F. Blaabjerg | Aalborg University (original) (raw)

Papers by F. Blaabjerg

2011 International Conference on Electrical Machines and Systems, ICEMS 2011, 2011

The electrical energy consumption continues growing and more applications relay on electricity. W... more The electrical energy consumption continues growing and more applications relay on electricity. We can expect that more 60 % of all energy consumption will be converted and used as electricity. Therefore, it is a demand that production, distribution and use of electrical energy are done as efficient as possible. Further, the recent challenges with nuclear power plants are arguing to find more sustainable energy generation solutions. Of many options, two major technologies will play important roles to solve parts of those future challenges. One is to change the electrical power production from conventional, fossil based energy sources to renewable energy sources. Another is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discus trends of the future grid infrastructure as well as the most emerging renewable energy sources, wind energy and photovoltaics. Then main focus is on the power electronics and control technology for wind turbines as they are the largest renewable power contributor, allowing their penetration into a SmartGrid to be even higher in the future.

2012 IEEE Energy Conversion Congress and Exposition, ECCE 2012, 2012

ABSTRACT

Renewable Energy, 2010

This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this... more This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author?? s name. The primary entry includes the coauthors' names, the title of the paper or other item, and its location, ...

IEEE Transactions on Power Electronics, 2014

In order to minimize the effect of the grid harmonic voltages, harmonic compensation is usually a... more In order to minimize the effect of the grid harmonic voltages, harmonic compensation is usually adopted for a gridtied inverter. However, a large variation of the grid inductance challenges the system stability in case a high-order passive filter is used to connect an inverter to the grid. Although in theory, an adaptive controller can solve this problem, but in such case the grid inductance may need to be detected on-line, which will complicate the control system. This paper investigates the relationship between the maximum gain of the controller that still keeps the system stable and the Q-factor for a grid-tied inverter with an RL series or an RC parallel damped high-order power filter. Then, a robust passive damping method for LLCL-filter based grid-tied inverters is proposed, which effectively can suppress the possible resonances even if the grid inductance varies in a wide range. Simulation and experimental results are in good agreement with the theoretical analysis.

IEEE Transactions on Industrial Electronics, 2006

2002 IEEE 33rd Annual IEEE Power Electronics Specialists Conference. Proceedings (Cat. No.02CH37289), 2000

A novel method of direct synchronous pulsewidth modulation (PWM) is disseminated to three-level v... more A novel method of direct synchronous pulsewidth modulation (PWM) is disseminated to three-level voltage source inverters with control algorithms with elimination of the common-mode voltages in three-phase drive systems with PWM. It provides smooth pulses-ratio changing and a quarter-wave symmetry of the voltage waveforms during the whole control range including overmodulation. Continuous, discontinuous and "direct-direct" schemes of synchronous PWM with both algebraic and trigonometric control functions have been analysed and compared. Simulations give the behaviour of the proposed methods and show some advantages of synchronous PWM in comparison with asynchronous at low ratios between the switching frequency and fundamental frequency.

EPE Journal, 2014

ABSTRACT The recent grid integration of Distributed Energy Resources (DER) possibility the format... more ABSTRACT The recent grid integration of Distributed Energy Resources (DER) possibility the formation of intentional islands in the case of a grid fault conditions. For such island formation is required an active agent capable of governing the micro-grid connection state in a safe mode, especially in connection and disconnection transients. This paper focuses on the design of a method oriented to carry out a stable intentional disconnection, and later re-connection, of local grids from the main distribution grid in an intentional way; also under unbalance load condition. Seamless transfer between grid-connected and isolated mode has been achieved in an alpha-beta stationary reference frame with a frequency based synchronization control loop. Simulation and experimental results are provided to verify the proper performance of the proposed solution.

Twentieth Annual IEEE Applied Power Electronics Conference and Exposition, 2005. APEC 2005., 2005

ABSTRACT The static series compensator (SSC) has shown a significant capability to mitigate volta... more ABSTRACT The static series compensator (SSC) has shown a significant capability to mitigate voltage dips, which are the most severe problem to sensitive loads. Also, it has been declared that the function of the SSC can be extended to work as a series active filter. This paper proposes a moving average filter (MAF) to detect the fundamental component of the measured voltages and currents (needed to control the SSC) while using a double vector control algorithm (DVC) to improve the transient performance of the SSC. This is made to accurately control the fundamental voltage component at the load terminals in the case of distorted grid voltage. Furthermore, a selective harmonic compensation strategy is applied to filter out the grid harmonics. The operation of the SSC under distorted utility conditions and voltage dips is discussed. The validity of the proposed controller is verified by experiments, which have been carried out on a 10-kV SSC laboratory setup. Experimental results have shown the ability of the SSC to mitigate voltage dips and harmonics. It is also shown that the proposed controller has improved the transient performance of the SSC even under distorted utility conditions

IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics, 2006

Abstract – This paper proposes a new technique for grid synchronization under unbalanced and dist... more Abstract – This paper proposes a new technique for grid synchronization under unbalanced and distorted conditions, ie, the Dual Second Order Generalised Integrator – Frequency-Locked Loop (DSOGI-FLL). This grid synchronization system results from the application of the ...

2005 European Conference on Power Electronics and Applications, 2005

ABSTRACT This paper describes the evaluation of a new harmonic calculation software. By using a c... more ABSTRACT This paper describes the evaluation of a new harmonic calculation software. By using a combination of a pre-stored database and new interpolation techniques the software can very fast provide the harmonic data on real applications. The harmonic results obtained with this software have acceptable precision even with limited input data. The evaluation concludes here that this approach is very practical compared to other advanced harmonic analysis methods. The results are supported by comparisons of calculations and measurements given in an industrial application

2012 IEEE Energy Conversion Congress and Exposition (ECCE), 2012

The virtual output impedance loop is known as an effective way to enhance the load sharing stabil... more The virtual output impedance loop is known as an effective way to enhance the load sharing stability and quality of droop-controlled parallel inverters. This paper proposes an improved design of virtual output impedance loop for parallel three-phase voltage source inverters. In the approach, a virtual output impedance loop based on the decomposition of inverter output current is developed, where the positive-and negativesequence virtual impedances are synthesized separately. Thus, the negative-sequence circulating current among the parallel inverters can be minimized by using a large negative-sequence virtual resistance even in the case of feeding a balanced threephase load. Furthermore, to adapt to the variety of unbalanced loads, a dynamically-tuned negative-sequence resistance loop is designed, such that a good compromise between the quality of inverter output voltage and the performance of load sharing can be obtained. Finally, laboratory test results of two parallel three-phase voltage source inverters are shown to confirm the validity of the proposed method.

2012 10th International Power & Energy Conference (IPEC), 2012

ABSTRACT

IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012

Abstract The increased penetration of renewable energy systems, like photovoltaic and wind power ... more Abstract The increased penetration of renewable energy systems, like photovoltaic and wind power systems, rises the concern about the power quality and stability of the utility grid. Some regulations for Low Voltage Ride-Through (LVRT) for medium voltage or high voltage applications, are coming into force to guide these grid-connected distributed power generation systems. In order to verify the response of such systems for voltage disturbance, mainly for evaluation of voltage sags/dips, a Voltage Sag Generator (VSG) is needed. This ...

2008 34th Annual Conference of IEEE Industrial Electronics, 2008

This paper presents a new concept for filtering current harmonics in three-phase four-wire networ... more This paper presents a new concept for filtering current harmonics in three-phase four-wire networks. The four-branch star (FBS) filtering topology presented in this work is characterized by a particular layout consisting of single-phase inductances and capacitors. Via this layout, a power filter, with two different and simultaneous resonance frequencies and sequences, is achieved -one frequency for positive-/negativesequence and another one for zero-sequence components. This filter topology can work either as a passive filter or as a hybrid filter. The paper analyzes the proposed topology and derives fundamental concepts about the control of the resulting hybrid power filter. From this analysis, a specific implementation of a three-phase four-wire hybrid power filter is presented as an illustrative application of the filtering topology. An extensive evaluation using simulation and experimental results is conducted in order to verify and validate the good performance of the proposed four-branch star passive/hybrid power filter.

2007 IEEE Industry Applications Annual Meeting, 2007

ABSTRACT

IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting, 1996

This paper proposes a new improved method to describe the power losses in hard-switched IGBT-inve... more This paper proposes a new improved method to describe the power losses in hard-switched IGBT-inverters. The method includes dependency of voltage, current and temperature which enables the user to simulate thermal effects very fast. The model is used on both a PT and NPT IGBT-module including the freewheeling diode. Methods to extract the parameters to the models are proposed and they are verified by measurements and simulation. It is concluded the proposed model can describe the losses in IGBT-inverters accurate and a tool for simulating thermal effects is obtained. 1454 0-7803-3544-9196 $5.00 0 1996 IEEE

37th IEEE Power Electronics Specialists Conference, 2006

Page 1. New Positive-sequence Voltage Detector for Grid Synchronization of Power Converters under... more Page 1. New Positive-sequence Voltage Detector for Grid Synchronization of Power Converters under Faulty Grid Conditions P. Rodríguez , R. Teodorescu , I. Candela , AV Timbus , M. Liserre and F. Blaabjerg Technical University ...

IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics, 2006

Discussion on the physical interpretation of the reactive power Q is the subject of the paper. Th... more Discussion on the physical interpretation of the reactive power Q is the subject of the paper. This power in common physical interpretation used to be associated with energy oscillation between the load and the supply source. The paper demonstrates that such interpretation is not correct. Just the opposite, the interpretation of the reactive power Q as an effect of energy oscillation is one of the major misinterpretations of power phenomena in electrical circuits. The Currents' Physical Components (CPC) power theory is the main theoretical tool used in the discussion presented in this paper.

2011 International Conference on Electrical Machines and Systems, ICEMS 2011, 2011

The electrical energy consumption continues growing and more applications relay on electricity. W... more The electrical energy consumption continues growing and more applications relay on electricity. We can expect that more 60 % of all energy consumption will be converted and used as electricity. Therefore, it is a demand that production, distribution and use of electrical energy are done as efficient as possible. Further, the recent challenges with nuclear power plants are arguing to find more sustainable energy generation solutions. Of many options, two major technologies will play important roles to solve parts of those future challenges. One is to change the electrical power production from conventional, fossil based energy sources to renewable energy sources. Another is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discus trends of the future grid infrastructure as well as the most emerging renewable energy sources, wind energy and photovoltaics. Then main focus is on the power electronics and control technology for wind turbines as they are the largest renewable power contributor, allowing their penetration into a SmartGrid to be even higher in the future.

2012 IEEE Energy Conversion Congress and Exposition, ECCE 2012, 2012

ABSTRACT

Renewable Energy, 2010

This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this... more This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author?? s name. The primary entry includes the coauthors' names, the title of the paper or other item, and its location, ...

IEEE Transactions on Power Electronics, 2014

In order to minimize the effect of the grid harmonic voltages, harmonic compensation is usually a... more In order to minimize the effect of the grid harmonic voltages, harmonic compensation is usually adopted for a gridtied inverter. However, a large variation of the grid inductance challenges the system stability in case a high-order passive filter is used to connect an inverter to the grid. Although in theory, an adaptive controller can solve this problem, but in such case the grid inductance may need to be detected on-line, which will complicate the control system. This paper investigates the relationship between the maximum gain of the controller that still keeps the system stable and the Q-factor for a grid-tied inverter with an RL series or an RC parallel damped high-order power filter. Then, a robust passive damping method for LLCL-filter based grid-tied inverters is proposed, which effectively can suppress the possible resonances even if the grid inductance varies in a wide range. Simulation and experimental results are in good agreement with the theoretical analysis.

IEEE Transactions on Industrial Electronics, 2006

2002 IEEE 33rd Annual IEEE Power Electronics Specialists Conference. Proceedings (Cat. No.02CH37289), 2000

A novel method of direct synchronous pulsewidth modulation (PWM) is disseminated to three-level v... more A novel method of direct synchronous pulsewidth modulation (PWM) is disseminated to three-level voltage source inverters with control algorithms with elimination of the common-mode voltages in three-phase drive systems with PWM. It provides smooth pulses-ratio changing and a quarter-wave symmetry of the voltage waveforms during the whole control range including overmodulation. Continuous, discontinuous and "direct-direct" schemes of synchronous PWM with both algebraic and trigonometric control functions have been analysed and compared. Simulations give the behaviour of the proposed methods and show some advantages of synchronous PWM in comparison with asynchronous at low ratios between the switching frequency and fundamental frequency.

EPE Journal, 2014

ABSTRACT The recent grid integration of Distributed Energy Resources (DER) possibility the format... more ABSTRACT The recent grid integration of Distributed Energy Resources (DER) possibility the formation of intentional islands in the case of a grid fault conditions. For such island formation is required an active agent capable of governing the micro-grid connection state in a safe mode, especially in connection and disconnection transients. This paper focuses on the design of a method oriented to carry out a stable intentional disconnection, and later re-connection, of local grids from the main distribution grid in an intentional way; also under unbalance load condition. Seamless transfer between grid-connected and isolated mode has been achieved in an alpha-beta stationary reference frame with a frequency based synchronization control loop. Simulation and experimental results are provided to verify the proper performance of the proposed solution.

Twentieth Annual IEEE Applied Power Electronics Conference and Exposition, 2005. APEC 2005., 2005

ABSTRACT The static series compensator (SSC) has shown a significant capability to mitigate volta... more ABSTRACT The static series compensator (SSC) has shown a significant capability to mitigate voltage dips, which are the most severe problem to sensitive loads. Also, it has been declared that the function of the SSC can be extended to work as a series active filter. This paper proposes a moving average filter (MAF) to detect the fundamental component of the measured voltages and currents (needed to control the SSC) while using a double vector control algorithm (DVC) to improve the transient performance of the SSC. This is made to accurately control the fundamental voltage component at the load terminals in the case of distorted grid voltage. Furthermore, a selective harmonic compensation strategy is applied to filter out the grid harmonics. The operation of the SSC under distorted utility conditions and voltage dips is discussed. The validity of the proposed controller is verified by experiments, which have been carried out on a 10-kV SSC laboratory setup. Experimental results have shown the ability of the SSC to mitigate voltage dips and harmonics. It is also shown that the proposed controller has improved the transient performance of the SSC even under distorted utility conditions

IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics, 2006

Abstract – This paper proposes a new technique for grid synchronization under unbalanced and dist... more Abstract – This paper proposes a new technique for grid synchronization under unbalanced and distorted conditions, ie, the Dual Second Order Generalised Integrator – Frequency-Locked Loop (DSOGI-FLL). This grid synchronization system results from the application of the ...

2005 European Conference on Power Electronics and Applications, 2005

ABSTRACT This paper describes the evaluation of a new harmonic calculation software. By using a c... more ABSTRACT This paper describes the evaluation of a new harmonic calculation software. By using a combination of a pre-stored database and new interpolation techniques the software can very fast provide the harmonic data on real applications. The harmonic results obtained with this software have acceptable precision even with limited input data. The evaluation concludes here that this approach is very practical compared to other advanced harmonic analysis methods. The results are supported by comparisons of calculations and measurements given in an industrial application

2012 IEEE Energy Conversion Congress and Exposition (ECCE), 2012

The virtual output impedance loop is known as an effective way to enhance the load sharing stabil... more The virtual output impedance loop is known as an effective way to enhance the load sharing stability and quality of droop-controlled parallel inverters. This paper proposes an improved design of virtual output impedance loop for parallel three-phase voltage source inverters. In the approach, a virtual output impedance loop based on the decomposition of inverter output current is developed, where the positive-and negativesequence virtual impedances are synthesized separately. Thus, the negative-sequence circulating current among the parallel inverters can be minimized by using a large negative-sequence virtual resistance even in the case of feeding a balanced threephase load. Furthermore, to adapt to the variety of unbalanced loads, a dynamically-tuned negative-sequence resistance loop is designed, such that a good compromise between the quality of inverter output voltage and the performance of load sharing can be obtained. Finally, laboratory test results of two parallel three-phase voltage source inverters are shown to confirm the validity of the proposed method.

2012 10th International Power & Energy Conference (IPEC), 2012

ABSTRACT

IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012

Abstract The increased penetration of renewable energy systems, like photovoltaic and wind power ... more Abstract The increased penetration of renewable energy systems, like photovoltaic and wind power systems, rises the concern about the power quality and stability of the utility grid. Some regulations for Low Voltage Ride-Through (LVRT) for medium voltage or high voltage applications, are coming into force to guide these grid-connected distributed power generation systems. In order to verify the response of such systems for voltage disturbance, mainly for evaluation of voltage sags/dips, a Voltage Sag Generator (VSG) is needed. This ...

2008 34th Annual Conference of IEEE Industrial Electronics, 2008

This paper presents a new concept for filtering current harmonics in three-phase four-wire networ... more This paper presents a new concept for filtering current harmonics in three-phase four-wire networks. The four-branch star (FBS) filtering topology presented in this work is characterized by a particular layout consisting of single-phase inductances and capacitors. Via this layout, a power filter, with two different and simultaneous resonance frequencies and sequences, is achieved -one frequency for positive-/negativesequence and another one for zero-sequence components. This filter topology can work either as a passive filter or as a hybrid filter. The paper analyzes the proposed topology and derives fundamental concepts about the control of the resulting hybrid power filter. From this analysis, a specific implementation of a three-phase four-wire hybrid power filter is presented as an illustrative application of the filtering topology. An extensive evaluation using simulation and experimental results is conducted in order to verify and validate the good performance of the proposed four-branch star passive/hybrid power filter.

2007 IEEE Industry Applications Annual Meeting, 2007

ABSTRACT

IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting, 1996

This paper proposes a new improved method to describe the power losses in hard-switched IGBT-inve... more This paper proposes a new improved method to describe the power losses in hard-switched IGBT-inverters. The method includes dependency of voltage, current and temperature which enables the user to simulate thermal effects very fast. The model is used on both a PT and NPT IGBT-module including the freewheeling diode. Methods to extract the parameters to the models are proposed and they are verified by measurements and simulation. It is concluded the proposed model can describe the losses in IGBT-inverters accurate and a tool for simulating thermal effects is obtained. 1454 0-7803-3544-9196 $5.00 0 1996 IEEE

37th IEEE Power Electronics Specialists Conference, 2006

Page 1. New Positive-sequence Voltage Detector for Grid Synchronization of Power Converters under... more Page 1. New Positive-sequence Voltage Detector for Grid Synchronization of Power Converters under Faulty Grid Conditions P. Rodríguez , R. Teodorescu , I. Candela , AV Timbus , M. Liserre and F. Blaabjerg Technical University ...

IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics, 2006

Discussion on the physical interpretation of the reactive power Q is the subject of the paper. Th... more Discussion on the physical interpretation of the reactive power Q is the subject of the paper. This power in common physical interpretation used to be associated with energy oscillation between the load and the supply source. The paper demonstrates that such interpretation is not correct. Just the opposite, the interpretation of the reactive power Q as an effect of energy oscillation is one of the major misinterpretations of power phenomena in electrical circuits. The Currents' Physical Components (CPC) power theory is the main theoretical tool used in the discussion presented in this paper.