EPE Association: EPE 1985 - 30 - Lecture Session 5.5: HARMONICS AND REACTIVE POWER CONTROL

EPE 1985 - 30 - Lecture Session 5.5: HARMONICS AND REACTIVE POWER CONTROL
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 30 - Lecture Session 5.5: HARMONICS AND REACTIVE POWER CONTROL

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   METHODS TO IMPROVE THE POWER FACTOR IN SINGLE PHASE FED LOCOMOTIVES
By J. Bonal; E. Destobbeleer [View]
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Abstract: The power factor reflects the amplitude of the two simultaneous perturbations of the power supply of an electric railway locomotive: the creation of harmonic currents, and the consumption of reactive power. Generally, the input rectifier consists of two series-connected half-controlled bridges with sequential control. The authors present two methods improving the power factor:
- Connection of antiharmonic filters in parallel with the half-controlled bridges working with natura! commutation
- Use of bridges working with forced commutation and Pulse Width Modulation, with a very light input filter.
The necessary conditions which must be fulfilled by the filter capacitors, in order to effectively improve the power factor, are deduced.

   SPECTRAL OPTIMISATION OF PREDICTION FOR ARC FURNACE COMPENSATORS
By U. Ruckert; D. Schröder [View]
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Abstract: Compensating the reactive power of an arc furnace is considered. Up to now thyristor controlled reactors are used to reduce voltage fluctuations on powerlines. The insufficient dynamic behaviour of such compensation plants is discussed. Using the analysis of the reactive power signals of an arc furnace process, a new strategy of predictive control is presented. To improve the common compensation method a control system with a modified reactive power measurement and a predictor is used. Both parts, predictor and measurement system are adapted to the frequency range of human flicker sensitivity.

   IMPROVED SLIP POWER CONTROL ADDS PARAMOUNT QUALITY TO THE SLIP RECOVERY DRIVE
By Y. Mathisen [View]
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Abstract: Slip recovery drives are popular because they have low life-time cost. For limited ranges of speed control they represent one of the most cost-effective adjustable speed drives. By introducing an improved slip power control, some new qualities have been added to this type of drive. Non-torque producing circulating currents in the d.c. link are eliminated and it will be possible to maintain control over the drive during power supply disturbances. As a result of the improved control system, a number of application advantages such as savings in equipment size, operating losses, power consumption and production continuity are made available to the drive user.

   FILTERS FOR MINE THYRISTOR CONTROLLED LOCOMOTIVES WITH THE ALTERNATING CURRENT LINE FEED
By J. Machowski; R. Dabek [View]
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Abstract: The subject of this article is the analysis of the operation of a controllable, single-phase bridge, taking into consideration the parameters of the contact line feeding the locomotive. On the basis of this analysis, substantial voltage deformations in relation to the sinusoidal transient have been proved. These deformations have a negative influence on the operation of the other locomotives connected with the trolley line. In order to eliminate these deformations, a system of band filters has been suggested. By means of proper calculatoins, the current and voltage transients in the feeding system and in the locomotive have been determined. The mentioned filters enable to exclude the voltage deformations in the feeders and besides they exert an advantageous effect on the decrease of the voltage drop in this network. The present article is illustrated by diagrams obtained with the help of analytic calculations and oscillograms.

EPE 1985 - 30 - Lecture Session 5.5: HARMONICS AND REACTIVE POWER CONTROL
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1985 - Conference > EPE 1985 - 30 - Lecture Session 5.5: HARMONICS AND REACTIVE POWER CONTROL
	[return to parent folder]

	METHODS TO IMPROVE THE POWER FACTOR IN SINGLE PHASE FED LOCOMOTIVES By J. Bonal; E. Destobbeleer	[View] [Download]
Abstract: The power factor reflects the amplitude of the two simultaneous perturbations of the power supply of an electric railway locomotive: the creation of harmonic currents, and the consumption of reactive power. Generally, the input rectifier consists of two series-connected half-controlled bridges with sequential control. The authors present two methods improving the power factor: - Connection of antiharmonic filters in parallel with the half-controlled bridges working with natura! commutation - Use of bridges working with forced commutation and Pulse Width Modulation, with a very light input filter. The necessary conditions which must be fulfilled by the filter capacitors, in order to effectively improve the power factor, are deduced.

	SPECTRAL OPTIMISATION OF PREDICTION FOR ARC FURNACE COMPENSATORS By U. Ruckert; D. Schröder	[View] [Download]
Abstract: Compensating the reactive power of an arc furnace is considered. Up to now thyristor controlled reactors are used to reduce voltage fluctuations on powerlines. The insufficient dynamic behaviour of such compensation plants is discussed. Using the analysis of the reactive power signals of an arc furnace process, a new strategy of predictive control is presented. To improve the common compensation method a control system with a modified reactive power measurement and a predictor is used. Both parts, predictor and measurement system are adapted to the frequency range of human flicker sensitivity.

	IMPROVED SLIP POWER CONTROL ADDS PARAMOUNT QUALITY TO THE SLIP RECOVERY DRIVE By Y. Mathisen	[View] [Download]
Abstract: Slip recovery drives are popular because they have low life-time cost. For limited ranges of speed control they represent one of the most cost-effective adjustable speed drives. By introducing an improved slip power control, some new qualities have been added to this type of drive. Non-torque producing circulating currents in the d.c. link are eliminated and it will be possible to maintain control over the drive during power supply disturbances. As a result of the improved control system, a number of application advantages such as savings in equipment size, operating losses, power consumption and production continuity are made available to the drive user.

	FILTERS FOR MINE THYRISTOR CONTROLLED LOCOMOTIVES WITH THE ALTERNATING CURRENT LINE FEED By J. Machowski; R. Dabek	[View] [Download]
Abstract: The subject of this article is the analysis of the operation of a controllable, single-phase bridge, taking into consideration the parameters of the contact line feeding the locomotive. On the basis of this analysis, substantial voltage deformations in relation to the sinusoidal transient have been proved. These deformations have a negative influence on the operation of the other locomotives connected with the trolley line. In order to eliminate these deformations, a system of band filters has been suggested. By means of proper calculatoins, the current and voltage transients in the feeding system and in the locomotive have been determined. The mentioned filters enable to exclude the voltage deformations in the feeders and besides they exert an advantageous effect on the decrease of the voltage drop in this network. The present article is illustrated by diagrams obtained with the help of analytic calculations and oscillograms.