Name: finding voltage and impedance in circuit a
Uploaded: 2025-05-22T09:06:14.000Z
Duration: 1 min 18 s
Channel: JoVE

System dystrybucji energii elektrycznej w gospodarstwie domowym, który obejmuje linie dystrybucyjne i transformatory, można uznać za sieć źródłową.
Wewnątrz domu różne urządzenia elektryczne mogą być reprezentowane jako impedancje obciążenia.
Twierdzenie Thévenina upraszcza ten złożony system dystrybucji do równoważnego obwodu Thévenina.
Znalezienie obwodu równoważnego Thévenin wymaga znajomości dwóch parametrów: napięcia Thévenin i impedancji Thévenin.
Aby zrozumieć proces ich określania, rozważ uproszczony obwód RLC podłączony do źródła napięcia.
Aby obliczyć impedancję Thévenin, wymień źródło napięcia na zwarcie i określ równoważną impedancję obwodu.
Napięcie Thévenin jest równe napięciu obwodu otwartego, co odpowiada spadkowi napięcia na równoległej gałęzi obwodu.
Początkowo obliczany jest prąd przepływający przez zamkniętą siatkę obwodu. Następnie za pomocą prawa Ohma określa się spadek napięcia na gałęzi równoległej, co daje napięcie Thévenina.
Jeśli obwód ma źródła pracujące na różnych częstotliwościach, obwód równoważny Thévenin oraz impedancje kondensatorów i cewek indukcyjnych należy określić osobno dla każdej częstotliwości.

obwody równoważne thévenina

Sieć podstawową stanowi przydomowy system dystrybucji energii, obejmujący linie dystrybucyjne i transformatory. Urządzenia elektryczne w gospodarstwie domowym można przedstawić jako impedancję obciążenia. Aby uprościć ten skomplikowany system dystrybucji, twierdzenie Thévenina można zastosować do utworzenia równoważnego obwodu Thévenina. Jeśli obwód prądu przemiennego jest podzielony na dwie części (obwód A i obwód B), połączone pojedynczą parą zacisków, jak pokazano na Figure 1.

<img alt="Figure1" src="/files/ftp_upload/15113/15113_PT_Figure_1.svg" style="text-align: center; height: 140px;" />

Figure 1: Obwód podzielony na dwie części Figure 2: Obwód A zamieniony na jego równoważny obwód Thévenina.

Zastąpienie obwodu A jego równoważnym obwodem Thévenina (źródłem napięcia w szereg z impedancją) nie zmienia prądu ani napięcia żadnego elementu w obwodzie B (pokazanym na Figure 2). Wartości prądów i napięć wszystkich elementów obwodu w obwodzie B będą takie same, niezależnie od tego, czy obwód B jest połączony z obwodem A, czy jego równoważnym obwodem Thévenina. Do znalezienia równoważnego obwodu Thévenina wymagane są dwa parametry: napięcie Thévenina oraz impedancja Thévenina. Figure 3 pokazuje obwód otwarty połączony z zaciskami obwodu A w celu określenia napięcia otwartego Voc, podczas gdy Figure 4 wskazuje, że impedancja Thévenina Zt jest równoważną impedancją obwodu A*.

<img alt="Figure2" src="/files/ftp_upload/15113/15113_PT_Figure_2.svg" style="text-align: center; height: 150px;" />

Figure 3: Obwód równoważny Thévenina z Voc. Figure 4: Obwód równoważny Thévenina przedstawiający Zt. .

Obwód A* jest utworzony z obwodu A poprzez zastąpienie wszystkich niezależnych źródeł napięcia zwarciami i wszystkich niezależnych źródeł prądu obwodami otwartymi. Ogólnie rzecz biorąc, impedancję Thévenina Zt można wyznaczyć poprzez wielokrotne zastąpienie impedancji szeregowych lub równoległych równoważnymi impedancjami.

Obwody równoważne Thévenina

System dystrybucji energii elektrycznej w gospodarstwie domowym, który obejmuje linie dystrybucyjne i transformatory, można uznać za sieć źródłową.
Wewnątrz domu ...

Education

JoVE Core

Electrical Engineering

Elektrotechnika

Unit 1

Jednostka 1

AC Circuit Analysis

Analiza obwodów prądu przemiennego

KEY TERMS AND CONCEPTS

Kluczowe terminy i pojęcia

Th&#233venin Equivalent Circuits

finding voltage and impedance in circuit a

The household power distribution system can be simplified with Thevenin's theorem. In this system, distribution lines and transformers form the main network. Electrical appliances can be treated as load impedance, which makes the circuit easier to analyze.

An AC circuit can be split into two parts, circuit A and circuit B, with a single pair of terminals between them. Circuit A can then be replaced by its Thevenin equivalent circuit. That equivalent has a voltage source in series with an impedance.

Replacing circuit A with its Thevenin equivalent does not change the current or voltage of any element in circuit B. The values in circuit B stay the same whether it is connected to the original circuit A or to the Thevenin equivalent. This is why the method is useful for studying connected circuits.

Two values are needed to build the Thevenin equivalent circuit. The first is the Thevenin voltage, which is found from the open-circuit voltage across the terminals of circuit A. The second is the Thevenin impedance, Zt, which is the equivalent impedance of circuit A*.

To form circuit A*, all independent voltage sources are replaced with short circuits. All independent current sources are replaced with open circuits. Then series or parallel impedances can be combined repeatedly to find Zt.

Finding Voltage and Impedance in Circuit A

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Finding Voltage and Impedance in Circuit A

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