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

전력 시스템에서는 전체 설정이 보호 구역으로 나뉩니다. 영역 내에서 오류가 발생하면 격리되어 시스템의 나머지 부분을 보호합니다.
이러한 영역에는 발전기, 변압기, 버스, 송전 및 배전선, 모터가 포함됩니다. 이것을 각각 회로 차단기로 보호되는 집의 다른 방으로 생각하십시오.
각 방 또는 구역은 닫힌 점선으로 정의됩니다. 각 방 안에는 하나 이상의 구성 요소가 있을 수 있습니다.
이러한 보호 구역의 고유한 특성에는 중첩 및 회로 차단기 배치가 포함됩니다. 회로 차단기는 이러한 방의 교차점에 서 있는 경비원과 같아서 문제가 발생하는 모든 방을 격리합니다.
따라서 부엌에 결함이 발생하면 부엌에 연결된 모든 회로 차단기가 열려 부엌을 격리하고 결함이 다른 방에 영향을 미치는 것을 방지합니다.
겹치는 구역은 인접한 방 사이에 두 개의 문을 두어 보호되지 않은 영역이 없도록 하므로 하나가 실패하더라도 다른 하나가 계속 보호할 수 있습니다.
오버랩은 각 회로 차단기에 대해 두 개의 계기 변압기와 릴레이를 사용하여 달성됩니다.

보호 구역

Zones of Protection

전력 시스템에서 전체 설정은 오류를 격리하고 나머지 네트워크를 보호하기 위해 보호 구역으로 나뉩니다. 이러한 구역에는 발전기, 변압기, 버스, 송전선, 배전선 및 모터가 포함됩니다. 각 구역은 집 안의 별도 방으로 시각화할 수 있으며, 각 방은 자체 회로 차단기로 보호됩니다.

보호 구역은 하나 이상의 구성 요소를 포함하는 닫힌 점선으로 정의됩니다. 이러한 구역의 주요 특징은 구역 교차점에 회로 차단기를 전략적으로 배치하여 구역 내의 모든 결함을 격리할 수 있다는 것입니다. 예를 들어, 주방과 유사한 구역에서 결함이 발생한다고 가정해 보겠습니다. 이 경우 해당 구역과 관련된 회로 차단기가 열려 결함을 격리하고 다른 구역에 영향을 미치지 않도록 합니다.

보호 구역 간의 중복은 시스템의 어느 부분도 보호되지 않은 채로 두지 않도록 하는 데 중요합니다. 이 중복은 각 회로 차단기에 두 세트의 계기 변압기와 릴레이를 두어 중복성을 제공함으로써 달성됩니다. 이 중복성은 한 보호 장치가 고장나더라도 다른 장치가 여전히 필요한 보호를 제공할 수 있도록 하여 전력 시스템의 전반적인 안정성과 안전성을 향상시킵니다. 이 설정은 오류를 효과적으로 격리하여 전체 전력 네트워크의 무결성과 효율성을 유지할 수 있게 합니다.

효과적인 보호 계획에는 차동, 거리 및 과전류 릴레이와 같은 다양한 유형의 보호 릴레이를 사용하여 각 구역의 특정 요구 사항에 맞게 조정하는 것이 포함됩니다. 통신 시스템은 또한 보호 장치의 동작을 조정하여 빠르고 정확한 오류 격리를 보장하는 데 중요한 역할을 합니다. 이러한 전략을 구현함으로써 전력 시스템은 높은 수준의 신뢰성과 안전성을 달성하여 오류로 인한 중단 및 손상을 최소화할 수 있습니다.

전력 시스템에서는 전체 설정이 보호 구역으로 나뉩니다. 영역 내에서 오류가 발생하면 격리되어 시스템의 나머지 부분을 보호합니다.
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Education

JoVE Core

Electrical Engineering

Unit 1

System Protection

KEY TERMS AND CONCEPTS

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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