摘要:
An apparatus for starting and controlling a motor. The apparatus includes means for monitoring the load current values in each phase of a motor. These means can include an apparatus such as a current transformer. The apparatus utilizes a circuit for modeling a motor and estimating the temperatures of the motor's windings and housing. The circuit preferably is defined by a programmed microprocessor. The estimated temperatures are based on the load current values and time. These estimated temperatures are then compared to allowable limits and, based on the comparison, the motor is either stopped or allowed to run.
摘要:
Déclencheur statique numérique agencé pour une protection contre les défauts de phase, notamment les surcharges et les courts-circuits et des fonctions optionnelles, en l'occurrence la protection de terre et les fonctions de délestage et de relestage. Deux commutateurs (72, 74) d'entrée des paramètres sont affectés aux fonctions optionnelles pour afficher, dans l'option protection de terre le seuil de protection de terre et la temporisation protection de terre et dans l'option délestage, le seuil de relestage et le seuil de délestage. A chaque option correspond un logiciel enregistré dans une mémoire non volatile.
摘要:
Digitaler Überstromauslöser für den Netzschutz mit einem einen nichtpermanenten digitalen Speicher (7) (volatile memory) für den thermischen Anregungszustand und einen Analog-Digital-Konverter umfassenden Mikroprozessor (3, 13), bei dem zwecks Speicherung des thermischen Anregungszustandes beim Auslösen sowie zur Simulierung eines Abkühlvorganges ein zusätzlicher permanenter Speicher sowie ein mit einer bekannten Spannung aufgeladenes RC-Glied (5, 16) vorgesehen sind.
摘要:
A power supply control apparatus includes: a semiconductor switching element (6) configured to be switched with PWM control; a PWM signal output unit (1) configured to output a PWM signal pertaining to the PWM control; a current circuit (5) configured to output a current related to a current flowing through the semiconductor switching element (6); a filter circuit (11 to 13) configured to convert the current that is output from the current circuit (5) to a voltage and to filter the converted voltage; an overcurrent protection circuit (4) configured to turn off the semiconductor switching element (6) based on a voltage value of the voltage filtered by the filter circuit (11); a voltage detection unit(2) configured to detect the voltage value of the voltage filtered by the filter circuit (11 to 13) at a timing near an end of a pulse of a PWM signal; a temperature estimation unit (1) configured to estimate, based on the voltage value detected by the voltage detection unit (2), a temperature of an electric wire through which a current flows that also flows through the semiconductor switching element (6); and an electric wire protection unit (1) configured to turn off the semiconductor switching element (6) based on the temperature estimated by the temperature estimation unit (1).
摘要:
There is disclosed an apparatus and method for protecting an electrical device. The electrical device is coupled to a power source, and an electric load, a sensor, and a controller. The controller is configured to shut off the electrical device if certain sensed thermal values exceed predetermined values.