A single-phase power system consists of a 450-V 60-Hz generator supplying a load-bank consisting of three loads (L1, L2 and L3) through a transmission line of impedance Z line=0.22+j0.43 as shown in Figure 1. A transformer (T1) with turn ratio N1:N2 is connected in the source end. Another tapping transformer (T2) with turn ratio M1:M2 is connected in the load end with a switch (K1). The switch can be connected to any of the tapping location: a, b or c. The load bank is connected with the system through another switch (K2). This switch can be connected to any of the load: L1, L2 or L3. Only one load can be connected at a time. There is a Control Box (C.B.) in between K1 and K2. It is designed in a way that if K2 is connected with a load (L1, L2 or L3) based on the demand of the consumer, it will trigger K1 to connect with any of the tap of T2 (a, b or c), based on the required power by the load. Consider that the power loss in the CB is negligible Load 1 (L1): Light load, 200W rating,ZL1=4+j3ohms , Load 2 (L2): Medium load, 800W rating,ZL2=3+j4ohms , Load 3 (L3): Heavy load, 1.2KW rating,ZL3=4+j2ohms N1: N2 = Turn ratio for T1 M1: M2 = Turn ratio for T2
Load flow analysis
Load flow analysis is a study or numerical calculation of the power flow of power in steady-state conditions in any electrical system. It is used to determine the flow of power (real and reactive), voltage, or current in a system under any load conditions.
Nodal Matrix
The nodal matrix or simply known as admittance matrix, generally in engineering term it is called Y Matrix or Y bus, since it involve matrices so it is also referred as a n into n order matrix that represents a power system with n number of buses. It shows the buses' nodal admittance in a power system. The Y matrix is rather sparse in actual systems with thousands of buses. In the power system the transmission cables connect each bus to only a few other buses. Also the important data that one needs for have a power flow study is the Y Matrix.
Types of Buses
A bus is a type of system of communication that transfers data between the components inside a computer or between two or more computers. With multiple hardware connections, the earlier buses were parallel electrical wires but the term "bus" is now used for any type of physical arrangement which provides the same type of logical functions similar to the parallel electrical bus. Both parallel and bit connections are used by modern buses. They can be wired either electrical parallel or daisy chain topology or are connected by hubs which are switched same as in the case of Universal Serial Bus or USB.
A single-phase power system consists of a 450-V 60-Hz generator supplying a load-bank consisting of three loads (L1, L2 and L3) through a transmission line of impedance Z line=0.22+j0.43 as shown in Figure 1.
A transformer (T1) with turn ratio N1:N2 is connected in the source end.
Another tapping transformer (T2) with turn ratio M1:M2 is connected in the load end with a switch (K1). The switch can be connected to any of the tapping location: a, b or c.
The load bank is connected with the system through another switch (K2). This switch can be connected to any of the load: L1, L2 or L3. Only one load can be connected at a time.
There is a Control Box (C.B.) in between K1 and K2. It is designed in a way that if K2 is connected with a load (L1, L2 or L3) based on the demand of the consumer, it will trigger K1 to connect with any of the tap of T2 (a, b or c), based on the required power by the load.
Consider that the power loss in the CB is negligible
- Load 1 (L1): Light load, 200W rating,ZL1=4+j3ohms ,
- Load 2 (L2): Medium load, 800W rating,ZL2=3+j4ohms ,
- Load 3 (L3): Heavy load, 1.2KW rating,ZL3=4+j2ohms
- N1: N2 = Turn ratio for T1
M1: M2 = Turn ratio for T2
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