CN201956852U

CN201956852U - Double speed motor with low starting current

Info

Publication number: CN201956852U
Application number: CN2011200139726U
Authority: CN
Inventors: 张�成; 吕文杰
Original assignee: SHANDONG LIJIU ELECTRICAL MACHINERY CO Ltd
Current assignee: SHANDONG LIJIU ELECTRICAL MACHINERY CO Ltd
Priority date: 2011-01-10
Filing date: 2011-01-10
Publication date: 2011-08-31
Anticipated expiration: 2021-01-10

Abstract

The utility model relates to a double speed motor with low starting current which is characterized by comprising six coils, namely, a coil U Delta, a coil V Delta, a coil W Delta, a coil UY, a coil VY and a coil WY, six wires are adopted for respectively connecting the outer ends of the Delta coils and the Y-shaped coils, wherein the coil U Delta, the coil V Delta and the coil W Delta are always connected into a triangular three phase coil assembly. When in low gear, the wire at the outer end of the coil Y is accessed, the three phases of the coil UY, the coil VY and the coil WY are symmetrical and connected with the coil U Delta, the coil V Delta and the coil W Delta to form a serial subcircuit so as to form a Y-Delta connecting way, when in high gear, the wire at the outer end of the coil Detal is accessed, the current in the coil UY, the coil VY and the coil WY are in opposite directions so as to form a coil in an opposite phase to be respectively connected with the coil U Delta, the coil V Delta and the coil W Delta to form two parallelly connected subcircuits and form two Delta connecting ways. When the double speed motor with low starting current is started with a low speed, the current is small, the torque is high, after stable rotation, the motor does not need to cut off the three phases of power, and is directly switched to a high gear, so that the motor can speed up stably and avoid overlarge impact of current, and the effect on other electric equipment of power grid is reduced.

Description

A kind of low starting current two-speed motor

Technical field

The utility model relates to a kind of motor, a kind of specifically low starting current two-speed motor.

Background technology

The squirrel-cage threephase asynchronous is simple in structure, reliable, easy to maintenance, but its starting current is 6～7 times of rated current when directly starting, excessive starting current can produce very big voltage drop, influence the normal operation of other power consumption equipment on the electrical network, simultaneously the plant machinery parts are caused great impact, generally more powerful motor is taked to reduce the measure of voltage starting with limiting starting current.

Usually the measure of squirrel-cage threephase asynchronous reduction starting current has following measure: (1) stator crosstalk resistance starts, and locked rotor current is bigger, and locked-rotor torque is less, consumes more electric energy in the stall process simultaneously.(2) star---triangle conversion decompression starts, and advantage is that locked rotor current is less, and its starting current is 1/3 of directly startup, and with low cost, shortcoming is that locked-rotor torque is less, can only be used for unloaded and the very light occasion of load.(3) extend-triangle starts, and a part connects star-likely during startup, and a part connects triangular form, and stator winding has centre tap, must propose the tapping ratio requirement to producer, does special order, is not used widely.(4) 3-phase autotransformer reduced-voltage starting, starting resistor is adjustable, and startability is good, and shortcoming is the cost height, and volume is big, safeguards complicated.(5) soft initiator reduced-voltage starting, advantage are that starting resistor is adjustable, and startability is good, but cost an arm and a leg, and are unfavorable for promoting.(6) frequency converter frequency conversion soft start can realize that the low speed low current starts, and the compensated torque function is arranged during startup, and startability is good, and shortcoming is that price is higher, has limited application.

Summary of the invention

Technical problem to be solved in the utility model is in order to overcome the deficiencies in the prior art, and when providing a kind of bottom gear to start, power is little, starting current is little, less to the impact of plant equipment part, operational reliability reduces the low starting current two-speed motor to other power consumption equipment influence of electrical network.

The technical scheme in the invention for solving the above technical problem is: a kind of low starting current two-speed motor, it is characterized in that: be provided with 6 coil U △, V △, W △ and UY, VY, WY, adopt 6 lead-out wires to connect △ coil outer end and Y shape coil outer end respectively, wherein U △, V △, W △ are connected into leg-of-mutton three-phase coil group all the time.Under bottom gear, connect the lead-out wire of Y coil outer end, UY, VY, WY three symmetrically were connected into series arm with U △, V △, W △ and formed the Y-delta connection this moment; Under top gear, connect △ coil outer end lead-out wire, UY, VY, WY current reversal formed reversed phase coil and were connected into two parallel branches with U △, V △, W △ respectively and form 2 delta connections this moment.

The utility model low starting current two-speed motor adopts above-mentioned technology, with groove electromotive force star graph is that the basis is when making the bottom gear pole-changing switch to top gear, need not cut off three phase mains can realize that raising speed is steady and avoid excessive rush of current, each coil of this winding has identical wire gauge, the number of turn, span, be middlebrow two layer winding, very convenient on producing.Against existing technologies, the utlity model has the motor raising speed steadily and avoid excessive rush of current, reduce influence to other power consumption equipment on the electrical network, need not add the step-down converter plant, reduce equipment investment, plant equipment is impacted characteristics such as little, be specially adapted to the various heavy load startings that need simultaneously to the conditional occasion of starting current.

Description of drawings

Fig. 1 is the utility model bottom gear winding construction schematic diagram;

Fig. 2 is the utility model top gear winding construction schematic diagram;

Fig. 3 is the high low speed conversion of a utility model schematic diagram.

Be labeled as among Fig. 1, Fig. 2, Fig. 3: 1., 2., 3., 4., 5., 6. be the power outlet connectivity port.

Embodiment

Below in conjunction with accompanying drawing the utility model is further described:

As shown in Figure 1, a kind of low starting current two-speed motor, have 6 coil U △, V △, W △ and UY, VY, WY, wherein be connected into leg-of-mutton three-phase coil group U △, V △, W △ are symmetrical at top gear and bottom gear equal three, the coil groups UY under the star connection, VY, WY three symmetrical and U △, V △, W △ under bottom gear are connected into series arm and form the Y-delta connection.

As shown in Figure 2.A kind of low starting current two-speed motor, have 6 coil groups U △, V △, W △ and UY, VY, WY, wherein be connected into leg-of-mutton three-phase coil group U △, V △, W △ are symmetrical at top gear and bottom gear equal three, coil groups UY under the star connection, VY, WY are under top gear, UY, VY, WY current reversal, the formation reversed phase coil is connected into two parallel branches with U △, V △, W △ respectively and forms 2 delta connections.

The utility model operational mode: for example 4 utmost points/10 utmost points, 6 utmost points/16 utmost points, 8 utmost points/14 utmost points.Fig. 3 is an example with 6 utmost points/16 utmost point connections, as shown in Figure 3, during startup, leading-out terminal U, V, the W energising, switch S 1 is closed a floodgate, and lead-out wire is 1., 2., 3. energising, this moment, winding was connected into bottom gear, the small-power running, starting current is very little, is approximately about 30% of high power starting current, and detent torque numerical value approaches the high power detent torque, the gentle startup of motor after bottom gear runs well, is closed a floodgate switch S 2, lead-out wire 4., 5., 6. energising, this moment coil groups UY, VY, the WY current reversal forms reversed phase coil and U △, V △, W △ is connected into two parallel branches and forms 2 delta connections, and this moment, high power ran well.

The double speed distal pole of the utility model low starting current compares threephase asynchronous, motor adopts 6 lead-out wires, and the bottom gear locked-rotor torque is near the top gear locked-rotor torque, rotating speed was very low when bottom gear started, start gentle, impact less to the plant equipment part, pole-changing switches to top gear and need not cut off three phase mains and can make raising speed steadily and avoid excessive rush of current, thereby raising operational reliability, minimizing is to the influence of other power consumption equipment of electrical network, can reach the effect of soft start and need not increase step-down equipment.

The utlity model has and to make the motor raising speed steadily and avoid excessive rush of current, reduce influence to other power consumption equipment on the electrical network, need not add the step-down converter plant, reduce equipment investment, plant equipment is impacted characteristics such as little, be specially adapted to the various heavy load startings that need simultaneously to the conditional occasion of starting current.

Claims

1. low starting current two-speed motor, it is characterized in that: be provided with 6 coil groups U △, V △, W △ and UY, VY, WY, adopt 6 lead-out wires to connect △ coil outer end and Y shape coil outer end respectively, U △ wherein, V △, W △ is connected into leg-of-mutton three-phase coil group all the time, under bottom gear, connect the lead-out wire of Y coil outer end, this moment UY, VY, WY three symmetrical and U △, V △, W △ is connected into series arm and forms the Y-delta connection, under top gear, connect △ coil outer end lead-out wire, this moment UY, VY, the WY current reversal, form reversed phase coil respectively with U △, V △, W △ is connected into two parallel branches and forms 2 delta connections.