Fault detection method of zero-cross triggering circuit

Abstract

The invention discloses a failure detecting method for the zero-crossing trigger circuit, which comprises the following steps: 11), testing whether the time interval of the zero-crossing signal exceeds the maximum time interval T1 of the zero-crossing signal; if exceeding, then going to the next step; if not exceeding, then going to the step 13); 12), going to the step 14) if the zero-crossing signal circuit works abnormally; 13), if zero-crossing signal circuit works normally, outputting driving signal to the high-power semiconductor device of a main driving loop, and then going back to the step 11); 14), performing failure treatment. Furthermore, the step 11) is as follow: 21), resetting the calculagraph CT and beginning timing; 22), receiving the zero-crossing trigger signal; if existing zero-crossing trigger signal, then going back to the step 21); if not existing zero-crossing trigger signal, then going to the step 23); 23), checking whether the timing time of the calculagraph CT is more than T1; if the timing time of the calculagraph CT is more than T1, then going to the next step; otherwise, going back to the step 22). The invention enables the user to judge whether the failure happens in the zero-crossing trigger circuit accurately.

Description

Technical field [0001] The invention relates to a fault detection method, in particular to a fault detection method of a zero-crossing trigger circuit. Background technique [0002] In the prior art, high-power semiconductor devices such as thyristors and high-power triodes are widely used to control motors or solenoid valves. In the above occasions, the zero-crossing trigger method is often used to control high-power semiconductor devices, that is, at the zero-crossing point of the AC voltage, the high-power electronic devices are controlled to be turned on or off. The zero-crossing trigger circuit is a circuit that controls and detects the zero-crossing point of the alternating current, and outputs a zero-crossing trigger signal accordingly, so as to drive and control the high-power semiconductor. [0003] Due to the zero-crossing trigger method, when the zero-crossing trigger circuit fails, the high-power semiconductor cannot be driven normally, which may cause malfunctions su...

AI Technical Summary

Problems solved by technology

[0003] Due to the zero-crossing trigger method, when the zero-crossing trigger circuit fails, the high-power semiconductor cannot be driven normally, which may lead to failures such as motor out-of-step, solenoid valve action abnormality, etc.

[0004] Under the existing technology, the working condition of the zero-crossing trigger circuit is generally not detected. In this way, when there is a problem with the zero-crossing trigger circuit, it cannot be found in time.

If the fault detection method of directly detecting the working condition of the motor or solenoid valve is used, the specific circuit where the fault occurs will not be known, and the fault of the zero-crossing trigger circuit may be judged as the fault of the main circuit, resulting in misjudgment

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