Method for controlling an electromagnetic contactor and electromagnetic contactor implementing such a method
AssigneeABB Schweiz AG
InventorChristophe Hamond
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Abstract
The present invention relates to a control method for an electromagnetic contactor and an electromagnetic contactor implementing such a method, where the method includes supplying an electromagnet of the contactor with a pulse width modulation supply signal and having a nominal frequency, the method also including varying the period over at least part of the pulses of the modulation so as to reduce the conducted electromagnetic disruptions, the variation of the period being chosen such that the frequency of the supply signal remains comprised in a given frequency band including the nominal frequency.
Claims9
A control method for an electromagnetic contactor, the method comprising:
- supplying an electromagnet of the contactor with a pulse width modulation (PWM) supply signal, the PWM supply signal having a nominal frequency;
- and
- varying the period of the pulses of the PWM supply signal over at least part of the pulses of the PWM supply signal so as to reduce parasites that disrupt operation of electrical and electronic apparatuses positioned near the contactor, the varying of the period of the pulses of the PWM supply signal taking into account a caliber defining an acceptable disruption limit for the parasites that disrupt the operation of the electrical and electronic apparatuses positioned near the contactor, the disruption limit being defined per frequency value in a given frequency band including the nominal frequency, the given frequency band ranging from 150 kHz to 30 MHz,
- wherein the variation of the period is chosen such that a frequency of the supply signal remains comprised in the given frequency band, the variation of the period of the pulses of the PWM supply signal determined randomly.
An electromagnetic contactor including a control circuit configured to perform operations comprising:
- supplying an electromagnet of the contactor with a pulse width modulation (PWM) supply signal, the PWM supply signal having a nominal frequency;
- and
- varying the period of the pulses of the PWM supply signal over at least part of the pulses of the PWM supply signal so as to reduce parasites that disrupt operation of electrical and electronic apparatuses positioned near the contactor, the varying of the period of the pulses of the PWM supply signal taking into account a caliber defining an acceptable disruption limit for the parasites that disrupt the operation of electrical and electronic apparatuses positioned near the contactor, the disruption limit being defined per frequency value in a given frequency band including the nominal frequency, the given frequency band ranging from 150 kHz to 30 MHz,
- wherein the variation of the period is chosen such that a frequency of the supply signal remains comprised in the given frequency band, the variation of the period of the pulses of the PWM supply signal is determined randomly.
Dependencies are inferred from the claim text.