摘要:
A voltage sensing system includes a sensing system housing, a circuit board positioned with the sensing system housing, and a phase conductor extending through the sensing system housing, the phase conductor to carry a load current. The system also includes a voltage sensor contact, the voltage sensor contact including a first end and a second end, the first end being electrically coupled to the circuit board and the second end being electrically coupled to the phase conductor.
摘要:
A method and a device provide protection for a multi-terminal HVDC grid against faults. The method includes measuring a DC displacement voltage having a polarity and a value, determining if a short circuit fault exists by comparing the DC displacement voltage with a threshold displacement voltage and identifying a fault type based on the polarity and the value of the DC displacement voltage. The disclosed device contains a converter having a positive pole and a negative pole, a DC-switch substation, a DC line connecting the converter and the DC-switch substation and a transient fault detector. The transient fault detector contains a positive voltage sensor sensing a positive transient voltage of the positive pole and a negative voltage sensor sensing a negative transient voltage of the negative pole and a control unit which is adapted to derive a DC displacement voltage from the positive and the negative transient voltages.
摘要:
Die Erfindung sieht die Verwendung eines E/A-Gerätes mit einer Stromflussüberwachungseinheit vor, die den Stromfluss in Bezug auf zweipolige Peripherieanschlüsse des E/A-Gerätes überwacht und hierauf basierend eine fehlerhafte Installation zwischen der Spannungsversorgung und wenigstens einem an dem wenigstens einem zweipoligen Peripherieanschluss angeschlossenen Aktor oder Sensor diagnostiziert.
摘要:
The invention relates to a method and to device for measuring electric residual currents, which comprise both an alternating current component and a direct current component, by means of an inductive residual current transformer. The known methods for measuring mixed residual currents require special current transformer designs with respect to the coil winding, the magnetic core material and the number of cores. The new method uses the same current transformers that are customary for measuring purely residual alternating currents. According to the invention, the secondary coil (3) of the current transformer is controlled in such a way that the magnetic flux (Φ) linked to the secondary coil (3) in the core remains constant independent of the residual current and the secondary current (Is) required therefor is measured. For this purpose, the ohmic resistance (Rcu) of the secondary coil (3) in the secondary current circuit (4) is compensated by an electronically formed negative resistance (Rz) and a defined magnetic flux is cyclically restored by using the saturation flux (Φs) of the core as reference point.
摘要:
The invention relates to an error recognition device for detecting an error in an electrical component (1), comprising a first detector (12), a second detector (13) for detecting a parameter characteristic of current flows, and a triggering unit (10) for interrupting a current flow through the electrical component (1) by means of a switch (S2), depending on the parameters characteristic of the detected current flows.
摘要:
A DC electrical current busbar associated with electrical load circuits and devices as well as sources requires protection. In order to provide such protection Kirchoff's laws are utilised such that electrical current values are substantially simultaneously taken and summed in order to identify deviations from expected differential threshold values. Upon detection of such deviations and generally as a result of a number of successive deviations an electrical isolation device is utilised in order to isolate electrical current to the busbar. The data set of electrical current values can be utilised in order to provide a back up protection system for individual electrical load devices and circuits, by similar comparison with expected values for those devices and circuits.
摘要:
Resettable circuit interrupting devices (10) having a reset lockout and an optional independent trip mechanism (50, 52, 54) are provided. The reset lockout prevents the resetting of the circuit breaker if the fault protection is non-operational or if an open neutral condition exists, and the trip mechanism operates independently of the fault protection operations.