�ݺ�ߣshows by User: GhazalFalahi

�ݺ�ߣshows by User: GhazalFalahi / http://www.slideshare.net/images/logo.gif �ݺ�ߣshows by User: GhazalFalahi / Sat, 21 May 2016 18:32:42 GMT �ݺ�ߣShare feed for �ݺ�ߣshows by User: GhazalFalahi Performance improvement of parallel active power filters using droop control method /slideshow/performance-improvement-of-parallel-active-power-filters-using-droop-control-method/62260093 performanceimprovementofparallelactivepowerfiltersusingdroopcontrolmethod-160521183242
In this paper, a new method based on droop control scheme is proposed for controlling parallel operation of active filters. The harmonic components of the load current are extracted by an enhanced phase-locked loop (EPLL). In the parallel group, each filter operates as a conductance and the harmonic workload is shared among them. A droop relationship between the conductance and non-fundamental apparent power controls the operation of each unit. The non-fundamental apparent power has been calculated based on IEEE Std 1459. Principles of operation are explained in this paper and simulation results which are presented approve the effectiveness of this method. The results indicate a significant reduction in Total Harmonic Distortion (THD) in a rectifier application.]]>
In this paper, a new method based on droop control scheme is proposed for controlling parallel operation of active filters. The harmonic components of the load current are extracted by an enhanced phase-locked loop (EPLL). In the parallel group, each filter operates as a conductance and the harmonic workload is shared among them. A droop relationship between the conductance and non-fundamental apparent power controls the operation of each unit. The non-fundamental apparent power has been calculated based on IEEE Std 1459. Principles of operation are explained in this paper and simulation results which are presented approve the effectiveness of this method. The results indicate a significant reduction in Total Harmonic Distortion (THD) in a rectifier application.]]> Sat, 21 May 2016 18:32:42 GMT /slideshow/performance-improvement-of-parallel-active-power-filters-using-droop-control-method/62260093 GhazalFalahi@slideshare.net(GhazalFalahi) Performance improvement of parallel active power filters using droop control method GhazalFalahi In this paper, a new method based on droop control scheme is proposed for controlling parallel operation of active filters. The harmonic components of the load current are extracted by an enhanced phase-locked loop (EPLL). In the parallel group, each filter operates as a conductance and the harmonic workload is shared among them. A droop relationship between the conductance and non-fundamental apparent power controls the operation of each unit. The non-fundamental apparent power has been calculated based on IEEE Std 1459. Principles of operation are explained in this paper and simulation results which are presented approve the effectiveness of this method. The results indicate a significant reduction in Total Harmonic Distortion (THD) in a rectifier application. <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/performanceimprovementofparallelactivepowerfiltersusingdroopcontrolmethod-160521183242-thumbnail.jpg?width=120&height=120&fit=bounds" /> In this paper, a new method based on droop control scheme is proposed for controlling parallel operation of active filters. The harmonic components of the load current are extracted by an enhanced phase-locked loop (EPLL). In the parallel group, each filter operates as a conductance and the harmonic workload is shared among them. A droop relationship between the conductance and non-fundamental apparent power controls the operation of each unit. The non-fundamental apparent power has been calculated based on IEEE Std 1459. Principles of operation are explained in this paper and simulation results which are presented approve the effectiveness of this method. The results indicate a significant reduction in Total Harmonic Distortion (THD) in a rectifier application.

Performance improvement of parallel active power filters using droop control method from Ghazal Falahi

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0 Thd minimization of modular multilevel converter with unequal dc values /GhazalFalahi/thd-minimization-of-modular-multilevel-converter-with-unequal-dc-values thdminimizationofmodularmultilevelconverterwithunequaldcvalues-160521183023
Different modulation techniques used to control multilevel converters can be classified based on the selected converter topology and optimization goals. Among all proposed modulation methods low switching frequency modulation techniques are very popular for multilevel converters yet non-real time low switching frequency methods cannot be applied to multilevel converters with unequal or varying DC values because these modulation techniques rely on look up tables and the size of look up tables will be huge in this case. This paper proposes a new modular multilevel converter (MMC) structure with unequal DC values. Some well-known low switching frequency modulation techniques and the commonly used PWM based methods are compared and using the new low switching frequency modulation technique called minimal total harmonic distortion (THD) modulation for MMC with unequal DC values is proposed. The PSCAD simulation results show that the new converter topology with unequal DC values has much lower THD compared to the typical MMC. Modulation algorithm is implemented in digital signal processor (DSP) and controller hardware in the loop (CHIL) implementation in RTDS verifies the real-time performance of the algorithm. ]]>
Different modulation techniques used to control multilevel converters can be classified based on the selected converter topology and optimization goals. Among all proposed modulation methods low switching frequency modulation techniques are very popular for multilevel converters yet non-real time low switching frequency methods cannot be applied to multilevel converters with unequal or varying DC values because these modulation techniques rely on look up tables and the size of look up tables will be huge in this case. This paper proposes a new modular multilevel converter (MMC) structure with unequal DC values. Some well-known low switching frequency modulation techniques and the commonly used PWM based methods are compared and using the new low switching frequency modulation technique called minimal total harmonic distortion (THD) modulation for MMC with unequal DC values is proposed. The PSCAD simulation results show that the new converter topology with unequal DC values has much lower THD compared to the typical MMC. Modulation algorithm is implemented in digital signal processor (DSP) and controller hardware in the loop (CHIL) implementation in RTDS verifies the real-time performance of the algorithm. ]]> Sat, 21 May 2016 18:30:22 GMT /GhazalFalahi/thd-minimization-of-modular-multilevel-converter-with-unequal-dc-values GhazalFalahi@slideshare.net(GhazalFalahi) Thd minimization of modular multilevel converter with unequal dc values GhazalFalahi Different modulation techniques used to control multilevel converters can be classified based on the selected converter topology and optimization goals. Among all proposed modulation methods low switching frequency modulation techniques are very popular for multilevel converters yet non-real time low switching frequency methods cannot be applied to multilevel converters with unequal or varying DC values because these modulation techniques rely on look up tables and the size of look up tables will be huge in this case. This paper proposes a new modular multilevel converter (MMC) structure with unequal DC values. Some well-known low switching frequency modulation techniques and the commonly used PWM based methods are compared and using the new low switching frequency modulation technique called minimal total harmonic distortion (THD) modulation for MMC with unequal DC values is proposed. The PSCAD simulation results show that the new converter topology with unequal DC values has much lower THD compared to the typical MMC. Modulation algorithm is implemented in digital signal processor (DSP) and controller hardware in the loop (CHIL) implementation in RTDS verifies the real-time performance of the algorithm. <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/thdminimizationofmodularmultilevelconverterwithunequaldcvalues-160521183023-thumbnail.jpg?width=120&height=120&fit=bounds" /> Different modulation techniques used to control multilevel converters can be classified based on the selected converter topology and optimization goals. Among all proposed modulation methods low switching frequency modulation techniques are very popular for multilevel converters yet non-real time low switching frequency methods cannot be applied to multilevel converters with unequal or varying DC values because these modulation techniques rely on look up tables and the size of look up tables will be huge in this case. This paper proposes a new modular multilevel converter (MMC) structure with unequal DC values. Some well-known low switching frequency modulation techniques and the commonly used PWM based methods are compared and using the new low switching frequency modulation technique called minimal total harmonic distortion (THD) modulation for MMC with unequal DC values is proposed. The PSCAD simulation results show that the new converter topology with unequal DC values has much lower THD compared to the typical MMC. Modulation algorithm is implemented in digital signal processor (DSP) and controller hardware in the loop (CHIL) implementation in RTDS verifies the real-time performance of the algorithm.

Thd minimization of modular multilevel converter with unequal dc values from Ghazal Falahi

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0 Low voltage ride through control of modular multilevel converter based hvdc systems /slideshow/low-voltage-ride-through-control-of-modular-multilevel-converter-based-hvdc-systems/62260000 lowvoltageridethroughcontrolofmodularmultilevelconverterbasedhvdcsystems-160521182730
Low Voltage Ride Through (LVRT) is an important grid requirement for Voltage Source Converter (VSC) based HVDC links. This paper studies the performance of the modular multilevel converter (MMC) VSC based HVDC systems during faults or voltage dips and proposes a new control strategy to improve the LVRT performance. The proposed algorithm controls the system to generate the required active and reactive powers that are calculated mathematically based on the ratings of the MMC-HVDC system and LVRT requirements. The injected active and reactive power values obey the LVRT guidelines and are adaptable to different grid codes. The mathematical calculations are presented and EMTDC/PSCAD simulation evaluates the performance of the proposed method.]]>
Low Voltage Ride Through (LVRT) is an important grid requirement for Voltage Source Converter (VSC) based HVDC links. This paper studies the performance of the modular multilevel converter (MMC) VSC based HVDC systems during faults or voltage dips and proposes a new control strategy to improve the LVRT performance. The proposed algorithm controls the system to generate the required active and reactive powers that are calculated mathematically based on the ratings of the MMC-HVDC system and LVRT requirements. The injected active and reactive power values obey the LVRT guidelines and are adaptable to different grid codes. The mathematical calculations are presented and EMTDC/PSCAD simulation evaluates the performance of the proposed method.]]> Sat, 21 May 2016 18:27:30 GMT /slideshow/low-voltage-ride-through-control-of-modular-multilevel-converter-based-hvdc-systems/62260000 GhazalFalahi@slideshare.net(GhazalFalahi) Low voltage ride through control of modular multilevel converter based hvdc systems GhazalFalahi Low Voltage Ride Through (LVRT) is an important grid requirement for Voltage Source Converter (VSC) based HVDC links. This paper studies the performance of the modular multilevel converter (MMC) VSC based HVDC systems during faults or voltage dips and proposes a new control strategy to improve the LVRT performance. The proposed algorithm controls the system to generate the required active and reactive powers that are calculated mathematically based on the ratings of the MMC-HVDC system and LVRT requirements. The injected active and reactive power values obey the LVRT guidelines and are adaptable to different grid codes. The mathematical calculations are presented and EMTDC/PSCAD simulation evaluates the performance of the proposed method. <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/lowvoltageridethroughcontrolofmodularmultilevelconverterbasedhvdcsystems-160521182730-thumbnail.jpg?width=120&height=120&fit=bounds" /> Low Voltage Ride Through (LVRT) is an important grid requirement for Voltage Source Converter (VSC) based HVDC links. This paper studies the performance of the modular multilevel converter (MMC) VSC based HVDC systems during faults or voltage dips and proposes a new control strategy to improve the LVRT performance. The proposed algorithm controls the system to generate the required active and reactive powers that are calculated mathematically based on the ratings of the MMC-HVDC system and LVRT requirements. The injected active and reactive power values obey the LVRT guidelines and are adaptable to different grid codes. The mathematical calculations are presented and EMTDC/PSCAD simulation evaluates the performance of the proposed method.

Low voltage ride through control of modular multilevel converter based hvdc systems from Ghazal Falahi

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0 Control of modular multilevel converter based hvdc systems during asymmetrical grid faults /slideshow/control-of-modular-multilevel-converter-based-hvdc-systems-during-asymmetrical-grid-faults/62259944 controlofmodularmultilevelconverterbasedhvdcsystemsduringasymmetricalgridfaults-160521182342
Modular multilevel converter (MMC) is a relatively new and promising topology for HVDC systems. HVDC systems should remain connected during grid faults and isolate the fault. This paper studies the dynamic performance of transformer-less MMC integrated HVDC systems during unbalanced conditions and asymmetrical grid faults. It proposes a new control technique to improve unbalanced system’s performance. The objective of the proposed controller is eliminating negative and zero sequence currents and to improve the overall performance. The controller calculates zero and negative sequence reference voltages and eliminates zero and negative sequence currents without using any current regulator. Therefore the controller is very fast and robust. The effectiveness of the proposed control technique has been validated by EMTDC /PSCAD simulations.]]>
Modular multilevel converter (MMC) is a relatively new and promising topology for HVDC systems. HVDC systems should remain connected during grid faults and isolate the fault. This paper studies the dynamic performance of transformer-less MMC integrated HVDC systems during unbalanced conditions and asymmetrical grid faults. It proposes a new control technique to improve unbalanced system’s performance. The objective of the proposed controller is eliminating negative and zero sequence currents and to improve the overall performance. The controller calculates zero and negative sequence reference voltages and eliminates zero and negative sequence currents without using any current regulator. Therefore the controller is very fast and robust. The effectiveness of the proposed control technique has been validated by EMTDC /PSCAD simulations.]]> Sat, 21 May 2016 18:23:42 GMT /slideshow/control-of-modular-multilevel-converter-based-hvdc-systems-during-asymmetrical-grid-faults/62259944 GhazalFalahi@slideshare.net(GhazalFalahi) Control of modular multilevel converter based hvdc systems during asymmetrical grid faults GhazalFalahi Modular multilevel converter (MMC) is a relatively new and promising topology for HVDC systems. HVDC systems should remain connected during grid faults and isolate the fault. This paper studies the dynamic performance of transformer-less MMC integrated HVDC systems during unbalanced conditions and asymmetrical grid faults. It proposes a new control technique to improve unbalanced system’s performance. The objective of the proposed controller is eliminating negative and zero sequence currents and to improve the overall performance. The controller calculates zero and negative sequence reference voltages and eliminates zero and negative sequence currents without using any current regulator. Therefore the controller is very fast and robust. The effectiveness of the proposed control technique has been validated by EMTDC /PSCAD simulations. <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/controlofmodularmultilevelconverterbasedhvdcsystemsduringasymmetricalgridfaults-160521182342-thumbnail.jpg?width=120&height=120&fit=bounds" /> Modular multilevel converter (MMC) is a relatively new and promising topology for HVDC systems. HVDC systems should remain connected during grid faults and isolate the fault. This paper studies the dynamic performance of transformer-less MMC integrated HVDC systems during unbalanced conditions and asymmetrical grid faults. It proposes a new control technique to improve unbalanced system’s performance. The objective of the proposed controller is eliminating negative and zero sequence currents and to improve the overall performance. The controller calculates zero and negative sequence reference voltages and eliminates zero and negative sequence currents without using any current regulator. Therefore the controller is very fast and robust. The effectiveness of the proposed control technique has been validated by EMTDC /PSCAD simulations.

Control of modular multilevel converter based hvdc systems during asymmetrical grid faults from Ghazal Falahi

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0 Design consideration of an mmc hvdc system based on 4500 v:4000a emitter turn-off (eto) thyristor /slideshow/design-consideration-of-an-mmc-hvdc-system-based-on-4500-v4000a-emitter-turnoff-eto-thyristor/62259894 designconsiderationofanmmc-hvdcsystembasedon4500v4000aemitterturn-offetothyristor-160521182134
Excessive power loss is a major concern in high voltage and high power applications and is considered one of the main drawbacks of VSC-HVDC system when compared with traditional HVDC system based on thyristor technology. This is primarily caused by high switching loss associated with switching devices used in the VSC-HVDC. This issue can be largely addressed by using the emerging MMC-HVDC topology, which requires much lower switching frequency than traditional VSC-HVDC. Emitter turn-off thyristor (ETO) is one of the best high power switching devices packed with many advanced features. ETO thyristor based MMC-HVDC system is therefore an extremely attractive choice for ultra-high voltage and high power HVDCs. This paper discusses the operation principle of ETO based MMC-HVDC as well as its design and loss comparison with other solutions.]]>
Excessive power loss is a major concern in high voltage and high power applications and is considered one of the main drawbacks of VSC-HVDC system when compared with traditional HVDC system based on thyristor technology. This is primarily caused by high switching loss associated with switching devices used in the VSC-HVDC. This issue can be largely addressed by using the emerging MMC-HVDC topology, which requires much lower switching frequency than traditional VSC-HVDC. Emitter turn-off thyristor (ETO) is one of the best high power switching devices packed with many advanced features. ETO thyristor based MMC-HVDC system is therefore an extremely attractive choice for ultra-high voltage and high power HVDCs. This paper discusses the operation principle of ETO based MMC-HVDC as well as its design and loss comparison with other solutions.]]> Sat, 21 May 2016 18:21:34 GMT /slideshow/design-consideration-of-an-mmc-hvdc-system-based-on-4500-v4000a-emitter-turnoff-eto-thyristor/62259894 GhazalFalahi@slideshare.net(GhazalFalahi) Design consideration of an mmc hvdc system based on 4500 v:4000a emitter turn-off (eto) thyristor GhazalFalahi Excessive power loss is a major concern in high voltage and high power applications and is considered one of the main drawbacks of VSC-HVDC system when compared with traditional HVDC system based on thyristor technology. This is primarily caused by high switching loss associated with switching devices used in the VSC-HVDC. This issue can be largely addressed by using the emerging MMC-HVDC topology, which requires much lower switching frequency than traditional VSC-HVDC. Emitter turn-off thyristor (ETO) is one of the best high power switching devices packed with many advanced features. ETO thyristor based MMC-HVDC system is therefore an extremely attractive choice for ultra-high voltage and high power HVDCs. This paper discusses the operation principle of ETO based MMC-HVDC as well as its design and loss comparison with other solutions. <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/designconsiderationofanmmc-hvdcsystembasedon4500v4000aemitterturn-offetothyristor-160521182134-thumbnail.jpg?width=120&height=120&fit=bounds" /> Excessive power loss is a major concern in high voltage and high power applications and is considered one of the main drawbacks of VSC-HVDC system when compared with traditional HVDC system based on thyristor technology. This is primarily caused by high switching loss associated with switching devices used in the VSC-HVDC. This issue can be largely addressed by using the emerging MMC-HVDC topology, which requires much lower switching frequency than traditional VSC-HVDC. Emitter turn-off thyristor (ETO) is one of the best high power switching devices packed with many advanced features. ETO thyristor based MMC-HVDC system is therefore an extremely attractive choice for ultra-high voltage and high power HVDCs. This paper discusses the operation principle of ETO based MMC-HVDC as well as its design and loss comparison with other solutions.

Design consideration of an mmc hvdc system based on 4500 v:4000a emitter turn-off (eto) thyristor from Ghazal Falahi

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0 Design, Modeling and control of modular multilevel converters (MMC) based hvdc systems ghazal falahi /slideshow/design-modeling-and-control-of-modular-multilevel-converters-mmc-based-hvdc-systems-ghazal-falahi/61002555 modelingdesignandcontrolofmodularmultilevelconvertersmmcbasedhvdcsystemsghazalfalahi-160417034029
Modular multilevel converter (MMC) is a relatively new and promising topology, which has gained a lot of interest in industry in the recent years due to its modular design and easy adaption for applications that require different power and voltage level, such as power transmission through HVDC. This presentation investigates the operation of MMC based HVDC systems and proposes new solutions to improve the performance of the system by using new devices and improving the control strategies.]]>
Modular multilevel converter (MMC) is a relatively new and promising topology, which has gained a lot of interest in industry in the recent years due to its modular design and easy adaption for applications that require different power and voltage level, such as power transmission through HVDC. This presentation investigates the operation of MMC based HVDC systems and proposes new solutions to improve the performance of the system by using new devices and improving the control strategies.]]> Sun, 17 Apr 2016 03:40:29 GMT /slideshow/design-modeling-and-control-of-modular-multilevel-converters-mmc-based-hvdc-systems-ghazal-falahi/61002555 GhazalFalahi@slideshare.net(GhazalFalahi) Design, Modeling and control of modular multilevel converters (MMC) based hvdc systems ghazal falahi GhazalFalahi Modular multilevel converter (MMC) is a relatively new and promising topology, which has gained a lot of interest in industry in the recent years due to its modular design and easy adaption for applications that require different power and voltage level, such as power transmission through HVDC. This presentation investigates the operation of MMC based HVDC systems and proposes new solutions to improve the performance of the system by using new devices and improving the control strategies. <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/modelingdesignandcontrolofmodularmultilevelconvertersmmcbasedhvdcsystemsghazalfalahi-160417034029-thumbnail.jpg?width=120&height=120&fit=bounds" /> Modular multilevel converter (MMC) is a relatively new and promising topology, which has gained a lot of interest in industry in the recent years due to its modular design and easy adaption for applications that require different power and voltage level, such as power transmission through HVDC. This presentation investigates the operation of MMC based HVDC systems and proposes new solutions to improve the performance of the system by using new devices and improving the control strategies.

Design, Modeling and control of modular multilevel converters (MMC) based hvdc systems ghazal falahi from Ghazal Falahi

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0 Modular Multilevel Converter MMC tutorial /slideshow/modular-multilevel-converter-mmc-tutorial-61002473/61002473 modularmultilevelconvertermmctutorial-160417033320
A quick tutorial on Modular Multilevel Converter (MMC) structure, operation principal, modulation and control]]>
A quick tutorial on Modular Multilevel Converter (MMC) structure, operation principal, modulation and control]]> Sun, 17 Apr 2016 03:33:20 GMT /slideshow/modular-multilevel-converter-mmc-tutorial-61002473/61002473 GhazalFalahi@slideshare.net(GhazalFalahi) Modular Multilevel Converter MMC tutorial GhazalFalahi A quick tutorial on Modular Multilevel Converter (MMC) structure, operation principal, modulation and control <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/modularmultilevelconvertermmctutorial-160417033320-thumbnail.jpg?width=120&height=120&fit=bounds" /> A quick tutorial on Modular Multilevel Converter (MMC) structure, operation principal, modulation and control

Modular Multilevel Converter MMC tutorial from Ghazal Falahi

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0 https://cdn.slidesharecdn.com/profile-photo-GhazalFalahi-48x48.jpg?cb=1478615438 https://cdn.slidesharecdn.com/ss_thumbnails/performanceimprovementofparallelactivepowerfiltersusingdroopcontrolmethod-160521183242-thumbnail.jpg?width=320&height=320&fit=bounds slideshow/performance-improvement-of-parallel-active-power-filters-using-droop-control-method/62260093 Performance improvemen... https://cdn.slidesharecdn.com/ss_thumbnails/thdminimizationofmodularmultilevelconverterwithunequaldcvalues-160521183023-thumbnail.jpg?width=320&height=320&fit=bounds GhazalFalahi/thd-minimization-of-modular-multilevel-converter-with-unequal-dc-values Thd minimization of mo... https://cdn.slidesharecdn.com/ss_thumbnails/lowvoltageridethroughcontrolofmodularmultilevelconverterbasedhvdcsystems-160521182730-thumbnail.jpg?width=320&height=320&fit=bounds slideshow/low-voltage-ride-through-control-of-modular-multilevel-converter-based-hvdc-systems/62260000 Low voltage ride throu...