Search results for "landed"
showing 10 items of 15 documents
Józef Wacław Dąbrowski (1797–1862). Wołynianin w armii Królestwa Polskiego
2021
W artykule, w oparciu o nieznane i tym samym niewykorzystywane dotąd przez historyków wspomnienia, przedstawione zostały dzieciństwo i młodość Józefa Wacława Dąbrowskiego, oficera wojska Królestwa Polskiego, dowódcę w randze kapitana i majora oddziałów powstańczych jesienią 1830 – latem 1831 r. Koleje jego losów i kariera wojskowa są tak typowe, jak i odbiegające od znanych i omawianych w literaturze przedmiotu schematów. Typowe, gdyż dzięki wywodzeniu się z kręgów średnio zamożnego ziemiaństwa rozpoczął służbę wojskową od stopnia kadeta, aby przed upływem roku awansować na podchorążego i uzyskać skierowanie do szkoły podchorążych, stanowiącej niezbędny etap służby potrzebny do awansu ofice…
Vidzemes Lielais Zviedru Kadastrs kā saimniecības vēstures avots
1942
Kadastrs - sistematizēti kādu zemes vai ūdens nogabalu vai citu objektu dati; ar nodokļiem apliekamo zemju saraksts un novērtējums pilsētās un laukos. Zemes kadastru sāka ar zemes uzmērīšanu un vērtēšanu, vienlaikus veicot muižu redukciju, atsavinot lielāko daļu muižas zemju, kuras nodeva Zviedrijas valsts pārziņā. Tas bija labi izstrādāts kadastrs, un to izmantoja no 1691. līdz 1911. gadam, t. i., 220 gadus. Tas pasaulē ir samērā mazpazīstams, un tagadējās Latvijas un Igaunijas teritorijā tam bija tikai lokāla nozīme. Muižu redukcija .17. gs. 2. pusē, pieaugot absolūtisma tendencēm Eiropā, Zviedrijas karalis Kārlis XI (Karl XI) centās nostiprināt varu visā valstī. Viens no pasākumiem bija …
Multi-objective optimized management of electrical energy storage systems in an islanded network with renewable energy sources under different design…
2014
The subject addressed in this paper is the definition of some strategies for the design and the optimaized management of EES (Electrical Energy Storage) systems, for an existing islanded distribution network supplying the Island of Pantelleria (Italy) in the Mediterranean Sea. In the paper the authors have drawn interesting conclusions through the application of an efficient MO (multi-objective) optimization algorithm, the NSGA-II, minimizing the energy losses in the grid, the total electricity generation cost and the greenhouse gas emissions. The results obtained for different installation scenarios of the EES are presented and discussed, putting into evidence the technical, environmental …
Nonlinear droop control for minimum power losses operation in islanded microgrids
2017
In this work, a modified primary regulation technique is proposed to control one of the inverter interfaced units feeding an islanded microgrid. The proposed approach employs an off-line minimum losses Optimal Power Flow, OPF, to extract a lookup table for the composition of the droop curve. Simulations prove that generators reach an operating point that corresponds to a minimum loss operation for the relevant power flow distribution. Since OPF has been implemented with frequency and voltage dependent models, the results of the modified droop are stable and also energy efficient. Further studies will address further analysis on systems showing different R/X ratio and modeling of more genera…
A parametric study on unbalanced three phase islanded microgrids with inverter interfaced units
2013
In this paper, the solution of the power flow for unbalanced three phase microgrids systems is proposed. The study aims at the integration of inverter interfaced units using the control law used for primary voltage and frequency regulation, so as to take into account possible small variations of these parameters to account for sudden load changes. The proposed study deals with unbalanced systems which is the typical case of small distribution systems and shows how the power losses term varies as the regulators parameters vary as well, thus showing that these are sensitive parameters that could have an important role in optimal management of such systems.
Optimal power flow based on glow worm-swarm optimization for three-phase islanded microgrids
2014
This paper presents an application of the Glowworm Swarm Optimization method (GSO) to solve the optimal power flow problem in three-phase islanded microgrids equipped with power electronics dc-ac inverter interfaced distributed generation units. In this system, the power injected by the distributed generation units and the droop control parameters are considered as variables to be adjusted by a superior level control. Two case studies with different optimized parameters have been carried out on a 6-bus test system. The obtained results showed the effectiveness of the proposed approach and overcomes the problem of OPF in islanded microgrids showing loads unbalance.
La géopolitique du foncier : pouvoirs et échelles d’action
2018
When it comes to land management, successive reforms to territorial governancehave resulted in power games that have placed intercommunalauthorities in charge of coordination without any clearly defined institutionalhierarchy. The interviews conducted with actors in the territories studied(the Communauté de communes [joint local authorities] of the Vallée deChamonix Mont-Blanc, Pays du Grésivaudan and Massif du Vercors) and ouranalysis of the public policy tools they use highlight the change in scale thathas occurred in land management. We argue that the geopolitical stakes ofland have been elucidated with the constitution of dedicated engineering,which invites us to distinguish between the…
Frequency constrained optimal Power Flow based on Glow-worm Swarm Optimization in Islanded Microgrids
2015
This work presents an application of a swarm optimization method to solve the optimal power flow problem taking into account the constraints of frequency and line ampacity in three-phase islanded Microgrids. Each generation unit is equipped with a Power Electronics Interface. In the considered formulation, the droop control parameters are considered as variables to be adjusted by a higher control level, while the frequency is kept in rated bounds. Another typical constraint for OPF formulation, the max ampacity of each line, is also considered. Two case studies with different dimensions and electrical features have been considered and the obtained results show the efficiency of the proposed…
Optimal Power Flow in three-phase islanded microgrids with inverter interfaced units
2015
In this paper, the solution of the Optimal Power Flow (OPF) problem for three phase islanded microgrids is studied, the OPF being one of the core functions of the tertiary regulation level for an AC islanded microgrid with a hierarchical control architecture. The study also aims at evaluating the contextual adjustment of the droop parameters used for primary voltage and frequency regulation of inverter interfaced units. The work proposes a mathematical method for the OPF solution also considering the droop parameters as variables. The output of the OPF provides an iso-frequential operating point for all the generation units and a set of droop parameters for primary regulation. In this way, …
OPTIMAL POWER FLOW IN ISLANDED MICROGRIDS
In this thesis, studies about OPF in islanded MGs have been carried out. First, an original formulation and solution approach for the OPF problem in islanded distribution systems is proposed. The methodology is well suited for AC microgrids and can be envisioned as a new hierarchical control structure comprising only two levels: primary and tertiary regulation, the latter also providing iso-frequency operating points for all units and optimized droop parameters for primary regulation. The OPF provides a minimum losses operating point for which voltage drops are limited and power sharing is carried out according to the most adequate physical properties of the infrastructure thus giving rise …