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2015-09-27
Technical Paper
2015-28-0001
Shashikiran HK, Bhupesh Agrawal, Neal Clements, Richard Wainwright
Bus bars are very critical components for power distribution in Electric Drive systems. The increase of power electronic components on vehicles, and their interaction, has increased the possibility of noticeable and destructive amplitude harmonics at resonant frequencies to exist in the power distribution network. The presence of stray inductance of bus bars along with the capacitance of the inverters creates a resonant circuit, which in turn can create instability in the system, so it is very critical to understand the performance and placement of Busbars in the system. As impedance is very much influenced by the geometry, shape, and materials of the bus bars, simulation tools can be utilized to accurately predict the impedance and this can be utilized to study the performance of the complete system and further optimize the busbar geometry as per system needs.
2015-09-27
Technical Paper
2015-28-0002
Abhijit Kulkarni, Vinod John
Second-order generalized integrator (SOGI) based phase-locked loops (PLLs) are used for grid voltage synchronization in single-phase grid-connected power converters. SOGI-PLLs are attractive because of the simple structure and the suitability for implementation in low-end digital controllers. In this paper, a cascaded SOGI-PLL structure is discussed, with full offset rejection capability. A systematic design procedure is proposed for this PLL minimizing the response time and unit vector harmonic distortion. This design achieves minimum settling time for a given level of frequency deviation of the grid voltage. The PLL designed using the proposed method has sufficient harmonic attenuation capability. The analytical predictions are verified experimentally.
2015-09-27
Technical Paper
2015-28-0003
Arun Karuppaswamy Balasubramanian, Srinivas Gulur, Vinod John
With the increasing use of grid-connected inverters, any improvement in its reliability is desirable. Usual inverter tests focus primarily on thermal testing of semiconductor devices. However, the passive components are also sensitive to temperature. The life of dc bus electrolytic capacitors and output ac filter capacitors are temperature-dependent. Continuous operation of output filter inductors at high temperatures can cause their insulation to fail. Semiconductor thermal test procedures available in literature can be used for thermal testing of passive components also. But, the methods available in literature are regenerative and require the use of additional converters or passive systems of similar rating as the inverter under test for regeneration. A novel thermal test method is proposed for testing of passive components associated with a three-phase two-level grid-connected inverter.
2015-09-27
Technical Paper
2015-28-0004
Ritesh Kumar Keshri, Prabhat Ranjan Tripathi
Estimation of motor torque requires information of motor parameters and becomes crucial to the cases where phase inductance varies with the rotor position. Present paper proposes a simple instantaneous torque estimator for a permanent-magnet brushless dc (PM BLDC) motor drive. Proposed estimator requires information of phase currents from the current sensors and duty ratio applied to the individual phase legs of the VSI. Information of phase inductance is not required. Negligence of phase resistance reduces this estimator to a simplified one with considerable error. Applicability of this estimator even for the sinusoidal phase current supply makes it a general solution for the estimation of instantaneous motor torque for a PM BLDC motor drive. For the validation of the estimator, torque from the Simulink model of PMSM motor with trapezoidal back-emf is considered as a reference.
2015-09-27
Technical Paper
2015-28-0005
Sankar Selvakumar
There are several bidirectional converters are proposed to integrate batteries, ultracapacitors, fuel cell, electric motors, etc., to control the motoring and regenerative breaking effectively in Electrical Vehicle (EV); however, in regenerative breaking the breaking action is much affected because of a) failure of regenerative breaking at lower back emf, and b) discontinuous input current at the motor end. In addition, the traditional BDC are incapable to switch the power flow direction from one to another instantaneously. Therefore, in this paper, we have proposed an instantaneous mode switching bidirectional Boost/SEPIC converter to extract maximum power even under low speed and to switch the power flow direction instantaneously from motoring mode to regenerative breaking mode and vice versa. Finally, the computation results of proposed BDC and traditional BDC are compared.
2015-09-27
Technical Paper
2015-28-0006
V. S. S. Pavan Kumar Hari, Avanish Tripathi, G Narayanan
High-performance industrial drives widely employ induction motors with position sensorless vector control. The speed controller design in such a drive is highly sensitive to the mechanical parameters of the induction motor. This paper proposes a method to determine the mechanical parameters, namely the moment of inertia and frictional coefficient of the induction motor drive. The proposed method is based on acceleration and deceleration of the motor under constant torque, which is achieved using a sensorless vector-controlled drive itself. Experimental results from a $5$hp induction motor drive are presented.
2015-09-27
Technical Paper
2015-28-0007
Anirudh Guha, G Narayanan
Volts-per-hertz (V/f) controlled induction motor drives could exhibit small-signal instability in the low and medium speed range, and particularly under light-load conditions. This results in sustained sub-harmonic oscillations in motor current, torque and speed. This instability is accentuated on account of inverter dead-time. This paper examines improving the stability by connecting an external inductor in series with the stator winding. Further, to avoid an actual external three-phase inductor which could be expensive in the case of high-power drives, a simple control scheme which emulates this series inductor is proposed. This also has the advantage that the value of series inductor could be programmable. This inductive emulation scheme, along with V/f control, is implemented on a TMS320F2812 DSP processor platform to control a 100-kW induction motor drive.
2015-09-27
Technical Paper
2015-28-0008
Mohammad Hassan Hedayati, Vinod John
Ground leakage current and electromagnetic interference (EMI) noise are important challenges during design of grid-connected power converters. Use of common-mode (CM) choke helps to mitigate these issues. In this paper an integrated CM inductor (ICMI) is proposed. In the proposed ICMI, the LCL filter boost inductor and the CM choke are combined into a single component. This results in size and cost reduction of the overall power converter. The proposed ICMI is fabricated in the laboratory. Experimental test are carried out on a 5kW single-phase grid-connected power converter, to validate the effectiveness of the proposed ICMI.
2015-09-27
Technical Paper
2015-28-0010
Amitkumar K. S., G Narayanan
Space vector-based advanced bus-clamping pulse width modulation (ABCWM) techniques for neutral-point clamped three-level converters offer superior performance over conventional space vector pulse width modulation (CSVPWM) and bus-clamping pulse width modulation (BCPWM) under certain operating conditions. However, the digital implementation of ABCPWM methods is quite resource intensive, compared to carrier-based pulse width modulation (PWM) methods. This paper presents a computationally efficient digital implementation of an ABCPWM technique. The ABCPWM method is shown to be advantageous in terms of reduced switching loss at high lagging power factors and reduced harmonic distortion in the inverter output at high modulation indexes.
2015-09-27
Technical Paper
2015-28-0009
Shimin V V, Varsha Shah, Makrand Lokhande
In the current world scenario of increasing environmental issues and oil prices, development of electric vehicles (EV) have gained considerable importance and attention. Power electronics will play a key role in making highly efficient electric vehicles which are low in emissions and having better fuel economy. This paper presents a review of the state of the art of power electronics technology in electric vehicles and also discusses the role of power electronics in achieving the vision of Indian Government in the field of EVs by 2020. The paper concludes with a discussion of expected future trends in power electronics technology that will improve the markets for electric vehicles in coming years.
2015-09-27
Technical Paper
2015-28-0011
Sathiyaraj Asaithambi, Amitabh Vaidya, Riaz Ahamed
Component level validation plays a very important role in an Electric Vehicles during development of a new platform.. Validating the product for their mission life and finding the early failures that can occur in field and correcting the failures at early stages proves to be very helpful in improving product Reliability and confidence. Product durability test is one of the most important tests in validation. Durability testing is the evaluation of duration of time that a product, part, material, or system can meet its performance requirements against its mission life. Durability is conducted on every component, module and also at system and vehicle level. Transmission is commonly used in all the automobile vehicles to transmit power. Transmission in Electric vehicle is a single gear ratio, two stage transmission transmitting power from motor to axle.
2015-09-27
Technical Paper
2015-28-0012
Dheeraj Narang, Subhash Chavadaki
Bicycles were introduced in the 19th century in Europe and now number more than a billion worldwide, twice as many as automobiles. This document gives information about the usage of powered bicycles based on renewable energy systems. The renewable energy which is discussed in this paper is using solar energy. Solar panels are an effective and efficient way of using solar energy. The bicycle uses the solar panels to charge the batteries which intern are used to power a motor, driving the bicycles. It also gives a report on the efficiency of batteries and solar panels. Explanatory material is followed by a worked example.
2015-09-27
Technical Paper
2015-28-0014
Avi Vyas, Amit Kumar, Trapti Katiyar, J P Joshi, Dinesh Singh, Pratik Jain, Himanshu Shah
In this paper, the design methodology and implementation of a digitally controlled, synchronous gate driven and flexible Electronic Power Conditioner (EPC) have been discussed. With incorporation of an FPGA (Field Programmable Gate Array) as its controller, forward topology with active clamp Zero Voltage Switching (ZVS) Technique and synchronous rectification, this dc-dc converter offers flexibility in its output load voltages. Furthermore, each of the output is being sensed and corrected individually through the digital controller in the form of the FPGA. The converter has been designed to cater to the 15W C-band Solid State Power Amplifier (SSPA) at the transmitting section of communication payloads in satellites. These SSPAs have a nominal input power requirement of 45W though the converter has been designed to deliver output power in the range of 20W to 60W.
2015-09-27
Technical Paper
2015-28-0013
Preeti Agarwal, Vineeta Agarwal
For rural or remote areas the single-phase grid has been considered as an alternative especially when compared with the three-phase solution due to its lower cost feature. The loads connected in a three-phase arrangement present some advantages when compared with single-phase loads especially for motors due to their constant torque, constant power, reduced size, etc. High speed machines are used in different applications such as dental drills and medical surgery tools, compressors and turbochargers, blowers, turbo molecular vacuum pumps, compact electrical power suppliers and micro co-generation gas turbines, aircraft electrical starter generator systems, flywheel energy storages and machine tool spindles and electric propulsion systems. This paper proposes a single-phase to three-phase Cycloinverter capable of generating high frequency three-phase output using self-commutated semiconductor devices.
2015-09-27
Technical Paper
2015-28-0016
Srinivas Gulur, Arun Karuppaswamy Balasubramanian, Vinod John
Design of a suitable thermal model inclusive of the enclosure or cabinet, is an integral part of power electronic thermal management. This stems from the fact that power losses in an inverter may cause severe temperature rise in the enclosed cabinet, causing damage to the inverter. The work presents a thermal enclosure model for 3φ, back to back inverter topology rated 24 kVA which is kept in an enclosure having dimensions 1.524 ∗ 1.066 ∗ 1.828 cubic metre. Effects of the inclusion of the thermal enclosure model with the inverter thermal model have been investigated for the above mentioned inverter topology.
2015-09-27
Technical Paper
2015-28-0015
Sachin Singh, Kanwar Pal, Sanjeev Singh
This paper presents a new control scheme for sensorless starting and running of a permanent magnet brushless DC motor (PMBLDCM) while using single current sensor for control of motor torque. The starting is carried out using pulsed starting technique and control is shifted to back EMF sensing method under running condition. The proposed control scheme uses aligning the rotor of PMBLDCM at a known position and then starting the motor by energizing the three phase stator winding through the three phase voltage source inverter (VSI) in a pre defined pulse width modulated (PWM) switching sequence so that the starting current is also controlled within the desired range. After certain speed where the back-EMF is traceable for control of speed, the control is shifted to back-EMF based sensorless operation.
2015-09-27
Technical Paper
2015-28-0018
Abhijit Kulkarni, Vinod John
Inverters with high voltage conversion ratio are used in systems with sources such as batteries, photovoltaic (PV) modules or fuel cells. Transformers are often used in such inverters to provide the required voltage conversion ratio and isolation. In this paper, a compact high-frequency (HF) transformer interfaced AC link inverter is discussed. A high performance synchronized modulation scheme is proposed for this inverter. This modulation addresses the issue of over-voltage spikes due to transformer leakage inductance and achieves better input dc voltage utilization. The problem of spurious turn-on in the HF inverter switches is also mitigated. The performance of the inverter is validated experimentally with the proposed modulation.
2015-09-27
Technical Paper
2015-28-0017
Jiten Chavda, Varsha Shah, Makrand Lokhande, Rakeshkumar Shankar
This paper presents the speed control of sensored BLDC motor using PWM techniques. The BLDC motor with EV or HEV application uses the position sensor for the operation and speed control of motor. In this paper the simulation of BLDC motor is done using soft commutating technique (Proteus Design Suit & Keil uVision3 software). A prototype is implemented to verify the performance of proposed new approach for control of sensored BLDC motor of 48V, 5A, 250W manufactured for E-BIKES. The speed control and real time measurement is obtained and compared and found satisfactory performance.
2015-09-27
Technical Paper
2015-28-0020
Abhishek Shah, Sanjay Phegade
Today the entire world is facing many serious problems namely population explosion, pollution and increasing fuel Prices. Increasing fuel prices is due to the depletion of non-renewable sources of energy, which will adversely affect automotive industry in very near future. Thus it's our responsibility to optimize vehicle fuel economy as much as possible and reduce the CO2 released by the vehicle. This paper focuses on optimizing the electrical energy consumption of vehicle. By introduction three concepts. 1) Innovative speed control logic for radiator & condenser fan motor according to air flow through radiator. 2) Introducing regeneration of energy from radiator and condenser fan motor while free running and deceleration of vehicle. 3) Using AC asynchronous motors (generation and motoring action) in radiator, condenser and blower motors.
2015-09-27
Technical Paper
2015-28-0019
Nimesh Vamanan, Vinod John
Classical control and one cycle control are popular methods to generate gating signals for active device in pwm rectifiers. One cycle control has lower control complexity when compared to classical control. However, in one cycle controlled converters there is a phase lag between fundamental voltage and current, which increases when the converter is loaded. In this paper the reason for phase lag is identified and a novel method to compensate for the same is presented. Effects of grid frequency variation on the degree of compensation is studied. The viability of the proposed compensation is validated using simulation and experimental studies.
2015-09-27
Technical Paper
2015-28-0152
Riaz Ahamed, Koorma Rao Vavilapalli, Abhijit V.P.
The use of 3-Ф Induction Motor with copper rotor for traction applications has been increasing in recent years. Copper die cast rotor has better conductivity than aluminium rotor and its efficiency at higher speeds is almost equivalent to permanent magnet motors. This paper presents the design and analysis of high power density copper rotor electric motor for EV applications. The first step involved in motor design is selection of main dimensions that meet output power requirements. Based on constraints imposed by power and space availability, optimised size of stator frame has been selected for the design. On finalization of main dimensions, stator and rotor slots have been selected; slot dimensions are further optimized to avoid the saturation in tooth and yoke areas of stator and rotor laminations. Higher grade non- oriented steel laminations of lower thickness have been used in stator and rotor to reduce the core losses at higher frequencies.
2015-09-27
Technical Paper
2015-28-0161
Karthikeyan Ethirajan
Rolling resistance contributes ~8% impact on energy efficiency of an automobile. This paper emphasises on how power consumption in an electric vehicle architecture is minimized by reducing rolling resistance through optimization of design parameters in front axle unitised bearing. Optimum bearing design selection can result upto 10% lesser power consumption hence increasing vehicle efficiency. Suitable testing results and calculations establish the claims in reduction of power consumption. The effect of higher energy losses due to rolling resistance are prominent in Electric-Vehicles as compared to IC-Engine cars due to significantly lower power-train losses which overshadow rolling resistance losses in conventional cars.
2015-09-15
Technical Paper
2015-01-2412
Tao Yang, Serhiy Bozhko, Greg Asher
This paper aims to develop a general functional model of multi-pulse Auto-Transformer Rectifier Units (ATRUs) for More-Electric Aircraft (MEA) applications. The ATRU is seen as the most reliable way readily to be applied in the MEA. Interestingly, there is no model of ATRUs suitable for unbalanced or faulty conditions at the moment. This paper is aimed to fill this gap and develop functional models suitable for both balanced and unbalanced conditions. Using the fact that the DC voltage and current are strongly related to the voltage and current vectors at the AC terminals of ATRUs, a generic functional model has been developed for both symmetric and asymmetric ATRUs. The developed functional models are validated through simulation and experiment. The efficiency of the developed model is also demonstrated by comparing with corresponding detailed switching models. The developed functional model shows significant improvement of simulation efficiency, especially under balanced conditions.
2015-04-14
Technical Paper
2015-01-1202
Weimin Zhang, Saeed Anwar, Daniel J. Costinett, Fred Wang
Abstract A cost-effective SiC based hybrid switch and an improved inductor design procedure for boost converter in electric vehicles (EVs) and hybrid electric vehicles (HEVs) are presented in this paper. The feasibility of a hybrid switch using low power SiC MOSFET and high power Si IGBT is investigated to provide a cost-effective and failure-resistant method to employ the fast switching characteristics of SiC devices. The operation of the hybrid switch is tested in double pulse test experiment and compared with the single IGBT. Additionally, the boost inductor design is discussed, which allows the optimization of weight and power loss across different core materials. An improved powder core inductor design procedure is presented to avoid the iterative design procedure provided by the manufacture. Both the powder material and nanocrystalline material are considered in the inductor design procedure.
2015-04-14
Journal Article
2015-01-1201
Mohammad Anwar, Monty Hayes, Anthony Tata, Mehrdad Teimorzadeh, Thomas Achatz
Abstract The Chevrolet Volt is an electric vehicle with extended-range that is capable of operation on battery power alone, and on engine power after depletion of the battery charge. First generation Chevrolet Volts were driven over half a billion miles in North America from October 2013 through September 2014, 74% of which were all-electric [1, 12]. For 2016, GM has developed the second-generation of the Volt vehicle and “Voltec” propulsion system. By significantly re-engineering the traction power inverter module (TPIM) for the second-generation Chevrolet Volt extended-range electric vehicle (EREV), we were able to meet all performance targets while maintaining extremely high reliability and environmental robustness. The power switch was re-designed to achieve efficiency targets and meet thermal challenges. A novel cooling approach enables high power density while maintaining a very high overall conversion efficiency.
2015-04-14
Journal Article
2015-01-1209
Zhengyu Liu, Thomas Winter, Michael Schier
Abstract This paper presents the development of a novel direct coil cooling approach which can enable high performance for electric traction motor, and in further significantly reduce motor losses. The proposed approach focuses on bypassing critical thermal resistances in motor by cooling coils directly in stator slots with oil flow. Firstly, the basic configuration and features are shown: sealed stator slots to air gap, pressure reservoirs on both side of the slots and slot channels for oil flow. The key to enhance thermal performance of the motor here is based on introducing fluid guiding structure in the slot channels. Next, heat transfer in the channel with guiding structure is investigated by CFD and compared with bare slot channel without guiding structure. For studying the effectiveness of proposed cooling concept, numerical analysis is conducted to compare it with HEV favored oil impingement cooling.
2015-04-14
Technical Paper
2015-01-1203
Subhashree Rajagopal, Sebastien Desharnais, Balamurugan Rathinam, Upendra Naithani
Abstract Electromagnetic brakes are found in a variety of applications. They offer tremendous advantages including: absence of fading, high braking torque and controllability. However they suffer from decreasing torque at low and high speeds. In this study, a novel concept of permanent magnet eddy-current brake is proposed that maintains a flat braking torque profile over a broad speed range. The principle is analytically investigated and numerically validated through finite element simulations using MAXWELL. It is demonstrated that a usably flat braking torque profile can be achieved by altering the path of eddy-currents by magnetic field orientation, thereby affecting the apparent rotor resistance.
2014-09-16
Technical Paper
2014-01-2117
Michael L. Zierolf, Thomas Brinson, Andrew Fleming
Abstract Recent emphasis on optimization of engine technologies with ancillary subsystems such as power and thermal management has created a need for integrated system modeling. These systems are coupled such that federated design methods may not lead to the most synergetic solution. Obtaining an optimal design is often contingent on developing an integrated model. Integrated models, however, can involve combining complex simulation platforms into a single system of systems, which can present many challenges. Model organization and configuration control become increasingly important when orchestrating various models into a single simulation. Additionally, it is important to understand such details as the interface between models and signal routing to ensure the integrated behavior is not contaminated or biased. This paper will present some key learnings for model integration to help alleviate some of the challenges with system-based modeling.
2014-09-16
Technical Paper
2014-01-2115
Brian C. Raczkowski, Benjamin Loop, Jason Wells, Eric Walters, Oleg Wasynczuk, Sean Field, Jason Gousy
Abstract Future more electric aircraft (MEA) architectures that improve electrical power system's (EPS's) source and load utilization will require advance stability analysis capabilities. Systems are becoming more complex with bidirectional flows from power regeneration, multiple sources per channel and higher peak to average power ratios. Unknown load profiles with large transients complicate common stability analysis techniques. Advancements in analysis are critical for providing useful feedback to the system integrator and designers of multi-source, multi-load power systems. Overall, a framework for evaluating stability with large displacement events has been developed. Within this framework, voltage transient bounds are obtained by identifying the worst case load profile. The results can be used by system designers or integrators to provide specifications or limits to suppliers. Subsystem suppliers can test and evaluate their design prior to integration and hardware development.
2014-09-16
Technical Paper
2014-01-2113
Fei Gao, Serhiy Bozhko, Greg Asher
Abstract Stability is a great concern for the Electrical Power System (EPS) in the More Electric Aircraft (MEA). It is known that tightly controlled power electronic converters and motor drives may behave as constant power loads (CPLs) which may produce oscillations and cause instability. The paper investigates the stability boundaries for dc multi-source EPS under different power sharing strategies. For each possible strategy the corresponding reduced-order models are derived. The impedance criterion is then applied to study the EPS stability margins and investigates how these margins are influenced by different parameters, such as main bus capacitance, generator/converter control dynamics, cabling arrangements etc. These results are also illustrated by the root contours of reduced-order EPS models. Theoretical results achieved in the paper are confirmed by the time-domain simulations.
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