Abstract:
To locate fault in power distribution system various methods are proposed which are
iterative and time consuming in nature. Therefore, to speed up the restoration process
and to improve reliability at consumer end a non-iterative and fast approach is presented
to locate the fault in power distribution system (PDS). This method is applicable to all
types of faults. It requires voltage and current measurement at substation node after
occurrence of fault and bus impedance matrix of healthy system. Current and Voltage
at local substation can be expressed as resistance of fault and location of fault by bus
impedance matrix, solution of which yields to fault location. This approach of fault
location is applicable to unbalanced system as it is developed in phase domain. It is
assumed that distribution system network topology and parameters are known through
which bus impedance matrix is developed. To calculate the pre fault bus voltages and
currents of each bus unbalanced three phase load flow is utilized which is different from
the conventional methods used for three phase balanced transmission system. It requires
BIBC (bus injection to branch current) and BCBV (branch current to bus voltage) matrix
and a simple matrix multiplication to acquire the appropriate results. Therefore,
it eliminates the need of forward/backward substitution of the Jacobian matrix or admittance
matrix used in the transmission system load flow methods. Utilizing load flow
results bus impedance matrix is developed and then algorithm for fault location is applied
to calculate the actual fault location. The method presented is fast, accurate and
robust for load variations.
