CN113472266A - Motor frequency converter - Google Patents
Motor frequency converter Download PDFInfo
- Publication number
- CN113472266A CN113472266A CN202110575557.8A CN202110575557A CN113472266A CN 113472266 A CN113472266 A CN 113472266A CN 202110575557 A CN202110575557 A CN 202110575557A CN 113472266 A CN113472266 A CN 113472266A
- Authority
- CN
- China
- Prior art keywords
- module
- voltage
- phase
- unit
- igbt
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 claims abstract description 49
- 230000001360 synchronised effect Effects 0.000 claims abstract description 9
- 238000001914 filtration Methods 0.000 claims description 18
- 238000006243 chemical reaction Methods 0.000 claims description 14
- 238000000819 phase cycle Methods 0.000 claims description 12
- 230000033228 biological regulation Effects 0.000 claims description 9
- 239000003990 capacitor Substances 0.000 claims description 7
- 230000001960 triggered effect Effects 0.000 abstract description 2
- 230000006872 improvement Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 102100021624 Acid-sensing ion channel 1 Human genes 0.000 description 4
- 101710099904 Acid-sensing ion channel 1 Proteins 0.000 description 4
- 102100022094 Acid-sensing ion channel 2 Human genes 0.000 description 3
- 101710099902 Acid-sensing ion channel 2 Proteins 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000011161 development Methods 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000001172 regenerating effect Effects 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000004377 microelectronic Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
Classifications
-
- 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
- H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
- H02M1/4208—Arrangements for improving power factor of AC input
-
- 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
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc 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
- H02M7/217—Conversion of ac power input into dc 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
- H02M7/219—Conversion of ac power input into dc 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 in a bridge configuration
-
- 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
-
- 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
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses a motor frequency converter, which comprises: the device comprises a control module, a detection module, a pre-charging module, a rectifying module and an inverting module; when the control module receives an external starting signal, the detection module is triggered to obtain the voltage value and the phase of three-phase power on the power grid side, so that the output voltage and the phase of the frequency converter are synchronous with the power grid, and the pre-charging module is controlled to charge to adjust the voltage of the direct-current bus to a set value; the control module enables the rectifier module to work to output stable direct current, the inverter module converts the direct current into three-phase alternating current to drive a motor connected with the frequency converter to act, the detection module detects the voltage fluctuation of a power grid in real time and adjusts the voltage in real time, the voltage of a direct current bus is stable, the frequency converter can still work normally when the input voltage is low, and the motor is guaranteed to run reliably.
Description
Technical Field
The invention relates to the technical field of motor control, in particular to a motor frequency converter.
Background
The Variable-frequency Drive (VFD) applies frequency conversion technology and microelectronic technology, and is a power control device for controlling the rotating speed of an alternating current motor by changing the frequency mode of a working power supply of the motor. After the 20 th century and the 60 th era, power electronic devices have undergone the development processes of SCR (thyristor), GTO (gate turn-off thyristor), BJT (bipolar power transistor), MOSFET (metal oxide field effect transistor), SIT (static induction transistor), SITH (static induction thyristor), MGT (MOS control transistor), MCT (MOS control thyristor), IGBT (insulated gate bipolar transistor), and HVIGBT (high voltage resistant insulated gate bipolar transistor), and the updating of the devices has promoted the continuous development of power electronic conversion technology. In the beginning of the 20 th century in the 70 th era, research on pulse width modulation, voltage transformation and frequency conversion (PWM-VVVF) speed regulation is broken through, and various optimization algorithms are easily realized by the improvement of microprocessor technology after the 80 th century in the 20 th century. In the middle and later stages of the 20 th century and the 80 th era, the technology of the VVVF frequency converter in developed countries such as America, Japan, Germany, English and the like is put into practical use, and the frequency converter is widely applied to the market.
In a traditional frequency converter control system, high-order harmonics on a direct-current bus are large, and elements of a rear-end inversion part are easy to damage. The direct current bus current is conducted in a single direction, energy feedback is avoided, a brake resistor needs to be configured, and the circuit structure is complex. And the voltage on the direct current side is uncontrollable, so that the power factor is low and the energy loss is large. When the power grid fluctuates, the rectified direct current voltage may be lower than the rated voltage of the motor, so that the motor cannot work normally.
Thus, the prior art has yet to be improved and enhanced.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a frequency converter for an electric motor, which can make the electric motor still work stably when the voltage of the power grid fluctuates.
In order to solve the technical problems, the invention adopts the following technical scheme:
an electric machine frequency converter comprising: the device comprises a control module, a detection module, a pre-charging module, a rectifying module and an inverting module; when the inversion module receives an external starting signal, the control module triggers the detection module to acquire the voltage value and the phase of three-phase power on the power grid side, so that the output voltage and the phase of the frequency converter are synchronous with the power grid, and the pre-charge module is controlled to charge to adjust the voltage of the direct-current bus to a set value; the control module enables the rectifying module to work to output stable direct current, and the inverter module converts the direct current into three-phase alternating current to drive a motor connected with the frequency converter to act.
As an improvement of the invention, the detection module comprises an analog-to-digital conversion unit, a phase sequence detection unit and a power factor regulation unit, wherein the analog-to-digital conversion unit converts three-phase power on a network side into digital quantity and sends the digital quantity to the power factor regulation unit, the phase sequence detection unit detects the phase of the three-phase power on the network side and feeds the phase back to the power factor regulation unit, and the power factor regulation unit regulates output power according to the voltage value and the phase of the three-phase power so as to enable the output voltage and the phase of the frequency converter to be synchronous with a power grid.
As an improvement of the present invention, the phase sequence detecting unit includes a voltage comparator chip, a first operational amplifier, a second operational amplifier, a first diode, a second diode, a first voltage dividing resistor, a second voltage dividing resistor, a third voltage dividing resistor, a fourth voltage dividing resistor and a plurality of pull-down resistors, a pin 6 of the voltage comparator chip is connected to pins 5 and 9 of the voltage comparator chip, connected to the precharge module through the first voltage dividing resistor and the second voltage dividing resistor, and grounded through a pull-down resistor, a pin 7 of the voltage comparator chip is connected to a pin 4 of the voltage comparator chip and a cathode of the first diode, an anode of the first diode is connected to an output terminal of the first operational amplifier and a negative input terminal of the first operational amplifier, a positive input terminal of the first operational amplifier is connected to the precharge module through the third voltage dividing resistor, The positive input end of the second operational amplifier is connected with the negative electrode of the second diode and the 8 th pin of the voltage comparator chip, the output end of the second operational amplifier is connected with the positive electrode of the second diode, and the 1 st pin, the 2 nd pin and the 14 th pin of the voltage comparator chip are connected.
As an improvement of the invention, the rectification module comprises a plurality of first IGBT units and a plurality of first filtering units, and the control module outputs a first switching signal to control the first IGBT units to be alternately conducted to output direct-current voltage through filtering of the first filtering units.
As a further improvement of the present invention, the inverter module includes a plurality of second IGBT units and a plurality of second filtering units, and the control module outputs a second switching signal, and the second switching signal is filtered by the second filtering units to control the second IGBT units to alternately turn on and output a three-phase ac voltage.
As a further improvement of the present invention, the first IGBT unit includes a first IGBT tube and a second IGBT tube, the gate of the first IGBT tube is connected to the control module through a first filter unit, the gate of the second IGBT tube is connected to the control module through another first filter unit, the emitter of the first IGBT tube is connected to the collector of the second IGBT tube and the pre-charge module, and the collector of the first IGBT tube and the emitter of the second IGBT tube are connected to the inverter module.
As a further improvement of the present invention, the second IGBT unit includes a third IGBT tube and a fourth IGBT tube, a gate of the third IGBT tube is connected to the control module through a second filter unit, a gate of the fourth IGBT tube is connected to the control module through another second filter unit, a collector of the third IGBT tube is connected to a collector of the fourth IGBT tube as an output end of the inverter module, and is connected to the external motor, an emitter of the third IGBT tube is connected to a collector of the fourth IGBT tube, and a collector of the third IGBT tube and an emitter of the fourth IGBT tube are connected to the inverter module.
As a further improvement of the present invention, the pre-charging module includes a pre-charging switch unit and a pre-charging unit, and the detection module triggers the pre-charging switch unit to input external three-phase power and charge the pre-charging unit, so that the dc bus voltage is adjusted to a set value.
As a further improvement of the present invention, the pre-charging switch unit includes a first relay and a second relay, one end of the first relay and one end of the second relay are connected to the three-phase input terminal, the other end of the first relay is connected to the detection module, and the other end of the second relay is connected to the pre-charging unit.
As a further improvement of the present invention, the pre-charging unit includes two three-phase filter inductors and a plurality of charging capacitors, the two three-phase filter inductors are connected in series between the second relay and the first IGBT unit, and a common connection end of the two three-phase filter inductors is connected to the detection module and is also grounded through one of the charging capacitors.
Compared with the prior art, the motor frequency converter provided by the invention comprises the following components: the device comprises a control module, a detection module, a pre-charging module, a rectifying module and an inverting module; when the control module receives an external starting signal, the detection module is triggered to obtain the voltage value and the phase of three-phase power on the power grid side, so that the output voltage and the phase of the frequency converter are synchronous with the power grid, and the pre-charging module is controlled to charge to adjust the voltage of the direct-current bus to a set value; the control module enables the rectifier module to work to output stable direct current, the inverter module converts the direct current into three-phase alternating current to drive a motor connected with the frequency converter to act, the detection module detects the voltage fluctuation of a power grid in real time and adjusts the voltage in real time, the voltage of a direct current bus is stable, the frequency converter can still work normally when the input voltage is low, and the motor is guaranteed to run reliably.
Drawings
Fig. 1 is a structural block diagram of a motor frequency converter provided by the invention.
Fig. 2 is a schematic circuit diagram of an over-current detection unit of a detection module in a motor frequency converter provided by the invention.
Fig. 3 is a schematic circuit diagram of a phase sequence detection unit and an analog-to-digital conversion unit of a detection module in a motor frequency converter provided by the invention.
Fig. 4 is a schematic circuit diagram of a power factor adjusting unit of a detection module in a frequency converter of a motor provided by the invention.
Fig. 5 is a schematic circuit diagram of a rectifier module of a detection module in a frequency converter of a motor according to the present invention.
Fig. 6 is a schematic circuit diagram of an inverter module of a detection module in a motor frequency converter according to the present invention.
Fig. 7 is a schematic voltage waveform before and after rectification in the motor frequency converter provided by the invention.
Description of the reference numerals
Phase sequence detection unit 202 of analog-to-digital conversion unit 201 of inversion module 50
Power factor adjusting unit 203 voltage comparator chip U1 first operational amplifier A1 second operational amplifier A2 first diode D1 second diode D2
First voltage-dividing resistor R01, second voltage-dividing resistor R02, third voltage-dividing resistor R03, fourth voltage-dividing resistor R04, pull-down resistor R1, first IGBT unit 501
First IGBT tube V1, second IGBT tube V2, third IGBT tube V3
Fourth IGBT tube V4 pre-charge switch unit 301 pre-charge unit 302
The first relay RX1 and the second relay RX2 three-phase filter inductor L1 charge capacitor C1
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
It will be understood that when an element is referred to as being "on," "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present.
It should be noted that the terms of orientation such as left, right, up and down in the embodiments of the present invention are only relative to each other or are referred to the normal use state of the product, and should not be considered as limiting.
Referring to fig. 1, the motor frequency converter provided by the present invention includes a control module 10, a detection module, a pre-charge module, a rectification module, and an inversion module 50, wherein the detection module, the rectification module, and the inversion module 50 are connected to the control module 10, and the pre-charge module is connected to the detection module 20, the rectification module 40, and a power supply.
When the inverter module 50 receives an external start signal, the control module 10 triggers the detection module 20 to obtain the voltage value and the phase of the three-phase power on the power grid side, so that the output voltage and the phase of the frequency converter are synchronous with the power grid, and the pre-charging module 30 is controlled to charge to adjust the voltage of the direct-current bus to a set value; the control module 10 makes the rectifying module 40 work to output stable direct current, the inverter module 50 converts the direct current into three-phase alternating current to drive the motor connected with the frequency converter to act, the detection module 20 detects the voltage fluctuation of the power grid in real time and adjusts the voltage in real time, so that the voltage of the direct current bus is stable, the frequency converter can still work normally when the input voltage is lower, and the reliable operation of the motor is ensured.
During operation, a starting signal of the frequency converter is obtained by the inverter module 50 to an ASIC2 unit (i.e., an inverter control unit) of the control module 10, and the ASIC2 unit sends the starting signal to an AS IC1 unit (i.e., a rectification control unit) to trigger the detection module 20 to detect the voltage value and the phase of the three-phase voltage at the grid side, so AS to complete grid synchronization, after the grid synchronization is completed, the detection module 20 gives a precharge signal to control the incoming line to control the main relay (i.e., the second relay RX2) in the precharge module 30 to pull in and start precharging, and adjust the dc bus voltage (i.e., the voltage of the rectification module 40) to a set value. After the above process is completed, the output of the inverter module 50 allows operation, and the frequency converter starts to operate normally, so as to ensure that the frequency converter can still operate normally when the input voltage is relatively low.
Referring to fig. 2, fig. 3 and fig. 4 together, in the motor frequency converter provided by the present invention, the detection module 20 includes an analog-to-digital conversion unit 201, a phase sequence detection unit 202 and a power factor adjustment unit 203, where the analog-to-digital conversion unit 201 and the phase sequence detection unit 202 are both connected to the power factor adjustment unit 203, and are configured to perform pulse sampling on an input voltage at a power grid side, send an obtained analog voltage to the analog-to-digital conversion unit 201, and send a digital quantity to an ASIC1 rectification control unit for operation after analog-to-digital conversion, so as to obtain a phase of the power grid voltage.
Specifically, the phase sequence detecting unit 202 detects phases of three-phase power on the grid side (i.e., detects the voltage and the phase of the pre-charging module 30), and feeds the phases back to the power factor adjusting unit 203, the analog-to-digital converting unit 201 converts the three-phase power on the grid side into digital quantities and sends the digital quantities to the power factor adjusting unit 203, and the power factor adjusting unit 203 adjusts output power according to the voltage values and the phases of the three-phase power, so that the output voltage and the phases of the frequency converter are synchronized with the power grid.
The phase sequence detection unit 202 includes a voltage comparator chip U1, a first operational amplifier a1, a second operational amplifier a2, a first diode D1, a second diode D2, a first voltage dividing resistor R01, a second voltage dividing resistor R02, a third voltage dividing resistor R03, a fourth voltage dividing resistor R04, and a plurality of pull-down resistors R1.
The pin 6 of the voltage comparator chip U1 is connected with the pins 5 and 9 of the voltage comparator chip U1, and is also connected with the pre-charging module 30 through a first voltage-dividing resistor R01 and a second voltage-dividing resistor R02, and is also grounded through a pull-down resistor R1, the pin 7 of the voltage comparator chip U1 is connected with the pin 4 of the voltage comparator chip U1 and the cathode of a first diode D1, the anode of the first diode D1 is connected with the output terminal of a first operational amplifier a1 and the negative input terminal of a first operational amplifier a1, the positive input terminal of the first operational amplifier a1 is connected with the pre-charging module 30 through a third voltage-dividing resistor R03 and is also grounded through a pull-down resistor R1, the positive input terminal of the second operational amplifier a2 is connected with the pre-charging module 30 through a fourth voltage-dividing resistor R04 and is also grounded through a pull-down resistor R1, the negative input terminal of the second operational amplifier a2 is connected with the cathode of a second diode D2 and the pin 368 of the voltage comparator chip U1, the output end of the second operational amplifier A2 is connected with the anode of the second diode D2, and the 1 st pin, the 2 nd pin and the 14 th pin of the voltage comparator chip U1 are connected.
The divider resistor is composed of a plurality of resistors connected in series, and is used for adjusting the scale factor of the corresponding operational amplifier, sending the scale factor to the PIC12C508A single chip microcomputer of the power factor adjusting unit 203 for a/D conversion, and then sending the scale factor to the ASIC1 rectification control unit of the control module 10 through the superflow detection unit. The power factor adjusting unit 203 controls, the over-current detecting unit also receives the signal output by the power factor adjusting unit 203 and sends the signal to the ASIC1 rectification control unit, and the ASIC1 rectification control unit controls the working state of the rectification module 40. The control module 10 can adopt a microprocessor of Yingfei Ling SAK-C167CR-LM, and has abundant IO ports, thereby controlling the detection module 20, the inversion module 50 and the rectification module 40.
The model of the voltage comparator chip U1 may be LM339D, the first operational amplifier a1 and the second operational amplifier a2 may be integrated in the MC34074D, and the detection module detects the grid current through the MC14081B logic gate, obtains the voltage, and feeds the voltage back to the power factor adjustment unit 203 to adjust the power. The power factor adjusting unit 203 comprises a LT1248CS power factor correction chip, a CD4060BC trigger chip, a PIC12C508 memory chip and peripheral electronic devices thereof, and the working mode thereof is the prior art, and the invention will not be described in detail.
Referring to fig. 1 and 5, the rectifying module 40 includes a plurality of first IGBT units 501 and a plurality of first filtering units 502, and the control module 10 outputs a first switching signal, and the first switching signal is filtered by the first filtering units 502 to control the first IGBT units 501 to alternately turn on and output a dc voltage. After the pre-charging module 30 is synchronized with the grid voltage, the control module 10 outputs a sine wave pulse width modulation signal to alternately turn on the upper and lower arms of the first IGBT unit 501 according to a program setting timing sequence.
Specifically, the first IGBT unit 501 includes a first IGBT V1 and a second IGBT V2, the gate of the first IGBT V1 is connected to the control module 10 through a first filter unit 502, the gate of the second IGBT V2 is connected to the control module 10 through another first filter unit 502, the emitter of the first IGBT V1 is connected to the collector of the second IGBT V2 and the pre-charge module 30, and the collector of the first IGBT V1 and the emitter of the second IGBT V2 are connected to the inverter module 50.
The number of the first IGBT units 501 and the number of the first filter units 502 are three, and the waveform is as shown in (a) of fig. 7 after a sine waveform is input to the grid side and passes through the rectifier module 40, corresponding to three phases of three-phase voltage. When the grid-side voltage fluctuates, the control module 10 adjusts the duty ratio of the IGBT tube driving signal (i.e., controls the on-time of each IGBT tube to adjust the rectified voltage), so that the dc bus voltage can be kept stable, as shown in (b) of fig. 7.
Referring to fig. 1 and fig. 6, the inverter module 50 includes a plurality of second IGBT units 601 and a plurality of second filtering units 602, and the control module 10 outputs a second switching signal, and the second filtering unit 602 filters the second switching signal to control the second IGBT units 601 to alternately turn on and output a three-phase ac voltage.
The second IGBT unit 601 includes a third IGBT tube V3 and a fourth IGBT tube V4, the gate of the third IGBT tube V3 is connected to the control module 10 through a second filter unit 602, the gate of the fourth IGBT tube V4 is connected to the control module 10 through another second filter unit 602, the emitter of the third IGBT tube V3 is connected to the collector of the fourth IGBT tube V4 and is an output terminal of the inverter module 50, and is connected to the external motor, the emitter of the third IGBT tube V3 is connected to the collector of the fourth IGBT tube V4, and the collector of the third IGBT tube V3 and the emitter of the fourth IGBT tube V4 are connected to the inverter module 50.
The circuit structure of the inversion module 50 is opposite to that of the rectification module 40, and the ASIC2 inversion control unit gives out sine wave pulse width modulation signals, so that the upper bridge arm and the lower bridge arm of each IGBT tube are alternately conducted according to a program set time sequence, direct current output by the rectification module 40 is inverted into three-phase alternating current output, and the three-phase alternating current output controls the operation of a motor.
Referring to fig. 1, the pre-charge module 30 includes a pre-charge switch unit 301 and a pre-charge unit 302, and the detection module 20 triggers the pre-charge switch unit 301 to input external three-phase power and charges the pre-charge unit 302, so that the dc bus voltage is adjusted to a set value.
The pre-charging switch unit 301 comprises a first relay RX1 and a second relay RX2, wherein one end of the first relay RX2 and one end of the second relay RX 3526 are connected with a three-phase input end, the other end of the first relay RX1 is connected with the detection module 20, and the other end of the second relay RX2 is connected with the pre-charging unit 302. The second relay RX2 is a main relay, and when the second relay RX2 is switched on, the three-phase power input of the power grid is charged by the pre-charging unit 302, so that the dc bus voltage rectified by the rectifying module 40 is adjusted to a set value. The first relay RX1 is used to enable the detection module 20 to detect the voltage and phase of the grid in order to adjust the power factor so that the dc bus voltage can be kept stable when the grid-side input voltage fluctuates.
The pre-charging unit 302 includes two three-phase filter inductors L1 and a plurality of charging capacitors C1, the two three-phase filter inductors L1 are connected in series between the second relay RX2 and the first IGBT unit 501, and a common connection terminal of the two three-phase filter inductors L1 is connected to the detection module 20 and is also grounded through a charging capacitor C1.
In summary, the motor frequency converter provided by the invention adopts the self-turn-off device IGBT as the power device, and uses the sinusoidal pulse width modulation technique of the grid-side filtering. Since the voltage and current waveforms at the front end of the rectifier are both filtered into sine waveforms as shown in fig. 7 (a), the phase difference angle between the voltage and current waveforms can be set within a certain range as required to adjust the power factor. The rectified DC bus voltage can be set within a certain range, and when the input voltage of the AC side power grid fluctuates, the DC bus voltage is stable, so that the frequency converter can still work normally when the input voltage is low. And the energy after the motor side braking is returned through the inverter module 50, so that when the voltage of the direct current bus is increased, the phase of the alternating current input current is correspondingly adjusted, the phase of the current is opposite to the phase of the power voltage, the regenerative power generation operation is realized, and the regenerative power is fed back to the alternating current power grid.
The traditional rectification adopts diode rectification or silicon controlled rectifier rectification, although the circuit cost is low, the high-order harmonics on the rectified direct current bus are more, and elements of the inversion part at the rear end are easy to damage.
It should be understood that equivalents and modifications of the technical solution and inventive concept thereof may occur to those skilled in the art, and all such modifications and alterations should fall within the scope of the appended claims.
Claims (10)
1. An electric machine frequency converter, comprising: the device comprises a control module, a detection module, a pre-charging module, a rectifying module and an inverting module; when the inversion module receives an external starting signal, the control module triggers the detection module to acquire the voltage value and the phase of three-phase power on the power grid side, so that the output voltage and the phase of the frequency converter are synchronous with the power grid, and the pre-charge module is controlled to charge to adjust the voltage of the direct-current bus to a set value; the control module enables the rectifying module to work to output stable direct current, and the inverter module converts the direct current into three-phase alternating current to drive a motor connected with the frequency converter to act.
2. The motor frequency converter according to claim 1, wherein the detection module comprises an analog-to-digital conversion unit, a phase sequence detection unit and a power factor regulation unit, the analog-to-digital conversion unit converts three-phase power on the grid side into digital quantity and sends the digital quantity to the power factor regulation unit, the phase sequence detection unit detects the phase of the three-phase power on the grid side and feeds the phase back to the power factor regulation unit, and the power factor regulation unit regulates output power according to the voltage value and the phase of the three-phase power so that the output voltage and the phase of the frequency converter are synchronous with the power grid.
3. The electromechanical transducer according to claim 2, wherein the phase sequence detecting unit comprises a voltage comparator chip, a first operational amplifier, a second operational amplifier, a first diode, a second diode, a first voltage divider resistor, a second voltage divider resistor, a third voltage divider resistor, a fourth voltage divider resistor and a plurality of pull-down resistors, wherein the 6 th pin of the voltage comparator chip is connected with the 5 th pin and the 9 th pin of the voltage comparator chip, is also connected with the precharge module through the first voltage divider resistor and the second voltage divider resistor respectively, and is also connected with the ground through a pull-down resistor, the 7 th pin of the voltage comparator chip is connected with the 4 th pin of the voltage comparator chip and the negative electrode of the first diode, the positive electrode of the first diode is connected with the output end of the first operational amplifier and the negative input end of the first operational amplifier, and the positive input end of the first operational amplifier is connected with the precharge module through the third voltage divider resistor, The positive input end of the second operational amplifier is connected with the negative electrode of the second diode and the 8 th pin of the voltage comparator chip, the output end of the second operational amplifier is connected with the positive electrode of the second diode, and the 1 st pin, the 2 nd pin and the 14 th pin of the voltage comparator chip are connected.
4. The motor frequency converter according to claim 1, wherein the rectification module comprises a plurality of first IGBT units and a plurality of first filtering units, and the control module outputs a first switching signal, and the first switching signal is filtered by the first filtering units to control the first IGBT units to alternately conduct and output a dc voltage.
5. The motor frequency converter according to claim 4, wherein the inverter module comprises a plurality of second IGBT units and a plurality of second filtering units, and the control module outputs a second switching signal which is filtered by the second filtering units to control the second IGBT units to alternately conduct and output a three-phase alternating current voltage.
6. The motor frequency converter according to claim 5, wherein the first IGBT unit comprises a first IGBT tube and a second IGBT tube, the gate pole of the first IGBT tube is connected with the control module through a first filtering unit, the gate pole of the second IGBT tube is connected with the control module through another first filtering unit, the emitter pole of the first IGBT tube is connected with the collector pole of the second IGBT tube and the pre-charging module, and the collector pole of the first IGBT tube and the emitter pole of the second IGBT tube are connected with the inverter module.
7. The motor frequency converter according to claim 6, wherein the second IGBT unit comprises a third IGBT tube and a fourth IGBT tube, the gate pole of the third IGBT tube is connected with the control module through a second filter unit, the gate pole of the fourth IGBT tube is connected with the control module through another second filter unit, the emitter of the third IGBT tube is connected with the collector of the fourth IGBT tube as an output end of the inverter module and connected with an external motor, the emitter of the third IGBT tube is connected with the collector of the fourth IGBT tube, and the collector of the third IGBT tube and the emitter of the fourth IGBT tube are connected with the inverter module.
8. The electromechanical transducer of claim 5, wherein the pre-charge module comprises a pre-charge switch unit and a pre-charge unit, and the detection module triggers the pre-charge switch unit to input external three-phase power and charge the pre-charge unit, so that the DC bus voltage is adjusted to a set value.
9. The frequency converter according to claim 8, wherein the pre-charging switch unit comprises a first relay and a second relay, one end of the first relay and one end of the second relay are connected with the three-phase input end, the other end of the first relay is connected with the detection module, and the other end of the second relay is connected with the pre-charging unit.
10. The electromechanical transducer of claim 9, wherein the pre-charging unit comprises two three-phase filter inductors and a plurality of charging capacitors, the two three-phase filter inductors are connected in series between the second relay and the first IGBT unit, and a common connection terminal of the two three-phase filter inductors is connected to the detection module and is also grounded through a charging capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110575557.8A CN113472266A (en) | 2021-05-26 | 2021-05-26 | Motor frequency converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110575557.8A CN113472266A (en) | 2021-05-26 | 2021-05-26 | Motor frequency converter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113472266A true CN113472266A (en) | 2021-10-01 |
Family
ID=77871427
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110575557.8A Pending CN113472266A (en) | 2021-05-26 | 2021-05-26 | Motor frequency converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113472266A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116298561A (en) * | 2023-02-10 | 2023-06-23 | 常熟天地煤机装备有限公司 | Voltage phase sequence detection system for four-quadrant frequency converter |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101286726A (en) * | 2008-06-12 | 2008-10-15 | 杭州西子孚信科技有限公司 | Driving device for electric machine and control method for driving motor |
| CN101860320A (en) * | 2010-05-19 | 2010-10-13 | 上海中科深江电动车辆有限公司 | Electric automobile motor control circuit with charging function |
| CN102234045A (en) * | 2010-04-28 | 2011-11-09 | 杰佛伦西威自动化科技(上海)有限公司 | Elevator control system provided with controllable rectifier and control method thereof |
| CN106093607A (en) * | 2016-06-14 | 2016-11-09 | 江苏科技大学 | The circuit of testing the phase sequence of a kind of brshless DC motor and detection method |
| US20170170743A1 (en) * | 2015-12-11 | 2017-06-15 | Phase Technologies, Llc | Regenerative variable frequency drive with auxiliary power supply |
| US20210083592A1 (en) * | 2019-09-14 | 2021-03-18 | Peda V Medagam | Voltage doubling variable frequency drive |
-
2021
- 2021-05-26 CN CN202110575557.8A patent/CN113472266A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101286726A (en) * | 2008-06-12 | 2008-10-15 | 杭州西子孚信科技有限公司 | Driving device for electric machine and control method for driving motor |
| CN102234045A (en) * | 2010-04-28 | 2011-11-09 | 杰佛伦西威自动化科技(上海)有限公司 | Elevator control system provided with controllable rectifier and control method thereof |
| CN101860320A (en) * | 2010-05-19 | 2010-10-13 | 上海中科深江电动车辆有限公司 | Electric automobile motor control circuit with charging function |
| US20170170743A1 (en) * | 2015-12-11 | 2017-06-15 | Phase Technologies, Llc | Regenerative variable frequency drive with auxiliary power supply |
| CN106093607A (en) * | 2016-06-14 | 2016-11-09 | 江苏科技大学 | The circuit of testing the phase sequence of a kind of brshless DC motor and detection method |
| US20210083592A1 (en) * | 2019-09-14 | 2021-03-18 | Peda V Medagam | Voltage doubling variable frequency drive |
Non-Patent Citations (1)
| Title |
|---|
| 金一鸣;: "基于TINA-TI的三相交流电源相序判断器的设计", 甘肃水利水电技术, no. 09 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116298561A (en) * | 2023-02-10 | 2023-06-23 | 常熟天地煤机装备有限公司 | Voltage phase sequence detection system for four-quadrant frequency converter |
| CN116298561B (en) * | 2023-02-10 | 2024-01-09 | 常熟天地煤机装备有限公司 | Voltage phase sequence detection system for four-quadrant frequency converter |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2019410616B2 (en) | Charging method for power battery, motor control circuit and vehicle | |
| WO2015165191A1 (en) | Steady state control method for three-phase double-mode inverter | |
| WO2022011833A1 (en) | Three-phase inverter and control method for same | |
| CN109039205B (en) | SiC device current source type double three-phase permanent magnet synchronous motor driving system and method | |
| CN105703689A (en) | High-power brushless doubly-fed machine three-level bidirectional variable-frequency speed regulation system | |
| CN103515979A (en) | Low-cost single-phase integrated energy feedback system | |
| CN113472266A (en) | Motor frequency converter | |
| WO2024051553A1 (en) | Totem-pole pfc circuit and control method therefor, and power source apparatus | |
| CN103269113B (en) | Low-voltage electromobile driving governor and charging method | |
| CN219875518U (en) | Inverter and power supply system | |
| CN205356183U (en) | Electric current source type three -phase inverter topological structure | |
| EP4068610B1 (en) | Converter and on-board charger | |
| CN202841050U (en) | Cascaded high-voltage inverter speed regulating system with energy feedback function | |
| CN203456879U (en) | Low-cost single-phase integrated energy feedback system | |
| CN216851764U (en) | Energy storage type variable frequency transmission device | |
| CN113364334B (en) | Double-parallel Buck-Boost inverter and control method thereof | |
| CN205959943U (en) | Wide power input X -ray tube rotary anode drive arrangement | |
| CN105471338B (en) | The starter of brushless double-fed motor | |
| CN110474527B (en) | Frequency conversion device for correcting three-phase electric power factor, control method thereof and air conditioner | |
| CN105024396A (en) | Energy feedback frequency converter | |
| CN113965139A (en) | Thyristor and IGBT mixed three-phase motor two-phase frequency conversion control circuit and method thereof | |
| CN217037069U (en) | Inverter circuit topological structure for variable frequency speed regulation of two-phase alternating current motor | |
| CN106128926B (en) | A kind of wide power input X ray tube rotary anode drive device and the rotating anode method of control | |
| CN205265573U (en) | Brushless double -fed motor's start structure | |
| CN216959709U (en) | Based on permanent-magnet machine formula centrifugal machine controlling means |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |