CN201976056U

CN201976056U - Same-phase switching circuit of rare earth permanent magnet synchronic motor

Info

Publication number: CN201976056U
Application number: CN201020600253XU
Authority: CN
Inventors: 朱长洪
Original assignee: WUXI JINGWEI TEXTILE SCIENCE AND TECHNOLOGY TEST Co Ltd
Current assignee: WUXI JINGWEI TEXTILE SCIENCE AND TECHNOLOGY TEST Co Ltd
Priority date: 2010-11-10
Filing date: 2010-11-10
Publication date: 2011-09-14
Anticipated expiration: 2020-11-10

Abstract

The utility model discloses same-phase switching circuit of a rare earth permanent magnet synchronic motor, which comprises a power network, a motor M, a first AC contactor KM1, a second AC contactor KM2, a third AC contactor KM3, a frequency converter U1, and a phase detection panel A 1. The same-phase switching circuit of the rare earth permanent magnet synchronic motor provided by the utility model can overcome the defects of poor security and stability, high investment cost and the like in the prior art, and has the advantages of excellent security and stability, low investment cost, and short period of investment return.

Description

A kind of same-phase commutation circuit of rare earth permanent-magnet synchronization motor

Technical field

The utility model relates to rare earth permanent-magnet synchronization motor, particularly, relates to a kind of same-phase commutation circuit of rare earth permanent-magnet synchronization motor.

Background technology

At present; the application of rare earth permanent-magnet synchronization motor and popularization nearly ten years; volume is little because rare-earth permanent-magnet synchronous motor has, loss is low and the efficient advantages of higher; in today that energy savings and environmental protection come into one's own day by day, rare-earth permanent-magnet synchronous motor must be widely used in the every field of national economy.

Along with being gradually improved of converter technique, realize electromechanical integration, its advantage is more and more obvious.But, again because rare-earth permanent-magnet synchronous motor starting torque and overload capacity all exceed a power grade than threephase asynchronous, maximum starting torque can reach 3.6 times with the ratio of rated moment, and general asynchronous motor only has 1.6 times, directly start bigger to the impulsive force of equipment, so rare-earth permanent-magnet electric machine can't directly be applied on some equipment that do not need speed governing, especially heavy-duty motor.

In order to solve this difficult problem, generally adopt the frequency converter soft start in the past, frequency converter withdrawed from after frequency arrived 50HZ, and motor adopts power frequency 50HZ operation.But, there is following shortcoming in control like this: the moment that frequency conversion and power frequency are switched, because phase place and the electrical network phase place of permagnetic synchronous motor when frequency converter withdraws from is inconsistent, cause very big three-phase current, to motor windings, rotor magnetic steel still is that electrical network all forms heavy current impact, even tripping operation.

Particularly, as shown in Figure 1, when motor M starts, the first A.C. contactor KM1 and the second A.C. contactor KM2 adhesive, frequency converter U1 operation, motor begins low rate start until 50HZ, behind the arrival 50HZ, the first A.C. contactor KM1 and the second A.C. contactor KM2 discharge, the 3rd A.C. contactor KM3 adhesive, motor M transfer power frequency 50HZ operation to, and frequency converter U1 stops.In Fig. 1, motor M is a rare earth permanent-magnet synchronization motor.

In addition, in above-mentioned control model, every equipment is in order to use rare earth permanent-magnet synchronization motor, all must increase a frequency converter, just short time work when starting of frequency converter, switch to power frequency operation after, frequency converter is in idle state again, causes the increase and the wasting of resources of cost of investment.

In sum, in realizing process of the present utility model, the inventor finds to exist at least in the prior art following defective:

(1) safety and poor stability: the moment that frequency conversion and power frequency are switched, because phase place and the electrical network phase place of permagnetic synchronous motor when frequency converter withdraws from is inconsistent, causing very big three-phase current, still is that electrical network all forms heavy current impact to motor windings, rotor magnetic steel, even tripping operation;

(2) cost of investment height: every equipment is in order to use rare earth permanent-magnet synchronization motor, all must increase a frequency converter, just short time work when starting of frequency converter, switch to power frequency operation after, frequency converter is in idle state again, causes the increase and the wasting of resources of cost of investment.

Summary of the invention

First purpose of the present utility model is, at the problems referred to above, proposes a kind of same-phase commutation circuit of rare earth permanent-magnet synchronization motor, to realize the advantage of safety and good stability.

For achieving the above object, the technical solution adopted in the utility model is: a kind of same-phase commutation circuit of rare earth permanent-magnet synchronization motor, comprise electrical network, motor M, first to the three A.C. contactor KM1-KM3, frequency converter U1 and phase-detection plate A1, wherein: the described first A.C. contactor KM1, frequency converter U1 and the second A.C. contactor KM2 are connected between electrical network and the motor M successively; Described the 3rd A.C. contactor KM3 is connected in parallel between the common port of the common port of the first A.C. contactor KM1 and electrical network and second A.C. contactor and motor M; Input and the output of described phase-detection plate A1 are connected in parallel on the two ends of the second A.C. contactor KM2; Power end is connected with the 24V DC power supply; Control end is connected with allowing the switching signal end.

Further, described phase-detection plate A1 comprises first sampling unit, power supply, second sampling unit, comparing unit and relay output unit, wherein: the input of described first sampling unit is connected with the output of frequency converter U1, and output is connected with the first input end of comparing unit; The input of second sampling unit is connected with the electrical network input, and output is connected with second input of comparing unit; The power end of described comparing unit is connected with power supply, and output is connected with the input of relay output unit; The output of relay output unit is the control end of phase-detection plate A1.

Further, described electrical network, frequency converter U1 and motor M all meet protection ground PE.

The same-phase commutation circuit of the rare earth permanent-magnet synchronization motor of each embodiment of the utility model, owing to comprise electrical network, motor M, first to the three A.C. contactor KM1-KM3, frequency converter U1 and phase-detection plate A1, wherein: the first A.C. contactor KM1, frequency converter U1 and the second A.C. contactor KM2 are connected between electrical network and the motor M successively; The 3rd A.C. contactor KM3 is connected in parallel between the common port of the common port of the first A.C. contactor KM1 and electrical network and second A.C. contactor and motor M; Input and the output of phase-detection plate A1 are connected in parallel on the two ends of the second A.C. contactor KM2; Power end is connected with the 24V DC power supply; Control end is connected with allowing the switching signal end; Can utilize the characteristics of frequency converter PWM modulated sinusoid, output of monitoring frequency converter and power frequency are imported three alternate magnitudes of voltage, change between 80V-400V according to the voltage of measuring between the two, judge when the voltage between both homophases by sampling unit and comparing unit and to switch during less than 100V, switch current at this time is very little, the impulse current of the different generations of phase place when switching with power frequency with the solution frequency conversion; Thereby can overcome the defective of safety and poor stability in the prior art, to realize the advantage of safety and good stability.

Other features and advantages of the utility model will be set forth in the following description, and, partly from specification, become apparent, perhaps understand by implementing the utility model.The purpose of this utility model and other advantages can realize and obtain by specifically noted structure in the specification of being write, claims and accompanying drawing.

Below by drawings and Examples, the technical solution of the utility model is described in further detail.

Description of drawings

Accompanying drawing is used to provide further understanding of the present utility model, and constitutes the part of specification, is used from explanation the utility model with embodiment one of the present utility model, does not constitute restriction of the present utility model.In the accompanying drawings:

Fig. 1 is the electrical principle schematic diagram of the same-phase commutation circuit of prior art middle rare earth permagnetic synchronous motor;

Fig. 2 is the electrical principle schematic diagram according to the same-phase commutation circuit of the utility model rare earth permanent-magnet synchronization motor;

Fig. 3 is the operation principle schematic diagram according to phase-detection plate in the same-phase commutation circuit of the utility model rare earth permanent-magnet synchronization motor.

In conjunction with the accompanying drawings, Reference numeral is as follows among the utility model embodiment:

1-first sampling unit; The 2-power supply; 3-second sampling unit; The 4-comparing unit; 5-relay output unit.

Embodiment

Below in conjunction with accompanying drawing preferred embodiment of the present utility model is described, should be appreciated that preferred embodiment described herein only is used for description and interpretation the utility model, and be not used in qualification the utility model.

According to the utility model embodiment, as shown in Figures 2 and 3, provide a kind of same-phase commutation circuit of rare earth permanent-magnet synchronization motor.

As shown in Figure 2, present embodiment comprises electrical network, motor M, first to the three A.C. contactor KM1-KM3, frequency converter U1 and phase-detection plate A1, wherein: the first A.C. contactor KM1, frequency converter U1 and the second A.C. contactor KM2 are connected between electrical network and the motor M successively; The 3rd A.C. contactor KM3 is connected in parallel between the common port of the common port of the first A.C. contactor KM1 and electrical network and second A.C. contactor and motor M; Input and the output of phase-detection plate A1 are connected in parallel on the two ends of the second A.C. contactor KM2; Power end is connected with the 24V DC power supply; Control end is connected with allowing the switching signal end.Here, described electrical network, frequency converter U1 and motor M all meet protection ground PE.In Fig. 2, two inputs of phase-detection plate A1 are for allowing the switching signal input, and motor M is a rare earth permanent-magnet synchronization motor.

Further, in the above-described embodiments, as shown in Figure 3, phase-detection plate A1 comprises first sampling unit 1, power supply 2, second sampling unit 3, comparing unit 4 and single 5 yuan of relay output, wherein: the input of first sampling unit 1 is connected with the output of frequency converter U1, and output is connected with the first input end of comparing unit 4; The input of second sampling unit 3 is connected with the electrical network input, and output is connected with second input of comparing unit 4; The power end of comparing unit 4 is connected with power supply, and output is connected with the input of relay output unit 5; The output of relay output unit 5 is the control end of phase-detection plate A1.In Fig. 3, U, V, W are inverter output terminal, and L1, L2, L3 are the electrical network input.

The same-phase commutation circuit of the rare earth permanent-magnet synchronization motor of the foregoing description, when motor M starts, the first A.C. contactor KM1 and the second A.C. contactor KM2 adhesive, frequency converter U1 operation, motor M begins low rate start until 50HZ; After arriving 50HZ, phase-detection plate A1 begins to monitor each corresponding alternate magnitude of voltage, when three-phase voltage between phases value during all less than 100V, output relay (being relay output unit 5) adhesive, the first A.C. contactor KM1 and the second A.C. contactor KM2 discharge, the 3rd A.C. contactor KM3 adhesive, motor M transfer power frequency 50HZ operation to, and frequency converter U1 stops.

As seen, the same-phase commutation circuit of the rare earth permanent-magnet synchronization motor of the foregoing description, owing to comprise electrical network, motor M, first to the three A.C. contactor KM1-KM3, frequency converter U1 and phase-detection plate A1, wherein: the first A.C. contactor KM1, frequency converter U1 and the second A.C. contactor KM2 are connected between electrical network and the motor M successively; The 3rd A.C. contactor KM3 is connected in parallel between the common port of the common port of the first A.C. contactor KM1 and electrical network and second A.C. contactor and motor M; Input and the output of phase-detection plate A1 are connected in parallel on the two ends of the second A.C. contactor KM2; Power end is connected with the 24V DC power supply; Control end is connected with allowing the switching signal end; Can utilize the characteristics of frequency converter PWM modulated sinusoid, output of monitoring frequency converter and power frequency are imported three alternate magnitudes of voltage, change between 80V-400V according to the voltage of measuring between the two, judge when the voltage between both homophases by sampling unit and comparing unit and to switch during less than 100V, switch current at this time is very little, the impulse current of the different generations of phase place when switching with power frequency with the solution frequency conversion; Thereby can overcome the defective of safety and poor stability in the prior art, to realize the advantage of safety and good stability.

In sum, the same-phase commutation circuit of the rare earth permanent-magnet synchronization motor of each embodiment of the utility model is owing to comprise electrical network, motor M, first to the three A.C. contactor KM1-KM3, frequency converter U1 and phase-detection plate A1; By increasing the phase-detection plate, can realize frequency conversion, the little current switching of power frequency, avoid equipment and electrical network are produced impact.

It should be noted that at last: the above only is preferred embodiment of the present utility model, be not limited to the utility model, although the utility model is had been described in detail with reference to previous embodiment, for a person skilled in the art, it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, and perhaps part technical characterictic wherein is equal to replacement.All within spirit of the present utility model and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within the protection range of the present utility model.

Claims

1. the same-phase commutation circuit of a rare earth permanent-magnet synchronization motor is characterized in that, comprises electrical network, motor M, first to the three A.C. contactor KM1-KM3, frequency converter U1 and phase-detection plate A1, wherein:

The described first A.C. contactor KM1, frequency converter U1 and the second A.C. contactor KM2 are connected between electrical network and the motor M successively;

Described the 3rd A.C. contactor KM3 is connected in parallel between the common port of the common port of the first A.C. contactor KM1 and electrical network and second A.C. contactor and motor M;

Input and the output of described phase-detection plate A1 are connected in parallel on the two ends of the second A.C. contactor KM2; Power end is connected with the 24V DC power supply; Control end is connected with allowing the switching signal end.

2. the same-phase commutation circuit of rare earth permanent-magnet synchronization motor according to claim 1 is characterized in that, described phase-detection plate A1 comprises first sampling unit, power supply, second sampling unit, comparing unit and relay output unit, wherein:

The input of described first sampling unit is connected with the output of frequency converter U1, and output is connected with the first input end of comparing unit; The input of second sampling unit is connected with the electrical network input, and output is connected with second input of comparing unit;

The power end of described comparing unit is connected with power supply, and output is connected with the input of relay output unit; The output of relay output unit is the control end of phase-detection plate A1.

3. the same-phase commutation circuit of rare earth permanent-magnet synchronization motor according to claim 1 and 2 is characterized in that, described electrical network, frequency converter U1 and motor M all meet protection ground PE.