Question

The “dc” power flow solution, giving approximate answers, is based on completely neglecting the Q-V equation and solving the linear real-power balance equations.

(a) True (b) False

Short answer

The correct answer is (a) true.

Step-by-step solution

Definition of “dc” power flow solution.

On AC power networks, direct current load flow provides estimates of line power flows. Only active power flows are considered in direct current load flow, while reactive power flows are ignored. This method is non-iterative and convergent, although it is less accurate than AC Load flow solutions. Wherever repetitive and quick load flow calculations are necessary, direct current load flow is applied.

Determine the “dc” power flow solution method.

The dc power flow simplification is obtained by the fast decoupled power flow by neglecting the Q-V equation in the fast decoupled equations. Here, the magnitude of the voltage is constant at 1.0 per unit.

With reactive $X_{Jk}$, the power flow on the line from bus $J$ to bus $k$ becomes

${\mathrm{P}}_{\mathrm{jk}}=\frac{{\mathrm{\delta }}_{\mathrm{j}}-{\mathrm{\delta }}_{\mathrm{k}}}{{\mathrm{X}}_{\mathrm{jk}}}$

The real power balance equations also reduce to a linear problem.

$-\text{B}\delta =\text{P}$

Here, B is the imaginary component and ${\text{Y}}_{\text{bus}}$ is calculated by the line resistance.

Therefore, the given statement is True.