【正文】 37 原文： MicroprocessorBased Protective Relays This article describes the benefits of microprocessor （μ P) relay performance and its capabilities beyond previous protective relaying technologies. This article also discusses a multiple qualitymeasurement approach to observing, measuring, and then calculating μ P relay reliability and unavailability. This is an important consideration for industrial and mercial facilities that are being required to repair or replace old electromechanical or solidstate (analog and digital) protective relaying equipment because of equipment malfunctions, misoperations, accidental tripping, or obsolescent parts. Although μ P relays have been mercially available for more than 20 years and researched for the past 40 years, industrial and mercial plant engineers tend to be more reluctant to embrace the μ P technology. Electric power utilities in North America have aggressively selected to replace older protection equipment by upgrading and replacing the equipment with new μ P relays whenever and wherever article is useful for consulting engineers, industrial and mercial electric power plant engineers, and original equipment manufacturer (OEM) engineers who are interested in doing reliability and unavailability predictions for industrial electric power distribution systems that employ μ P relays. Furthermore, this article assists thosemaking μ P relay costversusreliability decisions when performing facilities studies to evaluate and improve the system reliability or capacity of an existing plant. This article explores the benefits in performance (sensitivity and speed), reliability (security, selectivity, and dependability), availability, efficiency, economics, safety, patibility, and capabilities of μ P multifunction protective relaying technology over the previous existing technologies, namely electromechanical and solid suggested typical values, quality measurements, and analysis of protective relaying performance, reliability, and unavailability are intended to be a remendation of what could be used as a benchmark in our industry. In 1988, the article ‘‘Practical Benefits of MicroprocessorBased Relaying’’ [1], presented at the 15th Annual Western Protective Relay Conference(WPRC), described the equipment hardware and how typical earlymodel μ Pbased protective relays perform the signal processing from inputs, logic manipulations, and calculations. Later in 1991 and 1992, [2] and [3] provided good detailed explanations and examples of the increased operational flexibility and the additional features of μ P relays that better acmodate system disturbances, relay failures, protection philosophies, and changing power system conditions. With the significant cost and consequences of electric power systemfailures being increased, 38 often a single forced outage can drastically exceed the replacement project cost of the failed electrical distribution equipment. Furthermore, managers and operators of industrial plants that have NASA’s ‘‘failure is not an option’’ mindset regarding forced process outages will be required to look at the inherent reliability of a plant’s electric power system, including the protective relaying devices and ponents of the electrical distribution equipment, to attempt to approach zero defects for uncleared electric system faults. Definitions With reference to [4], the following definitions of the terms used in this article are provided: Quality: The totality of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs. Reliability (of a relay or relay system): A measure of the degree of certainty that the relay, or relay system, will perform correctly. Note: Reliabilitydenotes certainty of correct operation (dependabil ity) together with assurance against incorrect operation (security) from all extraneous causes. Availability: As applied either to the performance of individual ponents or to that of a system, it is the longterm average fraction of time that a ponent or system is in service and satisfacto rily performing its intended function. An alternative and equivalent definition for availability is the steadystate probability that a ponent or system is in service. Unavailability: The longterm average fraction of time that a ponent or system is out of service due to failures or scheduled outages. An alternative definition is the steadystate probability that a ponent or system is out of service due to failures or scheduled outages. Mathematically, unavailability 188。促成因素，早期的靜態(tài)繼電器差的質(zhì)量，在 1老齡產(chǎn)業(yè)的勞動(dòng)力不愿擁抱的技術(shù)變化，在關(guān)卡 1的新技術(shù)相關(guān)的學(xué)習(xí)曲線，是太難配置和設(shè)置微處理器繼電器的看法。相比之下，電力工業(yè)和商業(yè)用戶通常不升級(jí)他們現(xiàn)有的繼電保護(hù)設(shè)備，但往往選擇保留現(xiàn)有的防護(hù)裝備，直到它最終失敗。這個(gè)簡單的比較發(fā)現(xiàn)，其他幾個(gè)項(xiàng)目的重要意義，應(yīng)被視為不僅僅是繼電保護(hù)設(shè)備的購買價(jià)格。 表 3總結(jié)了我們超過十年期間為一個(gè)單一的微處理器的繼電器和一個(gè)單一功能的電子病歷的總擁有成本的比較。擁有成本對(duì)于這篇文章的目的，我們用我們已知的微處理器的繼電器成本持續(xù)時(shí)間，但有一些電子病歷估計(jì)成本和工期。 使用較早的信息，并了解未清除故障的直接和間接成本，能夠確定這一級(jí)別不可用的成本。如果植物是呈放射狀 配置的系統(tǒng)，并使用只有單個(gè)主保護(hù)整個(gè)微處理器的繼電器平均， UNAVAIL的能力保護(hù)繼電器（ 8）為 106，然后故障保護(hù)會(huì) NUF = 2 500 106 其中 NUF是每年未清除故障。 故障頻率，假設(shè)故障是隨機(jī)的，獨(dú)立的繼電保護(hù)故障，我們可以說不可用，繼電器是繼電保護(hù)電力系統(tǒng)發(fā)生故障時(shí)，不可用的可能性。然而，心肌梗死，只需要一個(gè)被迫中斷的后果，如果不能在未來的規(guī)劃和計(jì)劃的過程中停電繼電器維護(hù)。 從它的故障率，以確定一個(gè)單位的不可用，我們需要知道所花費(fèi)的時(shí)間來檢測和修理 35 單位的故障或缺陷。 一個(gè)微處理器繼電器的故障率預(yù)測設(shè)備的維修費(fèi)用是非常有用的，但沒有說明是否微處理器的繼電器將履行其保護(hù)功能，當(dāng)需要在電力系統(tǒng)故障條件。工業(yè)和商業(yè)電力系統(tǒng)部分是單應(yīng)變可靠的，但這些電力系統(tǒng)的大部份是徑向的，沒有平行饋線。 不可用 通常情況下，除非更高的可靠性是必要的，電力公司的輸電和配電（ T＆ D）系統(tǒng)規(guī)劃，設(shè)計(jì)，并采用單（ N 1）應(yīng)變分析，這可能包括或不包括斷路器故障和總線故障分析。這些觀測值的基礎(chǔ)上根據(jù)我們的無過錯(cuò)十年，全球免費(fèi)維修服務(wù)保修由客戶向我們返回的繼電器和維修，拆卸和維修經(jīng)驗(yàn)，因此準(zhǔn)確的測量。 對(duì)于一個(gè) 80 年代的 MI，每 80 繼電器（每年）之一，可以預(yù)期有硬件缺陷，生產(chǎn)過程中的缺陷，固件缺陷，發(fā)現(xiàn)沒有問題 回報(bào)，或服務(wù)公告相關(guān)的維修建。一旦關(guān)注的是觀察到的是一個(gè)明顯的趨勢和問題，我們發(fā)出服務(wù)公告，主動(dòng)告知客戶已知的故障模式（ S）。 在 2022年，我們還推出了心肌梗死的測 量，測量 MTBR加上所有相關(guān)服務(wù)的公告升級(jí)。這些單位的失敗是在智商測量，但不包括在 MTBF 和 MTBR測量。 在 2022 年，我們推出的智商測量，措施觀察檢測我們的顧客在一個(gè)單位的收據(jù)或初步測試盒的錯(cuò)誤。 在生命早期的失敗是考慮這些故 障發(fā)生后兩天，但在第一年的一個(gè)單位的在職生活，而的有用的生