EPE Association: NORpie 2004 - Topic 03: PFC & Active Filters

NORpie 2004 - Topic 03: PFC & Active Filters
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > NORpie - Proceedings > NORpie 2004 > NORpie 2004 - Topic 03: PFC & Active Filters

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   Comparison of Series Hybrid Active Power Filter Control Systems in Medium Power Application
By J. Turunen; M. salo; H. Tuusa [View]
[Download]

Abstract: The most common problem in the supply network is current harmonics caused by non-linear loads. The most usual filter types used for harmonic current filtering are passive and active ower filters. However, because of the drawbacks of these filters, new filter types have been researched. These new filter types are based on a combination of passive and active power filters. Hybrid active power filters can be devided into two main categories: series and parallel hybrid active filters. This paper presents the comparison of control systems of three series hybrid active power filters.

   A Current-Source Active Power Filter with a New DC Filter Structure
By M. Salo [View]
[Download]

Abstract: The main drawback of the current-source active power filter is the heavy and bulky dc side filter. The large dc filter is needed to store the energy of the compensated harmonic components. In this paper a new smaller dc filter structure is proposed for the current-source active power filter. In the presented dc filter structure the energy of the most important harmonics are stored in resonant circuit which makes it possible to decrease the overall size of the filter. The function of the proposed dc filter structure is examined with both simulations and experimental tests.

   Evaluation of an Advanced Harmonic Filter for Adjustable Speed Drives using a Toolbox Approach
By L. Asiminoaei; S. Hansen; F. Blaabjerg [View]
[Download]

Abstract: A large diversity of solutions exists to reduce the harmonic emission of the 6-pulse Adjustable Speed Drive in order to fulfill the requirements of the international harmonic standards. Among them, new types of advanced harmonic filters recently gained an increased attention due to their good harmonic reduction performance at the same time with small costs and engineering. In the event that such filters are used to replace existing solutions, the assessment of the harmonic performance before commissioning is a necessity. This assessment is possible by using software tools to compare the performance of different topologies. This paper presents a method to integrate the model of the filter into an existing harmonic calculation toolbox dedicated for harmonic analysis on the 6-pulse converter. The results are linked together into a practical PC software toolbox for harmonic estimation. By using a combination of a pre-stored database and new interpolation techniques the toolbox can provide the harmonic data on real applications allowing comparisons between different mitigation solutions.

   Synchronous Voltage Reversal control of TCSC – impact on SSR conditions
By H. Xie; L. Ängquist [View]
[Download]

Abstract: The paper describes the laboratory setup of a TCSC model. A new control scheme named SVR (Synchronous Voltage Reversal) control is employed instead of the traditional firing angle control scheme. The impact of the SVR controlled TCSC on SSR is investigated in this real-time simulator by analysing the system damping. Some results are presented graphically together with conclusions.

   Dynamic Performance of Current Controllers for Grid-connected Voltage Source Converters under Unbalanced Voltage Conditions
By M. Bongiorno; J. Svensson; A. Sannino [View]
[Download]

Abstract: The increasing use of Voltage Source Converters (VSCs) in grid-connected applications at distribution levels requires control methods that achieve high performance not only during normal operating conditions of the grid, but also under unbalance conditions. These can occur temporarily, due to faults, or permanently, due to uneven distribution of single-phase loads on the three phases of the distribution system. In this paper, three different current controllers for shunt-connected VSC are investigated and compared under unbalanced conditions. The dc-link voltage is constant and steps in the reference currents are applied in order to test the dynamic performance of the system. Simulation and experimental results are shown for all three controllers.

   A Variable Structure Unified Power Flow Controller for Advanced Industrial Applications
By T.-T. Ma [View]
[Download]

Abstract: This paper presents a new application example of flexible ac transmission systems (FACTS) devices in the advanced industrial power control schemes. An integrated multi-functional power quality controller and energy saving system based on the unified power flow controller (UPFC) is proposed. The proposed integrated system can compensate the reactive power, harmonic current and the unbalanced power of the controlled distribution system with a capacity-limitation manner by its shunt branch. It also can regulate multiple load voltages simultaneously based on the prescribed P-V characteristics of distinct loads for the purpose of energy saving via its series branch. The detailed design procedure of the controllers providing flexible hardware configuration and multiple control functions is presented. A 15KVA test-system with the variable structure UPFC configuration performing active power filter functions and simultaneously regulating an 7HP induction motor for energy saving is numerically investigated with EMTP programs. The feasibility and effectiveness of the proposed system and the related control techniques are confirmed through some simulation results.

   Improving the Active Power Filter Performance with a Prediction Based Reference Generation
By M. Routimo; M. Salo; H. Tuusa [View]
[Download]

Abstract: In this paper a current reference generation method for a voltage source shunt active power filter is examined. The proposed method improves the harmonic filtering by compensating the delays in the system. In stationary operating point of the load the method uses measurement data sampled in previous periods to generate a reference prediction. Since in transient state of the load the prediction no longer holds true, a computational control delay compensation algorithm is used in the reference generation instead of the prediction in this situation. Changing the algorithm according to the operating point guarantees effective harmonic compensation in all operating points. In this paper the system performance is examined with an active filter simulation model.

   Design Considerations for optimizing performance & cost of Continuous Mode Boost PFC Circuits
By S. Basu; T. Undeland, [View]
[Download]

Abstract: This paper explores ways, including the use of SiC diodes, to increase the efficiency and switching frequency of Continuous mode Boost PFC Circuits. The dependence of electrical and thermal performances of these PFC circuits on the characteristics of the power switching devices is studied. By making measurements on a practical 1000W PFC circuit prototype, this paper shows as to how every specific application would need a unique design solution to optimize the cost and performance of a PFC circuit.

NORpie 2004 - Topic 03: PFC & Active Filters
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > NORpie - Proceedings > NORpie 2004 > NORpie 2004 - Topic 03: PFC & Active Filters
	[return to parent folder]

	Comparison of Series Hybrid Active Power Filter Control Systems in Medium Power Application By J. Turunen; M. salo; H. Tuusa	[View] [Download]
Abstract: The most common problem in the supply network is current harmonics caused by non-linear loads. The most usual filter types used for harmonic current filtering are passive and active ower filters. However, because of the drawbacks of these filters, new filter types have been researched. These new filter types are based on a combination of passive and active power filters. Hybrid active power filters can be devided into two main categories: series and parallel hybrid active filters. This paper presents the comparison of control systems of three series hybrid active power filters.

	A Current-Source Active Power Filter with a New DC Filter Structure By M. Salo	[View] [Download]
Abstract: The main drawback of the current-source active power filter is the heavy and bulky dc side filter. The large dc filter is needed to store the energy of the compensated harmonic components. In this paper a new smaller dc filter structure is proposed for the current-source active power filter. In the presented dc filter structure the energy of the most important harmonics are stored in resonant circuit which makes it possible to decrease the overall size of the filter. The function of the proposed dc filter structure is examined with both simulations and experimental tests.

	Evaluation of an Advanced Harmonic Filter for Adjustable Speed Drives using a Toolbox Approach By L. Asiminoaei; S. Hansen; F. Blaabjerg	[View] [Download]
Abstract: A large diversity of solutions exists to reduce the harmonic emission of the 6-pulse Adjustable Speed Drive in order to fulfill the requirements of the international harmonic standards. Among them, new types of advanced harmonic filters recently gained an increased attention due to their good harmonic reduction performance at the same time with small costs and engineering. In the event that such filters are used to replace existing solutions, the assessment of the harmonic performance before commissioning is a necessity. This assessment is possible by using software tools to compare the performance of different topologies. This paper presents a method to integrate the model of the filter into an existing harmonic calculation toolbox dedicated for harmonic analysis on the 6-pulse converter. The results are linked together into a practical PC software toolbox for harmonic estimation. By using a combination of a pre-stored database and new interpolation techniques the toolbox can provide the harmonic data on real applications allowing comparisons between different mitigation solutions.

	Synchronous Voltage Reversal control of TCSC – impact on SSR conditions By H. Xie; L. Ängquist	[View] [Download]
Abstract: The paper describes the laboratory setup of a TCSC model. A new control scheme named SVR (Synchronous Voltage Reversal) control is employed instead of the traditional firing angle control scheme. The impact of the SVR controlled TCSC on SSR is investigated in this real-time simulator by analysing the system damping. Some results are presented graphically together with conclusions.

	Dynamic Performance of Current Controllers for Grid-connected Voltage Source Converters under Unbalanced Voltage Conditions By M. Bongiorno; J. Svensson; A. Sannino	[View] [Download]
Abstract: The increasing use of Voltage Source Converters (VSCs) in grid-connected applications at distribution levels requires control methods that achieve high performance not only during normal operating conditions of the grid, but also under unbalance conditions. These can occur temporarily, due to faults, or permanently, due to uneven distribution of single-phase loads on the three phases of the distribution system. In this paper, three different current controllers for shunt-connected VSC are investigated and compared under unbalanced conditions. The dc-link voltage is constant and steps in the reference currents are applied in order to test the dynamic performance of the system. Simulation and experimental results are shown for all three controllers.

	A Variable Structure Unified Power Flow Controller for Advanced Industrial Applications By T.-T. Ma	[View] [Download]
Abstract: This paper presents a new application example of flexible ac transmission systems (FACTS) devices in the advanced industrial power control schemes. An integrated multi-functional power quality controller and energy saving system based on the unified power flow controller (UPFC) is proposed. The proposed integrated system can compensate the reactive power, harmonic current and the unbalanced power of the controlled distribution system with a capacity-limitation manner by its shunt branch. It also can regulate multiple load voltages simultaneously based on the prescribed P-V characteristics of distinct loads for the purpose of energy saving via its series branch. The detailed design procedure of the controllers providing flexible hardware configuration and multiple control functions is presented. A 15KVA test-system with the variable structure UPFC configuration performing active power filter functions and simultaneously regulating an 7HP induction motor for energy saving is numerically investigated with EMTP programs. The feasibility and effectiveness of the proposed system and the related control techniques are confirmed through some simulation results.

	Improving the Active Power Filter Performance with a Prediction Based Reference Generation By M. Routimo; M. Salo; H. Tuusa	[View] [Download]
Abstract: In this paper a current reference generation method for a voltage source shunt active power filter is examined. The proposed method improves the harmonic filtering by compensating the delays in the system. In stationary operating point of the load the method uses measurement data sampled in previous periods to generate a reference prediction. Since in transient state of the load the prediction no longer holds true, a computational control delay compensation algorithm is used in the reference generation instead of the prediction in this situation. Changing the algorithm according to the operating point guarantees effective harmonic compensation in all operating points. In this paper the system performance is examined with an active filter simulation model.

	Design Considerations for optimizing performance & cost of Continuous Mode Boost PFC Circuits By S. Basu; T. Undeland,	[View] [Download]
Abstract: This paper explores ways, including the use of SiC diodes, to increase the efficiency and switching frequency of Continuous mode Boost PFC Circuits. The dependence of electrical and thermal performances of these PFC circuits on the characteristics of the power switching devices is studied. By making measurements on a practical 1000W PFC circuit prototype, this paper shows as to how every specific application would need a unique design solution to optimize the cost and performance of a PFC circuit.