Topic
Three-phase
About: Three-phase is a research topic. Over the lifetime, 16801 publications have been published within this topic receiving 159477 citations.
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16 Mar 2014
TL;DR: In this article, an impedance-based analysis method was proposed to analyze the grid-synchronization stability issue in paralleled three-phase converter systems, which showed that the multivariable generalized inverse Nyquist stability criterion (GINC) can be used to predict the system stability based on the grid and inverter impedances in the synchronous d-q frame.
Abstract: Grid synchronization instability issues and low frequency oscillations between synchronous generators exist in electrical power system. This kind of stability issue happens between paralleled power converters is also reported. Analysis based on small-signal model of inverters with phase-locked loops (PLL) has been proposed. Different from that approach, which needs detailed inverter and controller parameters, this paper proposes an impedance-based analysis method to analyze the grid-synchronization stability issue in paralleled three-phase converter systems. The proposed method shows that the multivariable generalized inverse Nyquist stability criterion (GINC) can be used to predict the system stability based on the grid and inverter impedances in the synchronous d-q frame. Furthermore, the instability is found to be caused by qq channel impedance interaction. Experimental results verify the analysis and the proposed method.
451 citations
TL;DR: A prototype system was constructed to verify the feasibility of the new three-phase bipolar inductive power transfer system that provides power across the entire width of a roadway surface for automatic guided vehicles and people mover systems.
Abstract: The development of a new three-phase bipolar inductive power transfer system that provides power across the entire width of a roadway surface for automatic guided vehicles and people mover systems is described. A prototype system was constructed to verify the feasibility of the design for a number of moving loads (toy cars). Here, 40 A/phase is supplied at 38.4 kHz to a 13-m-long test track. Flat pickups are used on the underside of each vehicle to couple power from the track to the vehicle. Finite element modeling software was used to design the geometrical position of the track cables and to predict the power output. This design resulted in a considerably wider power delivery zone than possible using a single-phase track layout and has been experimentally verified. Mutual coupling effects between the various track phases require additional compensation to be added to ensure balanced three-phase currents.
442 citations
TL;DR: In this paper, a proportional plus resonant (P+resonant) compensator is added into the outer voltage regulation loop to achieve zero steady error, to develop a high performance UPS control algorithm, which is applicable to both single-phase and three-phase systems.
Abstract: Most of the many reported control algorithms for uninterruptible power supplies (UPSs) use either filter inductor or filter capacitor currents as feedback variables to regulate the output voltage. This paper explores the fundamental performance issues associated with the use of these quantities as feedback variables, with a view to determining their contribution to the transient system response and output harmonic compensation in any particular situation. A proportional plus resonant (P+resonant) compensator is then added into the outer voltage regulation loop to achieve zero steady error, to develop a high performance UPS control algorithm, which is applicable to both single-phase and three-phase systems. Theory, simulation, and experimental results are presented in the paper.
422 citations
TL;DR: In this article, a zero-sequence model was developed to predict the dynamics of the zero-sequential current in parallel three-phase converters, where individual converters connect both AC and DC sides directly without additional passive components.
Abstract: One unique feature in parallel three-phase converters is a potential zero-sequence circulating current. To avoid the circulating current, most present technology uses an isolation approach, such as transformers or separate power supplies. This paper proposes a parallel system where individual converters connect both AC and DC sides directly without additional passive components to reduce size and cost of the overall parallel system. In this case, the control of the circulating current becomes an important objective in the converter design. This paper: (1) develops an averaged model of the parallel converters based on a phase-leg averaging technique; (2) a zero-sequence model is then developed to predict the dynamics of the zero-sequence current; (3) based on the zero-sequence model, this paper introduces a new control variable, which is associated with space-vector modulation; (4) a strong zero-sequence current control loop is designed to suppress the circulating current; and (5) simulation and experimental results validate the developed model and the proposed control scheme.
409 citations
TL;DR: In this article, a three-phase ac-ac sparse matrix converter with no energy storage elements and employing only 15 IGBTs, as opposed to 18 IGBT switches, was proposed.
Abstract: A novel three-phase ac-ac sparse matrix converter having no energy storage elements and employing only 15 IGBTs, as opposed to 18 IGBTs of a functionally equivalent conventional ac-ac matrix converter, is proposed. It is shown that the realization effort could be further reduced to only nine IGBTs in an ultra sparse matrix converter (USMC) in the case where only unidirectional power flow is required and the fundamental phase displacement at the input and at the output is limited to plusmnpi/6. The dependency of the voltage and current transfer ratios of the sparse matrix converters on the operating parameters is analyzed and a space vector modulation scheme is described in combination with a zero current commutation method. Finally, the sparse matrix concept is verified by simulation and experimentally using a 6.8-kW/400-V very sparse matrix converter, which is implemented with 12 IGBT switches, and USMC prototypes.
398 citations