Abstract: An apparatus includes an interface receiving a plurality of voltage measurements that include one combination of a first voltage measurement and a second voltage measurement; a first voltage measurement at a first tap point of a shunt capacitor bank; a second voltage measurement at the bus, wherein the shunt capacitor system is a single y-connected shunt capacitor bank comprising the shunt capacitor bank; a first voltage measurement at a first tap point of a first y-connected branch; a second voltage measurement at a second tap point of a second y-connected branch; wherein the shunt capacitor system is a double y-connected shunt capacitor bank comprising the first y-connected branch and the second y-connected branch; and, a fault identifier identifying a simultaneous fault of the shunt capacitor system based upon a temporal evolution of the first and second voltage measurements.

Abstract: A system and method for detecting location of fault in a cable receives disturbance data from first and second protection relays when one of the first protection relay and/or the second protection relay detects a fault in a section of the cable. The system extracts voltage and current data for each segment in the section using the disturbance data, cable parameters and length of each segment, and determines a fitness value for each segment in the section using the extracted voltage and current data. The system identifies a segment with a lowest fitness value from the fitness value determined for each segment in the section by comparing the fitness value of each segment with the fitness value of subsequent segments in the section and detects the segment with the lowest fitness value as fault location in the cable.

Abstract: Embodiments of present disclosure provides methods for determining a fault of a power system. Methods include estimating, based on measured electrical quantities at a first position of a power line in the power system, voltages at a second position of the power line, the measured electrical quantities being associated with three phases of the power system and comprising voltages at the first position of the power line. The methods include determining at least one phase angle between the voltages at the first position and the estimated voltages at the second position, and detecting the fault based on the at least one phase angle during a power swing. In a method according to the present disclosure, a three-phase fault during a power swing is identified in a shorter time, and thus the tripping is performed with a faster speed.

Abstract: A system and method for detecting stator inter-turn fault in induction machines includes receiving a time series data of a stator current using a plurality of current sensors connected to a stator of the induction machine, determining first and second signature time series data of stator current using fundamental components and harmonic components of the stator current, determining first and second scaled signatures using an Unbalance Factor, determining a discrimination factor, and detecting a stator inter-turn fault when the discrimination factor is greater than a predetermined stator inter-turn fault threshold value.

Abstract: A method and a system for controlling an on-load tap changer of a transformer during reverse power flow includes determining a loss ratio factor using voltage and current values for each of a primary side and a secondary side of a transformer. Further, the method comprises determining a relative strength of a first source connected to the primary side and a second source connected to the secondary side of the transformer based on the loss ratio factor. Thereafter, transmitting a control signal to an on-load tap changer of the transformer to regulate voltage on the primary side or on the secondary side of the transformer based on the relative strength of the first source and the second source.

Abstract: A system and method for detecting location of fault in a cable receives disturbance data from first and second protection relays when one of the first protection relay and/or the second protection relay detects a fault in a section of the cable. The system extracts voltage and current data for each segment in the section using the disturbance data, cable parameters and length of each segment, and determines a fitness value for each segment in the section using the extracted voltage and current data. The system identifies a segment with a lowest fitness value from the fitness value determined for each segment in the section by comparing the fitness value of each segment with the fitness value of subsequent segments in the section and detects the segment with the lowest fitness value as fault location in the cable.

Abstract: The present disclosure discloses a device and a method for condition monitoring and protection of rotating electrical motors. The device receives measurements of current flowing in a power line connected to the rotating electrical machine. The device extracts a frequency band content containing information representative of condition of rotor bar from the measured current signal using wavelet filters. Further, the device compares the frequency band contents with a predefined threshold value and identifies a condition of the rotor bars. The condition includes damages caused to the rotor bars. Based on the condition, the IED generates one or more status signals (alarm signals or trip signals). The trip signal is provided to a switch connected to the power line to disconnect the rotating electrical machine.

Abstract: The present disclosure discloses a device and a method for condition monitoring and protection of rotating electrical motors. The device receives measurements of current flowing in a power line connected to the rotating electrical machine. The device extracts a frequency band content containing information representative of condition of rotor bar from the measured current signal using wavelet filters. Further, the device compares the frequency band contents with a predefined threshold value and identifies a condition of the rotor bars. The condition includes damages caused to the rotor bars. Based on the condition, the IED generates one or more status signals (alarm signals or trip signals). The trip signal is provided to a switch connected to the power line to disconnect the rotating electrical machine.

Abstract: A method for generating corrected measured current in an Intelligent Electronic Device (IED) that is a true representation of primary current in an electrical network is disclosed. The method uses regression and a first threshold on measured sampled values from CT to detect a deviation instance that indicates a possibility of saturation. Wavelet and second threshold based detection of instances of saturation is then done. Then a regression based correction that uses a dynamic correction factor is implemented in real time to obtain corrected sampled values i.e. corrected measured current. Ending of correction is done based upon a predetermined selection criterion, The generated corrected measured current is used for protection and control functions in the IED. A CT output re-generation module as a functional module in the IED for implementing the method as described above is also disclosed.

Abstract: A method for generating corrected measured current in an Intelligent Electronic Device (IED) that is a true representation of primary current in an electrical network is disclosed. The method uses regression and a first threshold on measured sampled values from CT to detect a deviation instance that indicates a possibility of saturation. Wavelet and second threshold based detection of instances of saturation is then done. Then a regression based correction that uses a dynamic correction factor is implemented in real time to obtain corrected sampled values i.e. corrected measured current. Ending of correction is done based upon a predetermined selection criterion, The generated corrected measured current is used for protection and control functions in the IED. A CT output re-generation module as a functional module in the IED for implementing the method as described above is also disclosed.