CN102790562A - Method for smoothly switching motor between variable-frequency power supply and power-frequency power supply - Google Patents
Method for smoothly switching motor between variable-frequency power supply and power-frequency power supply Download PDFInfo
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- CN102790562A CN102790562A CN2012102839500A CN201210283950A CN102790562A CN 102790562 A CN102790562 A CN 102790562A CN 2012102839500 A CN2012102839500 A CN 2012102839500A CN 201210283950 A CN201210283950 A CN 201210283950A CN 102790562 A CN102790562 A CN 102790562A
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Abstract
The invention relates to a method for smoothly switching a motor between a variable-frequency power supply and a power-frequency power supply. Switching the motor from variable-frequency power drive to power-frequency power drive includes the following steps: the wiring phase sequence between the motor and an inverter is adjusted; the inverter is operated to have switching target frequency; the phase of the variable-frequency power supply is adjusted to be ahead of the phase of the power-frequency power supply; and the electric connection between the variable-frequency power supply and the motor is cut off, so that the power-frequency power supply is electrically connected with the motor. Switching the motor from power-frequency power drive to variable-frequency power drive includes the following steps: the wiring phase sequence between the motor and the inverter is adjusted; when the error between the phase of the power-frequency power supply and a preset switching phase angle is less than 6 degrees, the variable-frequency power supply starts to operate with the preset switching target frequency and the preset switching phase angle, but does not output PWM (pulse width modulation) signals; and the electric connection between the power-frequency power supply and the motor is cut off, so that the variable-frequency power supply is electrically connected with the motor. The method can smoothly switch the motor between the variable-frequency power supply and the power-frequency power supply.
Description
Technical field
The present invention relates to method that motor is taken over seamlessly between variable frequency power supply and power frequency supply.
Background technology
In some blower fan water pump, staircase control occasion, tend to require motor between frequency conversion drive and power frequency driving, to switch back and forth, energy-conservation to realize, as to improve load capacity purpose, the application scenario that is used as soft initiator at frequency converter also has similar requirement sometimes.Impulse current when the serious problems that switching exists between power frequency and frequency conversion are switching, present solution has:
1. the method for " throwing afterwards earlier and cutting ".Power frequency supply and variable frequency power supply are simultaneously online between transfer period, and this method requires the necessary strict unanimity of amplitude, phase angle of two power supplys, because any difference of amplitude phase angle all can cause very big impulse current to produce during parallel connection.For avoiding impulse current to cause frequency converter damage or motor to be hit, this method also adds suitable reactor between power frequency supply and variable frequency power supply, but is to use reactor to increase the cost and the volume of handover control system, has also increased power consumption simultaneously;
2. drive motor through frequency converter and run to 50Hz (or bigger), break off variable frequency power supply then, power frequency is inserted in the time-delay back, and the impulse current of this method is also bigger.
Summary of the invention
Technical problem to be solved by this invention is to overcome the above-mentioned defective of prior art, provide a kind of use cost low, have less impulse current when switching, can realize the method that motor takes over seamlessly between variable frequency power supply and power frequency supply.
The technical scheme that the present invention adopted is: a kind of method that motor is taken over seamlessly between variable frequency power supply and power frequency supply; Comprise motor is switched to the power frequency supply driving and motor is switched to the variable frequency power supply driving by the power frequency supply driving by the variable frequency power supply driving, wherein:
A, motor driven by variable frequency power supply switch to power frequency supply and drive and may further comprise the steps:
Wiring phase sequence between A-1, adjustment motor and the frequency converter, the direction of rotation of motor is consistent when switching to the power frequency supply driving with assurance by the variable frequency power supply driving;
A-2, make frequency converter run to the switching target frequency set, the size of this switching target frequency is 49Hz～51Hz;
The phase place of A-3, adjustment variable frequency power supply makes the phase place of variable frequency power supply be ahead of the phase place of power frequency supply;
A-4, when the leading power frequency supply one predetermined angle β in variable frequency power supply phase angle, variable frequency power supply is closed PWM output, breaks off being electrically connected between variable frequency power supply and the motor, after time-delay, power frequency supply and motor is electrically connected;
B, motor driven by power frequency supply switch to variable frequency power supply and drive and may further comprise the steps:
B-1, at first adjust wiring phase sequence between motor and the frequency converter, consistent to guarantee driving when switching to variable frequency power supply and driving the direction of rotation of motor by power frequency supply;
B-2, when the error at the phase place of power frequency supply and preset switching phase angle is in 6 °, variable frequency power supply brings into operation with preset switching target frequency and said preset switching phase angle but output pwm signal not;
Being electrically connected between B-3, disconnection power frequency supply and the motor after time-delay, is electrically connected variable frequency power supply and motor, and makes the variable frequency power supply output pwm signal.
The invention has the beneficial effects as follows:
Since between transfer period variable frequency power supply and power frequency supply not online simultaneously, so need not increase extra reactor, can not cause possible large impact electric current because of the off delay of contactor at power frequency supply yet.Simultaneously, the present invention need not wait winding back emf to reduce just can switch to variable frequency power supply, has reduced the variation of motor speed between transfer period;
2. the smooth-switching method that is converted to power frequency can make frequency converter use as soft initiator, switches to by power frequency supply after earlier taking to motor about 50Hz by frequency converter to drive again, the impulse current that has brought when having avoided direct power frequency starter motor;
3. because the impulse current when having suppressed to switch makes that also torque shock ends diminishes, the mechanical shock in the time of can reducing to switch.
Description of drawings
Fig. 1 is driven motor to switch to the schematic flow sheet that power frequency supply drives according to an embodiment of the invention by variable frequency power supply.
Fig. 2 is driven motor to switch to the schematic flow sheet that variable frequency power supply drives according to an embodiment of the invention by power frequency supply.
Fig. 3 is the theory diagram of one embodiment of the invention.
Embodiment
Below in conjunction with accompanying drawing the present invention is made further explanation.
A kind of according to an embodiment of the invention method that motor is taken over seamlessly between variable frequency power supply and power frequency supply comprises motor is switched to the power frequency supply driving and motor is switched to the variable frequency power supply driving by the power frequency supply driving by the variable frequency power supply driving, wherein:
A, motor driven by variable frequency power supply switch to power frequency supply and drive and may further comprise the steps:
Wiring phase sequence between A-1, adjustment motor and the frequency converter, the direction of rotation of motor is consistent when switching to the power frequency supply driving with assurance by the variable frequency power supply driving.In the practical operation, in the time of can be through wiring with two exchanges mutually.
A-2, frequency converter make frequency converter run to the switching target frequency of a setting behind the switching command that receives " the frequency conversion cut frequently ", and the size of this switching target frequency is 49Hz～51Hz.
The phase place of A-3, adjustment variable frequency power supply makes the phase place of variable frequency power supply be ahead of the phase place of power frequency supply.
This step specifically may further comprise the steps again:
Through the output voltage signal of voltage collecting device collection power frequency supply, obtain the voltage waveform signal of any phase among R, S, the T, then the voltage waveform signal of this phase is exported to variable frequency power supply;
Variable frequency power supply is handled the voltage waveform signal of this phase, obtains the current phase place of power frequency supply through the mode of zero crossing detection;
The phase place that is ahead of power frequency supply through the frequency of adjustment variable frequency power supply or phase place that phase place makes variable frequency power supply.
In a specific embodiment, as shown in Figure 3, voltage collecting device is a voltage acquisition plate 3.Voltage acquisition plate 3 is with the waveform signal of the R phase voltage of the power frequency supply that collects 1; Deliver to the phase detecting module of variable frequency power supply through the analog input mouth AI1 of variable frequency power supply (frequency converter) 2; Phase detecting module detects the current phase place that the back obtains power frequency supply through zero crossing; Afterwards, the phase place that is ahead of power frequency supply through the frequency of adjustment variable frequency power supply or phase place that phase place makes variable frequency power supply.
A-4, when the preset angle beta of the leading power frequency supply in the phase angle of variable frequency power supply one, variable frequency power supply is closed PWM output, breaks off being electrically connected between variable frequency power supply and the motor, after time-delay, power frequency supply and motor is electrically connected;
In one embodiment, 0 °＜β≤15 °.In the embodiments of figure 3, be to realize being electrically connected and breaking off between variable frequency power supply and the motor 4, through being electrically connected and breaking off between power frequency supply contactor KM2 realization power frequency supply 1 and the motor 4 through a variable frequency power supply contactor KM1.Preferably, variable frequency power supply contactor KM1 and power frequency supply contactor KM2 interlocking.When the preset angle beta of the leading power frequency supply in the phase angle of variable frequency power supply one, variable frequency power supply 2 is closed PWM output, and variable frequency power supply contactor KM1 breaks off.Time-delay back adhesive power frequency supply contactor KM2 switches to power frequency control with motor.The mechanical electric inherent characteristic of contactor has determined the length of this time-delay, and 10 ~ 30ms generally delays time.The purpose of time-delay is in order to guarantee that two power supplys are not online simultaneously between transfer period.Because the action delay of contactor; Be disconnected to the adhesive of power frequency supply contactor from the variable frequency power supply contactor and probably need time a few tens of milliseconds; Motor is in free operating condition during this section; The phase place and the power frequency supply of winding back emf are consistent in order to guarantee to insert power frequency constantly, and the variable frequency power supply contactor preferably makes variable frequency power supply phase angle certain angle of leading power frequency supply when breaking off.
B, motor driven by power frequency supply switch to variable frequency power supply and drive and may further comprise the steps:
B-1, at first adjust wiring phase sequence between motor and the frequency converter, consistent to guarantee driving when switching to variable frequency power supply and driving the direction of rotation of motor by power frequency supply.
B-2, variable frequency power supply are behind the switching command that receives " the power frequency shear frequently "; When the error at the phase place of power frequency supply and preset switching phase angle was in 6 °, variable frequency power supply brought into operation with preset switching target frequency and said preset switching phase angle but output pwm signal not.Wherein, preset switching phase angle is meant that its size can be an arbitrary value at the phase angle of the variable frequency power supply that is provided with in advance on the variable frequency power supply when switching.
Being electrically connected between B-3, disconnection power frequency supply and the motor after time-delay, is electrically connected variable frequency power supply and motor, and makes the variable frequency power supply output pwm signal.In a kind of preferred embodiments,, revise the output voltage of frequency converter in real time through the PID current regulator in the moment that variable frequency power supply and motor are electrically connected.This PID current regulator compares the actual output current of the frequency converter of feedback and given frequency converter rated current, if switching moment actual current has surpassed rated current, the PID current regulator begins to regulate.
In the example depicted in fig. 3, through breaking off power frequency supply contactor KM2, break off being electrically connected between power frequency supply and the motor.After the time-delay, adhesive variable frequency power supply contactor KM1 makes variable frequency power supply 2 and motor 4 be electrically connected variable frequency power supply 2 output pwm signals.At this moment; Motor 4 switches to variable frequency power supply 2 controls; In the moment that variable frequency power supply 2 and motor 4 are electrically connected, can revise the output voltage of frequency converter through current regulator in real time, the output valve of current regulator is added on the output voltage of original frequency conversion; Output voltage to frequency converter is revised in real time, to suppress impulse current.
Said method is elaborated with a concrete application example below in conjunction with Fig. 3.
At first, the wiring phase sequence between adjustment motor and the frequency converter, the motor direction of rotation when guaranteeing power frequency supply 1 drive motors with variable frequency power supply 2 drive motors is consistent.Receive the switching command of " the frequency conversion cut frequently " in variable frequency power supply 2 after, variable frequency power supply runs to " switching target frequency " (like the 49.50Hz) of setting earlier, adjusts the phase place of variable frequency power supply 2 then; Make the phase place of variable frequency power supply 2 be ahead of the phase place of power frequency supply 1; When leading power frequency supply 1 certain angle in the phase angle of variable frequency power supply 2 (as 10 °), variable frequency power supply 2 is closed PWM output, makes variable frequency power supply contactor KM1 dead electricity; Motor 4 and variable frequency power supply 2 are broken off on electric; After time-delay, adhesive power frequency supply contactor KM2 switches to motor 4 by power frequency supply 1 control.
Receive the order of " power frequency change frequently " at frequency converter after, when the error of the phase place of power frequency supply 1 and preset phase place commuting angle is in 6 °, variable frequency power supply 2 with preset switching target frequency with switch the phase angle and bring into operation but do not export PWM; Break off power frequency supply contactor KM2 simultaneously; Make power frequency supply contactor dead electricity, motor 4 and power frequency supply 1 are broken away from, time-delay back adhesive variable frequency power supply contactor KM1; Variable frequency power supply contactor KM1 is got; After the variable frequency power supply contactor KM1 adhesive, the variable frequency power supply output pwm signal, this moment, motor 4 switched to by variable frequency power supply 2 controls; Output voltage in access moment variable frequency power supply 2 can suitably reduce, and revises the output voltage of variable frequency power supply simultaneously in real time through current regulator.
The present invention can be applicable to staircase control.Staircase nobody the time drive with frequency converter and to make low cruise, when detecting the someone and will get into staircase, staircase is driven by frequency converter and accelerates to 50Hz, switches to then by power frequency to drive.Reached purpose of energy saving so on the one hand, because staircase is having man-hour to be driven by power frequency, this can adopt low power frequency converter, saves the control system cost on the other hand.
Claims (6)
1. the method that motor is taken over seamlessly between variable frequency power supply and power frequency supply is characterized in that, comprise motor is switched to the power frequency supply driving and motor is switched to the variable frequency power supply driving by the power frequency supply driving by the variable frequency power supply driving, wherein:
A, motor driven by variable frequency power supply switch to power frequency supply and drive and may further comprise the steps:
Wiring phase sequence between A-1, adjustment motor and the frequency converter, the direction of rotation of motor is consistent when switching to the power frequency supply driving with assurance by the variable frequency power supply driving;
A-2, make frequency converter run to the switching target frequency set, the size of said switching target frequency is 49Hz～51Hz;
The phase place of A-3, adjustment variable frequency power supply makes the phase place of variable frequency power supply be ahead of the phase place of power frequency supply;
A-4, when the leading power frequency supply one predetermined angle β in variable frequency power supply phase angle, variable frequency power supply is closed PWM output, breaks off being electrically connected between variable frequency power supply and the motor, after time-delay, power frequency supply and motor is electrically connected;
B, motor driven by power frequency supply switch to variable frequency power supply and drive and may further comprise the steps:
B-1, at first adjust wiring phase sequence between motor and the frequency converter, consistent to guarantee driving when switching to variable frequency power supply and driving the direction of rotation of motor by power frequency supply;
B-2, when the error at the phase place of power frequency supply and preset switching phase angle is in 6 °, variable frequency power supply brings into operation with preset switching target frequency and said preset switching phase angle but output pwm signal not;
Being electrically connected between B-3, disconnection power frequency supply and the motor after time-delay, is electrically connected variable frequency power supply and motor, and makes the variable frequency power supply output pwm signal.
2. the method that motor is taken over seamlessly between variable frequency power supply and power frequency supply as claimed in claim 1 is characterized in that, described steps A-3 further may further comprise the steps:
Gather the output voltage signal of said power frequency supply through a voltage collecting device, obtain the voltage waveform signal of any phase, then the voltage waveform signal of this phase is exported to variable frequency power supply;
Variable frequency power supply is handled the voltage waveform signal of this phase, obtains the current phase place of power frequency supply through the mode of zero crossing detection;
The phase place that is ahead of power frequency supply through the frequency of adjustment variable frequency power supply or phase place that phase place makes variable frequency power supply.
3. the method that motor is taken over seamlessly between variable frequency power supply and power frequency supply as claimed in claim 1; It is characterized in that; In the described step B-3 step,, revise the output voltage of frequency converter in real time through the PID current regulator in the moment that variable frequency power supply and motor are electrically connected.
4. the method that motor is taken over seamlessly between variable frequency power supply and power frequency supply as claimed in claim 1 is characterized in that, 0 °＜β≤15 °.
5. the method that motor is taken over seamlessly between variable frequency power supply and power frequency supply as claimed in claim 1; It is characterized in that; In the method; Be to realize being electrically connected and breaking off between said variable frequency power supply and the motor, realize being electrically connected and breaking off between said power frequency supply and the motor through a power frequency supply contactor through a variable frequency power supply contactor.
6. the method that motor is taken over seamlessly between variable frequency power supply and power frequency supply as claimed in claim 1 is characterized in that, in the method, and described variable frequency power supply contactor and the interlocking of described power frequency supply contactor.
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| Application Number | Priority Date | Filing Date | Title |
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| CN2012102839500A CN102790562A (en) | 2012-08-10 | 2012-08-10 | Method for smoothly switching motor between variable-frequency power supply and power-frequency power supply |
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| CN2012102839500A CN102790562A (en) | 2012-08-10 | 2012-08-10 | Method for smoothly switching motor between variable-frequency power supply and power-frequency power supply |
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104506110A (en) * | 2014-10-09 | 2015-04-08 | 上海海泰克系统工程有限公司 | Motor frequency conversion frequency tracking and switching method |
| CN104753408A (en) * | 2015-03-20 | 2015-07-01 | 苏寿喜 | High power motor switching control system and switching method |
| CN105281609A (en) * | 2015-10-23 | 2016-01-27 | 首钢京唐钢铁联合有限责任公司 | Control system and control method for external bypass running of soft starter |
| CN105656389A (en) * | 2016-03-25 | 2016-06-08 | 无锡市优利康电气有限公司 | Power frequency and variable frequency switching method |
| CN105676742A (en) * | 2016-03-14 | 2016-06-15 | 广东明阳龙源电力电子有限公司 | Control method for non-disturbance switching between power frequency and variable frequency of high-voltage inverter |
| CN105720609A (en) * | 2014-12-05 | 2016-06-29 | 淮安庄子电气有限公司 | Frequency conversion and power frequency synchronous switching implementation method |
| CN104201938B (en) * | 2014-07-30 | 2017-01-11 | 广州智光电气股份有限公司 | Frequency converter soft start method based on CPLD |
| CN106533319A (en) * | 2016-10-29 | 2017-03-22 | 上海新时达电气股份有限公司 | Traceless switching method of variable frequency and power frequency |
| CN107408901A (en) * | 2015-03-10 | 2017-11-28 | 株式会社明电舍 | Synchronizing Control Devices for electric power converter |
| CN109921718A (en) * | 2017-12-12 | 2019-06-21 | 日立楼宇技术（广州）有限公司 | Escalator is exchanged work switches compensation angle method of adjustment and system frequently |
| CN112615571A (en) * | 2020-12-08 | 2021-04-06 | 西安热工研究院有限公司 | Frequency conversion and power frequency switching control method for induced draft fan of garbage power plant |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104201938B (en) * | 2014-07-30 | 2017-01-11 | 广州智光电气股份有限公司 | Frequency converter soft start method based on CPLD |
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| CN107408901A (en) * | 2015-03-10 | 2017-11-28 | 株式会社明电舍 | Synchronizing Control Devices for electric power converter |
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| CN105281609A (en) * | 2015-10-23 | 2016-01-27 | 首钢京唐钢铁联合有限责任公司 | Control system and control method for external bypass running of soft starter |
| CN105676742A (en) * | 2016-03-14 | 2016-06-15 | 广东明阳龙源电力电子有限公司 | Control method for non-disturbance switching between power frequency and variable frequency of high-voltage inverter |
| CN105676742B (en) * | 2016-03-14 | 2018-07-03 | 广东明阳龙源电力电子有限公司 | The control method of switching undisturbed between a kind of high-voltage frequency converter power frequency and frequency conversion |
| CN105656389A (en) * | 2016-03-25 | 2016-06-08 | 无锡市优利康电气有限公司 | Power frequency and variable frequency switching method |
| CN106533319A (en) * | 2016-10-29 | 2017-03-22 | 上海新时达电气股份有限公司 | Traceless switching method of variable frequency and power frequency |
| CN106533319B (en) * | 2016-10-29 | 2019-03-29 | 上海新时达电气股份有限公司 | Frequency conversion and power frequency without trace switching method |
| CN109921718A (en) * | 2017-12-12 | 2019-06-21 | 日立楼宇技术（广州）有限公司 | Escalator is exchanged work switches compensation angle method of adjustment and system frequently |
| CN109921718B (en) * | 2017-12-12 | 2021-01-26 | 日立楼宇技术（广州）有限公司 | Method and system for adjusting variable working frequency switching compensation angle of escalator |
| CN112615571A (en) * | 2020-12-08 | 2021-04-06 | 西安热工研究院有限公司 | Frequency conversion and power frequency switching control method for induced draft fan of garbage power plant |
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Application publication date: 20121121 |