Achieving the dispatchability of distribution feeders through prosumers data driven forecasting and model predictive control of electrochemical storage

Abstract

Abstract-We propose and experimentally validate a process to dispatch the operation of a distribution feeder with heterogeneous prosumers according to a trajectory with 5 minutes resolution, called dispatch plan, established the day before the operation. The controllable element is a utility-scale grid-connected battery energy storage system (BESS) integrated with a minimally pervasive monitoring infrastructure. The process consists of two stages: day-ahead, where the dispatch plan is determined by using forecast of the aggregated consumption and local distributed generation (prosumption), and real-time operation, where the mismatch between the actual prosumption realization and dispatch plan is compensated for thanks to adjusting the real power injections of the BESS with model predictive control (MPC). MPC accounts for BESS operational constraints thanks to reduced order dynamic grey-box models identified from online measurements. The experimental validation is performed by using a grid-connected 720 kVA/500 kWh BESS to dispatch the operation of a 20 kV distribution feeder of the EPFL campus with both conventional consumption and distributed photo-voltaic generation.

Concurrent Voltage Control and Dispatch of Active Distribution Networks by Means of Smart Transformer and Storage

“…1) the active power flow on the MV side tracks the socalled dispatch plan, i.e., a sequence of average power consumption profile at 5-minute resolution established the day before operation [18]; 2) the reactive power injection of the MV converter is controlled to provide voltage regulation support to the MV network; 3) the voltage reference of the LV converter is controlled to provide voltage regulation to the LV network. 1) Control Problem of the MV power converter: It consists in a hierarchical control strategy where the active and reactive power injections are determined sequentially and coupled by the apparent power constraint of the converter, as described in the following.…”

“…This paper proposes a control strategy for a ST with integrated storage which has the following concurrent objectives: i) dispatching the active power flow of the underneath distribution system (composed of stochastic prosumption) according to a profile established the day before the operation, and, ii) providing voltage control on a best effort basis to both the LV network and the upper-stream MV distribution network. As detailed later, the first control objective is achieved by exploiting the design proposed in [18]. It consists in determining, the day before operation, a dispatch plan at 5-minute resolution by using prosumption forecasts and accounting for the information on the residual BESS charge.…”

Lifetime-Based Power Routing in Parallel Converters for Smart Transformer Application

“…For this analysis, a three day mission profile of an ST fed micro-grid, as shown in Fig. 6, is considered [23], [24]. First, the three converters are fed with balanced power distribution, irrespective of the initial accumulated damages, the accumulated damages and end-of-lifetimes are calculated.…”

Enhancing the provision of ancillary services from storage systems using smart transformer and smart meters

“…, P 288 ), established the day before the operation. The dispatch plan is defined using the method proposed in [6]. It consists in the additive contribution of two terms: the expected value of the prosumption 3 , generated by a forecasting tool, and the offset profile, which accounts for the electricity required to restore a suitable BESS state-of-charge (SOC) and achieve a suitable level of flexibility along the day of operation.…”

“…The control problem consists in a model predictive control strategy actuated with 10 sec resolution which determines the BESS charge/discharge current in order to minimize the mismatch between the 5-minute average active power flow realization and the dispatch plan, while obeying to BESS operational constraints (i.e., BESS current, voltage and state-of-charge should be in their respective range). The control problem formulation, which is omitted here for a reason of space, is according to what proposed and experimentally validated in [6].…”