Automated power Factor Correction and Energy Monitoring System Project Supervisor: Dr. Mohammad Monirujjaman Khan Group Members: Yusuf Mohammad Mohsin Yasin Kabir

Outlines In this presentation session we are going to present the following terms of our designed project. Power Factor(PF) and its significance. Research objective and our contribution. Overview of the whole system. Different subsystems. Design approach. Complete prototype. Result analysis. Application and market research. Future development and Conclusion.

Research Objective and Our Contribution To determine the current power factor condition of the load. Improving PF factor level to minimize power wastage. Continuously monitoring power consumption of load. Our Contribution: Development of an efficient Power Factor corrector. Making the system automated and smart. Using microcontroller to make it cost effective, multifunctional and programmable. Combining an energy monitoring system with the PFC unit.

What is Power Factor? Power factor of a load is the ratio of Active Power (KW) to Apparent Power (KVA) of an electrical installation. It is a measure of how effectively the electric power is consumed by the load for useful power output. The power factor is unity for a purely resistive load. Capacitive load causes current to lead before voltage. While Inductive load causes current to lag behind voltage. Both results in the current and voltage waveforms to be out of phase with each other Fig: Inductor V-I Relationship Fig: Capacitor V-I Relationship

Why is Power Factor Important? Low power factor means higher apparent power is drawn from distribution network. A load with lower power factor draws more current than a load with higher power factor for the useful power. This leads to wastage of energy and poor electrical efficiency. Fig: Power Triangle

Causes of Low Power Factor Power factor in a system decreases with installation of non-resistive loads such as induction motors, fluorescent lighting etc. A low power factor is caused by a significant phase difference between current and voltage at the load. It can also be caused by harmonic content or distortion of current waveforms.

Proposed Solution for PF Improvement Developing a Microcontroller based power factor correction unit using capacitor bank. It will be feasible and cheaper to setup. Maintenance of the unit will be much easier and cost effective. Automated switching combination of capacitors will provide maximum utilization of capacitors.

Overview of The Complete System Fig: Block diagram of the complete System

Subsystems of the Project The whole APFC and Energy Monitoring System consists of the following subsystems:- Power supply Unit Voltage Sensor Circuit Current Sensor Circuit Microcontroller Unit Relay driver Capacitor Bank LCD Display

Design Approach Microcontroller takes processed input signals from the subsystems. An open source “Emonlib” library based power calculation algorithm is applied for power measurements. Some factors values are determined to convert the low amplitude calculated values to actual readings. Automated switching operation is programmed for addition of required capacitors. Continuously displays the load’s consumption parameters on LCD.

Designed Prototype Fig: Developed prototype of the APFC and Energy Monitoring System

System Flowchart Fig: Flowchart of the complete APFC System

Result Analysis To analyze the results of the system different power factor was introduced in the load side and the following performance was observed. When pf is in desired range (≥0.95) it doesn’t make any correction rather only displays the load condition. When pf goes down to 0.85,0.71,0.60,0.49; The microcontroller senses it and automatically switches 3.6µF,7.6µF,11.7µF,15.3µF respectively to rise the PF to (≥0.95) The LCD display continuously shows the load’s voltage, current, real and apparent power, power factor. Fig: Load condition before PF correction Fig: Load condition after PF correction

Application Any commercial power consumer facing low PF in loads. Utility companies who wants to ensure quality power supply. Mills and Industries to minimize electricity bills and penalty. Large buildings incurring significant inductive load usage.

Market research Use of Microcontroller made the system very cheap and energy efficient. As the device is programmable, it can be adjusted in different electrical systems. Multiple functions are possible simultaneously because of use of Microcontroller. Programing algorithm is much simpler than others developed APFC in modern times. Emonlib algorithm ensures minimum error in power calculations if properly configured. Total set up cost is much less than the existed PFCs in the market.

Future Improvement Data read and calculated by microcontroller can be passed to Personal computer for advanced. More powerful tools such as Matlab can be used to see the current and voltage waveforms in real-time graphical representation. Harmonic filtering system can be embedded with the APFC system to handle the harmonic distortions incurred by non-linear loads.

Conclusion Lagging power factor is determined accurately and corrected to the targeted level immediately. Capacitance requirement is checked continuously to prevent over correction. Very less error percentage (2%-3%) in calculating voltage, current and power factor. Automated operations ease the operation of the device and make life flexier. Incessantly monitoring load conditions on display.

yusuf.mohsin@northsouth.edu monirujjaman.khan@northsouth.edu Any Question? Thank You ! yasin.kabir@northsouth.edu yusuf.mohsin@northsouth.edu monirujjaman.khan@northsouth.edu