Arc extinguishing control method of switch

Abstract

The invention provides an arc extinguishing control method of a switch. The control method comprises the steps of acquiring a current I1 of a relay, and processing the current I1 by an MCU; outputtinga signal to disconnect the relay when the current I1 is detected to be at a zero point by the MCU, simultaneously detecting a current I2 when the relay is disconnected, substituting the I2 into a mains supply current formula, and performing calculation to obtain action delay Td1 of the relay; and disconnecting the relay after delay for (T / 2-Td1) seconds when the current I1 is detected to be at the zero point for a second time, detecting a current I3 again when the relay is disconnected, circularly executing the third step until the current is detected to be zero when the relay is disconnected. By extinguishing method, the operation delay of the relay is mastered by a mode of closed-loop feedback and self-learning, and the relay is arranged right at a current zero point position when disconnected to prevent an arc pulling phenomenon.

Description

technical field [0001] The invention relates to the field of electrical equipment, in particular to a switch arc suppression control method. Background technique [0002] Because there is an inductive load in the control circuit, because the current of the inductance will not change suddenly, the moment the relay is disconnected, the electromagnetic energy needs to rely on the breakpoint to generate self-inductance high voltage to break down and maintain the current, thereby generating an arc, which releases energy through the heat of the arc, self-inductance The magnitude of the high voltage generated is determined by the rate of change of the magnetic field. The greater the energy of the load, the greater the arc generated, which will cause permanent damage to the contact surface of the relay due to high temperature melting. The arc suppression device is to eliminate this phenomenon and improve the electrical performance and life of the relay. An existing The first soluti...

AI Technical Summary

Problems solved by technology

In the case of AC, the connection between the load and the power supply is controlled at the zero crossing point. The advantage of this method is that the effect is good and there is no arcing phenomenon. The disadvantage is that the non-contact switch is composed of thyristors inside. The larger the current, the higher the requirements for the thyristors. also bigger

The price is expensive, resulting in complex circuit control, large volume, and high cost. After the thyristor breaks down, it is mostly in a short circuit state, which will cause equipment damage and dangerous accidents

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