Name: balanced wye-to-wye neutral current
Uploaded: 2024-07-08T13:19:57.000Z
Duration: 1 min 19 s
Channel: JoVE

Dengeli dört telli Y'den Y'ye sistemler, kaynağın her iki nötr düğümünü yük ile birbirine bağlayan nötr tel ile üç dengeli Y bağlantılı sinüzoidal voltaj kaynağından ve yüklerden oluşur.
Her faz için yük empedansı, kaynak, hat ve yük empedanslarının toplamına eşittir. Sistemi basitleştirmek için kaynak ve hat empedansları ihmal edilir.
Pozitif faz sırası göz önüne alındığında, faz gerilimleri üç hatlı gerilimleri belirler
Kirchhoff'un Gerilim Yasası her faza uygulanır ve hat akımlarının eşit büyüklüklere ve 120 derecelik faz farklılıklarına sahip olduğu belirlenir.
Toplamları sıfıra eşittir, bu da nötr telde sıfır akım anlamına gelir.
Dengeli bir Y sisteminde, üç fazlı yüke iletilen toplam güç, her fazda sağlanan gücün üç katıdır.
Dengesiz bir yüke sahip dengesiz bir Y'den Y'ye sistem için, hat akımları dengesizdir ve bu da sıfır olmayan bir nötr akıma neden olur.
Dengeli bir Y'den Y'ye sistemi analiz etmenin başka bir yöntemi, bir fazı düşünmek ve hat akımını belirlemek için tek fazlı eşdeğer devresini analiz etmektir. Faz sırası daha sonra diğer iki hat akımını verir.

yıldız-yıldız (y-y) devresi

Dengeli bir dört telli yıldız-yıldız sisteminde, düzenleme, kaynağın ve yükün nötr düğümlerini birbirine bağlayan nötr bir tel aracılığıyla bağlanan yıldız-bağlantılı sinüzoidal voltaj kaynaklarını ve yükleri içerir. Yük empedansı yükün her fazına bağlanır. Yıldız bağlantılı kaynak, yıldız bağlantılı yüke dört telli ve üç telli düzenlemelerle bağlanabilir. Üç fazlı bir sistemin, her fazdaki yük eşit olduğunda dengeli olduğu kabul edilir; bu, tüm aşamalarda eşit akım akışına ve faz açısına yol açar. Öte yandan dengesiz bir sistemde yük empedansındaki veya kaynak gerilimlerindeki değişiklikler eşit olmayan hat akımlarına neden olur.

Dört telli yıldız-yıldız devre konfigürasyonunun analizi nispeten basittir. Bu kurulumda, üç fazlı yükün her bir empedansı, üç fazlı kaynaktan gelen ilgili faz voltajına doğrudan bağlanır. Pozitif faz sırası ve dengeli koşullar varsayıldığında, faz gerilimleri sistemin analizinde etkilidir. Bu faz gerilimleri, her yük empedansındaki gerilimleri doğrudan etkiler.

<img alt="Equation 1" src="/files/ftp_upload/15129/15129_Equation_1.svg" style="height: 32px;">

<img alt="Equation 2" src="/files/ftp_upload/15129/15129_Equation_2.svg" style="height: 32px;">

<img alt="Equation 3" src="/files/ftp_upload/15129/15129_Equation_3.svg" style="height: 32px;">

Kaynağın nötr ucunu yükün nötr ucuna bağlayan kablodaki akım şöyledir:

<img alt="Equation 4" src="/files/ftp_upload/15129/15129_Equation_4.svg" style="height: 16px;">

Kirchhoff'un Gerilim Yasası, dengeli bir üç fazlı devrenin her fazına uygulandığında, herhangi bir kapalı döngü etrafındaki gerilimlerin toplamının sıfır olduğunu doğrular. Bu, eşit büyüklükte ancak aralarında 120 derecelik faz kaymaları olan hat akımlarına yol açar. Bu akımların toplamı herhangi bir noktada etkili bir şekilde sıfıra ulaşır; bu da nötr telin dengeli koşullar altında neden akım taşımadığını haklı çıkarır.

Dengesiz bir yıldız-yıldız sisteminde, yük empedansındaki veya kaynak gerilimlerindeki değişiklikler eşit olmayan hat akımlarına neden olur. Sistemdeki her faz, hat akımını hesaplamak için tek fazlı bir devre olarak ele alınır. Bununla birlikte, geri kalan fazlar için olan akımlar, yalnızca fazların sırasına dayalı olarak çıkarım yapmak yerine bireysel analiz gerektirir; çünkü her faz, kendine özgü elektrik koşullarından benzersiz şekilde etkilenebilir.

Yıldız-Yıldız (Y-Y) Devresi

Dengeli dört telli Y'den Y'ye sistemler, üç dengeli Y'ye bağlı sinüzoidal voltaj kaynağından ve her ikisini de birbirine bağlayan nötr tel ile yüklerden oluşur.

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Electrical Engineering

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Unit 1

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Three-Phase Circuits

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TEMEL TERİMLER VE KAVRAMLAR

The Y-to-Y Circuit

balanced wye-to-wye neutral current

A balanced wye-to-wye circuit uses three wye-connected sinusoidal voltage sources and three wye-connected loads. A neutral wire links the neutral node of the source to the neutral node of the load. The load impedance is connected across each phase of the load.

The source and load can be connected in either a four-wire or a three-wire arrangement. A three-phase system is balanced when each phase has the same load. In that case, the current flow and phase angle are uniform across the system. If the load impedance or source voltages differ, the system becomes unbalanced and the line currents are no longer equal.

The four-wire wye-wye circuit is relatively easy to analyze. Each load impedance is connected directly across its own phase voltage from the three-phase source. With a positive phase sequence and balanced conditions, the phase voltages are the key to finding the voltages across each load impedance.

Kirchhoff's Voltage Law applies to each phase of a balanced three-phase circuit. The sum of the voltages around any closed loop is zero. This produces line currents with equal magnitude and 120-degree phase shifts. Their sum is zero at any point, so the neutral wire carries no current when the system is balanced.

An unbalanced wye-to-wye system must be treated differently. Changes in load impedance or source voltages create unequal line currents. Each phase is handled as a single-phase circuit to find its line current. The other phases must be analyzed on their own, since each one may be affected by its specific electrical conditions rather than by phase sequence alone.

Balanced Wye-to-Wye Neutral Current

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the y-to-y circuit

A balanced wye-to-wye circuit uses three wye-connected sinusoidal voltage sources and three wye-connected loads. A neutral wire links the neutral node of the source to the neutral node of the load. The load impedance is connected across each phase of the load. The source and load can be connected in either a four-wire or a three-wire arrangement. A three-phase system is balanced when each phase has the same load. In that case, the current flow and phase angle are uniform across the system. If...

the y-to-delta circuit

Wye Source and Delta Load Currents

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the delta-to-delta circuit

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A balanced delta-wye circuit connects a delta-connected source to a wye-connected load. In this setup, the phase voltage of the delta source equals the line voltage of the wye load. The source also sets the line currents that flow into the load. For a balanced system, the phase difference between currents makes it possible to find one line current from the other by using the positive sequence of phases. In the wye-connected load, each phase current equals the line current from the delta source.

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key terms and concepts

Learn how balanced and unbalanced wye-to-wye circuits work, why the neutral wire carries no current in balanced conditions, and how line currents are analyzed.

Balanced Wye-to-Wye Neutral Current | JoVE K12

JoVE Core Elektrik Mühendisliği, devre analizi teknikleriyle birlikte elektrik devrelerinin temel kavramlarını kapsayan, anlaşılması kolay animasyonlu videolar sunar. Operasyonel amplifikatörler ve devre dönüşümü kavramlarını kullanarak birinci dereceden ve ikinci dereceden devreleri içerir. Pratik tasarım örneklerinin ve gerçek dünya uygulamalarının bilim insanlarınca hazırlanan videolar aracılığıyla dahil edilmesi, karmaşık kavramları erişilebilir hale getirerek önemli bir eğitim değeri katmaktadır.

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Balanced Wye-to-Wye Neutral Current

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