Power Quality Consideration for Off-Grid Renewable Energy Systems

Abstract

Necessity of electricity access in remote area is the main reason for expanding decentralized energy system such as stand-alone power systems. The best electrical power supply must provide a constant magnitude and frequency voltage. Therefore, good power quality is an important factor for the reliable operation of electrical loads in a power system. However, the current drawn by most of electronic devices and non-linear loads are non-sinusoidal, which can result in a poor power quality, especially in off-grid power systems. Poor power quality is characterized by electrical disturbances such as transients, sags, swells, harmonics and even interruptions in the power supply. Off-grid power systems worldwide often struggle with system failures and equipment damage due to poor power quality. In this paper, MAT-LAB/Simulink is used to model and analyses power quality in an off-grid renewable energy system. The results show high voltage transient when the inductive loads were switched OFF. The voltage and current harmonics are also determined and compared for various types of loads.

Investigation of Harmonic Effects in Locational Marginal Pricing and Developing a Framework for LMP Calculation

“…The skin effect dominates the resistance by increasing frequency. Also, the skin effect on the resistance of a circular conductor is expressed as follows [34]: (19) where m is as below:…”

“…The utility companies usually install mitigation equipment to maintain the quality of power supply. The cost of this installed equipment must be recovered from the consumers who have caused the power quality problem, i.e., harmonic distortion [19].…”

A common ground switched capacitor‐based single‐phase five‐level transformerless inverter for photovoltaic application

“…If the LC exceeds 30 mA, the inverter must be unplugged within 0.3 s, according to the German standard VDE 0126-1-1. 2 According to IEEE 1547 and IEC 61727 standards, 3,4 the DC injection from the inverter must be maintained at less than 0.5% of the rated current in addition to limiting LC. Therefore, all these issues should be minimized while designing a PV grid-connected system.…”

Harmonic Distortion Contribution for the Transmission Loss Allocation in Deregulated Energy Market: A New Scheme for Industry Consumer

“…Meanwhile, by using electronic devices and non-linear load non-sinusoidal, which can result in poor power quality. It can cause of electrical disturbances like transients, sags, swells, harmonics, and even disruption in power supply [4]. And also, can be to increase of losses in line due harmonic component for line flow.…”

“…Once this equipment is installed, its cost must be recovered from the consumers who have caused the power quality (PQ) problem, i.e. harmonic distortion [4]. The consumer will pay according to the amount of stress (usage) that their equipment causes onto the mitigation equipment [5].…”