Method for keeping pay-off monofilament tension constant in power cable stranding process

The invention discloses a method for keeping pay-off monofilament tension constant in a power cable stranding process. The method comprises the following steps: (1) measuring the distance L2 between the outermost monofilament and the center of a shaft hole of a pay-off reel, wherein the tension generated by the monofilament is F; (2) the distance between the pneumatic clamp and the center of a shaft hole of the pay-off reel is L1, and the friction force generated by the pneumatic clamp and the brake pad is f; (3) according to the lever principle: f * L1 = F * L2, F = f * L1/L2 is obtained; (4) the original friction force generated by the pneumatic clamp and the brake pad is f0, the original tension of the monofilament is F0, the original distance between the monofilament on the outermost layer and the center of the shaft hole of the pay-off reel is L20, and F0 = f0 * L1/L20 can be obtained; (5) after paying off, the friction force generated by the pneumatic clamp and the brake pad is ft, the tension force of