Ground distance relay for ac power transmission line protection

Patent · Tue Aug 11 04:00:00 EDT 1987

OSTI ID:6160846

Alexander, G F; Wilkinson, S B

This patent describes a ground distance protective relay for protecting a three-phase alternating current power transmission line by generating a tripping signal in response to a fault on any phase of the line in a predetermined zone of protection. The relay is of the phase comparator type and includes: phase coincidence detection means responsive to input signals supplied thereto for developing an output signal when there is phase coincidence between the input signals, a first of the input signals being an operating signal and a second of the input signals being a polarizing signal, and timer circuit means for developing an output responsive to the output signal from the phase coincidence detecting means continuing for a predetermined duration. The improvement described consists of: (a) means for deriving the first input signal from component signals that are summed together; (b) means for deriving the second input signal from component signals that are summed together; and (c) clipping means for limiting to a predetermined maximum value at least one of the component signals.

• Assignee: General Electric Co., King of Prussia, PA
• Patent Number(s): US 4686601
• OSTI ID: 6160846
• Country of Publication: United States
• Language: English

Related Subjects

200301* -- Power Transmission & Distribution-- AC Systems
EHV & UHV-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
ALTERNATING CURRENT
COMPARATOR CIRCUITS
CURRENTS
ELECTRIC CURRENTS
ELECTRIC GROUNDS
ELECTRICAL EQUIPMENT
ELECTRICAL FAULTS
ELECTRONIC CIRCUITS
EQUIPMENT
POLARIZATION
POWER TRANSMISSION LINES
RELAYS
SIGNALS
TIMING CIRCUITS