CN109804549A - Motor drive and the freezer for using it - Google Patents
Motor drive and the freezer for using it Download PDFInfo
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- CN109804549A CN109804549A CN201780061436.3A CN201780061436A CN109804549A CN 109804549 A CN109804549 A CN 109804549A CN 201780061436 A CN201780061436 A CN 201780061436A CN 109804549 A CN109804549 A CN 109804549A
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- motor
- pwm
- brushless
- time
- waveform
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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
- H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
- H02P6/14—Electronic commutators
- H02P6/16—Circuit arrangements for detecting position
- H02P6/18—Circuit arrangements for detecting position without separate position detecting elements
- H02P6/182—Circuit arrangements for detecting position without separate position detecting elements using back-emf in windings
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- Power Engineering (AREA)
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
Motor drive (12) includes: waveform generating unit (10), using PWM generate conduction angle be 120 degree of rectangular waves below or with its comparable waveform；With driving portion (11), with the waveform output drive signal generated by waveform generating unit (10), thus starting brushless DC motor (5).
Description
Technical field
This disclosure relates to drive the motor drive of brushless DC motor and the freezer using it.
Background technique
In the prior art, in such motor drive, with PWM, (Pulse Width Modulation, pulse are wide
Degree modulation) it controls and carrys out drive motor.In PWM control, the application voltage to motor is controlled with the conducting width of PWM, because
This, the lower PWM conducting ratio of rotation speed (hereinafter, when except illustrating, being only called speed) of current motor is lower, speed
It is higher to spend higher PWM conducting ratio.
In addition, the rotation speed of motor is minimum in the starting of motor, therefore, the conducting ratio of PWM is extremely low, PWM
Turn-on time shorten.Since the turn-on time of PWM shortens, so terminal voltage is disconnected before rising, causing cannot be correct
Ground carries out position detection.Therefore, in order to ensure the turn-on time of PWM, take reduce PWM cycle etc. countermeasure (for example, referring to
Patent document 1).
In addition, position error detection occurs, therefore, generally exists if detecting the ring generated in terminal voltage conducting
Position detection is carried out after ring convergence.However, the turn-on time of PWM is short when motor starting, front terminal voltage is restrained in ring
Disconnect.Therefore, the countermeasure of threshold value for only changing position detection in the starting of motor etc. is also taken (for example, patent is literary
It offers 2).
Fig. 6 is existing motor drive documented by patent document 1.As shown in fig. 6, existing motor drive
Device 100 includes: brushless DC motor 101, by the inversion for driving the multiple switch element of brushless DC motor 101 to constitute
Device 102 carries out the driving portion 103 of PWM control to the switch of inverter 102 and judges whether brushless DC motor 101 is starting
In and judging result is input to the starting judging part 104 of driving portion 103.
Driving portion 103 will be used to drive the multiple switch element conductive of the inverter 102 of brushless DC motor 101 and break
It opens.In addition, driving portion 103 changes turn-on time by PWM control, to control the revolving speed of brushless DC motor 101.It rises
Dynamic judging part 104 judges whether brushless DC motor 101 is and judging result to be input to driving portion 103 in starting.It is driving
Portion 103 makes PWM carrier frequency lower than the PWM carrier frequency in common operating when brushless DC motor 101 is in starting.
In addition, being sufficient for position accelerating to the rotation speed of brushless DC motor 101 in driving portion 103 with low PWM carrier frequency
After setting the state of detection, it is switched to common operating, PWM carrier frequency is set as middle high compared with dynamic.
The conducting width of PWM becomes larger as a result, and when driving the switch element of inverter 102, pulse sufficiently rises.Therefore,
The peak value of the induced voltage of brushless DC motor becomes the level of script, can certainly carry out in the starting of brushless DC motor
Rotor position detection.
But existing structure shown in patent document 1 declines PWM carrier frequency in the starting of brushless DC motor,
Turn-off time width is elongated.It is elongated during the position of magnetic pole of brushless DC motor can not be detected as a result, therefore position detection essence
Degree decline, causes startability to deteriorate.In addition, PWM carrier wave can not be freely selected in the existing structure shown in patent document 1
Frequency, accordingly, there exist noise etc. is led to the problem of due to resonance.
In addition, the peak value of ring is influenced by current value in the existing structure shown in patent document 2, and therefore, ring
Peak value can according to start when load size and change.Load freezer not necessarily at the start is so as a result,
System in, there are the position detection moment can according to start when load and to deviate, it is difficult to the problem of steadily starting.
Existing technical literature
Patent document
Patent document 1: Japanese Unexamined Patent Publication 8-223971 bulletin
Patent document 2: Japanese Unexamined Patent Publication 2003-111482 bulletin
Summary of the invention
The disclosure is completed in view of existing problem as described above, is provided even if changing big shape in load torque
Under state, the motor drive that also can steadily start.
Specifically, including waveform generating unit and drive according to the motor drive of an example of embodiment of the present disclosure
Dynamic portion.Waveform generating unit utilizes PWM to generate conduction angle (ohmic heatingp) for 120 degree of rectangular waves below or with it
Standard) waveform.Driving portion starts brushless DC motor according to the waveform output drive signal generated by waveform generating unit.
According to this structure, even if identical PWM carrier frequency, the conducting width of PWM can also be extended.Therefore, i.e.,
Make to be the conducting width that can not carry out PWM relatively narrow as position detection with 120 degree of step modes, it also can be usually to operate
Used carrier frequency carries out position detection, can be realized the starting of stable motor.
In addition, according to this structure, the period of ring is determined by motor or circuit impedance, convergence time centainly without
It can not be changed according to load.Therefore, width is connected by extending PWM with identical PWM carrier frequency, it can be ensured that receive to ring
Time until holding back.Therefore, according to this structure, stable motor can not be realized by the size loaded with being influenced
Driving.
In addition, in the motor drive according to an example of embodiment of the present disclosure, waveform generating unit can also be with
It constitutes as follows, it may be assumed that needed for the detection for the position of magnetic pole that cannot ensure brushless DC motor when conducting width, output
Conduction angle be rectangular wave less than 120 degree or with its comparable waveform.According to this structure, it is typically without special countermeasure
It can start, in the abnormality that the PWM conducting width that input voltage is got higher etc. narrows etc, it can be ensured that needed for position detection
PWM be connected width.It can be realized the driving of stable motor when abnormal as a result,.
In addition, according to the motor drive of an example of embodiment of the present disclosure can also further include be assembled with it is brushless
The compressor of DC motor.At this point, the load for acting brushless DC motor can be the compression element of compressor.According in this way
Structure, even width is connected in load starting very light, PWM needed for can also ensure that position detection.As a result, according to this
The structure of sample, the compressor of load not necessarily when can make to start steadily start.
In addition, the disclosure provides the freezer of any one including above-mentioned motor drive.Including above-mentioned motor
Any one freezer of driving device also may include the refrigeration for being sequentially connected compressor, condenser, pressure reducer and evaporator
Circulation.According to this structure, even if the load of freezer is light, application voltage needed for the starting of brushless DC motor is small,
Width is connected in PWM needed for capable of ensuring position detection, even if also can under the conditions of the ambient temperature of freezer low temperature
Realize the starting of stable motor.
Detailed description of the invention
Fig. 1 is the block diagram according to the motor drive of an example of embodiment of the present disclosure.
Fig. 2 is the terminal electricity indicated according to the load of the brushless DC motor 5 of an example of embodiment of the present disclosure when light
The figure of the waveform (B) of terminal voltage when the load of the waveform (A) and brushless DC motor 5 of pressure is heavy.
Fig. 3 is the general brushless DC for indicating to switch the motor drive of an example according to embodiment of the present disclosure
The waveform (A) of switch element when the starting of motor, and switch drive according to the motor of an example of embodiment of the present disclosure
The figure of the waveform (B) of switch element when the starting of dynamic device.
Fig. 4 be it is in the motor drive indicated according to an example of embodiment of the present disclosure, in brushless DC electric
When the starting of machine and usual, change the flow chart of the motion flow of the waveform generating unit of PWM turn-on time and conduction angle.
Fig. 5 is minimum in the motor drive indicated according to an example of embodiment of the present disclosure, to ensure PWM
The flow chart of the motion flow of the waveform generating unit of turn-on time.
Fig. 6 is the block diagram of existing motor drive.
Specific embodiment
Hereinafter, being illustrated referring to example of the attached drawing to embodiment of the present disclosure.In addition, and non-used implementation below
Mode limits the invention.
(embodiment)
Fig. 1 is the block diagram according to the motor drive of an example of embodiment of the present disclosure.
In Fig. 1, AC power source 1 is general power frequency supply, such as in the 50Hz or 60Hz that Japan is virtual value 100V
Power supply.
As shown in Figure 1, according to the motor drive 12 of an example of embodiment of the present disclosure by rectification circuit 2, flat
Cunning portion 3, position detection part 6, speed detecting portion 7, applies voltage determination section 8, voltage detection department 9, waveform generating unit at inverter 4
10 and driving portion 11 constitute.Motor drive 12 is connect with AC power source 1, is driven to brushless DC motor 5.
Rectification circuit 2 is the component that AC power source 1 is become AC power rectification as input to direct current power, by bridge
The 4 rectifier diode 2a~2d connect are constituted.
Partes glabra 3 is connect with the outlet side of rectification circuit 2, makes the output smoothing of rectification circuit 2.In the present embodiment,
Partes glabra 3 is made of smoothing capacity device or reactor.In the present embodiment, in order to simplify circuit structure, partes glabra 3 is shown
The example being only made of smoothing capacity device.
In addition, be inserted between AC power source 1 and capacitor in the case where partes glabra 3 has used reactor,
The which side of the front and back of rectifier diode 2a~2d is set.In addition, constituting being total to for high frequency removing unit about reactor
In the case that mode filter is set to circuit, the synthetic ingredient with the reactive component of high frequency removing unit can be considered.
Direct current power from partes glabra 3 is converted to AC power by inverter 4.Inverter 4 by 6 switch element 4a~
4f is constituted with three phase bridge.In addition, 6 back flow current diode 4g~4l and switch element 4a~4f inversely connects respectively
It connects.
Brushless DC motor 5 is made of the rotor 5a with permanent magnet and the stator 5b with three-phase windings.In brushless DC
In motor 5, the three-phase alternating current by being formed by inverter 4 rotates rotor 5a in the three-phase windings flowing of stator 5b.
Position detection part 6 is according to the induced voltage of the three-phase windings generation in stator 5b and in the three-phase windings of stator 5b
Electric current and application voltage of flowing etc., to detect the position of magnetic pole of rotor 5a.In the present embodiment, position detection part 6 obtains
The terminal voltage of brushless DC motor 5 detects the magnetic pole relative position of the rotor 5a of brushless DC motor 5.Specifically, position
Induced voltage of the test section 6 based on the three-phase windings generation in stator 5b, detects the relatively rotation place of rotor 5a.It is more specific and
Speech, is compared induced voltage and the voltage as benchmark, detects zero crossing.The benchmark of zero crossing as induced voltage
Both virtual midpoint can be arranged according to the terminal voltage of three-phase in voltage, can also obtain DC bus-bar voltage as the voltage.
In the present embodiment, using virtual midpoint as the voltage of the benchmark for the zero crossing for becoming induced voltage.According to induced voltage into
Row detection mode can structure constitute simple and inexpensively.
The current rotation for the positional information calculation brushless DC motor 5 that speed detecting portion 7 is detected according to position detection part 6
Rotary speed and in the past 1 turn of average speed.In the present embodiment, when the passing through of zero cross detection of inductance voltage is measured
Between, it is calculated from this by the time to the interval of induced voltage zero crossing as section by the time.According to newest area
Between by the time calculate brushless DC motor 5 current rotation speed.In addition, speed detecting portion 7 calculates section when passing through
Between the sum of 1 turn of past, 1 turn of average speed is calculated according to the result.
Apply voltage determination section 8 to 1 turn of the average speed detected by speed detecting portion 7 and from externally input target
Speed is compared.If the average speed that 1 turn of target speed ratio is high, applies voltage determination section 8 and determine to improve to brushless DC
The application voltage of motor 5, and by determined application voltage input to waveform generating unit 10.If 1 turn of target speed ratio
Average speed is low, then applies voltage determination section 8 and determine to reduce the voltage for applying brushless DC motor 5, and apply determined
Making alive is input to waveform generating unit 10.If target velocity is consistent with 1 turn of average speed, applies voltage determination section 8 and determine
Maintain the voltage applied to brushless DC motor 5 calmly, and by determined application voltage input to waveform generating unit 10.
Voltage detection department 9 detects the value for being smoothed by partes glabra 3 and being input to the DC bus-bar voltage of inverter 4.As
The value obtained by after the high resistance decompression of impedance, the method etc. that original value is obtained according to intrinsic standoff ratio can be used in the method for detection.
This method is using pressure resistance effective when usually 5V microcomputer below (microcomputer) detects voltage, and can be inexpensive
Ground is constituted.In addition, to make an uproar as removal in input line capacitor etc. being inserted near the microcomputer of detection DC bus-bar voltage
The filter of sound.The capacitor of filter selects capacitor of the electrostatic capacitance for tens of pF to tens of μ F.It is flat needing to remove
When the ripple component in cunning portion 3, the capacitor for selecting electrostatic capacitance big, when needing the accurate voltage value comprising pulsation, selection
The small capacitor of electrostatic capacitance.In the present embodiment, in order to accurately control the voltage applied to brushless DC motor 5,
Using the structure for the noise filter for carrying out dividing and using 100pF by resistance.Thereby, it is possible to high with very inexpensive structure
Detect voltage to precision.
Waveform generating unit 10 is detected according to the application voltage value determined by application voltage determination section 8 and by voltage detection department 9
D-c bus voltage value out determines the conducting ratio of PWM.The calculating of ratio is connected by being determined by application voltage determination section 8 in PWM
Fixed application voltage value is calculated divided by the d-c bus voltage value detected by voltage detection department 9.If DC bus is electric
Pressure value is certain, then it is bigger to apply the bigger PWM conducting ratio of voltage value, but when d-c bus voltage value increases, ratio is connected in PWM
Become smaller.
It is opened in addition, waveform generating unit 10 when determining electrified rate, judges whether brushless DC motor 5 is in from halted state
The state for beginning to rotate but not yet reach specified states is " when starting ".When if it is starting, waveform generating unit 10 will be common
The calculated result of ratio is connected in PWM and ratio is connected in the 2 resulting values conducts that are multiplied, wherein 2 be 120 degree divided by, 120 degree subtract
120 degree with 2 times i.e. 60 degree of obtained results of 90 degree of difference.Judgement when whether being starting can be held with the following method
Change places and judged: the current rotation speed of brushless DC motor 5 is below externally input target velocity and be regulation
Value is following when being then judged as starting, or sets up mark (flag) when starting and starting, and removing will be indicated when reaching target velocity
Deng method.In the present embodiment, waveform generating unit 10 is fast according to the current rotation of target velocity and brushless DC motor 5
Degree determines to start.In the method, it can be determined according only to the information needed for driving, therefore, the kind of information can be cut down
Class can be constituted inexpensively by reducing the RAM usage amount etc. of microcomputer etc..
Further, it in waveform generating unit 10, can determine according at the time of the position detection detected by position detection part 6
The phase for determining the energization of brushless DC motor 5 calculates switching energized phase according to by the calculated current speed of speed detecting portion 7
At the time of, switch the output of switch element 4a~4f of inverter 102.Brushless DC motor 5 is threephase motor, therefore, is led to
It is changed during the energization of electric phase with the every 60 degree of combinations of electric angle, during the energization of a phase after substantially 120 degree of energization, instead
Multiple 60 degree of disconnections.But when the starting of brushless DC motor 5, waveform generating unit 10 controls in a manner of being 90 degree during being powered
Conduction angle, during the disconnection of 90 degree of setting, wherein above-mentioned 90 degree subtract brushless DC motor 5 for 120 degree from common conduction angle
Starting when 90 degree of conduction angle of 30 degree of difference with during common disconnection 60 degree and.Switch element 4a, 4c, 4e difference are each
It is staggered 120 degree, is successively initially powered up.Switch element 4b, 4d, 4f are also the same, are respectively staggered 120 degree, are successively initially powered up.Into one
Step, switch element 4a and switch element 4b, switch element 4c and switch element 4d and switch element 4e and switch element 4f are wrong
It opens 180 degree and is initially powered up.Rotating excitation field is formed as a result, and brushless DC motor 5 rotates.
The calculated result of ratio is connected according to PWM for waveform generating unit 10 and carrier frequency determines and the energized phase of inverter 4
The time of some time and disconnection for PWM cycle being connected of corresponding switch element 4a~4f.Waveform generating unit 10 exists
When determining the PWM turn-on time and PWM turn-off time, when the time of conducting is the minimum turn-on time of pre-determined PWM,
In a manner of the minimum turn-on time for being able to maintain that PWM, during constriction is powered.
Herein, during Td indicates final energization, during Tn indicates current energization, Tp indicates the turn-on time of PWM, Tm
Indicate the minimum turn-on time of PWM.At this point, when minimum conducting of the waveform generating unit 10 with the turn-on time Tp of PWM relative to PWM
Between Tm insufficient ratio half ratio, Tn during the current energization of constriction.If being indicated with formula, for (formula 1).
(formula 1)
It is deformed, then becomes (formula 2), for example, if Tp divided by the result of Tm is 0.8, become and be in 0.8 half
It is 108 degree during energization therefore during adding the energization that 0.5 is 0.9 times on 0.4.
(formula 2)
Driving portion 11 according to the signal exported from waveform generating unit 10, make switch element 4a~4f of inverter 4 be connected or
It disconnects (hereinafter referred to as ON/OFF (ON/OFF)).
Freezer 22 carries the refrigeration cycle being made of compressor 17, condenser 19, pressure reducer 20 and evaporator 21, passes through
It will be conveyed from the air that evaporator 21 cools down to refrigerating chamber and freezing chamber, and cool down the enclosure interior of freezer 22.Compressor 17
Compress mode (linkage) the arbitrary mode such as rotary-type or Scrawl can be used.In the present embodiment, using reciprocal
The mode of type.In the compress mode of Reciprocatory, the leakage of the refrigerant as compression element is few, can under the low speed efficiently into
Row compression.In the present embodiment, compressor 17 is Reciprocatory, and therefore, rotary motion utilizes the rotor with brushless DC motor 5
The crankshaft (not shown) of 5a connection and be converted to reciprocating motion.The piston (not shown) connecting with crankshaft is past in cylinder (not shown)
It answers, thus the refrigerant in compression cylinder.
It is made of the refrigerant that compressor 17 has compressed and passes sequentially through condenser 19, pressure reducer 20 and evaporator 21 and again
Return to the refrigeration cycle of compressor 17.At this point, radiating in condenser 19, absorb heat in evaporator 21, it is thus possible into
Row cools and heats.
The motor drive 12 constituted in the above-described manner is illustrated referring to attached drawing.
Firstly, being illustrated using Fig. 2 to the decision of the minimum turn-on time of PWM.
The waveform (A) of Fig. 2 indicates the load hour of driving brushless DC motor 5, first with the switch of brushless DC motor 5
The waveform of part 4c connected terminal voltage.
The waveform (B) of Fig. 2 indicates switch member when the load of driving brushless DC motor 5 is big, with brushless DC motor 5
The waveform of part 4c connected terminal voltage.
In Fig. 2, switch element 4f is always in the conductive state, and switch element 4a is switched on when T1, switch element 4a when T3
It is disconnected.With as it does so, with the terminal voltage of the switch element 4c of brushless DC motor 5 phase being connected in T1 on induced voltage
It rises, is disconnected in T3.
But in the section from T1 to T3, induced voltage can be not only generated, rises with induced voltage in T1, can produce
Raw ring (ringing) voltage.Compared with the waveform (A) of the light Fig. 2 of the load for acting brushless DC motor 5, make brushless DC
The peak value of the ringing voltage of the waveform (B) of the Fig. 2 for the load weight that motor 5 acts is high.On the other hand, the period of ringing voltage exists
It is constant in the waveform (A) and waveform (B) of Fig. 2, it was 2 periods in the time of T2, substantially restrains together, the electricity of induced voltage itself
Pressure is shown.
Like this, comprising ring determine that the threshold value of position detection is more difficult, but for example " only to carry out position after t 2
Set detection " mode, under the influence of not by ring carry out position detection be very easy to.But for this reason, it may be necessary to leading PWM
The logical time ensures in T2 or more, therefore, it is necessary to the convergence time of measured in advance ring, is determined the minimum conducting as PWM
Time determines the minimum turn-on time as PWM.
Then, the change of the turn-on time of conduction angle and PWM is illustrated using Fig. 3.
The waveform (A) of Fig. 3 indicates the waveform of switch element 4a when switching the general starting of brushless DC motor 5.Fig. 3's
Waveform (B) indicates the waveform of switch element 4a when switching the starting of the brushless DC motor of present embodiment.
In the waveform (A) and waveform (B) of Fig. 3, horizontal axis indicates the time, and the longitudinal axis indicates the switching waveform of switch element 4a
The conducting and disconnection of state.In the waveform (A) and waveform (B) of Fig. 3, T4 is the energization start time of switch element 4a, away from T6
It has passed through and be equivalent to 120 degree of time.In the present embodiment, the time needed for position detection is P1.In the waveform (A) of Fig. 3
In, the turn-on time of PWM is the P2 shorter than P1, and the notch of the turn-on time of required PWM is P3, and position detection is unstable, no
It can be carried out the normal starting of brushless DC motor.
On the other hand, in the waveform of Fig. 3 (B), the turn-on time of PWM is set as P4, is changed in the waveform (A) of Fig. 3
2 times of turn-on time of PWM.On the other hand, it is the time of T4 to T5 during energization, is equivalent to 90 degree.For with two-phase
Energized phase, in the range of being staggered 30 degree of 60 degree, an only Xiang Tong electricity is therefore, total at 2 30 degree between 120 degree
60 degree of a range only Xiang Tong electricity does not supply electric current from inverter 4 during this period.Therefore, 90 degree during energization are for Fig. 3's
It is 120 degree during the energization of waveform (A), the section for supplying electric current is half.At 2 times of the turn-on time of PWM of conduction angle
Supply electric current multiplying power be 1/2, therefore, the average voltage during energization is maintained, target apply voltage be maintained.
In addition, PWM turn-on time needed for position detection is ensured, energy by setting 2 times for PWM turn-on time
It is enough to carry out correct position detection from the starting of the short state of PWM turn-on time, it can be realized stable starting.
Then, using Fig. 4 to change brushless DC motor 5 starting when and usually operating when PWM turn-on time and
The details of the movement of conduction angle are illustrated.
Fig. 4 is to indicate in the starting of the brushless DC motor 5 of present embodiment and when usual, changes PWM turn-on time
With the flow chart of the waveform generating unit 10 of conduction angle.
Firstly, in a step 101, the brushless DC that waveform generating unit 10 is detected according to target velocity and speed detecting portion 7
Whether the current rotation speed of motor 5 judges brushless DC motor 5 in starting.Determine in current rotation speed
When rotation speed lower than target velocity and current is such as 15r/s or less, it is determined as in starting.At this point, if target velocity
For 30r/s, the current rotation speed detected from speed detecting portion 7 is 10r/s, then is determined as in starting.Herein, if it is determined that
Result be start in (step 101 is "Yes"), proceed to step 102.
In a step 102, so that the PWM turn-on time that waveform generating unit 10 is currently about to output increases to 2 times of ground outputs
Mode to driving portion 11 is set.Later, step 103 is proceeded to.
In step 103, by during energization (during continuing energization with not switching the energized phase of brushless DC motor 5) from
Being equivalent to 120 degree of time is set as 90 degree (resulting values in half i.e. 1/4 of its 2 times inverse that 120 degree are subtracted for 120 degree)
Time, make output stopping by 90 degree of time point.Then, it is being equivalent to switching energized phase at 120 degree of time.As this
Sample exports while the phase and moment for determining output using PWM waveform as driving signal.The time for being as a result, connected PWM increases
Add, and keeps the average value of the voltage applied to 120 degree of sections of energized phase identical as before execution step 102 and step 103.
On the other hand, when being determined as that brushless DC motor 5 is not in starting in a step 101 (step 101 is "No"),
Proceed to step 104.
At step 104, driving portion 11 is output to keeping the PWM currently set conducting width with waveform generating unit 10
Mode is set, and step 105 is proceeded to.
In step 105,120 degree will be set as during energization, by every 120 degree of switchings energized phase, and using PWM waveform as
Driving signal output.
Pass through step 101~step 105 when carrying out the switching of energized phase every time more than execution, it can be ensured that position inspection
PWM needed for surveying is connected width and carries out certain starting, can be with the efficiency of brushless DC motor 5 more in usual operating
120 degree of good energizations are driven.
Then, when being unable to ensure required PWM conducting width due to variation in voltage etc. to waveform generating unit 10 using Fig. 5
Movement be illustrated.
In step 201, firstly, waveform generating unit 10, which is obtained, is input to inverter 4 by what voltage detection department 9 detected
The value of DC bus-bar voltage, proceeds to step 202.
In step 202, waveform generating unit 10 is obtained by the calculated application voltage value of application voltage determination section 8, is proceeded to
Step 203.
In step 203, with the application voltage value obtained in step 202 divided by the DC bus electricity obtained in step 201
Pressure, stores the result as the conducting ratio of PWM.Later, it is transferred to step 204.
In step 204, according to the conducting ratio of PWM calculated in step 203 and according to the speed of brushless DC motor
The pre-determined PWM carrier frequency such as range or resonance is spent, the turn-on time of PWM is set.Specifically, by the week of PWM carrier wave
The result that the conducting ratio of phase and PWM are multiplied is set as the turn-on time of PWM.Later, after the turn-on time of setting PWM, into
To step 205.
In step 205, in judgment step 204 calculated PWM turn-on time whether according to terminal voltage produce
Below the minimum turn-on time of pre-determined PWM such as the convergence time of raw ringing voltage or processing time.If PWM's leads
The logical time is shorter than the minimum turn-on time of the PWM, then cannot correctly carry out the position of magnetic pole of the rotor 5a of brushless DC motor 5
Detection, can not drive.Using the result of judgement as the turn-on time of PWM for PWM minimum turn-on time hereinafter, proceeding to step
206。
In step 206, the minimum turn-on time of the turn-on time ratio PWM of PWM is short, therefore, calculates the turn-on time of PWM
To what extent meet the ratio of the minimum turn-on time of PWM.Specifically, with the turn-on time of PWM divided by PWM most
Small turn-on time.It is stored the result being divided by as time Service Efficiency, proceeds to step 207.
In step 207, it about according to during the energization of current conduction angle and speed calculating, will be calculated in step 206
Time Service Efficiency out substitutes into (formula 2), controls driving portion 11 during the energization as final output, switches brushless DC motor
Energized phase.Later, step 208 is proceeded to.
During changing energization in a step 208, therefore, the turn-on time of PWM is changed to the minimum turn-on time of PWM,
It is output to driving portion 11.PWM by subtracting minimum turn-on time relative to PWM during being equivalent to the energization of conduction angle is led
Lead to the in shortage of time, the average application voltage in 120 degree of sections of conduction angle becomes the application electricity determined by application voltage determination section 8
Pressure value.
(step 205 when on the other hand, in step 205, more than the minimum turn-on time that the turn-on time of PWM is PWM
For "No"), proceed to step 209.
In step 209, the turn-on time of PWM does not change, and proceeds to step 210.
In step 210, it is controlled with the turn-on time of PWM that is set in step 209 with keeping intact during being powered
Driving portion 11 processed, the energized phase of the location information switching brushless DC motor 5 based on position detection part 6.
By exchanging the step 104 of Fig. 4 of above-mentioned processing with step 105, even if due to voltage in common driving
It changes etc. and PWM turn-on time shortens, can also ensure the minimum turn-on time of PWM, it can be total to common driving from starting
It is certainly to carry out position detection, realizes stable driving.
In addition, the processing of step 201~step 210 shown in fig. 5 is the place for being always to ensure that the minimum turn-on time of PWM
Reason, therefore, when being applicable not only to usually operate, when being also applied for the starting of brushless DC motor 5.Therefore, by by step 201
When the processing of~step 210 is suitable for the starting of brushless DC motor 5, it can be carried out in the starting of brushless DC motor 5 steady
Fixed position detection.In other words, the processing of the step 101 of Fig. 4~step 105 can be exchanged with step 201~step 210.By
This, does not need the processing distinguished when at the start and usually operating, and can be handled from starting to usual operating surely with same
Surely it is driven, therefore, the ROM capacity of the microcomputer for being controlled can be cut down, can be constituted inexpensively.
Then, it is illustrated to the case where being used when motor drive 12 in compressor 17.In compressor 17,
Load not necessarily, load changed according to the state of the gas of compression, therefore, brushless DC motor 5 start when, exist from
The wider range for being loaded to very heavy load very light.For load very light, applied corresponding with very heavy load
Under making alive, control is difficult to follow, so that brushless DC motor 5 can not be made successfully to start.Then, in waveform generating unit 10,
Judge that it is in the load condition of which kind of degree in 5 prestart of brushless DC motor.Determination method is to brushless DC motor
Stationary phase applies voltage, the position of fixed rotor 5a.Voltage is applied to the energized phase in the direction of the rotor 5a rotation secured.This
When, according to take until position detection substantially how long determining the size of load next time.Time more it is long then
Load is heavier, is judged to loading when having carried out position detection immediately light.In the conducting for accordingly changing PWM with load like this
When the time, if conduction angle keep 120 degree it is constant if the minimum turn-on time of PWM needed for position detection be unable to get and ensure, because
This, by carrying out Fig. 4 or processing shown in fig. 5, it can be ensured that the minimum turn-on time of PWM.Even if very light in load as a result,
Under conditions of, it can also apply voltage appropriate, realize stable starting.
In addition, the compressor inertia of Reciprocatory is big, speed fluctuation in a short time is few, therefore, even if constriction conduction angle
And be arranged and also hardly have an impact without energization section, compressor 17 can smoothly drive.
Next, being illustrated to freezer 22.Freezer 22 according in library load and external air temperature etc., it is required
Load can dramatically change, especially when external air temperature is 5 DEG C equal, load becomes very small.In such a condition
Under, brushless DC motor 5 starts required application voltage and becomes smaller, and drives the position detection of the brushless DC motor 5 of compressor 17
The minimum turn-on time of required PWM, which is unable to get, to be ensured, brushless DC motor 5 can not start.But in present embodiment
In, by constriction conduction angle, extends the turn-on time of PWM and carry out Fig. 4 and figure in a manner of capable of ensuring the minimum turn-on time of PWM
It is handled shown in 5, it therefore, being capable of starting brushless DC motor 5.
As described above, the motor drive 12 according to an example of embodiment of the present disclosure includes waveform generating unit
10, by PWM generate conduction angle be 120 degree of rectangular waves below or with its comparable waveform；With driving portion 11, according to by
Waveform generating unit 10 generate waveform output drive signal and starting brushless DC motor 5, even if identical PWM carrier wave as a result,
Under frequency, the conducting width of PWM can be also widened.Even if as a result, 120 degree be powered under can not carry out as position detection compared with
The conducting width of narrow PWM, is also able to carry out position detection, realizes stable starting.
In addition, the period of ring is determined by motor or circuit impedance, convergence time is substantially centainly without according to negative
It carries and changes, therefore, width is connected by widening PWM under identical PWM carrier frequency, it can be ensured that until ring convergence
Time can not realize stable driving with being influenced by payload size.
In addition, waveform generating unit 10 exists in the motor drive 12 according to an example of embodiment of the present disclosure
Needed for being unable to ensure the detection of the position of magnetic pole of brushless DC motor 5 when conducting width, the conduction angle less than 120 degree is exported.
According to this structure, it can be started typically without special countermeasure, narrow it in the PWM conducting width that input voltage is got higher etc.
When the abnormality of class, it can be ensured that width is connected in PWM needed for position detection.It can be realized when abnormal as a result,
The driving of stable driving brushless DC motor 5.
In addition, when the inductance for making brushless DC motor 5 is reduced, application voltage needed for the starting of brushless DC motor 5
It reduces, but therefore the minimum turn-on time of PWM needed for keeping identical control that can ensure position detection can use
The inexpensive motor that inductance reduces.
In addition, AC power source 1 is according to from different places and in the presence of the 110V etc. than 100V high.When will be in such AC power source
Voltage high area when making to act when brushless DC motor, application voltage needed for the starting of brushless DC motor is certain, because
This, the turn-on time of PWM shortens.However, because constriction conduction angle extend PWM turn-on time can starting brushless DC it is electronic
Therefore machine can be used in multiple area expansion with single control, can cut down the working hour of exploitation.
In addition, according to the motor drive 12 of an example of embodiment of the present disclosure also may include be assembled with it is brushless
The compressor 17 of DC motor 5.At this point, the load of driving brushless DC motor 5 can be the compression element of compressor 17.Pass through
Using such structure, even if the starting that load is very light, width is connected in PWM needed for can also ensure that position detection.As a result,
The compressor 17 of load not necessarily when can make to start steadily starts.
In addition, the freezer 22 according to an example of embodiment of the present disclosure also may include being sequentially connected compressor
17, the refrigeration cycle of condenser 19, pressure reducer 20, evaporator 21 and compressor 17.By being set as being filled by motor drive
The freezer 22 that 12 startings are assembled with brushless DC motor 5 in compressor 17 is set, even if freezer 22 loads gently, brushless DC electric
Application voltage needed for the starting of machine 5 is small, and width is connected in PWM needed for can also ensure that position detection.Even if refrigerating as a result,
It also can be realized stable starting under the cryogenic conditions that the ambient temperature in library 22 is 5 DEG C or so.
Utilization possibility in industry
Even if can also start motor as described above, load when disclosure offer motor starting is not necessarily
Motor drive.Therefore, can be applied not only to freezer, also can be suitable for air-conditioning, automatic vending machine and showcase,
And compressor of heat pump heat supply hydrophone etc. etc..
Description of symbols
1 AC power source
2 rectification circuits
3 partes glabras
4 inverters
5 brushless DC motors
5a rotor
5b stator
6 position detection parts
7 speed detecting portions
8 apply voltage determination section
9 voltage detection departments
10 waveform generating units
11 driving portions
12 motor drives
17 compressors
19 condensers
20 pressure reducers
21 evaporators
22 freezers.
Claims (4)
1. a kind of motor drive characterized by comprising
Waveform generating unit, using PWM generate conduction angle be 120 degree of rectangular waves below or with its comparable waveform；With
Driving portion, with the waveform output drive signal that is generated by the waveform generating unit come starting brushless DC motor.
2. motor drive as described in claim 1, it is characterised in that:
When waveform generating unit conducting width needed for it cannot ensure the detection of position of magnetic pole of the brushless DC motor,
Export rectangular wave of the conduction angle less than 120 degree or with its comparable waveform.
3. motor drive as claimed in claim 1 or 2, it is characterised in that:
It further include the compressor for being assembled with the brushless DC motor,
Make compression element of the load including the compressor of the brushless DC motor movement.
4. a kind of freezer, it is characterised in that:
Including motor drive as claimed in claim 3,
And including being sequentially connected refrigeration cycle made of the compressor, condenser, pressure reducer and evaporator.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016196909 | 2016-10-05 | ||
| JP2016-196909 | 2016-10-05 | ||
| PCT/JP2017/034849 WO2018066423A1 (en) | 2016-10-05 | 2017-09-27 | Motor drive device and refrigerator using same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109804549A true CN109804549A (en) | 2019-05-24 |
| CN109804549B CN109804549B (en) | 2022-06-24 |
Family
ID=61831717
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201780061436.3A Active CN109804549B (en) | 2016-10-05 | 2017-09-27 | Motor drive device and refrigerator using same |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP7108812B2 (en) |
| CN (1) | CN109804549B (en) |
| WO (1) | WO2018066423A1 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62281701A (en) * | 1986-05-29 | 1987-12-07 | Tokyo R & D:Kk | Speed control unit for electric rolling stock |
| JP2008160950A (en) * | 2006-12-22 | 2008-07-10 | Matsushita Electric Ind Co Ltd | Motor driver and refrigerator possessing it |
| JP2009136149A (en) * | 2009-03-19 | 2009-06-18 | Panasonic Corp | Apparatus for driving brushless dc motor, compressor of refrigerator, and method of driving brushless dc motor |
| CN103546077A (en) * | 2012-07-13 | 2014-01-29 | 三星电子株式会社 | Bldc motor driving apparatus and refrigerator using the same |
-
2017
- 2017-09-27 JP JP2018543855A patent/JP7108812B2/en active Active
- 2017-09-27 CN CN201780061436.3A patent/CN109804549B/en active Active
- 2017-09-27 WO PCT/JP2017/034849 patent/WO2018066423A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62281701A (en) * | 1986-05-29 | 1987-12-07 | Tokyo R & D:Kk | Speed control unit for electric rolling stock |
| JP2008160950A (en) * | 2006-12-22 | 2008-07-10 | Matsushita Electric Ind Co Ltd | Motor driver and refrigerator possessing it |
| JP2009136149A (en) * | 2009-03-19 | 2009-06-18 | Panasonic Corp | Apparatus for driving brushless dc motor, compressor of refrigerator, and method of driving brushless dc motor |
| CN103546077A (en) * | 2012-07-13 | 2014-01-29 | 三星电子株式会社 | Bldc motor driving apparatus and refrigerator using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP7108812B2 (en) | 2022-07-29 |
| CN109804549B (en) | 2022-06-24 |
| JPWO2018066423A1 (en) | 2019-09-05 |
| WO2018066423A1 (en) | 2018-04-12 |
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