Reduced and aggregated distribution grid representations approximated by polyhedral sets

Direct Current (DC) grids are considered an attractive option for integrating high shares of renewable energy sources in the electrical distribution grid. Hence, in the future, Alternating Current (AC) and DC systems could be interconnected to form hybrid AC-DC distribution grids. This paper presents a two-step state estimation formulation for the monitoring of hybrid AC-DC grids. In the first step, state estimation is executed independently for the AC and DC areas of the distribution system. The second step refines the estimation results by exchanging boundary quantities at the AC-DC converters. To this purpose, the modulation index and phase angle control of the AC-DC converters are integrated into the second step of the proposed state estimation formulation. This allows providing additional inputs to the state estimation algorithm, which eventually leads to improve the accuracy of the state estimation results. Simulations on a sample AC-DC distribution grid are performed to highlight the benefits resulting from the integration of these converter control parameters for the estimation of both the AC and DC grid quantities.

Download Full-text

Enhancing Distribution Grid Resilience Through Model Predictive Controller Enabled Prioritized Load Restoration Strategy

2020 52nd North American Power Symposium (NAPS) ◽

10.1109/naps50074.2021.9449732 ◽

2021 ◽

Author(s):

Abinet Tesfaye Eseye ◽

Xiangyu Zhang ◽

Bernard Knueven ◽

Wesley Jones

Keyword(s):

Distribution Grid ◽

Model Predictive Controller ◽

Predictive Controller

Download Full-text

Prosumers’ Behavior under a Regulation That Encourages Strict Self-Sufficiency. The Case of Spanish Photovoltaic Micro-Generation

Energies ◽

10.3390/en14041114 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1114

Author(s):

Pere Mir-Artigues ◽

Pablo del Río

Keyword(s):

Electricity Markets ◽

Electricity Market ◽

Specific Form ◽

Economic Behavior ◽

Distribution Grid ◽

Self Sufficiency ◽

Regulatory Limits ◽

Regulatory Measures ◽

Self Production ◽

Municipal Level

The reduction of equipment costs encourages the diffusion of photovoltaic micro-generation, however, proper regulatory measures should be implemented to facilitate self-production dissemination and to promote the emergence of new electricity markets which integrate prosumers. The specific form of these markets will depend on the level of prosumers’ self-sufficiency and the type of grid to which they will be connected. Unfortunately, Spain has been an example of resistance to micro-generation deployment. However, some things have started to change recently, albeit only to a certain extent. This article explains the key elements of the latest regulation of photovoltaic micro-generation in Spain and, through a stylized model, describes the economic behavior of prosumers in such a regulatory framework. It is concluded that this regulation only encourages prosumer plants which are strictly focused on self-sufficiency because it discourages exports and limits capacities and this regulation discourages the smart renewal of the distribution grid because it prevents prosumers from participating in the electricity market. It is recommended that the aforementioned regulatory limits be removed and pilot experiences for the market participation of prosumers be promoted by creating the appropriate technical and regulatory conditions, for example, at the municipal level.

Download Full-text

Power Hardware-in-the-Loop: Response of Power Components in Real-Time Grid Simulation Environment

Energies ◽

10.3390/en14030593 ◽

2021 ◽

Vol 14 (3) ◽

pp. 593

Author(s):

Moiz Muhammad ◽

Holger Behrends ◽

Stefan Geißendörfer ◽

Karsten von Maydell ◽

Carsten Agert

Keyword(s):

Real Time ◽

Power Distribution ◽

Control Strategies ◽

Power Grid ◽

Energy System ◽

Hardware In The Loop ◽

Distribution Grid ◽

Compensation Strategy ◽

Software Environment ◽

The Real

With increasing changes in the contemporary energy system, it becomes essential to test the autonomous control strategies for distributed energy resources in a controlled environment to investigate power grid stability. Power hardware-in-the-loop (PHIL) concept is an efficient approach for such evaluations in which a virtually simulated power grid is interfaced to a real hardware device. This strongly coupled software-hardware system introduces obstacles that need attention for smooth operation of the laboratory setup to validate robust control algorithms for decentralized grids. This paper presents a novel methodology and its implementation to develop a test-bench for a real-time PHIL simulation of a typical power distribution grid to study the dynamic behavior of the real power components in connection with the simulated grid. The application of hybrid simulation in a single software environment is realized to model the power grid which obviates the need to simulate the complete grid with a lower discretized sample-time. As an outcome, an environment is established interconnecting the virtual model to the real-world devices. The inaccuracies linked to the power components are examined at length and consequently a suitable compensation strategy is devised to improve the performance of the hardware under test (HUT). Finally, the compensation strategy is also validated through a simulation scenario.

Download Full-text

Improving PV Resilience by Dynamic Reconfiguration in Distribution Grids: Problem Complexity and Computation Requirements

Energies ◽

10.3390/en14040830 ◽

2021 ◽

Vol 14 (4) ◽

pp. 830

Author(s):

Filipe F. C. Silva ◽

Pedro M. S. Carvalho ◽

Luís A. F. M. Ferreira

Keyword(s):

Distributed Generation ◽

Optimal Solution ◽

Dynamic Reconfiguration ◽

Scheduling Problem ◽

Low Carbon ◽

Distribution Grid ◽

Medium Voltage ◽

Classical Computing ◽

The Impact ◽

Distribution Grids

The dissemination of low-carbon technologies, such as urban photovoltaic distributed generation, imposes new challenges to the operation of distribution grids. Distributed generation may introduce significant net-load asymmetries between feeders in the course of the day, resulting in higher losses. The dynamic reconfiguration of the grid could mitigate daily losses and be used to minimize or defer the need for network reinforcement. Yet, dynamic reconfiguration has to be carried out in near real-time in order to make use of the most updated load and generation forecast, this way maximizing operational benefits. Given the need to quickly find and update reconfiguration decisions, the computational complexity of the underlying optimal scheduling problem is studied in this paper. The problem is formulated and the impact of sub-optimal solutions is illustrated using a real medium-voltage distribution grid operated under a heavy generation scenario. The complexity of the scheduling problem is discussed to conclude that its optimal solution is infeasible in practical terms if relying upon classical computing. Quantum computing is finally proposed as a way to handle this kind of problem in the future.

Download Full-text