IMPROVING ENERGY EFFICIENCY IN BUILDINGS USING MICROGRIDS

Modern society has a growing need for the electricity. To protect the environment, future energy demand must be met with more environmentally friendly technologies, such as renewable energy sources. Because of its vast availability, solar radiation has been used for decades to generate electricity through photovoltaic systems (PV) for residential, educational, and commercial buildings. However, the growth of distributed generation (and renewable energy sources) across power systems in industrialized countries has created new challenges. Random renewable generation causes an imbalance between electricity production and consumption, so smart grids and microgrids may be solutions. In this article, we investigate improving the energy efficiency in the Faculty of Electrical Engineering building in Osijek by using a microgrid. To do so, we compared the total electricity consumption of the building and the production of a 10 kWp photovoltaic power plant on that building. The improvement in energy efficiency of the building produced a maximum savings of up to 10% of the building’s total electricity consumption

Demand Side Management inside a Smart House

The upgraded traditional grid, also known as the smart grid, that incorporates information and communications technologies will change not only electricity production but also consumption. In combination with Photovoltaics (PV) and electrical storage, demand side management (DSM) is a promising solution for net-zero energy building (NZEB). NZEB will be able to produce energy for its own needs and also feed a surplus back to the grid. In scientific papers, it has already been proven that the use of electrical energy storage can improve the power quality and store variable production of renewable energy. Smart meters are a step forward because they enable a two-way communication between a customer and a utility. In this way, it will be possible to monitor consumption and electricity prices on the market in real time. Furthermore, this will enable the consumer to turn off devices that are large loads, or let the DSM system known as load management do its job such to reduce energy consumption in a given period. DSM will automatically switch off a big load in a manner that does not disturb user comfort. Smart appliances at the end-user level such as the Internet protocol (IP) addressable appliance controlled by external signals from the utility or end-user will enable load shifting to off-peak periods. Solar radiation is prevalent everywhere and can be used to generate electricity at the point of consumption, thereby reducing the losses in transmission. Only one hour of solar radiation is sufficient to cover the annual consumption; this shows that the future of low-carbon energy production lies in the use of solar radiation

Review of Non-Traditional Optimization Methods for Allocation of Distributed Generation and Energy Storage in Distribution System

The integration of distributed energy sources transforms passive distributed grid, in which the energy flows only in one direction (from the source to the consumer), in an active one, in which energy flows in both directions. To maximize positive impacts, which distributed generation (DG) can provide to the distribution network, it is necessary to determine the optimal allocation of distributed generation. The optimal allocation can be determined by using the optimization method. There are two main categories: exact methods (traditional) and heuristic (non-traditional) methods. Exact methods search for global optimum while heuristic methods achieve satisfactory solutions with greater computation speed. This paper gives a brief review of non-traditional methods used for determining optimal location and optimal power of DG with the aim to reduce real power losses and to improve voltage characteristics. Also, there is a review of the application of those methods in determining the optimal power, optimal location and optimal cycle of charging/discharging of electrical energy storage systems

IMPROVED METAHEURISTIC METHOD FOR THE OPTIMAL ACCOMMODATION OF VOLTAGE DISTANCE DEVICES

U doktorskom radu predstavljen je binarni algoritam šišmiša, unaprijeđen s težinskim koeficijentom izloženog područja sabirnica sustava, za određivanje optimalne lokacije i broja mjernih uređaja za mjerenje naponskih propada. Navedeni algoritam je razvije u Matlabu. Predloženi algoritma koristi matricu područja dosega nadziranja, koja se kreira simulacijama kratkih spojeva u testnom sustavu i na temelju određenog napona praga, pretvara se u binarni oblik. Jednofazni i trofazni kratki spojevi simulirani su u DigSilent softveru na IEEE 39-sabirničkom sustavu, korištenjem međunarodne norme IEC 60909. Klasifikacija voda u kvaru provedena je algoritmom stabla odlučivanja, a mjesto kvara na vodu predviđeno je višestrukom linearnom regresijom. Predloženi unaprijeđeni binarni algoritam šišmiša uspješno je primijenjen za određivanje optimalnog broja i lokacije uređaja za mjerenje naposkih propada na IEEE 39-sabirničkom sustavu za trofazne i jednofazne kratke spojeve.The doctoral thesis presents upgraded binary bat algorithm with a coefficient of the exposed area of the system bus, for determining the optimal location and the optimal number of voltage dip measuring devices. This algorithm is developed in Matlab. The proposed algorithm uses a monitor reach area matrix that is created by the short-circuit simulations in the test system and transformed into a binary matrix based on a given voltage threshold. Single-phase and three-phase short circuits are simulated in DigSilent software on the IEEE 39 bus test system, using International Standard IEC 60909. The classification of the faulted line was carried out by the decision tree algorithm, and the location of the failure on the transmission line was predicted by multiple linear regression. Proposed upgraded binary bat algorithm has been successfully applied for determining optimal allocation and number of voltage dip monitors on IEEE 39 bus test system for three-phase and single-phase short circuits

IMPROVED METAHEURISTIC METHOD FOR THE OPTIMAL ACCOMMODATION OF VOLTAGE DISTANCE DEVICES

U doktorskom radu predstavljen je binarni algoritam šišmiša, unaprijeđen s težinskim koeficijentom izloženog područja sabirnica sustava, za određivanje optimalne lokacije i broja mjernih uređaja za mjerenje naponskih propada. Navedeni algoritam je razvije u Matlabu. Predloženi algoritma koristi matricu područja dosega nadziranja, koja se kreira simulacijama kratkih spojeva u testnom sustavu i na temelju određenog napona praga, pretvara se u binarni oblik. Jednofazni i trofazni kratki spojevi simulirani su u DigSilent softveru na IEEE 39-sabirničkom sustavu, korištenjem međunarodne norme IEC 60909. Klasifikacija voda u kvaru provedena je algoritmom stabla odlučivanja, a mjesto kvara na vodu predviđeno je višestrukom linearnom regresijom. Predloženi unaprijeđeni binarni algoritam šišmiša uspješno je primijenjen za određivanje optimalnog broja i lokacije uređaja za mjerenje naposkih propada na IEEE 39-sabirničkom sustavu za trofazne i jednofazne kratke spojeve.The doctoral thesis presents upgraded binary bat algorithm with a coefficient of the exposed area of the system bus, for determining the optimal location and the optimal number of voltage dip measuring devices. This algorithm is developed in Matlab. The proposed algorithm uses a monitor reach area matrix that is created by the short-circuit simulations in the test system and transformed into a binary matrix based on a given voltage threshold. Single-phase and three-phase short circuits are simulated in DigSilent software on the IEEE 39 bus test system, using International Standard IEC 60909. The classification of the faulted line was carried out by the decision tree algorithm, and the location of the failure on the transmission line was predicted by multiple linear regression. Proposed upgraded binary bat algorithm has been successfully applied for determining optimal allocation and number of voltage dip monitors on IEEE 39 bus test system for three-phase and single-phase short circuits

IMPROVED METAHEURISTIC METHOD FOR THE OPTIMAL ACCOMMODATION OF VOLTAGE DISTANCE DEVICES

U doktorskom radu predstavljen je binarni algoritam šišmiša, unaprijeđen s težinskim koeficijentom izloženog područja sabirnica sustava, za određivanje optimalne lokacije i broja mjernih uređaja za mjerenje naponskih propada. Navedeni algoritam je razvije u Matlabu. Predloženi algoritma koristi matricu područja dosega nadziranja, koja se kreira simulacijama kratkih spojeva u testnom sustavu i na temelju određenog napona praga, pretvara se u binarni oblik. Jednofazni i trofazni kratki spojevi simulirani su u DigSilent softveru na IEEE 39-sabirničkom sustavu, korištenjem međunarodne norme IEC 60909. Klasifikacija voda u kvaru provedena je algoritmom stabla odlučivanja, a mjesto kvara na vodu predviđeno je višestrukom linearnom regresijom. Predloženi unaprijeđeni binarni algoritam šišmiša uspješno je primijenjen za određivanje optimalnog broja i lokacije uređaja za mjerenje naposkih propada na IEEE 39-sabirničkom sustavu za trofazne i jednofazne kratke spojeve.The doctoral thesis presents upgraded binary bat algorithm with a coefficient of the exposed area of the system bus, for determining the optimal location and the optimal number of voltage dip measuring devices. This algorithm is developed in Matlab. The proposed algorithm uses a monitor reach area matrix that is created by the short-circuit simulations in the test system and transformed into a binary matrix based on a given voltage threshold. Single-phase and three-phase short circuits are simulated in DigSilent software on the IEEE 39 bus test system, using International Standard IEC 60909. The classification of the faulted line was carried out by the decision tree algorithm, and the location of the failure on the transmission line was predicted by multiple linear regression. Proposed upgraded binary bat algorithm has been successfully applied for determining optimal allocation and number of voltage dip monitors on IEEE 39 bus test system for three-phase and single-phase short circuits

Determining the Optimal Location and Number of Voltage Dip Monitoring Devices Using the Binary Bat Algorithm

Voltage dips represent a significant power quality problem. The main cause of voltage dips and short-term interruptions is an electrical short circuit that occurs in transmission or distribution networks. Faults in the power system are stochastic by nature and the main cause of voltage dips. As faults in the transmission system can affect more customers than faults in the distribution system, to reduce the number of dips, it is not enough to invest in a small part of the transmission or distribution system. Only targeted investment in the whole (or a large part of the) power system will reduce voltage dips. Therefore, monitoring parts of the power system is very important. The ideal solution would be to cover the entire system so that a power quality (PQ) monitor is installed on each bus, but this method is not economically justified. This paper presents an advanced method for determining the optimal location and the optimal number of voltage dip measuring devices. The proposed algorithm uses a monitor reach area matrix created by short-circuit simulations, and the coefficient of the exposed area. Single-phase and three-phase short circuits are simulated in DIgSILENT software on the IEEE 39 bus test system, using international standard IEC 60909. After determining the monitor reach area matrix of all potential monitor positions, the binary bat algorithm with a coefficient of the exposed area of the system bus is used to minimize the proposed objective function, i.e., to determine the optimal location and number of measuring devices. Performance of the binary bat algorithm is compared to the mixed-integer linear programming algorithm solved by using the GNU Linear Programming Kit (GLPK)