EPE Association: EPE 1995 - 46 - Dialogue Session DS6b: Control (III)

EPE 1995 - 46 - Dialogue Session DS6b: Control (III)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 46 - Dialogue Session DS6b: Control (III)

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   A NEW APPROACH FOR SYNTHESIZING LOGIC CONNECTION CONTROLLERS IN POWER CONVERTERS
By B. Francois; J. P. Cambronne; J. P. Hautier [View]
[Download]

Abstract: A particular analysis of dependencies between the switch states and the wished conversion level of three phases converters is detailed. A design of a logic interface between these variables is deduced. Similarities with the interface design of the dual structure point out the synthesis of a logic commutations controller.

   A SIMULATION TOOL FOR THE CONTROL OF A HYBRID DYNAMICAL SYSTEM APPLICATION TO ELECTRICAL DRIVES
By C. Zanne; F. Ibrahim; C. Iung [View]
[Download]

Abstract: This article describes a feasibility study of the validation, by device simulation (process and control), of the specification sheet of the control system of a electrical drive, after its normalization. lt deals specifically with the problem of computing time and of the accuracy of event detection, offers a solution, and presents the obtained results.

   A CONTROL METHOD FOR A GENERALISED CONVERTER USING INSTANTANEOUS VALUES OF PHASE VOLTAGES
By S. Bouchiker; G. A. Capolino; M. Poloujadoff [View]
[Download]

Abstract: This paper describes a control method based on using instantaneous phase voltages to generate the modulation fonctions needed to operate a direct frequency changer (AC-AC) using bidirectional switches operating at high frequency. The advantages are minimal low order harmonics, sinusoïdal waveforms, bidirectionality, separate control over amplitude, frequency, phase, and power factor. Moreover, the converter operation can be set to produce almost any power displacement factor, independent of load power factor. The paper presents basic theory and simulation results showing the unified algorithm in operation.

   RECOVERY OF AN INVERTING MODE COMMUTATION FAILURE IN THE CASE OF A THREE PHASE D.C. THYRISTOR BRIDGE CONTROLLED BY A DIGITAL DEVICE
By J-P. Sawicki; J-F. Aubry; C. Zanne [View]
[Download]

Abstract: In this paper, we present a strategy to recover commutation failures in nonautonomous inverting mode. We intend to improve the performances of any electromechanical process working in this mode while warranting its dependability. Steady states like transient events, normal or faulty, are described accurately with the help of state graph. A firing sequence reconfiguration is deduced from all the possibilities to switch on thyristors in the static converter. The recovery strategy is tested on a bench composed of two D.C machines : the side effects of the procedure are minimized in delaying the recovery pair and in resetting properly the armature current controller.

   SELF TUNING TIME OPTIMAL ALGORITHM FOR THYRISTOR CONVERTER CURRENT CONTROL
By Stjepan Bogdan; Zdenko Kovacic; Petar Crnosija [View]
[Download]

Abstract: A linear dead beat algorithm applied to the current. control of a thyristor converter loaded with a DC motor is described. A very simple algorithm for estimation of the thyristor converter gain coefficient has been developed. Based on the estimated gain coefficient value, adaptation algorithms which perform the self-tuning of the dead beat algorithm coefficients have been developed. The usage of the proposed algorithms ensures that transient response of thyristor converter current is completed within a single current pulsation both in the continuous and the discontinuous mode of conduction.

   THE SYNTHESIS OF CONVERTERS CONTROL WITH MAXIMUM SPEED OF RESPONSE
By A. S. Iskhakov; N. V. Dedkov; S. Y. Serov [View]
[Download]

Abstract: The paper presents a new control method of power supplies on base of pulsed voltage converters. A major advantage of this method is that it allows to attain a maximum speed of response both for small and high deviations from a steady-state regime. An action principile of this method is explained by giving an example of the pulse width modulator. Considerable advantage in the speed of response of the new regulators in comparison with classical regulators gives a base to suppose that they can obtain wide application.

   AN UNCONVENTIONAL NO-CONSTANT FREQUENCY MODULATION STRATEGY FOR STATIC CONVERTERS
By P. Bolognesi; G. Carrara; D. Casini; L. Taponecco [View]
[Download]

Abstract: A modulation strategy for the control of the converter switches, that operates on small time portions of the reference signal, and is alternative to the PWM traditional methods, is proposed. This strategy, based on the local equivalence of one of the harmonic components (e.g. the mean values or fundamentals) and characterised by a no-constant frequency modulation, takes into account the constraint of the minimum time between two successive commutations introduced by the real switching components and seems to be interesting from the point of view of pulse dropping, acoustic noise, etc. An analysis concerning the theoretical bases of the local spectral approximation strategy is carried out and the potentialities of this strategy are highlighted. Sorne approximation techniques based on the proposed strategy and some simulation results are reported.

   CONTROL OF CONTINUOUS-MODE BOOST-CONVERTERS IN A UNITY POWER FACTOR RECTIFIER
By I. Merfert; H. Mecke [View]
[Download]

Abstract: Most of the unity power factor rectifiers need a current control loop to realize sinusoïdal mains current. This paper deals with an approach of achieving sinusoïdal mains current of continuous-mode boost converters by controlling their Dc-output voltage only.

   Reduced Reactive Power Grid Connection with on-line Compensation of Current Harmonics
By G. Berger; J. Buettner; J. Petzoldt; M. Schilling [View]
[Download]

Abstract: The presented converter system is an electrical appliance for realizing a sinusoïdal main current with on-line compensation of harmonies even when the load characteristic is quite reactive and the load current includes a lot of harmonies with high amplitudes e.g. a rectifier load. The proposed method is able to avoid the fundamental reactive power and to reduce extremly the current harmonies, especially the 5-th and the 7-th (less than 1 %).

   EFFICIENCY OPTIMISATION IN CURRENT CONTROLLED VARIABLE-SPEED SWITCHED RELUCTANCE MOTOR DRIVES
By P. C. Kjaer; F. Blaabjerg; C. Cossar; T. J. E. Miller [View]
[Download]

Abstract: This paper describes a new Efficiency Optimisation Algorithm for variable-speed Switched Reluctance Motor drives operated in current control. A thorough analysis of the average torque production in current controlled SR drives is made with respect to the parameters current reference, angular velocity and firing angles. It is shown that a true optimum efficiency can be found using the tum-off angle in a slow control loop, while operating with a faster closed-loop speed control. The power flow is measured and minimised in the DC-link, while the speed controller maintains a constant output power. Simulation results show up to 6% gain in efficiency. Test results show on-line efficiency maximisation without loosing dynamic performance. They also show that a global minimum is reached by the on-line search. The method established is completely independent of the machine topology and operating conditions, and as such applicable to any current controlled variable-speed Switched Reluctance Motor drive.

   A VOLTAGE MODE CONTROL STRATEGY FOR PARALLEL POWER CONVERTERS WITH CURRENT SHARING
By A. Lago; C. M. Penalver; J. Marcos [View]
[Download]

Abstract: High power supply systems must be carefully designed in order to maintain their performance, compared to that of low power systems. There is a trend to use several standard DC-DC converters connected in parallel to solve this problem. These converters help to reduce the costs and to improve the productivity in the facilites where they are used. This paper describes two methods to connect several DC-DC power converters to form a high power supply system so that they achieve the basic requirements of this system. The "averaged voltage mode control" and the new method "synchronized voltage mode control" permit to share the total load current of the power supply system equally between the different power modules using voltage mode control. Both methods are compared with classical methods in the case of three buck converters (12V,5A) connected in parallel operation. The system has been simulated using the PSPICE V4.02 of MicroSim Corporation. For the synchronized voltage mode control, the simulated results are compared with experimental results.

   METHODS TO IMPROVE DYNAMIC RESPONSE OF POWER FACTOR PREREGULATORS: AN OVERVIEW
By G. Spiazzi; P. Mattavelli; L. Rossetto [View]
[Download]

Abstract: ln standard Power Factor Preregulators (PFP's), there is a trade-off between output voltage dynamic and input current distortion. ln this paper, several control techniques aimed to improve the output voltage transient response of Power Factor Preregulators (PFP's) while maintaining a high power factor are reviewed and compared. These methods do not require additional sensing, but only simple analog circuitry, and work with wide input voltage range. Simulation tests on a Boost converter with average current control highlight merits and drawbacks of each solution.

   ANALYSIS OF SPECTRAL PERFORMANCE OF RESONANT DC LINK INVERTER CONTROLLED BY DELTA-SIGMA MODULATION
By R. Uhrin; F. Profumo [View]
[Download]

Abstract: In the paper spectral performance of the first and second order Delta-Sigma modulators used in Resonant DC Link Inverters is investigated. The approach taken to derive the modulator specta is based on the assumption that quantization error from the regularly sampled modulator can be treated as a white noise. The modulator performance is also compared in terms of voltage and current harmonic distortion with the PWM modulated hard switched inverter.

EPE 1995 - 46 - Dialogue Session DS6b: Control (III)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 46 - Dialogue Session DS6b: Control (III)
	[return to parent folder]

	A NEW APPROACH FOR SYNTHESIZING LOGIC CONNECTION CONTROLLERS IN POWER CONVERTERS By B. Francois; J. P. Cambronne; J. P. Hautier	[View] [Download]
Abstract: A particular analysis of dependencies between the switch states and the wished conversion level of three phases converters is detailed. A design of a logic interface between these variables is deduced. Similarities with the interface design of the dual structure point out the synthesis of a logic commutations controller.

	A SIMULATION TOOL FOR THE CONTROL OF A HYBRID DYNAMICAL SYSTEM APPLICATION TO ELECTRICAL DRIVES By C. Zanne; F. Ibrahim; C. Iung	[View] [Download]
Abstract: This article describes a feasibility study of the validation, by device simulation (process and control), of the specification sheet of the control system of a electrical drive, after its normalization. lt deals specifically with the problem of computing time and of the accuracy of event detection, offers a solution, and presents the obtained results.

	A CONTROL METHOD FOR A GENERALISED CONVERTER USING INSTANTANEOUS VALUES OF PHASE VOLTAGES By S. Bouchiker; G. A. Capolino; M. Poloujadoff	[View] [Download]
Abstract: This paper describes a control method based on using instantaneous phase voltages to generate the modulation fonctions needed to operate a direct frequency changer (AC-AC) using bidirectional switches operating at high frequency. The advantages are minimal low order harmonics, sinusoïdal waveforms, bidirectionality, separate control over amplitude, frequency, phase, and power factor. Moreover, the converter operation can be set to produce almost any power displacement factor, independent of load power factor. The paper presents basic theory and simulation results showing the unified algorithm in operation.

	RECOVERY OF AN INVERTING MODE COMMUTATION FAILURE IN THE CASE OF A THREE PHASE D.C. THYRISTOR BRIDGE CONTROLLED BY A DIGITAL DEVICE By J-P. Sawicki; J-F. Aubry; C. Zanne	[View] [Download]
Abstract: In this paper, we present a strategy to recover commutation failures in nonautonomous inverting mode. We intend to improve the performances of any electromechanical process working in this mode while warranting its dependability. Steady states like transient events, normal or faulty, are described accurately with the help of state graph. A firing sequence reconfiguration is deduced from all the possibilities to switch on thyristors in the static converter. The recovery strategy is tested on a bench composed of two D.C machines : the side effects of the procedure are minimized in delaying the recovery pair and in resetting properly the armature current controller.

	SELF TUNING TIME OPTIMAL ALGORITHM FOR THYRISTOR CONVERTER CURRENT CONTROL By Stjepan Bogdan; Zdenko Kovacic; Petar Crnosija	[View] [Download]
Abstract: A linear dead beat algorithm applied to the current. control of a thyristor converter loaded with a DC motor is described. A very simple algorithm for estimation of the thyristor converter gain coefficient has been developed. Based on the estimated gain coefficient value, adaptation algorithms which perform the self-tuning of the dead beat algorithm coefficients have been developed. The usage of the proposed algorithms ensures that transient response of thyristor converter current is completed within a single current pulsation both in the continuous and the discontinuous mode of conduction.

	THE SYNTHESIS OF CONVERTERS CONTROL WITH MAXIMUM SPEED OF RESPONSE By A. S. Iskhakov; N. V. Dedkov; S. Y. Serov	[View] [Download]
Abstract: The paper presents a new control method of power supplies on base of pulsed voltage converters. A major advantage of this method is that it allows to attain a maximum speed of response both for small and high deviations from a steady-state regime. An action principile of this method is explained by giving an example of the pulse width modulator. Considerable advantage in the speed of response of the new regulators in comparison with classical regulators gives a base to suppose that they can obtain wide application.

	AN UNCONVENTIONAL NO-CONSTANT FREQUENCY MODULATION STRATEGY FOR STATIC CONVERTERS By P. Bolognesi; G. Carrara; D. Casini; L. Taponecco	[View] [Download]
Abstract: A modulation strategy for the control of the converter switches, that operates on small time portions of the reference signal, and is alternative to the PWM traditional methods, is proposed. This strategy, based on the local equivalence of one of the harmonic components (e.g. the mean values or fundamentals) and characterised by a no-constant frequency modulation, takes into account the constraint of the minimum time between two successive commutations introduced by the real switching components and seems to be interesting from the point of view of pulse dropping, acoustic noise, etc. An analysis concerning the theoretical bases of the local spectral approximation strategy is carried out and the potentialities of this strategy are highlighted. Sorne approximation techniques based on the proposed strategy and some simulation results are reported.

	CONTROL OF CONTINUOUS-MODE BOOST-CONVERTERS IN A UNITY POWER FACTOR RECTIFIER By I. Merfert; H. Mecke	[View] [Download]
Abstract: Most of the unity power factor rectifiers need a current control loop to realize sinusoïdal mains current. This paper deals with an approach of achieving sinusoïdal mains current of continuous-mode boost converters by controlling their Dc-output voltage only.

	Reduced Reactive Power Grid Connection with on-line Compensation of Current Harmonics By G. Berger; J. Buettner; J. Petzoldt; M. Schilling	[View] [Download]
Abstract: The presented converter system is an electrical appliance for realizing a sinusoïdal main current with on-line compensation of harmonies even when the load characteristic is quite reactive and the load current includes a lot of harmonies with high amplitudes e.g. a rectifier load. The proposed method is able to avoid the fundamental reactive power and to reduce extremly the current harmonies, especially the 5-th and the 7-th (less than 1 %).

	EFFICIENCY OPTIMISATION IN CURRENT CONTROLLED VARIABLE-SPEED SWITCHED RELUCTANCE MOTOR DRIVES By P. C. Kjaer; F. Blaabjerg; C. Cossar; T. J. E. Miller	[View] [Download]
Abstract: This paper describes a new Efficiency Optimisation Algorithm for variable-speed Switched Reluctance Motor drives operated in current control. A thorough analysis of the average torque production in current controlled SR drives is made with respect to the parameters current reference, angular velocity and firing angles. It is shown that a true optimum efficiency can be found using the tum-off angle in a slow control loop, while operating with a faster closed-loop speed control. The power flow is measured and minimised in the DC-link, while the speed controller maintains a constant output power. Simulation results show up to 6% gain in efficiency. Test results show on-line efficiency maximisation without loosing dynamic performance. They also show that a global minimum is reached by the on-line search. The method established is completely independent of the machine topology and operating conditions, and as such applicable to any current controlled variable-speed Switched Reluctance Motor drive.

	A VOLTAGE MODE CONTROL STRATEGY FOR PARALLEL POWER CONVERTERS WITH CURRENT SHARING By A. Lago; C. M. Penalver; J. Marcos	[View] [Download]
Abstract: High power supply systems must be carefully designed in order to maintain their performance, compared to that of low power systems. There is a trend to use several standard DC-DC converters connected in parallel to solve this problem. These converters help to reduce the costs and to improve the productivity in the facilites where they are used. This paper describes two methods to connect several DC-DC power converters to form a high power supply system so that they achieve the basic requirements of this system. The "averaged voltage mode control" and the new method "synchronized voltage mode control" permit to share the total load current of the power supply system equally between the different power modules using voltage mode control. Both methods are compared with classical methods in the case of three buck converters (12V,5A) connected in parallel operation. The system has been simulated using the PSPICE V4.02 of MicroSim Corporation. For the synchronized voltage mode control, the simulated results are compared with experimental results.

	METHODS TO IMPROVE DYNAMIC RESPONSE OF POWER FACTOR PREREGULATORS: AN OVERVIEW By G. Spiazzi; P. Mattavelli; L. Rossetto	[View] [Download]
Abstract: ln standard Power Factor Preregulators (PFP's), there is a trade-off between output voltage dynamic and input current distortion. ln this paper, several control techniques aimed to improve the output voltage transient response of Power Factor Preregulators (PFP's) while maintaining a high power factor are reviewed and compared. These methods do not require additional sensing, but only simple analog circuitry, and work with wide input voltage range. Simulation tests on a Boost converter with average current control highlight merits and drawbacks of each solution.

	ANALYSIS OF SPECTRAL PERFORMANCE OF RESONANT DC LINK INVERTER CONTROLLED BY DELTA-SIGMA MODULATION By R. Uhrin; F. Profumo	[View] [Download]
Abstract: In the paper spectral performance of the first and second order Delta-Sigma modulators used in Resonant DC Link Inverters is investigated. The approach taken to derive the modulator specta is based on the assumption that quantization error from the regularly sampled modulator can be treated as a white noise. The modulator performance is also compared in terms of voltage and current harmonic distortion with the PWM modulated hard switched inverter.