CN107222149B - Motor power factor detection system under the conditions of a kind of non-sinusoidal power supply - Google Patents
Motor power factor detection system under the conditions of a kind of non-sinusoidal power supply Download PDFInfo
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- CN107222149B CN107222149B CN201710628800.1A CN201710628800A CN107222149B CN 107222149 B CN107222149 B CN 107222149B CN 201710628800 A CN201710628800 A CN 201710628800A CN 107222149 B CN107222149 B CN 107222149B
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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
- H02P23/00—Arrangements or methods for the control of AC motors characterised by a control method other than vector control
- H02P23/14—Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage
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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
- H02P23/00—Arrangements or methods for the control of AC motors characterised by a control method other than vector control
- H02P23/26—Power factor control [PFC]
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
Motor power factor detection system under the conditions of a kind of non-sinusoidal power supply is to provide the system that motor power factor under the conditions of a kind of accurate non-sinusoidal power supply detects, is measured precisely in real time the power factor of motor under the conditions of non-sinusoidal power supply.It uses the synchronized sampling circuit of high performance voltage and current, in the alternating voltage U (t) and alternating current I (t) that a cycle is T, sampling is synchronized to the three-phase voltage of motor and electric current respectively with the time slot △ t, measures the voltage of three-phase circuit, the phase difference of electric current respectivelyThen the phase difference of the three-phase circuit measured is averaged, and then acquires three-phase average power factor.Three-phase sampling technique can more really reflect the load state of three-phase motor entirety, and the sample frequency of three-phase sampling is three times of single-phase sampling, so the variation to load is more sensitive, response is quicker, keep controller performance more stable, power savings are more preferable.
Description
(1) technical field:
The present invention relates to motor power factor detection systems under the conditions of a kind of non-sinusoidal power supply, can be to non-sinusoidal power supply item
The power factor of motor is measured precisely in real time under part.Its power electronic devices real-time detection motor for passing through motor front end
Load factor and power factor, and then adjust three-phase controllable silicon Trigger Angle, thus reduce input motor voltage and current, into
And reach the energy-saving run of motor.Belong to power electronic technique and electrical machine energy-saving field.
(2) background technique:
The electric energy of threephase asynchronous consumption accounts for 40% or more of whole world total power consumption, wherein there is 60% motor
Operational efficiency is low, to cause a large amount of waste of energy.Under the background of energy growing tension, if can be to phase asynchronous electricity
Motivation carries out energy conservation, then amount of electricity saving is considerable.So expert and scholar point point put into electrical machine energy-saving neck both at home and abroad
Domain has started the development to electric motor saver.Since 20th century, with the rapid development of power electronic technique, electric semiconductor
Converter plant is widely used in electrical machine energy-saving device.Most widely used electric motor saver is all based on the U.S. currently on the market
The power factor electric motor saver that Space Agency Nola develops.It adjusts stator according to relationship corresponding between load and power factor
The size of voltage is held, to realize electrical machine energy-saving.It is the phase for detecting single-phase voltage and electric current in real time by power electronic devices
The method that potential difference carries out cos operation again calculates power factor, then makes comparisons with the power factor set, and then adjusts three
Mutually silicon-controlled Trigger Angle.But the detection method precision of this power factor is not high.On the one hand it is because due to electric power
The presence of electronic device, so that the voltage and current of input motor is distorted, strictly speaking voltage, electric current are all non-sinusoidal
Periodic signal.Power and power factor are tested using the test method under conventional sinusoidal condition of power supply, large error can be generated.
On the other hand, larger to the measurement error of power factor by measuring single-phase voltage, current detecting power factor.Therefore, have
Necessity improves traditional test method, to obtain the authentic data of the parameter of electric machine under the conditions of non-sinusoidal power supply.Therefore, one kind is studied
The new method that motor power factor detects under the conditions of non-sinusoidal power supply, will be an important research to modern electrical machine power-saving technology
Content.
(3) summary of the invention:
Object of the present invention is to solve, the detection system detection accuracy of existing power factor is not high, measurement error is biggish is asked
Topic designs motor power factor detection system under the conditions of a kind of novel non-sinusoidal power supply, it uses high performance voltage and electricity
The synchronized sampling circuit of stream, in the alternating voltage U (t) and alternating current I (t) that a cycle is T, with the time slot △ t difference
Three-phase voltage and electric current to motor synchronize sampling, measure the voltage of three-phase circuit, the phase difference of electric current respectivelyThen the phase difference of the three-phase circuit measured is averaged, and then acquires three-phase average power factor.This
Sample substantially increases the sensitivity and precision of motor power factor detection under the conditions of non-sinusoidal power supply.Power factor detection accuracy
It improves, keeps the power savings of electric motor saver more significant, this has promoted modern electrical machine power-saving technique to higher development.
Technical solution of the present invention:
Motor power factor detection system under the conditions of a kind of non-sinusoidal power supply, it includes voltage acquisition module, current acquisition
Module, ramp generator module, logical network module, power factor instruction module, adder operational amplifier and low-pass filter
Module, slope and error voltage comparison module, IGBT group module, the connection relationship of each module is as shown in Fig. 2, wherein voltage
Acquisition module and the output end of current acquisition module connect the input terminal of logical network module, the output of voltage acquisition module simultaneously
The output end of end while the input terminal for connecting ramp generator module, power factor instruction module and logical network module connects simultaneously
Connect the input terminal of adder operational amplifier and low pass filter blocks, adder operational amplifier and low pass filter blocks and tiltedly
The output end of slope generator module connects slope and error voltage comparison module simultaneously, slope and error voltage comparison module it is defeated
Outlet connects IGBT group module, and IGBT group module is for controlling motor.
Above-mentioned described voltage acquisition module includes that voltage sensor group and voltage calculate amplifier；Current acquisition module packet
It includes current sensor group and electric current calculates amplifier.
The voltage sensor group includes the first phase voltage sensing detected for the A phase input voltage to motor
Device, the second phase voltage sensor detected for the B phase input voltage to motor and for the C phase input voltage to motor
The third phase voltage sensor detected, the first phase voltage sensor is in parallel with the A phase winding of motor, second phase
Voltage sensor is in parallel with the B phase winding of motor, and the third phase voltage sensor is in parallel with the C phase winding of motor；
The current sensor group includes the first phase current sensing detected for the A phase input current to motor
Device, the second phase current sensor detected for the B phase input current to motor and for the C phase input current to motor
The third phase current sensor detected, the first phase current sensor connect the A phase winding and electricity in threephase asynchronous machine
Between the A phase line in source, the second phase current sensor is connect between the B phase winding of motor and the B phase line of power supply, the third
Phase current sensor connects between the C phase winding of motor and the C phase line of power supply.
It includes A phase voltage calculation amplifier, B phase voltage calculation amplifier and C phase voltage that the voltage, which calculates amplifier,
Calculate amplifier.The voltage of A phase voltage calculation amplifier acquisition A phase thyristor front end is made comparisons with ground voltage, output A phase electricity
Press square-wave signal；The voltage of B phase voltage calculation amplifier, acquisition B phase thyristor front end is made comparisons with low-voltage is connect, and exports B phase
Voltage square wave signal；The voltage of C phase voltage calculation amplifier, acquisition C phase thyristor front end is made comparisons with low-voltage is connect, and exports C
Phase voltage square-wave signal.The electric current calculates amplifier, including A phase current calculates amplifier, B phase current calculate amplifier and
C phase current calculates amplifier.The electric current that A phase current calculating amplifier acquires A phase thyristor front-end and back-end respectively is made comparisons, defeated
A phase current square-wave signal out；B phase current calculates amplifier, and the electric current for acquiring B phase thyristor front-end and back-end respectively is made comparisons,
Export B phase current square-wave signal；C phase current calculates amplifier, and the electric current for acquiring C phase thyristor front-end and back-end respectively makees ratio
Compared with output C phase current square-wave signal.
Above-mentioned described logical network module includes that A phase logic network, B phase logic network and C phase logic network, A phase are patrolled
Collect the current square wave of the voltage square wave signal that network exports A phase voltage calculation amplifier and the calculating amplifier output of A phase current
Signal is compared, and exports A phase voltage current phase difference signal；The electricity that B phase logic network exports B phase voltage calculation amplifier
The current square-wave signal that pressure square-wave signal and B phase current calculate amplifier output is compared, and exports B phase voltage current and phase difference
Signal；The voltage square wave signal and C phase current that C phase logic network exports C phase voltage calculation amplifier calculate amplifier output
Current square-wave signal be compared, export C phase voltage current phase difference signal.
Above-mentioned described ramp generator module includes A phase ramp generator, B phase ramp generator, the generation of C phase slope
Device；A phase ramp generator issues A phase ramp signal, and B phase ramp generator issues B phase ramp signal, C phase ramp generator hair
C phase ramp signal out.
Above-mentioned described adder operational amplifier and low pass filter blocks include adder operational amplifier and low-pass filtering
Device two parts；The adder operational amplifier is by A phase logic network, and three of B phase logic network and the output of C phase logic network
Voltage current phase difference signal carries out summation operation, and the power factor command signal issued with power factor instruction module makees ratio
Compared with exporting an error signal；The error signal that adder operational amplifier exports is filtered place by the low-pass filter
Reason.
Above-mentioned described slope and error voltage comparator module include that A phase slope and error voltage comparator, B phase are oblique
Slope and error voltage comparator, C phase slope and error voltage comparator.
The ramp voltage signal and addition that the A phase slope and error voltage comparator issues A phase ramp generator
Operational amplifier and the error signal of low pass filter blocks output are compared, and export A phase trigger signal, the brilliant lock of triggering A phase
The conducting of pipe；B phase slope and error voltage comparator put the ramp voltage signal that B phase ramp generator issues with add operation
Big device and the error signal of low pass filter blocks output are compared, and export B phase trigger signal, and triggering B phase thyristor is led
It is logical；Ramp voltage signal that C phase slope and error voltage comparator issue C phase ramp generator and adder operational amplifier and
The error signal of low pass filter blocks output is compared, and exports C phase trigger signal, triggers the conducting of C phase thyristor.
The working principle of the invention:
The working principle for the new method that motor power factor detects under the conditions of a kind of non-sinusoidal power supply involved in this case are as follows:
It uses the synchronized sampling circuit of high performance voltage and current, in the alternating voltage U (t) and alternating current I that a cycle is T
(t), sampling is synchronized to the three-phase voltage of motor and electric current respectively with the time slot △ t, measures the electricity of three-phase circuit respectively
The phase difference of pressure, electric currentThen the phase difference of the three-phase circuit measured is averaged, and then acquires three-phase
Average power factor.Collection voltages, electric current are distinguished by two groups of Independent adjustable resistor networks, this resistor network allows each
There is voltage difference between phase line terminal and motor side, it in this way can be in a respective thyristor of suitable voltage triggered.
Advantages of the present invention and have the technical effect that three-phase sampling technique is all adopted by each phase to three phase mains
Sample, and summation operation is carried out, it can more really reflect the load state of three-phase motor entirety.The sample frequency of three-phase sampling
It is three times of single-phase sampling.Single-phase sampling half period can only detect once, and three-phase sampling half period can detect three times.Cause
And use the technology of three-phase sampling that can more quickly detect the variation of load, and be adjusted to the output of controller,
So the variation to load is more sensitive, response is quicker, keeps controller performance more stable, power savings are more preferable.
(4) Detailed description of the invention:
Attached drawing 1 is the asynchronous electricity in " a kind of non-sinusoidal power supply under the conditions of motor power factor detection system " involved by the present invention
Motivation three-phase average power factor survey calculation functional block diagram.
Attached drawing 2 is the asynchronous electricity in " a kind of non-sinusoidal power supply under the conditions of motor power factor detection system " involved by the present invention
Motivation three-phase activity coefficient testing principle block diagram.
(5) specific embodiment:
Embodiment: motor power factor detection system under the conditions of a kind of non-sinusoidal power supply (see Fig. 1,2), the detection system packet
Include voltage acquisition module, current acquisition module, ramp generator module, logical network module, power factor instruction module, addition
Operational amplifier and low pass filter blocks, slope and error voltage comparison module, IGBT group module, voltage acquisition module
Connect the input terminal of logical network module simultaneously with the output end of current acquisition module, the output end of voltage acquisition module connects simultaneously
Connect the input terminal of ramp generator module, the output end of power factor instruction module and logical network module connects addition fortune simultaneously
Calculate the input terminal of amplifier and low pass filter blocks, adder operational amplifier and low pass filter blocks and ramp generator
The output end of module connects slope and error voltage comparison module simultaneously, and slope is connected with the output end of error voltage comparison module
IGBT group module, IGBT group module is for controlling motor.Above-mentioned described voltage acquisition module includes electricity
Pressure sensor group and voltage calculate amplifier；Current acquisition module includes that current sensor group and electric current calculate amplifier.
Described ramp generator module includes A phase ramp generator, B phase ramp generator, C phase ramp generator.Institute
The logical network module said includes A phase logic network, B phase logic network, C phase logic network.Described slope and error voltage
Comparison module includes A phase slope and error voltage comparator, B phase slope and voltage comparator, C phase slope and voltage comparator.
Thyristor module of setting out includes A phase IGBT group, B phase IGBT group, C phase IGBT group.
The detection process of motor power factor detection system under the conditions of a kind of non-sinusoidal power supply, at least includes the following steps:
Step A: voltage and current Acquisition Circuit distinguishes the A phase voltage of motor in real time stator side, electric current, B phase voltage, electricity
Stream, C phase voltage, electric current, the voltage for being separately input to A phase calculates amplifier, electric current calculates amplifier, and the voltage calculating of B phase is put
Big device, electric current calculate amplifier, and the voltage of C phase calculates amplifier, electric current calculates amplifier.
Step B: the voltage signal of acquisition compared with ground voltage, is exported the electricity of each phase by the voltage calculating amplifier of each phase
Press square-wave signal.The electric current of each phase calculates amplifier and the current signal of acquisition is made comparisons, and exports the current square-wave signal of each phase.
Step C: the ramp generator of each phase receives the two-way voltage square wave signal that amplifier is calculated from voltage, generates each
The ramp signal of phase.
Step D: logical network module calculates the voltage square wave signal of A phase voltage calculation amplifier output and A phase current
The current square-wave signal of amplifier output is compared, and exports A phase voltage current phase difference signal.B phase voltage calculation is amplified
The current square-wave signal that the voltage square wave signal and B phase current of device output calculate amplifier output is compared, and exports B phase voltage
Current phase difference signal.The voltage square wave signal of C phase voltage calculation amplifier output and C electric current are calculated to the electricity of amplifier output
Stream square-wave signal is compared, and exports C phase voltage current phase difference signal.
Step E: adder operational amplifier is by A phase logic network, and three of B phase logic network and the output of C phase logic network
Voltage current phase difference signal carries out summation operation, and the power factor command signal issued with power factor instruction module makees ratio
Compared with exporting an error signal.
Step F: by low-pass filter, the error signal that adder operational amplifier exports is filtered.
The ramp voltage signal and addition that step G:A phase slope and error voltage comparator issue A phase ramp generator
Operational amplifier and the error signal of low pass filter blocks output are compared, and export A phase trigger signal, the brilliant lock of triggering A phase
The conducting of pipe；B phase slope and error voltage comparator put the ramp voltage signal that B phase ramp generator issues with add operation
Big device and the error signal of low pass filter blocks output are compared, and export B phase trigger signal, and triggering B phase thyristor is led
It is logical；Ramp voltage signal that C phase slope and error voltage comparator issue C phase ramp generator and adder operational amplifier and
The error signal of low pass filter blocks output is compared, and exports C phase trigger signal, triggers the conducting of C phase thyristor.
Claims (2)
1. motor power factor detection system under the conditions of a kind of non-sinusoidal power supply, it is characterised in that including voltage acquisition module, electricity
Flow acquisition module, ramp generator module, logical network module, power factor instruction module, adder operational amplifier and low pass
Filter module, slope and error voltage comparison module, IGBT group module, voltage acquisition module and current acquisition module
Output end connects the input terminal of logical network module simultaneously, and the output end of voltage acquisition module connects ramp generator module simultaneously
Input terminal, the output end of power factor instruction module and logical network module connects adder operational amplifier and low pass filtered simultaneously
The output end of the input terminal of wave device module, adder operational amplifier and low pass filter blocks and ramp generator module is simultaneously
Connection slope and error voltage comparison module, slope connect IGBT group module with the output end of error voltage comparison module,
IGBT group module is for controlling motor；
The logical network module includes A phase logic network, B phase logic network and C phase logic network, and A phase logic network is by A
The current square-wave signal that the voltage square wave signal and A phase current of phase voltage calculation amplifier output calculate amplifier output is compared
Compared with output A phase voltage current phase difference signal；The voltage square wave signal that B phase logic network exports B phase voltage calculation amplifier
The current square-wave signal for calculating amplifier output with B phase current is compared, and exports B phase voltage current phase difference signal；C phase is patrolled
Collect the current square wave of the voltage square wave signal that network exports C phase voltage calculation amplifier and the calculating amplifier output of C phase current
Signal is compared, and exports C phase voltage current phase difference signal；
The ramp generator module includes A phase ramp generator, B phase ramp generator, C phase ramp generator；
The A phase ramp generator issues A phase ramp signal, and the B phase ramp generator issues B phase ramp signal, institute
The C phase ramp generator stated issues C phase ramp signal；
The adder operational amplifier and low pass filter blocks includes adder operational amplifier and low-pass filter two parts；
Three voltages that the adder operational amplifier exports A phase logic network, B phase logic network and C phase logic network
Current phase difference signal carries out summation operation, and the power factor command signal issued with power factor instruction module is made comparisons,
Export an error signal；The error signal that adder operational amplifier exports is filtered by the low-pass filter；
The slope and error voltage comparator module includes A phase slope and error voltage comparator, B phase slope and error electricity
Press comparator, C phase slope and error voltage comparator；
The ramp voltage signal and add operation that the A phase slope and error voltage comparator issues A phase ramp generator
Amplifier and the error signal of low pass filter blocks output are compared, and export A phase trigger signal, triggering A phase thyristor
Conducting；The ramp voltage signal and adder operational amplifier that B phase slope and error voltage comparator issue B phase ramp generator
It is compared with the error signal of low pass filter blocks output, exports B phase trigger signal, trigger the conducting of B phase thyristor；C
The ramp voltage signal and adder operational amplifier and low pass that phase slope and error voltage comparator issue C phase ramp generator
The error signal of filter module output is compared, and exports C phase trigger signal, triggers the conducting of C phase thyristor.
2. motor power factor detection system under the conditions of non-sinusoidal power supply according to claim 1, it is characterised in that described
Voltage acquisition module include that voltage sensor group and voltage calculate amplifier；Current acquisition module include current sensor group and
Electric current calculates amplifier；
The voltage sensor group include the first phase voltage sensor detected for the A phase input voltage to motor,
The second phase voltage sensor for being detected for the B phase input voltage to motor and for the C phase input voltage to motor into
The third phase voltage sensor of row detection, the first phase voltage sensor is in parallel with the A phase winding of motor, the two phase electricity
Pressure sensor is in parallel with the B phase winding of motor, and the third phase voltage sensor is in parallel with the C phase winding of motor；
The current sensor group includes the first phase current sensor detected for the A phase input current to motor, uses
It the second phase current sensor for being detected in the B phase input current to motor and is carried out for the C phase input current to motor
The third phase current sensor of detection, the first phase current sensor connect in the A phase winding of threephase asynchronous machine and the A of power supply
Between phase line, the second phase current sensor is connect between the B phase winding of motor and the B phase line of power supply, the third phase electricity
Flow sensor connects between the C phase winding of motor and the C phase line of power supply；
It includes A phase voltage calculation amplifier, B phase voltage calculation amplifier and C phase voltage calculation that the voltage, which calculates amplifier,
Amplifier；The voltage of A phase voltage calculation amplifier, acquisition A phase thyristor front end is made comparisons with ground voltage, exports A phase voltage
Square-wave signal；The voltage of B phase voltage calculation amplifier, acquisition B phase thyristor front end is made comparisons with low-voltage is connect, output B phase electricity
Press square-wave signal；The voltage of C phase voltage calculation amplifier, acquisition C phase thyristor front end is made comparisons with low-voltage is connect, and exports C phase
Voltage square wave signal；
The electric current calculates amplifier, including A phase current calculates amplifier, and B phase current calculates amplifier and C phase current calculates
Amplifier；A phase current calculates amplifier, and the electric current for acquiring A phase thyristor front-end and back-end respectively is made comparisons, output A phase electricity
Flow square-wave signal；B phase current calculates amplifier, and the electric current for acquiring B phase thyristor front-end and back-end respectively is made comparisons, and exports B phase
Current square-wave signal；C phase current calculates amplifier, and the electric current for acquiring C phase thyristor front-end and back-end respectively is made comparisons, and exports C
Phase current square-wave signal.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201710628800.1A CN107222149B (en) | 2017-07-28 | 2017-07-28 | Motor power factor detection system under the conditions of a kind of non-sinusoidal power supply |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201710628800.1A CN107222149B (en) | 2017-07-28 | 2017-07-28 | Motor power factor detection system under the conditions of a kind of non-sinusoidal power supply |
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| CN107222149A CN107222149A (en) | 2017-09-29 |
| CN107222149B true CN107222149B (en) | 2019-09-17 |
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| CN108809196B (en) * | 2018-07-11 | 2020-05-22 | 阳光电源股份有限公司 | Motor driver's voltage parameter detection device and motor driver |
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| CN101694984A (en) * | 2009-10-16 | 2010-04-14 | 华中科技大学 | Asynchronous motor energy saver |
| CN102006003A (en) * | 2010-12-01 | 2011-04-06 | 于洋 | Three-phase asynchronous motor economizer |
| CN107645264B (en) * | 2012-08-10 | 2021-03-12 | 艾默生环境优化技术有限公司 | Control circuit, drive circuit and method for controlling motor of compressor |
| CN106026787A (en) * | 2016-07-11 | 2016-10-12 | 太原理工大学 | Five-stage discrete frequency-conversion soft-start device based on power factor angle closed-loop control |
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