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Readymade Garments (RMG) sector in Bangladesh has rapidly attained high importance for a high contribution to GDP for more than the last 30 years. 80% of the motor used in these industries for sewing machines are inefficient clutch... more
Readymade Garments (RMG) sector in Bangladesh has rapidly attained high importance for a high contribution to GDP for more than the last 30 years. 80% of the motor used in these industries for sewing machines are inefficient clutch motors. As a result, these RMG sectors suffer from huge power loss from the very beginning. An efficiency improved device can make huge differences in power consumption and energy savings annually. This paper shows a clear scenario of the RMG sector's annual power consumption data and power losses due to inefficient devices. A single-phase Variable Frequency Drive (VFD) based efficient sewing machine is also presented here. Annual statistical analysis on the energy efficiency and savings of energy-efficient sewing machines is carried out to provide a clear image of energy losses and possible energy savings of the last 10 years in the RMG sector of Bangladesh. A case study is also presented after implementing a VFD based energy efficient sewing machine by showing the possible economic benefits.
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This paper presents a solar-powered DC/AC drivetrain design for an electric boat with a portable irrigation system. The optimal boat has 35 PV modules each of 95W (total 3. 3kW), 20 Lead-Acid batteries of 12V90Ah (total 21kWh) as power... more
This paper presents a solar-powered DC/AC drivetrain design for an electric boat with a portable irrigation system. The optimal boat has 35 PV modules each of 95W (total 3. 3kW), 20 Lead-Acid batteries of 12V90Ah (total 21kWh) as power sources. An induction motor (IM) of 5HP to run the boat and a pump of 3HP for irrigation are the primary loads of the drivetrain. Two 3-phase inverters will control the IM motors. On the storage side, a bi-directional buck-boost converter controls the charging and discharging process. These three controllers operate in MPPT (Maximum Power Point Tracking) mode to capture maximum energy from the solar array that provides 300V of DC optimum transmission voltage. A steel-wooden boat fabricated to carry 100 peoples with the PV modules on the rooftop. The boat’s maximum speed is 5 knots, with a total duration of cruising on a sunny day is around 10 hours. The pump used to irrigate surface water to cover 4 acres of land daily. The performance was justified by the practical implementation to a countryside river.
Irrigation plays a major role in food security all over the world. In rural areas, single-phase power is mostly available, which is why most irrigation systems consist of single-phase induction motors. The performance of these systems... more
Irrigation plays a major role in food security all over the world. In rural areas, single-phase power is mostly available, which is why most irrigation systems consist of single-phase induction motors. The performance of these systems depends heavily on the quality of power available. Often times, the voltage delivered to the load is lowered due to transmission line drops and inadequate power generation. As a result, the current drawn by the loads increases and system efficiency falls. This paper presents the experimental findings of two single-phase submersible pump systems in which the voltage supplied has been varied. In one of the systems, the effects on system performance of incorporating a single-phase variable frequency drive (VFD) before the power reaches the load is investigated. A comparison between input power and flowrate has been made for each system. It is seen from the results that the flowrate at any particular input power is greater for the system with VFD, implying...
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This paper presents a circuit topology for portable Shielded Metal Welding Machine (SMAW) integrated by soft-switching PWM full-bridge dc-dc power converter that can work with both utility grid 220Vac or solar DC 300Vdc as the input... more
This paper presents a circuit topology for portable Shielded Metal Welding Machine (SMAW) integrated by soft-switching PWM full-bridge dc-dc power converter that can work with both utility grid 220Vac or solar DC 300Vdc as the input source. The power circuit maintains zero voltage switching (ZVS) to reduce switching losses. This technique leads the circuit to operate at a high switching frequency of 20 kHz. High switching frequency with the softer Pulse width modulation (PWM) converter, the better will be the performance with high-frequency (HF) transformer and passive components. Thus, the power density and operational efficiency will be higher compared to a typical hard switching converter. Considering ac input from the utility grid, a boost converter has integrated to improve power factor (PF) and lower THD. A 1 kW prototype is designed and developed that consists of a rectifier, boost converter, full-bridge inverter, HF ferrite core transformer, LC filter, and welding accessories (clamp, electrode, etc.). The effectiveness is tested under low voltage (LV) and high current (HC) situation as an arc welding machine by using both grid and photovoltaic (PV) array.
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ABSTRACT Photovoltaic cell converts solar energy directly into electricity. This paper describes a design of a charge controller to get the maximum power by using the Pulse Width Modulation (PWM) technique. In this paper PWM is controlled... more
ABSTRACT Photovoltaic cell converts solar energy directly into electricity. This paper describes a design of a charge controller to get the maximum power by using the Pulse Width Modulation (PWM) technique. In this paper PWM is controlled by the PIC Microcontroller. The work of the paper is to charge a 12 volt battery by using a 50 watt solar panel with maximum power. In this paper how maximum power can be achieved from solar panel to charge the battery through PWM signal generated by microcontroller is discussed and the experiments by taking voltage and current's values in different time interval are shown. Finally the experimental results are illustrated in this paper.
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In this research, we have designed and developed an EOG-based Electric Wheelchair system for patients suffering from Quadriplegia or Quadriparesis or similar condition where a person is not only unable to walk but also unable to move... more
In this research, we have designed and developed an EOG-based Electric Wheelchair system for patients suffering from Quadriplegia or Quadriparesis or similar condition where a person is not only unable to walk but also unable to move fingers to press a button. The designed EOG recorder is used to capture intentional eye blink and eye movements (i.e. EOG signals) performed by the patient sitting in the Wheelchair. The recorded EOG signals are then processed in Arduino platform and converted to command signals to control the movement of the wheelchair in four directions (i.e. left, right, front and back) from four different EOG signals (i.e. left, right, up and down eye movements) along with start and stop commands from intentional eye blink signals. The electric wheelchair is also designed and implemented by converting a normal chair to wheelchair with necessary motors (2 DC brushed motors), wheels, and control circuitry along with the battery power supply. The EOG system is portable, wireless and user friendly which can be worn by the patient to control the wheelchair. Test experiment with subjects suggests that the proposed EOG system can detect different eye movements with an average accuracy of 90% in controlling the wheelchair. The overall cost of the developed system is around 20,000 BDT which is affordable. The proposed system has a huge potential to be used by our country’s rural and middle-income people suffering from similar disability who can’t afford commercially available expensive automated electric wheelchairs. This work can be further modified to use in other applications for the same type of patients such as EOG controlled mouse cursor for computer use. Thus this EOG-based human-machine interface applications can significantly enhance the quality of life for such middle-income or lower-middle income patients living in the developing countries such as Bangladesh.
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The rapid growing battery-powered and plug-in hybrid electric vehicles will have a significant impact on power networks due to their zero carbon emission and mass deployment. DC motors, AC induction motors, and Brushless Direct Current... more
The rapid growing battery-powered and plug-in hybrid electric vehicles will have a significant impact on power networks due to their zero carbon emission and mass deployment. DC motors, AC induction motors, and Brushless Direct Current (BLDC) motors are used worldwide in electric vehicles for years. Among them, BLDC motors are one of the electrical drives that are continually gaining popularity in motion control applications due to their high efficiency, good dynamic response and low maintenance. Unlike DC motors and Induction motors, BLDC motors need a controller as the motors run in 3 phase but take DC input. The controller converts DC power to 3 phase AC power suitable for the motor. This paper describes the design and development of a BLDC motor controller and its performance comparison with the existing BLDC motor controller imported from abroad. The controller circuit is simulated in Proteus software and the PCB is designed in ARES.
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This paper presents a high-power density onboard integrated charger with multiple outputs-based H-bridge converters for BMS (Battery Management System) integrated li-ion battery bank used in upgraded electric vehicles. The proposed... more
This paper presents a high-power density onboard integrated charger with multiple outputs-based H-bridge converters for BMS (Battery Management System) integrated li-ion battery bank used in upgraded electric vehicles. The proposed converter can operate as AC to DC battery charger and to transfer power from the supply grid to multiple battery packs through discrete BMS of the system drivetrain. The BMS controls over voltage, overcurrent, and temperature of the battery pack. This operation will be done more efficiently with the separate power supply to these discrete BMSs. To obtain a high efficiency and high-power density, an HF tapped-transformer is used to meet the requirement of improved system size and reliability by attenuating magnetizing and copper losses with high-switching frequency operation. But the traditional H-bridge circuit suffers from switching loss due to HF operation. To solve this, zero-voltage switching (ZVS) topology was integrated. The impact of the proposed t...
This paper proposes the design of an efficient zero voltage switching parallel quasi resonant inverter for small scale industrial and domestic applications using solar energy as the dc input and induction heating technology. The resonant... more
This paper proposes the design of an efficient zero voltage switching parallel quasi resonant inverter for small scale industrial and domestic applications using solar energy as the dc input and induction heating technology. The resonant inverter is designed using PSIM software and the designed model is verified using the PROTEUS software which operates for a frequency around 20KHz under ZVS condition for different equivalent heating workpiece resistance. The resonant frequency can be varied over a range by altering the duty cycle values. The detail design of the resonant inverter using PSIM and PROTEUS along with the simulation results of ZVS condition and data analysis are presented in this paper.
Research Interests: Engineering and IEEE
With the improvement of technology and economic enhancement, people are now using fuel or grid powered machine for food processing. Among all agricultural crops, rice is the main crop cultivated in Bangladesh and a high efficient... more
With the improvement of technology and economic enhancement, people are now using fuel or grid powered machine for food processing. Among all agricultural crops, rice is the main crop cultivated in Bangladesh and a high efficient processing is required for this. But excessive rise of fuel prices and limitation of power supply to the off grid areas is an obstacle for this sector. Ozone gas emissions for both fuel burning and power generation results in global warming and health issues due to inhalation of the smoke. Because of a good solar irradiation pattern, a solar powered rice husking machine can minimize this burden from the nation. The purpose of this paper is to design and analyse the performance of solar powered rice husking system. Physical demonstration was made by installing 2 kW crystalline PV modules by setting up the rice husking machine with VFD based 3-phase inverter and other measuring equipment in experimental building. Based on maximum solar irradiation, projected output is analysed by using PSIM simulation and the prospect of solar powered rice husking system in Bangladesh is shown with economic feasibility. Based on the experimental data, the performance of the system is also analysed and presented in this paper.
Research Interests: Engineering and Inverter
This paper presents multiple systems integration schemes with the solar micro-off-grid by using 3-phase variable frequency drive (VFD) inverters. The integrated system (IS) combines two crystalline photovoltaic (PV) arrays of 4.2kWp and... more
This paper presents multiple systems integration schemes with the solar micro-off-grid by using 3-phase variable frequency drive (VFD) inverters. The integrated system (IS) combines two crystalline photovoltaic (PV) arrays of 4.2kWp and 2.8kWp respectively. Considering small industrial applications, three distributed induction motor (IM) loads were installed i.e., two 3HP/2.2kW pumps and a 2HP/1.5kW motor. To minimize the power loss, an HV DC transmission line of350V was considered. The 3$-\varphi$ IM controllers ensure perturb and observation (P&O) maximum power point tracking (MPPT) operation to harness maximum power from the PV array. The 7kWp parallel system maintains an efficiency of over 90% from the PV array and the IGBT module based MPPT inverters keep running with an efficiency of 93%. The performance of the system is analyzed and verified using experimental data.
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Irrigation is a very common term in agricultural countries like Bangladesh. For small scale cultivation, farmers mainly use surface water for irrigation by lifting them manually or by portable diesel pump. This typical manual irrigation... more
Irrigation is a very common term in agricultural countries like Bangladesh. For small scale cultivation, farmers mainly use surface water for irrigation by lifting them manually or by portable diesel pump. This typical manual irrigation requires heavy labor and diesel pump requires fuels that are exhaustible and non-friendly to the environment. In this paper, the design and construction of a solar-powered portable-floating boat for small scale irrigation is showed. It will replace the typical systems with a clean, efficient and controlled performance and ensures the proper usage of surface water and make irrigation more comfortable for farmers. A pump controller is used to run a single-phase water pump which ensures maximum power point tracking (MPPT) operation to extract maximum energy from solar. 3D model of the system was developed by using Google SketchUp and the pump controller was designed and simulated by using Proteus Design Suite software. The performance and economic feasibility of the proposed system are also evaluated in this paper by comparing it with an equal capacity conventional solar irrigation system.
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This paper aims to analyse the behaviour of a parallel quasi resonant converter for a proposed solar based induction cooking system under ZVS condition. The IGBT incorporated in the resonant converter will switch as a self oscillating... more
This paper aims to analyse the behaviour of a parallel quasi resonant converter for a proposed solar based induction cooking system under ZVS condition. The IGBT incorporated in the resonant converter will switch as a self oscillating circuit and operate under ZVS condition to minimize switching losses. The resonant converter simulation design responds to different equivalent pan resistances and it can be said that the equivalent pan resistance of 5Ω will provide the maximum efficiency of the system at a resonant frequency of 20KHz. The resonant frequency can be varied by changing the duty cycle parameter in the control part of the design for a range of 14KHz ∼ 33KHz. The output power of the cooking pan is seen to vary for different pan resistances to obtain an efficiency of the system that varies within the range of 75% ∼ 93%. The resonant converter was designed and analysed in PSIM software to show these analysis.
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For simple structure and lower maintenance cost, electric vehicles are popular in this sub-continent. As passenger vehicles, easy bikes are being widely used in Bangladesh. Mainly, iron core transformer based bulky chargers with... more
For simple structure and lower maintenance cost, electric vehicles are popular in this sub-continent. As passenger vehicles, easy bikes are being widely used in Bangladesh. Mainly, iron core transformer based bulky chargers with efficiency lower than 80% are used to charge more than 10 million easy bikes. These inefficient chargers cause huge power losses to national utility grid. Moreover, manual controls of such conventional charger are bothersome to its user. Implementations of power electronics based chargers are able to operate in more than 90% efficiency which can reduce the power losses from utility grid. A high capacity synchronous buck converter based charger with built in intelligent system is proposed in this paper. An automated charging current control system is initiated. After the simulation by using PSIM software, a lightweight prototype of easy bike charger is built and its performance is evaluated for high output current. The efficiency and its maximum rated power is observed and compared with the conventional charger.
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The Ready-Made Garments (RMG) sector plays a huge role in the Bangladesh economy in terms of employment, foreign exchange earnings and its contribution to GDP. Mainly clutch motors are used in this industry which has no speed control, low... more
The Ready-Made Garments (RMG) sector plays a huge role in the Bangladesh economy in terms of employment, foreign exchange earnings and its contribution to GDP. Mainly clutch motors are used in this industry which has no speed control, low starting torque, energy loss through heat and motor burn problems, etc. A VFD based inverter can protect the motors from these problems. Moreover, a stand by position for controlling the speed by VFD during no-load time can make the system more energy efficient. But, an inversion process can affect the line power factor though it increases the system efficiency. In this paper, the field implemented data of a 1kW capacity VFD for clutch motors is shown. Efficiency improvement and distortion in PF is analyzed by field implementation and lab experiment. In addition, in this paper, a boost converter integrated VFD inverter is also analyzed for the specific capacity to get an ideal power factor with improved efficiency.
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This paper proposes an innovative approach to utilizing Buck converter as an ideal Power Factor Correction (PFC) controller where variable width Pulse Width Modulation (PWM) switching signals are generated and implemented to reliably... more
This paper proposes an innovative approach to utilizing Buck converter as an ideal Power Factor Correction (PFC) controller where variable width Pulse Width Modulation (PWM) switching signals are generated and implemented to reliably control the voltage and current conversion phenomena. The developed converter topology is tactically utilized to design an efficacious grid-connected electric vehicle charger with substantially ameliorated line Power Factor so that the system loss can be averted in the case of AC-DC charging circuits. In order to ensure the sustainability of the proposed method, PSIM simulation software has been used to emulate a simulation model of a Battery charging system for Electric vehicles. The simulated output and evaluated performance parameters provide almost unity Power Factor (PF) with a Total Harmonic Distortion (THD) rate of 4.62% which is lower than the maximum allowable value recommended by IEEE519. The simulation outcome corroborates the efficiency and validity of the proposed framework.
Research Interests: Computer Science and IEEE
Industrial scroll saws commonly powered by grid electricity, expensive, bulky, not portable, inefficient, and are not operational in off-grid areas. In this paper, a scroll saw is proposed and designed to run by both grid electricity and... more
Industrial scroll saws commonly powered by grid electricity, expensive, bulky, not portable, inefficient, and are not operational in off-grid areas. In this paper, a scroll saw is proposed and designed to run by both grid electricity and solar DC source. The initial target was to demonstrate a locally made Scroll Saw machine that can be easily replaced if any damage to the device as the whole machine is made of wood to minimize cost with enhanced reliability. In the system, a motor is powered by the solar panel by inverting the DC solar power to AC power. For avoiding high starting torque, 3-phase topologies are selected. This motor is used to move the rocker arm up and down, connected to the cutting blades. A high capacity 3- $\varphi$ inverter is designed to run the 3- $\varphi$ induction motor. The total system of 1kW capacity is implemented and tested in the field.
In Bangladesh with this immense problem of traffic the most compatible among all vehicles is bicycle. Though it is very user friendly, it requires massive amount of mechanical energy for pedaling for which the concept of incorporating... more
In Bangladesh with this immense problem of traffic the most compatible among all vehicles is bicycle. Though it is very user friendly, it requires massive amount of mechanical energy for pedaling for which the concept of incorporating electricity in bicycle came in mid-20th century. With the development of technology, the paper is focusing on developing an electric bike with recent technologies and to make it budget friendly for Bangladesh. For hardware implementation, PROTEUS simulator is used to design the BLDC controller by using Arduino IDE microcontroller. A Hub motor which is very sleek in design and very light in weigh, is considered for the electric bicycle. Lithium ion batteries was added for power backup because of its high energy density, low self-discharge rate and low maintenance. The mobility of the power supply was one of the main objectives so that it can be charged whenever it is needed.
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Brushless Direct Current (BLDC) motor are one of the electrical drives that are continually gaining popularity in motion control applications due to their high efficiency, good dynamic response and low maintenance. Unlike DC motors and... more
Brushless Direct Current (BLDC) motor are one of the electrical drives that are continually gaining popularity in motion control applications due to their high efficiency, good dynamic response and low maintenance. Unlike DC motors and Induction motors, BLDC motors needs a controller as the motor runs in 3 phases but takes DC input. The controller converts DC power to 3 phase AC power suitable for the motor. This paper propose a design, code generation method and digital logic control of a BLDC motor controller for turning the rotor clockwise or counter clockwise. A Pulse Width Modulation (PWM) speed control strategy is performed to adjust the rotor speed. The framework is modelled and simulated by using Proteus software.
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This study focuses on the implementation of web based low cost yet effective remote laboratory system for engineering education to utilize limited resources for improving engineering student's practical knowledge as well as self... more
This study focuses on the implementation of web based low cost yet effective remote laboratory system for engineering education to utilize limited resources for improving engineering student's practical knowledge as well as self learning ability. The proposed system provides practical experience to the students in the field of power electronics and telecommunications. This lab allows the students to perform experiment by controlling various experimental apparatus on real time from their home or any preferred location using the internet connection. Several experiments related to Power electronics and Telecommunications have been designed for this remote lab. The system is flexible and the range of laboratory experiments can be expanded as required without any complexity. This initializes an openly integrated environment which facilitates the sharing of not only hardware resources, but also educational material for enhancing engineering education in developing countries like Bangladesh.
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Depletion of Natural Gas and increasing price of LPG, burning wood, coal etc, are now the main menaces for cooking purposes in Bangladesh. On the other hand, inefficient burning of wood, charcoal, agricultural wastes and animal dung etc,... more
Depletion of Natural Gas and increasing price of LPG, burning wood, coal etc, are now the main menaces for cooking purposes in Bangladesh. On the other hand, inefficient burning of wood, charcoal, agricultural wastes and animal dung etc, generate smoke and emits ozone gases. This results in global warming and health issues due to inhalation of the smoke. Because of a good solar irradiation pattern, a solar powered conduction cooker can minimize this burden from the nation. The purpose of this paper is to design, analyse the prospect and performance of solar powered conduction cooking system by using Thin Film photovoltaic modules with a novel synchronous Buck Converter Controller topology. Physical demonstration was made by installing 1 kW Thin Film PV modules on the rooftop of the university building with setting up the conduction cooker and other measuring equipment. 10 panels of 95 Watt are mounted on the rooftop of the university building. Based on solar irradiation data round the year, projected output is analysed by using PSIM simulation and the prospect of solar powered conduction cooker in Bangladesh is shown with economic feasibility. The system was designed and analysed in PROTEUS software and the hardware was fabricated and implemented. Based on the experimental data, the performance of the system is also analysed and presented in this paper.
This paper documents an efficient, cost-effective and sustainable grid-connected electric vehicles (EVs) battery charger based on a buck converter to reduce the harmonics injected into the mains power line. To utilize the switching... more
This paper documents an efficient, cost-effective and sustainable grid-connected electric vehicles (EVs) battery charger based on a buck converter to reduce the harmonics injected into the mains power line. To utilize the switching converter as an effective power factor controller (PFC), inverse sinusoidal pulse width modulation (ISPWM) signals have been applied. A mathematical relationship between the sending-end power factor and the duty ratio of the switching converter has been presented. To ensure the sustenance of the proposed method, a simulation model of the proposed battery charging system has been tested on PSIM simulation platform. The simulation results yield to a lossless charging system with a sending-end power factor close to unity. An experimental testbed comprising a 60 V battery bank of 100 A-h capacity with a charging current of 7 A has been generated. The laboratory assessments present an 88.1% efficient charging prototype with a resultant sending-end power factor...
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This paper intends to develop a three phase induction motor controller for a solar powered water pump. In many areas, disrupted and inadequate power supply can cause significant damage in household or industrial activities which require... more
This paper intends to develop a three phase induction motor controller for a solar powered water pump. In many areas, disrupted and inadequate power supply can cause significant damage in household or industrial activities which require water supply. Agricultural production is also hindered as most of the irrigation process is solely based on electricity. So far, DC motors have been
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This paper is aimed to present the design of a single-phase grid tie photovoltaic inverter with practical implementation. Special consideration given to the fact that, unlike conventional standalone inverters, grid tie inverters are... more
This paper is aimed to present the design of a single-phase grid tie photovoltaic inverter with practical implementation. Special consideration given to the fact that, unlike conventional standalone inverters, grid tie inverters are required to fulfill some demands to be connected with the single-phase grid. The demands of the single-phase grid and photovoltaic module are fulfilled and tested through the
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We found well operational property of superconducting fault current limiter (SFCL) substituting variable reactor to dc link of the rectifier type SFCL without bias current source. We proposed double bridge configuration with mutual... more
We found well operational property of superconducting fault current limiter (SFCL) substituting variable reactor to dc link of the rectifier type SFCL without bias current source. We proposed double bridge configuration with mutual coupled dc inductor to implement variable reactor. In the hybrid bridge circuit of the SFCL, two superconducting coils: a trigger coil and a limiting coil connected in anti-parallel mode. Both the coils are magnetically coupled with each other and could have the same value of self inductance so that they can share the line current equally. In this paper, we describe the SFCL model in the PSCAS / EMTDC○ R simulator for three phase bus and three phase voltage source.