Three-phase

About: Three-phase is a research topic. Over the lifetime, 16801 publications have been published within this topic receiving 159477 citations.

Three-Phase VSI Optimal Switching Loss Reduction Using Variable Switching Frequency

Abstract: Loss reduction in converters is one of main targets in power electronics to obtain higher efficiency and lower thermal stress, which can enhance the lifetime of devices. This paper presents a variable switching frequency technique for switching loss reduction in a three-phase voltage source inverter, obtaining similar output current quality as that of a space vector pulse width modulation (SVPWM) algorithm. This type of optimization has not been applied for a three-phase system before. Simulation and experimental results are also shown. The output current ripple rms value of three-phase SVPWM is used as the optimization constraint. Results of the optimization of the switching losses with quality constraints in the switching frequency as the variable are presented for different load angles and compared with classical SVPWM. Experimental results show that this technique can save up to nearly $19\%$ in switching losses with similar total harmonic distortion of the output current, concluding that converter losses are reduced without reducing output current quality.

Research on cascaded three-phase-bridge multilevel converter based on CPS-PWM

Abstract: Cascaded multilevel converters are emerging as a new breed of power converter options for high-voltage and high-power applications. A cascaded three-phase-bridge (C3PB) multilevel topology is proposed in this study. The new multilevel converter topology is derived from an optimum combination of three-phase voltage source converter modules and it needs fewer switches and dc capacitors than Δ-connected cascaded H-bridge converter under the similar operation condition. The characteristics of the C3PB converter are presented through analysing its current relationship, voltage relationship and power allocation in detail; the analysis results show that all the converter modules equally share the output power. Based on carrier phase-shifted pulse-width modulation (CPS-PWM) technique, simulation results of two-level and three-level inverter are given to verify the theoretical analysis; meanwhile, CPS-PWM and power decoupling control method are employed to validate the three-level C3PB rectifier. Finally, based on Digital Signal Processor (DSP) + Field Programmable Gate Array (FPGA) control board, a lab prototype is built to verify the validity and feasibility of the proposed C3PB converter along with the proposed control method.

A novel single- to three-phase static converter

Abstract: A comprehensive analysis of a phase converter structure capable of providing three-phase AC power from existing single-phase AC mains by using the principle of cycloconversion is presented. The proposed converter provides balanced three-phase output power and generates a low-distortion input current. However, output voltages contain low-order harmonics which can be easily filtered. The simple control logic circuit and the six-switch converter configuration required make the proposed phase conversion scheme attractive economically as well as practically. Experimental results obtained on a laboratory prototype have been used to prove the validity of respective predicted results. >

Three-level hysteresis current control strategy for three-phase four-switch shunt active filters

Abstract: In this study, a three-level hysteresis current-control (HCC) strategy is proposed for three-phase four-switch shunt active power filters. The four-switch topology which utilises four switching devices together with two series connected capacitors is able to reduce the cost, switching losses and improve the reliability of system. In this topology, when the current control of phases A and B is achieved successfully, the current control of phase C which is connected to the midpoint of the series connected capacitors is achieved automatically. The current control is achieved by using a three-level HCC strategy. An important consequence of using this control strategy is that it enables access to the zero level of the input voltage of active filter so that a switching device is only switched when the current error is negative, while it remains off when the current error is positive. Furthermore, the imbalance in the capacitor voltages is eliminated by adding a feedback term (the difference in the capacitor voltages multiplied by a suitable gain) to the current control. The proposed control strategy offers a reduced switching frequency, losses and cost. The steady-state and dynamic performance of the proposed control strategy is verified through simulations and experimental studies.

High-Frequency Voltage Injection Sensorless Control Technique for IPMSMs Fed by a Three-Phase Four-Switch Inverter With a Single Current Sensor

Abstract: This paper proposes a sensorless control strategy using sine-wave high-frequency (HF) voltage injection for interior permanent magnet synchronous motors (IPMSMs) fed by a three-phase four-switch (TPFS) inverter, with a single current sensor. Three-phase currents are reconstructed by a single current sensor with modification of the inverter topology. The principle of the phase current reconstruction strategy in TPFS inverter is analyzed and the topology of the proposed drive system is illustrated. Then, the normal areas and the dead zones for current reconstruction are investigated in detail, and the vector synthesis method is also explained. Furthermore, the zero vector synthesis strategy and the pulse width modulation (PWM) generation method are also presented, where two current sampling points are applied in each PWM cycle for phase current reconstruction. Finally, an HF voltage injection based sensorless control strategy in the proposed drive system is realized by voltage projection on the proposed k – l axis coordinate system. The reconstructed phase currents track the actual ones accurately, and the estimation error of the rotor position by using the reconstructed phase currents is within ±0.1 rad. The effectiveness of the proposed scheme is verified by simulation and experimental results on a 5-kW IPMSM prototype.