In Kerala (India), the energy consumption is monitored and calculated by frequent field visits by technicians from the electricity/energy department for the calculation of energy fare which is a time-consuming task as there will be thousands of houses in the area. There is no provision to check or analyze the individual energy consumption of houses in a period of time nor to create a report of energy flow in a certain area. This is not just the case of Kerala, but throughout many places in the world. I am proposing a smart energy monitoring system with the help of Arduino to ease the inspection, monitoring, analysis, and calculation of energy fare. The system by constantly uploading energy consumption data (using a unique user ID) to a cloud database with the help of cloud connectivity of the device. It will additionally allow generating user specific or area specific charts and reports to analyze the energy consumption and energy flow of an individual house or a region.

Supplies

Arduino Uno
LCD Display
Current Sensor (ACS712)

Step 1: Introduction

In Kerala (India), the energy consumption is monitored and calculated by frequent field visits by technicians from the electricity/energy department for the calculation of energy fare which is a time-consuming task as there will be thousands of houses in the area. There is no provision to check or analyze the individual energy consumption of houses in a period of time nor to create a report of energy flow in a certain area. This is not just the case of Kerala, but throughout many places in the world.

This project involves the development of a smart energy monitoring system that will ease the inspection, monitoring, analysis, and fare calculation of energy. The system will additionally allow generating user specific or area specific charts and reports to analyze the energy consumption and energy flow. The system module which will be given a unique user code to identify the particular housing unit where the energy consumption has to be measured. The power consumption will be monitored with the help of a current sensor interfaced to an Arduino board using an Analog connection. The energy consumption data and the unique user code of the user will be uploaded to a dedicated cloud service at real-time. The data from the cloud will be accessed and analyzed by the energy department to calculate individual energy consumption, generate individual and collective energy charts, generate energy reports and for detailed energy inspection. An LCD display module can be integrated into the system to display real-time energy measurement values. The system will work independently if a portable power source such as a dry cell battery or Li-Po battery is attached.

Step 2: Workflow

The main focus of this project is to optimize and reduce energy consumption usage by the user. This not only reduces the overall energy costs but will also conserve energy.

Power from the AC mains is drawn and passed through the current sensor which is integrated into the household circuit. The AC current passing through the load is sensed by the current sensor module (ACS712) and the output data from the sensor is fed to the analog pin (A0) of the Arduino UNO. Once the analog input is received by Arduino, the measurement of power/energy is inside the Arduino sketch. The calculated power and energy is then displayed on the LCD display module.
In AC circuit analysis, both voltage and current vary sinusoidal with time.

Real Power (P): This is the power used by the device to produce useful work. It is expressed in kW.

Real Power = Voltage (V) x Current (I) x cosΦ

Reactive Power (Q): This is often called imaginary power which is a measure of power oscillates between source and load, that does no useful work. It is expressed in kVAr

Reactive Power = Voltage (V) x Current (I) x sinΦ

Apparent Power (S): It is defined as the product of the Root-Mean-Square (RMS) Voltage and the RMS Current. This can also be defined as the resultant of real and reactive power. It is expressed in kVA

Apparent Power = Voltage (V) x Current (I)

The relation between Real, Reactive and Apparent power:

Real Power = Apparent Power x cosΦ

Reactive Power = Apparent Power x sinΦ

We are concerned only on the Real power for the analysis.

Power Factor (pf): The ratio of the real power to the apparent power in a circuit is called the power factor.

Power Factor = Real Power/Apparent Power

Thus, we can measure all form of power as well as power factor by measuring the voltage and current in the circuit. The following section discusses the steps taken to obtain the measurements that are required to calculate energy consumption.

The AC current is conventionally measured by using a Current Transformer. ACS712 was chosen as the current sensor because of its low cost and smaller size. The ACS712 Current Sensor is a Hall Effect current sensor that accurately measures current when induced. The magnetic field around the AC wire is detected which gives the equivalent analog output voltage. The analog voltage output is then processed by the microcontroller to measure the current flow through the load.

Hall Effect is the production of a voltage difference (the Hall voltage) across an electrical conductor, transverse to an electric current in the conductor and a magnetic field perpendicular to the current.