Assessment of voltage unbalance

This paper endeavors to present a comprehensive summary of the causes and e ffects of voltage unbalance and to discuss related standards, definitions a nd mitigation techniques. Several causes of voltage unbalance on the power system and in industrial facilities are presented as well as the resulting adverse effects on the system and on equipment such as induction motors and power electronic converters and drives. Standards addressing voltage unbal ance are discussed and clarified, and several mitigation techniques are sug gested to correct voltage unbalance problems. This paper makes apparent the importance of identifying potential unbalance problems for the benefit of both the utility and customer.