Name: delta-wye source and load connections
Uploaded: 2024-07-08T13:19:57.000Z
Duration: 1 min 16 s
Channel: JoVE

평형 델타-Y 시스템은 평형 Y 연결 부하에 전력을 공급하는 평형 델타 연결 소스를 특징으로 합니다.
이 델타-Y 회로에서 양의 abc 시퀀스는 위상 전압을 표현하는 것으로 간주되며, 이는 델타 연결 소스의 라인 전압 역할도 합니다.
Kirchhoff의 전압 법칙은 회로의 루프에 적용하여 두 라인 전류 사이의 관계를 유도 할 수 있습니다.
양의 시퀀스가 가정되기 때문에 이러한 라인 전류는 120도의 위상차를 가지며 이는 그 중 하나를 결정하는 데 사용됩니다.
다른 두 라인 전류는 양의 위상 시퀀스를 사용하여 얻습니다.
delta-Y 회로의 위상 전류는 라인 전류와 거의 같습니다.
또는 델타 연결 소스를 동등한 Y 연결 소스로 교체할 수 있습니다.
얻어진 Y-Y 회로는 등가 단상 회로를 고려하고 3선 전류를 결정하여 분석됩니다.
이 회로는 개별 부하를 쉽게 변경할 수 있기 때문에 델타 연결 부하가 선호되는 경우가 많기 때문에 분석 목적으로 델타-델타 시스템으로 변환할 수도 있습니다.

델타-와이 회로

델타-와이 회로에서 소스는 델타 연결되고 부하는 와이 구성에 있습니다. 이는 델타 연결 소스의 위상 전압이 Y연결 부하의 라인 전압과 동일함을 의미합니다. 2선 전류 간의 연결은 델타 연결 소스에서 시작됩니다. 균형 잡힌 시스템의 위상차를 통해 양의 위상 시퀀스를 활용하여 한 라인 전류를 다른 라인 전류에 계산할 수 있습니다. 델타-와이 회로에서는 델타 소스로부터의 흐름을 단순화하는 부하의 Y 구성으로 인해 Y로 연결된 부하의 위상 전류가 델타 소스의 라인 전류와 직접적으로 동일합니다. Y형 구성의 선전류와 위상 전류 간의 관계는 Y형 연결 부하의 위상 전류가 델타 연결 소스의 선전류와 동일하다는 것을 보여줍니다.
라인 전류를 얻는 또 다른 방법은 델타 연결 소스를 동등한 Wye 연결 소스로 교체하는 것입니다. Y형으로 연결된 소스의 선간 전압은 해당 위상 전압보다 30도 앞섭니다. 이는 등가 Y 연결 소스의 각 위상 전압이 델타 연결 소스의 해당 라인 전압을 3의 제곱근으로 나누고 해당 위상을 -30도 이동하여 얻어짐을 의미합니다. 결과적으로 등가 Y 연결 소스는 그에 따라 120도만큼 이동된 위상 전압을 갖게 됩니다.
델타 구성을 스타 구성으로 변환하면 시스템에서 더 나은 전압 조정을 달성하고 중성선을 사용할 수 있습니다. 이 중성선은 시스템의 접지를 가능하게 하여 안전성과 안정성을 향상시킵니다.
균형 잡힌 델타-델타 구성은 산업용, 상업용 및 주거용으로 사용할 수 있는 수준으로 고전압 레벨을 낮추어야 하는 장거리에 걸쳐 전기를 전송하는 데 사용됩니다.

평형 델타-Y 시스템은 평형 Y 연결 부하에 전력을 공급하는 평형 델타 연결 소스를 특징으로 합니다.
이 델타-Y 회로에서 양의 abc ...

Education

교육

JoVE Core

Electrical Engineering

전기공학

Unit 1

제1단원

Three-Phase Circuits

3상 회로

KEY TERMS AND CONCEPTS

주요 용어 및 개념

The Delta-to-Y Circuit

delta-wye source and load connections

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. That relationship makes current analysis simpler in the load section.

The line currents can also be found by replacing the delta source with an equivalent wye source. In that conversion, each phase voltage is the matching line voltage divided by the square root of three and shifted by -30 degrees. The line-to-line voltages of a wye source lead the phase voltages by 30 degrees, so the equivalent wye source keeps the phases spaced 120 degrees apart.

Changing a delta connection to a star, or wye, connection can improve voltage regulation. It also allows the use of a neutral wire. That neutral wire supports grounding, which improves safety and stability. Balanced delta systems are also used for long-distance power transmission, where high voltage must later be stepped down for industrial, commercial, and residential use.

Delta-Wye Source and Load Connections

three-phase circuits

How Three-Phase Power Delivers Electricity

Three-phase power is a major part of AC power distribution, especially where steady and efficient electricity delivery is needed. AC systems are grouped into single-phase, two-phase, and three-phase systems. These categories help describe how power moves from the source to the load. Single-phase circuits are common in homes. They usually use a two-wire system that connects one AC source to loads. These circuits can supply everyday appliances such as lamps, televisions, and microwaves at 120 V...

generation of three-phase voltage

Three-Phase AC Generator Windings

A three-phase AC generator uses rotating magnet windings and a stationary stator to make three-phase voltage. The rotor carries a magnet that spins inside the stator. The stator holds the three-phase winding, and mutual induction creates the voltage. The stator windings are spread evenly around the inside of the stator. They are placed 120 electrical degrees apart. These windings consist of three separate coils, or groups of coils, called phases. The phases can be connected in a Y, or star,...

three-phase voltages

Three-Phase Power Connections

Three-phase power connections use balanced voltages that are equal in magnitude and separated by 120 degrees. A three-phase generator produces these voltages, and the balance helps reduce power loss while keeping energy delivery steady to connected loads. Three-phase sources can be arranged in either wye or delta form. The loads connected to the system can also use wye or delta. This flexibility gives control over how the system is designed and managed. In a wye connection, one end of each...

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 y-to-delta circuit

Wye Source and Delta Load Currents

A balanced wye source and delta load form a common three-phase circuit with no neutral line connection. The source is Y-connected, and the load is delta-connected. To analyze the circuit, the first step is to assume a positive phase sequence. These phase voltages are then used to find the line voltages that appear across the delta load impedances. In the wye source, the phase voltages are V an, V bn, and V cn. In the delta load, the line voltages are V ab, V bc, and V ca. These line voltages...

the delta-to-delta circuit

Balanced Delta-Delta Power Circuit

A balanced delta-delta power circuit uses a delta-connected source and a delta-connected load. The two deltas form a closed loop that creates three separate phases. In this setup, the phase voltages are the same as the line voltages. If the source is in positive sequence, the phase voltages can be written directly, and no neutral wire is needed. The delta-connected load current is found by dividing the phase voltage by the impedance of each phase. For line current, Kirchhoff’s Current Law...

the delta-to-y circuit

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.

power in a three-phase circuit

Balanced Three-Phase Power Calculation

Balanced three-phase power calculation depends on the wye and delta connections used in the circuit. A wye, or star, configuration can use three wires or four wires. A delta configuration connects the components in a closed loop. These connection types change how voltages and currents are arranged, but both are used in three-phase systems. In a balanced three-phase system, instantaneous power is the power at one exact moment. Even though the power in each phase changes over time, the total...

power distribution in three-phase and single phase circuits

power-distribution-in-three-phase-and-single-phase-circuits

Single-Phase vs. Three-Phase Power Loss

Single-phase and three-phase circuits distribute electrical power in different ways. Single-phase power is common in homes, while balanced three-phase power is widely used in industrial settings with heavy machinery. Both systems deliver energy, but their current flow and wire needs are not the same. A single-phase circuit usually uses a two-wire system. The current depends on the power absorbed by the load and the line voltage. Because wire loss from resistance follows the square of the...

line loss

Reducing Power Loss in Three-Phase Lines

Three-phase power lines can lose energy as electricity travels from the source to the load. This line loss affects how efficiently power reaches the load. In balanced three-phase circuits, the symmetry makes the analysis easier because one phase can represent the whole system. The source-load connection can use wye, also called star, or delta configurations. These setups change the relationship between line voltage, phase voltage, line current, and phase current. A per-phase equivalent circuit...

reducing line loss

Cutting Heat Loss in Three-Phase Lines

Three-phase power systems can lose energy as heat in transmission lines because the wires have resistance. This line loss becomes important when electricity travels over a distance. A common solution is to use transformers to change the voltage and current in the system. The setup uses two three-phase transformers. A step-up transformer is placed at the source, and a step-down transformer is placed at the load. Raising the voltage at the source lowers the current in the transmission lines, and...

key terms and concepts

Learn how a balanced delta source powers a wye load, how line and phase currents relate, and how a delta source can be converted to an equivalent wye source.

Delta-Wye Source and Load Connections | 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

Delta-Wye Source and Load Connections

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