The objective of this paper is to study various methods adopted during the energy audit. Many countries are focusing on energy, not only enhancing the tenable power generation sources but also on utilizing the power more proficiently for economic utilization. The energy audit is an important parameter for all the developing and developed countries and they focus on energy efficiency, energy quality, and energy intensity. In the industrial, residential, and commercial sectors the top operating expense is found to be are material, machine, manpower, and energy. Identification of the energy-consuming sector is the prior attention to look for the energy-saving potential and quality improvement. Implementation of an energy audit can enhance the efficiency, quality of power, reduce the tariff of bills, and reduces the wastage of energy. The need for energy audits, different types of energy audits, various types of software used, and the energy audit report structure were presented in this paper.

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Energy audit: types, scope, methodology and report structure

A zigzag transformer is a key segment of the electric power system. The optimal design of the zigzag transformer is important for transformer designers to provide a required return path for earth faults and to ensure proper operation of a power system. The two most important parameters of the zigzag transformers are no-load losses and leakage impedance. The accurate calculation of both factors helps to minimize the overall cost of the transformer. Therefore, the prediction of leakage reactance in the zigzag transformer using analytical or numerical methods is an essential part of the early designing stages of the transformer. This paper provides several two- and three-dimensional finite element models. The main purpose of these models is to evaluate the accuracy of the different models for the calculation of the leakage reactance. An analytical formula and a complete procedure for the calculation of the leakage reactance in the zigzag transformer are also provided, which will help the researchers and transformer designer to optimize this type of transformer. The prototype is also manufactured and tested to verify the accuracy of the analytical method and finite element models for the calculation of the leakage reactance. The simulation and experimental results show that the finite element calculation cannot only obtain accurate leakage reactance values (magnetostatic analysis), but also provides better accuracy in the no-load losses (transient analysis).

Comparison of Analytical Method and Different Finite Element Models for the Calculation of Leakage Inductance in Zigzag Transformers

Received Sep 1, 2021 Revised Dec 22, 2021 Accepted Dec 29, 2021 Zero sequence blocking transformers (ZSBTs) are used to suppress third harmonic currents in 3-phase systems. Three-phase systems where singlephase loading is present, there is every chance that the load is not balanced. If there is zero-sequence current due to unequal load current, then the ZSBT will impose high impedance and the supply voltage at the load end will be varied which is not desired. This paper presents Third harmonic blocking transformer (THBT) which suppresses only higher harmonic zero sequences. The constructional features using all windings in single-core and construction using three single-phase transformers explained. The paper discusses the constructional features, full details of circuit usage, design considerations, and simulation results for different supply and load conditions. A comparison of THBT with ZSBT is made with simulation results by considering four different cases.

Indonesian Journal of Electrical Engineering and Computer Science

The three-phase four wires low voltage supply system to residential, commercial and production areas in the distribution system is implemented. The different nature of loads connected to the three-wire four-phase distribution system. It can be personal computers, automatic machines, variable speed drives, lighting ballasts and other electronic power equipment, which may produce a nonlinear characteristic cause zero sequence current to flow in the system in the neutral of supply system. This may cause a serious power quality problems, results in reduction. This paper present to reduce the harmonics currents and neutral overloading by using the zigzag transformer. The zigzag transformer is one of the solution to attenuate the neutral current and reduce the zero sequence harmonic currents of the distribution systems.

Analysis and Application of Zigzag Transformer in Distribution System for Mitigation of Triplen Harmonics

Energy audits are the easiest way to find the gap between energy supply and demand. Energy audit is a consumption index that normalizes the state of the energy crisis by providing savings plans. Any organization called a large electricity consumer the use of appropriate energy-saving technologies or solutions minimizes energy consumption. Collecting this information provides consumers the idea of improving energy efficiency and reducing costs. Energy control of lighting and management of electrical load audit work was carried out to evaluate energy consumption, therefore energy savings opportunities identified implementing energy-efficient equipment or technologies to be adopted at the institution to minimize the energy consumption. A comparative analysis of the energy flow has been done in ETAP software that uses existing types of equipment and efficient equipment. Effective energy audit process in the college of engineering can focus the employees to think of energy as a controllable expenses and tried to save it in their daily work.

Yakub Anwar Makandar

Papers

Analysis and Application of Zigzag Transformer in Distribution System for Mitigation of Triplen Harmonics

Audit and Analysis of Energy Utilization in Engineering Institution Buildings in Maharashtra