Load Flow Studies Practice Questions

A single-phase load is supplied by a single-phase voltage source. If the current flowing from the load to the source is $10\angle -150^{\circ}$ A and if the voltage at the load terminal is $100\angle 60^{\circ}$ V, then the

The bus admittance matrix of a three-bus three-line system is

If each transmission line between the two buses is represented by an equivalent $\pi$ -network, the magnitude of the shunt susceptance of the line connecting bus 1 and 2 is

A three-bus network is shown in the figure below indicating the p.u. impedance of each element. The bus admittance matrix, Y-bus, of the network is

Consider two buses connected by an impedence of $(0+j5)\Omega$ . The bus 1 voltage is 100 $\angle 30^{\circ}$ V, and bus 2 voltage is 100 $\angle 0^{\circ}$ V. The real and reactive power supplied by bus 1 respectively are

For the Y-bus matrix of a 4-bus system given in per unit, the buses having shunt elements are

Consider the two power systems shown in figure A below, which are initially not interconnected, and are operating in steady state at the same frequency. Separate load flow solutions are computed individually of the two systems, corresponding to this scenario. The bus voltage phasors so obtain are indicated on figure A. These two isolated systems are now interconnected by a short transmission line as shown in figure B, and it is found that $P_1=P_2=Q_1=Q_2=0$ . The bus voltage phase angular difference between generator bus X and generator bus Y after interconnection is

For a power System the admittance and impedance matrices for the fault studies are as fallows

The pre-fault voltages are 1.0 pu. at all the buses. The system was unloaded prior to the fault. A solid 3-phase fault takes place at bus 2. The per unit fault feeds from generators connected to buses 1 and 2 respectively are

For a power system the admittance and impedance matrices for the fault studies are as fallows

The pre-fault voltages are 1.0 pu. at all the buses. The system was unloaded prior to the fault. A solid 3-phase fault takes place at bus 2. The post fault voltages at buses 1 and 3 in per unit respectively are

The Gauss Seidel load flow method has following disadvantages. Tick the incorrect statement

The network shown in the given figure has impedances in p.u. as indicated. The diagonal element $Y_{22}$ of the bus admittance matrix $Y_{BUS}$ of the network is

The bus impedance matrix of a 4-bus power system is given by

A branch having an impedance of $j0.2 \Omega$ is connected between bus 2 and the reference. Then the values of $Z_{22,new}$ and $Z_{23,new}$ of the bus impedance matrix of the modified network are respectively

A power system consist of 300 buses out of which 20 buses are generator bus, 25 buses are the ones with reactive power support and 15 buses are the ones with fixed shunt capacitors. All the other buses are load buses. It is proposed to perform a load flow analysis in the system using Newton-Raphson method. The size of the Newton Raphson Jacobian matrix is

A power system consists of 2 areas (Area 1 and Area 2) connected by a single tie line. It is required to carry out a load flow study on this system. While entering the network data, the tie-line data (connectivity and parameters) is inadvertently left out. If the load flow program is run with this incomplete data