PHOTOELECTRONIC PROTECTION RELAY SYSTEM OF OVERCURRENT

摘要

PURPOSE: A photoelectric protection relay system of over current is provided to solve a weak point failed to a functioning in a point needed to an exact measurement by generating a deterioration when an accident such as a short-circuit defect of an electric system. CONSTITUTION: A photoelectric sensor(600) sends an optical signal transmitted from a light emitting display by optically modulating according to a size of current with installing in a power line(800). The light emitting display of a transmitting and receiving unit of light(100) generates the optical signal using an LED(light emitting diode), and transmits to the photoelectric sensor(600) through an optical fiber(700). A light receiving element detects the optically modulated signal using a pin-photo diode. A processing unit of optical signal(200) converts the optical signal detected from the light receiving device to an electric signal, the analog signal is transferred to a main control unit through a memory device by converting to a digital signal in an A/D converting unit of a control unit of the protection relay, and the main control unit operates an assistant relay(400) by appropriately delaying a time fit for a function of the protection relay. The analog output signal of the signal processing unit(200) controls the assistant relay by converting to the digital signal with receiving from the control unit of protection relay. The photoelectric protection relay of over current is composed by programming the main control unit with a method for completing a difference between an input signal of an existing stop-typed over current protective relay and a signal processed in the processing unit of optical signal.