Design of smart meter for monitoring & controlling bidirectional power flow

Project Title

Design of smart meter for monitoring & controlling bidirectional power flow

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

Net metering is a mechanism which allows domestic or commercial users who generate their own electricity by some mechanism (renewable sources) to export their surplus energy back to the grid. So, for this purpose customers need a bidirectional meter which will calculate the imported as well as exported power to the grid. The main objective is to measure & control the power flow direction whether, it is flowing from grid to load, load to grid, or in both directions. Meter also measures the net record of the power for net billing mechanism. When customers export their surplus energy to the grid, the load pressure from the grid during the peak hours reduces. This product enhances the use of renewable energy sources, and as a result energy crisis reduces to a great extent.

Project Objectives

The main objective is to build up a single-phase bi-directional meter which will be able to measure and control the power flow direction. The whole mechanism would be automatically controlled by a microcontroller interfaced with calibrated circuit.

The meter will measure following quantities;

? Imported / Exported Real Power (kWh)

? Net Real Power (kWh)

? Power Factor

? Current & Voltage

? Last month import & Export units

Since the meter control the power flow direction, there could be following four possibilities;

? Only importing from the grid

? Only exporting from the grid

? Neither, importing nor exporting

? Importing as well as Exporting at the same time

Project Implementation Method

The flow diagram for the working of meter is shown below in the Figure 1. In the below diagram, the potential & current transformer measure the voltage & current respectively. The output of both transformers would be a low level quantity representing the same level i.e. as of input. Since microcontroller works on DC values so, the rectifiers convert AC values of voltage and current into DC levels. Power flow direction can be controlled by the microcontroller. After receiving the voltage & current levels, it will sent some instruction to the control circuit & then decided the power flow direction (from grid to load or load to grid). Different quantities (as mentioned above) will be displayed on the display of the meter.

Benefits of the Project

Before net metering concept, conventional meters were used which measures the power flow in only single direction (from grid to the load). To overcome the energy crises, customer can utilize the renewable energy sources like PV panels for their own use, and at the same time extra energy is directly exported to the Grid. So, for this purpose one need a Bi-directional Energy meter. Both, energy supplied to & consumed from the grid are measured. In the modern era this is most efficient & fresh idea and its customers are increasing day by day.

Technical Details of Final Deliverable

The final product will be a microcontroller based single-phase bi-directional energy meter. It will monitoring & controlling the power flow between load and grid. It will be automatically controlling the power flow direction, whenever to import or export power to the grid.

Final Deliverable of the Project HW/SW integrated systemCore Industry EducationOther Industries Energy Core Technology OthersOther TechnologiesSustainable Development Goals Quality Education, Responsible Consumption and ProductionRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	69000
Current Transformer	Equipment	3	5000	15000
Ppotentail Transformer	Equipment	3	5000	15000
Microcontroller	Equipment	2	2000	4000
Printed Circuit Board	Equipment	1	5000	5000
Electronic Devices	Equipment	10	2000	20000
Others	Miscellaneous	1	10000	10000