Design and Implementation of Digital Power Quality Based Energy Meter

Power quality problems are manifested in voltage, current or frequency deviations causing malfunction of sensitive equipment. Integration of inverter connected PV and wind power plants, and rampant rise in nonlinear loads have led to harmonic problem in power system. Nonlinear loads and switched dev

Project Title

Design and Implementation of Digital Power Quality Based Energy Meter

Project Area of Specialization

Wearables and Implantable

Project Summary

Power quality problems are manifested in voltage, current or frequency deviations causing malfunction of sensitive equipment. Integration of inverter connected PV and wind power plants, and rampant rise in nonlinear loads have led to harmonic problem in power system. Nonlinear loads and switched devices energized by sinusoidal sources or linear loads and switched devices with non-sinusoidal sources, produce harmonics in distribution system. Academic harmonic analysis study consists of modeling nonlinear loads to develop Norton and Thevenin equivalent circuits of devices for integration into harmonic analysis software. Experimental researchers often use harmonic analyzers to measure the harmonics in real systems to evaluate suitable mitigation alternatives. The distortive power losses force utilities to increase apparent power to maintain reliable and uniform power supply. Harmonic analyzers use data acquisition hardware and inbuilt software algorithms to perform onsite measurements. Harmonic analyzers help find true power factor, total harmonic distortions, reactive and distortive power losses.

The objective of this research is to design an energy meter using microcontroller which can measure true power factor by finding distorted power factor.  The performance of energy meter depends upon selected parameters, current extraction method and calculation of harmonics present in the signal.Controller will take current and voltage signal by the help of transducers. By using the current signal, we will find Total Harmonic Distortion (THD) by designed algorithm, and will be displayed on a LCD screen.With This THD value calculated, Distorted Power Factor (DPF) will be calculated so that we can find the True Power Factor(TPF) .After finding the TPF active power consumed will be find and displayed on screen.

Project Objectives

At a time when lean manufacturing has become the mantra of industry, minimizing energy costs

has assumed ever greater importance. It’s not just a matter of controlling consumption, however,

but of how that consumption is billed by the utility. This is where power factor plays a key role.

The objective of this project are to design an algorithm which can measure Voltages (V),Current (A), Active Power(W), Energy in Kilowatt Hours(KWh) ,Reactive Power(VAR).The second objective of this project is to develop algorithms for microcontroller for the calculation of Harmonics and Total Harmonic Distortions(THD) presents in the current and voltage signals. THD of signals will be calculated by using special designed algorithms for   Arduino    microcontrollers.

The given power quality detection unit can measure Total Harmonic Distortion(THD)and specifically Distorted Power Factor (DPF) along with Displacement Power Factor(TPF) for electrical power systems. The Discrete Fourier Transform (DFT’s) algorithm is the building block in this scenario. The basic need of DFT in harmonics analysis is the decomposition of current signal into its   frequency components of  distorted  signal  up to particular or   significant order.  

In the nutshell, main objective is to find amplitude of each frequency component and to then apply total harmonic diction equation review by using microcontroller.

The important point of our research in our project and power systems is to identify and estimate the time varying real time harmonics present. And this will be done by designing a portable hardware based energy meter which can measure Harmonics and Power quality parameters described above.

Project Implementation Method

The basic prupose of our project is to find the Total Harmonic Distortion(THD) present in the current and voltage signals.By finding this we can easily calculate the true power factor.Fast Fourier Series is the one among the Fourier Series which is implented practically to find the Harmoics in a signal,So we are using FFT to find the THD in the current signal.In a voltage signal distortion produced is almost 10% of the total so it can be ignored.

The main steps involving in the implentation of FFT are following:

1. Two signals are required for the computation of active power  that are current and voltage signals,Current signal will be fetched from the current transformer and voltage signal from voltage sensor ,it can be a potantial transformer.
2. After fetching the signals the whole work is on the shoulder of controller and designed algorithm of FFT.
3. For the calculation of THD following formulae will be implemented through algorithms.
4. These algorithms are sepecially designed for Arduino Microcontroller for precise and easy coputation.
5. After finding the THD we can calculate Distortion Power Factor and Displacement Power Factor And thus we can find True Power Factor using this equation:
6.  By finding True Power Factor we will be able to find true  active power absorbed by the load which is our main purpose.
7. After the calculations through algorithms next target is to display the calculated results on a LCD screen.

Benefits of the Project

This project is a contribution to  our WAPDA caompany  design a microcontroller based Energy Meter having following features:

1. This will be able to monitor our power systems by finding total power consumed.That is to protect our whole power system through checking the power quality used by the costomers,if they using load full of distortion which is causing our national grid harmonically distorted ,then to fine them and getting the true amount invested in power generation.
2. This Energy Meter will be able to find power quality parameters like active power, reactive power of the load.
3. The distorted power factor and displacement power factor will be find for finding true power factor.

Technical Details of Final Deliverable

Power quality is famous term being used and IEEE set standards for harmonics. The standard which addresses harmonics is referred to as IEEE-519. This standard details the recommended practices and requirements regarding harmonic control in electrical power systems. Harmonic is not new term in power system; it is being used since 1920. Transformers are major source of harmonics at that time but with revolution in electronic industry harmonics become major concern for power engineers. Due to excessive amount of these harmonics malfunction of electrical devices occurs. Harmonics are frequencies of AC currents and voltages other than fundamental frequency (50 Hz or 60 Hz). Harmonic distortion is degree to which pure sinusoidal value deviates due to addition of harmonics of different frequencies.

The increasing use of power electronic devices and non-linear loads in power systems has been creating significant harmonics distortion that can cause problems to computers and microprocessor based devices ,thermal stresses to equipment’s, losses in power systems, resonance risks in systems as well as impacts in facilities both in technical and commercial aspects.

Harmonics also effect the power factor of load by distorting it from true value. These distortion cause power factor to be distorted, And thus true power factor doesn’t remain same the ordinary displacement power factor instead it is the product of distorted power factor and displacement power factor.

More technically this meter will be able to deliever following things:

1. This Energy Meter will be able to calculate the Total Harmonic Distortion (THD) present in the current signal affected by the load.
2. This Energy Meter will be able to find power quality parameters like active power, reactive power of the load.
3. The distorted power factor and displacement power factor will be find for finding true power factor.
4. This will be able to monitor our power systems by finding total power consumed.

Final Deliverable of the Project

Hardware System

Type of Industry

Energy

Technologies

Clean Tech

Sustainable Development Goals

Responsible Consumption and Production

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com