Distributed monitoring and protection system for a distributed power network

• US 6,654,216 B2
• Filed: 10/01/2002
• Issued: 11/25/2003
• Est. Priority Date: 02/12/1999
• Status: Expired due to Fees

• Current Assignee: Bitronics, LLC
• Original Assignee: Bitronics, Inc.
• Inventors: Butt, James Allen, Horvath, Vincent Victor
• Primary Examiner(s): Jackson, Stephen W.
• Application Number:
  US10/262,126
• Publication Number:
  US 20030067725A1
• Time in Patent Office: 420 Days
• Field of Search: 361/42, 361/47, 361/62-75, 361/93.1, 361/93.9, 361/94-97
• US Class Current: 361/65
• CPC Class Codes: H02H 7/261 involving signal transmission between at least two stations transmission of signals in general H02H1/0061
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: H02J 13/00017 using optical fiber
• CPC Class Codes: H02J 13/00028 involving the use of Internet protocols
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H02J 13/0004 involved in a protection system
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/20 using protection elements, arrangements or systems
• CPC Class Codes: Y04S 10/30 State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge

Abstract

A distributed monitoring and protection system for a distributed power network. The system includes a plurality of high-speed measuring units (MUs), wherein each MU is coupled to a power line to measure values of electrical parameters of the power line. Electrical parameters, such as current, voltage, power and frequency are measured by the MUs. The MUs communicate with a control unit (CU) over a high-speed communications network. The CU includes a processor executing algorithms for evaluating the measured parameters to determine the status of the power network and the MUs. The processor also executes fault detection and isolation by comparing the measured values against predetermined threshold values. When a fault is detected by the CU, protective action, such as tripping of a circuit breaker, may be initiated by the CU directly or by transmitting the tripping command over the high speed data network to a local MU. The local MU may then trip the circuit breaker. The availability at the CU of concurrent measurements from the plurality of MUs enables improved coordination and sequencing of protective actions.

Claims

1. A distributed monitoring and protection system for a distributed power network comprising:

a plurality of lines for distributing electric power, the lines including protective devices, and at least two of the lines connected to different current nodes at different potentials,

an individual monitoring unit for measuring electrical parameters coupled to each of at least two of the lines, at least two of the monitoring units measuring electrical parameters from different current nodes at different potentials,

at least one control unit communicating remotely over a high-speed data network with each monitoring unit,

at least one monitoring unit coupled to a protective device, the at least one control unit including a processor for (a) comparing in the control unit the measured electrical parameters of one respective monitoring unit with the measured electrical parameters of at least one other respective monitoring unit, and (b) producing in the control unit an activating signal based on the comparison of the measured electrical parameters of the one respective monitoring unit with the measured electrical parameters of the at least one other respective monitoring unit, and

the control unit transmitting the activating signal to the at least one monitoring unit, and in response, the at least one monitoring unit producing a tripping signal for tripping the protective device.

2. In a distributed power network having a plurality of power lines wherein at least two of the power lines are connected to different current nodes at different potentials and each power line includes a protective device, a method for activating a protective device comprising the steps of:

(a) measuring electrical parameters by respective monitoring units in at least two of the power lines connected to different current nodes at different potentials;

(b) transmitting at high speed the measured electrical parameters from the respective monitoring units to a remotely located control unit;

(c) comparing in the control unit the measured electrical parameters of one respective monitoring unit with the measured electrical parameters of at least one other respective monitoring unit;

(d) producing in the control unit an activating signal based on the comparison of the measured electrical parameters of the one respective monitoring unit with the measured electrical parameters of the at least one other respective monitoring unit; and

(e) transmitting the activating signal from the control unit to a monitoring unit for producing a tripping signal based on the activating signal, and

(f) tripping a protective device by the monitoring unit in response to the tripping signal.