国臣学院-pg电子游戏

wenbo chen mingtian fan zhonghua mei zhang bao
gc company – china cepri – china gc company – china gc company – china

abstract
the inverter is widely used for its obvious advantages in soft start, variable frequency speed control, optimaldesign, economic operation and so on, however its continuous operation is seriously affected by voltage sags. during voltage sag, the inverter will be tripped because of low voltage protection, which would cause the important motor driven by inverter to stop working. this will result in non planned outage in the continuous production enterprises, leading to huge economic losses
and even personal safety accidents and environment problems. according to the characteristics of inverter’s ac-dc-ac structure and combining power electronics technology two kinds of voltage sag protection (vsp) systems are researched and developed based on dc support technology which take network residual voltage and batteries as energy source, respectively. and through boost dc/dc converter, the vsp system outputs a constant dc voltage, supporting inverter’s dc bus. the
system with batteries also can be used to protect inverter from short interruption. in accordance with the duration of voltage sag and load requirements, the design of protection system and the configuration of batteries is introduced. experimental data and field applications show that the two kinds of vsp system can ensure the normal operation of inverter during voltage sag which greatly improves the reliability on demand side and saves a lot of economic loss for users.
key words: voltage sags, protection, inverter, dc support technology