SMART METERS FOR MONITORING POWER QUALITY IN DISTRIBUTION GRIDS
D.S.De Silva, Eranda W.R, Kudahetti R.M,Madusanka A.W.A.V, K.M.I.U. Ranaweera
Power quality (PQ) in the distribution grid has to be maintained within the standard limits set by the regulatory bodies in the country since poor PQ causes problems to the end customers like equipment damages, high expenditure cost in industrial sector etc. Power quality can be defined as a steady supply which has a pure sinusoidal wave. Present world is moving towards distribution generation. Due to expansion of renewable energy-based generation (REG) and electric vehicle charging stations (EVCS) in Sri Lanka, introduce PQ disturbances like voltage variations for long time and short time durations, harmonics, flickers, power interruptions etc. To take necessary actions to overcome these PQ issues, continuous monitoring is essential. There are PQ monitoring devices which are expensive but continuous monitoring cannot be achieved.
Key Words:Power Quality,REG,THD
Overview
In Sri Lanka, there is no any method to perform real time PQ monitoring in the distribution grid. In this project we have developed a new system which can perform real time PQ monitoring in the distribution grid. A smart meter is developed to acquire grid parameters to monitor PQ. Those measured data are transmitted to a central station (relevant grid substation) by using cloud-based technology. Then real time PQ monitoring can be done through the graphical user interface (GUI) by the utility. GUI is developed by using MATLAB and composes with the functions to monitor PQ indices like, overvoltage and undervoltage conditions of three phases, current and THD value exceeding, power factor and phase unbalance of the end user. Real power and reactive power consumption, rms values of voltage and current monitoring are also capable through the GUI. A mobile app is also developed by using Android Studio 2.2.3 to monitor PQ. When exceeding the limits of PQ parameters, a SMS alert is received to the mobile phone of the operator. Then he/she can monitor the system by using the mobile app. Both of these monitoring methods are used by the utility in order to perform real time monitoring. This proposed smart meter is capable of measuring PQ indexes like total harmonic distortion, voltage, current and frequency variations and power factor. This system costs around Rs. 50000 and also has the ability to perform real time PQ monitoring and observe past records.
Project Contacts: saman@eie.ruh.ac.lk
Publications
- Real-Time Power Quality Monitoring System for Distribution Grid, D.S. De Silva,(Ms.) R.M. Kudahetti, W.R. Eranda, A.W.A.V. Madusanka, and K.M.I.U. Ranaweera, IESL transactions 2019-part-B technical papers page 207-213
- Real-Time Power Quality Monitoring System for Distribution Grid, D.S. De Silva,(Ms.) R.M. Kudahetti, W.R. Eranda, A.W.A.V. Madusanka, and K.M.I.U. Ranaweera, present around the world 2019, IET annual Technical Conference papers page 37-42
- Smart meters for Monitoring Power Quality in Distribution Grid, D.S. De Silva,(Ms.) R.M. Kudahetti, W.R. Eranda, A.W.A.V. Madusanka, and K.M.I.U. Ranaweera, Poster presented in 16th academic session of university of Ruhuna,6th March,2019.
