Impact of Long Distribution Cable to the Harmonic Distortion in Indonesia Remote Microgrids

Abstract

Providing electricity access to the farthest consumer in remote areas with limited infrastructure may require long low voltage cables. This could result in a high network impedance, hence high losses and high voltage drop. Moreover, the increasing adoption of power electronics in household appliances introduces nonlinear currents, which could also increase the losses. In terms of power quality, both high network impedance and nonlinear current will result in voltage distortion that could undermine the system's efficiency and reliability. Focusing on the effect of the network impedance at the frequency range of 1-150 kHz, this paper aims to investigate the electromagnetic compatibility issues that might be imposed by a long-span low voltage cable up to 2 km. The results show a nonlinear correlation between the voltage distortion, cable length and current amplitude. Furthermore, a noticeable increase in voltage distortion at the load side should be expected in a system with a higher source impedance as in remote microgrids. It can be reduced by implementing a capacitor bank at the source or a passive filter at the load side.

Trade-off of Losses, Voltage Drop, and Harmonics in Cable Selection of Remote Microgrids

“…Assuming a rural context, the value range of Rcable (1-5 Ω), Lcable (0.17-1.74 mH), and Ccable (0.03-2.7 nF) were defined, which is according to the NFA2X cable (the typical low voltage distribution cable i.e., aluminum conductor and XLPE insulation), 10-16 mm diameter. The simulated cable length is up to 2 km length, which can be expected in the actual remote area [4]. For the simulation, a source resistance was set as 0.2 Ω to mimic a weak supply, and a 50 Ω resistor that was connected through a full-bridge rectifier was used to represent an aggregate of nonlinear loads.…”

Risk of EMI due to Necessary Modification in a Remote Microgrid in Indonesia

“…For instance, incorrect reading in an energy meter due to EMI from a power drive system [4], over voltage in a generator due to resonance in the generator's electronic system with power line telecommunication signal [4], a failure due to inrush current or big nonlinear load switching in combination with the limited capacity of microgrids [5], and a high harmonic distortion due to nonlinear load could reduce the equipment operational life [6]. Although harmonics can be managed on the generation side, they could be significantly aggravated on the load side, especially when the use of long cables is required to electrify the furthest loads in remote areas [7]. These studies show that many potential early failures could undermine the system's operation, even though the system was expected to be designed properly.…”