<title>Abstract</title> As a large number of power electronic devices and other nonlinear loads are connected to the system, harmonics generated by them cause great harm quality grid. At present, passive filter active mainly used deal with harmonic pollution. Active is widely used, but its main control method for inverter current mode control. However, new energy system shows characteristics inertia insufficient damping. Therefore, grid-forming external synchronous generator has attracted...

The work described herein discusses the application of generalized cross-correlation method to time delay estimation infrasound signal. At present, basic technique is mainly used However, accuracy based on this not high. In order improve accuracy, applied in paper. can be viewed as applying a weighting or window function cross-power spectrum. An improved given and compared with several other proposed processors similar form. result shows that by high performance stable under different...

As an effective approach of reservoir prediction, poststack impedance inversion has been widely used in industry. However, like other inverse problems, is a quintessential ill-conditioned problem. Conventional methods often use regularization techniques such as Tikhonov-type to improve the stability solution. Nevertheless, because this type method constrains process by applying isotropic smoothness impedance, it will result blurred boundaries and micro-geological structures, thereby reducing...

With the continuous decline in cost of distributed photovoltaic systems, systems have met conditions for user-side parity to grid-connected. Its grid-connected capacity and installation penetration rate some areas also continued rise, which has greatly affected safe stable operation distribution network main network. After high is connected, while increasing line loss reducing economy, it raises voltage user's grid connection point, increases neutral current, affects power supply quality...

Magnitude information and direction are utilized to improve the spatiotemporal Kriging method in step of variogram construction. Basement construction is calculate vector distance between time slices, space slices. Criterions discussed, a new model considering both magnitude proposed. Case study using data from National Network Geomagnetic Observatories China carried out for cross validation. Results illustrate that proposed performs better analyzing statistics Mean absolute error (MAE)...

The forecast error characteristic analysis of short-term photovoltaic power generation can provide a reliable reference for system optimal dispatching. In this paper, the total in-day level was stratified by fuzzy C-means algorithm. Then historical PV output data based on numerical characteristics point prediction were classified. A General Gauss Mixed Model proposed to fit distribution various distribution. impact meteorological factors together with taken into full consideration in method....

At present, disc cutters of a full face rock tunnel boring machine are mostly mounted in the traditional way. Practical use engineering projects reveals that this installation method not only heavily affects operation life cutters, but also increases energy consumption machine. To straighten out issue, therefore, rock-breaking model is developed for cutters’ movement after research on breaking forward-slanting cutters. Equations its displacement established based analysis velocity vector...

In the paper measurements to increase calculation accuracy of synchronous generator parameters by using finite element (FE) method are studied in detail at first. Then, through a lot calculations, series curve families 30 MW turbogenerator obtained, including saturation power-angle curve, magnetizing characteristics corresponding different power angles and curves versus some operation conditions. These reflect effects multiple factors cross-magnetization on saturation.

This document researchs on 55kW GSHP black start based 250kW/250kWh battery system and 50kW/10s super capacitor. The modeling methods of asynchronous motor, system, capacitor PCS are given. According to three conditions: direct start, star delta frequency conversion simulates analyses the results. During max AC bus voltage drop reaches 60%, hybrid energy storage is able effectively inhibit inrush current.

Due to weather conditions, the output power of Photovoltaic (PV) systems often experience significant fluctuation. The PV is therefore neither a constant voltage source nor current source. This can lead series issues when connected grid including surge, requirement more spinning reserve capacity and difficulties in participating dispatching. use energy storage could improve quality via controlling output. In this article, Photovoltaic-Energy Storage Hybrid System proposed topology diagram...

By the means of finite element method (FEM), nonlinear characteristic curves and magnetic field distribution a 300 MW turbine generator under normal or abnormal operating condition are obtained, it is found that iron saturation distortion two main factors which cause phenomenon. When power angle given, different exciting currents will result in leakage as affect rotor degree. Thus order to produce certain E <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

In this paper, NSGA-Ⅱ is used to realize the dual-objective optimization and three-objective of solar-thermal photovoltaic hybrid power generation system; Compared with optimal solution set optimization, based on technical economic evaluation indicators belongs category multi-objective optimization. It can be considered that very suitable for system other similar problems.

The feasibility of battery energy storage system (BESS) in ameliorating power transient stability has been proved. However, the required BESS capacity is large, which leads to high price. Meanwhile, improving effect significantly affected by fault location and location. To address problem, a distributed configuration BESS, with coordinated control method, proposed this paper. Firstly, an independent double-closed loop decoupling controller designed for each so that unit can realize...

Leakage permeance of a permanent magnet (PM) is an important factor for improving the accuracy electromagnetic device calculations based on magnetic equivalent circuit (MEC). For PM leakage calculations, traditional simulation method finite element analysis (FEA) and lumped parameter analytical (LPAM) have been considered; it was found that FEA has disadvantage long calculation time LPAM low accuracy. The field lines distribution (MFLD) proposed in this paper order to raise computational...