CN103546088B - The revolution speed control device of motor and method for controlling number of revolution - Google Patents

Abstract

The present invention relates to revolution speed control device and the method for controlling number of revolution of a kind of motor, the converter general for market and motor combination, can easily avoid stall of motor state, and make electronic function reach rotating speed of target in relatively short period of time.Wherein, revolution speed control device includes: soft start unit, rotary speed controling unit, interrupt location and Application of Motor Speed Detecting unit.

Description

The revolution speed control device of motor and method for controlling number of revolution

Technical field

Embodiments of the present invention relate to revolution speed control device and the method for controlling number of revolution of a kind of motor.

Background technology

In work mechanism main shaft drives region, by the friendship of transducer drive asynchronous motor (hreinafter referred to as motor) Rheology frequency modulation short-term training is main flow.

Motor, with rated speed as separation, respectively can determine torque zone and rotating speed more than volume at rotating speed less than rated speed The output area of determining determining rotating speed uses.Determining the maximum output torque of output area motor along with the increase of the rotating speed of motor And reduce.Therefore, motor is when determining output area and using, and during motor constantly accelerates, its maximum output turns Square is possibly lower than required load torque and the sum of accelerating torque.The maximum output torque of motor is born less than required Set torque and accelerating torque and time, converter is in order to increase the output torque of motor, and increases its output electric current, now Slippage increases the most therewith.But, the now torque of motor but can not increase therewith, and motor enters stall region.Electricity After motivation enters stall region, if the output electric current of converter increases, slippage can not reduce.If electric current is increasing, Then converter will trip because flowing through overcurrent, and operating stops.

In order to prevent the generation of stall conditions, generally carry out main shaft special converter and the test of each motor combination, in order to Solve the motor output characteristics at regional, and by its parametrization.But, when converter general on market, Such composite test is implementing extremely difficult, therefore, seeks one and can not be combined test, it becomes possible to easily Avoid the stall conditions of motor, but also revolution speed control device and the rotating speed of rotating speed of target can be reached in relatively short period of time Control method.

Summary of the invention

The purpose of embodiments of the present invention is, it is provided that a kind of stall conditions that can easily avoid motor, but also Revolution speed control device and the method for controlling number of revolution of rotating speed of target can be reached in relatively short period of time.

The present invention provides the revolution speed control device of a kind of motor, including: soft start unit, its target receiving motor turns Speed and acceleration time, when this rotating speed of target received of soft start unit is more than the last rotating speed of target received, will This acceleration time is divided into multiple points of acceleration time sections, and the rotating speed of target this received is converted into when accelerating with multiple points Between the respectively corresponding multiple partial objectives for rotating speeds of section, each partial objectives for rotating speed both greater than soft start unit receives this rotating speed of target The partial objectives for rotating speed of moment output, a rear partial objectives for rotating ratio previous partial objectives for rotating speed is big, last partial objectives for rotating speed etc. In this rotating speed of target received, soft start unit exports time period of each partial objectives for rotating speed and each point of acceleration time section Corresponding；Application of Motor Speed Detecting unit, the output speed of its detection motor；Rotary speed controling unit, its output drives electronic Machine rotate the signal of telecommunication, and according to soft start unit output current partial objectives for rotating speed and Application of Motor Speed Detecting unit detection First difference of the output speed of the motor arrived, controls the output speed being sized such that motor of the signal of telecommunication to soft start The current partial objectives for rotating speed of unit output is close, and the current partial objectives for rotating speed that the frequency of the signal of telecommunication exports with soft start unit is relative Should；Interrupt location, the frequency at the signal of telecommunication from rotary speed controling unit and the motor from Application of Motor Speed Detecting unit The second difference of the frequency corresponding to output speed more than or equal to prespecified threshold value time, make the output of soft start unit protect Hold as current partial objectives for rotating speed.

In the revolution speed control device of above-mentioned motor, described soft start unit calculates the subhead of output according to equation below (1) Mark rotating speed, calculate a point acceleration time section according to equation below (2),

$N_{out}\left(k\right)=N_{out}^{\′}+k\frac{N_{in}-N_{out}^{\′}}{n}---\left(1\right)$

$T^{\′}=\frac{T}{n}---\left(2\right)$

Wherein, N'_outBe described soft start unit receive than on during the big rotating speed of target of the rotating speed of target that once receives Carve, the partial objectives for rotating speed of described soft start unit output,

N_inIt is for making motor speed increase this rotating speed of target received of described soft start unit,

N is the acceleration times of regulation, for the positive integer more than 1,

N_outK () represents the partial objectives for rotating speed that described soft start unit divides acceleration time section to export in kth, k is for being more than or equal to The positive integer of 1, the value of k is 1 ... n,

T ' represents each point of acceleration time section,

T represents this acceleration time received of soft start unit.

In the revolution speed control device of above-mentioned motor, described threshold value is set to the multiple of the rated slip of described motor.

In the revolution speed control device of above-mentioned motor, described threshold value is set to 2～4 times of the rated slip of described motor.

In the revolution speed control device of above-mentioned motor, the output speed of described motor and the output electricity of described rotary speed controling unit In the relation of pressure, described motor has the characteristic of regulation, in the characteristic of described regulation, along with the output of described motor turns The output voltage of the described rotary speed controling unit that accelerates of speed also uprises, and the output speed of described motor reaches more than rated speed Time, the output voltage of described rotary speed controling unit is saturated with maximum.

The present invention provides the method for controlling number of revolution of a kind of motor, including: soft start step, its target receiving motor turns Speed and acceleration time, when this rotating speed of target received is more than the last rotating speed of target received, will divide the acceleration time For multiple points of acceleration time sections, the rotating speed of target this received is converted into corresponding the most with multiple points of acceleration time sections Individual partial objectives for rotating speed, each partial objectives for rotating speed both greater than receives the partial objectives for rotating speed of the moment output of this rotating speed of target, after One partial objectives for rotating ratio previous partial objectives for rotating speed is big, and last partial objectives for rotating speed is equal to this rotating speed of target received, defeated The time period going out each partial objectives for rotating speed is corresponding with each point of acceleration time section；Application of Motor Speed Detecting step, detects motor Output speed；Rotating speed rate-determining steps, the signal of telecommunication that its output drive motor rotates, and according to current partial objectives for rotating speed With the first difference of the output speed of motor, control the output speed being sized such that motor of the signal of telecommunication to current subhead Mark rotating speed is close, and the frequency of the signal of telecommunication is corresponding with current partial objectives for rotating speed；Interrupt step, in the frequency of the signal of telecommunication and electronic When second difference of the frequency corresponding to the output speed of machine is more than or equal to prespecified threshold value, the partial objectives for keeping current turns Speed.

In the method for controlling number of revolution of above-mentioned motor, in described soft start step, calculate output according to equation below (1) Partial objectives for rotating speed, calculate a point acceleration time section according to equation below (2),

$N_{out}\left(k\right)=N_{out}^{\′}+k\frac{N_{in}-N_{out}^{\′}}{n}---\left(1\right)$

$T^{\′}=\frac{T}{n}---\left(2\right)$

Wherein, N'_outBe receive than on the partial objectives for of moment output of the big rotating speed of target of the rotating speed of target that once receives Rotating speed,

N_inIt is for making motor speed increase and rotating speed of target that this receives,

N is the acceleration times of regulation, for the positive integer more than 1,

N_outK () represents that k is the positive integer more than or equal to 1, k at the partial objectives for rotating speed that kth divides acceleration time section to export Value be 1 ... n,

T ' represents each point of acceleration time section,

T represents this acceleration time received.

In the method for controlling number of revolution of above-mentioned motor, described threshold value is set to the multiple of the rated slip of described motor.

In the method for controlling number of revolution of above-mentioned motor, described threshold value is set to 2～4 times of the rated slip of described motor. The revolution speed control device of the motor of a mode according to the embodiment of the present invention and method for controlling number of revolution, general for market Converter and motor combination, can easily avoid the stall conditions of motor, and make electronic function when shorter Between reach rotating speed of target.

Accompanying drawing explanation

Fig. 1 (A) illustrates the graph of relation of the rotating speed of main shaft definite-purpose motor and common motor and the output voltage of converter, Fig. 1 (B) illustrates the rotary speed-torque curve chart of main shaft definite-purpose motor and common motor.

Fig. 2 illustrates when employing converter carries out variable frequency regulating speed control, the rotary speed-torque curve chart of motor.

Fig. 3 illustrates the pie graph of the revolution speed control device of the motor of the present invention.

Fig. 4 illustrates the partial objectives for rotating speed that soft start unit increases with equal amplitude in each point of acceleration time section output that length is equal In the case of, the rotating speed of target of soft start unit output and the schematic diagram of the relation of time.

Fig. 5 (A) illustrates motor rotary speed-torque curve chart in the normal state, and Fig. 5 (B) illustrates that motor is in stall Rotary speed-torque curve chart under state.

Fig. 6 illustrates because of by monitoring that slippage detects that stall of motor keeps when currently exporting of soft start unit 11, electric The rotary speed-torque curve chart of motivation.

Fig. 7 is the flow chart of the method for controlling number of revolution of motor.

Detailed description of the invention

In main shaft drives field, typically by transducer drive main shaft definite-purpose motor, and made processed by main shaft definite-purpose motor Thing rotates, and is processed machined object by feeding cutting edge.But, main shaft definite-purpose motor price is higher, therefore, It is considered as common motor to substitute main shaft definite-purpose motor.

Fig. 1 (A) illustrates the graph of relation of the rotating speed of main shaft definite-purpose motor and common motor and the output voltage of converter, Fig. 1 (B) illustrates the rotary speed-torque curve chart of main shaft definite-purpose motor and common motor.As shown in Fig. 1 (A), commonly Motor is when reaching rated speed (such as 1500rpm), and the output voltage of converter just reaches maximum, referred to as electricity Pressure saturation.Owing to output voltage reaches maximum, motor power (output) is also limited, and motor power (output) is maximum Torque and rotating speed long-pending, if motor continues to accelerate, torque capacity have to decline.So common motor is reaching volume After determining rotating speed, maximum output torque is declining (with reference to Fig. 1 (B)) the most always.When maximum output torque drops below Required load torque and accelerating torque and time, motor has been put into stall conditions.Main shaft definite-purpose motor is come Saying, spindle drive motor is when reaching rated speed, and the output voltage of converter is also not reaching to maximum, is exceeding specified turn Certain rotating speed (such as 3000rpm) after speed, the output voltage of converter just reaches maximum, if now motor is still Continuing to accelerate, torque capacity have to decline (with reference to Fig. 1 (B)).As shown in Fig. 1 (B), exceeding rated speed Region, the torque capacity of common motor is consistently lower than the torque capacity of main shaft definite-purpose motor, therefore, special with main shaft Motor is compared, and common motor is more easy to stall.

The revolution speed control device of the present invention and method for controlling number of revolution are mainly used in the common motor being more easy to stall, but right For main shaft special electric electric motor, it is possible to apply revolution speed control device of the present invention and method for controlling number of revolution.Go out herein Existing motor is in addition to special instruction, including common motor and main shaft definite-purpose motor.

Below, Fig. 2 is used as a example by common motor, the situation that stall occurs to be specifically described.Fig. 2 illustrates that employing becomes Frequently when device carries out variable frequency regulating speed control, the rotary speed-torque curve chart of motor.Motor, with rated speed as separation, divides Can not use more than the output area of determining of rated speed less than determine torque zone and the rotating speed of rated speed at rotating speed.Determining output The maximum output torque of region motor reduces along with the increase of the rotating speed of motor.Therefore, output area determined by motor During use, during motor constantly accelerates, its maximum output torque is possibly lower than required load torque and adds The sum of speed torque.The maximum output torque of motor less than required load torque and accelerating torque and time, converter is Increasing the output torque of motor, and increase its output electric current, now slippage increases the most therewith.But, now motor Torque but can not increase therewith, motor enters stall region.After motor enters stall region, converter If output electric current increases, slippage can not reduce.If electric current is increasing, then converter will trip because flowing through overcurrent, fortune Turn and stop.

Revolution speed control device according to embodiment of the present invention and method for controlling number of revolution so that once motor generation stall, i.e. Stop the output frequency change of converter, make the rotating speed of motor catch up with the output frequency change of converter.Turning at motor After speed has caught up with the output frequency change of converter, then increase the output frequency of converter, so that motor accelerates.Hereinafter, Referring to the drawings revolution speed control device and the method for controlling number of revolution of embodiment of the present invention is illustrated.

Fig. 3 illustrates the pie graph of the revolution speed control device of the motor of the present invention.Hereinafter, with reference to electronic to the present invention of Fig. 3 The composition of the revolution speed control device of machine is described in detail.The revolution speed control device 10 of the present invention is arranged on converter (not Diagram) inside, in order to control output voltage and the frequency of converter, thus control the rotating speed of motor 20.Rotating speed control Device 10 processed includes: soft start unit 11, speed discrepancy computing unit 12, rotary speed controling unit 13, interrupt location 14, Slippage computing unit 15 and Application of Motor Speed Detecting unit 16.Revolution speed control device 10 is connected to motor 20, for electricity Motor speed in motivation 20 accelerator controls.

Soft start unit 11, for exporting the rotating speed of target of slowly lifting, makes the overall process of motor start-up the most there is not impact Torque, but smooth startup optimization.Soft start unit 11 can receive rotating speed of target and acceleration time, this rotating speed of target Can be that user is manually entered with the acceleration time.It is more than once at this rotating speed of target received of soft start unit 11 During the rotating speed of target received, i.e. showing that motor 20 need to be accelerated, now, soft start unit 11 is by this acceleration Time is divided into multiple points of acceleration time sections.The rotating speed of target that this is received by soft start unit 11 is converted into and adds with multiple points Multiple partial objectives for rotating speeds that the speed time period is the most corresponding, each partial objectives for rotating speed both greater than soft start unit 11 receives this The partial objectives for rotating speed of the moment output of rotating speed of target.These partial objectives for rotating speeds are corresponding with each point of acceleration time section, soft start The time period that unit 11 exports each partial objectives for rotating speed is corresponding with each point of acceleration time section.Revolution speed control device 10 is sequentially pressed According to each point of acceleration time section, motor 20 is accelerated.Owing to being accelerator, after institute before a partial objectives for rotating ratio One partial objectives for rotating speed is big, and finally makes the partial objectives for rotating speed finally exported equal to this rotating speed of target received.

Below, the partial objectives for increased with equal amplitude in each point of acceleration time section output that length is equal with soft start unit 11 Illustrate in case of rotating speed.In this case, soft start unit 11 calculates output according to equation below (1) Partial objectives for rotating speed.

$N_{out}\left(k\right)=N_{out}^{\′}+k\frac{N_{in}-N_{out}^{\′}}{n}\mathrm{...}\left(1\right)$

A point acceleration time section is calculated according to equation below (2),

$T^{\′}=\frac{T}{n}\mathrm{...}\left(2\right)$

Wherein, N'_outBe described soft start unit 11 receive than on the big rotating speed of target of the rotating speed of target that once receives Moment, the partial objectives for rotating speed of described soft start unit 11 output, if motor 20 is in the steady statue after having accelerated, Then the current rotating speed of motor 20 reaches N'_out。N_inFor making motor 20 rotating speed increase, soft start unit 11 this connect The rotating speed of target received.N is the acceleration times of regulation, for the positive integer more than 1.The numerical value of n is the most pre-set, Certainly, it can also be adjusted by user.N_outK () represents that described soft start unit 11 divides acceleration time section in kth The partial objectives for rotating speed of output, k is the positive integer more than or equal to 1, and the value of k is 1 ... n, T ' represent each point of acceleration time Section.T represents this acceleration time received of soft start unit 11.

Fig. 4 illustrates the partial objectives for that soft start unit 11 increases with equal amplitude in each point of acceleration time section output that length is equal In the case of rotating speed, the rotating speed of target of soft start unit 11 output and the schematic diagram of the relation of time.As shown in Figure 4, soft The rotating speed of target that user is inputted by start unit 11, is converted to the partial objectives for rotating speed being gradually incremented by, makes the complete of motor start-up The most there is not impact torque in process, but smooth startup optimization.

Although the above is to export with dividing that equal amplitude increases in each point of acceleration time section that length is equal with soft start unit 11 Illustrate in case of rotating speed of target, but the present invention be not limited to this, each point of acceleration time section can with length, Each partial objectives for rotating speed can also be non-etc. amplitude increase.

Application of Motor Speed Detecting unit 16, in motor accelerator, detects the actual output speed of motor 20.Electronic Machine rotation speed detection unit 16 can use photoelectric encoder.

Speed discrepancy computing unit 12, calculates current partial objectives for rotating speed and the Application of Motor Speed Detecting list of soft start unit 11 output First value of delta 1 of the actual output speed of the motor 20 that unit 16 detects.

The signal of telecommunication that rotary speed controling unit 13 output drive motor 20 rotates, and according to from speed discrepancy computing unit 12 The first value of delta 1, control the signal of telecommunication size so that the output speed of motor 20 exports to soft start unit 11 Current partial objectives for rotating speed is close.Specifically, when soft start unit 11 exports new partial objectives for rotating speed, owing to being acceleration Process, a rear partial objectives for rotating ratio previous partial objectives for rotating speed is big, the first difference that therefore speed discrepancy computing unit 12 calculates δ 1 increases, and the electric current being controlled converter output by rotary speed controling unit 13 also can be increased, thus strengthens output torque, makes It is close that the rotating speed of motor 20 exports new partial objectives for rotating speed to soft start unit 11.

The current partial objectives for rotating speed that the frequency of the signal of telecommunication of rotary speed controling unit 13 output exports with soft start unit 11 is relative Should.The frequency of the signal of telecommunication of rotary speed controling unit 13 output refers to be controlled the electricity of converter output by rotary speed controling unit 13 The frequency of stream.That is, while the partial objectives for rotating speed in soft start unit 11 output is gradually increased, the electric current of converter output Frequency the most correspondingly become larger.

Slippage computing unit 15, calculates the frequency of the signal of telecommunication from rotary speed controling unit 13 and from Application of Motor Speed Detecting Second value of delta 2 of the frequency corresponding to actual output speed of the motor 20 of unit 16.Slippage computing unit 15 calculates The second value of delta 2 be exactly the slippage of motor 20.Here, slippage is represented by the difference of frequency.Hereinafter, slippage is sometimes Also represent by the difference of synchronous rotational speed with motor actual speed.Slippage is expressed the difference only existing dimension by both modes, Can mutually change.

Fig. 5 (A) illustrates motor 20 rotary speed-torque curve chart in the normal state, wherein, synchronous rotational speed N_s1With electricity Motivation rotating speed N₁Difference be the slippage under current frequency converter frequency.Fig. 5 (B) illustrates that motor 20 is under stall conditions Rotary speed-torque curve chart, wherein, synchronous rotational speed N_s2With motor speed N₂Difference be under current frequency converter frequency Slippage.As shown in Fig. 5 (A), Fig. 5 (B), when motor 20 is changed into stall conditions from usual state, its slippage Become big the most therewith.It practice, along with being gradually increased of partial objectives for rotating speed of soft start unit 11 output, rotary speed controling unit The frequency of the electric currents of 13 outputs also becoming larger (with reference to Fig. 2), determine output area carry out work when motor 20 enter into When making, the increase of the frequency of the electric current that the slippage of the motor 20 under identical torque exports also with converter and be gradually increased, When motor 20 is stall conditions, it is bigger that slippage just becomes.Advise in the change determining output area according to above-mentioned slippage By monitoring the sliding extent of slippage computing unit 15 output, rule, can judge whether motor 20 enters into stall shape State.

Interrupt location 14, when being more than or equal to prespecified threshold value Th from the second value of delta 2 of slippage computing unit 15, The output making soft start unit 11 remains current partial objectives for rotating speed, namely makes soft start unit 11 temporarily no longer export Next higher partial objectives for rotating speed.Fig. 6 illustrates because of by monitoring that slippage detects that stall of motor keeps soft start unit 11 when currently exporting, the rotary speed-torque curve chart of motor.As shown in Figure 6, it is converted to curve L when converter₁Time, The torque capacity of motor 20 is less than load torque and the sum of accelerating torque, motor 20 stall.Now detect that synchronization turns Speed N_s3With motor speed N₃Difference, i.e. slippage N_s3-N₃More than threshold value Th, therefore, interrupt location 14 makes soft start list The output of unit 11 remains current partial objectives for rotating speed, thus is controlled the electric current of converter output by rotary speed controling unit 13 Frequency also remain ongoing frequency.Hereafter, along with the continuation of motor 20 is accelerated, N₃Become larger, slippage N_s3-N₃By Gradual change is little, and torque is gradually reduced the most therewith.The reason of torque drop is declining for the accelerating torque accelerated, therefore, Along with the decline of accelerating torque, when motor 20 torque capacity more than load torque and accelerating torque and time, motor 20 return to normal operating conditions.

On the other hand, the continuation along with motor is accelerated, along with tapering into of slippage, slippage N_s3’-N₃Less than threshold value Th Time, if currently a point acceleration time section terminates, then interrupt location 14 makes soft start unit 11 continue to put out next partial objectives for turn Speed, if currently a point acceleration time section is not over, then keeps current partial objectives for rotating speed.Along with soft start unit 11 exports The raising of partial objectives for rotating speed, the frequency of the electric current of converter output is also big with time-varying, i.e. from the curve L of Fig. 6₁Change to curve L₂.Motor 20 comes back to the accelerator of transducer drive, until synchronous rotational speed is the biggest with the difference of motor speed When threshold value Th, interrupt location 14 makes the output of soft start unit 11 remain current partial objectives for rotating speed again.So, Repeat above-mentioned operation, until motor 20 is finally reached the rotating speed of target of user's input always.

The multiple of the rated slip that the general value of threshold value Th is motor here, the preferably rated slip of motor 2～ 4 times, preferably 3 times of the rated slip of motor.The rated slip of motor refers to that motor is in rated speed, specified Slippage under Fu Zai.As a example by the most common motor, synchronous rotational speed is 4 grades of motor of 1500rpm, its rated speed For 1450rpm, his rated slip is 50 × 4/120=1.66Hz, and threshold value Th value is 3 times of the rated slip of motor If, it is 5Hz.

Threshold value given here is the preferably reference value drawn according to actual tests.In reality, the value of threshold value can be given above Centered by the reference value gone out, adjust up and down according to the working condition of motor.Specifically, first select one to be given above Reference threshold, if motor there occurs stall at work, the electric current i.e. detected constantly increases, and torque decline, Then show that this threshold value is excessive, this threshold value gradually should be turned down, until no longer there is stall.In contrast, if electronic In the accelerator of machine, soft start unit 11 remains current partial objectives for rotating speed continually so that the accelerator of motor Relatively slow, then show that this threshold value may be too small, this threshold value gradually should be heightened.Here the adjustment to threshold value is probably one repeatedly Process, constantly adjust the size of threshold value, until motor can accelerate to rotating speed of target rapidly.It addition, rotating speed control Device 10 processed can also arrange adjustment unit, realizes the method for adjustment to described threshold value by this adjustment unit.Thus, Threshold value can be automatically adjusted.

Fig. 7 is the flow chart of the method for controlling number of revolution of motor.Hereinafter, with reference to the Fig. 7 rotating speed control to the motor of the present invention Method processed illustrates.

In step SlOl, receive rotating speed of target and the acceleration time of motor.

In step SlO2, when this rotating speed of target received is more than the last rotating speed of target received, will accelerate Time is divided into multiple points of acceleration time sections.

In step SlO3, the rotating speed of target this received is converted into the most corresponding with multiple points of acceleration time sections multiple Partial objectives for rotating speed, each partial objectives for rotating speed both greater than receive this rotating speed of target moment output partial objectives for rotating speed, rear one Partial objectives for rotating ratio previous partial objectives for rotating speed is big, and last partial objectives for rotating speed is equal to this rotating speed of target received, output The time period of each partial objectives for rotating speed is corresponding with each point of acceleration time section.

In step SlO4, export kth partial objectives for rotating speed.

In step SlO5, the actual output speed of detection motor.

In step s 106, according to current partial objectives for rotating speed and the first difference of the actual output speed of motor, control defeated The actual output speed being sized such that motor going out the signal of telecommunication driving motor to rotate connects to current partial objectives for rotating speed Closely.

In step s 107, turn in the frequency of the signal of telecommunication corresponding with current partial objectives for rotating speed and the actual output of motor Second difference of the frequency corresponding to speed is more than or equal to, during prespecified threshold value (step S107:Y), return to step S104 Keep current partial objectives for rotating speed, when the second difference is less than prespecified threshold value (step S107:N), enter into step S108。

In step S108, it is judged that whether output is the n-th partial objectives for rotating speed, if the n-th partial objectives for rotating speed, I.e. k=n (step S108:Y), then return to step S104, if not if the n-th partial objectives for rotating speed (step S108: N), then step S109 is entered into.

In step S109, if currently a point acceleration time section terminates (step S109:Y), then enter into step S110, if A current point acceleration time section is not over (step S109:N), then return to the partial objectives for rotating speed that step S104 keeps current.

In step s 110, make k=k+1 again return to step S104, i.e. continue to put out next partial objectives for rotating speed.

If it should be noted that in step S108, it is judged that output is the n-th partial objectives for rotating speed (step S108:Y), Then in the present invention, the method for controlling number of revolution of motor can repeat the step of S104～S108, say, that always to motor Rotating speed be controlled, make the rotating speed of target that the stabilization of speed of motor receives in step S101.

Although the description of embodiments of the present invention, but this embodiment is intended only as example is suggested, and is not used to limit The scope of invention.This embodiment can be implemented with other various forms, in the scope of the main idea without departing from invention In, various omission can be carried out, replace, change.This embodiment and deformation thereof are contained in the scope of invention, main idea, The most also it is contained in the invention and the equal scope thereof that are recorded in patent claims.

Claims (9)

1. the revolution speed control device of a motor, it is characterised in that including:

Soft start unit, its rotating speed of target receiving motor and acceleration time, when described soft start unit, this receives When rotating speed of target is more than the last rotating speed of target received, is divided into multiple points of acceleration time sections this acceleration time, will This rotating speed of target received is converted into the multiple partial objectives for rotating speeds the most corresponding with multiple points of acceleration time sections, each subhead Mark rotating speed is both greater than the partial objectives for rotating speed that described soft start unit receives the moment output of this rotating speed of target, a rear partial objectives for Rotating ratio previous partial objectives for rotating speed is big, and last partial objectives for rotating speed is equal to this rotating speed of target received, soft start unit The time period exporting each partial objectives for rotating speed is corresponding with each point of acceleration time section；

Application of Motor Speed Detecting unit, the output speed of its detection motor；

Rotary speed controling unit, its output drives the signal of telecommunication that described motor rotates, and exports according to described soft start unit Current partial objectives for rotating speed and the first difference of the output speed of described motor of detecting of Application of Motor Speed Detecting unit, control Make the current partial objectives for that the output speed being sized such that described motor of the described signal of telecommunication exports to described soft start unit Rotating speed is close, and the current partial objectives for rotating speed that the frequency of the described signal of telecommunication exports with described soft start unit is corresponding；

Interrupt location, in the frequency of the described signal of telecommunication from described rotary speed controling unit with from Application of Motor Speed Detecting unit Second difference of the frequency corresponding to output speed of described motor more than or equal to prespecified threshold value time, make described soft The output of start unit remains current partial objectives for rotating speed.

2. the revolution speed control device of motor as claimed in claim 1, it is characterised in that

Described soft start unit calculates the partial objectives for rotating speed of output according to equation below (1), calculates according to equation below (2) Divide acceleration time section,

$N_{out}\left(k\right)=N_{out}^{\′}+k\frac{N_{in}-N_{out}^{\′}}{n}---\left(1\right)$

$T^{\′}=\frac{T}{n}---\left(2\right)$

Wherein, N '_outBe described soft start unit receive than on during the big rotating speed of target of the rotating speed of target that once receives Carve, the partial objectives for rotating speed of described soft start unit output,

N_inIt is for making motor speed increase this rotating speed of target received of described soft start unit,

N is the acceleration times of regulation, for the positive integer more than 1,

N_outK () represents the partial objectives for rotating speed that described soft start unit divides acceleration time section to export in kth, k is for being more than or equal to The positive integer of 1, the value of k is 1 ... n,

T ' represents each point of acceleration time section,

T represents this acceleration time received of soft start unit.

3. the revolution speed control device of motor as claimed in claim 1, it is characterised in that

Described threshold value is set to the multiple of the rated slip of described motor.

4. the revolution speed control device of motor as claimed in claim 3, it is characterised in that

Described threshold value is set to 2～4 times of the rated slip of described motor.

5. the revolution speed control device of the motor as described in any one in Claims 1 to 4, it is characterised in that

In the relation of the output speed of described motor and the output voltage of described rotary speed controling unit, described motor has rule Fixed characteristic,

In the characteristic of described regulation, along with the output voltage of the described rotary speed controling unit that accelerates of the output speed of described motor Also uprising, when the output speed of described motor reaches more than rated speed, the output voltage of described rotary speed controling unit is with Big value is saturated.

6. the method for controlling number of revolution of a motor, it is characterised in that including:

Soft start step, its rotating speed of target receiving motor and acceleration time, when this rotating speed of target received is more than upper During the rotating speed of target once received, is divided into multiple points of acceleration time sections, the target this received the described acceleration time Rotating speed is converted into the multiple partial objectives for rotating speeds the most corresponding with multiple points of acceleration time sections, and each partial objectives for rotating speed both greater than receives The partial objectives for rotating speed exported to the moment of this rotating speed of target, a rear partial objectives for rotating ratio previous partial objectives for rotating speed is big, last Individual partial objectives for rotating speed is equal to this rotating speed of target received, and exports time period of each partial objectives for rotating speed when accelerating with each point Between section corresponding；

Application of Motor Speed Detecting step, the output speed of detection motor；

Rotating speed rate-determining steps, its output drives the signal of telecommunication that described motor rotates, and according to current partial objectives for rotating speed and institute State the first difference of the output speed of motor, control the output speed being sized such that described motor of the described signal of telecommunication to Current partial objectives for rotating speed is close, and the frequency of the described signal of telecommunication is corresponding with current partial objectives for rotating speed；

Interrupt step is big in the second difference of the frequency corresponding to the frequency of the described signal of telecommunication and the output speed of described motor When equal to prespecified threshold value, keep current partial objectives for rotating speed.

7. the method for controlling number of revolution of motor as claimed in claim 6, it is characterised in that

In described soft start step, calculate the partial objectives for rotating speed of output according to equation below (1), according to equation below (2) Calculate a point acceleration time section,

$N_{out}\left(k\right)=N_{out}^{\′}+k\frac{N_{in}-N_{out}^{\′}}{n}---\left(1\right)$

$T^{\′}=\frac{T}{n}---\left(2\right)$

Wherein, N '_outBe receive than on the partial objectives for of moment output of the big rotating speed of target of the rotating speed of target that once receives Rotating speed,

N_inIt is for making motor speed increase and rotating speed of target that this receives,

N is the acceleration times of regulation, for the positive integer more than 1,

N_outK () represents that k is the positive integer more than or equal to 1, k at the partial objectives for rotating speed that kth divides acceleration time section to export Value be 1 ... n,

T ' represents each point of acceleration time section,

T represents this acceleration time received.

8. the method for controlling number of revolution of motor as claimed in claim 6, it is characterised in that

Described threshold value is set to the multiple of the rated slip of described motor.

9. the method for controlling number of revolution of motor as claimed in claim 8, it is characterised in that

Described threshold value is set to 2～4 times of the rated slip of described motor.