Hitachi Energy Switzerland Ag

Abb Schweiz Ag

Urmil Parikh

Michael Stanek

Anil Talluri

Anoop Parapurath

Soumya Kanta

A method for controlled switching of a circuit breaker is described. The method includes initiating operation of the circuit breaker at an initiation time derivable from an initiation time function by calculating a value of the initiation time function with respect to a command instant. The initiation time function is a sum of the command instant and a command delay time. The initiation time function depends on a first parameter and a second parameter. At least one of: the partial derivative of the initiation time function with respect to the first parameter is dependent on the second parameter or the partial derivative of the initiation time function with respect to the second parameter is dependent on the first parameter. Further, a system for controlled switching according to the method and a circuit breaker including the system are described.

Controlled switching of a circuit breaker

The invention relates to monitoring operation of a switching device in a power system, where a load is connected to a power source through the switching device. The load has windings, with coupling between at least one of two or more phases of a winding, and two or more windings of the load. The method includes obtaining measurements of at least one of voltages and currents, at one or more of a source and load side. Further, the method determines an electrical parameter associated with electrical switching of one or more poles. The parameter for each pole is determined based on at least one of voltage measurements at the source and load side, and line measurements associated with at least one winding. The values of the electrical parameter are monitored to determine the switching instant of the pole, for determining mechanical operating time deviation for estimating future switching instants.

Method and device for monitoring operation of a switching device for controlled switching applications

A method for phase controlled energizing of a power transformer includes acquiring electrical voltage signal from a voltage sensing device connected to the power transformer. Determining a first characterizing data in the voltage signal within a pre-determined set of cycles at about an opening operation of a circuit breaker and determining a second characterizing data within the pre-determined set of cycles in the voltage signal subsequent to the opening operation of the circuit breaker. Estimating a level of magnetization of the core of the power transformer based on at least one of second characterizing data, and the first characterizing data and the second characterizing data. Operating the circuit breaker at a determined instant of switching based on the estimated level of magnetization for a phase controlled energizing of the power transformer by the circuit breaker.

Method for phase controlled energizing of power transformer

In aspects, the present invention provides a method for controlled energizing of a transformer () being connected to a first electrical subsystem () through a first circuit breaker (). The method comprises acquiring electrical current waveform in a first phase of the transformer during a closing operation of the first circuit breaker at an instance for switching determined by a controller (), determining a first peak () in the current in the first phase within a first predetermined time window (Tpw), calculating a first correction factor for adjusting the instance for switching in the first phase, and adjusting the instance for switching based on the calculated first correction factor for performing a next controlled energization at the adjusted instance of switching in the first phase.

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Vadodara, India

Urmil Parikh