Computer-Aided Modeling and Analysis of Power Processing Systems (CAMAPPS), phase 1

The large-signal behaviors of a regulator depend largely on the type of power circuit topology and control. Thus, for maximum flexibility, it is best to develop models for each functional block a independent modules. A regulator can then be configured by collecting appropriate pre-defined modules for each functional block. In order to complete the component model generation for a comprehensive spacecraft power system, the following modules were developed: solar array switching unit and control; shunt regulators; and battery discharger. The capability of each module is demonstrated using a simplified Direct Energy Transfer (DET) system. Large-signal behaviors of solar array power systems were analyzed. Stability of the solar array system operating points with a nonlinear load is analyzed. The state-plane analysis illustrates trajectories of the system operating point under various conditions. Stability and transient responses of the system operating near the solar array's maximum power point are also analyzed. The solar array system mode of operation is described using the DET spacecraft power system. The DET system is simulated for various operating conditions. Transfer of the software program CAMAPPS (Computer Aided Modeling and Analysis of Power Processing Systems) to NASA/GSFC (Goddard Space Flight Center) was accomplished

Active and hybrid filters in medium voltage distribution power systems

This paper presents the design of different topologies of active power filters to compensate reactive power and harmonics in the medium voltage level of a distribution power system. One pure active filter and two hybrid topologies, are implemented. A pure active compensation is obtained with a Shunt Active Power Filter (SAPF). The shunt combination of SAPF and passive filter, form one of the hybrid topologies implemented, named Shunt Hybrid Active Power Filter (SHAPF). The other hybrid topology, called Hybrid Shunt Active Power Filter (HSAPF), connects the active filter in series with two shunt passive filters. The control algorithm are implemented with the d-q theory measuring the system current to compensate the load, setting a feedback control loop, rather than a simple feedforward compensation. Simulation for different load demands and distortions are performed. Finally a comparative evaluation of the different filters is carried out.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE

Design and implementation of a single phase active power filter

Various active filter solutions have been proposed in recent years {I], {2], and are still being widely investigated today. This thesis discusses the design and implementation of the shunt AP F topology

An Update on Power Quality

Power quality is an important measure of fitness of electricity networks. With increasing renewable energy generations and usage of power electronics converters, it is important to investigate how these developments will have an impact to existing and future electricity networks. This book hence provides readers with an update of power quality issues in all sections of the network, namely, generation, transmission, distribution and end user, and discusses some practical solutions

Improvement of resonant harmonic filter effectiveness in the presence of distribution voltage distortion

Resonant harmonic filters (RHFs), are the most common devices installed in distribution systems for reducing distortion caused by harmonic generating loads. When such filters are applied in systems with a distorted distribution voltage their effectiveness may decline drastically. This dissertation explores the causes of degradation of RHFs effectiveness and suggests methods of their improvement both by optimization algorithms and by modification of the filter structure. An optimization based design method is developed for the conventional RHF. It takes into consideration the interaction of the filter with the distribution system and provides a filter which gives the maximum effectiveness with respect to harmonic suppression. The results for the optimized filters, applied in some typical cases, are given, and the limits of effectiveness for a common application are explored. For cases where the conventional RHF cannot be applied due to low effectiveness, a resonant harmonic suppressor, referred to as a RHF with line inductor, is investigated. It is formed by the addition of a line inductor to a conventional RHF, and it has a higher effectiveness in the presence distribution voltage distortion. A similar method of optimization based design is developed and evaluated for the RHF with line inductor as for the conventional RHF. Also, the limits of its effectiveness are explored. One major disadvantage of the RHF with line inductor is the load voltage reduction due to the additional impedance between the distribution system and load. For loads with variable reactive power, the voltage drop across the line inductor may reach an unacceptable level. Also, the fluctuation of the load voltage could increase. In order to reduce these effects, an adaptive capability with respect to load reactive power compensation is added to the filter. Such a filter, referred to as a semi-adaptive RHF, is obtained when a RHF is combined with a thyristor switched inductor (TSI). The addition of the TSI also increases flexibility in the design of the filter with respect to the line inductor’s value. Design aspects of the semi-adaptive RHF are explored and simulation results are presented

Power quality improvement by using photovoltaic based shunt active harmonic filter with Z-source inverter converter

Introduction. The major source of energy for a long time has been fossil fuels, however this has its drawbacks because of their scarcity, exhaustibility, and impossibility of reusing them. Presently, a shunt active harmonic filter-equipped two-stage solar photovoltaic system is showing off its performance shunt active harmonic filter. The global power system has been impacted by current harmonics during the most modern industrial revolution. Novelty. The proposed work is innovative, by adopting the hysteresis modulation mode with Z-source inverter to enhance the performance of the system. Furthermore, the shunt active harmonic filter also get assists in this system for better improvement in the quality of power. Purpose. By incorporating an impedance source inverter and a photovoltaic shunt active harmonic filter methods, harmonic issues are mitigated. Methods. Load compensation is one of the services that the shunt active harmonic filter offers, in addition to harmonic compensation, power factor correction, and many other functions. The current pulse width modulation voltage source inverter method is more expensive, requires two converters owing to its two-stage conversion, has significant switching losses, and has a low rate of the reaction. The new model, in which the voltage source inverter is substituted out for a Z-source inverter converter, has been developed in order to address the problems of the existing system. Results. Rather than using a hybrid of DC-DC and DC-AC converters, the suggested system uses a shunt active harmonic filter that is powered by a photovoltaic source using a Z-source inverter. Utilizing Z-source inverter helps to address the present issues with conventional configurations. Practical value. By using software MATLAB/Simulink, this photovoltaic shunt active harmonic filter technique is analyzed. Shunt active harmonic filter, which produces compensatory current from the reference current obtained as from main supply, is powered by the photovoltaic array.Вступ. Основним джерелом енергії довгий час були викопні види палива, проте це мало свої недоліки через їх дефіцит, вичерпність та неможливість їх повторного використання. В даний час двоступенева сонячна фотоелектрична система, обладнана активним шунтуючим фільтром гармонік, демонструє свої робочі характеристики шунтуючого активного фільтра гармонік. На глобальну енергетичну систему вплинули гармоніки струму під час найсучаснішої промислової революції. Новизна. Пропонована робота є інноваційною, оскільки вона використовує режим гістерезисної модуляції з інвертором Z-джерела для підвищення продуктивності системи. Крім того, шунтуючий активний фільтр гармонік також допомагає в цій системі для покращення якості електроенергії. Мета. Включення інвертора джерела імпедансу та методів активного фільтру гармонік із фотогальванічним шунтом знижує гармонійні проблеми. Методи. Компенсація навантаження – це одна з функцій, які шунтуючий активний фільтр гармонік пропонує на додаток до компенсації гармонік, корекції коефіцієнта потужності та багатьох інших функцій. Інверторний метод широтно-імпульсної модуляції струму дорожчий, вимагає двох перетворювачів через його двокаскадного перетворення, має значні втрати комутації і має низьку швидкість реакції. Нова модель, в якій інвертор джерела напруги замінює перетворювач інвертора Z-джерела, була розроблена для вирішення проблем існуючої системи. Результати. Замість використання гібрида перетворювачів постійного та змінного струму в запропонованій системі використовується активний шунтуючий фільтр гармонік, який живиться від фотоелектричного джерела з використанням інвертора Z-джерела. Використання інвертора з Z-джерелом допомагає вирішити проблеми з традиційними конфігураціями. Практична цінність. За допомогою програмного забезпечення MATLAB/Simulink аналізується метод активного фільтру гармонік фотоелектричного шунта. Шунтуючий активний фільтр придушення гармонік, який виробляє компенсаційний струм із опорного струму, отриманого від мережі, живиться від фотоелектричної батареї

Odd-Harmonic Digital Repetitive Control of a Single-Phase Current Active Filter

Shunt active power filters have been proved as useful elements to correct distorted currents caused by nonlinear loads in power distribution systems. This work presents an all-digital approach, based on the repetitive control technique, for their control. In particular, a special digital repetitive plug-in controller for odd-harmonic discrete-time periodic references and disturbances is used. This approach does not introduce high gain at those frequencies for which it is not needed, and thus it improves robustness. Additionally, the necessary data memory capacity is lower than in traditional repetitive controllers. The design is performed for the particular case of single-phase shunt active filter with a full-bridge boost topology. Several experimental results are also presented to show the good behavior of the closed-loop system.Peer Reviewe

New hybrid active power filter for harmonic current suppression and reactive power compensation

In the case of undistorted and balanced grid voltages, low ratio shunt Active Power Filters (APFs) can give unity power factors and achieve current harmonic cancellation. However, this is not possible when source voltages are distorted and unbalanced. In this study, the cost-effective hybrid active power filter (HAPF) topology for satisfying the requirements of harmonic-current suppression and non-active power compensation for industry is presented. An effective strategy is developed to observe the effect of the placement of power capacitors and LC filters with the shunt active power filter. A new method for alleviating the negative effects of a non-ideal grid voltage is proposed that uses a self-tuning filter algorithm with instantaneous reactive power theory. The real-time control of the studied system was achieved with a field programmable gate array (FPGA) architecture, which was developed using the OPAL-RT system. The performance results of the proposed HAPF system is tested and presented under non-ideal supply voltage conditions