with the ability to manage controllable loads and defer shift‐able loads to minimise network congestion and violations under peak load conditions by providing flexibility services to the distribution system operators [3 ].…”