A kind of detection method of grounding current of polysilicon reduction furnace power supply system

Abstract

The invention discloses a method for detecting the grounding current of a polysilicon reduction furnace power supply system by grades. According to the difference of the constant current maintenance voltage required in different stages of silicon core growth, the maintenance voltage is set in grades, and each grade is set with a corresponding early warning value of the grounding current. and the action value, the warning value is less than the action value. When the ground current corresponding to the maintenance voltage reaches the early warning value, an early warning will be given, and the operator will adjust the process parameters according to the early warning to avoid or delay the ground current reaching the operating value; when the ground current corresponding to the maintenance voltage reaches the operating value, the polysilicon reduction furnace power supply system will be stopped. operation. The protection accuracy of the invention is higher, and while ensuring the safe operation and production of the reduction furnace, phase loss and delayed phase loss can be reduced, and the effective operation time of the reduction furnace is increased, thereby increasing the production capacity.

Description

technical field [0001] The invention relates to the technical field of polysilicon reduction furnaces, in particular to a method for detecting the grounding current of a power system of a polysilicon reduction furnace. Background technique [0002] Since 2005, polysilicon has been gradually promoted in China, and the reduction power used by various polysilicon manufacturers is monopolized by AEG-pre-reduction electrical system technology (for 9 pairs of rods and 12 pairs of rods for polysilicon reduction furnaces). From 2007 to 2009, some domestic reduction power supply manufacturers broke the foreign technology monopoly one after another, and successively invested in new domestic polysilicon projects (for 12, 18, 24, 36, 72 pairs of rod polysilicon reduction furnaces), and for the polysilicon production process. The ground leakage current detection caused by the change of conditions has always used the AEG reduction power supply to detect the ground leakage current value, b...

AI Technical Summary

Problems solved by technology

From 2007 to 2009, some domestic reduction power supply manufacturers successively broke the monopoly of foreign technology and successively invested in new domestic polysilicon projects (for 12, 18, 24, 36, 72 pairs of rod polysilicon reduction furnaces). The ground leakage current detection caused by environmental changes has been using the AEG reduction power supply to detect the ground leakage current value, but it has the problem that the current detection value is fixed and cannot adapt to the adjustment of the production process of the reduction furnace, resulting in frequent phase loss production and wasting a lot of manpower and resources. Material resources

When the operating voltage of the entire operating cycle is reduced from 2650V to the minimum of 520V, the grounding current protection value is fixed at 900mA. When the operating voltage is too low (below 520v), the grounding point cannot be effectively protected. The maximum grounding current value of this point is 600mA. The value is 900mA, which has potential safety hazards; on the contrary, when operating at high voltage (above 1500V), the actual grounding current of 1500mA at this point is far greater than the protection value of 900mA, resulting in early stop operation, resulting in phase-out operation and reducing the output of a single furnace

[0004] In addition, when false grounding or short-term grounding occurs during operation, the operation will be stopped directly, which is not suitable for the actual production process of polysilicon

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