EPE Association: EPE 2007 - Subtopic 06-5 - DS: Converter control, current/voltage control

EPE 2007 - Subtopic 06-5 - DS: Converter control, current/voltage control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2007 - Conference > EPE 2007 - Topic 06: 'Modulation strategies and specific control methods for static converter' > EPE 2007 - Subtopic 06-5 - DS: Converter control, current/voltage control

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   A New Control Method of Single-stage 4-Leg Matrix Converter
By CLARE Jon ; YUE Fan; WHEELER Patrick ; MASON Nick ; EMPRINGHAM Lee [View]
[Download]

Abstract: This paper introduces a single-stage four-leg matrix converter, which can synthesise any desirable three-phase output line-neutral voltage. Indirect space vector modulation is utilised to control the proposed topology. The input and output current/voltage spaces are used separately which allow control over both the output voltage and input current. The experiment results are present to verify the operation of the proposed modulation technique.

   A Robust Control Technique for Parallel Operation of Uninterruptible Power Supply Inverters
By FIGUERES Emilio; GARCERA Gabriel; PASCUAL Marcos; BENAVENT Jose; GONZALEZ-ESPIN Fran [View]
[Download]

Abstract: A robust control technique applied to modular UPS inverters operating in parallel is presented. When compared to conventional PI control, the proposed technique improves the response of the output voltage to load steps and to high distorted output currents, achieving an excellent distribution of currents between modules. The crossover frequency of the different loop gains involved is moderate, so that robustness to variations of the operation point and to tolerances of the output LC filter components values is achieved. Experimental results on a 1 kVA modular UPS system confirm the viability of the proposed scheme.

   A simple indirect voltage sensing method for line-connected inverters
By WEIGOLD Joerg; BRAUN Michael; BECKER Frank; SCHERER Alexander [View]
[Download]

Abstract: Inverter-fed drives will be used more and more frequently for variable speed drive applications with high dynamics. For saving braking energy and reduction of cooling effort it is useful to deploy self-commutated line side converters even in low power applications. The method proposed in this paper allows to synchronise the converter to the grid without sensing the line voltage. Hence additional hardware for voltage sensing is not necessary. Furthermore the implementation of this method on a microcontroller system is presented.

   Active Damping of LCL Resonance with Minimum Sensor Effort by Means of a Digital Infinite Impulse Response Filter
By ROSEKEIT Martin; DE DONCKER Rik W.; DICK Christian; RICHTER Sebastian; ROLINK Johannes [View]
[Download]

Abstract: This paper presents a concept for active damping of an LCL filter connecting a digitally controlled PWM converter to the grid. Active damping is performed by means of a digital Infinite Impulse Response (IIR) filter. Digital filters, being well known in digital signal analysis, can easily be implemented when using digital controllers and require very low computational effort. In contrast to active damping solutions found in literature, no extra quantities except the controlled current must be sensed. This functionality is proven via experimental results. After a short introduction of the problem and an overview of solutions found in literature, the implemented fundamental procedure for active damping is described. Subsequently, the main idea of using an IIR filter for active damping, being an approximation to a derivative function, is qualified and the design procedure is presented. In this paper it is stated that with this method the sensors are minimized and that due to the approximation of the derivative function the damping performance is lower compared to solutions found in literature. However, the damping effect by using an IIR filter is proven. The use of IIR filters and the reduction of sensor effort for active damping of EMI filters with multiple passives looks promising also for other applications with a known load.

   Application of Multiple integrator based controllers for low switching frequency Multilevel NPC Power Active Filters: limitations and improved structures
By ABAD Gonzalo; LOPEZ DE HEREDIA Amaia; RODRIGUEZ Miguel Angel; BACHA Seddik; AURTENECHEA Sergio; ETXEBERRIA-OTADUI Ion [View]
[Download]

Abstract: In digitally controlled high power applications switching frequency restrictions may degrade considerably the closed-loop frequency response of the control structure, introducing important and hazardous resonance bands. In this paper this phenomenon is demonstrated on the base of a conventional multi-integrator based controller and various improving methods are proposed and analyzed (both in simulation and experimentally).

   Comparison of 3D-SVPWM and Carrier-Based Pwm of Three-Phase Four-Leg Voltage Source Inverter for Power Supply Units
By PEROUTKA Zdenek; MOLNAR Jan; GLASBERGER Tomas [View]
[Download]

Abstract: This paper deals with design of a new control system for a diesel-electric power supply unit, which output part is composed of a three-phase four-leg voltage source inverter. The main emphasis is given in this paper on employed modulation techniques. We are introducing two modulation strategies: 1) threedimensional space vector PWM (3D-SVPWM) and 2) improved carrier-based PWM (CBPWM), which employs control of voltage offset via control of the fourth inverter leg. Further, control algorithms enabling operation of the supply unit under arbitrary load conditions (linear, non-linear, symmetrical, unsymmetrical etc.) in any case with sinusoidal voltages at the converter output are described. Behaviour of the designed control system with both 3D-SVPWM and CBPWM strategies has been verified on a laboratory prototype of the power supply unit with rated power of 18kVA.

   Compensation of Output Voltage Distortion Analysis of PWM Inverter with LC Filter Caused by Device Voltage Drop
By FUNATO Hirohito; OGASAWARA Satoshi; NAKAMURA Yuusuke [View]
[Download]

Abstract: The objective of this paper is analysis of output voltage distortion of a PWM inverter with LC filter caused by device voltage drop. The goal of this study is to find out how to compensate the output voltage distortion of PWM inverter caused by device voltage drop to realize precise output voltage. The output voltage distortion is mainly caused by dead time and device voltage drop. There are a lot of studies about distortion is mainly caused by dead time[2]. There are, however, only few studies about device voltage drop. especially considering LC filter effect. In this paper, the authors theoretically derived the output voltage distortion of PWM inverter with LC filter caused by device voltage drop in order to estimate the distortion caused by drop in advance. The distortion was analyzed from the view point of frequency analysis and Total Harmonic Distortion(THD). These results may allow appropriate design of PWM inverter with output voltage compensation. Theoretical analysis was verified through simulations and experiments. In addition, a simple method for compensation of device voltage drop proposed. The proposed method was verified through simulation.

   CRA Based Robust Digital Controller for a Single Phase UPS Inverter
By CHOI Jaeho; LEE Jinmok; PARK Gawoo [View]
[Download]

Abstract: This paper proposes a robust digital controller for PWM voltage source inverter using CRA method. The usual inverter controller for the operation of constant voltage and constant frequency consists of a double looped PI controller for the outer voltage controller and the inner current controller, of which the order of characteristic polynomial is high and so the gain tuning is difficult. Considering the limited switching frequency of the devices and sampling frequency of the digital controller, the gain tuning is usually based on the engineering experiences with the try and error method. In this paper, the error-space approach is used to get the system model including the controller with low order, and the characteristic ratio assignment (CRA) method is proposed for the design of robust controller which has the advantage to design the optimal gain to meet the referenced response and overshoot within the limit range. The PSiM simulation and experience results are shown to verify the validity of the proposed controller.

   DC-link Voltage Balancing Algorithm Using a Space-Vector Hysteresis Current Control for Three-level VSI Applied for Wind Conversion System
By BERKOUK Ebdelmadjid; FRANCOIS Bruno; GHENNAM Tarak [View]
[Download]

Abstract: One of the most inherent problems of the multi-level NPC topology is to maintain the neutral point voltage in a narrow band around the half of the DC voltage. This paper presents a DC-link voltage balancing algorithm for three-level voltage source inverter using a new space-vector based on hysteresis current control (SV-HCC). The proposed SV-HCC controls the active and reactive power delivered to the grid by the doubly fed induction generator (DFIG) by means of controlling its rotor currents. In addition, it controls the neutral point voltage using the redundant inverter switching states. Simple look-up tables are required for areas and sectors detection and also for vectors selection. The performance of the proposed control technique has been verified by simulation.

   Digital compensation of a high-frequency voltage-mode dc-dc converter
By CHANG Wei-Hsu; HSIA Tsun-Hsiao; LIN Yu-Zheng; CHEN Dan; TSAI Hsien-Yi [View]
[Download]

Abstract: This paper explores the potential and the pitfall of digital compensation in a voltage-mode dc-dc converter. A FPGA-based synchronous DC-DC buck converter was used to implement the proposed two digital compensating schemes. One was to use a pair of complex compensating zeros and the other was to use a positive pole. Small-signal models of converters with digital control will be used to illustrate some basic concepts. Complex-zero compensation may improve the control loop gain characteristics but positive-pole compensation is infeasible

   Digital Control of a Three-Phase Four-Leg Inverter under Unbalanced Voltage Conditions
By CUREA Octavian; VILLATE MARTINEZ Jose Luis; CAMBLONG Haritza; VECHIU Ionel; CEBALLOS Salva [View]
[Download]

Abstract: In this paper, the implementation of an innovative inverter control strategy based on the symmetrical components is presented. Symmetrical components of the inverter output voltage and current are decomposed into dq DC quantities to control a three-phase four-leg inverter. This kind of inverter can be a good choice for the applications with hybrid power system based on renewable energy used to supply unbalanced loads. The addition of a fourth leg provides an extra degree of freedom, making possible to handle the neutral current caused by the unbalanced load. Simulation results are compared with experimental results for a prototype inverter to verify the validity of the proposed control strategy.

   Dual-Inductive Snubber Circuit Design for Three-Level Inverter
By ALNASSEIR Jamal; HEROLD Gerhard; WEINDL Christian [View]
[Download]

Abstract: A new circuit design for the protection of e.g. multi level converters will be presented in this paper. The so-called "dual-inductive snubber circuit design for three-level converter" will optimize the number of the total snubber circuit elements and the behavior RCD/ RLD snubber circuit especially in the direction of over-voltage and over-current, and will be suitable to be used in high power inverters as well as FACTS systems due to its features. The new design comprises most of the advantages of the common snubber circuit as a low number of components, improved efficiency and power semiconductor losses due to the low number of snubber elements, reduced over-voltage across the semiconductor devices and no balancing problems. The presented snubber circuit has been analyzed, compared, and confronted to the output of a standardized three level converter system to verify its advantages.

   FPGA based Sequential Switching control strategy for a Three Phase Inverter
By JEZERNIK Karel; POLIC Ales [View]
[Download]

Abstract: This paper introduces a new sequential switching control strategy for a current control of a three phase inverter. The key idea, presented in this paper, is to integrate the benefits of the variable structure system control design and the event-driven sequential control structures to raise the system performance and to improve the control efficiency. Twofold design covers the switching conditions determination using the Lyapunov stability criteria and the event-driven sequential switching pattern design for the switching of inverter transistors. The proposed control design is applied for the control of three phase permanent magnet synchronous machine.

   FPGA-based Vector PI Regulator for Electrical Drives Control
By MONMASSON Eric; ABDELLATIF Meriem; SLAMA-BELKHODJA Ilhem; NAOUAR Wissem [View]
[Download]

Abstract: This work presents the design of the hardware architecture of an optimized and reusable Vector PI (VPI) Regulator, which is implemented on a Field Programmable Gate Array (FPGA) target. It is especially dedicated for FPGA-based vector controls of AC drives, where two or more PI current regulators are required at the same time. So, using only one optimized VPI regulator instead of two optimized PI regulators is more advantageous, since it leads to a less consumption of the FPGA hardware resources. The developed VPI hardware architecture is tested through the FPGA implementation of a classical vector current controller, which is used for the current control of a three phase RL load. Experimental results carried on a prototyping platform are presented in order to illustrate the efficiency of the developed VPI hardware architecture.

   Output Voltage Distortion Compensation for Half-Bridge Inverters
By CHEN Yaow-Ming [View]
[Download]

Abstract: This paper proposes a new control strategy for the half-bridge inverter with a compensation circuit to compensate the output voltage distortion caused by the voltage unbalance of the series connected input capacitors. It can extend the operation range of the half-bridge inverter without sacrificing the output power quality. The compensation circuit is activated only when the output voltage distortion occurs. The operation principle and control flowchart of the proposed compensation strategy are introduced. Hardware experimental results with different operation conditions are presented to verify the validity of the proposed compensation strategy.

   Predictive Direct Power Control of MV-Grid-connected Two-Level and Three-Level NPC Converters: Experimental Results
By AURTENECHEA Sergio; RODRIGUEZ Miguel [View]
[Download]

Abstract: This paper deals with the Predictive Direct Power Control of MV-grid-connected two-level and three-level NPC converters. The well-known direct power control is combined with a predictive selection of a voltage-vectors sequence, obtaining both high transient dynamic and constant switching frequency on high-power converters. The initial Predictive Direct Power Control proposal explored only the basic formulation based on simple vector-sequences applied to two-level converters. Later on, the same approach was extended to the family of three-level NPC converters, including the predictive direct control of neural voltage. In the same way, an advanced hybrid Predictive Direct Power Control was presented, providing only simulated data. The work presented in this paper provides experimental results of the hybrid Predictive Direct Power Control applied to two-level and three-level NPC converters. These results show that the P-DPC approach is an attractive solution to MV grid-connected applications.

   PWM Rectifier with LCL-Filter using different Current Control Structures
By DANNEHL Joerg; FUCHS Friedrich W.; HANSEN Steffan [View]
[Download]

Abstract: The control of a PWM rectifier with LCL-filter using a minimum number of sensors is analyzed. In addition to the DC-link voltage either the converter or line current is measured. Two different ways of current control are shown, analyzed and compared by simulations as well as experimental investigations. Main focus is spent on active damping of the LCL filter resonance and on robustness against line inductance variations.

   Three-Phase Inverter with Output LC Filter Using Predictive Control for UPS Applications
By CORTES Patricio; RODRIGUEZ Jose [View]
[Download]

Abstract: The use of an inverter with an output LC filter allows for generation of sinusoidal voltages with low harmonic distortion. However, the controller design becomes more difficult. This paper presents a new and simple control scheme using predictive control. The controller uses a model of the system to predict, on each sampling interval, the behavior of the output voltage for each possible switching state, then a cost function is used as a criterion for selecting the switching state that will be applied during the next sampling interval.

EPE 2007 - Subtopic 06-5 - DS: Converter control, current/voltage control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2007 - Conference > EPE 2007 - Topic 06: 'Modulation strategies and specific control methods for static converter' > EPE 2007 - Subtopic 06-5 - DS: Converter control, current/voltage control
	[return to parent folder]

	A New Control Method of Single-stage 4-Leg Matrix Converter By CLARE Jon ; YUE Fan; WHEELER Patrick ; MASON Nick ; EMPRINGHAM Lee	[View] [Download]
Abstract: This paper introduces a single-stage four-leg matrix converter, which can synthesise any desirable three-phase output line-neutral voltage. Indirect space vector modulation is utilised to control the proposed topology. The input and output current/voltage spaces are used separately which allow control over both the output voltage and input current. The experiment results are present to verify the operation of the proposed modulation technique.

	A Robust Control Technique for Parallel Operation of Uninterruptible Power Supply Inverters By FIGUERES Emilio; GARCERA Gabriel; PASCUAL Marcos; BENAVENT Jose; GONZALEZ-ESPIN Fran	[View] [Download]
Abstract: A robust control technique applied to modular UPS inverters operating in parallel is presented. When compared to conventional PI control, the proposed technique improves the response of the output voltage to load steps and to high distorted output currents, achieving an excellent distribution of currents between modules. The crossover frequency of the different loop gains involved is moderate, so that robustness to variations of the operation point and to tolerances of the output LC filter components values is achieved. Experimental results on a 1 kVA modular UPS system confirm the viability of the proposed scheme.

	A simple indirect voltage sensing method for line-connected inverters By WEIGOLD Joerg; BRAUN Michael; BECKER Frank; SCHERER Alexander	[View] [Download]
Abstract: Inverter-fed drives will be used more and more frequently for variable speed drive applications with high dynamics. For saving braking energy and reduction of cooling effort it is useful to deploy self-commutated line side converters even in low power applications. The method proposed in this paper allows to synchronise the converter to the grid without sensing the line voltage. Hence additional hardware for voltage sensing is not necessary. Furthermore the implementation of this method on a microcontroller system is presented.

	Active Damping of LCL Resonance with Minimum Sensor Effort by Means of a Digital Infinite Impulse Response Filter By ROSEKEIT Martin; DE DONCKER Rik W.; DICK Christian; RICHTER Sebastian; ROLINK Johannes	[View] [Download]
Abstract: This paper presents a concept for active damping of an LCL filter connecting a digitally controlled PWM converter to the grid. Active damping is performed by means of a digital Infinite Impulse Response (IIR) filter. Digital filters, being well known in digital signal analysis, can easily be implemented when using digital controllers and require very low computational effort. In contrast to active damping solutions found in literature, no extra quantities except the controlled current must be sensed. This functionality is proven via experimental results. After a short introduction of the problem and an overview of solutions found in literature, the implemented fundamental procedure for active damping is described. Subsequently, the main idea of using an IIR filter for active damping, being an approximation to a derivative function, is qualified and the design procedure is presented. In this paper it is stated that with this method the sensors are minimized and that due to the approximation of the derivative function the damping performance is lower compared to solutions found in literature. However, the damping effect by using an IIR filter is proven. The use of IIR filters and the reduction of sensor effort for active damping of EMI filters with multiple passives looks promising also for other applications with a known load.

	Application of Multiple integrator based controllers for low switching frequency Multilevel NPC Power Active Filters: limitations and improved structures By ABAD Gonzalo; LOPEZ DE HEREDIA Amaia; RODRIGUEZ Miguel Angel; BACHA Seddik; AURTENECHEA Sergio; ETXEBERRIA-OTADUI Ion	[View] [Download]
Abstract: In digitally controlled high power applications switching frequency restrictions may degrade considerably the closed-loop frequency response of the control structure, introducing important and hazardous resonance bands. In this paper this phenomenon is demonstrated on the base of a conventional multi-integrator based controller and various improving methods are proposed and analyzed (both in simulation and experimentally).

	Comparison of 3D-SVPWM and Carrier-Based Pwm of Three-Phase Four-Leg Voltage Source Inverter for Power Supply Units By PEROUTKA Zdenek; MOLNAR Jan; GLASBERGER Tomas	[View] [Download]
Abstract: This paper deals with design of a new control system for a diesel-electric power supply unit, which output part is composed of a three-phase four-leg voltage source inverter. The main emphasis is given in this paper on employed modulation techniques. We are introducing two modulation strategies: 1) threedimensional space vector PWM (3D-SVPWM) and 2) improved carrier-based PWM (CBPWM), which employs control of voltage offset via control of the fourth inverter leg. Further, control algorithms enabling operation of the supply unit under arbitrary load conditions (linear, non-linear, symmetrical, unsymmetrical etc.) in any case with sinusoidal voltages at the converter output are described. Behaviour of the designed control system with both 3D-SVPWM and CBPWM strategies has been verified on a laboratory prototype of the power supply unit with rated power of 18kVA.

	Compensation of Output Voltage Distortion Analysis of PWM Inverter with LC Filter Caused by Device Voltage Drop By FUNATO Hirohito; OGASAWARA Satoshi; NAKAMURA Yuusuke	[View] [Download]
Abstract: The objective of this paper is analysis of output voltage distortion of a PWM inverter with LC filter caused by device voltage drop. The goal of this study is to find out how to compensate the output voltage distortion of PWM inverter caused by device voltage drop to realize precise output voltage. The output voltage distortion is mainly caused by dead time and device voltage drop. There are a lot of studies about distortion is mainly caused by dead time[2]. There are, however, only few studies about device voltage drop. especially considering LC filter effect. In this paper, the authors theoretically derived the output voltage distortion of PWM inverter with LC filter caused by device voltage drop in order to estimate the distortion caused by drop in advance. The distortion was analyzed from the view point of frequency analysis and Total Harmonic Distortion(THD). These results may allow appropriate design of PWM inverter with output voltage compensation. Theoretical analysis was verified through simulations and experiments. In addition, a simple method for compensation of device voltage drop proposed. The proposed method was verified through simulation.

	CRA Based Robust Digital Controller for a Single Phase UPS Inverter By CHOI Jaeho; LEE Jinmok; PARK Gawoo	[View] [Download]
Abstract: This paper proposes a robust digital controller for PWM voltage source inverter using CRA method. The usual inverter controller for the operation of constant voltage and constant frequency consists of a double looped PI controller for the outer voltage controller and the inner current controller, of which the order of characteristic polynomial is high and so the gain tuning is difficult. Considering the limited switching frequency of the devices and sampling frequency of the digital controller, the gain tuning is usually based on the engineering experiences with the try and error method. In this paper, the error-space approach is used to get the system model including the controller with low order, and the characteristic ratio assignment (CRA) method is proposed for the design of robust controller which has the advantage to design the optimal gain to meet the referenced response and overshoot within the limit range. The PSiM simulation and experience results are shown to verify the validity of the proposed controller.

	DC-link Voltage Balancing Algorithm Using a Space-Vector Hysteresis Current Control for Three-level VSI Applied for Wind Conversion System By BERKOUK Ebdelmadjid; FRANCOIS Bruno; GHENNAM Tarak	[View] [Download]
Abstract: One of the most inherent problems of the multi-level NPC topology is to maintain the neutral point voltage in a narrow band around the half of the DC voltage. This paper presents a DC-link voltage balancing algorithm for three-level voltage source inverter using a new space-vector based on hysteresis current control (SV-HCC). The proposed SV-HCC controls the active and reactive power delivered to the grid by the doubly fed induction generator (DFIG) by means of controlling its rotor currents. In addition, it controls the neutral point voltage using the redundant inverter switching states. Simple look-up tables are required for areas and sectors detection and also for vectors selection. The performance of the proposed control technique has been verified by simulation.

	Digital compensation of a high-frequency voltage-mode dc-dc converter By CHANG Wei-Hsu; HSIA Tsun-Hsiao; LIN Yu-Zheng; CHEN Dan; TSAI Hsien-Yi	[View] [Download]
Abstract: This paper explores the potential and the pitfall of digital compensation in a voltage-mode dc-dc converter. A FPGA-based synchronous DC-DC buck converter was used to implement the proposed two digital compensating schemes. One was to use a pair of complex compensating zeros and the other was to use a positive pole. Small-signal models of converters with digital control will be used to illustrate some basic concepts. Complex-zero compensation may improve the control loop gain characteristics but positive-pole compensation is infeasible

	Digital Control of a Three-Phase Four-Leg Inverter under Unbalanced Voltage Conditions By CUREA Octavian; VILLATE MARTINEZ Jose Luis; CAMBLONG Haritza; VECHIU Ionel; CEBALLOS Salva	[View] [Download]
Abstract: In this paper, the implementation of an innovative inverter control strategy based on the symmetrical components is presented. Symmetrical components of the inverter output voltage and current are decomposed into dq DC quantities to control a three-phase four-leg inverter. This kind of inverter can be a good choice for the applications with hybrid power system based on renewable energy used to supply unbalanced loads. The addition of a fourth leg provides an extra degree of freedom, making possible to handle the neutral current caused by the unbalanced load. Simulation results are compared with experimental results for a prototype inverter to verify the validity of the proposed control strategy.

	Dual-Inductive Snubber Circuit Design for Three-Level Inverter By ALNASSEIR Jamal; HEROLD Gerhard; WEINDL Christian	[View] [Download]
Abstract: A new circuit design for the protection of e.g. multi level converters will be presented in this paper. The so-called "dual-inductive snubber circuit design for three-level converter" will optimize the number of the total snubber circuit elements and the behavior RCD/ RLD snubber circuit especially in the direction of over-voltage and over-current, and will be suitable to be used in high power inverters as well as FACTS systems due to its features. The new design comprises most of the advantages of the common snubber circuit as a low number of components, improved efficiency and power semiconductor losses due to the low number of snubber elements, reduced over-voltage across the semiconductor devices and no balancing problems. The presented snubber circuit has been analyzed, compared, and confronted to the output of a standardized three level converter system to verify its advantages.

	FPGA based Sequential Switching control strategy for a Three Phase Inverter By JEZERNIK Karel; POLIC Ales	[View] [Download]
Abstract: This paper introduces a new sequential switching control strategy for a current control of a three phase inverter. The key idea, presented in this paper, is to integrate the benefits of the variable structure system control design and the event-driven sequential control structures to raise the system performance and to improve the control efficiency. Twofold design covers the switching conditions determination using the Lyapunov stability criteria and the event-driven sequential switching pattern design for the switching of inverter transistors. The proposed control design is applied for the control of three phase permanent magnet synchronous machine.

	FPGA-based Vector PI Regulator for Electrical Drives Control By MONMASSON Eric; ABDELLATIF Meriem; SLAMA-BELKHODJA Ilhem; NAOUAR Wissem	[View] [Download]
Abstract: This work presents the design of the hardware architecture of an optimized and reusable Vector PI (VPI) Regulator, which is implemented on a Field Programmable Gate Array (FPGA) target. It is especially dedicated for FPGA-based vector controls of AC drives, where two or more PI current regulators are required at the same time. So, using only one optimized VPI regulator instead of two optimized PI regulators is more advantageous, since it leads to a less consumption of the FPGA hardware resources. The developed VPI hardware architecture is tested through the FPGA implementation of a classical vector current controller, which is used for the current control of a three phase RL load. Experimental results carried on a prototyping platform are presented in order to illustrate the efficiency of the developed VPI hardware architecture.

	Output Voltage Distortion Compensation for Half-Bridge Inverters By CHEN Yaow-Ming	[View] [Download]
Abstract: This paper proposes a new control strategy for the half-bridge inverter with a compensation circuit to compensate the output voltage distortion caused by the voltage unbalance of the series connected input capacitors. It can extend the operation range of the half-bridge inverter without sacrificing the output power quality. The compensation circuit is activated only when the output voltage distortion occurs. The operation principle and control flowchart of the proposed compensation strategy are introduced. Hardware experimental results with different operation conditions are presented to verify the validity of the proposed compensation strategy.

	Predictive Direct Power Control of MV-Grid-connected Two-Level and Three-Level NPC Converters: Experimental Results By AURTENECHEA Sergio; RODRIGUEZ Miguel	[View] [Download]
Abstract: This paper deals with the Predictive Direct Power Control of MV-grid-connected two-level and three-level NPC converters. The well-known direct power control is combined with a predictive selection of a voltage-vectors sequence, obtaining both high transient dynamic and constant switching frequency on high-power converters. The initial Predictive Direct Power Control proposal explored only the basic formulation based on simple vector-sequences applied to two-level converters. Later on, the same approach was extended to the family of three-level NPC converters, including the predictive direct control of neural voltage. In the same way, an advanced hybrid Predictive Direct Power Control was presented, providing only simulated data. The work presented in this paper provides experimental results of the hybrid Predictive Direct Power Control applied to two-level and three-level NPC converters. These results show that the P-DPC approach is an attractive solution to MV grid-connected applications.

	PWM Rectifier with LCL-Filter using different Current Control Structures By DANNEHL Joerg; FUCHS Friedrich W.; HANSEN Steffan	[View] [Download]
Abstract: The control of a PWM rectifier with LCL-filter using a minimum number of sensors is analyzed. In addition to the DC-link voltage either the converter or line current is measured. Two different ways of current control are shown, analyzed and compared by simulations as well as experimental investigations. Main focus is spent on active damping of the LCL filter resonance and on robustness against line inductance variations.

	Three-Phase Inverter with Output LC Filter Using Predictive Control for UPS Applications By CORTES Patricio; RODRIGUEZ Jose	[View] [Download]
Abstract: The use of an inverter with an output LC filter allows for generation of sinusoidal voltages with low harmonic distortion. However, the controller design becomes more difficult. This paper presents a new and simple control scheme using predictive control. The controller uses a model of the system to predict, on each sampling interval, the behavior of the output voltage for each possible switching state, then a cost function is used as a criterion for selecting the switching state that will be applied during the next sampling interval.