NL2032361A - Motor control system and method - Google Patents

Motor control system and method Download PDF

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Publication number
NL2032361A
NL2032361A NL2032361A NL2032361A NL2032361A NL 2032361 A NL2032361 A NL 2032361A NL 2032361 A NL2032361 A NL 2032361A NL 2032361 A NL2032361 A NL 2032361A NL 2032361 A NL2032361 A NL 2032361A
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Netherlands
Prior art keywords
current
feedback
unit
phase
harmonic
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NL2032361A
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Dutch (nl)
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NL2032361B1 (en
Inventor
Liu Bing
Yin Chao
Li Feng
Chu Kongfei
Bai Donghai
Sun Shaonan
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Shandong Bocheng Electric Co Ltd
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Publication of NL2032361A publication Critical patent/NL2032361A/en
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Publication of NL2032361B1 publication Critical patent/NL2032361B1/en

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/01—Arrangements for reducing harmonics or ripples
    • 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
    • H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
    • H02P29/50—Reduction of harmonics
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/12—Arrangements for reducing harmonics from ac input or output
    • H02M1/126—Arrangements for reducing harmonics from ac input or output using passive filters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
    • 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
    • H02P23/0004—Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
    • H02P23/0018—Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control using neural networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
    • H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
    • H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0009—Devices or circuits for detecting current in a converter
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H02M1/325—Means for protecting converters other than automatic disconnection with means for allowing continuous operation despite a fault, i.e. fault tolerant converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
    • H02M5/42—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
    • H02M5/44—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
    • H02M5/453—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M5/458—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M5/4585—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only having a rectifier with controlled elements
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/40—Arrangements for reducing harmonics

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Artificial Intelligence (AREA)
  • Evolutionary Computation (AREA)
  • Inverter Devices (AREA)
  • Control Of Ac Motors In General (AREA)

Abstract

The invention relates to a motor control system and method, belongs to the technical field of control, and solves a problem that suppression of harmonic 5 components and safe and stable operation of a frequency converter cannot be considered at the same time. The system is characterized in that a power grid side reactor and a feedback side reactor are electrically connected with a regulator, wherein the control center generates a first control signal to a third control signal and provides the signals to the regulator; when the frequency converter works in the first quadrant and the third quadrant, the harmonic component of the three- phase AC voltage is removed through the load current compensation unit; when the frequency converter works at a second quadrant and a fourth quadrant, the regulator enables the feedback current filtering unit to filter harmonic current in feedback current; and when the determiner determines that the feedback current filtering unit works abnormally, the feedback current compensation unit offsets the harmonic current in the feedback current. The harmonic component of the three- phase AC voltage of the driving motor is removed through the load current compensation unit, and the harmonic component in the feedback current is removed through the filtering unit or the feedback current compensation unit.

Description

Motor control system and method Technical field The present invention relates to the field of control technology, in particular to a motor control system and method. Background of the disclosure in modern power systems, with the large-scale integration of inverter devices involved in distributed energy generation, the power qualily characteristics of the power grid have become increasingly complex, and the harmonics in the power grid have also attracted more and more attention. The concept of harmonics has been widely valued because the intervention of non-linear devices such as power electronic equipment has brought huge challenges to the stable operation of the power grid and the correct action of relay protection. At the same time, since most of the full-control devices use PWM control technology, the system will produce a large number of switching frequency sub-harmonics. This will not only affect the waveform and quality of the output current, but also bring many unfavorable factors to the work of the phase-locked loop. For the power quality of the power grid, the IEEE Sid 1547-2003 standard stipulates the upper limit of the harmonic componenis of the grid-connected current as follows: | | | RE | Harmonic Order h | | | | Harmonic | (Odd Harmonie) heit | 11sh<17 | 17sh<23 | 23sh<35 | 35sh | Distortion | Proportion of | | | | | Rated Grid | | | | | Connected 40 2.0 | 1.5 | 0.6 | 0.3 | 5.0 | Current | | | | When the harmonic current is even-numbered, its allowable maximum harmonic limit is 25% of the odd harmonic in the table. Therefore, when the existing frequency converter suppresses the harmonic component through the filter, it usually introduces the problem that it cannot operate stably.
Summary of the disclosure in view of the above analysis, the embodiments of the present invention aim to provide a motor control system and method to solve the problem that the existing system cannot balance the suppression of harmonic components and the safe and stable operation of the inverter.
Cn the one hand, an embodiment of the present invention provides a motor control system including: a regulator, a control center, a grid-side reactor and a feedback- side reactor, a load current compensation unit, and a feedback current compensation unit, wherein the grid-side reactor and the feedback-side reactor are respectively electrically connected to the regulalor via the first input and output end and the second input and output end of the regulator; the control center is communicatively connected to the regulator via the third input and output end of the regulator, and is used to generale the first control signal to the third control signal and providing them to the regulator, The regulator includes a filter capacitor, when the frequency converter works in the first and third quadrants, the rectifier/shared inverter unit of the frequency converter generates the three-phase AC voltage that drives the motor, and the harmonic components of the three-phase AC voltage, or the harmonic components and reactive components of the three-phase AC voltage are removed by the load current compensation unit; when the frequency converter works in the second and fourth quadrants, the regulator connects the feedback side reactor and the filter capacitor via the first control signal and the second control signal, so that the filter capacitor, the fesdback-side reactor, and the grid-side reactor constitute a feedback current filtering unit to filter out harmonic currents in the feedback current; and the control center includes a determiner, when the determiner determines the feedback current filtering unit works abnormally, the regulator is also used to turn off the feedback current filtering unit via the first control signal and the second control signal, and connect the feedback current compensation via the third control signal unit to offset the harmonic current in the feedback current.
The advantageous sffects of the above technical solution are as follows: when the inverter works in the first and third quadrants, the harmonic components of the three-phase AC voltage, or the harmonic components and reactive components of the three-phase AC voltage are removed by the load current compensation unit; When the inverter is working in the second and fourth quadrants, the filter capacitor, the feedback-side reactor and the grid-side reactor are connected as the feedback current filler unit (Le. the LCL filter unit) through the regulator, so that the harmonic components in the feedback current can be filtered out by the feedback current filter unit prior to the feedback current is fed back io the three-phase power grid, so as to improve the power quality of the grid. Optionally, when the determiner determines that the feedback current filter unit is working abnormally, the feedback current compensation unit is used instead of the feedback current filter unit to generate a harmonic current to offset the harmonic components in the feedback current.
Based on a further improvement of the above system, the frequency converter further includes a feedback unit, wherein the rectifier unit is electrically connected to the three-phase power grid to convert the three-phase power grid voltage into a direct current voltage, and the power grid voltage has a first frequency. The shared inverter unit is electrically connected to the rectifier unit to convert the DC voltage into the three-phase AC voltage of the second frequency or convert the three- phase AC voltage when the motor is braking into the DC voliage. And the feedback unit, the input end of which is connected to the connection point between the rectifier unit and the common inverter unit, and the output end of which is connected to the feedback side reactor for converting the DC voltage into the three- phase grid voltage is used to feed the feedback current back to the grid. The advantageous effect of the above further improved solution is that the inverter of the embodiment of the present application separates the rectification channel and the feedback channel through an additional feedback unit, so that different filters can be used to independently filter the rectification channel and the feedback channel. Based on the further improvement of the above system, the load current compensation unit has its input end connected to the connection point, and is output end connected between the common inverter unit and the motor, and is used to provides a first compensation current when rectifying/shared inverter unit generates a load current, wherein the amplitude of the first compensation current is equal to the amplitude of the harmonic current in the load current, and the direction of the first compensation current is opposite to the harmonic current in the load current. The feedback current compensation unit has its input terminal connected lo the connection point, and its output terminal connected to the output terminal of the feedback unil. When the operation of the feedback current filter unit is abnormal, the feedback current compensation unit provides a second compensation current, wherein the amplitude of the second compensation current is equal to the amplitude of the harmonic current in the feedback current, and the direction of the second compensation current is opposite to the harmonic current in the feedback current.
The advantageous effect of the above-mentioned further improvement scheme is that the feedback current compensation unit is used as a backup filter unit of the feedback current filter unit, and can continue to suppress the harmonic components of the feedback current through the backup filter unit when the feedback current filter unit cannot filter the feedback current normally, so thai to ensure that the feedback system can operate safely and stably.
Based on a further improvement of the above system, the motor control system further includes a first signal detection device, wherein the first signal detection device is connected between the grid and the grid-side reactor for real-time detection of three-phase grid voltage and current, and the detected information is supplied to the control center via the regulator.
Based on a further improvement of the above system, when the determiner determines that the harmonic current in the three-phase grid current detected by the first signal detection device is not filtered out or the specified sub-harmonic current cannot be filtered out, the feedback current filter unit works abnormally.
The advantageous effect of the above-mentioned further improvement scheme is: since the filter capacitor, the feedback-side reactor and the grid-side reactor in the feedback current filter unit are fixed, the feedback current filter unit has a fixed resonance frequency, that is, the inverter system is are prone to oscillations near the resonance frequency, which makes the feedback current filter unit unable to filter the feedback current normally (Le. works abnormally). Furthermore, when the feedback current filtering unit works abnormally, the harmonic components are suppressed by the feedback current compensation unit.
Based on a further improvement of the above system, the abnormal operation of the feedback current filtering unit includes: abnormal operation of any one or more of the grid-side reactor, the feedback-side reactor, and the filter capacitor; and the resistor in the feedback current filter unit connected in series with the filter capacitor is short-circuited; and the resonant frequency of the feedback current filter unit is close to the specified sub-harmonic frequency.
5 Based on a further improvement of the above system, the regulator further includes a first switching device, a second switching device, and a third switching device. The first switching device is turned on or off according to the first control signal, io connect or disconnect the feedback-side reactor and the grid-side reactor. The second switching device is turned on or off according to the second control signal to connect or disconnect the filter capacitor. And the third switching device is turned on or off according to a third control signal provided by the control center to tum on or off the feedback current compensation unit.
Based on the further improvement of the above system, the regulator is also used to: when the frequency converter is working in the first and third quadrants, the first switching device, the second switching device and the third switching device are disconnected according to the first control signal to the third control signal, and the grid current is filtered through the grid-side reactor; and when the frequency converter works in the second and fourth quadrants, the first switching device and the second switching device is turned on according to the first control signal and the second control signal, and the third switching device is turned off according to the third control signal, so that the feedback current filter unit which firmed with the filter capacitor and the feedback reactor and the grid-side reactor filters the feedback current.
The advantageous effect of the above-mentioned further improvement scheme is that the regulator controls each switching device according to the control signal from the control center, so that when the inverter is working in the first and third quadrants, each switching device is controlled according to the first control signal to the third the signal is disconnected, so that the grid-side reactor can be used as the input reactor lo prevent the inverter from being damaged by the grid impulse current; and when the inverter works in the second and fourth quadrants, the first switching device and the second swilching device are turned on according to the first control signal and the second control signal, and the third switching device is turned off according to the third control signal, so that the filter capacitor, the feedback-side reactor and the grid-side reactor are connected as a feedback current filter unit to filter out the harmonic components in feedback current.
Based on the further improvement of the above system, the regulator is also used 10: when the inverter works in the second and fourth quadrant conditions and the feedback current filtering unit works abnormally, the first switching device and the second switching device is turned off according to the first control signal and the second control signal, and the third switching device is turned on according to the third control signal, so as to cancel the harmonic current in the feedback current through the feedback current compensation unit.
Based on the further improvement of the above system, the control center also includes an AFE control unit, where the AFE control unit includes: a Pl adaptive control module which is used as a controller of the inverter system to control the feedback unit; and an RBF neural network self-updating module for receiving the output of the feedback unit and the output of the Pl adaptive control module, and comparing the output of the RBF neural network self-updating module with the output of the feedback unit, and then use the gradient descent method to update the output weight, base width vector and node vector of the network at each moment in real time, and the Jacobian matrix is obtained according to the updated output weight, the base width vector and the node vector.
The Jacobian matrix is connected in parallel to the Pl adaptive control module to optimize the proportional parameters and integral parameters of the Pl adaptive control module.
Based on a further improvement of the above system, the motor control system further includes a second signal detection device and a third signal detection device, wherein the second signal detection device is connected between the feedback unit and the feedback side reactor for real-time detection of the three- phase feedback voltage and current and providing them to the control center via the regulator; and the third signal detection device for real-time detection of the three-phase capacitance current and voltage of the filter capacitor and providing it to the control center via the regulator.
Based on the further improvement of the above system, the control center further includes a receiving module and a calculation module, wherein the receiving module is configured to receive the three-phase grid voltage and current, the three-
phase feedback voltage and the current and the three-phase capacitor current and voltage.
The calculation module is configured to obtain the mathematical model of the feedback current filtering unit according to the feedback current filtering unit, and obtain the transfer function of inverter system of frequency convertor according tothe mathematical model, wherein the inverter system includes a feedback current filter unit, the feedback unit and the AFE control unit.
Based on the further improvement of the above system, the control center further includes a first harmonic current detection module, a first harmonic current control module, a second harmonic current detection module, and a second harmonic current control module.
The first harmonic current detection module is used to detect the harmonic components or the harmonic components and reactive power components in the load current, and the second harmonic current detection module is used to detect the harmonic components in the feedback current; and the first harmonic current detection module and the second harmonic current detection module both include a current conversion unit, a low-pass filter, a current inverse conversion unit, and an addition unit.
The current conversion unit is used lo convert the three-phase load current or the three-phase feedback current inio a two-phase orthogonal rotating coordinate system dg to generale the dg axis current.
The digital low-pass filler is used to filter out the dg axis harmonics component from the dg axis current, or filter out the dg-axis harmonic component and reactive component to output the dg-axis DC component.
The current inverse conversion unit is used io convert the dg-axis DC component into the three-phase base of the three-phase load current wave component or the three-phase fundamental wave component in the three-phase feedback current.
The adding unit is configured to subtract the three-phase fundamental wave component from the three-phase load current or the three-phase feedback current to obtain the harmonic components in the a three-phase load current or the harmonic components in the three-phase load current wave component and reactive components in the three-phase load current,
or obtain the harmonic components in the three-phase feedback current.
The first harmonic current control module is used to generale a control signal of the load current compensation unit according to the harmonic component in the three-phase load current or the harmonic component and the reactive component in the three- phase load current.
The second harmonic current control module is used {o generate a control signal of feedback current compensation unit according io the harmonic components in the three-phase feedback current.
Based on a further improvement of the above system, the load current compensation unit includes a first three-phase bridge converter.
The first three-
phase bridge converter is controlled according to the control signal of the load current compensation unit received from the control center, the six switching devices in the first three-phase bridge converter perform real-time turn-on and furm- off control so that the first three-phase bridge converter generates the first compensation current.
The feedback current compensation unit includes a second three-phase bridge converter, wherein, according to the control signal of the feedback current compensation unit received from the control center, six switching devices in the second three-phase bridge converter are controlled to perform real- time on and off control, so that the second three-phase bridge converter generates the second compensation current, On the other hand, an embodiment of the present invention provides a motor control method, including: generating a first control signal to a third control signal through a control center and sending # to a regulator; when the frequency converter is working in the first and third quadrants, the rectifier/shared inverter unit of the frequency converter generates the three-phase AC voltage that drives the motor, and the load current compensation unit removes the harmonic components of the three-phase AC voltage, or the harmonic components of the three-phase AC voltage and reactive power component; when the frequency converter is working in the second and fourth quadrants, the regulator is connected to the feedback side reactor and the filter capacitor via the first control signal and the second control signal, so that the filter capacitor, the feedback-side reactor and the grid-side reactor constitute a feedback current filter unit to filter out harmonic currents in the feedback current; and when the determiner determines that the feedback current filter unit works abnormally, the regulator passes through the first control signal and the second control signal disconnect the feedback current filter unit and connect the feedback current compensation unit via the third control signal to cancel the harmonic current in the feedback current.
Compared with the prior art, the present invention can achieve at least one of the following advantageous effects:
1. When the inverter works in the second and fourth quadrants, the filter capacitor, the feedback side reactor and the grid side reactor are connected as the feedback current filtering unit through the regulator, so that the feedback current can be filtered out the harmonic components in the feedback current before the feedback current is fed back to the three-phase grid, thereby improving the power guality of the power grid. Optionally, when the determiner determines that the feedback current filter unit is working abnormally, instead of the feedback current filter unit, the feedback current compensation unit generates a harmonic current lo offset the harmonic components in the feedback current.
2. The regulator controls each switching device according to the control signal from the control center, so that when the inverter is working in the first and third quadrants, each switching device is disconnected according to the first control signal to the third control signal, so that the grid-side reactor is used as an input reactor to prevent the inverter from being damaged by the inrush current of the grid; and when the inverter is working in the second and fourth quadrants, the filter capacitor, the feedback side reactor and the grid side reactor are connected as the feedback current filter unit to filter out the harmonic components in the feedback current.
3. Adopting the adjustable filter unit of the adaptive control module based on the RBF neural network, the response speed in response to the sudden change in the power of the feedback unit is significantly improved. The adjustable filter unit not only reduces the size, but also can be used as the input reactor of the frequency converter under the control logic arrangement, which improves the efficiency of the filter.
in the present invention, the above-mentioned technical solutions can also be combined with each other to realize more preferred combination solutions. Other features and advantages of the present invention will be described in the following specification, and part of the advantages may become obvious from the specification or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the content specifically pointed out In the description and the drawings. Brief description of the drawings The drawings are only used for the purpose of illustrating specific embodiments, and are not considered as a limitation to the present invention. Throughout the drawings, the same reference signs represent the same components. Fig. 1 is a block diagram of a motor control system according to an embodiment of the present invention. Fig. 2 is a specific structure diagram of a frequency converter according to an embodiment of the present invention. Fig. 3 is a topological structure diagram of a feedback unit according 10 an embodiment of the present invention, Fig. 4 is a block diagram of an adaptive control unit model based on an HBF neural network according to an embodiment of the present invention.
Figure 5 shows the grid current waveforms of the traditional feedback current filter unit in the feedback unit full-load feedback and half-load feedback. Fig. 6 is a grid current waveform of the feedback current filter unit in the feedback unit full-load feedback and half-load feedback according to an embodiment of the present invention. Fig. 7 is a grid current waveform of the feedback current filter unit in the feedback unit is full-load and half-load feedback jumps according to an embodiment of the present invention. Fig. 8 is a block diagram of a control center including a harmonic current detection module and a harmonic current control module according to an embodiment of the present invention.
Fig. 9 is a schematic diagram of a harmonic current detection module according to an embodiment of the present invention.
Fig. 10 is a flowchart of a filtering method according to an embodiment of the present invention.
Detailed description of the preferred embodiments The preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
The accompanying drawings constitute a part of the application and are used together with the embodiments of the present invention to explain the principle of the present invention, and are not used to limit the scope of the present invention.
A specific embodiment of the present invention discloses a motor control system.
As shown in FIG. 1, the motor control system includes: a frequency converter, a regulator 106, a control center 110, a grid-side reactor 102, a feedback-side reactor 104, a load current compensation unit 120, and a feedback current compensation unit 114. Specifically, the grid-side reactor 102 and the feedback-side reactor 104 are electrically connected to the regulator 108 via a first input and output end and a second input and oulput end of the regulator 108, respectively.
The control center 110 is communicatively connected with the regulator 106 via the third input and output terminal of the regulator 108, and is used to generate the first control signal to the third control signal and provide them lo the regulator 106. The regulator 106 includes a filter capacitor 108. When the inverter works in the first and third quadrants, the rectifying/shared inverter unit 118 of the inverter generates a three- phase AC voltage for driving the motor, and the load current compensation unit 120 removes the three-phase AC voltage Harmonic components, or harmonic components and reactive components of three-phase AC voltage; when the inverter is working in the second and fourth quadrants, the regulator is connected 10 the feedback side reactor 104 and the filler capacitor 108 makes the filter capacitor 108, the feedback-side reactor 104 and the grid-side reactor 102 constitute a feedback current filtering unit to filter out harmonic currents in the feedback current.
The control center 110 includes a determiner 116, When the determiner 116 determines that the feedback current filler unit is working abnormally, the regulator 106 is also used to disconnect the feedback current filter unit via the first control signal and the second control signal, and connect to the feedback current compensation unit 114 via the third control signal in order to offset the harmonic current in the feedback current.
Compared with the prior art, in the motor control system provided by this embodiment, when the inverter works in the first and third quadrants, the harmonic components of the three-phase AC voltage, or the harmonic components and reactive components of the three-phase AC voltage are removed by the load current compensation unit; When the inverter is working in the second and fourth quadrants, the filter capacitor, the feedback-side reactor and the grid-side reactor are connected as the feedback current filter unit through the regulator {can be called LVL filter), so that the harmonic components in the feedback current can be filtered out by the feedback current filter unit prior to the feedback current is fed back to the three-phase power grid, so as to improve the power quality of the grid.
Optionally, when the determiner determines that the feedback current filter unit is working abnormally, instead of the feedback current filter unit, the feedback current compensation unit generates a harmonic current to offset the harmonic components in the feedback current.
Hereinafter, the motor control system according lo the embodiment of the present invention will be described in detail with reference to FIG. 1 to 4. The motor control system includes a frequency converter, a regulator 106, a control center 110, a grid-side reactor 102, a feedback-side reactor 104, a feedback current compensation unit 114, a load current compensation unit 120, a first signal detection device, and a second signal detection device and the third signal detection device, wherein the frequency converter includes a rectifier unit, a common inverter unit and a feedback unit 112.
Referring to FIG. 2, the rectifier unit is electrically connected to the three-phase power grid to convert the three-phase power grid voltage into a direct current voltage, and the power grid voltage has a first frequency. The shared inverter unit is electrically connected to the rectifier unit to convert the DC voltage into a three- phase AC voltage of the second frequency for driving the motor or convert the three-phase AC voltage when the motor is braking into a DC voltage, wherein the grid voltage is different for the three-phase AC voltage, or the second frequency can be the same or different from the first frequency, the three-phase AC voltage with the second frequency is suitable for driving the motor. The feedback unit {refer to Figure 1 and Figure 2), its input terminal is connected to the connection point between the rectifier unit and the common inverter unit, and its output terminal is connected to the feedback side reactor to convert the DC voltage to the three- phase grid voltage in order lo feed the feedback current back to the grid. Therefore, the common inverter unit is shared between the rectification channel and the feedback channel, that is, the common inverter unit is used as the inverter unit in the rectification channel and as the rectifier unit in the feedback channel.
The grid-side reactor 102 and the feedback-side reactor 104 are electrically connected to the regulator 106 via a first input and output end and a second input and oulput end of the regulator 106, respectively, The control center 110 is communicatively connected with the regulator 106 via the third input and output terminal of the regulator 108. The control center 110 is used to generate the first control signal to the third control signal and provide them to the regulator 106. Referring to FIG. 2, the regulator further includes a first switching device, a second switching device, and a third switching device. The first switching device KM1 is turned on or off according to the first control signal to connect or disconnect the feedback-side reactor with the grid-side reactor; the second switching device KM2 is turned on or off according to the second control signal, lo connect or disconnect the filter capacitor; and the third switching device KM3 is turned on or off according tc the third control signal provided by the control center to turn the feedback current compensation unit on or off.
The first signal detection device, wherein the first signal detection device is connected between the power grid and the grid-side reactor for real-time delection of the three-phase power grid voltage and current and provided to the control center via the regulator, The second signal detection device is connected between the feedback unit and the fsedback-side reactor to detect the three-phase feedback voltage and current in real time and provide them to the control center via the regulator. The third signal detection device is used to delect the three-phase capacitance current and voltage of the filter capacitor in real time and provide them to the control center via the regulator,
Specifically, referring to Figure 2, when the frequency converter works in the first and third quadrants, the first switching device, the second switching device, and the third switching device are turned off according to the first control signal to the third control signal, and the grade current is filtered through the grid-side reactor L2.
Therefore, the grid-side reactor L2 is used as an input reactor to prevent damage to the inverter caused by the grid inrush current. Referring to Figure 2, when the inverter works in the first and third quadrants, the rectifier/shared inverter unit 118 (Le. the rectifier unit and the shared inverter unit) ol the inverter generates a three-phase AC voltage for driving the motor, and the load current compensation unit 120 removes the harmonic components of the three-phase AC voltage, or the three-phase AC vollage Harmonic and reactive components of AC voltage. The input end of the load current compensation unit 120 is connected to the connection point, and the culput end is connected between the common inverter unit and the motor, and is used to provide the first compensation current when the rectifier/shared inverter unit generates load current. The amplitude of the first compensation current is equal to the amplitude of the harmonic current in the load current, and the direction of the first compensation current is opposite to the harmonic current in the load current, so that the first compensation current can offset the harmonic current in the load current. In an alternative embodiment, the load current compensation unit 120 generales a first compensation current, the first compensation current includes the sum of the harmonic current and the reactive current in the load current, so as to be able to remove the harmonic current and the reactive current in the load current.
Referring to Figure 1, the regulator 108 includes a filter capacitor 108, When the inverier works in the second and fourth quadrants, the regulator connects the feedback side reactor 104 and the filler capacitor 108 via the first control signal and the second control signal, so that the filter capacitor 108, the feedback-side reactor 104 and the grid-side reactor 102 form a feedback current filtering unit to filter out harmonic currents in the feedback current. Specifically, when the frequency converter works in the second and fourth quadrants, the first switching device and the second switching device are turned on according 19 the first control signal and the second control signal, and the third switching device is turned off according to the third control signal, so that the feedback current is filtered by a feedback current filter unit composed of a filter capacitor, a feedback-side reactor and a grid-side reactor. The combination of the feedback-side reactor 104, the grid-side reactor 102, and the regulator 106 comprising the filter capacitor 108 can be used as an adjustable filter unit. In addition, three resistors R are connected in series with three filter capacitors C respectively, and the series branch is connected in parallel with the feedback branch, which can prevent resonance problems to a certain extent, and the parallel resistors and filter capacitors will not reduced the voltage value of the feedback voltage. in addition, although the resistor can prevent the resonance problem to a certain extent, when the feedback current filter unit itself malfunctions, or near the resonance frequency of the feedback current filter unit, it is easy to cause the feedback current filter unit to work abnormally. In order to ensure that the inverter can operate safely and stably and provide high-quality feedback current, the inverter of the embodiment of the present invention is also provided with a feedback current compensation unit. The regulator is also used for when the inverter is working in the second and fourth quadrants and the feedback current filtering unit works abnormally, the first switching device and the second switching device are turned off according to the first control signal and the second control signal, and the third The switching device is turned on according to the third control signal to offset the harmonic current in the feedback current through the feedback current compensation unit.
Because the parameter size of the traditional filter can directly affect the overall performance of the system, the following parameter requirements usually need to be considered: {1)The total inductance has a limit: the impedance voltage drop under rated conditions must be less than 10% of the grid voltage; (2)Limitations on filter capacitors: Excessive filter capacitors will produce a large amount of reactive power loss and reduce the overall power handling capacity of the Inverter; (3)Resonance frequency limitation: In order to avoid the resonant frequency becoming a restrictive factor in the design of the feedback unit current controller, it is generally required that the resonant frequency of the feedback current filter unit be designed to be between 10 times the fundamental frequency and 0.5 times the switching frequency; {4} Limitations on the damping resistor R: When R is larger, the resonance peak is reduced more obviously, but the loss of the filter also increases, and the filler performance of the filter to high-frequency harmonics will also be reduced. Therefore, this application uses an adjustable filter unit to optimize the proportional parameter Kp and the integral parameter K by using an adaptive control module based on the RBF neural network, Hereinafter, the adaptive control module based on the BBF neural network to optimize the proportional parameter Kp and the integral parameter K will be described in detail.
The control center also includes a receiving module and a calculation module. The receiving module is used {co receive the three-phase grid vollage and current, the three-phase feedback voltage and current, and the three-phase capacitor current and voltage from the regulator; and the calculation module is used to obtain the mathematical model of the feedback current filter unit according to the feedback current filter unit, and obtain the transfer function of the inverter system according to the mathematical model, wherein, the inverter system includes a feedback current filter unit, a feedback unit and an AFE control unit. The feedback current filter unit and the feedback unit are arranged outside the control center. Referring to FIG. 3, the feedback unit is a three-phase bridge converter, and the three-phase bridge converter includes 8 switching devices.
Specifically, the calculation module is used to obtain a three-phase mathematical model according to the feedback current filter unit, convert the three-phase mathematical model into a mathematical model of a two-phase orthogonal aB axis stationary coordinate system, and convert the mathematical model of the aff axis stationary coordinate system converted to a mathematical model in a synchronously rotating dg-axis coordinate system to obtain the transfer function of the feedback current filter unit.
The three-phase mathematical model of the feedback current filter unt is:
d i ul a | Li lln) = [Us| — {Yop | dt Iie Ue Ure le] ie ee Lo be) = {Ucn | — Mop { dt boe Ure Uge | ica bg ba | Lp} = flip [los | ice ie 2e seals | icy wo een Ury L {ce dt Uce The mathematical model under the dq axis coordinate system is: dig Ugg | Ug | de LT, a dig teg Va da Ln diz _ Yea Ugd | wi ren ZE ven vn ven (035 dt Ly, Lb, 3 dig Ugg Ugg / dt Ly Lp td a CC digg bg be | de TT We Wherein, the feedback-side reactor Ls, filter capacitor C, and grid-side reactor Ls are composed; ia, le, and bic are the three-phase currents of the feedback unit; hg, itg are the d and g-axis currents of the feedback unit ua, Us, and U. are the three- phase voltages of the feedback unit; ica, Ic, and ice are the three-phase currents flowing through the filter capacitor; ic, lg are the d and g axis currents flowing through the filter capacitor; Ucs, Uct, Uc are the voltages of the filter capacitor; ucq, ugg are the d and q axis voltages of the filter capacitor; bx, by, and ie are the three- phase currents on the grid side; ix, ix are the d, g on the grid side Shaft current; ga, Ugh, Uge are the three-phase voltage on the grid side; ugs and ugg are the d and g axis voltages on the grid side.
Obtain the transfer function of the inverter feedback system according to the transfer function of the feedback current filter unit: ON Giny Gi (8) Among them, Gin is the AFE transfer function, Gin=Uq/2; Hi is the capacitive current active damping feedback coefficient; Gus} is the current regulator; Gos) is the voltage regulator, Gi{s) and Giz(s} all adopt Pi control regulator, and its transfer function is: G(s) = Kp + A, among them, Ke is a proportional parameter, and K is an integral parameter. Referring to Figure 4, the control center includes an AFE control unit, where the AFE control unit includes: a Pl adaptive control module, used as a controller of the inverter of the inverter system to control the feedback unit; and an RBF neural network selt-updaling module for receive the output of the feedback unit and the output of the Pl adaptive control module, compare the output of the RBF neural network self-renewal module with the output of the feedback unit, and then use the gradient descent method to determine the output weight, base width vector and the output of the network at each moment. The node vector is updated in real time. According to the updated output weight, base width vector and node vector, the Jacobian matrix is obtained, and the Jacobian matrix is connected to the Pi adaptive control module in parallel to optimize the proportional parameter Kp and integral of the Pl adaptive control module Parameters K, Therefore, the use of the adjustable filter unit based on the RBF neural network adaptive control module, the optimized proportional parameter Ke and the integral parameter K,, significantly improves the response speed when the power of the feedback unit changes suddenly.
The control center 110 includes a determiner 118. When the determiner 118 determines that the feedback current filter unit is working abnormally, the regulator 106 is also used to disconnect the feedback current filter unit via the first control signal and the second control signal and connect the feedback current compensation unit 114 via the third control signal. The feedback current compensation unit 114 is used to offset the harmonic current in the feedback current. When the determiner 118 determines that the harmonic current in the three-phase grid current detected by the first signal detection device is not filtered out or the specified sub-harmonic current cannot be filtered out, the feedback current filtering unit works abnormally. Specifically, the abnormal operation of the feedback current filtering unit includes: abnormal operation of any one or more of the grid-side reactor, the feedback-side reactor, and the filter capacitor; the resistor in the feedback current filter unit connected in series with the filter capacitor is short-circuited; and the resonant frequency of the feedback current filer unit is close to the specified subharmonic frequency.
The feedback current compensation unit has is input terminal connected to the connection point and its output terminal connected to the output terminal of the feedback unit for providing a second compensation current when the feedback current filter unit works abnormally, wherein the second compensation current amplitude is equal to the amplitudes of the harmonic currents in the feedback current, and the direction of the second compensation current is opposite to the direction of the harmonic currents in the feedback current.
The feedback current compensation unit includes a three-phase bridge converter, wherein, according to the control signal of the feedback current compensation unit received from the control center, six switching devices in the three-phase bridge converter are controlled to conduct real-time turn-on and turn-off in order to generales a second compensation current by the three-phase bridge converter.
Referring to FIG. 8, the control center also includes a harmonic current detection module 802 and a harmonic current control module 804. The harmonic current detection module 802 is used to detect the harmonic components in the feedback current, and includes a current conversion unit 806, a digital low-pass filter 808, a current inverse conversion unit 810, and an addition unit 812. The current conversion unit 8086 is used 10 convert the three-phase feedback current into a two- phase orthogonal rotating coordinate system dq to generale a dg axis current.
The digital low-pass filter 808 ís used to filter the dg-axis harmonic component from the dg-axis current to output the dg-axis DC component.
The current inverse conversion unit 810 is used to convert the dg-axis direct current component into the three-phase fundamental wave component in the three-phase feedback current.
The adding unit 812 is configured lo subtract the three-phase fundamental wave component from the three-phase feedback current to obtain the harmonic components in the three-phase feedback current.
The harmonic current control module 804 is configured to generate a control signal of the feedback current compensation unit according io the harmonic components in the three-phase feedback current.
Referring to FIG. 8, the control center further includes a first harmonic current detection module 802 and a first harmonic current control module 804. The first harmonic current detection module 802 is used to detect harmonic components or harmonic components and reactive components in the load current, and the first harmonic current detection modules all include a current conversion unit, a low- pass filter, and a current inverse conversion unit and the addition unit. The current conversion unit 806 is used to convert the three-phase load current info a two- phase orthogonal rotating coordinate system dq to generale a dg axis current. The digital low-pass filter 808 is used to filter the dg-axis harmonic components from the dg-axis current. The current inverse conversion unit 810 is used to convert the dg- axis direct current component into the three-phase fundamental wave component in the three-phase load current. In an alternative embodiment, when the first harmonic current detection module 802 is used to detect harmonic components and reactive components, the digital low-pass filter 808 is used to filter the d-axis harmonic components from the d-axis current to output d DC component, and the g-axis current is set to 0; accordingly, the d DC component is converted into the three- phase fundamental wave component in the three-phase load current. The adding unit 812 is configured lo subtract the three-phase fundamental wave component from the three-phase load current to obtain the harmonic component in the three- phase load current, or the harmonic component and the reactive component in the three-phase load current. The first harmonic current control module 804 is configured to generate a control signal of the load current compensation unit according to the harmonic component in the three-phase load current or the harmonic component and the reactive component in the three-phase load current.
The load current compensation unit includes a three-phase bridge converter. When the motor is driven, the six switching devices in the three-phase bridge converter are controlled to conduct real-time tum on and turn off control according to the control signal of the load current compensation unit received from the control center, so that the three-phase bridge converter generates a first compensation current. When the motor is braking, a stop control signal is received from the control center to control the 6 switching devices to turn off, so thal the first compensation current is no longer generated.
Hereinafter, referring to FIGS. 2 to 8, the frequency converter according to the embodiment of the present invention will be described in detail in the form of specific examples.
The adjustable filter unit is digitally modeled according to the operating conditions of the inverter (as the following formulas 1 and 2), and calculate the grid-side reactance value, rectifier-side reactance value, and filter capacitor through software simulation and optimization design for each operating state of the filter value, damping resistance value, elc., and optimized with the design parameters of the inverter; in order io ensure the grid-connected current quality of the feedback unit, the current sensor is installed on the grid side to facilitate the monitoring of the grid side current. Refer to Figure 2, which consists of a feedback unit, a rectifier-side reactor L1, a filter capacitor C, and a grid-side reactor L2. U is the DC side voltage of the feedback unit; Coe is the DC side capacitance of the feedback unit; iia, In, lic are the three-phase current of the feedback unit; ica, ics, and ic are the three-phase current of the filter capacitor; ina, bon, and ix are the power grid side three-phase current; according to the mathematical model of KVL, KCL (Kirhholf's CurrentLaw) law in the three-phase static coordinate system, as shown in formula 1, the Laplace transform of formula 1 is performed to obtain the mathematical model under dg coordinates, the formula 2 shows: . ia ty Urea i kip de Ure | la] [Yea] [Ha i se Ue Uge . | Hed Reed LED igh | tcp] = Io} [zo | ice tic èze i ica tea io = cu Cb} = LOR tee Uce 1 _ WierlcagtWliligd dg 7 Lys , _ UgagUgagtelalzga cag = iy dg ~~ {zag Ugag = aient
The transfer function of the feedback system derived from the above formula 2 is: Gu Gis (5) Ga (9) 0 NEL Cer BCH GG valid +L 1 G06 {}
Inthe formula, Gn, is the AFE transfer function, Giw=Uu/2; Hi is the capacitive current active damping feedback coefficient; Gis} is the current regulator; G(s) is the voltage regulator.
Gis) and G(s) both use Pl control regulalors, and their transfer function is:
G(s) = Kp +2
Due to the large steady-state tracking error of traditional PI controller regulators, and the controller parameters still rely on the accuracy of system modeling, at present only approximate models can be obtained for the four-quadrant inverter AFE, but accurate modeling cannot be achieved due to the low robustness of the system, In order to solve the above problems, adaptive control is added to the traditional Pl controller to increase the robustness of the system and reduce the steady-state error of the grid-connecied current.
The control strategy of this application consists of three parts: the first part is the adaptive control of the K, and Ki coefficients of the Pl controller (RBF neural network algorithm), so that the controller paramsters can be seli-adjusied according to the external disturbance and error of the system.
The addition of the adaptive control does not change the system transfer function; the second part is to suppress the resonance problem generated by the feedback current filter unit and reduce the grid current ripple; the third part is to add capacitive current active damping feedback to the BBF network adaptive control strategy, effectively solve the resonance problem of the feedback current filter unit.
The control center collects real-time detection signals (current, voltage, etc.) of the regulator, and performs real-time signal processing through the adaptive control of the BBF neural network and the inverter control unit of the control center and AFE {Active Front End) control unit.
The obtained optimal control parameters are used to adjust the regulator to ensure that the adjustable filler unit works at the best condition.
The adaptive control unit model based on RBF neural network is shown in Figure 4. The model includes: Pl adaptive regulator and RBF network; the parameters of the model are described as follows: H=fhy, hs, hal’ is the radial basis vector of the RBF network, and m is the hidden quantity layer;
W = [w:, wa,..., Wo) Tis the RBF network weight vector; B={b1, bs, Du] 7 is the base width vector of the RBF network; CGi=lgp, Cp Cy Cp) 7 is the center vector in the RBF network nodes; in the control process, the RBF network has two inputs: the output of the Pi cortrolier and the grid-connected current.
When the feedback power of the AFE changes suddenly, the RBF network obtains the calculated tracking value through identification, namely: Y{Ki=wi hy +Wohot.
Wmhim There will be a deviation between the tracking value and the grid current.
The gradient descent method is used to update the network output weight Wik) base width vector Bik) node vector Ck) at each moment in real time, and iteratively calculate the new value (Wilk), Bi(k}),Gi{k)) al each moment, the sensitivity information of the grid-connected current to the RBF network is obtained, that is, the Jacobian matrix:
Si EY So {ky = LL CL ulk) halk) =~ Fall) i. 3" Ww { k | A, Cate) uihy dk) TE
Link the Jacobian matrix obtained by the RBF network to the Pl adaptive controller, and the expressions of the parameters K, and K; of the Pl controller can be reached: [Gy = K(f) 8, (8) + 8.0K {k-I}-K,{k-2]] |E; {£) =K{k-}+AK (k} +0, | K(k -1)-K (k-2}] Among them, % is the momentum factor and n is the learning rate.
From this, the expressions of AK, and AK: can be obtained as: 1 > LE Ch {k} CL fe 3] IAK = ge (kj ille (kje (2-1) p pe { } Fi) © { } {A 3 | Pi) i AK, uz ne, { & y Pah) Eo adi) : Then the output of the Pl regulator is: kade 1+ Ke lk) + KE Le (ky me {4 ~1)] After the introduction of adaptive control, the system transfer function becomes: 7 { } G, nv OF {s) \, y LL C+ LOH G, +5{ dd) After the system is adjusted by the Pl adaptive controller, the Kp and Ki parameters are optimized.
When the inverter is working in the first quadrant or the third quadrant, the control center adjusts the adjustable filter unit through the inverter status information.
The tunable filter is used as an input reactor to prevent damage to the inverter caused by the inrush current of the grid.
When the inverter is working in the second quadrant or the fourth quadrant, the adjustable filter unit is used as the feedback current filter unit.
At this time, the adaptive control adjusts the Pl controller parameters (optimized K,, K parameters) adaptively according to the feedback power (RBF neural Network self-learning) of the inverter's steering state and braking stale, so as to reduce the feedback current harmonics of the feedback unit and improve the current quality of the uploading grid.
Compared with the traditional control strategy, the addition of an adaptive adjustment filter greatly improves the adjustment speed. The grid-connecled current ripple is smaller under the conditions of the feedback power of the two feedback units. The Ha {capacitor current feedback coefficient) calculated by the adaptive adjustment can effectively suppress resonance problems, reduce current ripple, make the system run stably, better filler out harmonics, reduce system steady-state errors, increase system stability. And, it can still guarantee high power quality under the condition of sudden changes in the feedback power. It has good dynamic performance.
The adaptive control scheme of this application has the following technical effects: The adjustable filter unit of the present application adopts an integrated design with a built-in regulator, The RBF neural network adaptive control scheme is adopted. After the signal processing of each unit of the frequency converter is adjusted by the control center, the adjustment logic is optimized to adjust the filter.
Compared with the traditional feedback current filter unit, the adjustable filter unit using the adaptive control module based on the RBF neural network has significantly improved response speed when dealing with sudden changes in the power of the feedback unit {refer to Figure 5, Figure 6 and Figure 7). The adjustable filter unit not only reduces the size, but also can be used as the input reactor of the frequency converter under the control logic arrangement, which improves the efficiency of the filter. The heat dissipation of the filler has been significantly improved.
in some special application fields, such as: space-constrained fields, confined space fields that are not easy to dissipate heat, low-speed transmission speed regulation fields, etc.
Due to the resonance frequency of the feedback current filter unit itself, the filtering performance of the harmonic components in the feedback current output by the feedback unit is limited or the harmonic components near the resonance frequency cannot be filtered, and the LVL feedback current filter voltage can only filter out harmonic components higher than the cut-off frequency, but cannot filters out the specified sub-harmonic components.
Therefore, the embodiment of the present application provides a feedback current compensation unit as a backup filter unit.
In an alternative embodiment, the same control center can control multiple frequency converter systems.
The control center includes a comparator that compares the designated sub-harmonics of the respective feedback currents of any two inverter systems.
When the designated sub-harmonics of the feedback currents are the same, the feedback current compensation unit can filter out different harmonic components, and the same designated sub-harmonic components offset each other under the control of the PLL.
For example, when the respective feedback currents of multiple inverters are fed back to the grid at the same time, i any two of the multiple inverters have the same third harmonic but different fifth harmonics, the corresponding feedback current of one inverter can be used.
The compensation unit filters out the harmonic components above the fifth order of the inverter and filters out the harmonic components above the fifth order of the inverter through the corresponding feedback current compensation unit of another inverter, The third harmonics of the two frequency converters cancel each other out under the controlling of the phase-locked loop.
The working principle of the feedback current compensation unit is as follows: the filtered feedback currents ia, is, ic still have harmonic currents, that is, in addition to the sinusoidal fundamental currents las, Is, and ics, there are also harmonic currents In (ie, ian, Inn, ic). In order to prevent the harmonic current from flowing in the power sysiem, a harmonic current compensator is installed.
The main circuit of the harmonic current compensator (HCC) is a three-phase bridge converter with self-shutdown devices.
The converter is connected to the power grid in parallel with the load, so HCC is also called a parallel active power filter.
Perform real-time and appropriate on-off contro! of the 6 switching devices in the converter to make the converter output the second compensation current í to the power grid.
The second compensation current i; is equal to the harmonic current iy, that is, the harmonic current is cancelled by ic, k=i, so the feedback current after removing the harmonic current is las, Isr and icy.
The feedback current compensation unit includes a three-phase bridge converter, When the motor is braking, according to the control signal of the feedback current compensation unit received from the control center, the six switching devices in the three-phase bridge converter are controlled to conduct the real-time turn on/ off control.
The turn-on and turn-off control enables the three-phase bridge converter to generate the second compensation current.
Optionally, when the motor is driven, the stop control signal received from the control center controls the six switching devices in the three-phase bridge converter to turn off, so that the second compensation current is no longer generaied.
Hereinafter, referring to FIG. 8, the control center also includes a harmonic current detection module 802 and a harmonic current control module 804. The harmonic current detection module 802 is used to detect the harmonic components in the feedback current, and includes a current conversion unit 806, a digital low-pass filter 808, a current inverse conversion unit 810, and an addition unit 812, Refer to 8 and 9, the current conversion unit 808 is used to convert the three-phase feedback current into a two-phase orthogonal rotating coordinate system dg io generate a dg axis current, Specifically, the current conversion unit converts the three-phase static variables A, B, and C into two-phase static variables a, B, and then converts the two-phase sialic variables info two-phase rotating variables d, cq: i] = Lg | io] = rg According to the above two formulas, the following formula is determined: 1 1 KH = Cl i] u [cost sincot | 2 toy SZ | lg srs i; sinwt —cosoti 3 0 V3 3 í . 2 2 ja coswt COS (ct _ on) cos (wt + 2x) iq : 3 sinwt sin (ot _— 2x) sin (cot + = H 3 \ 3 iy fag + lan = o. in) ic. dey Tey Refer to Figure 8 and 9, the digital low-pass filter 808 is used to filter the dg-axis harmonic component from the dg-axis current to output the dg-axis DC component.
The digital low-pass filter 808 is used to filter out the harmonic components (lan, ign). in an alternative embodiment, the filtered harmonic components fate=lanations+ignrvions. .., Íqr=lghations+lghztige.. For example, it is possible to filter out the harmonic components above the 5th order and the remaining 3rd harmonic components. Optionally, the harmonic components above the 7th order can be filtered out and the sum of the remaining 3rd and 5th harmonic components is left. In an alternative embodiment, by removing the digital low-pass filter 808 of the g- axis and retaining the digital low-pass filter B08 of the d-axis, the reactive component in the load current can be removed.
Refer to Figure 8 and 3, the current inverse conversion unit 810 is used to convert the dg-axis DC component (optionally, when removing the reactive component in the load current, the d-axis DC component) into the three-phase feedback current three-phase fundamental component. Specifically, the current inverse conversion unit converts two-phase rotating variables d and q into three-phase static variables A, B, and C via two-phase static variables a, §: 100 te I 4 v3 nes 3 i ts |= i fs el [EN WNT 1 V8 Z 2 cost sint | - i (oe — =) sin (ot — Zr) KH AN cos (wt + Zr) sin (oe + x) ’ 3 37) Referring to FIG. 8 and FIG. 9, the addition unit 812 is used to subtract the three- phase fundamental wave component from the three-phase feedback current to obtain the harmonic components in the three-phase feedback current. Specifically, the harmonic components in the three-phase feedback current include the following three or more harmonic components: lan = la la = ag Flan lar? lpn = ig ig = lg Tipp gij len = lelie = le tion le! Use ia, ien, and ich as the command value of the output current of the three-phase bridge converter. When the low-pass filter filters out the harmonic components above the 5th order, the remaining harmonic components after the addition unit are the harmonic components above the 5th order iar-lans, Ístrisns, ion-ions, and the 5th order the above harmonic components iar-lans, leners, lcn-lcns are used as the command value of the output current of the three-phase bridge converter. When the low-pass filter filters out the harmonic components above the 7th order, the remaining harmonic components after the addition unit are the harmonic components above the 7th order ian-ians-ians, Ian-igns-isns, lon-ione- fons, and use the § 7th or more harmonic components lar-lans-lans, isn-igna-isns, ion-ichs-lons as the command value of the output current of the three-phase bridge converter. The current control closed loop is adopted to control the output current of the three- phase bridge converter so that the difference between the output current and the command value of the oulput current is within a preset range.
in an alternative embodiment, the harmonic current detection module 802 further includes a plurality of designated sub-harmonic current detection sub-modules. The following pair uses the designated sub-harmonic current detection sub-module to obtain the 3rd harmonic current and the 5th harmonic current. Each designated sub-harmonic current detection sub-module has the same structure as the harmonic current detection module shown in FIG. 8. For example, compared with the above-mentioned harmonic current detection module B02, the difference between the 3rd, 5th, and 7th harmonic current detection sub-modules is that the first digital low-pass filter, the second digital low-pass filter and the third digital low- pass filter are respectively set to filter cut harmonic components above the 3rd, above 5th, and above 7th. Moreover, the second addition unit of the second digital low-pass filter subtracts the output of the 3rd and 5th harmonic current detection sub-modules io obtain the 3rd harmonic component. The third addition unit of the third digital low-pass filter subtracts the output of the 5th and 7th harmonic current detection sub-modules, and the 5th harmonic component can be obtained. The specified sub-harmonic component can be used as the command valus of the output current of the three-phase bridge converter, and the current control closed loop is used to control the output current of the three-phase bridge converter to make the difference between the output current and the command value of the output current within the preset range. Another specific embodiment of the present invention discloses a motor control method. Refer to Figure 10, the motor control method Includes: step S1002, through the control center to generate the first control signal to the third contro! signal and send them to the regulator; step 51004, when the inverter is working in the first and third quadrants, the rectification of the inverter / the shared inverter unit generates the three-phase AC voltage that drives the motor, and the load current compensation unit removes the harmonic components of the three-phase AC voltage, or the harmonic components and reactive components of the three-phase AC voltage; step 51008, when the inverter works In the second and fourth quadrants, the regulator connects the feedback side reactor and the filter capacitor via the first control signal and the second control signal, so that the filter capacitor, the feedback side reactor and the grid side reactor form a feedback current filter unit io filter out harmonic current in the feedback current; and siep $1008, when the determiner determines that the feedback current filter unit is working abnormally, the regulator is further configured to disconnect the feedback current filter unit via the first control signal and the second control signal, and connects the feedback current compensation unit via the third control signal to offset the harmonic current in the feedback current.
The filtering method of the frequency converter also includes a number of other steps, and the filtering method corresponds to the frequency converter, so in order to avoid redundant description, detailed descriptions of the other steps are omitied. Compared with the prior art, the present invention can achieve at least one of the following advantageous effects:
1. When the inverter works in the second and fourth quadrants, the filter capacitor, the feedback side reactor and the grid side reactor are connected as the feedback current filtering unit through the regulator, so that the feedback current can be filtered out the harmonic components in the feedback current before the feedback current is fed back to the three-phase grid, thereby improving the power quality of the power grid. Optionally, when the determiner determines that the feedback current filter unit is working abnormally, instead of the feedback current filter unit, the feedback current compensation unit generates a harmonic current to offset the harmonic components in the feedback current.
2. The regulator controls each switching device according to the control signal from the control center, so that when the inverter is working in the first and third quadrants, each switching device is disconnected according to the first control signal to the third control signal, so that the grid-side reactor Used as an input reactor to prevent the inverter from being damaged by the inrush current of the grid; and when the inverter is working in the second and fourth quadrants, connect the filter capacitor, the feedback side reactor and the grid side reactor as the feedback current filter unit to filter out the harmonic components in the feedback current.
3. Adopting the adjustable filter unit of the adaptive control module based on the RBF neural network, the response speed of the feedback unit when responding 10 sudden changes in the power of the feedback unit is significantly improved. The adjustable filter unit not only reduces the size, but also can be used as the input reactor of the frequency converter under the control logic arrangement, which improves the efficiency of the filter.
Those skilled in the art can understand that all or part of the procedures for implementing the methods in the above-mentioned embodiments can be completed by instructing relevant hardware through a computer program, and the program can be stored in a compuler-readable storage medium. Wherein, the computer- readable storage medium is a magnetic disk, an optical disk, a read-only siorage memory or a random storage memory, sic.
The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the ari can easily think of changes or changes within the technical scope disclosed in the present invention. All replacements shall be covered within the protection scope of the present invention.

Claims (15)

CONCLUSIECONCLUSION 1. Motorbesturingssysteem met het kenmerk dat het systeem voorzien is van een frequentieomvormer, een regelaar, een besturingscentrum, een netzijdereactor, een terugkoppelingsreactor, een compensatie-eenheid voor laadstroom, en een compensatie-eenheid voor terugkoppelingsstroom, waarbij, De netzijdereactor is elektrisch aangesloten op de regelaar via het eerste in- en uitgangeinde van de regelaar; de terugkoppelingsreactor is elektrisch aangesloten op de regelaar via het tweede in- en uitgang van de regelaar; Het besturingscentrum is aangesloten op de regelaar, via de derde in- en uitgang van de regelaar voor het genereren en het vertrekken van de eerste besturingssignaal t/m de derde besturingssignaal aan de regelaar; De regelaar is voorzien van een filtercondensator, wanneer de frequentieomvormer in het eerste en derde kwadrant werkt, genereert de gelijkrichter/gemeenschappelijke omvormereenheid van de frequentieomvormer een driefasige AC-spanning die de motor aandrijft, de harmonische component van de driefasige AC-spanning wordt verwijderd door de compensatie-eenheid voor laadstroom, of de harmonische component en reactieve component van de driefasige AC-spanning; Wanneer de frequentieomvormer in het tweede en vierde kwadrant werkt, wordt de regelaar op de terugkoppelingsreactor en de filtercondensator aangesloten via het eerste en tweede regelsignaal, zodat de filtercondensator, de terugkoppelingsreactor en de netzijdereactor een filter- eenheid voor terugkoppelingsstroom vormen om de harmonische stroom in de terugkoppelingsstroom uit te filteren; en Het besturingscentrum is voorzien van een discriminator, wanneer de descriminator vaststelt dat de filter-eenheid voor terugkoppelingsstroom abnormaal is, wordt de regelaar gebruikt om de filter-eenheid voor terugkoppelingsstroom uit te schakelen via het eerste en tweede besturingssignaal, en om de compensatie-eenheid voor terugkoppelingsstroom in te schakelen via het derde besturingssignaal voor het compenseren van de harmonische stroom in de terugkoppelingsstroom.1. Motor control system characterized in that the system comprises a frequency converter, a regulator, a control center, a grid-side reactor, a feedback reactor, a charging current compensation unit, and a feedback current compensation unit, wherein, The grid-side reactor is electrically connected to the controller through the first input and output end of the controller; the feedback reactor is electrically connected to the controller via the second input and output of the controller; The control center is connected to the controller through the third input and output of the controller for generating and outputting the first control signal through the third control signal to the controller; The inverter is provided with a filter capacitor, when the frequency converter operates in the first and third quadrant, the rectifier/inverter common unit of the frequency converter generates a three-phase AC voltage that drives the motor, the harmonic component of the three-phase AC voltage is removed by the charging current compensation unit, or the harmonic component and reactive component of the three-phase AC voltage; When the frequency converter operates in the second and fourth quadrants, the regulator is connected to the feedback reactor and the filter capacitor through the first and second control signal, so that the filter capacitor, the feedback reactor and the grid side reactor form a feedback current filter unit to reduce the harmonic current in the filter out feedback stream; and The control center is provided with a discriminator, when the discriminator finds that the feedback current filter unit is abnormal, the controller is used to cut off the feedback current filter unit through the first and second control signal, and to adjust the compensation unit for feedback current to be turned on via the third control signal to compensate for the harmonic current in the feedback current. 2. Motorbesturingssysteem volgens conclusie 1 met het kenmerk dat de frequentieomvormer voorzien is van een terugkoppelingseenheid, waarbij,A motor control system according to claim 1, characterized in that the frequency converter is provided with a feedback unit, wherein, De gelijkrichtereenheid is elektrisch aangesloten op een driefasig elektriciteitsnet om de driefasige netspanning om te zetten in een DC-spanning, waarbij de netspanning een eerste frequentie heeft; De gemeenschappelijke omvormereenheid is elektrisch aangesloten op de gelijkrichtereenheid om de DC-spanning om te zetten naar de driefasige AC- spanning van de tweede freguentie of om de driefasige AC-spanning bij het afremmen van de motor naar de DC-spanning om te zetten; en Het ingangseinde van de terugkoppelingseenheid is aangesloten op het aansluitpunt tussen de gelijkrichtereenheid en gemeenschappelijke omvormereenheid, en het uitgangseinde daarvan is aangesloten op de terugkoppelingsreactor voor het omzetten van de DC-spanning naar de driefasige netspanning om de terugkoppelingsstroom terug te voeren naar het elektriciteitsnet.The rectifier unit is electrically connected to a three-phase power grid to convert the three-phase mains voltage into a DC voltage, the mains voltage having a first frequency; The common inverter unit is electrically connected to the rectifier unit to convert the DC voltage to the three-phase AC voltage of the second frequency or to convert the three-phase AC voltage to the DC voltage when the motor is decelerated; and The input end of the feedback unit is connected to the connection point between the rectifier unit and common inverter unit, and its output end is connected to the feedback reactor for converting the DC voltage to the three-phase mains voltage to return the feedback current to the power grid. 3. Motorbesturingssysteem volgens conclusie 2 met het kenmerk dat: Het ingangseinde van de compensatie-eenheid voor laadstroom is aangesloten op het aansluitpunt, en het uitgangseinde daarvan is aangesloten tussen de gemeenschappelijke omvormereenheid en de motor, voor het genereren van de eerste compensatiestroom bij het genereren van de laadstroom door de gelijkrichter/gemeenschappelijke omvormereenheid, waarbij de amplitude van de eerste compensatiestroom gelijk is aan de amplitude van de harmonische stroom in de laadstroom en de richting van de eerste compensatiestroom tegengesteld is aan de richting van de harmonische stroom in de laadstroom; Het ingangseinde van de compensatie-eenheid voor terugkoppelingsstroom is aangesloten op het aansluitpunt, en het uitgangseinde daarvan is aangesloten op het uitgangseinde van de terugkoppelingseenheid, voor het vertrekken van een tweede compensatiestroom wanneer de filtereenheid voor terugkoppelingsstroom abnormaal is, waarbij de amplitude van de tweede compensatiestroom gelijk is aan de amplitude van de harmonische stroom in de terugkoppelingsstroom en de richting van de tweede compensatiestroom tegengesteld is aan de richting van de harmonische stroom in de terugkoppelingsstroom.The motor control system according to claim 2, characterized in that : The input end of the charging current compensation unit is connected to the terminal, and the output end thereof is connected between the common inverter unit and the motor, for generating the first compensation current in generating of the charging current through the rectifier/common inverter unit, wherein the amplitude of the first compensation current is equal to the amplitude of the harmonic current in the charging current and the direction of the first compensation current is opposite to the direction of the harmonic current in the charging current; The input end of the feedback current compensation unit is connected to the terminal, and its output end is connected to the output end of the feedback unit, for outputting a second compensation current when the feedback current filter unit is abnormal, whereby the amplitude of the second compensation current is equal to the amplitude of the harmonic current in the feedback current and the direction of the second compensation current is opposite to the direction of the harmonic current in the feedback current. 4. Motorbesturingssysteem volgens conclusie 2 met het kenmerk dat het systeem voorzien is van een detectieapparaat voor het eerste signaal, waarbij het detectieapparaat voor het eerste signaal aangesloten is tussen het elektriciteitsnet en de netzijdereactor, voor de real-time detectie van driefasige netspanning en - stroom en voor het vertrekken van de detectiegegevens aan het besturingscentrum via de regelaar.Motor control system according to claim 2, characterized in that the system includes a first signal detecting device, the first signal detecting device being connected between the power grid and the grid side reactor, for the real-time detection of three-phase mains voltage and current and for outputting the detection data to the control center through the controller. 5. Motorbesturingssysteem volgens conclusie 2 met het kenmerk dat: wanneer de descriminator vaststelt dat de harmonische stroom in de driefasige netstroom die door het detectieapparaat voor het eerste signaal gedetecteerd wordt, niet kan gefilterd worden of dat de opgegeven subharmonische stroom niet kan gefilterd worden, werkt de filtereenheid voor de terugkoppelingsstroom abnormaal.A motor control system according to claim 2, characterized in that : when the descriptor determines that the harmonic current in the three-phase mains current detected by the first signal detecting device cannot be filtered or that the specified subharmonic current cannot be filtered, it operates the feedback flow filter unit is abnormal. 6. Motorbesturingssysteem volgens een van de conclusies 1 t/m 5 met het kenmerk dat de abnormale bedrijfsconditie van de filtereenheid voor terugkoppelingsstroom voorzien is van: Abnormale bedrijfsconditie van de netzijdereactor, de terugkoppelingsreactor en/of de filtercondensator; Kortsluiting van de weerstand in de filtereenheid voor de terugkoppelingsstroom die in serie is aangesloten op de filtercondensator; en Dichtbij liggen van de resonantiefrequentie van de filtereenheid voor de terugkoppelingsstroom bij de opgegeven subharmonische frequentie.A motor control system according to any one of claims 1 to 5, characterized in that the abnormal operating condition of the feedback current filter unit comprises: Abnormal operating condition of the grid side reactor, the feedback reactor and/or the filter capacitor; Short circuit of the resistor in the feedback current filter unit connected in series with the filter capacitor; and Close to the resonant frequency of the feedback current filter unit at the specified subharmonic frequency. 7. Motorbesturingssysteem volgens een van de conclusies 2 t/m 5 met het kenmerk dat de regelaar voorzien is van een eerste schakelapparaat, een tweede schakelapparaat en een derde schakelapparaat, waarbij, Het eerste schakelapparaat wordt in- of uitgeschakeld volgens het eerste besturingssignaal om de terugkoppelingsreactor en de netzijdereactor in- of uitgeschakeld; Het tweede schakelapparaat wordt in- of uitgeschakeld volgens het tweede besturingssignaal om de filtercondensator in- of uit te schakelen; en Het derde schakelapparaat wordt in- of uitgeschakeld volgens het derde besturingssignaal dat door de besturingscentrum vertrokken wordt, om de compensatie-eenheid voor terugkoppelingsstroom in- of uit te schakelen.An engine control system according to any one of claims 2 to 5, characterized in that the controller comprises a first switching device, a second switching device and a third switching device, wherein, The first switching device is switched on or off according to the first control signal to control the feedback reactor and the grid-side reactor switched on or off; The second switching device is turned on or off according to the second control signal to turn on or off the filter capacitor; and The third switching device is turned on or off according to the third control signal output from the control center to turn on or off the feedback current compensation unit. 8. Motorbesturingssysteem volgens de conclusies 7 met het kenmerk dat de regelaar wordt ook gebruikt voor:Engine control system according to claim 7, characterized in that the controller is also used for: Wanneer de frequentieomvormer in het eerste en derde kwadrant werkt, worden het eerste schakelapparaat, het tweede schakelapparaat en het derde schakelapparaat uitgeschakeld volgens het eerste besturingssignaal t/m het derde besturingssignaal, zodanig dat de netstroom door de netzijdereactor gefilterd wordt; en Wanneer de frequentieomvormer in het tweede en vierde kwadrant werkt, worden het eerste schakelapparaat en het tweede schakelapparaat ingeschakeld volgens het eerste besturingssignaal en het tweede besturingssignaal, en wordt het derde schakelapparaat uitgeschakeld volgens het derde besturingssignaal, zodanig dat de terugkoppelingsstroom gefilterd wordt door de filtereenheid voor terugkoppelingsstroom die door de filtercondensator, de terugkoppelingsreactor en de netzijdereactor samen gevormd wordt.When the frequency converter is operating in the first and third quadrants, the first switching device, the second switching device and the third switching device are turned off according to the first control signal through the third control signal, so that the mains power is filtered through the mains side reactor; and When the frequency converter is operating in the second and fourth quadrants, the first switching device and the second switching device are turned on according to the first control signal and the second control signal, and the third switching device is turned off according to the third control signal, so that the feedback current is filtered by the filter unit for feedback current formed by the filter capacitor, the feedback reactor and the grid-side reactor together. 9. Motorbesturingssysteem volgens een van de conclusies 8 met het kenmerk dat de regelaar wordt ook gebruikt voor: Wanneer de frequentieomvormer in het tweede en vierde kwadrant werkt, en de filtereenheid voor de terugkoppelingsstroom abnormaal werkt, worden het eerste schakelapparaat en het tweede schakelapparaat uitgeschakeld volgens het eerste besturingssignaal en het tweede besturingssignaal, en wordt het derde schakelapparaat ingeschakeld volgens het derde besturingssignaal, om de harmonische stroom in de terugkoppelingsstroom te compenseren door de compensatie-eenheid voor de terugkoppelingsstroom.A motor control system according to any one of claims 8, characterized in that the controller is also used for: When the frequency converter operates in the second and fourth quadrants, and the feedback current filter unit operates abnormally, the first switching device and the second switching device are turned off according to the first control signal and the second control signal, and the third switching device is turned on according to the third control signal, to compensate for the harmonic current in the feedback current by the feedback current compensation unit. 10. Motorbesturingssysteem volgens de conclusies 7 met het kenmerk dat het besturingscentrum voorzien is van een AFE-besturingseenheid, waarbij de AFE- besturingseenheid voorzien is van: Pl adaptieve besturingsmodule die gebruikt wordt als de controller van het omvormersysteem van de frequentieomvormer om de terugkoppelingseenheid te regelen; en RBF zelf-updatende module van het neutrale netwerk wordt gebruikt voor het ontvangen van het uitgangssignaal van de terugkoppelingseenheid en de uitgangssignaal van de Pl adaptieve besturingsmodule, de uitgangssignaal van de RBF zelf-updatende module van het neutrale netwerk wordt vergeleken met de uitgangssignaal van de terugkoppelingseenheid, en vervolgens wordt de gradiënt descent algoritmen toegepast om de uitgangssignaal gewichten van het neutrale netwerk, de basisbreedte vector en de knoop vector op elk moment bij te werken, de Jacobi-matrix wordt verkregen volgens de bijgewerkte uitgangssignaal gewichten, de basisbreedte vector en de knoop vector, en de Jacobi-matrix is parallel aangesloten op de adaptieve besturingsmodule om de verhoudingsparameters en integratieparameters van de adaptieve besturingsmodule te optimaliseren.A motor control system according to claim 7, characterized in that the control center includes an AFE control unit, the AFE control unit including: Pl adaptive control module used as the inverter system controller of the frequency converter to control the feedback unit ; and RBF self-update module of the neutral network is used to receive the output signal of the feedback unit and the output signal of the Pl adaptive control module, the output signal of the RBF self-update module of the neutral network is compared with the output signal of the feedback unit, and then the gradient descent algorithms is applied to update the output signal weights of the neutral network, the base width vector and the node vector at any time, the Jacobi matrix is obtained according to the updated output signal weights, the base width vector and the knot vector, and the Jacobi matrix is connected in parallel to the adaptive control module to optimize the ratio parameters and integration parameters of the adaptive control module. 11. Motorbesturingssysteem volgens de conclusies 8 met het kenmerk dat het systeem voorzien is van een tweede signaaldetectieapparaat en een derde signaaldetectieapparaat, waarbij: Het tweede signaaldetectieapparaat is aangesloten tussen de terugkoppelingseenheid en de terugkoppelingsreactor, voor real-time detectie van driefasige terugkoppelingsspanning en —stroom, en voor het vertrekken van detectiegegevens aan het besturingscentrum via de regelaar; en Het derde signaaldetectieapparaat wordt gebruikt voor real-time detectie van de driefasige condensatorstroom en -spanning van de filtercondensator, en voor het vertrekken van detectiegegevens aan het besturingscentrum via de regelaar.An engine control system according to claim 8, characterized in that the system includes a second signal detection device and a third signal detection device, wherein: the second signal detection device is connected between the feedback unit and the feedback reactor, for real-time detection of three-phase feedback voltage and current, and for outputting detection data to the control center through the controller; and The third signal detection device is used for real-time detection of the three-phase capacitor current and voltage of the filter capacitor, and output detection data to the control center through the controller. 12. Motorbesturingssysteem volgens de conclusies 11 met het kenmerk dat het besturingscentrum voorzien is van een ontvangstmodule en een berekeningsmodule, waarbij: De ontvangstmodule wordt gebruikt voor het ontvangen van de driefasige netspanning en -stroom van de regelaar, de driefasige terugkoppelingsspanning en -stroom en de driefasige condensatorstroom en -spanning; en De berekeningsmodule wordt gebruikt voor het verkrijgen van een wiskundig model van de filtereenheid voor de terugkoppelingsstroom volgens de filtereenheid voor de terugkoppelingsstroom, en voor het verkrijgen van een transmissiefunctie van het omvormersysteem voor de frequentieomvormer volgens de wiskundig model, waarbij het omvormersysteem voor de frequentieomvormer een filtereenheid voor de terugkoppelingsstroom, een terugkoppelingseenheid en een AFE- besturingseenheid omvat.An engine control system according to claim 11, characterized in that the control center includes a receiver module and a calculation module, wherein: The receiver module is used to receive the three-phase mains voltage and current from the controller, the three-phase feedback voltage and current, and the three-phase capacitor current and voltage; and The calculation module is used to obtain a mathematical model of the feedback current filter unit according to the feedback current filter unit, and to obtain a transmission function of the frequency converter drive system according to the mathematical model, where the frequency converter drive system has a filter unit for the feedback stream, a feedback unit and an AFE control unit. 13. Motorbesturingssysteem volgens de conclusies 3 met het kenmerk dat het besturingscentrum voorzien is van een eerste detectiemodule voor harmonische stroom, een eerste besturingsmodule voor harmonische stroom, een tweede detectiemodule voor harmonische stroom en een tweede besturingsmodule voor harmonische stroom, waarbij: De eerste detectiemodule voor harmonische stroom wordt gebruikt voor het detecteren van de harmonische component in de laadstroom of de harmonische component en reactieve component, de tweede detectiemodule voor harmonische stroom wordt gebruikt voor het detecteren van de harmonische component van de terugkoppelingsstroom, en elk van de eerste detectiemodule voor harmonische stroom en de tweede detectiemodule voor harmonische stroom omvat een stroomconversie-eenheid, een laagdoorlaatfilter, een stroominversieconversie-The motor control system according to claim 3, characterized in that the control center comprises a first harmonic current detection module, a first harmonic current control module, a second harmonic current detection module and a second harmonic current control module, wherein: the first harmonic current detection module harmonic current is used to detect the harmonic component in the load current or the harmonic component and reactive component, the second harmonic current detection module is used to detect the harmonic component of the feedback current, and each of the first harmonic current detection module and the second harmonic current detection module comprises a current conversion unit, a low-pass filter, a current inversion conversion eenheid en een opteleenheid, waarbij:unit and an addition unit, where: De stroomconversie-eenheid wordt gebruikt voor het omzetten van een driefasige laadstroom of een driefasige terugkoppelingsstroom naar een dg-as van een tweefasig orthogonaal draaiend coördinatensysteem om een dq-asstroom te genereren;The power conversion unit is used to convert a three-phase load current or a three-phase feedback current to a dg axis of a two-phase orthogonal rotating coordinate system to generate a dq axis current; De digitale laagdoorlaatfilter wordt gebruikt voor het filteren van de dq-as harmonische component uit de dg-asstroom, of voor het filteren van de harmonische component en reactieve component van de dg-as om de dg-as DC- component uit te voeren;The digital low-pass filter is used to filter the dq-axis harmonic component from the dg-axis current, or to filter the dg-axis harmonic component and reactive component to output the dg-axis DC component; De stroominversieconversie-eenheid wordt gebruikt voor het omzetten van de dq-The power inversion conversion unit is used for converting the dq- as DC-component naar een driefasige fundamentele component in de driefasige laadstroom of een driefasige fundamentele component in een driefasige terugkoppelingsstroom; en De opteleenheid wordt gebruikt voor het aftrekken van de driefasige fundamentele component van de driefasige laadstroom of de driefasige terugkoppelingsstroom om de harmonische component in de driefasige laadstroom te verkrijgen of om de harmonische component en reactieve component in de driefasige laadstroom te verkrijgen, of om de harmonische component in de driefasige terugkoppelingsstroom te verkrijgen;as DC component to a three-phase fundamental component in the three-phase load current or a three-phase fundamental component in a three-phase feedback current; and The adder is used to subtract the three-phase fundamental component from the three-phase charging current or the three-phase feedback current to obtain the harmonic component in the three-phase charging current or to obtain the harmonic component and reactive component in the three-phase charging current, or to obtain the harmonic component in the three-phase feedback current; De besturingsmodule wordt gebruikt voor de eerste harmonische stroom voor het genereren van het besturingssignaal van de compensatie-eenheid voor de laadstroom volgens de harmonische component van de driefasige laadstroom of de harmonische component en reactieve component van de driefasige laadstroom; en De tweede besturingsmodule wordt gebruikt voor de harmonische stroom voor het genereren van het besturingssignaal van de compensatie-eenheid voor de terugkoppelingsstroom volgens de harmonische component van de driefasige terugkoppelingsstroom.The control module is used for the first harmonic current to generate the control signal of the charging current compensation unit according to the harmonic component of the three-phase charging current or the harmonic component and reactive component of the three-phase charging current; and The second harmonic current control module is used to generate the control signal of the feedback current compensation unit according to the harmonic component of the three-phase feedback current. 14. Motorbesturingssysteem volgens de conclusies 13 met het kenmerk dat: De compensatie-eenheid voor laadstroom voorzien is van een eerste driefasige brugomvormer, waarbij de eerste driefasige brugomvormer de 6-schakelapparaten daarin bestuurt voor real-time geleiding, uitschakelregeling volgens het besturingssignaal van de compensatie-eenheid voor de laadstroom ontvangen van het besturingscentrum zodat de eerste driefasige brugomvormer de eerste compensatiestroom genereert; en De compensatie-eenheid voor terugkoppelingsstroom voorzien is van een tweede driefasige brugomvormer, waarbij de tweede driefasige brugomvormer de 6- schakelapparaten daarin bestuurt voor real-time geleiding, uitschakelregeling volgens het besturingssignaal van de compensatie-eenheid voor de terugkoppelingsstroom ontvangen van het besturingscentrum zodat de tweede driefasige brugomvormer de tweede compensatiestroom genereertThe motor control system according to claim 13, characterized in that : The charging current compensation unit includes a first three-phase bridge converter, the first three-phase bridge converter controlling the 6 switching devices therein for real-time conduction, shutdown control according to the control signal of the compensation unit for the charging current received from the control center so that the first three-phase bridge inverter generates the first compensation current; and The feedback current compensation unit is provided with a second three-phase bridge converter, the second three-phase bridge converter controlling the 6 switching devices therein for real-time conduction, trip control according to the control signal of the feedback current compensation unit received from the control center so that the second three-phase bridge inverter generates the second compensation current 15. Werkwijze voor motorbesturing met het kenmerk dat de werkwijze de volgende stappen omvat van: Genereren van het eerste besturingssignaal t/m het derde besturingssignaal via het besturingscentrum, en sturen van de signalen naar de regelaar; Wanneer de frequentieomvormer in het eerste en derde kwadrant werkt, genereren van een driefasige AC-spanning die de motor aandrijft, door de gelijkrichter/gemeenschappelijke omvormereenheid van de freguentieomvormer, verwijderen van de harmonische component van de driefasige AC-spanning of de harmonische component en reactieve component van de driefasige AC-spanning door de compensatie-eenheid voor de laadstroom; Wanneer de frequentieomvormer in het tweede en vierde kwadrant werkt, aansluiten van de regelaar op de terugkoppelingsreactor en de filtercondensator via het eerste en tweede besturingssignaal, zodat de filtercondensator, de terugkoppelingsreactor en de netzijdereactor een filtereenheid voor de terugkoppelingsstroom vormen om de harmonische stroom in de terugkoppelingsstroom uit te filteren; en; Wanneer de descriminator vaststelt dat de filtereenheid voor de terugkoppelingsstroom abnormaal is, uitschakelen van de filtereenheid voor de terugkoppelingsstroom door de regelaar via het eerste en tweede besturingssignaal, en inschakelen van de compensatie-eenheid voor de terugkoppelingsstroom door de regelaar via het derde besturingssignaal om de harmonische stroom in de terugkoppelingsstroom te compenseren.A method of motor control, characterized in that the method comprises the steps of: generating the first control signal through the third control signal through the control center, and sending the signals to the controller; When the frequency converter operates in the first and third quadrant, generating a three-phase AC voltage that drives the motor, through the rectifier/common inverter unit of the frequency converter, removing the harmonic component of the three-phase AC voltage or the harmonic component and reactive component of the three-phase AC voltage through the charging current compensation unit; When the frequency converter operates in the second and fourth quadrants, connecting the regulator to the feedback reactor and the filter capacitor through the first and second control signal, so that the filter capacitor, the feedback reactor and the grid side reactor form a feedback current filter unit to reduce the harmonic current in the feedback current to filter out; and; When the descriptor determines that the feedback current filtering unit is abnormal, turning off the feedback current filtering unit by the regulator through the first and second control signals, and turning on the feedback current compensation unit by the regulator through the third control signal to remove the harmonic current in the feedback current.
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