Three-phase

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

A Three-Level Common-Mode Voltage Eliminated Inverter With Single DC Supply Using Flying Capacitor Inverter and Cascaded H-Bridge

Abstract: A three-level common-mode voltage eliminated inverter with single dc supply using flying capacitor inverter and cascaded H-bridge has been proposed in this paper. The three phase space vector polygon formed by this configuration and the polygon formed by the common-mode eliminated states have been discussed. The entire system is simulated in Simulink and the results are experimentally verified. This system has an advantage that if one of devices in the H-bridge fails, the system can still be operated as a normal three-level inverter at full power. This inverter has many other advantages like use of single dc supply, making it possible for a back-to-back grid-tied converter application, improved reliability, etc.

Cooperative Regulation of Imbalances in Three-Phase Four-Wire Microgrids Using Single-Phase Droop Control and Secondary Control Algorithms

Abstract: Collaborative control of power converters operating in microgrids with unbalanced single-phase loads is difficult to achieve, considering that the voltages and currents have positive-, negative-, and zero-sequence components. In this paper, a new control scheme for collaborative control of four-leg microgrids is proposed. The main advantage of the proposed methodology is simplicity, because the sharing of the powers produced by the positive-, negative-, and zero-sequence voltage and currents is simple to achieve using the easy to implement and well-known droop control algorithms, i.e., as those based on $P$ – $\omega$ and $Q$ – $v$ droop control. The proposed droop algorithms do not require high bandwidth communication channels and the application of virtual impedances, whose design usually demands extensive simulation work, is not required. Three secondary control systems are also analyzed, discussed, and implemented in this paper to regulate the frequency, voltage, and phase at the point of common coupling (PCC), to achieve a balanced 50-Hz three-phase voltage supply in the PCC during steady-state operation. For these secondary control systems, single-phase phase-locked loop based on quadrature signal generators are implemented. Small signal modeling and design are discussed in this paper. A microgrid prototype of $\approx$ 5 kW, implemented using two power converters of 3 kW (each), is used to experimentally validate the proposed algorithms.

Three-phase active harmonic rectifier (AHR) to improve utility input current THD in telecommunication power distribution system

Abstract: Modern telecommunication power supply systems have several parallel-connected switch-mode rectifiers to provide -48 V DC. A typical switch-mode rectifier configuration includes a three-phase diode rectifier followed by a DC-DC converter. Such a system draws significant harmonic currents for the utility, resulting in poor input power factor and high total harmonic distortion. In this paper, a three-phase active harmonic rectifier (AHR) scheme is proposed. In the AHR scheme, a diode rectifier module is replaced by a six-insulated-gate-bipolar-transistor pulsewidth-modulation rectifier to supply load harmonics as well as its own active power. Each DC-DC converter module is connected to a shared 48-V DC link. The AHR module together with parallel-connected switch-mode rectifiers is controlled to achieve clean input power characteristics. The VA ratings of the AHR scheme is compared with an active power filter approach. The control design is based on the synchronous reference frame approach. Analysis, simulation, and experimental results show that the AHR offers several advantages such as lower VA rating, better current control response, efficient use of the AHR DC link, small size, and stable DC-link voltage control.

A Versatile Voltage Controlled Three Phase Oscillator

Abstract: A new method for constructing three phase analog oscillators is suggested and dealt with. The new method is essentially an extension into the three phase domain of methods known previously for the generation of sinewaves in two phases. An electronic realization of the method has resulted in a successful instrument whose performance is tested in the present paper.

Single phase to three phase converter

Abstract: A converter for providing three phase power to a three phase load from a single phase supply includes an inverter connected to single phase input power lines and a bi-directional switch connected in series with one of the input power lines. The converter has three output lines, one connected to the inverter output, another connected to an input power line between the bi-directional switch and the inverter, and the third connected directly to the other input power line. The inverter switching devices are controlled to provide a signal on the output of the inverter to provide balanced three phase power on the converter output lines. This is preferably accomplished by pulse width modulation of an inverter output voltage reference signal derived by phase shifting the single phase input voltage signal by 60°. The inverter is preferably also controlled to phase shift the inverter output signal when necessary to ensure that the net power flow into the inverter is zero under light load conditions. During load start-up, the bi-directional switch is phase controlled to adjust the amplitude of the converter output current to thereby adjust the load current to limit inrush current levels and provide a soft starter by ramping up the current in the load.