Application of Four-Switch-Based Three-Phase Grid-Connected Inverter to Connect Renewable Energy Source to a Generalized Unbalanced Microgrid System

Abstract

In this paper, a four power semiconductor switch based three-phase inverter is proposed for renewable energy integration to a generalized micro-grid system. The proposed topology b-4 of three-phase inverter is investigated to make the commercial micro-grid system to be cost effective and hardware optimized. A simple Sine PWM (SPWM) based control strategy is proposed for the b-4 inverter topology instead of the traditional complex four-switch based Space Vector techniques. The overall control structure is implemented using the Lyapunov function based non-linear controller to track the inverter current directly in the a-b-c frame so that a specific amount of active and reactive grid power flow can be controlled in a de-coupled manner along with low THD of grid currents in the presence of non-linear load at the point of common coupling. A novel technique of using the Spatial Repetitive Controller (SRC) is also proposed to eliminate the effect of mid-point voltage fluctuation of the DC link even in the case of asymmetrically split DC link capacitors without any extra voltage or current sensors unlike conventional methods. Detailed experimental results are provided to show the efficacy of the proposed hardware system for grid connected applications in the micro-grid.Index Terms-four-switch based three-phase inverter (b4-topology), Generalized three-phase micro-grid bus, Sine PWM based control, Non-linear load

Sensorless Control of PMSM by a Four-Switch Inverter with Compensation of Voltage Distortion and Adjustment of Position Estimation Gain

“…The d-q axis voltage equation of a salient-pole PMSM is given as (8) and the back-EMF can be expressed as (9). Derivative term of γ-δ axis currents can be expressed as (11).…”

“…proposed an independent control scheme of two PMSMs by using two B4 inverters [7]. In [8], B4 inverters are used for integrating renewable energy sources into microgrid system. Recently, B4 topology is being studied as a provision for the emergency operation against inverter failure as well [9].…”

Review of Multifunctional Inverter Topologies and Control Schemes Used in Distributed Generation Systems

“…Fig. 5 shows the circuit topology of a three-phase, two-leg, three-wire inverter that generates active power in the utility system to simultaneously achieve harmonic and reactive power compensation [128], [129]. Except for three-phase loads, some industrial facilities often consist of combined loads, such as a variety of single-phase and three-phase loads supplied by a 3P4W source.…”

Improved Performance of Four Switch Three Phase with SEPIC-Based Inverter

“…The SEPIC converter is a fourth-order nonlinear system that is widely used in step-down or step-up DC-DC switching circuits, photovoltaic maximum power point tracking [6], and power factor correction circuits [7,8,9] due to its encouraging features as the non-inverting output voltage buck-boost capability and lower input current ripple content. Based on the above-mentioned advantages, SEPIC converter has been recently researched by scholars in various topologies in many diversified studies [10,11].…”