, EEE4701 ASSIGNMENT 3
DUE DATE: 3 NOVEMBER 2026
QUESTION 1:
1.1
Power-system stability is the ability of an electrical power system to maintain an acceptable
operating condition following a disturbance and, where necessary, return to a stable
equilibrium state. Disturbances can include generator outages, transmission-line faults,
sudden changes in load, loss of generation or major switching operations. A stable power
system must maintain acceptable voltage, frequency and power-angle relationships
following such disturbances. IEEE describes stability as the ability of a power system to
regain a state of operating equilibrium after a physical disturbance while keeping the
important system variables within acceptable limits.
Power-system stability is commonly divided into several categories.
Transient stability refers to the ability of synchronous generators to remain in synchronism
following a large disturbance. Examples include three-phase faults, sudden loss of a
transmission line or the disconnection of a large generating unit. During a severe
disturbance, the electrical output of a generator can change rapidly while the mechanical
input from its turbine cannot change at the same rate. This produces an imbalance between
mechanical and electrical power, causing the rotor angle to change.
The swing equation can be written in simplified form as:
M(d²δ/dt²) = Pm - Pe
Where:
M = inertia-related constant
δ = rotor angle
Pm = mechanical input power
Pe = electrical output power
DUE DATE: 3 NOVEMBER 2026
QUESTION 1:
1.1
Power-system stability is the ability of an electrical power system to maintain an acceptable
operating condition following a disturbance and, where necessary, return to a stable
equilibrium state. Disturbances can include generator outages, transmission-line faults,
sudden changes in load, loss of generation or major switching operations. A stable power
system must maintain acceptable voltage, frequency and power-angle relationships
following such disturbances. IEEE describes stability as the ability of a power system to
regain a state of operating equilibrium after a physical disturbance while keeping the
important system variables within acceptable limits.
Power-system stability is commonly divided into several categories.
Transient stability refers to the ability of synchronous generators to remain in synchronism
following a large disturbance. Examples include three-phase faults, sudden loss of a
transmission line or the disconnection of a large generating unit. During a severe
disturbance, the electrical output of a generator can change rapidly while the mechanical
input from its turbine cannot change at the same rate. This produces an imbalance between
mechanical and electrical power, causing the rotor angle to change.
The swing equation can be written in simplified form as:
M(d²δ/dt²) = Pm - Pe
Where:
M = inertia-related constant
δ = rotor angle
Pm = mechanical input power
Pe = electrical output power
