The basic requirements of the relay protection and safety automatic device of the CNC busbar processing machine are reliability, safety, sensitivity, selectivity, and quick action.

Relay protection is classified into main protection and backup protection.

When the main protection fails, it will first act correctly and reliably, and cut off the fault within the protection range in the shortest time or without time limit.

Numerical control bus processing machines such as differential protection of transformers, high frequency protection of transmission lines, distance protection, zero sequence current protection, etc. Backup protection is the protection that works when the main protection of the protected electrical equipment, transmission line or circuit breaker fails, such as the overcurrent protection of transformers and transmission lines.

Safety automatic devices such as automatic reclosing device of transmission line, automatic input device of auxiliary power backup power supply, automatic input device of substation bus or section bus backup power supply, automatic frequency reduction device, electric brake and automatic cutting device, etc. .

When a short-circuit fault occurs in the power distribution system of the busbar machine, there will be a voltage dip, a sudden rise, or a system asymmetry. This state may cause the interruption of production or other processes and cause huge losses. In order to avoid such incidents, the requirements for power supply quality of power companies have continued to increase, and the power industry is therefore undergoing major changes.

    On the other hand, the single-sided power supply method that we are still using until recently has also changed due to the continuous access of distributed power sources to the power distribution system.

Modern power distribution protection uses comprehensive multi-function devices, designed to meet the needs of all power distribution systems, and provide optimal protection functions for the power distribution system under various system conditions. The application of advanced power distribution protection functions can greatly shorten the fault clearing time.

The insulation material (core insulation and sheath insulation) of the cable is both an insulating material and a heat-insulating material. Therefore, when the power cable is laid in the bridge, a maximum of 2 layers are allowed. The reason is to consider heat dissipation.

The overload capacity of the bus duct of the CNC bus processing machine is strong, which depends on the high working temperature of the insulating material used. The insulating material used for the bus duct of the bus processing machine is over-supported using materials with a working temperature of 105 ℃. It has been developed to work at a temperature of 140 ℃. The above radiation cross-linked flame-retardant winding tape (PER) and radiation cross-linked polycarbonate heat shrinkable tube.

The normal working temperature of the insulating material used in the cable is generally 95°C and 105°C, so the overload capacity of the bus duct is far greater than that of the cable. The busway hardly needs maintenance. Daily maintenance is usually to measure the temperature rise of the shell and the core bolts, the temperature rise of the inlet box joints, etc. If the core bolts are grade 4.8, they need to be tightened regularly, and if grade 8.8 high-strength bolts are used It does not have to be firm regularly.