A novel approach forgrid‐connectedinverter operation based on selective harmonic elimination

Abstract

In this article, the feasibility of selective harmonic elimination for grid-connected operation of low voltage DC sources is presented. An appropriate fixed switching pattern is able to achieve good quality current while minimizing switching operations, thereby improving the inverter efficiency. In an attempt to establish the potential advantages over conventional PWM techniques, this article demonstrates the application of SHE in grid connect applications, especially in high power levels while maintaining the ability to provide an independent control of active and reactive powers. The problem formulation is based on using a fixed switching pattern that provides a certain fundamental voltage and eliminates 5 th , 7 th , 11 th , 13 th , 17 th , 19 th , 23 rd , 25 th , 29 th , and 31 st harmonic order. A power structure consisting of two-stage power conversion is proposed to make this possible, enabling amplitude and phase control of the generated AC voltage from the inverter. An LCL filter has been used for grid interface. The switching pattern and the development of control structure are presented. Simulation studies are discussed and experimental results shown validate the proposed scheme.

Performance evaluation of a grid‐connected three‐phase six‐switch boost‐type current source PV inverter under different switching strategies

“…Moreover, they utilize bulky and non‐reliable electrolytic DC‐link capacitors as storage elements. The latter decrease the reliability and the lifespan of the power conversion system as provided by C. Poongothai et al 2 …”

“…Moreover, they utilize bulky and non-reliable electrolytic DC-link capacitors as storage elements. The latter decrease the reliability and the lifespan of the power conversion system as provided by C. Poongothai et al 2 On the other hand, current source inverters (CSIs) are, inherently, boost-type topologies since they allow the injection of high-quality sinusoidal currents into the grid with a DC-link voltage lower than the grid voltage. Moreover, the DC-link electrolytic capacitors are substituted by small DC-link inductors.…”

Selective Harmonic Elimination Notch Angle Calculation Using THD and ZHF Benchmarks for Cascaded Multilevel Inverters

“…This research paper compares three, five and thirteen level MLIs using the Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) switching technique. SHE-PWM is a modulation technique that switches at low frequency and provides tailored control of low-order harmonics and reduces switching losses [24], [25], [26], [27], [28]. In each case, MLIs will use SHE-PWM control scheme and the output voltage waveform of each has six notch angles (using quarter waveform symmetry).…”