Control of parallel single-phase inverters in a low-head pico-hydro off-grid network

Research output: Chapter in Book/Report/Conference proceedingConference Contribution (Conference Proceeding)

2 Citations (Scopus)

Abstract

In rural locations, where the national power grid is not available, pico hydropower (<;5kW) is typically used in stand-alone configurations, with one unit supplying a single house or a small community. This paper investigates the interconnection of several off-grid pico-hydro generation units with differing power ratings and unequal distances from the load. Each unit is identical, employing a single-phase power electronic converter interface, which comprises a rectifier, a DC-DC converter, and a single-phase inverter. There is no communication between the units, each unit using local measurements to control its output with the ability to form and support an off-grid network. The inverter regulates the output voltage and frequency using droop control. The output impedance is fixed using a virtual resistance, decoupling the droop equations. The voltage control loop has addition harmonic loops to improve voltage quality. The droop coefficients and virtual resistance are adjusted according to the power available at the turbine to ensure that the power sharing is proportional to the available turbine power. Experimental results show that the harmonic voltage control loops improve the voltage quality significantly, with the total harmonic distortion reducing from 9.53% to 1.93% when a non-linear load is connected to a single inverter. The transient response of two parallel inverters to the switching in of a non-linear load, and the response of the power sharing ratio to the hydraulic head at one turbine unit being reduced are demonstrated and shown to be stable.
Original languageEnglish
Title of host publicationIECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society
Subtitle of host publicationProceedings of a meeting held 10-13 November 2013, Vienna, Austria
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Pages1571-1576
Number of pages6
ISBN (Electronic)9781479902248
ISBN (Print)9781479902255
DOIs
Publication statusPublished - Mar 2014
Event39th Annual Conference of the IEEE Industrial Electronics Society, IECON 2013 - Vienna, Austria
Duration: 10 Nov 201314 Nov 2013

Publication series

NameProceedings of the IEEE Industrial Electronics Society (IECON)
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
ISSN (Print)1553-572X

Conference

Conference39th Annual Conference of the IEEE Industrial Electronics Society, IECON 2013
CountryAustria
CityVienna
Period10/11/1314/11/13

Keywords

  • rural electrification
  • Off-grid network
  • droop control
  • parallel inverter
  • pico-hydro

Fingerprint Dive into the research topics of 'Control of parallel single-phase inverters in a low-head pico-hydro off-grid network'. Together they form a unique fingerprint.

Cite this