An IoT Based Household Power Management System

Pakistan is facing power shortages, and it has to find the alternate sources of energy. One possible solution to the problem is to turn to the renewable energy. Photovoltaic (PV) is suitable for Pakistan because it gets increased exposure to the sun throughout the year. PV energy is clean, and has l

Project Title

An IoT Based Household Power Management System

Project Area of Specialization

Internet of Things

Project Summary

Pakistan is facing power shortages, and it has to find the alternate sources of energy. One possible solution to the problem is to turn to the renewable energy. Photovoltaic (PV) is suitable for Pakistan because it gets increased exposure to the sun throughout the year. PV energy is clean, and has low maintenance cost. Although the PV is the best and quickest solution to provide power, it suffers from a disadvantage that its output power depends on the environment. In a cloudy weather, the output power reduces considerably. So, it must have batteries in the system to provide the extra power in cloudy weather and at night.

Every PV system has limited power storage capacity because of the limited numbers of batteries. So, it is very important to use the available energy in the most efficient way. The non-critical loads must be turned off under cloudy weather, and at night when the batteries are not fully charged. The worst-case scenario is when the PV system has maximum possible load and the batteries are not sufficiently charged and the PV panels are suddenly covered by the clouds. The load on the PV system must be lowered very fast otherwise the system can be damaged. Turning off the loads manually is not easy. There must be a system that monitors the power extracted by the PV panels, and adjusts the load accordingly.

In this project, a ‘smart plug’ concept is introduced. This plug will be capable of measuring the voltage, current and power delivered to the load in real-time. There is a relay in the plug that can disconnect the load from the source. These ‘smart plugs’ are capable of sending the measured voltage, current and power to a central controller. With this information, the central controller can measure the total power consumed by all the loads in real-time. Depending on the available power from the PV panels, the central controller can automatically turn on and turn off the load connected to any ‘smart plug’. Thus, the central controller can manage the whole PV system.

The purpose of the work is to propose a ‘smart plug’ that can work with the PV systems to efficiently utilize the available power from the PV panels. The proposed system consists of the following three sub-modules,

a) Smart Plug

b) Central Controller

c) Cloud-based System

The smart plug is responsible for measuring the voltages, currents, power and power-factor. It has a two-way communication with the central controller. All the smart plugs are connected wirelessly to the central controller that is responsible for managing the whole system. The central controller takes decision about what loads need to be connected to the PV system and what loads need to be disconnected based on the preferences set by the user. It also sends the system information to the cloud that can be accessed by the user from anywhere in the world.  

Project Objectives

The goal of the proposed system is to smartly manage the energy extracted from the PV panels. This system will be able to connect and disconnect loads depending on the available power from the PV panels. The main objectives of the system are to,

i) Measure the AC power from the measured voltage and current.

ii) Control the relay to connect and disconnect the AC load.

iii) Design a ‘smart’ Controller that keeps account of available PV power, energy stored in the batteries and total AC load.

iv) Have a two-way communication between the ‘smart plugs’ and the Central Controller

v) Have a two-way communication with the cloud-based system

Project Implementation Method

The proposed system consists of the following sub-modules,

a) Smart Plug

b) Central Controller

c) Cloud-based system

The smart plug consists of AC voltage and current measuring sensors, a microcontroller and a Wifi module. The central controller has a microcontroller, and a Wifi router. The cloud-based system has a database that stores the data uploaded by the central controller. It also has a web and App interface for a user to monitor the data and to configure the system.

Project Implementation Stages:

The hardware and the software for the system are developed in parallel. Different implementation stages are listed below,

Simulations:

In the first stage, a simulation model of each sub-module is built in Proteus. This model is used to verify the operation of the system. The sensors design is also verified, and the waveforms are stored that will be used a dummy data for the Firmware development and sensor calibration.

Testing the system with off-the-shelf (OTS) sensors:

The first prototype of the system is built using OTS sensors. This prototype is tested with power-supplies and heater. Different real-world scenarios are emulated using these power-supplies and loads. All these tested are performed to verify the system (Hardware and Firmware) design.

Schematics and PCB Design:

Once the first prototype with OTS sensors is tested with all the real-world scenarios, the schematics of this system is designed in Altium. After carefully designing the schematics, the Printed Circuit Board (PCB) is designed. Since this power-stage has to process very high voltage and power, special care has to be taken. The creepage and clearance of the traces are checked.

Once both the schematics and PCB designs are validated, PCB design files are sent for fabrication.

Low-Voltage (LV) and Low-Power Testing of the PCB Boards:

Once the PCBs are fabricated, the components are soldered on the board. The LV circuits like the power-supplies, sensors and relays are tested first. Once all the LV circuits are tested at all corner cases, the boards are ready for low-power testing. The load is increased in small steps. After these LV and low-power tests, the boards are ready for high-power testing.

High-Power Full Load Testing:

After validating the hardware design at low-power, the boards will be tested at high power now. The output power is increased in small steps up to full load. The sensors are tested at full load. With these tests, the hardware design is validated.

Benefits of the Project

The benefits offered by the proposed system are,

i) It is indigenously developed.

ii) It will maximize the efficient use of energy stored in the batteries in PV systems that will result in availability of power for a longer time

iii) It is compact, has a longer life and will efficiently utilize the energy. Such a feature currently not available with the PV systems available in the market

iv) It is ‘smart’ in the sense that after detecting the shading on the panels, it can adjust the load.

v) It has a Cloud-based telemetry and control system. With this feature, the PV system can be monitored and controlled from anywhere in the world.

vi) This system can be used by any user getting electric power from any source (not just PV system). The user can turn on and turn off a particular load from anywhere in the world.

Technical Details of Final Deliverable

The end product of this project is a smart Energy Management System for residential PV applications. The designed system will have smart plugs (capable of measuring the AC and DC power), central controller and cloud-based telemetry and control system.

Final Deliverable of the Project

HW/SW integrated system

Core Industry

Energy

Other Industries

Core Technology

Internet of Things (IoT)

Other Technologies

Sustainable Development Goals

Responsible Consumption and Production

Required Resources

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