Large Chemical Companies' Measures For Anti-voltage Sag

Power grid volatility is inevitable due to its wide coverage, complex properties of users and influence of environment, equipment and human activities. Modern coal chemical industry operates on specific conditions characterized by high temperature and pressure, strong corrosion, inflammability, explosibility, and poisoning, which raises demands for electric energy of high quality and reliable power supply system. When the voltage of grid reduces to a certain level, the output of equipment units derates. This results in medium interruption, which poses a serious threat to the safety of equipment or even human beings. Thus, equipment units' functioning properly or safe parking is significant under voltage sags or interruptions. Based on these facts, higher requirement to the reliability of the chemical power supply system is raised. In this paper, we discuss several measures for anti-voltage sag including DC-BANK support system, Dynamic Voltage Restorer and high-speed bus transfer device.