CN106856394A - AC variable-frequency speed regulation system and method - Google Patents
AC variable-frequency speed regulation system and method Download PDFInfo
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- CN106856394A CN106856394A CN201510908785.7A CN201510908785A CN106856394A CN 106856394 A CN106856394 A CN 106856394A CN 201510908785 A CN201510908785 A CN 201510908785A CN 106856394 A CN106856394 A CN 106856394A
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P5/00—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors
- H02P5/46—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors for speed regulation of two or more dynamo-electric motors in relation to one another
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Abstract
The present invention provides a kind of AC variable-frequency speed regulation system and method, adjusts the frequency of supply of the first AC driven power and/or the second AC driven power by the first inversion unit and the second inversion unit to adjust the synchronous rotational speed n of the first motors1And/or second motor synchronous rotational speed ns2, so that the actual speed n of the first motor and the second motor is adjusted, | ns1- n |=| n-ns2|, can be in the range of the torque capacity of the first motor and the second motor, the actual speed of the first motor of any regulation and the second motor, speed adjustable range is broad.
Description
Technical field
The present invention relates to electric machine speed regulation technology, more particularly to a kind of AC variable-frequency speed regulation system and method.
Background technology
With the development of national economy and science and technology, widely used in the every field of national product
The electric actuator with motor as prime mover, such as communications and transportation, industrial and agricultural production, national defence space flight
Etc. various aspects.The extensive use of electric actuator had both improve production efficiency and product quality, subtracted again
The light working strength of working people.Adjustable speed Electrified Transmission is carried out using alternating current generator, is not only realized
Rotational speed regulation scope wider, control accuracy higher, faster the features such as dynamic response, but also gram
The shortcomings of direct current generator capacity is small, difficult in maintenance, commutation has spark is taken.
Threephase asynchronous pressure and speed regulating system, when the parameter constant of asynchronous machine equivalent circuit,
Under identical rotating speed, electromagnetic torque and stator voltage square are directly proportional, with change stator applied voltage come
Change the functional relation of mechanical property, so as to change rotating speed of the motor under certain load torque.This tune
Speed system has circuit structure simple, excellent with the high, smooth speed control of convenient, with low cost, reliability etc.
Point.
When adjusting the rotating speed of motor using threephase asynchronous pressure and speed regulating system, regulation motor stator
During phase voltage virtual value, the breakdown slip s of motormWith synchronous rotational speed n1All it is invariable, makes electricity
Speed adjustable range of the machine under constant load can only be in 0~smBetween, speed adjustable range is narrower, not broad enough.
The content of the invention
The present invention provides a kind of AC variable-frequency speed regulation system and method, by adjusting the first AC driven power
And/or second the frequency of supply of AC driven power adjust the synchronous rotational speed n of the first motors1And/or second
The synchronous rotational speed n of motors2, so that the actual speed n of the first motor and the second motor is adjusted, can be
In the range of the torque capacity of one motor and the second motor, the reality of the first motor of any regulation and the second motor
Rotating speed, speed adjustable range is broad.
First aspect present invention provides a kind of AC variable-frequency speed regulation system, including：It is rectification unit, first inverse
Become unit, the second inversion unit, the first motor and the second motor；
Rectification unit is connected with the first inversion unit and the second inversion unit respectively, the first inversion unit and
One motor connection, the second inversion unit and the second motor connection, the first motor and the second motor coaxle connect
Connect；
Rectification unit is used to the AC driven power of input is converted into direct current driving power supply and is separately input into
First inversion unit and the second inversion unit；
First inversion unit is used to that direct current driving power supply to be converted to the first exchange driving for driving the first motor
Power supply, the second inversion unit is used to that direct current driving power supply to be converted to the second exchange drive for driving the second motor
The power supply phase sequence of dynamic power supply, the first AC driven power and the second AC driven power is identical, the first exchange
The frequency of supply of driving power supply is f1, the frequency of supply of the second AC driven power is f2, by regulation the
The frequency of supply of one AC driven power and/or the second AC driven power adjusts the synchronization of the first motor
Rotating speed ns1And/or the synchronous rotational speed n of second motors2, so as to adjust the first motor and the second motor
Actual speed n, | ns1- n |=| n-ns2|。
Second aspect present invention provides a kind of ac variable frequency speed regulation method, is applied to ac variable frequency speed regulation system
System, AC variable-frequency speed regulation system includes：Rectification unit, the first inversion unit, the second inversion unit,
One motor and the second motor；
Rectification unit is connected with the first inversion unit and the second inversion unit respectively, the first inversion unit and
One motor connection, the second inversion unit and the second motor connection, the first motor and the second motor coaxle connect
Connect；
Rectification unit is used to the AC driven power of input is converted into direct current driving power supply and is separately input into
First inversion unit and the second inversion unit, the first inversion unit are used to for direct current driving power supply to be converted to drive
First AC driven power of dynamic first motor, the second inversion unit is used to be converted to direct current driving power supply
Drive the second AC driven power of the second motor；
Ac variable frequency speed regulation method includes：
AC driven power is input into rectification unit, so that rectification unit is converted to AC driven power
Direct current driving power supply is simultaneously separately input into the first inversion unit and the second inversion unit；
Adjusted by adjusting the frequency of supply of the first AC driven power and/or the second AC driven power
The synchronous rotational speed n of the first motors1And/or second motor synchronous rotational speed ns2, so that adjust the first motor and
The actual speed n of the second motor, | ns1- n |=| n-ns2|, the frequency of supply of the first AC driven power is
f1, the frequency of supply of the second AC driven power is f2, ns1=60f1/p1, ns2=60f2/p2, the first exchange
Driving power supply is identical with the power supply phase sequence of the second AC driven power.
Brief description of the drawings
Fig. 1 is the structure chart of AC variable-frequency speed regulation system of the invention；
Fig. 2 is the speed regulating control schematic diagram of AC variable-frequency speed regulation system of the invention；
Fig. 3 is the flow chart of ac variable frequency speed regulation method of the invention.
Description of reference numerals：
1：Rectification unit；
2：First inversion unit；
3：Second inversion unit；
4：First motor；
5：Second motor；
6：DC filtering unit；
7：Shaft coupling.
Specific embodiment
To make the purpose, technical scheme and advantage of the embodiment of the present invention clearer, below in conjunction with this hair
Accompanying drawing in bright embodiment, is clearly and completely described to the technical scheme in the embodiment of the present invention,
Obviously, described embodiment is a part of embodiment of the invention, rather than whole embodiments.It is based on
Embodiment in the present invention, those of ordinary skill in the art are obtained under the premise of creative work is not made
The every other embodiment for obtaining, belongs to the scope of protection of the invention.
In existing Alternating Current Governor System, regulation motor rotating speed is realized with asynchronous machine stator voltage is changed
Control system be referred to as pressure and speed regulating system, this governing system have circuit structure it is simple, with it is convenient,
With low cost, reliability is high, smooth speed control the advantages of.The electromagnetic torque T of asynchronous machineeExpression formula is：
In formula, npIt is stator winding number of pole-pairs；U1It is stator phase voltage virtual value；f1It is stator voltage
Frequency；r1It is the every phase winding internal resistance of stator；X1It is the every phase leakage reactance of stator；r′2And X'20For rotor is converted
To every phase resistance of stator side and per phase leakage reactance；S is revolutional slip, and revolutional slip expression formula is：
In formula, n1It is the synchronous rotational speed of motor, n is the actual speed of motor, constant in other specification
In the case of electromagnetic torque TeWith stator phase voltage virtual value U1Square be directly proportional.It is certain in load torque
In the case of, stator phase voltage virtual value U1Change cause the change of motor slip ratio s, it is and synchronous
Rotating speed n1Unchanged, then motor speed n changes.
Embodiment one
Fig. 1 is the structure chart of the AC variable-frequency speed regulation system of the embodiment of the present invention one, as shown in figure 1, this
The AC variable-frequency speed regulation system of embodiment, including：Rectification unit 1, the first inversion unit 2, second are inverse
Become unit 3, the first motor 4 and the second motor 5；
Rectification unit 1 is connected with the first inversion unit 2 and the second inversion unit 3 respectively, the first inversion list
The motor 4 of unit 2 and first is connected, and the second inversion unit 2 and the second motor 5 are connected, the He of the first motor 4
Second motor 5 is coaxially connected；
Rectification unit 1 is used to the AC driven power of input is converted into direct current driving power supply and is input into respectively
To the first inversion unit 2 and the second inversion unit 3；
First inversion unit 2 is used to that direct current driving power supply to be converted to the first exchange for driving the first motor 4
Driving power supply, the second inversion unit 3 is used to being converted to direct current driving power supply and drives the of the second motor 5
The power supply phase sequence of two AC driven powers, the first AC driven power and the second AC driven power is identical,
The frequency of supply of the first AC driven power is f1, the frequency of supply of the second AC driven power is f2, lead to
The frequency of supply of first AC driven power and/or second AC driven power is overregulated to adjust
Save the synchronous rotational speed n of first motors1And/or the synchronous rotational speed n of second motors2, so as to adjust
The actual speed n of first motor and second motor, | ns1- n |=| n-ns2|。
Specifically, rectification unit 1 is mainly made up of IGBT and diode, and the exchange for that will be input into is driven
Dynamic Power convert is direct current driving power supply and is separately input into the first inversion unit 2 and the second inversion unit
3。
First inversion unit 2 is mainly made up of IGBT and diode, for direct current driving power supply to be changed
To drive the first AC driven power of the first motor 4, the second inversion unit 3 is main by IGBT and two
Pole pipe is constituted, and drives the second exchange of the second motor 5 to drive electricity for direct current driving power supply to be converted to
Source, wherein, the power supply phase sequence of the first AC driven power and the second AC driven power is identical, and first hands over
The frequency of supply for flowing driving power supply is f1, the frequency of supply of the second AC driven power is f2, by regulation
The frequency of supply of first AC driven power and/or second AC driven power is described to adjust
The synchronous rotational speed n of the first motors1And/or the synchronous rotational speed n of second motors2, so as to adjust described
The actual speed n of one motor and second motor, | ns1- n |=| n-ns2|。
Fig. 2 is the speed regulating control schematic diagram of the AC variable-frequency speed regulation system of the embodiment of the present invention one.
With reference to Fig. 2, the speed governing control of the AC variable-frequency speed regulation system of the embodiment of the present invention one is illustrated
Principle processed.
Start the first motor and the second motor, adjusted respectively by the first inversion unit and the second inversion unit
The confession of the first AC driven power for driving the first motor and the second AC driven power for driving the second motor
Electric frequency, makes the first motor stabilizing operate in motoring condition, and the second motor stabilizing operates in generating state.
Assume that the parameter of the first motor and the second motor is similar in theory analysis, mechanical property is similar, because
This, the straight line portion of the mechanical characteristic of the first motor and the second motor is parallel to each other, as shown in Figure 2
Go out：
Wherein, straight line A1B1It is the straight line portion of the mechanical characteristic of the first motor, straight line A2B2For
The straight line portion of the mechanical characteristic of the second motor, now, the first motor is in motoring condition, second
Motor is in generating state, under the preferable operating mode for not considering loss, when the first motor reaches with the second motor
To balance, in the case of stable operation, the first motor is equal in magnitude with the electromagnetic torque of the second motor, side
To opposite.
Such as Fig. 2, A1And A2The respectively stable operating point of the first motor and the second motor, Te1And Te2Point
Not Wei the first motor and the second motor stabilizing operate in operating point A1And A2When corresponding electromagnetic torque, now
Te1=-Te2, ns1And ns2The respectively synchronous rotational speed of the first motor and the second motor, ns1And ns2It is respectively depending on
The frequency for driving the first AC driven power of the first motor and the second exchange for driving the second motor drive electricity
The frequency in source；Due to two motor coaxle connections, when the first motor and the second motor stabilizing operate in work
Point A1And A2When, the first motor and the actual rotating speed of the second motor are equal, are n.
Due to the straight line portion A of the mechanical characteristic of the first motor1B1Mechanical property with the second motor is bent
The straight line portion A of line2B2Be parallel to each other, and do not consider loss preferable operating mode under, the first motor and
Second motor reaches balance, and electromagnetic torque during stable operation is equal in magnitude, in the opposite direction.Therefore have,Congruent triangles corresponding sides are equal, so as to there is B1O=B2O, i.e., | ns1- n |=| n-ns2|,
With reference tos1And s2It is the first motor M1 and the revolutional slip of the second motor M2, therefore
Have：
|s1ns1|=| s2ns2| (1)
In formula (1), s1And s2It is the first motor M1 and the revolutional slip of the second motor M2, ns1, ns2Point
Wei not synchronization of first motor when the first AC driven power and the second motor are in the second AC driven power
Rotating speed, wherein：ns1=60f1/p1；ns2=60f2/p2, wherein：f1、f2Respectively the first of the first motor
The frequency of supply of the second AC driven power of the frequency of supply of AC driven power and the second motor, p1、
p2The motor number of pole-pairs of respectively the first motor, the second motor, during following analysis, it is assumed that the
The motor number of pole-pairs of one motor and the second motor is equal, i.e. p1=p2。
By ns1=60f1/p1；ns2=60f2/p2Formula (1) is substituted into, and notices s2<0, then can obtain：
s1f1=-s2f2 (2)
Because tested motor and load motor coaxially couple, therefore two motor actual speed ns are identical, and due to
N=(1-s1)ns1=(1-s2)ns2, ns1=60f1/p1, ns2=60f2/p2, so：
60f1(1-s1)/p1=60f2(1-s2)/p2 (3)
p1=p2, obtained by abbreviation：
(1-s1)f1=(1-s2)f2 (4)
Formula (2) is substituted into formula (4), is obtained：
s1=f1-f2/2f1=Δ f/2f1 (5)
s2=f2-f1/2f2=-Δ f/2f2 (6)
Wherein：Δ f=f1-f2
Further, can be obtained by the relation of each parameter of asynchronous machine：
In formula (7), I '2It is rotor current reduced value, A；E1It is stator emf phase, V；ω1、ω2
It is stator, rotor current angular frequency, rad/s, R '2It is rotor resistance reduced value, Ω；L′2For rotor leaks electricity
Sense reduced value, H；S is revolutional slip, dimensionless, s=ω2/ω1。
No-load current is：
I0=E1/ω1Lm=E1/2πf1Lm (8)
In formula (8), LmIt is magnetizing inductance, H.
Stator current is：
During frequency control is carried out, the magnetic flux of electric machine stator iron is maintained to keep constant, therefore E1
With f1Ratio be constant constant C.Make E1/f1=C, C1=C/2 π Lm, C2=C/2 π, Then formula (9) can be with abbreviation：
Therefore, it can obtain the stator current I of the first motor11, i.e.,
In formula (11), ω11It is the stator current angular frequency of the first motor, ω11=2 π f1, by formula (5)
Formula (11) is substituted into, then can be obtained：
Similarly can be in the hope of the stator current of the second motor, i.e.,：
Again due to the electromagnetic torque T of motoreWith electromagnetic power PeWith synchronous angular velocity Ω1Between relation be：
Formula (7) is substituted into formula (14) can then obtain：
In formula (15),
Formula (5) is substituted into formula (15), then can obtain the electromagnetic torque of the first motor, i.e.,：
Similarly can be in the hope of the electromagnetic torque of the second motor, i.e.,：
Further, according to formula (16), T is soughte1To the derivative of Δ f, i.e.,：
Make (Te1)'<0, then have：
T can also similarly be tried to achievee2To the derivative of Δ f, i.e.,：
Make (Te2)'<0, then have：
Therefore, according to formula (19) and formula (21), when Δ f is in [0, R '2/πL′2] interval change when, Te1
It is the monotonic increasing function of Δ f, Te2It is the monotonous descending function of Δ f, and total energy keeps in change procedure
Te1=-Te2。
Verified by theory analysis, according to formula (16) and formula (17) and combine Fig. 2, it can be seen that
First motor and the second motor reach balance, stable operation in A1 points and A2 points, the first motor and
The electromagnetic torque of two motors is equal in magnitude, in the opposite direction.And the first motor M1, the second motor M2's
Electromagnetic torque is totally dependent on Δ f, by adjusting first AC driven power and/or second friendship
The frequency of supply of driving power supply is flowed to adjust the synchronous rotational speed n of first motors1And/or second electricity
The synchronous rotational speed n of machines2, so that the actual speed n of first motor and second motor is adjusted,
|ns1- n |=| n-ns2|。
For example：Do not changing the frequency of supply f of the second AC driven power for driving the second motor2Situation
Under, the frequency f of the first AC driven power for driving the first motor is adjusted by the first inversion unit1If, the
The frequency f of one AC driven power1Raise, the synchronous rotational speed n of the first motors1Increase, the first motor
Mechanical characteristic will be translated up along the positive direction of y-axis, i.e. straight line A1B1Along y-axis positive direction to
Upper translation, the first motor changes therewith with the stable operating point of the second motor, when the first motor and
Two motors reach next balance, during stable operation, under the preferable operating mode for not considering loss, at the moment
Stable operating point, the electromagnetic torque of the first motor and the second motor it is equal in magnitude, in the opposite direction；Together
When | ns1- n |=| n-ns2|, because the synchronous rotational speed of the first motor is raised, the mechanical characteristic of the first motor
Upper shifting, therefore, the actual speed of the first motor and the second motor is raised accordingly, the first motor and second
The electromagnetic torque of motor becomes big therewith.Now, the electromagnetic torque in the first motor and the second motor is less than most
In the case of big torque, it is possible to achieve any regulation of rotating speed, speed adjustable range is broader.
Likewise, not changing the frequency of supply f of the second AC driven power for driving the second motor2Situation
Under, the frequency f of the first AC driven power for driving the first motor is adjusted by the first inversion unit1If, the
One electric machine frequency f1Reduce, then the synchronous rotational speed n of the first motors1Decrease, the mechanical property of the first motor
Curve will downwards be translated along the negative direction of y-axis, i.e. straight line A1B1Translated downwards along the negative direction of y-axis,
First motor changes therewith with the stable operating point of the second motor, when the first motor and the second motor reach
To next balance, during stable operation, under the preferable operating mode for not considering loss, stabilization fortune at the moment
The electromagnetic torque of row point, the first motor and the second motor it is equal in magnitude, in the opposite direction；Simultaneously
|ns1- n |=| n-ns2|, due to the synchronous rotational speed reduction of the first motor, under the mechanical characteristic of the first motor
Move, therefore, the actual speed of the first motor and the second motor is reduced accordingly, and the first motor is electric with second
The electromagnetic torque of machine diminishes therewith.Now, the electromagnetic torque in the first motor and the second motor is less than maximum
In the case of torque, it is possible to achieve any regulation of rotating speed, speed adjustable range is broader.
For example, it is also possible to not change the frequency of supply f of the first AC driven power for driving the first motor1
In the case of, the frequency of the second AC driven power for driving the second motor is adjusted by the second inversion unit
f2, make f2Raise or reduce, the synchronous rotational speed n of the second motors2Accordingly increase or reduce, machinery is special
The parallel upper shifting of the corresponding positive direction along y-axis of linearity curve or along y-axis negative direction it is parallel move down, the
One motor changes therewith with the stable operating point of the second motor, when the first motor and the second motor reach
Next balance, during stable operation, under the preferable operating mode for not considering loss, stable operation at the moment
The electromagnetic torque of point, the first motor and the second motor it is equal in magnitude, in the opposite direction；Simultaneously
|ns1- n |=| n-ns2|, the actual speed increase accordingly or reduction of the first motor and the second motor, electromagnetism turn
Square increase accordingly reduces.Now, the electromagnetic torque in the first motor and the second motor turns less than maximum
In the case of square, it is possible to achieve any regulation of rotating speed, speed adjustable range is broader.
Again for example, f can be adjusted simultaneously by the first inversion unit and the second inversion unit1And f2, now,
The synchronous rotational speed n of the first motor and the second motors1、ns2By with the frequency f of the first AC driven power1With
The frequency f of the second AC power1Change and change, so, the mechanical property of the first motor and the second motor
Curve will respectively along y-axis it is parallel it is upper shifting or move down, the stable operating point of the first motor and the second motor is therewith
Change, when the first motor and the second motor reach next balance, during stable operation, do not considering
Under the preferable operating mode of loss, stable operating point at this moment, the electromagnetic torque of the first motor and the second motor
It is equal in magnitude, in the opposite direction；Simultaneously | ns1- n |=| n-ns2|, the reality of the first motor and the second motor turns
Fast corresponding increase reduces, and electromagnetic torque increases or reduces accordingly.Now, in the first motor and
The electromagnetic torque of two motors is less than in the case of torque capacity, it is possible to achieve any regulation of rotating speed, speed governing
Wider range is wide
Further, in these cases, can also be by the first inversion unit and the second inversion unit
F is adjusted simultaneously1And f2When, it is ensured that Δ f is constant, so, the synchronous rotational speed n of the first motor and the second motors1、
ns2By with the frequency f of the first AC driven power1With the frequency f of the second AC power1Change and change,
But the synchronous rotational speed n of the first motor and the second motors1、ns2Difference keep constant, the first motor and the
The mechanical characteristic of two motors is by entirety is along the parallel upper shifting of y-axis or moves down, the first motor and the second motor
Stable operating point change therewith, when the first motor and the second motor reach next balance, stabilization
Move or move down during operation, on the first motor is corresponding to the stable operating point of the second motor, do not considering loss
Preferable operating mode under, stable operating point at this moment, the electromagnetic torque of the first motor and the second motor it is big
It is small equal, in the opposite direction；Simultaneously | ns1- n |=| n-ns2|, the actual speed phase of the first motor and the second motor
The change answered.In such a case, because Δ f is constant, corresponding electromagnetic torque is constant.So, in electricity
In the range of speeds that machine is allowed, it is possible to achieve any regulation of rotating speed, speed adjustable range is broader.
Therefore, the AC variable-frequency speed regulation system that the present invention is provided, electricity is driven by adjusting first exchange
Synchronization of the frequency of supply of source and/or second AC driven power to adjust first motor turns
Fast ns1And/or the synchronous rotational speed n of second motors2, so as to adjust first motor and described
The actual speed n of two motors, | ns1- n |=| n-ns2|.The model of torque capacity can be in electromagnetic torque
In enclosing, the actual speed of any regulation motor of frequency of supply by adjusting the first motor and the second motor,
Speed adjustable range is broader.
Further, according to formula (16) and (17), as Δ f ＞ 0, i.e. f1>f2When, Te1>0,
First motor operation first quartile, i.e. the first motor are in motoring condition, now, Te2<0, second
The quadrant of motor operation second, i.e. the second motor are in generating state.
Correspondingly, as Δ f ＜ 0, i.e. f1<f2When, Te1<0, first the second quadrant of motor operation, i.e.,
One motor is in generating state, now, Te2>0, the second motor operation first quartile, i.e. the second motor
In motoring condition.
For example, in fig. 2, after the first motor and the second electric motor starting, stable operation is in A1 points respectively
With A2 points, now Δ f ＞ 0, i.e. f1>f2When, Te1>0, the first motor operation first quartile, i.e., first
Motor is in motoring condition, Te2<0, second the second quadrant of motor operation, i.e. the second motor is in and generates electricity
State.
Stable operation is distinguished in the case of A1 points, A2, by first in the first motor and the second motor
Inversion unit regulation drives the frequency of the first AC driven power of the first motor operation, makes f1Gradually subtract
Small, the second inversion unit changes the frequency f of the second AC driven power for driving the second motor operation2, make
f2Gradually increase, reduce Δ f, and final first motor and the second motor reach steadily, stable operation
When, make Δ f ＜ 0, with reference to Fig. 2, in whole speed regulation process, the mechanical characteristic of the first motor will
Move gradually downward, and gradually as the second quadrant extends, correspondingly, the mechanical characteristic of the second motor
To gradually move up, and extend to first quartile, when the first motor and the second motor reach steadily, surely
When running surely, Δ f ＜ 0, corresponding Te1<0, Te2>0, so, the first motor stabilizing operates in second
Quadrant, the first motor stabilizing operates in first quartile.
Further, it is also possible to pass through the first inversion unit and the second inversion unit change the first motor operation of driving
The first AC driven power and drive the second motor operation the second AC driven power power supply phase sequence,
The rotating of the first motor and the second motor is realized, the first motor and the second motor stabilizing is operated in the 3rd
Quadrant or fourth quadrant.For example, referring to Fig. 2, first quartile and second are operated in the first motor stabilizing
In the case that motor stabilizing operates in the second quadrant, changed by the first inversion unit and the second inversion unit
The first AC driven power for driving the first motor operation and the second exchange for driving the second motor operation drive
The power supply phase sequence of power supply so that the first motor and the second motor reversal, rotating speed is less than 0, the first motor fortune
, in fourth quadrant, the second motor operation is in third quadrant for row.Again for example, being operated in the first motor stabilizing
In the case that second quadrant and the second motor stabilizing operate in first quartile, by the first inversion unit and
Two inversion units change the second motor operation of the first AC driven power and driving for driving the first motor operation
The second AC driven power power supply phase sequence so that the first motor and the second motor reversal, rotating speed are less than
0, in third quadrant, the second motor operation is in fourth quadrant for the first motor operation.
Therefore, the AC variable-frequency speed regulation system that the present embodiment one is provided can realize the four-quadrant fortune of motor
OK, and speed adjustable range is wider.
The AC variable-frequency speed regulation system that the present invention is provided, including：Rectification unit, the first inversion unit,
Two inversion units, the first motor and the second motor；
Rectification unit is connected with the first inversion unit and the second inversion unit respectively, the first inversion unit and
One motor connection, the second inversion unit and the second motor connection, the first motor and the second motor coaxle connect
Connect；
Rectification unit is used to the AC driven power of input is converted into direct current driving power supply and is separately input into
First inversion unit and the second inversion unit；
First inversion unit is used to that the direct current driving power supply to be converted to the first exchange for driving the first motor
Driving power supply, the second inversion unit is used to that direct current driving power supply to be converted to the second friendship for driving the second motor
The power supply phase sequence of stream driving power supply, the first AC driven power and the second AC driven power is identical, described
The frequency of supply of the first AC driven power is f1, the frequency of supply of second AC driven power is
f2, adjusted by adjusting the frequency of supply of the first AC driven power and/or second AC driven power
Save the synchronous rotational speed n of first motors1And/or the synchronous rotational speed n of second motors2, so as to adjust
The actual speed n of first motor and second motor, | ns1- n |=| n-ns2|.By then passing through
The rotating speed of the further regulation motor of regulation frequency of supply, therefore, it can any in the range of torque capacity
Regulation so that the rotational speed regulation scope of motor is broader.Additionally, driving electricity by the exchange of regulation first
Source and the power supply phase sequence of the second AC driven power, can also realize the rotating of motor, therefore, also can
Enough realize the four quadrant running of motor.
Alternatively, the AC variable-frequency speed regulation system that the embodiment of the present invention one is provided, rectification unit is inverse with first
Becoming also includes DC filtering unit 6 between unit and the second inversion unit, DC filtering unit 6 is used to filter
Except the AC compounent in DC power supply.
DC filtering unit 6 mainly includes electric capacity and inductance, and the exchange that rectification unit 1 will be input into drives electricity
Source is converted to direct current driving power supply, and direct current driving power supply now is pulsating direct current driving power supply, by straight
After stream filter unit 6, DC filtering unit 6 filters the AC compounent in direct current driving power supply so that straight
Stream driving power supply is more smoothed.
Further, the embodiment of the present invention one provide AC variable-frequency speed regulation system, the first inversion unit and
Direct current common bus connection between second inversion unit；
When the first motor is in power supply state, the second motor is in generating state, what the second motor was produced
Electric energy is delivered to the first inversion unit by the second inversion unit and dc bus；
When the second motor is in power supply state, the first motor is in generating state, what the first motor was produced
Electric energy is delivered to second inversion unit by the first inversion unit and dc bus.
Based on above-mentioned analysis, the electromagnetic torque of the first motor and the second motor is equal in magnitude all the time, direction phase
Instead, i.e., when the first motor is in power supply state, the second motor is in generating state, now the second motor
The electric energy of generation is just delivered to the first inversion unit by the second inversion unit and dc bus.
Or when the second motor is in power supply state, the first motor is in generating state, the first motor
The electric energy of generation is delivered to second inversion unit by the first inversion unit and dc bus.
So, connected by by direct current common bus between the first inversion unit and the second inversion unit, realized
The two-way flow of energy so that the electric energy that the motor in generating state is produced can by inversion unit
Another inversion unit being connected with motoring condition is delivered to dc bus, the double of energy are realized
To flowing so that the capacity usage ratio of the AC variable-frequency speed regulation system that the present invention is provided is higher, more saves
Energy.
Alternatively, the AC variable-frequency speed regulation system that the embodiment of the present invention one is provided, the first motor and the second electricity
Machine is coaxially connected by shaft coupling 7.
Embodiment two
Fig. 3 is the flow chart of the ac variable frequency speed regulation method that the embodiment of the present invention two is provided.
Fig. 3 is refer to, the embodiment of the present invention two provides a kind of ac variable frequency speed regulation method, is applied to this hair
The AC variable-frequency speed regulation system of bright embodiment one, above-mentioned ac variable frequency speed regulation method includes：
S1:AC driven power is input into rectification unit, so that rectification unit turns AC driven power
It is changed to direct current driving power supply and is separately input into the first inversion unit and the second inversion unit；
S2:Adjusted by adjusting the frequency of supply of the first AC driven power and/or the second AC driven power
Save the synchronous rotational speed n of the first motors1And/or the synchronous rotational speed n of second motors2, so as to adjust first
The actual speed n of motor and the second motor, | ns1- n |=| n-ns2|, the power supply of the first AC driven power is frequently
Rate is f1, the frequency of supply of the second AC driven power is f2, ns1=60f1/p1, ns2=60f2/p2, the
The power supply phase sequence of one AC driven power and the second AC driven power is identical.
Specifically speed regulating method is no longer gone to live in the household of one's in-laws on getting married herein such as the principle of speed regulating control as embodiment one is described
State.
The present invention provide ac variable frequency speed regulation method, by adjust first AC driven power and/
Or the frequency of supply of second AC driven power adjusts the synchronous rotational speed n of first motors1With/
Or the synchronous rotational speed n of second motors2, so as to adjust the reality of first motor and second motor
Border rotating speed n, | ns1- n |=| n-ns2|.Can be in the range of torque capacity in electromagnetic torque, by adjusting
The actual speed of any regulation motor of the frequency of supply of the first motor and the second motor is saved, speed adjustable range is wider
Extensively.
Additionally, the ac variable frequency speed regulation method that the present invention is provided, can realize the four quadrant running of motor.
Further, the ac variable frequency speed regulation method that the embodiment of the present invention two is provided, also includes：In rectification
DC filtering unit, DC filtering unit are set between unit and the first inversion unit and the second inversion unit
For filtering the AC compounent in DC power supply.
The AC driven power of input is converted to direct current driving power supply by rectification unit, DC driven now
Power supply is pulsating direct current driving power supply, by after DC filtering unit, DC filtering unit filters direct current drive
AC compounent in dynamic power supply so that direct current driving power supply is more smoothed.
Further, the ac variable frequency speed regulation method that the embodiment of the present invention two is provided, also includes：By first
Direct current common bus connection is carried out between inversion unit and the second inversion unit；
When the first motor is in power supply state, the second motor is in generating state, what the second motor was produced
Electric energy is delivered to the first inversion unit by the second inversion unit and dc bus；
When the second motor is in power supply state, the first motor is in generating state, what the first motor was produced
Electric energy is delivered to the second inversion unit by the first inversion unit and the dc bus.
So, connected by by direct current common bus between the first inversion unit and the second inversion unit, realized
The two-way flow of energy so that the electric energy that the motor in generating state is produced can by inversion unit
Another inversion unit being connected with motoring condition is delivered to dc bus, the double of energy are realized
To flowing so that the capacity usage ratio of the AC variable-frequency speed regulation system that the present invention is provided is higher, more saves
Energy.
Further, the ac variable frequency speed regulation method that the embodiment of the present invention two is provided, the first motor and second
Motor is coaxially connected by shaft coupling.
Finally it should be noted that：Various embodiments above is merely illustrative of the technical solution of the present invention, rather than right
Its limitation；Although being described in detail to the present invention with reference to foregoing embodiments, this area it is common
Technical staff should be understood：It can still be repaiied to the technical scheme described in foregoing embodiments
Change, or equivalent is carried out to which part or all technical characteristic；And these are changed or replace
Change, do not make the scope of the essence disengaging various embodiments of the present invention technical scheme of appropriate technical solution.
Claims (10)
1. a kind of AC variable-frequency speed regulation system, it is characterised in that including：Rectification unit, the first inversion
Unit, the second inversion unit, the first motor and the second motor；
The rectification unit is connected with first inversion unit and second inversion unit respectively, described
First inversion unit and first motor connection, second inversion unit and second motor connect
Connect, first motor and second motor coaxle are connected；
The rectification unit is used to for the AC driven power of input to be converted to direct current driving power supply and difference is defeated
Enter to first inversion unit and second inversion unit；
First inversion unit is used to for the direct current driving power supply to be converted to driving first motor
First AC driven power, second inversion unit is used to for the direct current driving power supply to be converted to driving
Second AC driven power of second motor, first AC driven power is exchanged with described second
The power supply phase sequence of driving power supply is identical, and the frequency of supply of first AC driven power is f1, described
The frequency of supply of two AC driven powers is f2, by adjusting first AC driven power and/or described
The frequency of supply of the second AC driven power adjusts the synchronous rotational speed n of first motors1And/or it is described
The synchronous rotational speed n of the second motors2, so as to adjust the actual speed of first motor and second motor
N, | ns1- n |=| n-ns2|。
2. AC variable-frequency speed regulation system according to claim 1, it is characterised in that regulation is described
The frequency of supply of the first AC driven power and/or second AC driven power, including：
The frequency of supply for adjusting first AC driven power by first inversion unit is f1, with
Adjust the synchronous rotational speed n of first motors1, so as to adjust the first motor and the second motor reality
Rotating speed n, | ns1- n |=| n-ns2|, or,
The frequency of supply for adjusting second AC driven power by second inversion unit is f2, with
Adjust the synchronous rotational speed n of second motors2, so as to adjust the first motor and the second motor reality
Rotating speed n, | ns1- n |=| n-ns2|, or,
The frequency of supply for adjusting first AC driven power by first inversion unit is f1, with
Adjust the synchronous rotational speed n of first motors1, second exchange is adjusted by second inversion unit
The frequency of supply of driving power supply is f2, to adjust the synchronous rotational speed n of second motors2, so as to adjust
First motor and the second motor actual speed n, | ns1- n |=| n-ns2|。
3. AC variable-frequency speed regulation system according to claim 1 and 2, it is characterised in that described whole
Also include DC filtering unit between stream unit and first inversion unit and second inversion unit,
The DC filtering unit is used to filter the AC compounent in the DC power supply.
4. AC variable-frequency speed regulation system according to claim 1 and 2, it is characterised in that described
Direct current common bus connection between one inversion unit and second inversion unit；
When first motor is in power supply state, second motor is in generating state, described the
It is inverse that the electric energy that two motors are produced is delivered to described first by second inversion unit and the dc bus
Become unit；
When second motor is in power supply state, first motor is in generating state, described the
It is inverse that the electric energy that one motor is produced is delivered to described second by first inversion unit and the dc bus
Become unit.
5. AC variable-frequency speed regulation system according to claim 1 and 2, it is characterised in that described
One motor and second motor are coaxially connected by shaft coupling.
6. a kind of ac variable frequency speed regulation method, it is characterised in that be applied to AC variable-frequency speed regulation system,
The AC variable-frequency speed regulation system includes：Rectification unit, the first inversion unit, the second inversion unit,
One motor and the second motor；
The rectification unit is connected with first inversion unit and second inversion unit respectively, described
First inversion unit and first motor connection, second inversion unit and second motor connect
Connect, first motor and second motor coaxle are connected；
The rectification unit is used to for the AC driven power of input to be converted to direct current driving power supply and difference is defeated
Enter to first inversion unit and second inversion unit, first inversion unit is used for will be described
Direct current driving power supply is converted to the first AC driven power for driving first motor, second inversion
Unit is used to that the direct current driving power supply to be converted to the second exchange driving electricity for driving second motor
Source；
The ac variable frequency speed regulation method includes：
AC driven power is input into the rectification unit, so that the rectification unit drives the exchange
Dynamic Power convert is direct current driving power supply and is separately input into first inversion unit and second inversion
Unit；
By the power supply that adjusts first AC driven power and/or second AC driven power frequently
Rate adjusts the synchronous rotational speed n of first motors1And/or the synchronous rotational speed n of second motors2, from
And the actual speed n of first motor and second motor is adjusted, | ns1- n |=| n-ns2|, described
The frequency of supply of one AC driven power is f1, the frequency of supply of second AC driven power is f2,
ns1=60f1/p1, ns2=60f2/p2, first AC driven power and second AC driven power
Power supply phase sequence it is identical.
7. ac variable frequency speed regulation method according to claim 6, it is characterised in that regulation is described
The frequency of supply of the first AC driven power and/or second AC driven power, including：
The frequency of supply for adjusting first AC driven power by first inversion unit is f1, with
Adjust the synchronous rotational speed n of first motors1, so as to adjust the first motor and the second motor reality
Rotating speed n, | ns1- n |=| n-ns2|, or,
The frequency of supply for adjusting second AC driven power by second inversion unit is f2, with
Adjust the synchronous rotational speed n of second motors2, so as to adjust the first motor and the second motor reality
Rotating speed n, | ns1- n |=| n-ns2|, or,
The frequency of supply for adjusting first AC driven power by first inversion unit is f1, with
Adjust the synchronous rotational speed n of first motors1, second exchange is adjusted by second inversion unit
The frequency of supply of driving power supply is f2, to adjust the synchronous rotational speed n of second motors2, so as to adjust
First motor and the second motor actual speed n, | ns1- n |=| n-ns2|。
8. the ac variable frequency speed regulation method according to claim 6 or 7, it is characterised in that also wrap
Include：Direct current is set between the rectification unit and first inversion unit and second inversion unit
Filter unit, the DC filtering unit is used to filter the AC compounent in the DC power supply.
9. the ac variable frequency speed regulation method according to claim 6 or 7, it is characterised in that also wrap
Include：Direct current common bus connection will be carried out between first inversion unit and second inversion unit；
When first motor is in power supply state, second motor is in generating state, described the
It is inverse that the electric energy that two motors are produced is delivered to described first by second inversion unit and the dc bus
Become unit；
When second motor is in power supply state, first motor is in generating state, described the
It is inverse that the electric energy that one motor is produced is delivered to described second by first inversion unit and the dc bus
Become unit.
10. the ac variable frequency speed regulation method according to claim 6 or 7, it is characterised in that described
First inversion unit and first motor connection, including：
First motor and second motor are coaxially connected by shaft coupling.
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Cited By (1)
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| CN113472243A (en) * | 2021-06-23 | 2021-10-01 | 的卢技术有限公司 | Coaxial double-motor rotating speed synchronous control method and system |
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