Dynamic Simulation and Optimization of an Off-grid Solar Photovoltaic Driven Drinking Fountain with Battery Storage

This paper presents a case study involving the design and energy saving analysis of an off-grid solar photovoltaic driven drinking fountain with battery storage. A dynamic simulation in TRNSYS software is performed to model and evaluate the transient processes occurring in this renewable system. A sensitivity analysis of the main design parameters, power generation capacity and electric storage capacity, was performed in order to optimize the scheme. The case study was carried out at Federal Institute of Education, Science and Technology of Bahia in Salvador, in the northeast of Brazil. The temperature profiles and electrical energy flows of the optimized system are investigated by means of a daily, weekly and yearly analysis. The outcomes achieved show that the optimized system showed a 33.3% increase in thermal efficiency and 15.1 % increase in the global efficiency in relation to the base case. This system was able to produce 5932.7 L of chilled water per year and a 65626.8 Wh reduction of primary energy consumption per year. This study can be applied to universities, schools or places with large flow of people.

An Analytical Approach in Calculation of the inductance of Single-Phase Asynchronous Motors.

In optimizing design of the iron core, it is essential to know the magnetic field of the coil outside the core to get the leakage inductance, because the leakage inductance in this area usually provides high contribution to the flux density in the iron core. In this paper, an analytical solution as an alternative to three-dimensional FEM (finite element method) to calculate the field outside the iron core by solving analytical equation using MathCAD is presented. The analytical method provides results that are close to result given by three-dimensional FEM, but with the great advantage of dramatically reduced computing time.

A Python-Based Interface Design for Electric Power System Education.

Python, which is widely used today, is one of the open-source programming languages. In the Python program, its interface is done through the PyQt5 library. With PyQt5, it is possible to develop object-based software that takes up less space on the disk and runs faster. In this study, an educational calculation and analysis program (ITUPSA) was designed for the Electric power systems course using the Python interface. Electric power systems are one of the fundamental courses in electrical engineering. This main course is taught in three sub-course groups as energy transmission-distribution, energy flow and energy economy. The energy transmission-distribution course package constitutes the first and most comprehensive part of the electric power systems group. In the energy transmission-distribution, the creation of the transmission line model and the calculation of the line parameters form an important part of the training. This section contains very detailed mathematical calculations and it is very important that students get the correct result as a result of these calculations. This can be possible with a lot of practice. The interface design was made by students and faculty to teach practical examples correctly. This developed (ITUPSA) python-based interface program is very suitable for calculation and analysis exercises in both undergraduate and graduate courses in the Electrical Engineering department. The purpose of this study is to create a python-based interface in order to solve the problems related to these lines, to make the types of short, medium and long power transmission lines correct and understandable. In the study, after selecting the type of energy transmission line and all parameters related to the line, the necessary mathematical analysis can be made and also the analysis results can be plotted. The analysis program is available in two languages, English and Turkish.

Small Signal Stability Assessment in Presence of SSSC for a Power System Under Fault Disturbance

The use of FACTS controllers in power grids has resulted in the improvement of stability issues related to the power systems. When the FACTS controllers are used to damp out the power systems oscillation, there series controller inverter like static synchronous series compensator (SSSC) device are the most suitable to resolve the issue. In this paper, importance is given on the optimal operation of the SSSC and to the maintenance of the small signal stability of the system. Here the main focus is to check the system response to stability after the use of SSSC device.

Improvement of Static Voltage Stability of 16-Bus Bali System by Optimal Placement of SVC

In a power system, the reactive power imbalance is related to the stability of the static voltage because the injection of reactive power that the bus receives from the system determines the bus's capability in the system. Rapid increases in real and reactive power losses occur as the system approaches the voltage drop point or the maximum load point. It is necessary to support local and adequate reactive power to avoid system leading to be voltage collapse. This study analyzes the improvement of the margin of static voltage stability using one type of modern control equipment of shunt flexible AC transmission system (FACTS), namely the static var compensator (SVC). The controller's representations are used in the continuation power flow (CPF) process to study static voltage stability. The proposed method's effectiveness has been investigated using a practical test system, namely the Bali 16-bus system, to increase the system loading capacity. The simulation was carried out by installing a modern controller in the best location, namely on bus 07 ASARI; an increase in system margin loading closed to 2% compared to the base case condition, namely λmax = 1,879 p.u with the voltage profile not changing significantly.

Analysis of Under-frequency Load Shedding (UFLS) Relay Setting during Disturbances

Load changes on the system will affect the system stability itself. Load demand that exceeds the generated power will cause the system frequency to decline. Therefore, a load shedding procedure is required to improve the frequency. This research focuses on how to design a load shedding scheme that is activated by the operation of under frequency relay. There are two scenarios to analyze the system performance with a simulation, which are losing power on line about 128 MVA and generator loss power about 192 MVA. Those scenarios result in a decrease in the system frequency to 47.48 Hz and 47.90, respectively. After the load shedding scenario is performed, the frequency became an increase in the range of 51.54 Hz and 49 Hz within a few seconds.

Feasibility of PV Integrated Microgrids in Remote North Canadian Communities.

In this paper a methodology for a transition away from a fossil fuel dependency to clean energy in remote communities in northern Canada is presented. Both technical and non-technical obstacles associated with such a transition to clean energy are outlined. A proposal on how to possibly overcome these obstacles is also presented. The technical aspect of this work includes a case study on one of the communities in northern Manitoba, Canada. The case study is supported by simulations, using the software tool PSCADTM/EMTDCTM. The simulation result illustrates how the control system coordinates various parts of a microgrid and reduces annual diesel consumption.

Techno-Economic Analysis of a Microgrid System To Increase Electricity Access in Rural Areas.

This study analyses the technical and economic performances of a microgrid system which is used to increase the electricity access in a rural area – Hutajulu village, Parmonangan district, North Tapanuli district, Indonesia. There are two types of power distributed generator used in the microgrid system, i.e., diesel generator and solar PV, and there are 20 houses in the village to be supplied electricity by the microgrid system. The results show that the generator would operate 3.754 hours per year and would supply electricity to the houses 2,456 kWh/year during the planning horizon (25 years). The levelized cost of electricity (LCOE) of the diesel generator would be US₵10.7/kWh, and the capacity factor of the diesel generator would be 14%. The average electrical efficiency of the diesel generator is found 27.2%. In case of the solar PV installed in the microgrid system, the operating hour of the solar PV during the planning horizon would be 4,426 hours/year and supplies electricity to the houses 2,153 kWh/year. The levelized cost of electricity of the solar PV would be US₵7.92/kWh.

Implementation of Reactive Power Markets to Enhance the Power System Network.

Reactive power is an important component which plays a critical role in maintaining grid reliability, especially voltage stability. The report presents an analysis of the current compensation strategies followed by different independent system operators (ISOs) in US and identifies the drawbacks in the present compensation schemes. The properties of reactive power which poses an impediment to setup a reactive power market has been compared with the need of a reactive power market. Finally, a possible spot market structure has been considered along with bid formulation and its different components as applicable to different reactive power producing equipment.

Modeling and Load Flow Analysis of a Microgrid Laboratory.

Microgrids-miniature versions of the electrical grid are becoming increasingly more popular as advancements in technologies, renewable energy mandates, and decreased costs drive communities to adopt them. The modern microgrid has capabilities of generating, distributing, and regulating the flow of electricity, capable of operating in both grid-connected and islanded (disconnected) conditions. This paper utilizes ETAP software in the analysis, simulation, and development of a lab-scale microgrid located at Cal Poly State University. Microprocessor-based relays are heavily utilized in both the ETAP model and hardware implementation of the system. Three case studies were studied and simulated to investigate electric power system load flow analysis of the Cal Poly microgrid. Results were compared against hardware test measurements and showed overall agreement. Slight discrepancies were observed in the simulation results due mainly to the non-ideality of actual hardware components and lab equipment.