PS640UX series protection, measurement, & control device is integrated protection,measurement, and control device developed by Guodian Nanjing Automation Co. Ltd. It is applicable to substations and power plants of non-directly grounded system or small resistance grounded system at 110kV and lower voltage levels.PS640UX can be used to protect and control the power substation, and is also be widely used to Power Industry, Water conservancy industry, Traffic Industry, Oil industry,  commercial buildings,Chemical industry,Coal Industry, Metallurgical Industry and so on.