Question

Question:For the five bus system from Example 6.9, assume the transmission lines and transformers are modeled with just their per unit reactance (e.g., neglect their resistance and B shunt values). If bus one is assumed to be an infinite bus, what is the equivalent (Thevenin) reactance looking into the system from the bus three terminal? Neglect any impedances associated with the loads.

Short answer

Answer

The value of thevenin reactance looking into the system from bus three terminals is .

Step-by-step solution

Write the given data from the question.

As reference to figure 6.2 in example given 6.9 in the textbook.

The transmission lines and transformers for a five-bus system are modeled using their per-unit reactance. The infinite bus is Bus 1.As reference to example 11.3 in the textbook.

Step 2: Determine the formula of equivalent reactance, looking into the system from the bus three terminals.

Write the formula ofequivalent reactance, looking into the system from the bus three terminals.

${\mathbf{X}}_{\mathbf{Th}}={\mathbf{X}}_{\mathbf{34}}\mathbf{+}\left[{\mathbf{X}}_{\mathbf{45}}\parallel \left({\mathbf{X}}_{\mathbf{42}}\mathbf{+}{\mathbf{X}}_{\mathbf{25}}\right)\right]\mathbf{+}{\mathbf{X}}_{\mathbf{15}}$ …… (1)

Here, X₃₄ represent the reactance between bus 3 and bus4 ,X₄₅ , represent the reactance between bus4 and bus 2,X₂₅ represent the reactance between bus 4 and bus5 X₄₂ , represents the reactance between bus and bus and represent the reactance between bus 2 and bus 5 X₁₅ .

Determine the value of value of equivalent reactance, looking into the system from the bus three terminals.

For the circuit diagram in figure 1, calculate the equivalent reactance by approaching the system from three bus terminals.