Name: power system protection zones
Uploaded: 2024-11-21T14:54:35.000Z
Duration: 1 min 16 s
Channel: JoVE

في أنظمة الطاقة ، ينقسم الإعداد بأكمله إلى مناطق واقية. إذا حدث خطأ داخل منطقة ما ، يتم عزله ، مما يحمي بقية النظام.
تشمل هذه المناطق المولدات والمحولات والحافلات وخطوط النقل والتوزيع والمحركات. فكر في هذه الغرف على أنها غرف مختلفة في المنزل ، كل منها محمي بقاطع الدائرة الخاص بها.
يتم تحديد كل غرفة أو منطقة بخط متقطع مغلق. داخل كل غرفة ، يمكن أن يكون هناك مكون واحد أو أكثر.
تشمل الخصائص الفريدة لهذه المناطق الواقية التداخل ووضع قاطع الدائرة. تشبه قواطع الدائرة الحراس الذين يقفون عند تقاطع هذه الغرف ، ويعزلون أي غرفة تواجه مشكلة.
لذلك ، في حالة حدوث عطل في المطبخ ، سيتم فتح جميع قواطع الدائرة المرتبطة بالمطبخ ، مما يؤدي إلى عزله ومنع الخطأ من التأثير على الغرف الأخرى.
تضمن المناطق المتداخلة عدم ترك أي منطقة دون حماية من خلال وجود بابين بين الغرف المجاورة ، لذلك إذا فشل أحدهما ، فلا يزال بإمكان الآخر الحماية.
يتم تحقيق التداخل باستخدام محولين ومرحلات للأجهزة لكل قاطع دائرة.

مناطق الحماية

Zones of Protection

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في أنظمة الطاقة، يتم تقسيم الإعداد بالكامل إلى مناطق محميه لعزل الأعطال وحماية بقية الشبكة. تشمل هذه المناطق المولدات والمحولات والحافلات وخطوط النقل وخطوط التوزيع والمحركات. يمكن تصور كل منطقة كغرفة منفصلة في المنزل، حيث يتم حماية كل غرفة بواسطة قاطع الدائرة الخاص بها.


تُعرَّف المناطق الوقائية بخطوط متقطعة مغلقة، تحتوي على مكون واحد أو أكثر. ومن السمات الرئيسية لهذه المناطق وضع قواطع الدائرة بشكل استراتيجي عند تقاطعات المناطق، مما يضمن إمكانية عزل أي عطل داخل المنطقة. على سبيل المثال، افترض حدوث عطل في منطقة مشابهة للمطبخ. في هذه الحالة، سيتم فتح قواطع الدائرة المرتبطة بهذه المنطقة، مما يؤدي إلى عزل العطل ومنعه من التأثير على مناطق أخرى.

يعد التداخل بين مناطق الحماية أمرًا بالغ الأهمية لضمان عدم ترك أي جزء من النظام دون حماية. يتم تحقيق هذا التداخل من خلال وجود مجموعتين من المحولات والمرحلات لكل قاطع دائرة، مما يوفر التكرار. يضمن هذا التكرار أنه حتى في حالة فشل أحد أجهزة الحماية، لا يزال بإمكان الجهاز الآخر توفير الحماية اللازمة، مما يعزز الموثوقية والسلامة العامة لنظام الطاقة. يسمح هذا الإعداد بعزل الأعطال بشكل فعال، والحفاظ على سلامة وكفاءة شبكة الطاقة بأكملها.

تتضمن خطط الحماية الفعّالة استخدام أنواع مختلفة من مرحلات الحماية، مثل المرحلات التفاضلية والمسافة والتيار الزائد، المصممة خصيصًا لتلبية احتياجات كل منطقة على حدة. تلعب أنظمة الاتصالات أيضًا دورًا حيويًا في تنسيق إجراءات أجهزة الحماية، مما يضمن عزل الأعطال بسرعة ودقة. من خلال تنفيذ هذه الاستراتيجيات، يمكن لأنظمة الطاقة تحقيق مستويات عالية من الموثوقية والسلامة، مما يقلل من الانقطاعات والأضرار الناجمة عن الأعطال.

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في أنظمة الطاقة ، ينقسم الإعداد بأكمله إلى مناطق واقية. إذا حدث خطأ داخل منطقة ما ، يتم عزله ، مما يحمي بقية النظام.
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Education

JoVE Core

Electrical Engineering

الهندسة الكهربائية

Unit 1

الوحدة الأولى

System Protection

حماية النظام

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الأساسية

power system protection zones

Power system protection zones divide the network into sections so faults can be isolated quickly. These zones can include generators, transformers, buses, transmission lines, distribution lines, and motors. Each zone is shown with closed dashed lines and contains one or more components.

Circuit breakers are placed at the borders where protection zones meet. If a fault happens in one zone, the related breakers open and disconnect only that section. A fault in one area, such as a kitchen in the house analogy, stays contained and does not spread to the rest of the system.

Overlap between zones is important because it helps keep every part of the network protected. This overlap is created by using two sets of instrument transformers and relays for each circuit breaker. That redundancy matters if one protection device fails, because the second one can still act and keep the system safe.

Different zones may use different protective relays, including differential relays, distance relays, and overcurrent relays. Communication systems also help these devices work together so faults are cleared quickly and accurately. Together, these protection strategies improve reliability, limit damage, and help maintain the integrity and efficiency of the power network.

Power System Protection Zones

instrument transformers

Voltage and Current Sensing in Power Grids

Instrument transformers help power substations measure voltage and current safely. They create isolated replicas of electrical signals for measurement and protection. These devices support protective relays and other monitoring equipment that keep power systems stable and reliable. The two main types are voltage transformers, or VTs, and current transformers, or CTs. A voltage transformer reduces the primary voltage to a lower level that relays and measuring devices can use. A current...

overcurrent relays

Relay Settings for Circuit Fault Protection

Overcurrent relays protect circuits by sensing excess current through the secondary side of a current transformer. They are an important part of circuit protection and help keep power systems stable when a fault occurs. Two main relay types are used here: instantaneous and time-delay overcurrent relays. An instantaneous relay trips right away when current rises above the pickup current, which is the preset level that starts the relay. It then energizes the circuit breaker trip coil at once,...

radial system protection

Breaker Coordination in Radial Systems

Breaker coordination in radial systems uses time-delay overcurrent relays to limit load interruption. When a fault happens, the nearest breaker should open first. Upstream breakers stay closed because they are set with longer delays. This lets the fault be isolated while the rest of the system keeps running. If a fault is downstream of the third breaker, only the third breaker should trip. That removes power from the load beyond the fault. The second breaker keeps a longer delay setting, so...

reclosers and fuses

Fault Coordination with Reclosers and Fuses

Fault coordination with reclosers and fuses helps protect radial distribution circuits. A recloser is an automatic switch that interrupts AC power and then closes again on a preset schedule. This brief outage can clear temporary faults on overhead lines, such as those caused by tree limbs or wildlife, and it can improve overall reliability. Reclosers and their ground-level hazards also matter. Contact with a recloser or with a broken energized conductor on the ground can be dangerous. That is...

directional relays

Directional Relays in Power System Protection

Directional relays help protect power systems by telling forward faults from reverse faults. They are used when fault current flows mainly in one direction on a line. This makes the relay useful for safe and efficient fault clearing. On a protected line, a fault downstream, or to the right of the current transformer, usually makes the fault current lag the bus voltage by about 90 degrees. This is called the forward direction. A fault upstream, or to the left, may make the fault current lead...

zones of protection

Power system protection zones divide the network into sections so faults can be isolated quickly. These zones can include generators, transformers, buses, transmission lines, distribution lines, and motors. Each zone is shown with closed dashed lines and contains one or more components. Circuit breakers are placed at the borders where protection zones meet. If a fault happens in one zone, the related breakers open and disconnect only that section. A fault in one area, such as a kitchen in the...

line protection with impedance relays

Impedance Relays for Fault Detection

Impedance relays help protect power lines by watching the voltage-to-current ratio on a line. They measure the apparent impedance, which is the electrical opposition the relay sees at that point in the system. This makes them useful when time-delay overcurrent relays are hard to coordinate in complex radial systems and when directional overcurrent relays are difficult to use in multi-source transmission loops. These relays respond strongly during a fault. As current rises and voltage falls,...

differential relays

Differential Relay Protection in Power Systems

Differential relays protect generators, buses, and transformers by comparing currents at different points in a power system. When the currents do not match, the relay detects the difference and opens the circuit breaker. Under normal conditions, the current entering a generator, i1, equals the current leaving it, i2. If a fault occurs, these currents become unequal, and the difference current flows through the relay operating coil to trip the relay. An electromechanical differential relay is...

pilot and numeric relaying

Pilot Relays and Digital Protection

Pilot relays and numeric relays help protect power systems. Pilot relaying is a form of differential protection, which compares electrical quantities at equipment terminals through a communication channel instead of a direct relay link. It is especially useful for transmission lines with terminals far apart, often up to 80 km on 69 to 115 kV lines. Pilot relaying can use several communication channels. Pilot wires are separate electrical circuits that operate at DC, 50 to 60 Hz, or audio...

key terms and concepts

Explore how power system protection zones use circuit breakers, overlapping relays, and communication to isolate faults and protect generators, lines, and motors.

Power System Protection Zones | JoVE K12

JoVE Core Electrical Engineering offers easy-to-understand animated videos that cover fundamental concepts of electric circuits along with circuit analysis techniques. It incorporates first-order and second-order circuits using operational amplifiers and circuit transformation concepts. The inclusion of practical design examples and real-world applications through scientist-in-action videos adds significant educational value, making complex concepts accessible.

electrical engineering

Power System Protection Zones

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