Two-leg three-phase inverter control for STATCOM and SSSC applications

Flexible ac transmission systems (FACTS) devices are attracting an increasing interest both in power system academic research and in electric utilities for their capabilities to improve steady-state performance as well as system stability. Several converter topologies for FACTS applications have been proposed in the recent literature, even if those based upon voltage source inverters (VSI) seem to be more attractive due to their intrinsic capability to rapidly respond to network changes such as perturbations subsequent to a fault and their property of being immune to resonance problem. In this paper, a new topology for inverter-based FACTS is proposed. This configuration, employing a two-leg three-phase inverter is employed for both series and parallel-connected reactive power compensators. The converter utilizes a modular topology for allowing a satisfaction of electronic components rating. A control strategy based on variable structure control technique with sliding mode is employed to track appropriate reference quantities. Design and control, as well as good tracking performances, are also verified through numerical simulations

Power quality improvements through power electronic interfaced distributed generation

In low-voltage distribution networks a large amount of single-phase nonlinear loads are connected. This leads to the combined presence of power system unbalance and harmonic distortion. The research presented in this paper focusses on these steady-state power quality problems. It uses a harmonic load flow program, implemented in symmetrical components, to investigate the influence of several single-phase inverter control strategies used to connect any kind of primary energy source to the grid. The influence of these single-phase distributed generation units in the three-phase four-wire distribution network is discussed by means of two recently formulated indicators that combine the power system unbalance and the existing harmonics

Penghasilan modul pembelajaran kendiri bahan dan binaan berasaskan web

Perkembangan teknologi maklumat dalam dunia pendidikan tidak Iagi boleh dinafikan pada masa kini. Keperluan yang meningkat dalam sistem pembelajaran dan pengajaran memerlukan mereka yang terlibat memberi sepenuh tumpuan terhadap mata pelajaran bagi mencapai matlamat, untuk tujuan ini modul pembelajaran kendiri di hasilkan bagi membantu memudahkan pelajar dan pensyarah dalam mata pelajaran Bahan dan Binaan agar dapat mengikuti pelajaran tersebut secara berkesan tanpa membuang masa. Seramai 35 orang pelajar diploma kejuruteraan Awam Politeknik Sultan Abdul Halim Muadzam Shah , Jitra Kedah terlibat sebagai responden. Statistik deskriptif digunakan dalam mengumpul dan menganalisis data. Secara keseluruhannya dari hasil kajian, menunjukkan para pelajar memberikan maklum balas yang positif terhadap modul pembelajaran kendiri Bahan dan Binaan berasaskan web ini. Dari hasil kajian ini juga didapati bahawa kebanyakan pelajar lebih berminat terhadap menggunakan media yang pelbagai seperti teks, audio dan visual. Walau bagaimana pun masih terdapat beberapa aspek yang perlu diperbaiki untuk memantapkan modul pembelajaran kendiri ini. Bagi menyokong perkembangan dan penggunaan teknologi maklumat dalam pendidikan keijasama daripada pelbagai pihak seperti Kementerian dan Politeknik sendiri diperlukan terutama dari segi kemudahan komputer, kursus penggunaan perisian dan sebagainya.ini adalah penting bagi melahirkan graduan yang berkualiti dan mempunyai pengetahuan yang meluas dalam bidang teknologi pada masa akan datang

Modelling and control of a variable-speed switched reluctance generator based wind turbine

This paper studies the system modelling and control aspects of switched reluctance generator (SRG) based variable speed wind turbines. A control system is implemented to provide proper operation of the SRG as well as power tracking capabilities for varying wind speeds. The control system for the grid side inverter that will allow the SRG to properly generate power to the system is also presented. Studies are presented of both the SRG and inverter control systems capabilities during a balanced three-phase fault. The paper will demonstrate that the SRG based wind turbine presents a feasible variable wind speed solution with good fault response capabilities

A Generalized Voltage Control Algorithm for Smooth Transition Operation of Microgrids

The chapter proposes a generalized control algorithm that can reject the disturbances associated with microgrid transition operation to facilitate smooth microgrid transition operation. Firstly, the literature review of the state-of-the-art gives a deep analysis of the disturbances associated with microgrid transition operation and it reveals that the same controller should be adopted in the inverter control layer to prevent some harmful transients during transition. Then, a generalized voltage control algorithm in inverter control layer that can achieve smooth transition of microgrid is developed including the formulation of the problem, description of the design methodology and design procedures, and analytical study. The salient feature of the developed generalized voltage control algorithm is that the disturbances associated with microgrid transition are fully cancelled by using inverse dynamic model, and the inverter control layer can be seen as a bypass for the application layer. The practical feasibility of the proposed control algorithm is demonstrated by implementing and testing in a signal level hardware-in-the-loop (HIL) platform

Virtual Impedance Impact on Inverter Control Topologies

The different nature of the energy resources requires high reliable power inverters to supply regulated power to the end customer and to ease its integration within the microgrid. In this paper, modeling, design and control of inverters are presented for two different topologies. The study addresses the feasibility of the single loop and double loop control of inverters. The bode plot technique is used to analyze the system behavior when the inductor and the capacitor currents are used as feedback signals. The different output impedance natures affect the power sharing between inverters and stability. Therefore, a proposed virtual impedance is implemented to enhance the control performance. Simulation results are presented to show the validity of the control strategy

Solar Power Station Output Inverter Control Design

The photovoltaic applications spreads in these days fast, therefore they also undergo great development. Because the amount of the energy obtained from the panel depends on the surrounding conditions, as intensity of the sun exposure or the temperature of the solar array, the converter must be connected to the panel output. The Solar system equipped with inverter can supply small loads like notebooks, mobile chargers etc. in the places where the supplying network is not present. Or the system can be used as a generator and it shall deliver energy to the supply network. Each type of the application has different requirements on the converter and its control algorithm. But for all of them the one thing is common – the maximal efficiency. The paper focuses on design and simulation of the low power inverter that acts as output part of the whole converter. In the paper the design of the control algorithm of the inverter for both types of inverter application – for islanding mode and for operation on the supply grid – is discussed. Attention is also paid to the design of the output filter that should reduce negative side effects of the converter on the supply network