Switch parallel capacity expansion operation control method based on single-pole contactor

Abstract

The invention provides a switch parallel capacity expansion operation control method based on a single-pole contactor. A two-phase intelligent electromagnetic switch which operates in a parallel modeis included. The electromagnetic switch comprises an intelligent control module and two single-pole contactors; the intelligent control module comprises a synchronous control module, a contact state monitoring module, a coil current controller, a contact sampling circuit and a coil voltage sampling circuit; the contact state monitoring module judges a contact working condition; when switching-on is needed, the synchronous control module enables the switch to be switched on under the working condition of synchronous phasing; when switching-off is needed, the synchronous control module enables the switches to coordinate with each other and to be switched off under the working condition of synchronous zero current. According to the invention, a normal coil current adaptive control mode and anabnormal coil current adaptive control mode are designed, so the stable holding of the two switches during parallel capacity expansion operation is realized; the closed-loop control is performed in the whole process of parallel operation of the two-phase switches, so the synchronism of switching-on and switching-off actions of the switches and adaptive control of the holding process are realized;the switch capacity can be effectively improved, and the application range is widened.

Description

technical field [0001] The invention relates to the technical field of electric power facilities, in particular to a method for controlling the parallel expansion operation of switches based on a single-pole contactor. Background technique [0002] With the continuous development of the national economy, the growth of industrial and residential electricity loads drives the continuous expansion of the power grid. Through self-expansion and Internet interconnection of the power system, the system structure tends to become more complex, and the load is increasing. Under normal circumstances The passing current increases accordingly, and at the same time, the frequency of short-circuit faults and the value of short-circuit fault current also increase. Due to the bottleneck problem of the contact material and contact structure of the contactor, it is difficult to break through, and the rated The current capacity and breaking capacity are difficult to meet the increasing demand fo...

AI Technical Summary

Problems solved by technology

The contact system adopts the form of parallel connection of three-pole dynamic and static contacts to realize capacity expansion. Schneider LC1 series large-capacity AC contactor products are connected in parallel with double coils to increase the electromagnetic suction force during the pull-in process, and the coils are switched to Connect in series to reduce the holding power consumption, and the contact system uses terminals to connect in parallel to expand the capacity. Parallel connection of contacts at the terminals will easily cause a large difference in resistance at both ends of the two-phase contacts, resulting in uneven current distribution.

[0005] None of the existing contactors and products on the market that operate in parallel and expand capacity can effectively control the synchronization of on-off operations, relying on the contact mechanism and parallel connection form of the contactor itself, which is easily affected by mechanism wear and dispersion

For electromagnetic switches that are frequently operated, it is particularly important to ensure the synchronization of opening and closing actions during the whole process of parallel operation of two-phase switches. The two unipolar contactors have independent electromagnetic systems and contact systems, which are convenient for phase separation. At the same time of the control, the dispersion of the contact mechanism and the difference in action characteristics are brought, so it brings certain difficulties to the synchronous control of the opening and closing actions.

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