Distribution network topology identification (DNTI) is an important prerequisite for distribution system operation. Frequent topology changes and limited measurement equipment make identifying the correct topology una...
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Distribution network topology identification (DNTI) is an important prerequisite for distribution system operation. Frequent topology changes and limited measurement equipment make identifying the correct topology unavoidably challenging. To this end, this paper proposes a state estimation method for distribution network topology identification using a small amount of phasor measurement unit (PMU) measurement data. Firstly, this paper introduces the application of the structural equation model (SEM) in distribution networks and explains the relationship between branch currents and topology. Then, auxiliary variables are introduced for the feasible domain problem present in the algorithm, which improves the solvability of the algorithm. In addition, this paper reconsiders the operation mode constraints in terms of nodes from the perspective of distribution network operation mode. The Structural Equation Modeling-based mixedintegerprogramming (SEM-MIP) method proposed in this paper can be solved using existing commercial solvers, and its effectiveness has been verified by simulation in IEEE 33-node test system and IEEE 123-node test system.
Comprehensively considering the operation cost and safety constraints of nuclear power, an optimal operation scheme of large-scale nuclear power plant participating in peak load regulation of power system is proposed....
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Comprehensively considering the operation cost and safety constraints of nuclear power, an optimal operation scheme of large-scale nuclear power plant participating in peak load regulation of power system is proposed. After quantitatively analysing the peak load regulation cost of nuclear power, the optimal objective is set to minimise the total operation cost including the fuel cost, the start-stop cost, and the peak load regulation cost. On the basis of the normal constraints of power scheduling, safety constraints of the nuclear power unit's daily output performance and power characteristic constraints of the pumped storage unit are considered. The mixed integer programming method is used to achieve the solution of the optimal operation scheme. Simulation results from a regional power system show that the proposed optimal operation scheme can effectively reflect the real characteristic of nuclear power and apply to power dispatching analysis under the background of the large-scale access of nuclear power. In comparison to other two typical schemes of peak load regulation, the proposed optimal operation scheme of peak load regulation is more economic and efficient.
Femto cells a.k.a. Low Power Nodes (LPNs) are used to improve indoor data rates as well as to reduce traffic load on macro Base Stations (BSs) in LTE cellular networks. These LPNs are deployed inside office buildings ...
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ISBN:
(纸本)9781479935123
Femto cells a.k.a. Low Power Nodes (LPNs) are used to improve indoor data rates as well as to reduce traffic load on macro Base Stations (BSs) in LTE cellular networks. These LPNs are deployed inside office buildings and residential apartment complexes to provide high data rates to indoor Users. With high SINR (Signal- to- Interference plus Noise Ratio) the users experience good throughput, but the SINR decreases significantly because of interference and obstacles such as building walls, present in the communication path. So, efficient placement of Femtos in buildings while considering Macro- Femto interference is very crucial for attaining desirable SINR. At the same time, minimizing the power leakage in order to improve the signal strength of outdoor users in a high interference (HIZone) around the building area is important. In our work, we have considered obstacles (walls, floors) and interference between Macro and Femto BSs. To be fair to both indoor and outdoor users, we designed an efficient placement and power control SON (Self organizing Network) algorithm which optimally places Femtos and dynamically adjusts the transmission power of Femtos based on the occupancy of Macro users in the HIZone. To do this, we solve two mixedintegerprogramming (MIP) methods namely: Minimize number of Femtos (MinNF) method which guarantees threshold SINR (S INRTh) - 2dB for all indoor users and optimal Femto power (OptFP) allocation method which guarantees S INRTh (- 4 dB) for indoor users with the Macro users SINR degradation as lesser than 2dB.
Programmable Logic Controllers (PLCs) are widely used in industry. In PLC-based control systems, low-resolution (especially ON-/OFF) sensors are inexpensive, and actuators are commonly used because they are compatible...
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Programmable Logic Controllers (PLCs) are widely used in industry. In PLC-based control systems, low-resolution (especially ON-/OFF) sensors are inexpensive, and actuators are commonly used because they are compatible with programming languages used in PLCs. PLC switches the actuators ON/OFF as the state of the sensor changes between ON/OFF In designing PLC-based systems, the design of the parameters of these sensors and actuators (e.g., position of limit switches and torque of motors) is an important problem because they affect the overall performance of the system. This problem, however, has not yet been fully discussed. In the present paper, a systematic design method for this problem is developed. The main concept is to express the model of the system as a mixed Logical Dynamical System (MLDS) and to formulate the problem as a mathematical programming problem. The developed idea is applied to the line-following control of a two-wheeled vehicle. The usefulness of the proposed method is demonstrated through simulation and experiments. (c) 2007 Wiley Periodicals, Inc.
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