The effects of plug-in electric vehicles on a small distribution grid

The demand for plug-in hybrid electric vehicles (PHEVs) is increasing rapidly which will pose complications in terms of supplying the power required to charge these electric vehicles´ batteries. Idaho Power has contracted the EVI team to determine what power quality issues will be caused by the additional load on the electric grid incurred through charging PHEV batteries. The research performed by the EVI team will allow Idaho Power to ensure that they will be able to provide sufficient and reliable power as the load added by the charging of PHEV batteries increases. By the year 2040, the addition of PHEV battery charging will increase existing load by 18%. This increase in loading will cause the voltage in some ancillary areas to drop below 96% of nominal voltage. The additional load will require transformers, capacitors and other power distribution devices to be upgraded. A shift in charging times away from peak hours to later in the evening will result in a reduction in peak loading. The strain placed on the power grid by the charging of PHEV batteries can be managed by implementing a time of day incentive plan in conjunction with the systematic replacement of underrated devices.