Protective Relaying. ▪ Primary Line Protection: Directional Comparison Unblocking Pilot Relaying over Power Line Carrier shall be provided via the existing numerical distance relay. This relaying system shall be set selective within the prescribed zones of protection based on system protection analysis. The relay will directly trip and block the closure of the breaker(s). The relay shall be of utility grade and meet Transmission Owner’s standards. Identical primary line protection will be installed for the second line connection. ▪ Secondary Line Protection: Line Current Differential Relaying over Digital Microwave channels will be provided via a microprocessor based current differential relay. This relay will be set to provide backup distance protection if the communications channels are lost and be selective within the prescribed zones of protection based on system protection analysis. The relay will directly trip and block the closure of the breaker(s). Identical secondary line protection will installed for the second line connection. ▪ Breaker Failure: Two independent primary and secondary breaker failure relaying systems provide redundant breaker failure protection. After a circuit breaker trip is initiated, the breaker failure relay will begin a countdown timer. If the circuit breaker fails to open within a specified period, then the breaker failure relay and its associated lockout relay will trip and block closure of an adjacent circuit breaker(s) and send direct transfer trip to the remote terminal station to isolate the stuck breaker. The relay shall be of utility grade and meet Transmission Owner’s standards. ▪ Transfer Trip: The breaker failure conditions at Transmission Owner terminals will be remotely tripped at the Xxxx Substation upon receiving direct transfer trip (DTT) signals from Xxxxxx and/or Plattsburgh substations. The breaker failure conditions at the Xxxx Substation will be remotely tripped at the Transmission Owner’s Terminal upon receiving DTT signals from the Xxxx Substation. The Phase II protection will be coordinated with the Xxxxxx Substation and the Plattsburgh Substation remote line relays.
Protective Relaying. Main Step-
Protective Relaying on the Inter-tie Circuit Breaker
Protective Relaying. Primary Line Protection: Directional Comparison Unblocking Pilot Relaying over Power Line Carrier shall be provided via the existing numerical distance relay. This relaying system shall be set selective within the prescribed zones of protection based on system protection analysis. The relay will directly trip and block the closure of the breaker(s). The relay shall be of utility grade and meet Transmission Owner’s standards. Identical primary line protection will be installed for the second line connection.
Protective Relaying. The selection and application of protective relays are discussed in the following paragraphs. These relays protect equipment in the Auxiliary Power Supply System, Generator Terminal System, Primary Power Supply System, Turbine-Generator System, and the electrical loads powered from these systems. -------------------------------------------------------------------------------- Proprietary Information Page 18 AES IRONWOOD CONTRACT FINAL ISSUE - OCTOBER 30, 19988 -------------------------------------------------------------------------------- 2x1 501G REFERENCE PLANT APPLICATION HANDBOOK -------------------------------------------------------------------------------- ELECTRICAL ENGINEERING DESIGN CRITERIA -------------------------------------------------------------------------------- The following general requirements apply to all protective relay applications:
Protective Relaying. Primary Line Protection: Distance relaying protection shall be provided via a numerical distance relay. This relaying system shall be set selective within the prescribed zones of protection based on the system protection analysis. The relay will directly trip and block the closure of the breaker(s). The relay shall be of utility grade and meet Transmission Owner’s standards. Secondary Line Protection: Distance relaying protection will be provided via a high speed microprocessor based distance relay. This relay shall be set to be selective within the prescribed zones of protection based on system protection analysis. The relay will directly trip and block the closure of the breaker(s). The relay shall be of utility grade and meet Transmission Owner’s standards. Breaker Failure: Two independent primary and secondary breaker failure relaying systems provide redundant breaker failure protection. After a circuit breaker trip is initiated the breaker failure relay will begin a countdown timer. If the circuit breaker fails to open within a specified period, then the breaker failure relay will trip its associated lockout relay to trip and block closure of the adjacent and series line circuit breakers. The breaker failure relaying at the Xxxx Substation does not send direct transfer trip to the remote terminal substation. The series line breaker is provided to isolate stuck breakers from the 230kV system. The relay shall be of utility grade and meet Transmission Owner’s standards. the DTT.
Protective Relaying. All SPPCo. required protective relay equipment will be located within the Steamboat substation meter house. The following relays are required by SPPCo. to isolate faults between the Steamboat substation and Far West's facilities as well as to prevent Far West from islanding with a portion of SPPCo.'s system under abnormal system conditions:
a. Over/under frequency b. Over/under voltage c. Synchronism check d. Overcurrent (phase and ground, possible directional) This list is not exhaustive and may be expanded and refined. SPPCo's relaying and protection design personnel will make a final determination concerning the required hardware and equipment settings.
Protective Relaying. SCHEMATICS Responsibility: POWER Deliverable(s):
Protective Relaying. The protective relaying system shall be provided to protect all electrical systems and equipment supplied from them. The Contractor shall submit a complete short circuit and relay co-ordination study in conjunction with the detailed relay and control drawings and protective device settings for review by the Owner before implementation. The following general requirements apply to all protective relaying applications: o The protective relay system shall be designed to remove or alarm abnormal operating occurrences occurring on equipment designed for electrical power generation, voltage transformation, energy conversion, and transmission and distribution of electrical power. o The protection system shall provide discrimination with other protection systems. o To limit damage to faulted equipment. o Minimize possibility of fire or explosion. o Minimize hazard to personnel. o The protection equipment shall consist of proven, self-diagnosing, digital type relays with complementary functions and sufficient redundancy to ensure that faults are detected and cleared without disruption to unaffected supplies. The scheme shall incorporate overlapping zones of protection with principal plant items provided with back-up protection in addition to the primary protection. o Relays may be offered as individual or combination devices incorporating more than one function. Protection devices providing mutual backup shall be placed in different groups. o Relays shall have sufficient setting ranges to cater for all conceivable instrument transformer characteristics, discrimination requirements, and sensitivities to fault conditions. o Each relay shall be clearly labelled with relay type and descriptive function. Relays shall be installed and wired in switchgear in accordance with Applicable Codes and Standards and industry practice. o Relay and metering potential circuits shall be segregated and individually protected by fuses or MCCBs. o Primary and secondary trip circuits (DC) shall be segregated. Primary trip circuits, high priority trip circuits and relay power supply circuits shall be segregated. Circuit protection devices shall not be included in relay trip circuits. o Protective relays shall be equipped with high speed recording facilities for voltage and current. Fault information, disturbance and event records shall be available via simple system integration protocols to provide fast fault diagnosis via a PC or the DCS.
Protective Relaying. The criteria for selection and application of protective relays are discussed in the following paragraphs. These relays protect the turbine generators, isophase bus, nonsegregated phase bus duct, generator circuit breakers (when used), unit auxiliary transformer circuit breaker, (when used) generator step-up transformer, unit auxiliary transformer, metal-enclosed bus duct, 4.16 kV metal-clad switchgear, and plant electrical loads. Protective relaying shall be provided as required by the following paragraphs. The following general requirements apply to all protective relay applications. The protective relaying scheme shall be designed to remove or alarm any of the following abnormal occurrences. Overcurrent Undervoltage or overvoltage Faults to ground Frequency variations Excessive pressure Open circuits and excessive unbalanced current Abnormal direction of power flow Out of synchronism Differential
