Voltage unbalance reduction in low voltage feeders by dynamic switching of residential customers among three phases

Economic assessment of phase reconfiguration to mitigate the unbalance due to plug-in electric vehicles charging

“…While the autonomous rephasing of single phase loads was found to result in reduced absolute unbalance by 88% using fuzzy logic [19], and maximum voltage unbalance was reduced from 2.25% to 0.75% with a centralized control system [20]; such results do not assess the applicability of power electronic switching on North American split phase secondary systems. Furthermore, despite the work of [19,20] absolving the need for manual labour in phase reconfiguration and allow realtime control, these studies do not consider an economic assessment to justify the cost of the solution.…”

“…3a. Following the design of a static transfer switch in [20], each switch consists of a wireless ZigBee receiver, Triac, snubber circuit, and overvoltage protection; and is used to enable or disable power flow. Given the connections of Fig.…”

“…While the three-phase EV chargers in [18] provide significant unbalance reduction in the system, the burden of purchasing more expensive three-phase chargers is placed on the residential customer whom is not responsible for maintaining system operating conditions, and therefore is impractical. Similar solutions to mitigate unbalance have been proposed in [19,20], which suggest the usage of power electronic switching to offer a choice of three single phase connections from which to draw power for a single phase load when connected to a three phase secondary system. While the autonomous rephasing of single phase loads was found to result in reduced absolute unbalance by 88% using fuzzy logic [19], and maximum voltage unbalance was reduced from 2.25% to 0.75% with a centralized control system [20]; such results do not assess the applicability of power electronic switching on North American split phase secondary systems.…”

“…Studies [5,7,10] have assessed PBEV impact on secondary distribution systems and have reported up to 8% load unbalance [7] and 16% power unbalance [10] for 50% vehicle penetration. In response to the unbalance issues seen, studies [11][12][13][14][15][16][17][18][19][20] propose solutions to mitigate unbalance using methods such as: manual phase reconfiguration, transformer modification, and automated phase switching.…”

Voltage balancing in low‐voltage radial feeders using Scott transformers

“…In [7], energy storage was used for voltage imbalance mitigation and in [8] the solution was the use of a distribution network static compensator (STATCOM). The work in [9,10] presented a static switch-based voltage imbalance reduction method by transferring the residential load among the three phases. A method using a transformer with nine tap changers was proposed in [11] for power flow control in transmission systems, and this method was deemed suitable for voltage balancing in LV networks, but it required a complicated control algorithm.…”