The content of the invention
It is an object of the invention to provide a kind of dynamic braking method and device so that peripheral components can not increased
Under the conditions of motor can be braked, it is cost-effective;At the same time it can also be braked to motor in full rate section, practicality
By force;And retro-speed is fast, can extend electrical machinery life.
For solving above-mentioned technical problem, the invention provides a kind of dynamic braking method, comprises the steps of:
User pre-sets the control for brake pattern of converter;Wherein, the control for brake pattern is vector braking mode
Or scalar braking mode;
Judge whether default control for brake pattern is the vector braking mode;
If so, the vector braking mode is then entered, vector braking is carried out to motor;If it is not, then entering the scalar system
Dynamic model formula, carries out scalar braking to the motor.
Present invention also offers a kind of energy consuming brake, comprising:Converter;
Wherein, the converter is included:Setup module, judge module, vector brake module and scalar brake module;
The setup module, for pre-setting the control for brake pattern of converter;Wherein, the control for brake pattern is
Vector braking mode or scalar braking mode;
The judge module, for judging whether default control for brake pattern is the vector braking mode;If so, then
The vector brake module is triggered, vector braking is carried out to motor;If it is not, the scalar brake module is then triggered, to the electricity
Machine carries out scalar braking.
Embodiment of the present invention in terms of existing technologies, can not increase peripheral components, by the use of converter as energy
Consumption brake unit, is braked to motor, so that having saved cost;And, user can pre-set the system of converter
Dynamic control model, wherein, control for brake pattern is vector braking mode or scalar braking mode;Either vector braking mode
Or scalar braking mode, motor all export portion of energy to energy consuming brake, and energy consuming brake is disappeared jointly with motor
, up to the braking to motor is completed, the retro-speed than individually being carried out energy expenditure by motor is fast for energy consumption, and by dynamic braking
Device consumes portion of energy, it is possible to reduce the energy of electrical consumption, extends the life-span of motor;Meanwhile, energy consuming brake is also
Motor can be braked in full rate section, improve the practicality of energy consuming brake.So, the present invention can not increase
Plus motor can be braked under conditions of peripheral components, it is cost-effective;At the same time it can also carry out to motor in full rate section
Braking, it is practical, and retro-speed is fast, can extend the life-span of motor.
In addition, described into the vector braking mode, in carrying out the step of vector is braked to motor, comprising following son
Step:
Feedback quantity by braking moment controller according to the target control physical quantity for pre-setting with the physical quantity is closed
Ring computing, and generate output plugging torque;
Amplitude limit is carried out to the output plugging torque by torque amplitude limit controller, and generates torque current Iqref;
By torque current controller according to the IqrefGenerate q axle output voltage Uq;Wherein, the q axles are torque current
Synchronous rotary axle;
By exciting current controller according to the IqrefDynamic adjustment exciting current simultaneously produces maximum output exciting current
Idref;
By field current controller according to the IdrefGenerate d axle output voltage Ud;Wherein, the d axles are magnetic linkage electric current
Synchronous rotary axle;
The rotating speed SPD of motor by described in encoder real-time monitoringfdbAnd calculate electrical angle θ;Or by pre- in real time without fast sensor
Estimate the rotating speed SPD of the motorfdbAnd calculate the electrical angle;
Vector calculus is carried out according to the Uq, the Ud and the θ by pulse-width modulator PWM and generates three-phase voltage,
Vector braking is carried out to the motor.
As exciting current controller dynamic adjusts exciting current and produces the output exciting current Id of maximumrefSo that electricity
Electromechanical stream reaches maximum, while to a certain degree increasing the harmonic wave of electric current, makes motor consumed energy to a greater degree, further plus
Braking of the speed to motor.
In addition, before the step of user pre-sets the control for brake pattern of converter, also comprising the steps of:
Switch to default modulating mode.In addition, the modulating mode is seven segmentation modulating modes.Due to each switch of seven segmentation patterns
Device all can be switched once in switch periods, so can consumed energy to a greater degree, it is possible to further plus
Braking of the speed to motor.
In addition, it is described switch to default modulating mode the step of before, also comprise the steps of:Lift the frequency conversion
The switching frequency of device.The switching frequency of converter is lifted, MOS switch dissipation will become big, as such, it is possible to disappear to a greater degree
Energy consumption, it is possible to further speed up the braking to motor.
Specific embodiment
For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with each reality of the accompanying drawing to the present invention
The mode of applying is explained in detail.However, it will be understood by those skilled in the art that in each embodiment of the invention,
In order that reader more fully understands the application and proposes many ins and outs.But, even if there is no these ins and outs and base
In many variations and the modification of following embodiment, it is also possible to realize each claim of the application technical side required for protection
Case.
The first embodiment of the present invention is related to a kind of dynamic braking method, and idiographic flow is as shown in figure 1, include following step
Suddenly:
Step 101, user pre-set the control for brake pattern of converter.Wherein, control for brake pattern is braked for vector
Pattern or scalar braking mode.Specifically, in the present embodiment, using converter as energy consuming brake, it is not necessary to
Increase ancillary equipment, and converter includes two kinds to the control for brake pattern of motor, respectively vector braking mode and scalar
Braking mode.In practical application, user's (user) selects suitable control for brake pattern and pre-sets.So, may be used
To be braked to motor in full rate section, the practicality of dynamic braking method is improved.
Step 102, judges whether default control for brake pattern is vector braking mode.If so, then execution step 103;
If it is not, then execution step 104.
Step 103, into vector braking mode, carries out vector braking to motor.When default control for brake pattern is arrow
During amount braking mode, just into vector braking mode, vector braking is carried out to motor.When vector braking is carried out, by converter
Built-in pulse-width modulator (PWM) is entered with electrical angle (θ) to q axle output voltages (Uq), d axle output voltages (Ud) that obtain
Row vector calculus simultaneously generates three-phase voltage, and motor is controlled.Wherein, synchronous rotary axle of the q axles for torque current, d axles are
Magnetic linkage current synchronization rotary shaft.In vector braking procedure, motor exports portion of energy to converter, and converter is with motor altogether
Same consumed energy, until complete the braking to motor.So, it is faster than individually being carried out the retro-speed of energy expenditure by motor;And
Portion of energy is consumed by energy consuming brake, it is possible to reduce the energy of electrical consumption, extend the life-span of motor.
Step 104, into scalar braking mode, carries out scalar braking to motor.When default control for brake pattern is not
During vector braking mode, just into scalar braking mode, scalar braking is carried out to motor.When scalar braking is carried out, by frequency conversion
The built-in pulse-width modulator of device (PWM) carries out scalar operation to the current speed of service (f (k)) for obtaining with modulation degree (m)
And three-phase voltage is generated, motor is controlled.In scalar braking procedure, motor is also exported portion of energy to converter,
Converter and the common consumed energy of motor, until complete the braking to motor.So, than individually carrying out energy expenditure by motor
Retro-speed is fast;And portion of energy is consumed by energy consuming brake, it is possible to reduce and the energy of electrical consumption, extend the longevity of motor
Life.
It is noted that in the present embodiment, a kind of method of control braking, idiographic flow such as Fig. 2 institutes are further related to
Show, comprise the steps of:
Step 201, switch of cutting off the electricity supply.The power supply is electric machine with energy, can be utility grid.Cut off in braking
On and off switch, can avoid electrical network input energy.
Step 202, into braking mode.In this step, comprising sub-steps such as step 101~104.
Step 203, judges whether to complete braking.If so, then execution step 204;If it is not, then execution step 202, until electricity
The speed of machine is 0 or less than the speed of setting.When the speed of motor be 0 or less than setting speed when, complete braking procedure.
Step 204, exits braking mode.
On and off switch is initially switched off before to motor braking, and electrical network input energy can be avoided to affect braking.
Compared with prior art, peripheral components can not be increased, by the use of converter as energy consuming brake, motor is entered
Row braking, so that saved cost;And, user can pre-set the control for brake pattern of converter, either swear
Amount braking mode or scalar braking mode, motor all export portion of energy to energy consuming brake, energy consuming brake and
, up to the braking to motor is completed, the retro-speed than individually being carried out energy expenditure by motor is fast for the common consumed energy of motor, and
Portion of energy is consumed by energy consuming brake, it is possible to reduce the energy of electrical consumption, extend the life-span of motor;Meanwhile, energy consumption
Brake unit can improve the practicality of energy consuming brake to be braked to motor in full rate section.
Second embodiment of the present invention is related to a kind of dynamic braking method, and idiographic flow is as shown in Figure 3.Second embodiment party
Formula has been made further to improve on the basis of first embodiment, mainly thes improvement is that:In second embodiment of the invention
In, the switching frequency of converter, and the bigger modulating mode of service wear is first lifted, motor more consumed energy is made, is entered
One step accelerates the braking to motor.
Specifically, in the present embodiment, comprise the steps of:
Step 301, lifts the switching frequency of converter.Wherein, the switch of converter can be turned on certain frequency or be closed
It is disconnected.By lifting the switching frequency of converter, MOS switch dissipation will become big, as such, it is possible to consumed energy to a greater degree
(this is determined by switching device (such as IGBT (insulated gate bipolar transistor) etc.)), it is possible to further speed up to electricity
The braking of machine.
Step 302, switches to default modulating mode.In the present embodiment, modulating mode can be modulated for seven segmentations
Pattern.According to the brake request to motor, select suitable modulating mode and switch to the modulating mode for pre-setting, such as
Say, default modulating mode is seven segmentation modulating modes, as seven each switching device of segmentation pattern are in switch periods
Will switch once (and the modulation of some debugging modes, such as five-part form, there are two switching devices<Upper and lower bridge>In switch periods
Inside it is failure to actuate, thus, switching device power consumption will be reduced), as such, it is possible to consumed energy to a greater degree, so
The braking to motor can be further speeded up.
It should be noted that different modulating pattern can allow switching device to have different on-off times in switch periods
And service time, according to switching device (such as IGBT) characteristic, on-off times are more, service time is longer, allow for switching device
Radiating is bigger.
Step 303, user pre-set the control for brake pattern of converter.Step in this step and first embodiment
101 are similar to, and will not be described here.
Step 304, judges whether default control for brake pattern is vector braking mode.If so, then execution step 305;
If it is not, then execution step 306.
Step 305, into vector braking mode, carries out vector braking to motor.In this step and first embodiment
Step 103 is similar to, and will not be described here.
Step 306, performs scalar braking mode, carries out scalar braking to motor.In this step and first embodiment
Step 104 is similar to, and will not be described here.
In the present embodiment, the switching frequency of converter is lifted, and default modulating mode is switched to (as 7 segmentations are adjusted
Die trial formula) can consumed energy to a greater degree, further speed up the braking to motor.
Third embodiment of the invention is related to a kind of dynamic braking method.3rd embodiment enters for first embodiment
Step refining, gives specific dynamic braking method.In third embodiment of the present invention, vector braking mode is given
Concrete grammar, idiographic flow is as shown in Figure 4, it is ensured that the feasibility of embodiment of the present invention.
In the present embodiment, illustrate by taking the system structure shown in Fig. 5 as an example.Wherein, K1 is on and off switch, can be with
Control manually, system can not be controlled;The input voltage of converter is 380V, and uncontrollable rectification correspondence busbar voltage is 540V, when
Busbar voltage is more than carrying out overvoltage protection during 800V.
Specifically, vector braking mode is comprised the steps of:
Step 401, by braking moment controller according to the feedback of the target control physical quantity that pre-sets and the physical quantity
Amount carries out closed loop computing, and generates output plugging torque.In the present embodiment, target control physical quantity is busbar voltage
(Udcref), bus voltage feedback amount is designated as Udcfdb.Such as, it is 700V that can pre-set target control busbar voltage, to work as
Feedback quantity of the front bus voltage value as braking moment controller, carries out closed loop computing and produces output plugging torque
(Troq)。
Step 402, carries out amplitude limit by torque amplitude limit controller to exporting plugging torque, and generates torque current
(Iqref).The output plugging torque (referred to as, output torque) that braking moment controller is exported by torque amplitude limit controller is entered
Row amplitude limiting processing, determines torque current (Iqref) (i.e. equivalent output torque) export to torque current controller.Wherein, torque
Amplitude limiting controller determines maximum output plugging torque, when braking moment controller according to technique, requirement and frame for movement
When the output plugging torque of requirement exceedes the maximum output plugging torque for allowing, with regard to the increase of torque-limiting, to produce
The raw maximum output plugging torque for allowing.
Step 403, by torque current controller according to IqrefGenerate q axle output voltages (Uq);Wherein, q axles are torque electricity
The synchronous rotary axle of stream.
Step 404, by exciting current controller according to IqrefDynamic adjustment exciting current simultaneously produces maximum output excitation
Electric current (Idref).Exciting current controller is according to output torque (or Iqref) dynamic adjustment exciting current, reached with this defeated
Go out the purpose of maximum current, wherein,IesFor user for default DC injection braking when output electricity
Stream, is usually no more than converter (or motor) rated current (consideration of the restriction primarily for safe failure-free operation), and Ies gets over
Big power consumption is bigger.In addition, exciting current controller can prevent magnetic saturation or underexcitation per se with the amplitude limit up and down of exciting current
Magnetic.
As exciting current controller can adjust exciting current with dynamic and produce the output exciting current (Id of maximumref),
So that current of electric reaches maximum, while to a certain degree increasing the harmonic wave of electric current, motor is allow to consume energy to a greater degree
Amount, has further speeded up the braking to motor.
Step 405, by field current controller according to IdrefGenerate d axle output voltages (Ud);Wherein, d axles are magnetic linkage electricity
Stream synchronous rotary axle.
Step 406, by the rotating speed (SPD of encoder real-time monitoring motorfdb) and calculate electrical angle (θ).Or, by without speed
Sensor estimates the rotating speed SPD of motor in real timefdbAnd calculate electrical angle.
Step 407, carries out vector calculus by pulse-width modulator (PWM) according to Uq, Ud and θ and generates three-phase voltage, right
Motor carries out vector braking.Vector calculus in present embodiment is consistent with conventional vector computing, will not be described here.
So far, the introduction of vector braking mode is finished.
It should be noted that in the present embodiment, also comprise the steps of:By the built-in current converter of converter
(abc-dq) sample rate current Ia, Ib, Ic of motor are transformed to into current exciting current IdfdbWith current torque electric current Iqfdb, and point
Field current controller and torque current controller are not fed back to.This coordinate transform is the basis of vector controlled, because vector
The theoretical foundation of control is that alternating current generator is decoupled into direct current generator, so just has exciting current and torque current two is mutual
Vertical amount, which intuitively can be embodied in dq coordinate systems.
It is noted that the system structure shown in Fig. 5 is a kind of specific implementation, in actual applications, may be used also
With using the system with bypass functionality shown in Fig. 6.In many application of frequency converter occasions, when event occurs in operating converter
When barrier or other special circumstances, in order to not affect normal operation flow process, need for motor to switch to operation under power frequency state.As worked as
After operating converter breaks down, disconnect and switch K1, K2, the time delay a bit of time, after waiting counter electromotive force of motor to disappear, then
K3 is connected into, so as to realize that automatic system is bypassed.Wherein, K1, K2, K3 are switching devices, such as vacuum contactor etc., and the device can be with
It is that control, or system are automatically controlled manually.
Four embodiment of the invention is related to a kind of dynamic braking method.4th embodiment enters for first embodiment
Step refining, gives specific dynamic braking method.In the 4th embodiment of the present invention, scalar braking mode is given
Concrete grammar, idiographic flow is as shown in Figure 7, it is ensured that the feasibility of embodiment of the present invention.
In the present embodiment, equally illustrate by taking the system structure shown in Fig. 5 as an example.The input voltage of converter is
380V, uncontrollable rectification correspondence busbar voltage is 540V, carries out overvoltage protection when busbar voltage is more than 800V.
Specifically, scalar braking mode is comprised the steps of:
Step 701, by acceleration closed loop controller according to the first object control physical quantity and the physical quantity for pre-setting
Feedback quantity carry out feedback op, and generate acceleration (a).Wherein, first object controls physical quantity for busbar voltage
(Udcref), the feedback quantity of busbar voltage is designated as Udcfdb;Acceleration (a) is negative value herein, it is understood that for deceleration time.Than
As said, it is 700V that can preset target control busbar voltage, using current bus voltage value as acceleration closed loop controller
Feedback quantity, carry out closed loop computing, and export acceleration (or deceleration time).Wherein, busbar voltage requires more than converter
The voltage peak (net side line voltage peak value) of uncontrollable rectifier bridge output when unloaded, and in the model that can be born in bus capacitor
In enclosing.
Step 702, calculates current time rotating speed (f according to upper moment rotating speed (f (k-1)) with a by velocity calculator
(k)).Wherein, rotating speed can also be frequency.Specifically, the acceleration that velocity calculator is exported according to acceleration closed loop controller
Degree (or deceleration time), with reference to previous moment rotating speed (f (k-1)) (or frequency), calculate current the speed of service (f (k)) (or
Person's frequency), in this, as the rotating speed (or frequency) needed for scalar braking.
Step 703, by closed-loop current control device according to the second target control physical quantity and the physical quantity for pre-setting
Value of feedback carries out closed loop computing, generates modulation degree (m).Wherein, the second target control physical quantity is the output of current converter
Current effective value (Iref), the feedback quantity of output current virtual value is designated as Ifdb.Specifically, preset closed-loop current control device
Target output current be 96% Rated motor electric current, using current output current of frequency converter virtual value as closed-loop current control
The feedback quantity of device, carries out closed loop computing, and exports the modulation degree (m) needed for scalar braking.
Step 704, carries out scalar operation by pulse-width modulator (PWM) according to m and f (k) and generates three-phase voltage, to electricity
Machine carries out scalar braking.PWM is according to modulation degree (m) and current rotating speed (f (k)) (or frequency), the three-phase voltage needed for generating
(Uu, Uv, Uw), carries out scalar braking to motor.
So far, the introduction of scalar braking mode is finished.
In scalar braking mode, first, by adjust deceleration-based controller busbar voltage, it is to avoid in moderating process electrical network after
Continue toward converter and motor conveying energy;Secondly, by adjusting modulation degree (m) so that the electric current of output is as big as possible, then can be more
The heating of copper loss, iron loss and switching device that big degree increases motor (is determined by motor characteristic, is briefly I2R, its
In, I is electric current, and R is the equivalent resistance of motor), so under scalar braking mode, this method can more accelerate motor kinetic energy
Loss (change into electric energy (rising of bus capacitor voltage), (the motor feels hot, converter MOS switch dissipation to change into heat energy
Deng)), to reach the effect faster braked.
Above the step of various methods divide, be intended merely to description it is clear, can merge into when realizing a step or
Some steps are split, multiple steps are decomposed into, as long as comprising identical logical relation, all in the protection domain of this patent
It is interior;To adding inessential modification in algorithm or in flow process or introducing inessential design, but its algorithm is not changed
With the core design of flow process all in the protection domain of the patent.
5th embodiment of the present invention is related to a kind of energy consuming brake, comprising:Converter;Wherein, converter is included:
Setup module, judge module, vector brake module and scalar brake module, it is concrete as shown in Figure 8.
Setup module, for pre-setting the control for brake pattern of converter;Wherein, control for brake pattern is braked for vector
Pattern or scalar braking mode.
Judge module, for judging whether default control for brake pattern is vector braking mode;If so, then trigger vector
Brake module, carries out vector braking to motor;If it is not, then triggering scalar brake module, scalar braking is carried out to motor.
It is seen that, present embodiment is the system embodiment corresponding with first embodiment, and present embodiment can be with
First embodiment is worked in coordination enforcement.The relevant technical details mentioned in first embodiment still have in the present embodiment
Effect, in order to reduce repetition, is repeated no more here.Correspondingly, the relevant technical details mentioned in present embodiment are also applicable in
In first embodiment.
6th embodiment of the present invention is related to a kind of energy consuming brake, and concrete structure is as shown in Figure 9.6th embodiment party
Formula on the basis of the 5th embodiment has been made further to improve, and mainly thes improvement is that, in sixth embodiment of the invention
In, also include:Switching frequency hoisting module and modulating mode handover module, make motor more consumed energy, further plus
Braking of the speed to motor.
Specifically, switching frequency hoisting module, for lifting the switching frequency of converter.
Modulating mode handover module, for switching to default modulating mode.Wherein, modulating mode is that seven segmentations modulate mould
Formula.
As second embodiment is mutually corresponding with present embodiment, therefore present embodiment can be mutual with second embodiment
It is engaged enforcement.The relevant technical details mentioned in second embodiment still effectively, are implemented second in the present embodiment
The technique effect that can be reached in mode is in the present embodiment similarly it is achieved that in order to reduce repetition, no longer go to live in the household of one's in-laws on getting married here
State.Correspondingly, the relevant technical details mentioned in present embodiment are also applicable in second embodiment.
Seventh embodiment of the invention is related to a kind of energy consuming brake.7th embodiment is entering for the 5th embodiment
Step refining, gives the concrete structure of vector brake module, as shown in Figure 10, it is ensured that embodiment of the present invention it is feasible
Property.
Specifically, vector brake module is included:Braking moment controller, torque amplitude limit controller, torque current control
Device, exciting current controller, field current controller, encoder or without fast sensor and pulse-width modulator.
Braking moment controller, for carrying out with the feedback quantity of the physical quantity according to the target control physical quantity for pre-setting
Closed loop computing, and generate output plugging torque.
Torque amplitude limit controller, for carrying out amplitude limit to exporting plugging torque, and generates torque current (Iqref)。
Torque current controller, for according to IqrefGenerate q axle output voltages (Uq);Wherein, q axles are the same of torque current
Step rotary shaft.
Exciting current controller, for according to IqrefDynamic adjustment exciting current simultaneously produces maximum output exciting current
(Idref)。
Field current controller, for according to IdrefGenerate d axle output voltages (Ud);Wherein, d axles are magnetic linkage current synchronization
Rotary shaft.
Encoder, for the rotating speed (SPD of real-time monitoring motorfdb) and calculate electrical angle (θ).Or, without fast sensor,
For estimating the rotating speed SPD of motor in real timefdbAnd calculate electrical angle.
Pulse-width modulator (PWM), generates three-phase voltage for carrying out vector calculus according to Uq, Ud and θ, motor is entered
Row vector is braked.
As the 3rd embodiment is mutually corresponding with present embodiment, therefore present embodiment can be mutual with the 3rd embodiment
It is engaged enforcement.The relevant technical details mentioned in 3rd embodiment still effectively, are implemented the 3rd in the present embodiment
The technique effect that can be reached in mode is in the present embodiment similarly it is achieved that in order to reduce repetition, no longer go to live in the household of one's in-laws on getting married here
State.Correspondingly, the relevant technical details mentioned in present embodiment are also applicable in the 3rd embodiment.
Eighth embodiment of the invention is related to a kind of energy consuming brake.8th embodiment is entering for the 5th embodiment
Step refining, gives the concrete structure of scalar brake module, as shown in figure 11, it is ensured that embodiment of the present invention it is feasible
Property.
Specifically, scalar brake module is included:Acceleration closed loop controller, velocity calculator, closed-loop current control device
With pulse-width modulator.
Acceleration closed loop controller, for the feedback according to the first object control physical quantity and the physical quantity for pre-setting
Amount carries out feedback op, and generates acceleration (a).
Velocity calculator, for calculating current time rotating speed (f (k)) according to upper moment rotating speed (f (k-1)) with a.
Closed-loop current control device, for the value of feedback according to the second target control physical quantity and the physical quantity for pre-setting
Closed loop computing is carried out, modulation degree (m) is generated.
Pulse-width modulator (PWM), generates three-phase voltage for carrying out scalar operation according to m and f (k), motor is entered
Rower amount is braked.
As the 4th embodiment is mutually corresponding with present embodiment, therefore present embodiment can be mutual with the 4th embodiment
It is engaged enforcement.The relevant technical details mentioned in 4th embodiment still effectively, are implemented the 4th in the present embodiment
The technique effect that can be reached in mode is in the present embodiment similarly it is achieved that in order to reduce repetition, no longer go to live in the household of one's in-laws on getting married here
State.Correspondingly, the relevant technical details mentioned in present embodiment are also applicable in the 4th embodiment.
It will be understood by those skilled in the art that the respective embodiments described above are to realize the specific embodiment of the present invention,
And in actual applications, can to which, various changes can be made in the form and details, without departing from the spirit and scope of the present invention.