EPE Association: EPE 1995 - 12 - Lecture Session L3d: REACTIVE POWER COMPENSATION AND POWER FACTOR CORRECTION

EPE 1995 - 12 - Lecture Session L3d: REACTIVE POWER COMPENSATION AND POWER FACTOR CORRECTION
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 12 - Lecture Session L3d: REACTIVE POWER COMPENSATION AND POWER FACTOR CORRECTION

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   INTRODUCTION OF "DUAL-SWITCHING" CELLES IN HIGH POWER PHASE-CONTROLLED CONVERTERS - A NEW CONCEPT TO CANCEL THE REACTIVE POWER
By F. Richardeau; Ph. Ladoux; Y. Cheron [View]
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Abstract: High power converters (MW) use thyristors arrangements in phase-controlled mode by the voltages of the power supply network. However, low-rank harmonic currents and lagging reachtive power are drawn on AC side. In this paper, a new "dual-switching" mode with GTOs switches reverse blocking capabilities is studied and carried out in basic rectifier bridges and naturally commutated cycloconverter topologies. This concept allows to cancel the reactive power flow between power supply network and direct converters whatever load parameters. Global features are given with a final comparison list, especially on following "dual-switching" topologies: full-bridge cycloconverter, mixed-bridge cycloconverter and series arrangement of full-bridges cycloconverter. Presented experimental results are based on a 20 kVA versatile cycloconverter prototype and confirm the theoretical study. These topologies are expected for a better matching between network and high power converters.

   THE ENERGY FACTOR IN INDUCTION HEATING SYSTEMS
By J.R. Garcia; A. Martinez [View]
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Abstract: This work gives an answer to important questions usually asked in induction heating designs: Given a coil and a workpiece: Which are the optimum parameters (frequency and coil-Workpiece geometry) to heat this system? To answer this question an Energy Factor (EF) is defined in electromagnetic and in circuital terms. With this factor it is possible to obtain the transfer power efficiency between the coil and the workpiece. Analytical and calculated results are provided for verification.

   CONTAINERIZED SVCS - A NOVEL DESIGN
By K. Renz; H. Tyll; G. Thumm [View]
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Abstract: Static VAr Compensators (SVC) have been successfully used for many years to improve the operation of high-voltage transmission networks under severe conditions. The main applications are fast voltage control and damping of power oscillations to allow enhanced power transfer thus making better use of the power system. Fast implementation of the Jember SVC (Indonesia) was required to ensure safe system operation within shortest time. To achieve the short lead time of only 12 months a novel SVC design was needed. The novel SVC design is based on containerization to the largest extend possible. The thyristor valves, their cooling equipment, the SVC controls and protection as well as AC and DC distribution are included in the container. Using out-door valves in an SVC application required careful design. The special ambient conditions of the tropical site had to be taken into account. The containerized design allows for prefabrication, pre-installation and pre-commissioning of the SVC system at the manufacturer's workshop and reducing installation and commissioning time at site. This technique opens the road for transportable SVCs which may be easily and economically relocatable. This feature offers a new flexibility for rapidly growing countries with increasing power demands or in countries with suddenly changing system operation philosophy. In the past it frequently used to be necessary to install an extra SVC. With the new container-type design of SVC this, in many, instances, is no longer necessary.

   MODELLING AND SIMULATION OF STATIC VAR COMPENSATORS FOR CONTROL
By K.M. Abbott; M. Davies [View]
[Download]

Abstract: Modelling and simulation of Static-V AR Compensators (SVC) is explored with a view to achieving good transient performance by appropriate controller design. Time and frequency domain mathematical computer models are developed which are verified using hardware laboratory equipment. The paper demonstrates how the transient envelope of the AC system may be extracted and the underlying system dynamics identified. Using this information appropriate control system design is achieved.

EPE 1995 - 12 - Lecture Session L3d: REACTIVE POWER COMPENSATION AND POWER FACTOR CORRECTION
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 12 - Lecture Session L3d: REACTIVE POWER COMPENSATION AND POWER FACTOR CORRECTION
	[return to parent folder]

	INTRODUCTION OF "DUAL-SWITCHING" CELLES IN HIGH POWER PHASE-CONTROLLED CONVERTERS - A NEW CONCEPT TO CANCEL THE REACTIVE POWER By F. Richardeau; Ph. Ladoux; Y. Cheron	[View] [Download]
Abstract: High power converters (MW) use thyristors arrangements in phase-controlled mode by the voltages of the power supply network. However, low-rank harmonic currents and lagging reachtive power are drawn on AC side. In this paper, a new "dual-switching" mode with GTOs switches reverse blocking capabilities is studied and carried out in basic rectifier bridges and naturally commutated cycloconverter topologies. This concept allows to cancel the reactive power flow between power supply network and direct converters whatever load parameters. Global features are given with a final comparison list, especially on following "dual-switching" topologies: full-bridge cycloconverter, mixed-bridge cycloconverter and series arrangement of full-bridges cycloconverter. Presented experimental results are based on a 20 kVA versatile cycloconverter prototype and confirm the theoretical study. These topologies are expected for a better matching between network and high power converters.

	THE ENERGY FACTOR IN INDUCTION HEATING SYSTEMS By J.R. Garcia; A. Martinez	[View] [Download]
Abstract: This work gives an answer to important questions usually asked in induction heating designs: Given a coil and a workpiece: Which are the optimum parameters (frequency and coil-Workpiece geometry) to heat this system? To answer this question an Energy Factor (EF) is defined in electromagnetic and in circuital terms. With this factor it is possible to obtain the transfer power efficiency between the coil and the workpiece. Analytical and calculated results are provided for verification.

	CONTAINERIZED SVCS - A NOVEL DESIGN By K. Renz; H. Tyll; G. Thumm	[View] [Download]
Abstract: Static VAr Compensators (SVC) have been successfully used for many years to improve the operation of high-voltage transmission networks under severe conditions. The main applications are fast voltage control and damping of power oscillations to allow enhanced power transfer thus making better use of the power system. Fast implementation of the Jember SVC (Indonesia) was required to ensure safe system operation within shortest time. To achieve the short lead time of only 12 months a novel SVC design was needed. The novel SVC design is based on containerization to the largest extend possible. The thyristor valves, their cooling equipment, the SVC controls and protection as well as AC and DC distribution are included in the container. Using out-door valves in an SVC application required careful design. The special ambient conditions of the tropical site had to be taken into account. The containerized design allows for prefabrication, pre-installation and pre-commissioning of the SVC system at the manufacturer's workshop and reducing installation and commissioning time at site. This technique opens the road for transportable SVCs which may be easily and economically relocatable. This feature offers a new flexibility for rapidly growing countries with increasing power demands or in countries with suddenly changing system operation philosophy. In the past it frequently used to be necessary to install an extra SVC. With the new container-type design of SVC this, in many, instances, is no longer necessary.

	MODELLING AND SIMULATION OF STATIC VAR COMPENSATORS FOR CONTROL By K.M. Abbott; M. Davies	[View] [Download]
Abstract: Modelling and simulation of Static-V AR Compensators (SVC) is explored with a view to achieving good transient performance by appropriate controller design. Time and frequency domain mathematical computer models are developed which are verified using hardware laboratory equipment. The paper demonstrates how the transient envelope of the AC system may be extracted and the underlying system dynamics identified. Using this information appropriate control system design is achieved.