Study On Recovery Of Voltage Sags Based On A New Generation Of DVR And UPQC

With the rapid development of electricity technology and the great increase in installed capacity, supply and demand contradiction was no longer the principal contradiction of the power system. As the more precise equipment is required, the high- tech industry relies on high-quality electricity in increasing degree. Since nonlinear loads, impact loads, asymmetrical loads in power grid have been increasing gradually in recent years, as well as more requirements of the electricity quality is proposed by precise and sensitive production equipment, the electricity quality has gradually became the major problem. Sensitive users such as precise apparatuses industry, lar ge financial data center and biological pharmacy industry propose for higher electricity quality, since even tens of milliseconds voltage sag will cause equipment damage and production line stop, which cause great financial losses. For better guaranteeing social and economic development, power supply enterprises face a great chal enge result from the electricity quality problem.The textual research contents have primarily below several parts: study about voltage sag control reconnaissance. To solve voltage sag problem, a project to control the voltage sag was drafted. The overall control project is that a DVR will be installed in a 10 k V line with sensitive load and a UPQC will be installed in 380 V side. The concreteness as follows:First, a survey about voltage sag was carried out to ascertain the key control area. When the key control area was ascertained, the key control user would be ascertained according to user’s level of sensitivity,degree of contamination and times of complaint.After ascertained the key control area and key control user, research about control scheme would be carried on. The overall control project is that a DVR will be installed in a 10 k V line with sensitive load and a UPQC will be installed in 380 V side to prevent voltage swell. DVR is used to compensate voltage sag, and a UPQC will be installed in low tension side to prevent voltage swell. So research about self-powered 10 k V DVR and UPQC is carried on.At the last, Simulation analysis of the effect of voltage sag compensation. And the result indicates that the project is feasible.