EPE Association: EPE 2003 - Topic 04b: Converter Control, Current / Voltage Control

EPE 2003 - Topic 04b: Converter Control, Current / Voltage Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2003 - Conference > EPE 2003 - Topic 04: MODULATION STRATEGIES AND SPECIFIC CONTROL METHODS FOR STATIC CONVERTER > EPE 2003 - Topic 04b: Converter Control, Current / Voltage Control

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   Non-equilibrium state capacitor voltage stabilization in a hybrid asymmetric nine-level inverter: Non-linear model-predictive control
By M. Veenstra; A. Rufer [View]
[Download]

Abstract: Hybrid asymmetric multi-level inverters promise significant improvements for medium-voltage industrial drives. Floating sub inverters without feeding allow increased eciency, but can only supply reactive power. An on-line non-linear model-predictive controller stabilizes their intermediate-circuit capacitor voltages in steady-state and during transients, as demonstrated by simulations and measurements.

   Converter flux linkage oriented current vector control using synchronous co-ordinate vector modulation
By A. Tarkiainen; R. Pöllänen; M. Niemelä; J. Pyrhönen [View]
[Download]

Abstract: Article presents an application of DTC-type synchronous co-ordinate vector modulation method to the converter flux linkage oriented current vector control. Two control structures are implemented: one which uses a voltage vector controlled modulation and the other that uses a direct synchronous frame current hysteresis control to fulfill the current references. The article shows that the DTC-type optimum switching table based hysteresis control may be used in controlling the converter voltage vector or the current vector in the synchronous frame. Practical measurements with industrial line converter show the high dynamical performance of the proposed control structures.

   A complete methodology for the design of a digital control law for PWM inverters
By E. Godoy - E. Ostertag [View]
[Download]

Abstract: To assume the digital regulation of the output voltage of a PWM inverter, the authors present a complete methodology for the design of a control law allowing to take into account the current limitation and perturbations such as the dead time of commutation of the IGBT. In this paper the control law proposed is organized around two feedback control loops: a primary loop dealing with the output voltage and a secondary loop controlling the output inductance current. The controller coefficients are easily obtained by a simple matrix inversion, thus enabling a relatively easy implementation of the automatic regulator parameter computation.

   A new strategy based on peak current control and fixed switching frequency for a multilevel voltage source converter
By M. Aimé; G. Gateau; T.A. Meynard [View]
[Download]

Abstract: The Peak Current Control is a strategy widely used to control devices such as forward converters or two-level choppers. The main advantages of this strategy are the fixed switching frequency of the output voltage and the fast dynamic response of the current loop. This strategy was originally designed only for two-level dc-to-dc converters. This paper presents a strategy inspired by the Peak Current Control and intended to control multilevel converters (inverters or choppers). This multilevel control strategy preserves the same qualities as the Peak Current Control and also introduces a static error. The principle of this strategy is explained, and the results obtained by digital simulations are presented and discussed.

   Digital current control of utility-connected three-phase PWM voltage source inverters
By S. M Abu-Sharkh; M. A Abu-Sara [View]
[Download]

Abstract: This paper discusses the design of a digital current controller for three-phase utility-connected 2-level and 3-level PWM inverters with output LCL filters in which the filter capacitors are connected to the dc link rails. The controller has a two-loop feedback structure, with an additional feedforward loop to compensate for utility voltage harmonic disturbance. A detailed analysis of the effect of the controller microprocessor time delay on the stability and transient response of the controller is presented. Analytical and simulation results are presented for both the 2-level and the 3-level inverter systems, demonstrating the effectiveness of the proposed controller in producing good quality current with low THD. The results confirm that using a 3-level inverter has the advantage of halving the current ripple in the filter’s main inductors, at the expense of extra inverter power devices and electronic hardware and software complexity. Experimental results for a 2-level inverter system are also presented.

   Robust average current-mode control of boost DC-DC converter
By E. Figueres; J. M. Benavent; G. Garcerá; J. Sandía [View]
[Download]

Abstract: The control of boost dc-dc converters by means of a new Average Current-mode Control (ACC) scheme with robust performance and improved dynamic response is proposed in this paper. The new Reference Model Control-ACC (MR-ACC) significantly improves the converter disturbance rejection properties, maintaining proper stability in a wide range of operation points.

   Predictive relay space vector control of the AC electric drives
By R.T. Shreiner; A.A. Efimov; G.S. Zinovyev; K.N. Korukov; I.A. Mukhamatshin; A.I. Kalygin [View]
[Download]

Abstract: The paper presents a design conception of the automatic control system (ACS) based on the predictive relay space vector algorithm and applicable to the ac electrical drives with different types of semiconductor frequency converters. As an example, the ACS of the active voltage and active current rectifier, direct frequency converter and induction drive with the voltage source inverter are considered. The simulation and experimental results are presented.

   Improved voltage compensator for digitally controlled boost PFC converters
By F. M.L.L. De Belie; D. M. Van de Sype; K. De Gussemé; J. A. A. Melkebeek [View]
[Download]

Abstract: A novel digital voltage controller for boost PFC converters is presented in this paper. Some controlled boost PFC converters emulate a resistive input impedance to the mains by forcing the line current to track the wave shape of the mains voltage. In that way these converters exhibit a low THD of the AC input current and maintain a high power factor. However, as an analogue voltage controller is applied to maintain a constant DC output voltage, the DC-bus voltage ripple, pulsating at twice the grid frequency, injects a third harmonic of considerable magnitude in the AC input current. Over the last decade, several voltage control strategies for lowering third harmonic distortion in the line current, have been reported in the literature. One of the output voltage control algorithms that catches the eye due to its straightforwardness and to its intrinsic discrete-time approach, is the sample-and-hold method. The proposed digital voltage compensator is an improvement of this method. By sampling the DC-bus voltage at all zeroes of its ripple, the new strategy results in a fast voltage control algorithm that guarantees low total harmonic distortion in the AC input current. The timing of the zeroes in the ripple of the DC-bus voltage for a rated load as well as for a light load and the reduction of the ripple in the sampled DC-bus voltage are described. The good results of a voltage compensator based on the proposed sample-and-hold method and the improvements of such a compensator against commonly employed voltage controllers are verified experimentally using a digitally controlled boost PFC converter.

   On-line capacitance estimation of DC-link capacitor by input current injection for PWM conveters
By D.-C. Lee; K.-J. Lee; J.-K. Seok; J.-W. Choi [View]
[Download]

Abstract: In this paper, a novel on-line capacitance estimation of dc link capacitor using input current injection is proposed for the ac/dc PWM converters. At no load, a controlled input current at a lower frequency than the line frequency is injected into the input side, which causes the dc voltage ripples at the output side. With the ac voltage and current ripple components on the dc side extracted by the digital filters, the capacitance can be calculated simply through a voltage-current relationship. This method can be implemented only by software without any additional hardware. It is shown that the estimation error is less than 1.5% from the experimental result.

   Supply voltage sensorless reactive power control of DTC modulation based line converter with L- and LCL-filters
By R. Pöllänen; A. Tarkiainen; M. Niemelä; J. Pyrhönen [View]
[Download]

Abstract: The reactive power control of a modern current controlled line converter without source voltage sensors is described. Current vector control is implemented using synchronous coordinates PI controllers and a high performance direct torque control (DTC) based modulation technique. Both Land LCL-type line filters are considered. With L-filter two strategies for reactive power control are proposed: firstly, an open loop control and, secondly, a feedback control based on estimated reactive power. In the case of an LCL-filter, a combined open loop and feedback control is introduced. The influence of the line filter parameter mismatch on the performance of the estimation based control schemes is investigated. Experimental results are presented to proof the competent performance of the proposed reactive power control methods.

   Passivity-based control of the shunt active power filters
By Q. Zhong; K.W. E. Cheng; N. C. Cheung; J. Pan; J. Wu [View]
[Download]

Abstract: This paper applies the passivity-based control into the active power filters. After simplifying the circuit of the APF, we build the model of it. The voltage of load and the current of supply are considered as the state variables of the system. We take the compensating current as the control variable. Then the control law is performed by passivity theory. Though the theory is complex, the application of the control law obtained by the passivity is very simple. We do simulation with the capacitive load, inductive load and various loads, and the results indicate the very good stability and robustness of the PBC.

   A novel inrush current limiting technique for low voltage synchronous DC-DC converters
By M. Manolarou; G. Kostakis; S.N. Manias [View]
[Download]

Abstract: In this paper a novel inrush current limiting technique for low voltage dc/dc converters is presented and analyzed. The proposed circuit overcomes the drawbacks of the already existing techniques, where power semiconductor devices are used in series with the common ground wire. The proposed circuit utilizes N Power MOSFET at the positive line (uninterrupted ground) and the magnitude of the inrush current is precisely controlled. On the other hand, the need of crow bar circuit for input isolation is eliminated. The experimental results were in close agreement with the theoretical and simulated ones.

   FPGA-based current control of PWM voltage-source inverters
By K. De Brabandere; J. Van den Keybus; B. Bolsens; J. Driesen; R. Belmans [View]
[Download]

Abstract: In this paper, a single-phase deadbeat digital current control algorithm using voltage source inverters for grid-connected applications is presented. The controller is designed directly in the digital domain using the method of Ragazzini. The line voltage is estimated by bandpass filtering the current error. The development of a robust fast prototyping platform, consisting of a Field Programmable Gate Array (FPGA) and a Digital Signal Processor (DSP), is discussed. The current control algorithm is implemented on a Digital Signal Processer, while the Pulse Width Modulation (PWM) algorithm and additional protection blocks are implemented in the FPGA. Both the simulations and the experimental results validate the results of the theoretical analysis. Specific advantages of the proposed current control algorithm include the fast and accurate deadbeat response, the robust operation and the avoidance of the use of a line voltage sensor.

   Voltage regulation system design for the four-leg converter
By V. Soares; P. Verdelho [View]
[Download]

Abstract: This paper presents the voltage regulation system design for a three-phase four-wire voltage converter. The regulation system is applied to a four-leg voltage source converter connected to the ac mains. Dc voltage regulation system is analysed and the controller synthesis is realized. Simulation and experimental results highlight the voltage regulation characteristics in terms of dynamic and steady-state behaviour and also for robustness to disturbances influence.

   Discrete-event converter control
By J. Böcker [View]
[Download]

Abstract: Hysteresis control is a fast and robust control approach but it is mostly applied only to simple converter systems. Considering such controllers as discrete-event systems opens a more systematic view and enables the controller design even for complex converter systems like a multi-system auxiliary converter as presented here. The controller is realized without any processor only on a FPGA device.

   Self oscillating current controllers: principles and applications
By J. Pierquin; B. Robyns; J.-P. Hautier [View]
[Download]

Abstract: This paper deals with a non-linear current control technique. This control is based on the self-oscillation phenomenon induced by the non-linearity of the power converter and an added element in the control loop. Its principle is analysed by the harmonic balance method. Two control schemes are proposed: a classic structure based on a low pass nature filter and an original digital structure based on a sample-andhold circuit. Experimental results point out the efficiency of both control strategies.

EPE 2003 - Topic 04b: Converter Control, Current / Voltage Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2003 - Conference > EPE 2003 - Topic 04: MODULATION STRATEGIES AND SPECIFIC CONTROL METHODS FOR STATIC CONVERTER > EPE 2003 - Topic 04b: Converter Control, Current / Voltage Control
	[return to parent folder]

	Non-equilibrium state capacitor voltage stabilization in a hybrid asymmetric nine-level inverter: Non-linear model-predictive control By M. Veenstra; A. Rufer	[View] [Download]
Abstract: Hybrid asymmetric multi-level inverters promise significant improvements for medium-voltage industrial drives. Floating sub inverters without feeding allow increased eciency, but can only supply reactive power. An on-line non-linear model-predictive controller stabilizes their intermediate-circuit capacitor voltages in steady-state and during transients, as demonstrated by simulations and measurements.

	Converter flux linkage oriented current vector control using synchronous co-ordinate vector modulation By A. Tarkiainen; R. Pöllänen; M. Niemelä; J. Pyrhönen	[View] [Download]
Abstract: Article presents an application of DTC-type synchronous co-ordinate vector modulation method to the converter flux linkage oriented current vector control. Two control structures are implemented: one which uses a voltage vector controlled modulation and the other that uses a direct synchronous frame current hysteresis control to fulfill the current references. The article shows that the DTC-type optimum switching table based hysteresis control may be used in controlling the converter voltage vector or the current vector in the synchronous frame. Practical measurements with industrial line converter show the high dynamical performance of the proposed control structures.

	A complete methodology for the design of a digital control law for PWM inverters By E. Godoy - E. Ostertag	[View] [Download]
Abstract: To assume the digital regulation of the output voltage of a PWM inverter, the authors present a complete methodology for the design of a control law allowing to take into account the current limitation and perturbations such as the dead time of commutation of the IGBT. In this paper the control law proposed is organized around two feedback control loops: a primary loop dealing with the output voltage and a secondary loop controlling the output inductance current. The controller coefficients are easily obtained by a simple matrix inversion, thus enabling a relatively easy implementation of the automatic regulator parameter computation.

	A new strategy based on peak current control and fixed switching frequency for a multilevel voltage source converter By M. Aimé; G. Gateau; T.A. Meynard	[View] [Download]
Abstract: The Peak Current Control is a strategy widely used to control devices such as forward converters or two-level choppers. The main advantages of this strategy are the fixed switching frequency of the output voltage and the fast dynamic response of the current loop. This strategy was originally designed only for two-level dc-to-dc converters. This paper presents a strategy inspired by the Peak Current Control and intended to control multilevel converters (inverters or choppers). This multilevel control strategy preserves the same qualities as the Peak Current Control and also introduces a static error. The principle of this strategy is explained, and the results obtained by digital simulations are presented and discussed.

	Digital current control of utility-connected three-phase PWM voltage source inverters By S. M Abu-Sharkh; M. A Abu-Sara	[View] [Download]
Abstract: This paper discusses the design of a digital current controller for three-phase utility-connected 2-level and 3-level PWM inverters with output LCL filters in which the filter capacitors are connected to the dc link rails. The controller has a two-loop feedback structure, with an additional feedforward loop to compensate for utility voltage harmonic disturbance. A detailed analysis of the effect of the controller microprocessor time delay on the stability and transient response of the controller is presented. Analytical and simulation results are presented for both the 2-level and the 3-level inverter systems, demonstrating the effectiveness of the proposed controller in producing good quality current with low THD. The results confirm that using a 3-level inverter has the advantage of halving the current ripple in the filter’s main inductors, at the expense of extra inverter power devices and electronic hardware and software complexity. Experimental results for a 2-level inverter system are also presented.

	Robust average current-mode control of boost DC-DC converter By E. Figueres; J. M. Benavent; G. Garcerá; J. Sandía	[View] [Download]
Abstract: The control of boost dc-dc converters by means of a new Average Current-mode Control (ACC) scheme with robust performance and improved dynamic response is proposed in this paper. The new Reference Model Control-ACC (MR-ACC) significantly improves the converter disturbance rejection properties, maintaining proper stability in a wide range of operation points.

	Predictive relay space vector control of the AC electric drives By R.T. Shreiner; A.A. Efimov; G.S. Zinovyev; K.N. Korukov; I.A. Mukhamatshin; A.I. Kalygin	[View] [Download]
Abstract: The paper presents a design conception of the automatic control system (ACS) based on the predictive relay space vector algorithm and applicable to the ac electrical drives with different types of semiconductor frequency converters. As an example, the ACS of the active voltage and active current rectifier, direct frequency converter and induction drive with the voltage source inverter are considered. The simulation and experimental results are presented.

	Improved voltage compensator for digitally controlled boost PFC converters By F. M.L.L. De Belie; D. M. Van de Sype; K. De Gussemé; J. A. A. Melkebeek	[View] [Download]
Abstract: A novel digital voltage controller for boost PFC converters is presented in this paper. Some controlled boost PFC converters emulate a resistive input impedance to the mains by forcing the line current to track the wave shape of the mains voltage. In that way these converters exhibit a low THD of the AC input current and maintain a high power factor. However, as an analogue voltage controller is applied to maintain a constant DC output voltage, the DC-bus voltage ripple, pulsating at twice the grid frequency, injects a third harmonic of considerable magnitude in the AC input current. Over the last decade, several voltage control strategies for lowering third harmonic distortion in the line current, have been reported in the literature. One of the output voltage control algorithms that catches the eye due to its straightforwardness and to its intrinsic discrete-time approach, is the sample-and-hold method. The proposed digital voltage compensator is an improvement of this method. By sampling the DC-bus voltage at all zeroes of its ripple, the new strategy results in a fast voltage control algorithm that guarantees low total harmonic distortion in the AC input current. The timing of the zeroes in the ripple of the DC-bus voltage for a rated load as well as for a light load and the reduction of the ripple in the sampled DC-bus voltage are described. The good results of a voltage compensator based on the proposed sample-and-hold method and the improvements of such a compensator against commonly employed voltage controllers are verified experimentally using a digitally controlled boost PFC converter.

	On-line capacitance estimation of DC-link capacitor by input current injection for PWM conveters By D.-C. Lee; K.-J. Lee; J.-K. Seok; J.-W. Choi	[View] [Download]
Abstract: In this paper, a novel on-line capacitance estimation of dc link capacitor using input current injection is proposed for the ac/dc PWM converters. At no load, a controlled input current at a lower frequency than the line frequency is injected into the input side, which causes the dc voltage ripples at the output side. With the ac voltage and current ripple components on the dc side extracted by the digital filters, the capacitance can be calculated simply through a voltage-current relationship. This method can be implemented only by software without any additional hardware. It is shown that the estimation error is less than 1.5% from the experimental result.

	Supply voltage sensorless reactive power control of DTC modulation based line converter with L- and LCL-filters By R. Pöllänen; A. Tarkiainen; M. Niemelä; J. Pyrhönen	[View] [Download]
Abstract: The reactive power control of a modern current controlled line converter without source voltage sensors is described. Current vector control is implemented using synchronous coordinates PI controllers and a high performance direct torque control (DTC) based modulation technique. Both Land LCL-type line filters are considered. With L-filter two strategies for reactive power control are proposed: firstly, an open loop control and, secondly, a feedback control based on estimated reactive power. In the case of an LCL-filter, a combined open loop and feedback control is introduced. The influence of the line filter parameter mismatch on the performance of the estimation based control schemes is investigated. Experimental results are presented to proof the competent performance of the proposed reactive power control methods.

	Passivity-based control of the shunt active power filters By Q. Zhong; K.W. E. Cheng; N. C. Cheung; J. Pan; J. Wu	[View] [Download]
Abstract: This paper applies the passivity-based control into the active power filters. After simplifying the circuit of the APF, we build the model of it. The voltage of load and the current of supply are considered as the state variables of the system. We take the compensating current as the control variable. Then the control law is performed by passivity theory. Though the theory is complex, the application of the control law obtained by the passivity is very simple. We do simulation with the capacitive load, inductive load and various loads, and the results indicate the very good stability and robustness of the PBC.

	A novel inrush current limiting technique for low voltage synchronous DC-DC converters By M. Manolarou; G. Kostakis; S.N. Manias	[View] [Download]
Abstract: In this paper a novel inrush current limiting technique for low voltage dc/dc converters is presented and analyzed. The proposed circuit overcomes the drawbacks of the already existing techniques, where power semiconductor devices are used in series with the common ground wire. The proposed circuit utilizes N Power MOSFET at the positive line (uninterrupted ground) and the magnitude of the inrush current is precisely controlled. On the other hand, the need of crow bar circuit for input isolation is eliminated. The experimental results were in close agreement with the theoretical and simulated ones.

	FPGA-based current control of PWM voltage-source inverters By K. De Brabandere; J. Van den Keybus; B. Bolsens; J. Driesen; R. Belmans	[View] [Download]
Abstract: In this paper, a single-phase deadbeat digital current control algorithm using voltage source inverters for grid-connected applications is presented. The controller is designed directly in the digital domain using the method of Ragazzini. The line voltage is estimated by bandpass filtering the current error. The development of a robust fast prototyping platform, consisting of a Field Programmable Gate Array (FPGA) and a Digital Signal Processor (DSP), is discussed. The current control algorithm is implemented on a Digital Signal Processer, while the Pulse Width Modulation (PWM) algorithm and additional protection blocks are implemented in the FPGA. Both the simulations and the experimental results validate the results of the theoretical analysis. Specific advantages of the proposed current control algorithm include the fast and accurate deadbeat response, the robust operation and the avoidance of the use of a line voltage sensor.

	Voltage regulation system design for the four-leg converter By V. Soares; P. Verdelho	[View] [Download]
Abstract: This paper presents the voltage regulation system design for a three-phase four-wire voltage converter. The regulation system is applied to a four-leg voltage source converter connected to the ac mains. Dc voltage regulation system is analysed and the controller synthesis is realized. Simulation and experimental results highlight the voltage regulation characteristics in terms of dynamic and steady-state behaviour and also for robustness to disturbances influence.

	Discrete-event converter control By J. Böcker	[View] [Download]
Abstract: Hysteresis control is a fast and robust control approach but it is mostly applied only to simple converter systems. Considering such controllers as discrete-event systems opens a more systematic view and enables the controller design even for complex converter systems like a multi-system auxiliary converter as presented here. The controller is realized without any processor only on a FPGA device.

	Self oscillating current controllers: principles and applications By J. Pierquin; B. Robyns; J.-P. Hautier	[View] [Download]
Abstract: This paper deals with a non-linear current control technique. This control is based on the self-oscillation phenomenon induced by the non-linearity of the power converter and an added element in the control loop. Its principle is analysed by the harmonic balance method. Two control schemes are proposed: a classic structure based on a low pass nature filter and an original digital structure based on a sample-andhold circuit. Experimental results point out the efficiency of both control strategies.