Power Monitoring and load balancing system

Project Title

Power Monitoring and load balancing system

Project Area of Specialization BlockchainProject Summary

INTRODUCTION Currently, consumption of electrical energy is the most common problem in smart home and building environments which the amount of electrical energy consumed by each device in real time is unknown. Accordingly, the monitoring of electrical energy consumption data of electrical equipment is becoming progressively important. In recent field of research, the design of efficient electrical management system for homes or buildings is an active subject. Electrical energy management system is the combination of technologies and services through home networking for an intelligent living environment. Smart power outlets are considered as the most commonly used electrical devices in modern home environments. They could measure consumption of electrical energy and control the operation of the electrical equipment. The intelligent power outlets have recently appeared as a new form for home energy management that can control electrical equipment and produce secure electrical environment [1-3]. Many researchers have contributed in the development of electrical energy meters. The first generation of these meters were electromechanical meters and then evolved to emulate the most accurate measurements, less expensive and safe which represented by electronic meters.

of the developments in the electrical energy meters. An intelligent technique to detect any new devices installed in a smart environment is presented . This technique capable to monitor and identify any load, but it is unable to accumulate power data. A smart home with a ZigBee-based power socket is constructed . The weakness of this system is appearing in the measuring of the electrical energy consumption. Another system with a ZigBee-based smart power outlet network is proposed for gathering power consumption data This system not has any protection in an emergency. A method that based on the ZigBee communication and infrared remote control is proposed to perform active control for reducing standby power using sensor information, but it lacks to overload protection and detection [11]. A ZigBee-based monitoring system with self-protection is constructed [12]. This system is equipped each power socket with an energy metering integrated circuit IC to compute power parameters from the socket. It produces a higher device costs and more complex circuit structure. In addition, they just focused on two sockets protection in a branch., the electrical energy management method has been designed and implemented to control, monitor, and save the electrical energy............

A three-phase load balance system is constructed by replacing the loads of some power sockets while the energy measuring system gives an idea about the amount of consumed electrical energy. Finally, the proposed comprehensive system can be represented as a three phase load balance smart meter...

Project Objectives

ANALYSIS OF BALANCED AND UNBALANCED LOADS The analysis of power loss reduction plan executed by Privolshki regional network company of 0.4 kV in Kazan, Russia showed that there was very little attention given to phase load balancing of 0.4 kV networks, besides the fact that the length of 0.4 kV is significant. At present time, asymmetrical or unbalanced loads are experienced almost in all 0.4 kV distributive networks. The causes of load imbalances in city networks is usually domestic consumers; in industrial networks – welding units of different capacity; in power lines – large arc furnaces, electric locomotives of alternating current, etc. A balanced three phase system is characterized by the same module and voltage in all the three phases. During unbalanced operation mode, voltage is not equally distributed in the phases. Unbalanced operation modes in electrical networks are caused by the following reasons: 1. Unequal loads in various phases, 2. Partial operation of lines and other elements in the network, 3. Different line parameters in different phases. The most common voltage unbalances occur due to imbalance distribution of loads in the phases. In urban and rural networks of 0.38 kV, voltage imbalances are mainly caused by connections of domestic single phase lighting systems and single phase domestic electrical appliances of low power rating. The number of such single phase appliances is too big and it needs equal distribution in phases in order to reduce imbalances in loads In high voltage networks, load imbalances are caused by powerful single phase electrical equipments and in some cases even three phase electrical equipments with unequal load demands in phases. The main sources of load imbalances in industrial power networks of 0.38 kV are single phase thermal installations, ore – thermal furnaces, induction melting furnaces, resistance furnaces and various heating installations. Welding devices of various capacities are also a merger contributor to imbalances in loads. Traction substations of railway transport electrified on an alternating current are a powerful source of load imbalances as the electric locomotives are single – phase electrical equipments. The load demand of an independent single – phase electrical equipment may now reach several megawatts.The inequality of parameters of overhead power lines in different phases occurs, for example, due to the absence of transposition supports on power lines or linear cycles. Transposition supports are unreliable and are sources of breakdowns and accidents. The reduction of the number of transposition support on power lines reduces damageability and increases the reliability of power lines. 

Project Implementation Method

A. The measuring module The measuring module works as a three-phase metering circuit. The electrical power meter is designed to sense and measure the consumed electrical energy in home to provide a balance load for the three-phase supply and monitor the current, voltage and electrical power per hour. The design and implementation of the three-phase energy metering circuit is achieved by using an Atmega2560 microcontroller circuit. Three ZMPT101B voltage sensors are used in this module to measure the voltage of each phase of the three-phase supply as shown in Fig.2 (a). The current passes at each phase in this module is measured by using the ACS712 Fully Integrated, Hall Effect-Based Linear Current Sensor IC as shown in Fig.2 (b). This sensor has a copper conduction path. The current passes through this path produce a magnetic field that converts by the Hall IC into a proportional voltage.

Six current sensors are used in this system. Three of these sensors are connected directly to the three-phase supply to measure the total three-phase supply currents. The other three current sensors are connected across the three controllable loads to measure the three-phase current drown by these loads. The controllable loads have the ability to change their connections to the three-phase supply. The difference between the supply currents and the controllable load currents represent the currents drawn by the uncontrollable loads. By knowing the currents drawn by the uncontrollable loads we can rearrange the connection of the controllable loads in a manner that gives the best balance to the three-phase supply currents. The electrical energy measurement in this module depends on the reading of both the current and voltage sensors. The real power is computed by taken the sum of the instantaneous values of current and voltage for several times and divide it by the number of these times.The monitoring module The monitoring module could monitor the current, voltage, power factor and electrical energy that consumed at each phase in main home breaker. The data which collected by the monitoring and control module are necessary to work of other modules and can be used to implement a smart meter system. The periodically monitoring of electrical energy consumed in home helps the customer to control and save the electrical energy. The HD44780 LCD has been used for the monitoring module which displays the information in 4 rows with 20 characters for each row.

Benefits of the Project

The load balance module The three phase load balance system is characterized by a three-phase balancing unit that represents the important part because it contributes in the load balancing of the three phase supply in order to reduce the probability of damages. This module can detect any device connected to the power outlet and then this module replaces the connection of this outlet to a suitable phase that satisfy the best balance among phases which, several contactors have been used for replacement process. If all homes in distribution station have the same balance system then this process make the load is balance which leads to prevent the phase fault, and also helps to use most of the electrical energy that generated by main station. Six relays (see Fig. 3) and six contactors are used in this module to swap three controllable loads (load A, load B and load C) among the supply phases as shown in Fig. 1. The relay boards are used as complete electrical isolation between the control signal and the controlled circuits.

A contactor is an electrical control switch used for switching an electrical power circuit, similar to a relay except with higher current ratings. The contactor has four components  The contacts are the current carrying part of the contactor. This includes power contacts and auxiliary contact. The coil provides the driving force to close the contacts. Auxiliary Block this is for additional auxiliary contacts. Unlike general-purpose relays, contactors are designed to be directly connected to high-current load devices.s the block diagram for contactors (C1, C2, C3, C4, C5 and C6), where each two contactors are used to swap one of the controllable loads (A, B and C) among the three supply phases.

The load balance algorithm This section describes the algorithm for measuring current, voltage, power factor, and electrical energy consumed by each phase. Also, this algorithm used to control the balancing of the three phase supply currents. The steps for investigation this algorithm is as follows: 1. Measuring the total current of each phase of the three phase supply IR, IS, and IT. Assume load A is connected to phase R, load B is connected to phase S and load C is connected to phase T.

2. Measuring the voltage of each phase of the three phase supply VR, VS, and VT.

3. Measuring the current of each the three controllable loads IA, IB, and IC.

4. Calculating the currents of the uncontrollable loads.

5. Construct the index values (third column) according to the following equation.  Where the variable i, j and k represent the status of contactors in load A, B and C. Values of these variable for each load are:

(0) for contactors status (C2,C4,C6 = OFF, C1,C3,C5 = OFF)

(1) for contactors status (C2,C4,C6 = OFF, C1,C3,C5 = ON) (2) for contactors status (C2,C4,C6 = ON, C1,C3,C5 = OFF).

Technical Details of Final Deliverable

EXPERIMENTAL RESULTS

Two experiments are implemented to test the performance and accuracy of the load balance and monitoring system. The first experiment  is used to test the accuracy of the load balance system with respect to the laboratory reading. The experiment is repeated for different loads and the results recorded in three tables. The table 2 is for measuring the currents with respect to (Fluke 325) clamp meter which has 2% accuracy. The table 3 is to compare the voltage reading with respect to the (Fluke 83V) Industrial Multi-meter which has ±(0.5% + 2) accuracy . The table 4 is to compare the power factor and consumed power for different values of loads with respect to the (Fluke) wattmeter has ±(0.5% + 2) accuracy. All the results show that the designed system produces good accuracy with respect to the laboratory reading.

The second experiment is to test the performance of the designed balance system with respect to number of controllable loads. That is mean, the experiment is repeated for different number of contactors since each controllable load needs two contactors for swapping among supply phases.  that as the number of controllable loads increases the currents balancing among supply phases also increase. From this figure we found that five controllable loads give about 90% currents balancing accuracy and 100% accuracy needs more than five controllable loads. The increasing of the controllable loads leads to increase the cost because the numbers of contactors also increase.CONCLUSIONS In this paper a proposed system for measuring, balancing and monitoring the three-phase supply in smart meter is introduced. This system has a good accuracy with respect to the laboratory reading when measuring the three-phase currents, voltages, powers and power factor. This system investigates the load balancing with a good percentage when used three controllable loads. The measuring system helps the user to take an idea about the amount of kilowatt hours consumed by customer that helps to take a right decision to minimize the using of electrical energy and also, it is useful in design a smart meter for each home. The designed system has the feature to use the local wire for each power socket in main electricity circuit. This means we not need to use a wireless system to transfer the measuring data to main control system. This system can be scalable to balance the loads on the reign power transformer by applying it on all the homes connected to this power transformer. This process helps to reduce the occurrences of phase fault and helps to balance the loads on the main power station.

 An automation model that can switch some loads of when the system is at risk and switch AC supply from the utility of when batteries are full and the panels are generating enough power.
 

Final Deliverable of the Project HW/SW integrated systemType of Industry Energy Technologies OthersSustainable Development Goals Affordable and Clean EnergyRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	65500
Arduino uno , transistor 5, wires , relay ,and other some things use	Equipment	1	65500	65500