Conference Record of the 1992 IEEE Industry Applications Society Annual Meeting, 1992
The authors consider the design and implementation of active power filter systems based on concep... more The authors consider the design and implementation of active power filter systems based on concepts from variable structure systems (VSSs) and sliding mode control. The equivalent control concept from VSSs proves to be a very useful tool in the design of the filter. It is shown how the power circuit parameters are integrally tied to the equivalent control, and how circuit performance can be likewise judged. A design procedure is outlined using this approach. In addition, the authors discuss a closed-loop control for an active power filter based on a three-phase switchmode voltage-source inverter. The controller is composed of an inner current control loop which utilizes a sliding-mode control law, and an outer linear control loop which regulates the average voltage across the DC bus of the inverter. Simulations are presented to document converter performance
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Compu... more Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1988. Bibliography: v. 2, leaves 359-362. by David Allan Torrey. Ph.D.
Introduction These notes are o#ered to refresh your memory on some fundamental circuit analysis t... more Introduction These notes are o#ered to refresh your memory on some fundamental circuit analysis techniques. In particular, a review of reactive components and transformers is o#ered, followed by a brief review of time domain circuit analysis. The notes conclude with a discussion of some basic power concepts. The orientation of these notes is from the perspective of the power electronics engineer. That is, while these notes should not presentyou with any new material #I hope!#, they may present things in a way which is di#erent from the treatment given in an introductory circuits text. These notes are not intended to provide an exhaustive treatment of circuit analysis; see #1, 2# for a more complete treatment. 2 Circuit Components Semiconductor devices can be operated to change the shape of the voltage and currentwaveforms which are applied to a load. In power electronics we do this to e#ciently convert energy from one form to another. Semiconductor devices are no
The cost of the electronic drive for a switched-reluctance motor (SRM) is relatively high compare... more The cost of the electronic drive for a switched-reluctance motor (SRM) is relatively high compared to the SRM itself; this problem is common to most motor drives. However, since SRM torque production is independent of the direction of phase current, the phase excitation can be comprised of unipolar currents. This implies only one switching device per phase is needed. In addition, a high power quality utility interface can be accomplished with only two controllable switches. This paper details the design and operation of the SRM drive and its mating utility interface. The drive is fully regenerative and operates at high power factor with only four controllable switches.
ABSTRACT Recent years have seen a surge of interest in renewable energy sources. Most renewable e... more ABSTRACT Recent years have seen a surge of interest in renewable energy sources. Most renewable energy sources are intermittent in their production of power. One solution is to store the energy and draw from that stored energy in a controlled fashion. Recent advances have been made in solar thermal storage that would allow a solar thermal power system to operate year round and around the clock at nearly constant levels of electrical power production. This paper outlines how this can be accomplished.
APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285), 1999
ABSTRACT This paper presents a hybrid series passive/shunt active power filter system for high po... more ABSTRACT This paper presents a hybrid series passive/shunt active power filter system for high power nonlinear loads. This work is motivated by the limited ability of a power converter to perform effectively as an active filter by the power and the frequency distribution of the distortion for which it must compensate. The active filter system considered here is comprised of a three-phase shunt active filter and series AC line smoothing reactances installed in front of the target load. The proposed system significantly reduces the required shunt active filter bandwidth. The space-vector PWM controller for the active filter is based on a deadbeat control model. It is implemented digitally using a single 16-bit microcontroller. This controller requires only the supply current to be monitored, an approach different from conventional methods. The paper provides background on the operation of the filter, the details of the power circuit, the details of the control design, representative waveforms; and spectral performance for a filter which supports a 15 kVA phase controlled rectifier load. Experimental data indicate that the active filter typically consumes 2% or less of the average load power, suggesting that a parallel filter is an efficient compensation approach. The spectral performance shows that the active filter brings the system into compliance with IEEE 519-1992 up to the 33 rd harmonic for an AC line smoothing reactance of 0.13 p.u
Proceedings of 1994 IEEE Applied Power Electronics Conference and Exposition - ASPEC'94, 1994
This paper presents an active power filter for single-phase systems which are comprised of multip... more This paper presents an active power filter for single-phase systems which are comprised of multiple nonlinear loads. The active filter is based on a standard H-bridge inverter. The AC side of the inverter is connected in parallel with the other nonlinear loads through a filter inductance; the DC side of the inverter is connected to a filter capacitor. The inverter switches are controlled to shape the current through the filter inductor such that the line current is in phase with, and of the same shape as, the input voltage. Sliding-mode control is used to perform the active wave-shaping of the current. The paper provides the details of the power circuit design, the details of the control design, representative waveforms, and spectral performance for a filter which supports a 364 W AC controller and a 884 W uncontrolled bridge rectifier. Experimental data indicate that the active filter typically consumes 3% or less of the average load power, suggesting that a parallel filter is an efficient compensation approach. The spectral performance of the active filter easily meets the constraints of IEC555
2000 Power Engineering Society Summer Meeting (Cat. No.00CH37134), 2000
This paper reports the development of an active power line conditioner for high power nonlinear l... more This paper reports the development of an active power line conditioner for high power nonlinear loads such as industrial adjustable speed drives (ASDs). This work is motivated by the fact that the ability of a static power converter to perform effectively as a shunt active filter is limited by the power and the frequency distribution of the harmonics for which
IEE Proceedings - Electric Power Applications, 1995
ABSTRACT The paper presents models that connect the fundamental design of the variable reluctance... more ABSTRACT The paper presents models that connect the fundamental design of the variable reluctance machine (VRM) to an analytical expression the terminal magnetisation characteristics. The modelling procedure takes simple piecewise linear models which are based on the geometry and turns per phase of the VRM and maps them into an analytic terminal expression through a simple and fast algorithm. The piecewise linear and analytical expressions are based on physical reasoning. The modelling of three existing VRMs is presented, and the model predictions are compared with experiment. Simple models are shown to do an effective job of capturing the spatial and magnetic nonlinearities of the machine, thereby providing useful estimates of net and instantaneous machine performance. The analytic model is shown to compare favourably with another documented approach for the rapid description of VRM magnetisation characteristics
This paper presents active power filters for single-phase power systems which are comprised of mu... more This paper presents active power filters for single-phase power systems which are comprised of multiple nonlinear loads. The paper provides background on the operation of the filter, the details of the power circuit, the details of the control design, representative waveforms, and spectral performance for a filter which supports a 384 W AC controller and a 900 W uncontrolled bridge
This paper presents a hybrid series passive/shunt active power filter system for high power nonli... more This paper presents a hybrid series passive/shunt active power filter system for high power nonlinear loads. This work is motivated by the fact that the ability of a converter to perform effectively as an active filter is limited by the power and the frequency distribution of the distortion for which it must compensate. This system is comprised of a three-phase
... is two sections of twelve students each, made up of some combination of undergraduate and gra... more ... is two sections of twelve students each, made up of some combination of undergraduate and graduate ... Some sample project topics are given in Table I. The goal of the project is to have ... thereby leading them to a point where they are able to manage a power electronics project. ...
ABSTRACT This paper presents the design and implementation of a three-phase unity-power-factor si... more ABSTRACT This paper presents the design and implementation of a three-phase unity-power-factor single-stage ac-dc converter based on an interleaved flyback topology. The primary market target of the converter is within the telecommunications industry where it supplies high-quality dc power to the telecom loads and performs high-capacity battery charging while providing zero harmonic emission and unity power factor to the utility grid. The main design objective is to produce the lowest cost within a small-size system. The study includes mathematical analysis and simulation steps where the optimum number of cells to be interleaved and the associated phase shifts among the cells are determined while the emphasis being on the design of a perfectly coupled flyback transformer. Design of a transformer with the lowest leakage inductance and selection of components providing the lowest parasitic effects are critical for obtaining high efficiency and good performance. After the design is verified through simulation studies that uses Simulink and piecewise linear electrical circuit simulation model (PLECS) of the converter, a full-scale prototype is implemented to evaluate the performance of the design. In conclusion, experimental results demonstrate that converter works successfully and meets the commercialization expectations.
... An additional term is added to the inverter output current based on the change in utility ...... more ... An additional term is added to the inverter output current based on the change in utility ... algorithms have been proposed to control inverter output current for utility interactive opera-tions. ... feedforward compensation and decoupling, the linear model of the first order plant that we ...
Conference Record of the 1992 IEEE Industry Applications Society Annual Meeting, 1992
The authors consider the design and implementation of active power filter systems based on concep... more The authors consider the design and implementation of active power filter systems based on concepts from variable structure systems (VSSs) and sliding mode control. The equivalent control concept from VSSs proves to be a very useful tool in the design of the filter. It is shown how the power circuit parameters are integrally tied to the equivalent control, and how circuit performance can be likewise judged. A design procedure is outlined using this approach. In addition, the authors discuss a closed-loop control for an active power filter based on a three-phase switchmode voltage-source inverter. The controller is composed of an inner current control loop which utilizes a sliding-mode control law, and an outer linear control loop which regulates the average voltage across the DC bus of the inverter. Simulations are presented to document converter performance
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Compu... more Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1988. Bibliography: v. 2, leaves 359-362. by David Allan Torrey. Ph.D.
Introduction These notes are o#ered to refresh your memory on some fundamental circuit analysis t... more Introduction These notes are o#ered to refresh your memory on some fundamental circuit analysis techniques. In particular, a review of reactive components and transformers is o#ered, followed by a brief review of time domain circuit analysis. The notes conclude with a discussion of some basic power concepts. The orientation of these notes is from the perspective of the power electronics engineer. That is, while these notes should not presentyou with any new material #I hope!#, they may present things in a way which is di#erent from the treatment given in an introductory circuits text. These notes are not intended to provide an exhaustive treatment of circuit analysis; see #1, 2# for a more complete treatment. 2 Circuit Components Semiconductor devices can be operated to change the shape of the voltage and currentwaveforms which are applied to a load. In power electronics we do this to e#ciently convert energy from one form to another. Semiconductor devices are no
The cost of the electronic drive for a switched-reluctance motor (SRM) is relatively high compare... more The cost of the electronic drive for a switched-reluctance motor (SRM) is relatively high compared to the SRM itself; this problem is common to most motor drives. However, since SRM torque production is independent of the direction of phase current, the phase excitation can be comprised of unipolar currents. This implies only one switching device per phase is needed. In addition, a high power quality utility interface can be accomplished with only two controllable switches. This paper details the design and operation of the SRM drive and its mating utility interface. The drive is fully regenerative and operates at high power factor with only four controllable switches.
ABSTRACT Recent years have seen a surge of interest in renewable energy sources. Most renewable e... more ABSTRACT Recent years have seen a surge of interest in renewable energy sources. Most renewable energy sources are intermittent in their production of power. One solution is to store the energy and draw from that stored energy in a controlled fashion. Recent advances have been made in solar thermal storage that would allow a solar thermal power system to operate year round and around the clock at nearly constant levels of electrical power production. This paper outlines how this can be accomplished.
APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285), 1999
ABSTRACT This paper presents a hybrid series passive/shunt active power filter system for high po... more ABSTRACT This paper presents a hybrid series passive/shunt active power filter system for high power nonlinear loads. This work is motivated by the limited ability of a power converter to perform effectively as an active filter by the power and the frequency distribution of the distortion for which it must compensate. The active filter system considered here is comprised of a three-phase shunt active filter and series AC line smoothing reactances installed in front of the target load. The proposed system significantly reduces the required shunt active filter bandwidth. The space-vector PWM controller for the active filter is based on a deadbeat control model. It is implemented digitally using a single 16-bit microcontroller. This controller requires only the supply current to be monitored, an approach different from conventional methods. The paper provides background on the operation of the filter, the details of the power circuit, the details of the control design, representative waveforms; and spectral performance for a filter which supports a 15 kVA phase controlled rectifier load. Experimental data indicate that the active filter typically consumes 2% or less of the average load power, suggesting that a parallel filter is an efficient compensation approach. The spectral performance shows that the active filter brings the system into compliance with IEEE 519-1992 up to the 33 rd harmonic for an AC line smoothing reactance of 0.13 p.u
Proceedings of 1994 IEEE Applied Power Electronics Conference and Exposition - ASPEC'94, 1994
This paper presents an active power filter for single-phase systems which are comprised of multip... more This paper presents an active power filter for single-phase systems which are comprised of multiple nonlinear loads. The active filter is based on a standard H-bridge inverter. The AC side of the inverter is connected in parallel with the other nonlinear loads through a filter inductance; the DC side of the inverter is connected to a filter capacitor. The inverter switches are controlled to shape the current through the filter inductor such that the line current is in phase with, and of the same shape as, the input voltage. Sliding-mode control is used to perform the active wave-shaping of the current. The paper provides the details of the power circuit design, the details of the control design, representative waveforms, and spectral performance for a filter which supports a 364 W AC controller and a 884 W uncontrolled bridge rectifier. Experimental data indicate that the active filter typically consumes 3% or less of the average load power, suggesting that a parallel filter is an efficient compensation approach. The spectral performance of the active filter easily meets the constraints of IEC555
2000 Power Engineering Society Summer Meeting (Cat. No.00CH37134), 2000
This paper reports the development of an active power line conditioner for high power nonlinear l... more This paper reports the development of an active power line conditioner for high power nonlinear loads such as industrial adjustable speed drives (ASDs). This work is motivated by the fact that the ability of a static power converter to perform effectively as a shunt active filter is limited by the power and the frequency distribution of the harmonics for which
IEE Proceedings - Electric Power Applications, 1995
ABSTRACT The paper presents models that connect the fundamental design of the variable reluctance... more ABSTRACT The paper presents models that connect the fundamental design of the variable reluctance machine (VRM) to an analytical expression the terminal magnetisation characteristics. The modelling procedure takes simple piecewise linear models which are based on the geometry and turns per phase of the VRM and maps them into an analytic terminal expression through a simple and fast algorithm. The piecewise linear and analytical expressions are based on physical reasoning. The modelling of three existing VRMs is presented, and the model predictions are compared with experiment. Simple models are shown to do an effective job of capturing the spatial and magnetic nonlinearities of the machine, thereby providing useful estimates of net and instantaneous machine performance. The analytic model is shown to compare favourably with another documented approach for the rapid description of VRM magnetisation characteristics
This paper presents active power filters for single-phase power systems which are comprised of mu... more This paper presents active power filters for single-phase power systems which are comprised of multiple nonlinear loads. The paper provides background on the operation of the filter, the details of the power circuit, the details of the control design, representative waveforms, and spectral performance for a filter which supports a 384 W AC controller and a 900 W uncontrolled bridge
This paper presents a hybrid series passive/shunt active power filter system for high power nonli... more This paper presents a hybrid series passive/shunt active power filter system for high power nonlinear loads. This work is motivated by the fact that the ability of a converter to perform effectively as an active filter is limited by the power and the frequency distribution of the distortion for which it must compensate. This system is comprised of a three-phase
... is two sections of twelve students each, made up of some combination of undergraduate and gra... more ... is two sections of twelve students each, made up of some combination of undergraduate and graduate ... Some sample project topics are given in Table I. The goal of the project is to have ... thereby leading them to a point where they are able to manage a power electronics project. ...
ABSTRACT This paper presents the design and implementation of a three-phase unity-power-factor si... more ABSTRACT This paper presents the design and implementation of a three-phase unity-power-factor single-stage ac-dc converter based on an interleaved flyback topology. The primary market target of the converter is within the telecommunications industry where it supplies high-quality dc power to the telecom loads and performs high-capacity battery charging while providing zero harmonic emission and unity power factor to the utility grid. The main design objective is to produce the lowest cost within a small-size system. The study includes mathematical analysis and simulation steps where the optimum number of cells to be interleaved and the associated phase shifts among the cells are determined while the emphasis being on the design of a perfectly coupled flyback transformer. Design of a transformer with the lowest leakage inductance and selection of components providing the lowest parasitic effects are critical for obtaining high efficiency and good performance. After the design is verified through simulation studies that uses Simulink and piecewise linear electrical circuit simulation model (PLECS) of the converter, a full-scale prototype is implemented to evaluate the performance of the design. In conclusion, experimental results demonstrate that converter works successfully and meets the commercialization expectations.
... An additional term is added to the inverter output current based on the change in utility ...... more ... An additional term is added to the inverter output current based on the change in utility ... algorithms have been proposed to control inverter output current for utility interactive opera-tions. ... feedforward compensation and decoupling, the linear model of the first order plant that we ...
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Papers by David Torrey