EPE Association: EPE 2013 - DS1h: FACTS, D-FACTS, Active filtering and other advanced grid side converter control

EPE 2013 - DS1h: FACTS, D-FACTS, Active filtering and other advanced grid side converter control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 16: Power electronics in transmission and distribution > EPE 2013 - DS1h: FACTS, D-FACTS, Active filtering and other advanced grid side converter control

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   Active filtering for the neutral conductor current using several current harmonics to reducethe costs of operation
By Ismael SHAKRA [View]
[Download]

Abstract: The current harmonics can cause many problems for the electric power system, particularly the neutral conductor in the three-phase four-wire system. Active filter is known as the useful method for harmonic mitigation. Nevertheless, additional active filters increase system costs. In our work, the current harmonics will be only regulated to the specified values that should not be exceeded. We want to prove that the filter current with several current harmonics is less than the filter current with a current harmonic. So the proposed method in our work leads to a good technical solution. Moreover it can reduce the costs of operation and we need so small filter elements.

   An Application of Improved Synchronous Reference Frame-Based Voltage Sag Detection in Voltage Sag Compensation Systems
By Yuttana KUMSUWAN, Yutthachai SILLAPAWICHARN [View]
[Download]

Abstract: This paper proposes an application of improved synchronous reference frame (ISRF)-based voltage sag detection in voltage sag compensation system. The ISRF-based voltage sag detection presents the fast detection time that is suitable to use in voltage sag compensation system. The proposed voltage sag compensation system consists of 1) ISRF-based voltage sag detector, 2) static transfer switches (STSs), and 3) alternative voltage source using the inverter. In a normal incident, the load fed the power from main voltage source via the main STS. When the voltage sag occurs and it is detected by the voltage sag detector, the alternative STS connects the load to an alternative voltage source instead of the main STS. The computer software simulation and the experiment were made to investigate and verify the operation of proposed voltage sag compensation system. It can be seen from the results that a short voltage sag detection time is obtained and voltage sag can be compensated with the proposed system.

   Central Difference Model Predictive Current Control of Single-Phase H-bridge inverter with LCL Filter
By Jakub TALLA, Zdenek PEROUTKA, Vojtech BLAHNIK [View]
[Download]

Abstract: This paper describes a central difference based model predictive control of a Single-Phase H-bridge inverter with a LCL output passive filter. The central difference model predictive control (CDMPC) is a novel approach for linear system control based on a central difference theorem. The single-phase H-bridge is driven by the pulsewidth-modulation-based (PWM) method with signal A/D sampling controlled by the PWM periphery and it has one step time delay in the actuation. This delay is compensated by the Smith predictor. The theoretical conclusions are verified by simulations.

   Double Frame Control and Power Compensation for Power Converters Connected to Weak Grids
By Daniel SIEMASZKO [View]
[Download]

Abstract: CERN is studying the implementation of high power active front ends, implying the operation of a voltage source inverters connected to a grid that can be considered as weak when compared to the converter nominal power. Proper synchronisation is a key point for current control stability. The handling of networks with asymmetric disturbances implies the accurate handling of the second harmonic component appearing under unbalanced networks by the proper decoupling of the positive and negative sequence of the network voltages and currents. The use of a double frame controller allow the full control of phase current symmetry or the compensation instantaneous active power oscillation.

   EXPERIMENTAL VALIDATION OF NEW DIRECT POWER CONTROL SWITCHING TABLE FOR SHUNT ACTIVE POWER FILTER
By Abdelmadjid CHAOUI, Jean-Paul GAUBERT, Abdelouahab BOUAFIA [View]
[Download]

Abstract: This paper deals with a new concept and analysis of direct power control (DPC) switching table for a three phase shunt active power filter (SAPF) to improve power quality. The active power reference is obtained from the VSI dc-bus voltage controlled at the required level using an integrator proportional corrector. Compared to their references, active and reactive powers are directly controlled by selecting the optimal vector using a new switching table. From the SAPF’s equivalent scheme analysis the instantaneous active and reactive powers (IARP) variations are obtained. The new predefined switching table is designed based on comparative study and voltage source inverter (VSI) switching vectors effect on the total IARP variations. The main advantages of this control technique are that it provides a sinusoidal source current and unity power factor with no need of linear current controllers and coordinates transformations or modulators. Extensive simulation and experimental results, obtained from steady and transient states, prove the excellent performance and verify the validity and effectiveness of the proposed power control for improving the power quality.

   Experimental Verification of Single-phase Inverter with Power Decoupling Function using Boost-up Chopper
By Jun-ichi ITOH, Hiroki WATANABE, Kazuhiro KOIWA, Yoshiya OHNUMA [View]
[Download]

Abstract: This paper discusses a circuit configuration for a single-phase voltage source inverter that features power decoupling function. Generally, the converter that is connected to a single-phase power grid is required to decouple the power ripple with a twice frequency of the power grid. The proposed circuit compensates the single-phase power ripple by using an active buffer with small capacitors 50µF at 200 W. In this paper, the fundamental operations of the proposed converter are confirmed by experimental results. Then, the proposed converter is evaluated with the maximum power point tracking (MPPT) under a simulated photovoltaic (PV) conditions. From the experimental results, the output current Total Harmonic Distortion (THD) is 3.51\% and the output power factor is over 99\%. In addition, the input current ripple is reduced 12.3\%. Moreover, from the loss analysis, the maximum efficiency of the inverter including the active buffer circuit is 95.5\%.

   High Performance Controller with Effective Voltage Balance Regulation for a Cascade STATCOM with Star Configuration Under Unbalanced Conditions
By Longcheng TAN, Song WANG, Ping WANG, Yaohua LI, Qiongxuan GE, Hongtao REN, Pengxian SONG [View]
[Download]

Abstract: A high performance controller with effective voltage balance regulation is proposed for a cascade STATtic synchronous COMpensator(STATCOM) with star configuration. Zero-sequence voltages are injected to the output voltages of STATCOM in order to compensate the unblanced load currents, which can also decouple the star-connected three-phase STATCOM system into three single-phase systems. Additionally, an effective voltage balance control method and a robust current tracking technique are proposed to guarantee all capacitor voltages balanced and to ensure good current tracking ability. Moreover, a quick and accurate current extraction method is proposed to obtain the negative and reactive currents of unblanced loads to improve the system’s dynamic response. The proposed control method is validated on a 10kV/±1Mvar cascade star-connected STATCOM industrial prototype. All the experimental results verify that with the proposed control methods the STATCOM can compensate unblanced load currents with quick dynamic response while keeping all capacitor voltages balanced.

   IMPACT OF DIFFERENT STATIC LOAD CHARACTERISTICS ON POWER OSCILLATION DAMPING BY SHUNT CONNECTED FACTS DEVICES
By Mebtu BEZA, Massimo BONGIORNO [View]
[Download]

Abstract: Loads constitute a major part of the power system and their characteristics greatly influence the stable operation of the system. One of the problems that are encountered in the power system is low-frequency electromechanical oscillations following disturbances. This paper deals with analysis of the impact of different static load characteristics on the performance of Power Oscillation Damping (POD) controllers by shunt-connected FACTS devices. From the results of the analysis, a modification to the POD controller will be proposed to deal with the impact of the load characteristics and its performance will be validated through small signal analysis and time domain simulation.

   Lifting Wavelet Transform and Energy Operator Synchronization for a Flying Capacitor Multi-Level Based Active Power Filter
By Chigozie NWOBU, Li ZHANG [View]
[Download]

Abstract: An online harmonic estimation technique is proposed based on lifting wavelet transforms. The effectiveness of this technique is successfully verified in the paper through analyzing the current samples supplied to a practical building network which are unbalanced and corrupted with noise. Combining with a novel synchronization technique based on the energy operator principle, this scheme is applied to control a flying capacitor multilevel inverter based active power filter shunt connected to a power network. Simulation study has shown that the performance of this filtering technique is superior than the conventional synchronous reference frame based harmonic elimination method.

   Single phase to balanced three phase load converter control
By Adria JUNYENT-FERRE, Marc CHEAH-MANE, Eduardo PRIETO-ARAUJO, Oriol GOMIS-BELLMUNT [View]
[Download]

Abstract: This paper presents a discussion and an analysis of a static synchronous compensator (STATCOM) device meant for compensating the unbalance produced by a single phase load connected between one phase and the neutral and the design of its closed-loop control. The concept is tested experimentally using a small scale test platform.

   VSC Topology Comparison For STATCOM Application Under Unbalanced Conditions
By Aitor LAKA, Jon Andoni BARRENA, Javier CHIVITE-ZABALZA, Miguel Angel RODRIGUEZ, Andrew CROSS [View]
[Download]

Abstract: This paper compares the performance of four different power electronic converter topologies, which have been proposed for STATCOM applications. Two of the topologies are Modular Multilevel Cascaded Converters (MMCC), whilst the remaining circuits utilize magnetic elements and an open-winding transformer configuration to combine individual power modules. It is assumed that the STATCOM has to work under unbalanced conditions, so that it delivers both positive and negative sequence currents. Simulation studies for the four topologies have been carried out using the simulation tool Saber.

EPE 2013 - DS1h: FACTS, D-FACTS, Active filtering and other advanced grid side converter control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 16: Power electronics in transmission and distribution > EPE 2013 - DS1h: FACTS, D-FACTS, Active filtering and other advanced grid side converter control
	[return to parent folder]

	Active filtering for the neutral conductor current using several current harmonics to reducethe costs of operation By Ismael SHAKRA	[View] [Download]
Abstract: The current harmonics can cause many problems for the electric power system, particularly the neutral conductor in the three-phase four-wire system. Active filter is known as the useful method for harmonic mitigation. Nevertheless, additional active filters increase system costs. In our work, the current harmonics will be only regulated to the specified values that should not be exceeded. We want to prove that the filter current with several current harmonics is less than the filter current with a current harmonic. So the proposed method in our work leads to a good technical solution. Moreover it can reduce the costs of operation and we need so small filter elements.

	An Application of Improved Synchronous Reference Frame-Based Voltage Sag Detection in Voltage Sag Compensation Systems By Yuttana KUMSUWAN, Yutthachai SILLAPAWICHARN	[View] [Download]
Abstract: This paper proposes an application of improved synchronous reference frame (ISRF)-based voltage sag detection in voltage sag compensation system. The ISRF-based voltage sag detection presents the fast detection time that is suitable to use in voltage sag compensation system. The proposed voltage sag compensation system consists of 1) ISRF-based voltage sag detector, 2) static transfer switches (STSs), and 3) alternative voltage source using the inverter. In a normal incident, the load fed the power from main voltage source via the main STS. When the voltage sag occurs and it is detected by the voltage sag detector, the alternative STS connects the load to an alternative voltage source instead of the main STS. The computer software simulation and the experiment were made to investigate and verify the operation of proposed voltage sag compensation system. It can be seen from the results that a short voltage sag detection time is obtained and voltage sag can be compensated with the proposed system.

	Central Difference Model Predictive Current Control of Single-Phase H-bridge inverter with LCL Filter By Jakub TALLA, Zdenek PEROUTKA, Vojtech BLAHNIK	[View] [Download]
Abstract: This paper describes a central difference based model predictive control of a Single-Phase H-bridge inverter with a LCL output passive filter. The central difference model predictive control (CDMPC) is a novel approach for linear system control based on a central difference theorem. The single-phase H-bridge is driven by the pulsewidth-modulation-based (PWM) method with signal A/D sampling controlled by the PWM periphery and it has one step time delay in the actuation. This delay is compensated by the Smith predictor. The theoretical conclusions are verified by simulations.

	Double Frame Control and Power Compensation for Power Converters Connected to Weak Grids By Daniel SIEMASZKO	[View] [Download]
Abstract: CERN is studying the implementation of high power active front ends, implying the operation of a voltage source inverters connected to a grid that can be considered as weak when compared to the converter nominal power. Proper synchronisation is a key point for current control stability. The handling of networks with asymmetric disturbances implies the accurate handling of the second harmonic component appearing under unbalanced networks by the proper decoupling of the positive and negative sequence of the network voltages and currents. The use of a double frame controller allow the full control of phase current symmetry or the compensation instantaneous active power oscillation.

	EXPERIMENTAL VALIDATION OF NEW DIRECT POWER CONTROL SWITCHING TABLE FOR SHUNT ACTIVE POWER FILTER By Abdelmadjid CHAOUI, Jean-Paul GAUBERT, Abdelouahab BOUAFIA	[View] [Download]
Abstract: This paper deals with a new concept and analysis of direct power control (DPC) switching table for a three phase shunt active power filter (SAPF) to improve power quality. The active power reference is obtained from the VSI dc-bus voltage controlled at the required level using an integrator proportional corrector. Compared to their references, active and reactive powers are directly controlled by selecting the optimal vector using a new switching table. From the SAPF’s equivalent scheme analysis the instantaneous active and reactive powers (IARP) variations are obtained. The new predefined switching table is designed based on comparative study and voltage source inverter (VSI) switching vectors effect on the total IARP variations. The main advantages of this control technique are that it provides a sinusoidal source current and unity power factor with no need of linear current controllers and coordinates transformations or modulators. Extensive simulation and experimental results, obtained from steady and transient states, prove the excellent performance and verify the validity and effectiveness of the proposed power control for improving the power quality.

	Experimental Verification of Single-phase Inverter with Power Decoupling Function using Boost-up Chopper By Jun-ichi ITOH, Hiroki WATANABE, Kazuhiro KOIWA, Yoshiya OHNUMA	[View] [Download]
Abstract: This paper discusses a circuit configuration for a single-phase voltage source inverter that features power decoupling function. Generally, the converter that is connected to a single-phase power grid is required to decouple the power ripple with a twice frequency of the power grid. The proposed circuit compensates the single-phase power ripple by using an active buffer with small capacitors 50µF at 200 W. In this paper, the fundamental operations of the proposed converter are confirmed by experimental results. Then, the proposed converter is evaluated with the maximum power point tracking (MPPT) under a simulated photovoltaic (PV) conditions. From the experimental results, the output current Total Harmonic Distortion (THD) is 3.51\% and the output power factor is over 99\%. In addition, the input current ripple is reduced 12.3\%. Moreover, from the loss analysis, the maximum efficiency of the inverter including the active buffer circuit is 95.5\%.

	High Performance Controller with Effective Voltage Balance Regulation for a Cascade STATCOM with Star Configuration Under Unbalanced Conditions By Longcheng TAN, Song WANG, Ping WANG, Yaohua LI, Qiongxuan GE, Hongtao REN, Pengxian SONG	[View] [Download]
Abstract: A high performance controller with effective voltage balance regulation is proposed for a cascade STATtic synchronous COMpensator(STATCOM) with star configuration. Zero-sequence voltages are injected to the output voltages of STATCOM in order to compensate the unblanced load currents, which can also decouple the star-connected three-phase STATCOM system into three single-phase systems. Additionally, an effective voltage balance control method and a robust current tracking technique are proposed to guarantee all capacitor voltages balanced and to ensure good current tracking ability. Moreover, a quick and accurate current extraction method is proposed to obtain the negative and reactive currents of unblanced loads to improve the system’s dynamic response. The proposed control method is validated on a 10kV/±1Mvar cascade star-connected STATCOM industrial prototype. All the experimental results verify that with the proposed control methods the STATCOM can compensate unblanced load currents with quick dynamic response while keeping all capacitor voltages balanced.

	IMPACT OF DIFFERENT STATIC LOAD CHARACTERISTICS ON POWER OSCILLATION DAMPING BY SHUNT CONNECTED FACTS DEVICES By Mebtu BEZA, Massimo BONGIORNO	[View] [Download]
Abstract: Loads constitute a major part of the power system and their characteristics greatly influence the stable operation of the system. One of the problems that are encountered in the power system is low-frequency electromechanical oscillations following disturbances. This paper deals with analysis of the impact of different static load characteristics on the performance of Power Oscillation Damping (POD) controllers by shunt-connected FACTS devices. From the results of the analysis, a modification to the POD controller will be proposed to deal with the impact of the load characteristics and its performance will be validated through small signal analysis and time domain simulation.

	Lifting Wavelet Transform and Energy Operator Synchronization for a Flying Capacitor Multi-Level Based Active Power Filter By Chigozie NWOBU, Li ZHANG	[View] [Download]
Abstract: An online harmonic estimation technique is proposed based on lifting wavelet transforms. The effectiveness of this technique is successfully verified in the paper through analyzing the current samples supplied to a practical building network which are unbalanced and corrupted with noise. Combining with a novel synchronization technique based on the energy operator principle, this scheme is applied to control a flying capacitor multilevel inverter based active power filter shunt connected to a power network. Simulation study has shown that the performance of this filtering technique is superior than the conventional synchronous reference frame based harmonic elimination method.

	Single phase to balanced three phase load converter control By Adria JUNYENT-FERRE, Marc CHEAH-MANE, Eduardo PRIETO-ARAUJO, Oriol GOMIS-BELLMUNT	[View] [Download]
Abstract: This paper presents a discussion and an analysis of a static synchronous compensator (STATCOM) device meant for compensating the unbalance produced by a single phase load connected between one phase and the neutral and the design of its closed-loop control. The concept is tested experimentally using a small scale test platform.

	VSC Topology Comparison For STATCOM Application Under Unbalanced Conditions By Aitor LAKA, Jon Andoni BARRENA, Javier CHIVITE-ZABALZA, Miguel Angel RODRIGUEZ, Andrew CROSS	[View] [Download]
Abstract: This paper compares the performance of four different power electronic converter topologies, which have been proposed for STATCOM applications. Two of the topologies are Modular Multilevel Cascaded Converters (MMCC), whilst the remaining circuits utilize magnetic elements and an open-winding transformer configuration to combine individual power modules. It is assumed that the STATCOM has to work under unbalanced conditions, so that it delivers both positive and negative sequence currents. Simulation studies for the four topologies have been carried out using the simulation tool Saber.