LOW POWER FIXED HARDWARE ARCHITECTURE IN FUNCTIONAL TESTING USING BIST
[View]
M.Abilash, A.H.Sharief
This project described an on-chip test generation method for functional broadside tests. The hardware was based on application of primary input sequences in order to allow the circuit to produce reachable states. Random primary input sequences were modeled to avoid repeated synchronization and thus yield varied sets of reachable states by implementing a decoder in between circuit and L.F.S.R. Two-pattern tests were obtained by using pairs of consecutive time units of the primary input sequences. The on-chip generation of functional broadside tests required simple hardware and achieved high fault coverage for testable circuits. Further, power can be reduced by using bit swapping LFSR. This technique yields less number of transitions for all pattern generation. Bit-swapping technique is less complex and more reliable to hardware miscommunications.
M.Abilash, A.H.Sharief
This project described an on-chip test generation method for functional broadside tests. The hardware was based on application of primary input sequences in order to allow the circuit to produce reachable states. Random primary input sequences were modeled to avoid repeated synchronization and thus yield varied sets of reachable states by implementing a decoder in between circuit and L.F.S.R. Two-pattern tests were obtained by using pairs of consecutive time units of the primary input sequences. The on-chip generation of functional broadside tests required simple hardware and achieved high fault coverage for testable circuits. Further, power can be reduced by using bit swapping LFSR. This technique yields less number of transitions for all pattern generation. Bit-swapping technique is less complex and more reliable to hardware miscommunications.
A Five-level Inverter topology forInduction Motor Drive with single DC Link [View]
Ramakrishna. Ch, M.Eswar chand
In this paper a five-level inverter topology is proposed for a four pole induction motor drive. This topology has developed by using the advantage of two identical voltage profile winding coils per phase in a four pole induction motor. The identical voltage profile winding coils are disconnected and each part of the winding is fed with two two-level inverters from both sides. There by four two-level inverters are used to generate five voltage levels on induction motor phase windings. All two-level inverters are fed with single DC link with the magnitude 𝐕𝐝𝐜𝟒 (where 𝑽𝒅𝒄 is the dc-bus voltage required for a conventional NPC five-level inverter). Because of the common DC link for all the two-level inverters, common mode currents will find a path through the motor phase windings due to the lack of isolated neutral. To minimise the common mode currents a Sine-Triangle Pulse Width Modulation is used in the proposed topology. There by the first dominant harmonics and triplen harmonics shifted near to the switching frequency, which will have a less impact on the motor phase currents.Since the dominant harmonics are less in the proposed topology, it gives almost sinusoidal output voltage which will improve the efficiency of the drive system. The proposed topology does not require any major design modifications of induction motor. The proposed topology is simulated in MATLAB (Simulink) with sine triangle PWM .
Ramakrishna. Ch, M.Eswar chand
In this paper a five-level inverter topology is proposed for a four pole induction motor drive. This topology has developed by using the advantage of two identical voltage profile winding coils per phase in a four pole induction motor. The identical voltage profile winding coils are disconnected and each part of the winding is fed with two two-level inverters from both sides. There by four two-level inverters are used to generate five voltage levels on induction motor phase windings. All two-level inverters are fed with single DC link with the magnitude 𝐕𝐝𝐜𝟒 (where 𝑽𝒅𝒄 is the dc-bus voltage required for a conventional NPC five-level inverter). Because of the common DC link for all the two-level inverters, common mode currents will find a path through the motor phase windings due to the lack of isolated neutral. To minimise the common mode currents a Sine-Triangle Pulse Width Modulation is used in the proposed topology. There by the first dominant harmonics and triplen harmonics shifted near to the switching frequency, which will have a less impact on the motor phase currents.Since the dominant harmonics are less in the proposed topology, it gives almost sinusoidal output voltage which will improve the efficiency of the drive system. The proposed topology does not require any major design modifications of induction motor. The proposed topology is simulated in MATLAB (Simulink) with sine triangle PWM .
PERFORMANCE ANAYLSIS OF ACTIVE TYPE SFCL TO REDUCE OVER VOLTAGES AND OVER CURRENTS IN DISTRIBUTION NETWORKS WITH DG UNITS [View]
G. Ganesh , M. Sunil Kumar
The introduction of various distributed generated units into the power distribution network has caused the increase in the fault currents magnitudes and induction of over voltages under abnormal conditions. System protection has become increasingly challenging in these systems. Among the countermeasures to solve this problem, the super conducting fault current limiter (SFCL) has been noticed as the promising and feasible solutions. In this paper a voltage compensation type active SFCL is introduced into the distribution network consisting of DG units and its effects are studied through theoretical derivation and simulation. The active SFCL consists of an air-core superconducting transformer and PWM converter. By changing the converters output current the equivalent impedance of active SFCL can be regulated for current limitation and possible voltage suppression. The suppression characteristics of active SFCL at different DG locations and fault positions are studied through MATLAB simulation. The results show that active SFCL suppresses the short circuit currents and over voltages induced by 3phase to ground fault effectively and power system safety and reliability can be improved.
G. Ganesh , M. Sunil Kumar
The introduction of various distributed generated units into the power distribution network has caused the increase in the fault currents magnitudes and induction of over voltages under abnormal conditions. System protection has become increasingly challenging in these systems. Among the countermeasures to solve this problem, the super conducting fault current limiter (SFCL) has been noticed as the promising and feasible solutions. In this paper a voltage compensation type active SFCL is introduced into the distribution network consisting of DG units and its effects are studied through theoretical derivation and simulation. The active SFCL consists of an air-core superconducting transformer and PWM converter. By changing the converters output current the equivalent impedance of active SFCL can be regulated for current limitation and possible voltage suppression. The suppression characteristics of active SFCL at different DG locations and fault positions are studied through MATLAB simulation. The results show that active SFCL suppresses the short circuit currents and over voltages induced by 3phase to ground fault effectively and power system safety and reliability can be improved.
Comparative Analysis, & Modeling Of A Current Balancing Scheme For High-Power Led Lighting Using Single-Switch Ac-Dc Converters For Power Factor And Efficiency Improvement [View]
P Bhaskar, Tajuddin Sayyad, Dr. Abdul Ahad
This paper addresses several issues concerning the analysis, design, modeling, simulation and development of Single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with Transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, Flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modern design trends towards improved performance, these switching Converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.
P Bhaskar, Tajuddin Sayyad, Dr. Abdul Ahad
This paper addresses several issues concerning the analysis, design, modeling, simulation and development of Single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with Transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, Flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modern design trends towards improved performance, these switching Converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.
Improvement Of Power Factor By Voltage Controlled Adjustable Speed PMBLDCM Drive[View]
Miss Rimi Chauhan, Prof. R. A. Pagare
In this paper, a half-bridge DC-DC converter is used as a single-stage power factor correction (PFC) converter for feeding a voltage source inverter (VSI) based permanent magnet brushless DC motor (PMBLDCM) drive. The front end of this PFC converter is a diode bridge rectifier (DBR) fed from single-phase AC mains. The fly-back PFC converter is operated with the current multiplier control and voltage follower control schemes for improvement of power quality (PQ) at ac mains while controlling the operation of PMBLDCMD in wide range of speeds and input AC voltage variation.
Miss Rimi Chauhan, Prof. R. A. Pagare
In this paper, a half-bridge DC-DC converter is used as a single-stage power factor correction (PFC) converter for feeding a voltage source inverter (VSI) based permanent magnet brushless DC motor (PMBLDCM) drive. The front end of this PFC converter is a diode bridge rectifier (DBR) fed from single-phase AC mains. The fly-back PFC converter is operated with the current multiplier control and voltage follower control schemes for improvement of power quality (PQ) at ac mains while controlling the operation of PMBLDCMD in wide range of speeds and input AC voltage variation.
A Novel Fuzzy Control Strategy High-Efficiency Minimum-Torque-Ripple reduction of Three-Phase BLDC Motor Drive[View]
Sk.Hussain, Sadiq Ahmed Khan, Dr. Abdul. A
Brushless DC motors (BLDCM) are widely used for many industrial applications because of their high efficiency, high torque and low volume. This paper proposed an improved Adaptive Fuzzy controller to control speed of BLDCM. This paper provides an overview of performance conventional PI, Fuzzy controller and Adaptive Fuzzy controller. It is difficult to tune the parameters and get satisfied control characteristics by using normal conventional PI controller. As the Adaptive Fuzzy has the ability to satisfied control characteristics and it is easy for computing. The matlab results verify that a Adaptive Fuzzy controller has better control performance than the both Fuzzy controller and conventional PI controller. The modeling, control and simulation of the BLDC motor have been done using the software package MATLAB/SIMULINK.
Sk.Hussain, Sadiq Ahmed Khan, Dr. Abdul. A
Brushless DC motors (BLDCM) are widely used for many industrial applications because of their high efficiency, high torque and low volume. This paper proposed an improved Adaptive Fuzzy controller to control speed of BLDCM. This paper provides an overview of performance conventional PI, Fuzzy controller and Adaptive Fuzzy controller. It is difficult to tune the parameters and get satisfied control characteristics by using normal conventional PI controller. As the Adaptive Fuzzy has the ability to satisfied control characteristics and it is easy for computing. The matlab results verify that a Adaptive Fuzzy controller has better control performance than the both Fuzzy controller and conventional PI controller. The modeling, control and simulation of the BLDC motor have been done using the software package MATLAB/SIMULINK.
A New Combined Bidirectional 84 Pulse (Multi Level + Multi Pulse) Converter With High-Frequency Link[View]
Bhukya Jala, Firoz Ali.Md , Dr. Abdul Ahad
This paper analyzes the structure of an 84-pulse voltage source converter (VSC), assembled by combining one twelve-pulse VSC, in conjunction with an asymmetric single phase seven-level converter plus an injection transformer. With this arrangement, the VSC output's total harmonic distortion in voltages is reduced, allowing it to be used in especial applications or as the basement of flexible A.C. transmission systems (FACTS) devices. The proposed strategy allows savings in the number of employed switches. Simulations and experimental results are provided to show the proposal appropriateness.
Bhukya Jala, Firoz Ali.Md , Dr. Abdul Ahad
This paper analyzes the structure of an 84-pulse voltage source converter (VSC), assembled by combining one twelve-pulse VSC, in conjunction with an asymmetric single phase seven-level converter plus an injection transformer. With this arrangement, the VSC output's total harmonic distortion in voltages is reduced, allowing it to be used in especial applications or as the basement of flexible A.C. transmission systems (FACTS) devices. The proposed strategy allows savings in the number of employed switches. Simulations and experimental results are provided to show the proposal appropriateness.
A New Proposal For Simplified Control Technique Of Dual Open UPQC [View]
MD Nizamuddin, Shareef Shaik, Dr. Abdul Ahad
Power quality (PQ) is very important to certain customers. For this reason, many utilities could sell electrical energy at different prices to their customers, depending on the quality of the delivered electric power. Since most end users are connected to secondary. Currently, the quality of supplied power is important to several customers. Power quality (PQ) is a service and many customers are ready to pay for it. Different from a conventional UPQC, the open UPQC has the series filter controlled as a sinusoidal current source and the shunt filter controlled as a sinusoidal voltage source. Therefore, the pulse width modulation (PWM) controls of the open UPQC deal with a well-known frequency spectrum, since it is controlled using voltage and current sinusoidal references, different from the conventional UPQC that is controlled using non sinusoidal references. In the future, distribution system operators could decide, or could be obliged by authorities, to supply their customers with different PQ levels and at different prices. A new device that can fulfill this role is the OPEN unified power quality conditioner (UPQC), composed of a power-electronic series main unit installed in the medium-voltage/low-voltage (LV) substation, along with several power-electronic shunt units connected close to the end users.
MD Nizamuddin, Shareef Shaik, Dr. Abdul Ahad
Power quality (PQ) is very important to certain customers. For this reason, many utilities could sell electrical energy at different prices to their customers, depending on the quality of the delivered electric power. Since most end users are connected to secondary. Currently, the quality of supplied power is important to several customers. Power quality (PQ) is a service and many customers are ready to pay for it. Different from a conventional UPQC, the open UPQC has the series filter controlled as a sinusoidal current source and the shunt filter controlled as a sinusoidal voltage source. Therefore, the pulse width modulation (PWM) controls of the open UPQC deal with a well-known frequency spectrum, since it is controlled using voltage and current sinusoidal references, different from the conventional UPQC that is controlled using non sinusoidal references. In the future, distribution system operators could decide, or could be obliged by authorities, to supply their customers with different PQ levels and at different prices. A new device that can fulfill this role is the OPEN unified power quality conditioner (UPQC), composed of a power-electronic series main unit installed in the medium-voltage/low-voltage (LV) substation, along with several power-electronic shunt units connected close to the end users.
Comparative Study Of Reducing The Fault Current And Overvoltage In A Distribution System In Autonomous Micro Grids Operation Using PSO UPFC & SFCL[View]
Suguru Veera Ravindra, Ibrahim Shaik, Dr. Abdul Ahad
This paper proposes a new real and reactive power coordination controller for a unified power flow controller (UPFC). The basic control for the UPFC is such that the series converter of the UPFC controls the transmission line near the micro grid real/reactive power flow and the shunt converter of the UPFC controls the UPFC bus voltage/shunt reactive power and the DC link capacitor voltage. In steady state, the real power demand of the series converter is supplied by the shunt converter of the UPFC. To avoid instability/loss of DC link capacitor voltage during transient conditions, a new real power coordination controller has been designed. During the study process, in view of the changes in the locations of the DG units connected to the system, the DG units injection capacities and the fault positions, the active SFCLs current-limiting and over voltage suppressing characteristics are both simulated in MATLAB.A new PSO based reactive power coordination controller has been designed to limit excessive voltage excursions during reactive power transfers. Matlab simulation results have been presented to show the improvement in the performance of the UPFC control with the proposed real power and reactive power coordination controller.
Suguru Veera Ravindra, Ibrahim Shaik, Dr. Abdul Ahad
This paper proposes a new real and reactive power coordination controller for a unified power flow controller (UPFC). The basic control for the UPFC is such that the series converter of the UPFC controls the transmission line near the micro grid real/reactive power flow and the shunt converter of the UPFC controls the UPFC bus voltage/shunt reactive power and the DC link capacitor voltage. In steady state, the real power demand of the series converter is supplied by the shunt converter of the UPFC. To avoid instability/loss of DC link capacitor voltage during transient conditions, a new real power coordination controller has been designed. During the study process, in view of the changes in the locations of the DG units connected to the system, the DG units injection capacities and the fault positions, the active SFCLs current-limiting and over voltage suppressing characteristics are both simulated in MATLAB.A new PSO based reactive power coordination controller has been designed to limit excessive voltage excursions during reactive power transfers. Matlab simulation results have been presented to show the improvement in the performance of the UPFC control with the proposed real power and reactive power coordination controller.
An Advanced Approach Of A Multi Level DVR[View]
Samanthakurthi Suresh Varma, Ibrahim Shaik, Dr. Abdul Ahad
Dynamic Voltage Restorers are utilized to protect sensitive loads from voltage sags and swells which take place in the distribution systems with a multi level inverter. In this paper, a Dynamic Voltage Restorer (DVR) based on hysteresis voltage control is proposed. The DVR is modeled using Simulink Sim Power System Toolbox. Discrete Fourier Transform (DFT) is used to detect the magnitude and phase jump of the voltage sag and swell. The influence of the band of the hysteresis voltage controller on the quality of the load voltage and DVR voltage is studied. The DVR is tested for three phase voltage sag and swell with phase jump to validate the proposed control scheme.
Samanthakurthi Suresh Varma, Ibrahim Shaik, Dr. Abdul Ahad
Dynamic Voltage Restorers are utilized to protect sensitive loads from voltage sags and swells which take place in the distribution systems with a multi level inverter. In this paper, a Dynamic Voltage Restorer (DVR) based on hysteresis voltage control is proposed. The DVR is modeled using Simulink Sim Power System Toolbox. Discrete Fourier Transform (DFT) is used to detect the magnitude and phase jump of the voltage sag and swell. The influence of the band of the hysteresis voltage controller on the quality of the load voltage and DVR voltage is studied. The DVR is tested for three phase voltage sag and swell with phase jump to validate the proposed control scheme.
Enhanced Control of a DFIG-Based Wind-Power Generation System With Series Grid-Side Converter Under Unbalanced Grid Voltage Conditions [View]
Peetha Vishnu Raju, Ibrahim Shaik, Dr. Abdul Ahad
This paper presents an enhanced control method for a doubly fed induction generator (DFIG)-based wind-power generation system with series grid-side converter (SGSC) under unbalanced grid voltage conditions. The behaviors of the DFIG system with SGSC during network unbalance are described. By injecting a series control voltage generated from the SGSC to balance the stator voltage, the adverse effects of voltage unbalance upon the DFIG, such as stator and rotor current unbalances, electromagnetic torque, and power pulsations, can be removed, and then the conventional vector control strategy for the rotor-side converter remains in full force under unbalanced conditions. Meanwhile, three control targets for the parallel grid-side converter (PGSC) are identified, including eliminating the oscillations in the total active power or reactive power, or eliminating negative-sequence current injected to the grid. Furthermore, a precise current reference generation strategy for the PGSC has been proposed for the PGSC to further improve the operation performance of the whole system. Finally, the proposed coordinated control strategy for the DFIG system with SGSC has been validated by the simulation results of a 2-MW-DFIG- based wind turbine with SGSC and experimental results on a laboratory-scale experimental rig under small steady- state grid voltage unbalance.
Peetha Vishnu Raju, Ibrahim Shaik, Dr. Abdul Ahad
This paper presents an enhanced control method for a doubly fed induction generator (DFIG)-based wind-power generation system with series grid-side converter (SGSC) under unbalanced grid voltage conditions. The behaviors of the DFIG system with SGSC during network unbalance are described. By injecting a series control voltage generated from the SGSC to balance the stator voltage, the adverse effects of voltage unbalance upon the DFIG, such as stator and rotor current unbalances, electromagnetic torque, and power pulsations, can be removed, and then the conventional vector control strategy for the rotor-side converter remains in full force under unbalanced conditions. Meanwhile, three control targets for the parallel grid-side converter (PGSC) are identified, including eliminating the oscillations in the total active power or reactive power, or eliminating negative-sequence current injected to the grid. Furthermore, a precise current reference generation strategy for the PGSC has been proposed for the PGSC to further improve the operation performance of the whole system. Finally, the proposed coordinated control strategy for the DFIG system with SGSC has been validated by the simulation results of a 2-MW-DFIG- based wind turbine with SGSC and experimental results on a laboratory-scale experimental rig under small steady- state grid voltage unbalance.
Design & Analysis Of Boost CCM Power Factor Correction Stages Based On Current Rebuilding Concept In Induction Motor [View]
Sk. Zia Ul Huq,Tajuddin Sayyad, Dr. Abdul Ahad
This paper describes the improvement of power factor of an induction motor by using fly back boost CCM power factor corrector. When power factor is improved, automatically energy will be saved A power factor is the goal of any electrical utility company since if the power factor is less than one, they have to supply more current to the user for a given amount of power use. In so doing they occur more line losses. Induction motors are the most widely used electrical motors due to their reliability, low cost and robustness. For industrial and mining applications, 3- phase AC induction motors are the prime movers for the vast majority of machines. It has been estimated that 70% to 80% of all electricity in the world is consumed by these motors. At no load induction motor has very low power factor. It improves at increasing load from no load to full load. Power factor correction is achieved by the addition of fly back boost CCM power factor corrector in parallel with the connected motor circuits and can be applied at the starter, or applied at the switchboard or distribution panel.
Sk. Zia Ul Huq,Tajuddin Sayyad, Dr. Abdul Ahad
This paper describes the improvement of power factor of an induction motor by using fly back boost CCM power factor corrector. When power factor is improved, automatically energy will be saved A power factor is the goal of any electrical utility company since if the power factor is less than one, they have to supply more current to the user for a given amount of power use. In so doing they occur more line losses. Induction motors are the most widely used electrical motors due to their reliability, low cost and robustness. For industrial and mining applications, 3- phase AC induction motors are the prime movers for the vast majority of machines. It has been estimated that 70% to 80% of all electricity in the world is consumed by these motors. At no load induction motor has very low power factor. It improves at increasing load from no load to full load. Power factor correction is achieved by the addition of fly back boost CCM power factor corrector in parallel with the connected motor circuits and can be applied at the starter, or applied at the switchboard or distribution panel.
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