252-slot and 14-pole asymmetric four-branch two-layer three-phase stator winding

Abstract

The invention relates to a stator winding, in particular to a 14-pole and 252-slot asymmetric four-branch two-layer three-phase stator winding. Two layers, namely an upper layer and a lower layer, of wire rods embedded in stator slots are connected at the end parts by a straight end-to-end joint sleeve, an oblique end-to-end joint sleeve and a short copper ring for forming coils in three pitches, by changing winding pitches, and are regularly connected in series for forming four branches, , and the four branches are connected in parallel for forming the stator winding. According to the stator winding disclosed by the invention, the new asymmetric four-branch two-layer three-phase stator winding which does not meet the condition of a symmetric winding is formed by changing the arrangement law and the connection form of the 14-pole and 252-slot winding. The stator winding disclosed by the invention can not only realize excellent performances of a motor, increase voltage grade, increase the number of the slots which can be selected by a stator of the 14-pole motor and greatly upgrade a motor design technology, but also reduce the axial length of the motor, reduce the height of a factory building and save the construction cost of a power station. The stator winding disclosed by the invention is suitable for 14-pole and 252-slot salient pole synchronous motors, in particular for the field of large-scale water-pumping energy storage motors.

Description

technical field [0001] The invention relates to a two-hundred-fifty-two-slot fourteen-pole asymmetrical four-branch double-layer three-phase stator winding. Background technique [0002] The pumped-storage motor frequently operates under the two working conditions of power generation and electric power, and its rotation direction is opposite, usually at a higher speed, so its design technology is unique. And as the capacity gradually increases, the design difficulty becomes more and more difficult. The pumped storage motor with a capacity of 300MW and a speed of 428.6r / min (fourteen poles) is widely used, and the performance of the turbine with this speed is superior. However, the number of symmetrical parallel branches of the stator winding of the fourteen pole motor can only be 1, 2, 7 and 14, and the corresponding rated voltages are 13.8kV and 15.75kV. The length of the branch stator winding is nearly 500 mm, which increases the manufacturing cost of the motor and the c...

AI Technical Summary

Problems solved by technology

However, the number of symmetrical parallel branches of the stator winding of the fourteen pole motor can only be 1, 2, 7 and 14, and the corresponding rated voltages are 13.8kV and 15.75kV. The length of the branch stator winding is nearly 500mm, which increases the manufacturing cost of the motor and the construction cost of the power station

If a four-branch asymmetric winding is used, there will be problems such as unequal potentials of the branches, different phases, and difficult connection of the windings.

The motor with four-branch stator windings has superior performance and low cost, but the windings do not meet the symmetrical conditions and are branch asymmetrical windings

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