Distribution System Modeling and Analysis

国際会議報告 IEEE-Power Engineering Society Winter Meeting

https://backend.orbit.dtu.dk/ws/files/165720855/Final_version_for_open_access.pdf

An efficient approach to separate CO2 using supersonic flows for carbon capture and storage

Investigating the entropy generation in condensing steam flow in turbine blades with volumetric heating

Entropy generation and exergy destruction in condensing steam flow through turbine blade with surface roughness

CFD-based shape optimization of steam turbine blade cascade in transonic two phase flows

We propose two novel two-stage Volt/Var control schemes based on the affinely adjustable robust counterpart (AARC) methodology, to mitigate the over-voltage issues caused by integration of photovoltaic panels into distribution systems. To cope with different grid code requirements, our first approach formulates the unused capacity of residential inverters to provide reactive power support based on the real power deviation, while the second approach formulates them based on voltage magnitude deviation. In the first stage of both schemes, we make central measurements throughout the network to determine a linear function, mapping the operating point deviations to the reactive power of inverters. In the second stage, the local controllers use the provided linear functions to determine the required reactive power to keep the voltages within the safe limits. Unlike similar approaches, voltage limit constraints are directly incorporated into the AARC problem, preventing the second stage controllers from unnecessarily use of reactive powers. We compare the performance of our schemes using a Monte-Carlo simulation with four other existing techniques on a real-world 27-bus and the IEEE 906-bus LV feeders. Our simulations show that our approaches decrease the real power loss, reactive power usage, and line congestion compared to the other Volt/Var control schemes.

Affinely Adjustable Robust Volt/Var Control for Distribution Systems With High PV Penetration

Optimal placement and sizing of distributed energy resources (DERs) can be performed from various points of view. In this paper, a multiobjective function is employed to determine optimal place and size of DERs including combination of photovoltaic resources and a small-scale synchronous generator (SSSG) with an internal combustion engine as its prime mover. As the objective function, not only minimization of investment costs, operation costs, and system losses are used, but also the voltage of microgrid (μG) busses and current of lines are considered as constraints. In addition, this paper shows mechanical stresses can be imposed on the SSSG caused by generator swings after short circuit fault clearing. Furthermore, it may lead to mechanical fatigue in its associated shaft and prime mover. Meanwhile, it is revealed that the mechanical stresses depend on the DERs placement and size. Thus, a novel index representing the stresses on the SSSG shaft is applied in the multiobjective goal function. This decreases SSSG loss of life in a μG with overhead lines which has high rate of short circuit faults. Optimization studies are performed in a six-bus and four-DER μG using time-based simulations.

Multiobjective Optimal DERs Placement and Sizing Considering Generator Shaft Fatigue

Active network management through residential owned devices, such as battery systems and smart inverters, has been introduced as a promising solution to mitigate voltage issues caused by rooftop solar. Existing decentralized approaches to determining setpoints for these devices, require network visibility and timed coordination to consider the impact of multiple control actions prescribed simultaneously by different controllers. To address this issue, we propose an online decentralized rulebased control approach, which prevents overvoltage/undervoltage by determining dynamic setpoints of PV smart inverters and battery systems, based on online measured connection point voltage. In the proposed method, successive control actions ensure that the voltage gradually converges to the desired region, and coordination between controllers occurs implicitly via the power system. The effectiveness of the proposed method is assessed on a real 30-bus feeder and achieves results that are within 4% of those obtained by a centralised multi-period AC OPF with perfect forecast.

Active Management of LV Residential Networks under High PV Penetration

In recent years, due to the consumers' need to electricity with the least outages and the highest reliability, power continuity of the electrical systems have been highly regarded by companies in the electrical distribution field. Complexity in the process of distribution automation and manually restoration mechanism in modern distribution networks cause longer duration of outages and make the need to a reliable model for automatic fault location, isolation and service restoration (FLISR) process necessary. In this study, a mathematical model of the FLISR process in a distribution network is presented based on formal methods. The proposed model correctness has been investigated by evaluating its important properties consisting liveness, reachability and deadlock free using UPPAAL tool.

S.M.N.R. Abadi

Papers

CFD-based shape optimization of steam turbine blade cascade in transonic two phase flows

Affinely Adjustable Robust Volt/Var Control for Distribution Systems With High PV Penetration

Multiobjective Optimal DERs Placement and Sizing Considering Generator Shaft Fatigue

Active Management of LV Residential Networks under High PV Penetration

Formal verification of fault location, isolation and service restoration in distribution automation using UPPAAL