In a power system, each bus, or node is associated with how many quantities?
In a power system, each bus or node is associated with 4 quantities in the Newton-Raphson power flow method. These are:
Voltage magnitude (V): The magnitude of the voltage at the bus in volts.
Voltage phase angle (δ): The phase angle of the voltage at the bus with respect to some reference angle, usually taken as zero.
Real power injection (P): The net active power injection (or consumption) at the bus in megawatts.
Reactive power injection (Q): The net reactive power injection (or consumption) at the bus in megavolt-amperes reactive (MVAR).
These 4 quantities are known as the bus or node variables. In power system analysis using the Newton-Raphson method, the values of these variables are solved iteratively.