EPE Association: Pelincec 2005 - 14: Dialog I

Pelincec 2005 - 14: Dialog I - Power Quality
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > Pelincec 2005 > Pelincec 2005 - 14: Dialog I - Power Quality

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   Harmonic Compensation Using the Sliding DFT Algorithm for Three-phase Active Power Filter
By Krzysztof Sozanski [View]
[Download]

Abstract: This paper describes the sliding discrete Fourier transform (DFT) algorithm as an alternative for typical DFT used for spectrum analysis and synthesis. As an example a control circuit for a three-phase 75 kVA parallel active power filter (APF) is used. Such filters have been built and tested. Some illustrative, experimental results are also presented in the paper. The control algorithms of the proposed APF are implemented in the fixed-point digital signal processor TMS320C50. The presented control APF algorithm is a good alternative to classical APF control algorithms, because it allows easy selection of control parameters in mains currents: imbalance, reactive power or harmonics contents. In the proposed circuit transient performance of APF is improved using non-causal predictive current compensation.

   The laboratory model of the three phase generator of distorted voltage waveforms.
By Piotr Fabijañski, Andrzej Olszewski, Henryk Supronowicz [View]
[Download]

Abstract: The article consists results of testing the generator distorted voltage waveforms, its static and dynamic features and its implementation using the PC with the converter board DaqBoard2001, the software GEPS and a voltage inverter with a control circuit. In the article are described results of testing the voltage inverter with a current-mode control. The described three-phase generator of distorted voltage waveforms allows changing of amplitude of 1 harm. voltage, changing of displaces voltages (a phase angle), changing of phase frequency between 40–60 Hz, introduction of harmonics (from 2 to 41) and subharmonics in voltages, introduction of sags in voltages, introduction commutation notches in voltages, generating of waves stored by measurement systems.

   Control of Active Power Filter Using DC Bus Voltage
By M. Tarafdar Haque, S. Sarlak, N. Mahboobi [View]
[Download]

Abstract: The shunt active power filter (APF) has proved to be useful device to eliminate current harmonics and to compensate reactive power for linear/nonlinear loads. This paper presents an approach to control the three-phase shunt active power filter. The proposed approach determines the reference currents using the DC side voltage. Simulation results obtained by Matlab and Simulink show that the proposed approach has good performance on compensating of current harmonics, while the load is imbalanced and the source voltages are balanced/imbalanced. In addition, this approach yields a simpler design of the shunt active power filter controller, because of canceling of load currents measurement.

   Control Circuit For Series Active Power Filter Based On Programmable Logic Devices
By Henryk Supronowicz, Andrzej Olszewski, Hubert Gawiñski [View]
[Download]

Abstract: This paper describes a control circuit for the active power filters working with three-phase AC power line. It describes logic circuitries as well as laboratory test results. The control circuit was realized with programmable logic devices and fast analog-to-digital and digital-to-analog converters. Proposed system working with open-loop control, it allows significantly simplifying its logic structure. Programmable logic devices do simultaneously a few independent tasks, so a control algorithm can be performing fast, improving considerably compensation dynamic. This paper includes results of laboratory tests of the active power filter consisted of proposed control circuit and a voltagesource converter.

   Software Development of Active Power Filter Design for Harmonic Mitigation
By Ramdan Emhemmed Rajab, Norman Mariun [View]
[Download]

Abstract: A system called AFDAS (Active Filter Design Aid System) was designed, developed and validated. The main goal of this system is to automate the design process of active power filter using expert system techniques. The system characterized as an intermediate object-oriented system connecting the user with a network of different specialized software packages, without the assumption of the user familiarity with these packages. The implementation includes developing a data base circuits library, generation of formatted files to be used as input streams with the design packages, writing an interface program for each kind of these software’s, and managing the data flow timing and dependency among them. In this paper the circuit topology database development based on PSPICE is presented with examples of single-phase active filter and three-phase active filter both with resistive load.

   Design of a SMES Supported Dynamic Voltage Restorer for Sensitive Loads
By M. Tarafdar Haque, A. Pashaii [View]
[Download]

Abstract: The main purpose of this paper is the presentation of a suitable control method and proper power circuit topology for Dynamic Voltage Restorer (DVR) that uses a Super Magnetic Energy Storage (SMES). The proposed system prevents the voltage sag in distribution networks by injecting the compensation voltage through a series transformer. A chopper, a capacitor and a three-phase rectifier with suitable control strategy are used for energy storage in SMES. The operation of proposed system is verified through analytical analysis and computer simulation results.

   Control strategy for a single phase solution able to improve power quality in DG applications
By Francesco Castelli Dezza, Michele Diforte, Roberto Faranda [View]
[Download]

Abstract: In the last years the technology development has permitted to increase renewable energies utilization and in the same time has contributed to large scale distributed generation applications. Also considering electrical market development the authors evaluate the possibility to provide simple and high performing static converter as interface from the DC font to AC custom load and grid connection. The main contribution of the presented paper is to define a new interface device able, at the same time, to generate active power in the main, and to improve power quality level. Moreover, in the paper is presented an instantaneous strategy control suitable for single phase applications. This generic algorithm control, with proper design of the passive elements, such as the coupling filter to the PCC, permits to generate active and reactive power flow and integrate the active filtering of a generic non linear load.

   A Comparative Study of Stationary Frame and Fixed Switching Frequency Digital Current Control Techniques for Power Active Filters
By Amaia López de Heredia; Haizea Gaztañaga; Ion Etxeberria-Otadui; Seddik Bacha; Raúl Reyero [View]
[Download]

Abstract: In this paper two stationary frame digital current control techniques, the RST/Deadbeat and the Multi-Resonant controller, are analysed and experimentally tested in an active filter application. The RST/Deadbeat controller has been tuned in order to obtain a deadbeat response. The method used to tune the Multi-Resonant controller is based on a frequency response approach that guarantees the stability and robustness of the system. It is well-known that the performance of deadbeat controllers is constrained to the accuracy of the plant model as well as the accuracy of the reference and disturbance predictions. The accuracy of the Multi-Resonant controller is guaranteed as long as the system is stable and the harmonics of the reference and the disturbance coincide with the resonance frequencies of the controller. Theoretically the main advantages of the deadbeat controller are its simplicity and its dynamics. However, in a complex application such as the active filtering the intrinsic delay of the controller is unacceptable and therefore it is necessary to use reference (and eventually disturbance) prediction techniques. The use of these techniques can have a non-negligible effect on the characteristics of the system and can be detrimental for both the dynamics and the simplicity of the system. In this paper two different prediction techniques have been implemented: periodicity and resonant. It is shown that the steady-state performances in both cases are satisfactory and similar to those obtained with the Multi-Resonant controller. Nevertheless, the first of the prediction techniques deteriorates significantly the dynamic performance of the system while the second one increases considerably its complexity, showing that the Multi- Resonant controller is better adapted for this kind of applications than the studied deadbeat controller.

   Predictive Direct Power Control of a Rectifier
By Patrycjusz Antoniewicz [View]
[Download]

Abstract: In this paper, a new control scheme for an active rectifier is presented. Proposed power control method uses a discrete-time model of the rectifier to predict future values of the active and reactive power for all possible voltage vectors. The selection of the switching state is made by a quality function considering the power errors. The switching state that minimizes this function is selected for the next sampling period.

   Using Neural Network for Execution of Programmed Pulse Width Modulation (PPWM) Method
By M. Tarafdar Haque, A. Taheri [View]
[Download]

Abstract: Application of neural networks in execution of programmed pulse width modulation (PPWM) of a voltage source inverter (VSI) is studied in this paper. Using the proposed method it is possible to cancel out the desired harmonics in output of VSI in addition to control the magnitude of fundamental harmonic, continuously. By checking the non-trained values and a performance index, the most appropriate neural network is proposed. It is shown that neural networks may solve the custom difficulties of practical utilization of PPWM such as large size of memory, complex digital circuits and controlling the magnitude of output voltage in a discrete manner.

   Investigation of Pseudo-Active State in Z-Source Inverter
By Erik Schaltz, Octavian Oprea, Lasse Larsen, Z. Chen [View]
[Download]

Abstract: This paper introduces a new operating state of the Z-source inverter denoted the pseudo-active state. The pseudoactive state is a state that may boost the output voltage of the Zsource inverter to a level higher than expected. The influence of the pseudo-active state is investigated and an equation used to design the inductors of the Z-source network is derived so the pseudo-active state may be avoided. Simulations and experimental results verifies the equation.

   Electromagnetic compatibility of fixed installations
By Karel Künzel, Jaroslav Zácek [View]
[Download]

Abstract: The paper deals with the EMC requirements for fixed installations, as they are for the first time determined by the new EMC Directive. The essential protection requirements for apparatus and fixed installation are compared, as well as the different conformity assessment procedures. The attention is focused mainly to the specific EMC problems in the fixed installations, such as the relation between the effect of nonlinear loads current harmonics and the short-circuit ratio in the common connection point, and the resonance risk in the compensated system. Both problems are demonstrated by simulation results. The appropriate approach to the assurance of EMC requirements in fixed installation is summarized in the proposed EMC plan.

   Design and performances of an innovative Universal Power Conditioner with UPS function
By Maria Stefania Carmeli, Francesco Castelli-Dezza, Gabrio Superti-Furga [View]
[Download]

Abstract: The present paper proposes the design criteria and performances of a Universal Power Conditioner based on two shunt VSI separated by an inductance. This not conventional double shunt connection implies a number of advantages with respect to the more conventional shunt-series layout both from sizing and performances points of view. Moreover the proposed configuration implies less power switch losses and does not require bypass switch. Sizing analysis is performed for both sinusoidal balanced and disturbance terms from load and mains. Simulation results are reported.

   Wavelets Transform as a Useful Tool in Power Electronic
By Jan Iwaszkiewicz [View]
[Download]

Abstract: The paper presents an approach to the useful theory concerning the problem of generating high quality AC voltage and current waveforms in multilevel converters. The objective is to describe a novel proposal of AC waveforms synthesis based on applying analytical methods using sets of orthogonal wavelets. The discussion includes a short survey of Haar wavelet and a proposal of output waveforms synthesis based on wavelet transform. The comparison of the proposed method with standard solution is discussed. It has been done by use of such criteria as: average square error and total harmonic distortion (THD).

   Application of Universal Custom Power Conditioner in Distribution Networks
By M. Tarafdar Haque, R. Fathi [View]
[Download]

Abstract: This paper proposes a new simple and fast control strategy for Universal Custom Power Conditioner (UCPC). The UCPC is a combination of one series and two shunt active power filter (APF) with a common DC link. The DC link could be a battery energy storage system (BESS) for uninterruptible power supply (UPS). It is possible to connect dispersed generators or other nets to main supply for active power exchange by UCPC while there are some voltage quality sensitive loads in distribution system. Shunt voltage source converter compensates for reactive power, current harmonics and imbalance currents while series voltage source converter compensates for voltage imbalance and voltage harmonics. The proposed method to perform the above mentioned task is based on combination of instantaneous symmetrical components and PQ theory. The validity of operation of control strategy is studied through simulation results.

   Power Quality Concerns of Unit Commitment of Main Transformers for DC Electrified Urban Railway Systems
By Mehrdad Tarafdar Haque, Farhad Shahnia, Mitra Sarhangzadeh [View]
[Download]

Abstract: The power quality problems of DC electrified urban railway systems are discussed for the unit commitment situations on the main transformers of the traction substations. Utilizing unit commitment and the transformer planning procedure for an electrified traction system which is applied to derive the optimal transformer capacity to meet the annual peak demand and provide reserve for service reliability, minimizes the overall cost of main transformers over the life cycle. On the other hand, some power quality problems are caused or even emphasized due to the natural characteristics of the traction system. The dynamic programming method of unit commitment is done in MATLAB where its results are the input data for the rest of our power quality investigation procedure. The power quality characteristics of the traction system are then studied and verified through the simulation results done with PSCAD/EMTDC software.

Pelincec 2005 - 14: Dialog I - Power Quality
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > Pelincec 2005 > Pelincec 2005 - 14: Dialog I - Power Quality
	[return to parent folder]

	Harmonic Compensation Using the Sliding DFT Algorithm for Three-phase Active Power Filter By Krzysztof Sozanski	[View] [Download]
Abstract: This paper describes the sliding discrete Fourier transform (DFT) algorithm as an alternative for typical DFT used for spectrum analysis and synthesis. As an example a control circuit for a three-phase 75 kVA parallel active power filter (APF) is used. Such filters have been built and tested. Some illustrative, experimental results are also presented in the paper. The control algorithms of the proposed APF are implemented in the fixed-point digital signal processor TMS320C50. The presented control APF algorithm is a good alternative to classical APF control algorithms, because it allows easy selection of control parameters in mains currents: imbalance, reactive power or harmonics contents. In the proposed circuit transient performance of APF is improved using non-causal predictive current compensation.

	The laboratory model of the three phase generator of distorted voltage waveforms. By Piotr Fabijañski, Andrzej Olszewski, Henryk Supronowicz	[View] [Download]
Abstract: The article consists results of testing the generator distorted voltage waveforms, its static and dynamic features and its implementation using the PC with the converter board DaqBoard2001, the software GEPS and a voltage inverter with a control circuit. In the article are described results of testing the voltage inverter with a current-mode control. The described three-phase generator of distorted voltage waveforms allows changing of amplitude of 1 harm. voltage, changing of displaces voltages (a phase angle), changing of phase frequency between 40–60 Hz, introduction of harmonics (from 2 to 41) and subharmonics in voltages, introduction of sags in voltages, introduction commutation notches in voltages, generating of waves stored by measurement systems.

	Control of Active Power Filter Using DC Bus Voltage By M. Tarafdar Haque, S. Sarlak, N. Mahboobi	[View] [Download]
Abstract: The shunt active power filter (APF) has proved to be useful device to eliminate current harmonics and to compensate reactive power for linear/nonlinear loads. This paper presents an approach to control the three-phase shunt active power filter. The proposed approach determines the reference currents using the DC side voltage. Simulation results obtained by Matlab and Simulink show that the proposed approach has good performance on compensating of current harmonics, while the load is imbalanced and the source voltages are balanced/imbalanced. In addition, this approach yields a simpler design of the shunt active power filter controller, because of canceling of load currents measurement.

	Control Circuit For Series Active Power Filter Based On Programmable Logic Devices By Henryk Supronowicz, Andrzej Olszewski, Hubert Gawiñski	[View] [Download]
Abstract: This paper describes a control circuit for the active power filters working with three-phase AC power line. It describes logic circuitries as well as laboratory test results. The control circuit was realized with programmable logic devices and fast analog-to-digital and digital-to-analog converters. Proposed system working with open-loop control, it allows significantly simplifying its logic structure. Programmable logic devices do simultaneously a few independent tasks, so a control algorithm can be performing fast, improving considerably compensation dynamic. This paper includes results of laboratory tests of the active power filter consisted of proposed control circuit and a voltagesource converter.

	Software Development of Active Power Filter Design for Harmonic Mitigation By Ramdan Emhemmed Rajab, Norman Mariun	[View] [Download]
Abstract: A system called AFDAS (Active Filter Design Aid System) was designed, developed and validated. The main goal of this system is to automate the design process of active power filter using expert system techniques. The system characterized as an intermediate object-oriented system connecting the user with a network of different specialized software packages, without the assumption of the user familiarity with these packages. The implementation includes developing a data base circuits library, generation of formatted files to be used as input streams with the design packages, writing an interface program for each kind of these software’s, and managing the data flow timing and dependency among them. In this paper the circuit topology database development based on PSPICE is presented with examples of single-phase active filter and three-phase active filter both with resistive load.

	Design of a SMES Supported Dynamic Voltage Restorer for Sensitive Loads By M. Tarafdar Haque, A. Pashaii	[View] [Download]
Abstract: The main purpose of this paper is the presentation of a suitable control method and proper power circuit topology for Dynamic Voltage Restorer (DVR) that uses a Super Magnetic Energy Storage (SMES). The proposed system prevents the voltage sag in distribution networks by injecting the compensation voltage through a series transformer. A chopper, a capacitor and a three-phase rectifier with suitable control strategy are used for energy storage in SMES. The operation of proposed system is verified through analytical analysis and computer simulation results.

	Control strategy for a single phase solution able to improve power quality in DG applications By Francesco Castelli Dezza, Michele Diforte, Roberto Faranda	[View] [Download]
Abstract: In the last years the technology development has permitted to increase renewable energies utilization and in the same time has contributed to large scale distributed generation applications. Also considering electrical market development the authors evaluate the possibility to provide simple and high performing static converter as interface from the DC font to AC custom load and grid connection. The main contribution of the presented paper is to define a new interface device able, at the same time, to generate active power in the main, and to improve power quality level. Moreover, in the paper is presented an instantaneous strategy control suitable for single phase applications. This generic algorithm control, with proper design of the passive elements, such as the coupling filter to the PCC, permits to generate active and reactive power flow and integrate the active filtering of a generic non linear load.

	A Comparative Study of Stationary Frame and Fixed Switching Frequency Digital Current Control Techniques for Power Active Filters By Amaia López de Heredia; Haizea Gaztañaga; Ion Etxeberria-Otadui; Seddik Bacha; Raúl Reyero	[View] [Download]
Abstract: In this paper two stationary frame digital current control techniques, the RST/Deadbeat and the Multi-Resonant controller, are analysed and experimentally tested in an active filter application. The RST/Deadbeat controller has been tuned in order to obtain a deadbeat response. The method used to tune the Multi-Resonant controller is based on a frequency response approach that guarantees the stability and robustness of the system. It is well-known that the performance of deadbeat controllers is constrained to the accuracy of the plant model as well as the accuracy of the reference and disturbance predictions. The accuracy of the Multi-Resonant controller is guaranteed as long as the system is stable and the harmonics of the reference and the disturbance coincide with the resonance frequencies of the controller. Theoretically the main advantages of the deadbeat controller are its simplicity and its dynamics. However, in a complex application such as the active filtering the intrinsic delay of the controller is unacceptable and therefore it is necessary to use reference (and eventually disturbance) prediction techniques. The use of these techniques can have a non-negligible effect on the characteristics of the system and can be detrimental for both the dynamics and the simplicity of the system. In this paper two different prediction techniques have been implemented: periodicity and resonant. It is shown that the steady-state performances in both cases are satisfactory and similar to those obtained with the Multi-Resonant controller. Nevertheless, the first of the prediction techniques deteriorates significantly the dynamic performance of the system while the second one increases considerably its complexity, showing that the Multi- Resonant controller is better adapted for this kind of applications than the studied deadbeat controller.

	Predictive Direct Power Control of a Rectifier By Patrycjusz Antoniewicz	[View] [Download]
Abstract: In this paper, a new control scheme for an active rectifier is presented. Proposed power control method uses a discrete-time model of the rectifier to predict future values of the active and reactive power for all possible voltage vectors. The selection of the switching state is made by a quality function considering the power errors. The switching state that minimizes this function is selected for the next sampling period.

	Using Neural Network for Execution of Programmed Pulse Width Modulation (PPWM) Method By M. Tarafdar Haque, A. Taheri	[View] [Download]
Abstract: Application of neural networks in execution of programmed pulse width modulation (PPWM) of a voltage source inverter (VSI) is studied in this paper. Using the proposed method it is possible to cancel out the desired harmonics in output of VSI in addition to control the magnitude of fundamental harmonic, continuously. By checking the non-trained values and a performance index, the most appropriate neural network is proposed. It is shown that neural networks may solve the custom difficulties of practical utilization of PPWM such as large size of memory, complex digital circuits and controlling the magnitude of output voltage in a discrete manner.

	Investigation of Pseudo-Active State in Z-Source Inverter By Erik Schaltz, Octavian Oprea, Lasse Larsen, Z. Chen	[View] [Download]
Abstract: This paper introduces a new operating state of the Z-source inverter denoted the pseudo-active state. The pseudoactive state is a state that may boost the output voltage of the Zsource inverter to a level higher than expected. The influence of the pseudo-active state is investigated and an equation used to design the inductors of the Z-source network is derived so the pseudo-active state may be avoided. Simulations and experimental results verifies the equation.

	Electromagnetic compatibility of fixed installations By Karel Künzel, Jaroslav Zácek	[View] [Download]
Abstract: The paper deals with the EMC requirements for fixed installations, as they are for the first time determined by the new EMC Directive. The essential protection requirements for apparatus and fixed installation are compared, as well as the different conformity assessment procedures. The attention is focused mainly to the specific EMC problems in the fixed installations, such as the relation between the effect of nonlinear loads current harmonics and the short-circuit ratio in the common connection point, and the resonance risk in the compensated system. Both problems are demonstrated by simulation results. The appropriate approach to the assurance of EMC requirements in fixed installation is summarized in the proposed EMC plan.

	Design and performances of an innovative Universal Power Conditioner with UPS function By Maria Stefania Carmeli, Francesco Castelli-Dezza, Gabrio Superti-Furga	[View] [Download]
Abstract: The present paper proposes the design criteria and performances of a Universal Power Conditioner based on two shunt VSI separated by an inductance. This not conventional double shunt connection implies a number of advantages with respect to the more conventional shunt-series layout both from sizing and performances points of view. Moreover the proposed configuration implies less power switch losses and does not require bypass switch. Sizing analysis is performed for both sinusoidal balanced and disturbance terms from load and mains. Simulation results are reported.

	Wavelets Transform as a Useful Tool in Power Electronic By Jan Iwaszkiewicz	[View] [Download]
Abstract: The paper presents an approach to the useful theory concerning the problem of generating high quality AC voltage and current waveforms in multilevel converters. The objective is to describe a novel proposal of AC waveforms synthesis based on applying analytical methods using sets of orthogonal wavelets. The discussion includes a short survey of Haar wavelet and a proposal of output waveforms synthesis based on wavelet transform. The comparison of the proposed method with standard solution is discussed. It has been done by use of such criteria as: average square error and total harmonic distortion (THD).

	Application of Universal Custom Power Conditioner in Distribution Networks By M. Tarafdar Haque, R. Fathi	[View] [Download]
Abstract: This paper proposes a new simple and fast control strategy for Universal Custom Power Conditioner (UCPC). The UCPC is a combination of one series and two shunt active power filter (APF) with a common DC link. The DC link could be a battery energy storage system (BESS) for uninterruptible power supply (UPS). It is possible to connect dispersed generators or other nets to main supply for active power exchange by UCPC while there are some voltage quality sensitive loads in distribution system. Shunt voltage source converter compensates for reactive power, current harmonics and imbalance currents while series voltage source converter compensates for voltage imbalance and voltage harmonics. The proposed method to perform the above mentioned task is based on combination of instantaneous symmetrical components and PQ theory. The validity of operation of control strategy is studied through simulation results.

	Power Quality Concerns of Unit Commitment of Main Transformers for DC Electrified Urban Railway Systems By Mehrdad Tarafdar Haque, Farhad Shahnia, Mitra Sarhangzadeh	[View] [Download]
Abstract: The power quality problems of DC electrified urban railway systems are discussed for the unit commitment situations on the main transformers of the traction substations. Utilizing unit commitment and the transformer planning procedure for an electrified traction system which is applied to derive the optimal transformer capacity to meet the annual peak demand and provide reserve for service reliability, minimizes the overall cost of main transformers over the life cycle. On the other hand, some power quality problems are caused or even emphasized due to the natural characteristics of the traction system. The dynamic programming method of unit commitment is done in MATLAB where its results are the input data for the rest of our power quality investigation procedure. The power quality characteristics of the traction system are then studied and verified through the simulation results done with PSCAD/EMTDC software.