The Experts below are selected from a list of 31482 Experts worldwide ranked by ideXlab platform
K M Smedley - One of the best experts on this subject based on the ideXlab platform.
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one cycle controlled three phase grid connected inverters and their parallel Operation
IEEE Transactions on Industry Applications, 2008Co-Authors: Yang Chen, K M SmedleyAbstract:Grid-connected inverters are necessary for converting the DC power generated by photovoltaic or fuel cells to the AC power of the utility grid. Parallel Operation of these inverters extends the power range to a much higher level and allows modular design. This paper studies current sharing and circulating current among paralleled inverter modules and proposes a new parallel Operation method based on one-cycle control (OCC) with combined Vector Operation and bipolar Operation. With some minor additions to the original OCC circuit and a simple add-on communication path among the individual modules, the current is properly shared among all the inverters and the circulating current is limited to an acceptable range, while OCC advantages such as constant switching frequency, no multipliers, and simple circuitry are preserved. Two OCC inverters of 1.5 kW each were built and tied together using the proposed parallel Operation. Experiments were conducted to demonstrate the simplicity and effectiveness of this method.
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parallel Operation of one cycle controlled three phase pfc rectifiers
IEEE Transactions on Industrial Electronics, 2007Co-Authors: Yang Chen, K M SmedleyAbstract:Parallel Operation of three-phase power-factor-corrected (PFC) rectifiers is a critical issue for high-power applications, since it extends the power range to a much higher level and allows modular design. The technical challenges are current sharing and circulating current control among the modules. This paper studies these phenomena within two paralleled rectifiers and proposes a new current-sharing method based on one-cycle control (OCC) with Vector Operation and bipolar Operation. With some minor additions to the original OCC circuit and a simple add-on communication path among the individual modules, the input current is shared and the circulating current is limited, while the OCC advantages, such as constant switching frequency, no multipliers, and simple circuitry, are preserved. Two OCC PFC rectifiers of 2.5 kW each were built and tied together using the proposed parallel Operation method. Experiments have demonstrated the simplicity and the effectiveness of this method.
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steady state and dynamic study of one cycle controlled three phase power factor correction
IEEE Transactions on Industrial Electronics, 2005Co-Authors: Guozhu Chen, K M SmedleyAbstract:One-cycle control power-factor correction (OCC-PFC) with Vector Operation is a promising rectification method that eliminates harmonics and improves the power factor. It features great simplicity, high performance, and excellent stability. This paper performs analysis and design of OCC-PFC in both the steady-state and dynamic transients. The sufficient stability condition for three-phase OCC-PFC is derived. Some typical large-signal perturbations in practice are then used to verify the theoretical predictions. The paper also provides some guidelines for the selection of the circuit parameters in practical application. All analysis results were verified by simulation or experiments based on a three-phase 1-kW pre-industrial OCC-PFC prototype.
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parallel Operation of one cycle controlled three phase pfc rectifiers
Applied Power Electronics Conference, 2005Co-Authors: Yang Chen, K M SmedleyAbstract:Parallel Operation of three-phase power factor corrected (PFC) rectifiers extends the power range to a much higher level and allows modular design. However, circulating current among the modules could be a potential problem. This paper studies the circulating current phenomenon within two paralleled rectifiers and proposes a new current sharing method based on one-cycle control with Vector Operation and bipolar Operation. With some minor addition to the original one-cycle control circuit and a simple add-on communication path among the individual modules, the circulating current is eliminated, while the OCC advantages, such as constant switching frequency, no multipliers, and simple circuitry, are preserved. Two one-cycle controlled rectifiers of 2.5 kW each were built and tied together using the proposed parallel Operation method. Experiments have shown the simplicity and the effectiveness of this method.
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one cycle control of three phase active power filter with Vector Operation
IEEE Transactions on Industrial Electronics, 2004Co-Authors: Chongming Qiao, K M SmedleyAbstract:Active power filters (APFs) provides an effective measure to eliminate the power line harmonic/reactive currents generated by nonlinear loads or by distributed energy sources that are connected to the grid. Active power filters are typically connected in parallel to the harmonic/reactive current sources and cancel the harmonic/reactive components in the line current so that the current flow into and from the grid is sinusoidal and in phase with the grid voltage. Since the APFs process only the harmonic/reactive power, their power-handling capability can be much higher than that of the cascade power-factor-correction methods. In this paper, the one-cycle control method is extended to control three-phase APFs. The proposed control approach employs one integrator with reset along with several logic and linear components to control a voltage-source converter to achieve three-phase unity power factor for the current to and from the power grid. No multipliers or sensors for the load current and the APF inductor current are required. Furthermore, there is no need to calculate the reference for controlling APF inductor current so that complicated digital computation is eliminated. The Operation switching frequency is constant that is desirable for industrial applications. The proposed control approach features great simplicity, excellent harmonic/reactive current cancellation, and solid stability. It is a cost-effective solution for power quality control for electronic equipment, buildings, industrial facilities, ships, airplanes, distributed power generation stations, etc. All findings are supported by experimental results.
Yang Chen - One of the best experts on this subject based on the ideXlab platform.
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one cycle controlled three phase grid connected inverters and their parallel Operation
IEEE Transactions on Industry Applications, 2008Co-Authors: Yang Chen, K M SmedleyAbstract:Grid-connected inverters are necessary for converting the DC power generated by photovoltaic or fuel cells to the AC power of the utility grid. Parallel Operation of these inverters extends the power range to a much higher level and allows modular design. This paper studies current sharing and circulating current among paralleled inverter modules and proposes a new parallel Operation method based on one-cycle control (OCC) with combined Vector Operation and bipolar Operation. With some minor additions to the original OCC circuit and a simple add-on communication path among the individual modules, the current is properly shared among all the inverters and the circulating current is limited to an acceptable range, while OCC advantages such as constant switching frequency, no multipliers, and simple circuitry are preserved. Two OCC inverters of 1.5 kW each were built and tied together using the proposed parallel Operation. Experiments were conducted to demonstrate the simplicity and effectiveness of this method.
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parallel Operation of one cycle controlled three phase pfc rectifiers
IEEE Transactions on Industrial Electronics, 2007Co-Authors: Yang Chen, K M SmedleyAbstract:Parallel Operation of three-phase power-factor-corrected (PFC) rectifiers is a critical issue for high-power applications, since it extends the power range to a much higher level and allows modular design. The technical challenges are current sharing and circulating current control among the modules. This paper studies these phenomena within two paralleled rectifiers and proposes a new current-sharing method based on one-cycle control (OCC) with Vector Operation and bipolar Operation. With some minor additions to the original OCC circuit and a simple add-on communication path among the individual modules, the input current is shared and the circulating current is limited, while the OCC advantages, such as constant switching frequency, no multipliers, and simple circuitry, are preserved. Two OCC PFC rectifiers of 2.5 kW each were built and tied together using the proposed parallel Operation method. Experiments have demonstrated the simplicity and the effectiveness of this method.
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parallel Operation of one cycle controlled three phase pfc rectifiers
Applied Power Electronics Conference, 2005Co-Authors: Yang Chen, K M SmedleyAbstract:Parallel Operation of three-phase power factor corrected (PFC) rectifiers extends the power range to a much higher level and allows modular design. However, circulating current among the modules could be a potential problem. This paper studies the circulating current phenomenon within two paralleled rectifiers and proposes a new current sharing method based on one-cycle control with Vector Operation and bipolar Operation. With some minor addition to the original one-cycle control circuit and a simple add-on communication path among the individual modules, the circulating current is eliminated, while the OCC advantages, such as constant switching frequency, no multipliers, and simple circuitry, are preserved. Two one-cycle controlled rectifiers of 2.5 kW each were built and tied together using the proposed parallel Operation method. Experiments have shown the simplicity and the effectiveness of this method.
M V Romalis - One of the best experts on this subject based on the ideXlab platform.
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unshielded three axis Vector Operation of a spin exchange relaxation free atomic magnetometer
Applied Physics Letters, 2004Co-Authors: Scott J Seltzer, M V RomalisAbstract:We describe a Vector alkali–metal magnetometer that simultaneously and independently measures all three components of the magnetic field. Using a feedback system, the total field at the location of the magnetometer is kept near zero, suppressing the broadening due to spin-exchange collisions. The resonance linewidth and signal strength of the magnetometer compare favorably with two different scalar Operation modes in which spin-exchange relaxation is only partially suppressed. Magnetic field sensitivity on the order of 1pT∕Hz is demonstrated in a laboratory environment without magnetic shields.
Jaume Miret - One of the best experts on this subject based on the ideXlab platform.
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modeling and sliding mode control for three phase active power filters using the Vector Operation technique
IEEE Transactions on Industrial Electronics, 2018Co-Authors: Javier Morales, Luis Garcia De Vicuna, Ramon Guzman, Miguel Castilla, Jaume MiretAbstract:Traditionally, the Vector Operation technique (VOT) has been used to control three-phase converters using one cycle control. In this paper, a three-phase active power filter large-signal model with a VOT in a new coordinate system is presented. By using the VOT, only two phase-legs are switching at high frequency, thus reducing the switching losses. This paper not only covers the literature gap about the modeling of three-phase converters using the Vector Operation, but also presents a sliding mode control for this converter. The control scheme consists of a nonlinear matrix transformation in order to obtain the voltages and currents in a new two-dimensional frame, $\gamma \theta$ -frame, a sliding mode controller designed in these coordinates, and a modulator to obtain the control signals in a natural frame. The sliding mode control is designed with the help of the presented large-signal model assuring sinusoidal grid currents in phase with the grid voltages. This controller provides a fast transient response against sudden load changes with a good current tracking capability and a reduction of the switching losses. A stability analysis is performed in order to validate the control parameters. Experimental results are provided using a fully digital control system in order to validate the performances of the proposed controller.
Chongming Qiao - One of the best experts on this subject based on the ideXlab platform.
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one cycle control of three phase active power filter with Vector Operation
IEEE Transactions on Industrial Electronics, 2004Co-Authors: Chongming Qiao, K M SmedleyAbstract:Active power filters (APFs) provides an effective measure to eliminate the power line harmonic/reactive currents generated by nonlinear loads or by distributed energy sources that are connected to the grid. Active power filters are typically connected in parallel to the harmonic/reactive current sources and cancel the harmonic/reactive components in the line current so that the current flow into and from the grid is sinusoidal and in phase with the grid voltage. Since the APFs process only the harmonic/reactive power, their power-handling capability can be much higher than that of the cascade power-factor-correction methods. In this paper, the one-cycle control method is extended to control three-phase APFs. The proposed control approach employs one integrator with reset along with several logic and linear components to control a voltage-source converter to achieve three-phase unity power factor for the current to and from the power grid. No multipliers or sensors for the load current and the APF inductor current are required. Furthermore, there is no need to calculate the reference for controlling APF inductor current so that complicated digital computation is eliminated. The Operation switching frequency is constant that is desirable for industrial applications. The proposed control approach features great simplicity, excellent harmonic/reactive current cancellation, and solid stability. It is a cost-effective solution for power quality control for electronic equipment, buildings, industrial facilities, ships, airplanes, distributed power generation stations, etc. All findings are supported by experimental results.
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unified constant frequency integration control of three phase active power filter with Vector Operation
Power Electronics Specialists Conference, 2001Co-Authors: Chongming Qiao, Taotao Jin, K M SmedleyAbstract:In this paper, a unified constant-frequency integration control (UCI) scheme is proposed for a three-phase active power filter (APF). The proposed control method eliminates the need of sensing the three-phase load current, the nontrivial task of calculating the harmonics and reactive current components, as well as the use of any multipliers, as required by previously reported control methods. By applying one-cycle control and sensing the mains line current, unity power factor and low input current distortion can be realized by one integrator with reset along with a few linear and logic components such as flip-flops, comparators, and clock. All findings are supported by experimental results.
