An electromechanical relay switching system for reducing electromagnetic or radio interference. The system includes an electromechanical relay with an energizeable coil and a microcontroller configured to synchronize energizing the coil relative to a voltage zero crossing time based on a relay contact close time and relay contact bounce time measured particularly for the relay.

In aspects, the present invention discloses a method of determining an electrical operating time of a circuit breaker (140) in a multiphase electrical system having a subsystem (160) connectable to a power source (110) through a circuit breaker (140) operated by a controller (130). The controller is connected to a current transformer (120, 150) for measuring current of the subsystem in a one phase. The method comprises monitoring the current of the subsystem in the one phase, determining a first rate of change from the monitored current in the one phase, detecting an instance of switching in an another phase based on the first rate of change, and determining an electrical operating time of the circuit breaker in the another phase based on the detected instance of switching and an instance at which a command for switching in the another phase was provided to the circuit breaker.

The present invention provides a method of determining an electrical operating time of a circuit breaker (140) in a multiphase electrical system having a subsystem (160) at an electric potential resulting from electrical characteristics of electrical components within the subsystem. The method comprises monitoring (145) the voltage of the subsystem in the first phase, determining a first rate of change from the monitored voltage in the first phase, detecting at least one instance of switching based on the first rate of change, determining an electrical operating time of the circuit breaker based on the detected at least one instance of switching and an instance at which a command for switching was provided to the circuit breaker.

An intelligent electronic device (IED) may provide point on wave switching. The IED may receive a control operation request, and determine when to issue a control command to cause a switch to change positions. The actuation of the switch may occur at a target point on an alternating current. An IED may have a processor that is too slow to implement a switch when a desired point on an alternating current first occurs. Accordingly, some embodiments may compensate for the processing speed of an IED by determining a number of processor cycles needed (in advance) to issue a control command so that the resulting action results in the desired point on wave open or close.

An intelligent electronic device (IED) may provide point on wave switching. The IED may receive a control operation request, and determine when to issue a control command to cause a switch to change positions. The actuation of the switch may occur at a target point on an alternating current. An IED may have a processor that is too slow to implement a switch when a desired point on an alternating current first occurs. Accordingly, some embodiments may compensate for the processing speed of an IED by determining a number of processor cycles needed (in advance) to issue a control command so that the resulting action results in the desired point on wave open or close.

An actuator for a medium voltage circuit breaker or recloser includes: at least one movable contact with a contact stem, driven by an electromagnetic drive or a motor drive; and a spring, the spring being positioned in a kinematic chain between the drive and the at least one movable contact or contact stem. An arrangement of the at least one movable contact and the electromagnetic drive or motor drive is coupled to a detection unit for detecting a micromotion activation in order to register an actual movability and availability of the electromagnetic drive or motor drive of the at least one movable contact without changing an actual switch position itself.

A control and monitoring module is provided for activating an actuator assigned to the control and monitoring module and for monitoring a signal line and/or a power supply line connected to the control and monitoring module and/or to the actuator. The control and monitoring module is configured to detect a fault in the signal line and/or the power supply line, if, during a simulation executed by a testing device, an actual voltage at the control and monitoring module and/or the actuator exceeds a specified upper voltage threshold value or drops below a specified lower voltage threshold value. A system including the control and monitoring module and a method for operating a control and monitoring module are also provided.

An electromechanical relay switching system for reducing electromagnetic or radio interference. The system includes an electromechanical relay with an energizeable coil and a microcontroller configured to synchronize energizing the coil relative to a voltage zero crossing time based on a relay contact close time and relay contact bounce time measured particularly for the relay.

A method of performing a circuit opening and closing operation in a power system including three phases, a three-phase transformer, and a circuit breaker system, the method including a) opening all three phases simultaneously such that a reference current of a reference phase is interrupted first at a first current zero crossing after the opening; and b) closing all three phases simultaneously at a phase to ground voltage of the phase lagging the reference phase by 120?, in a time range of ?90? from a negative peak of said phase to ground voltage if the current zero crossing is a positive current zero crossing, or in a time range of ?90? from a positive peak of said phase to ground voltage if the current zero crossing is a negative current zero crossing.

Methods, devices, and systems for synchronizing switching times of relays to a zero-crossing are described herein. One device includes a memory, and a processor configured to execute executable instructions stored in the memory to receive phase information of an alternating-current (AC) electric mains, determine, from the phase information, a zero-crossing of the phase of the AC electric mains, determine a reference time based on the zero-crossing for a number of relays corresponding to a number of relay controllers, and transmit the reference time to the number of relay controllers.