CN201388185Y - Inner-feed chopper cascade speed control device - Google Patents
Inner-feed chopper cascade speed control device Download PDFInfo
- Publication number
- CN201388185Y CN201388185Y CN200920073831U CN200920073831U CN201388185Y CN 201388185 Y CN201388185 Y CN 201388185Y CN 200920073831 U CN200920073831 U CN 200920073831U CN 200920073831 U CN200920073831 U CN 200920073831U CN 201388185 Y CN201388185 Y CN 201388185Y
- Authority
- CN
- China
- Prior art keywords
- copped wave
- igbt
- control
- parallel
- brachium pontis
- 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.)
- Expired - Fee Related
Links
Images
Abstract
The utility model discloses an inner-feed chopper cascade speed control device which comprises a main circuit consisting of an inner-feed motor and a cascade speed control device as well as a control module, wherein the cascade speed control device comprises a rectification part, a chopping part and an inversion part, the rectification part is a three-phase rectifier bridge, the chopping part is formed by connecting two chopping modules in parallel, each chopping module comprises an inductor, one ends of the inductors are respectively connected with a positive pole of a first diode and one end of a second parallel circuit consisting of a first insulated gate bipolar transistor and second diodes inverse-connected at two ends of a second insulated gate bipolar transistor in parallel, the inversion part is an active inverter comprising an upper bridge arm and a lower bridge arm which are connected in series, the upper bridge arm comprises a third parallel circuit consisting of a third insulated gate bipolar transistor and third diodes inverse-connected at two ends of the third insulated gate bipolar transistor in parallel, the lower bridge arm comprises a silicon controlled transistor, and the control module is used for providing a control signal for controlling the operation of the main circuit. The device can rapidly provide over-current and power-down fault protection.
Description
Technical field
The present invention relates to a kind of interior feedback copped wave cascade speed regulator.
Background technology
China is the very country of shortage of an electric power resource, and is energy-conservation as an important techniques policy, and development and national economy is had far-reaching influence.The One's name is legion that blower fan and water pump are used in national economy all departments divides cloth cover extremely wide, and power consumption is huge.According to statistics, the power consumption of national blower fan and water pump accounts for more than 40% of whole industrial electric weight, and blower fan, water pump generally are in operation and all will carry out Load Regulation, and corresponding flow also will be followed the tracks of adjusting.Traditional control method is the valve opening of regulating inlet or outlet, make the 30%-40% of blower fan, water pump power consumption consume in control valve and pipe network pressure drop, this is a kind of of poor benefits, energy consumption is big, device damage is fast, maintenance capacity is big, operating cost is high backward way, not only caused the huge waste of electric energy, and sizable gap has also been arranged with the economical operation standard.If blower fan, water pump are carried out speed governing, then can obtain good energy-saving effect, increase economic efficiency.More promising high-power speed adjusting technique should be tandem control technology and high-pressure frequency-conversion technology at present, wherein tandem control technology is to realize speed governing from the rotor side, and the high-voltage frequency conversion and speed-adjusting technology is directly to come speed governing from stator side, and both are each has something to recommend him.But less demanding for those speed adjusting performances, high-power blower fan, water pump that speed adjustable range is not wide, tandem control is a kind of both economical feasible speed-regulating scheme.Yet there are shortcomings such as power factor is low, harmonic content is big in traditional cascade adjustable-speed system, and the chopper of the interior feedback copped wave cascade adjustable-speed system of industry spot use at present adopts open loop control mostly, its dynamic property is bad, the rotor rectified current is uncontrollable, over current fault takes place easily, make the reliability of device reduce, these have all influenced tandem control applying in blower fan, load of the pumps speed governing occasion.Based on this; the chopper that the present invention adopts digital signal processor internally to present the copped wave tandem control is carried out digital pair of closed-loop control; and chopper adopts misphase control; reduce the direct current pulsation; its Performance And Reliability is improved; simultaneously traditional active inverter is transformed; adopt full control device IGBT to constitute the last brachium pontis of source inventer; following brachium pontis still adopts half control device thyristor SCR to constitute; so not only can carry out overcurrent protection fast, the problem that exists the thyristor inversion to overturn in the time of can also effectively preventing the locking system electric network power-fail.Therefore adopt new power electronic technology and new topological structure and control method, internally present the chopper of copped wave tandem control and carry out digital pair of closed-loop control, make it acting in conjunction, will make step of cascade adjustable-speed system rising technically in tandem control.
Disclosed patent about cascade speed regulator roughly has following a few class at present:
(1) traditional: this type main circuit topology is mainly by rectification module, inversion module constitutes, and does not have the copped wave module, and its power factor is lower, dc pulse is also big, as the disclosed stator double winding of patent CN02109096.3 internal feedback series speed governing high-tension motor and speed-regulating control device thereof.
(2) open loop control type: though this type main circuit also has the copped wave link, its deficiency is to adopt open loop control, and overcurrent protection takes place easily, and the copped wave link is not to adopt phase shifting control, and the direct current pulsation is big.As patent 02260070 disclosed self-saturation type high frequency chopping AC speed regulator.
(3) closed-loop control type: this type main circuit chopper has closed-loop control, but because its electric current loop adopts two point form ring control that stagnates, and the IGBT switching frequency is fixing, have up to several KHz, switching loss is bigger, it is difficult to dispel the heat.As patent 200710122573 disclosed IGBT inverter middle voltage electromotor chopped mode dual DSP digital governing systems.
(4) inversion stalling protection type: this type prevents that at active inverter DC side series IGBT inversion from overturning; the rear end all adopts IGBT to constitute source inventer, not only controls more complicated, and its cost is than higher; near the high voltage converter cost, therefore on price, do not take advantage.
Summary of the invention
The technical problem to be solved in the present invention provides a kind of interior feedback copped wave cascade speed regulator, and it has the characteristics of quick overcurrent and power down error protection.
For solving the problems of the technologies described above, feedback copped wave cascade speed regulator in of the present invention, comprise main circuit and the control module formed by interior feed machine and cascade speed regulator, interior feed machine comprises stator winding, rotor winding and regulates winding that cascade speed regulator comprises rectifying part, copped wave part and inversion part;
The three-phase commutation bridge of rectifying part for constituting by heavy-duty diode, three-phase commutation bridge receives the electric current from the rotor winding;
The copped wave part is formed in parallel by two copped wave modules, the copped wave module comprises the inductance that is connected to the three-phase commutation bridge output, the other end of inductance is connected to the anodal of first diode respectively and is connected in parallel on an end of second parallel circuits that second diode at the second igbt two ends forms by first igbt and direction, and the other end of parallel circuits is connected to another output of three-phase commutation bridge;
The negative pole of first diode is connected to the positive pole of an electric capacity, and the negative pole of electric capacity is connected to the other end of second parallel circuits;
Inversion partly includes source inventer, active inverter comprises the last brachium pontis and the following brachium pontis of series connection, last brachium pontis comprises three by the 3rd igbt and be connected in reverse parallel in the 3rd parallel circuits that the 3rd diode at the 3rd igbt two ends is formed, the input of three the 3rd parallel circuitss is connected to the negative pole of first diode, following brachium pontis comprises that three inputs are connected to three controllable silicon transistors of going up the 3rd parallel circuits output of brachium pontis respectively, three transistorized outputs of controllable silicon are connected with the negative pole of electric capacity, and the last brachium pontis of active inverter and the tie point of following brachium pontis are linked on the adjusting winding of interior feed machine;
Control module receives from signal of obtaining from interior feed machine near switch and the current signal of partly exporting from copped wave of testing the speed, and the copped wave pulse of the misphase that produces according to two closed loop control algorithms and misphase control method exports the control end of first igbt to, and additional control module also produces control end and the transistorized control end of controllable silicon that the active inversion pulse exports second igbt to.
The characteristics of copped wave cascade speed regulator of the present invention are: (1) two copped wave module adopts misphase control, has improved equivalent switching frequency, has reduced the direct current pulsation; (2) brachium pontis adopts controlled power electronic device igbt (IGBT) on the active inverter; following brachium pontis adopts half control device controllable silicon transistor (SCR) to constitute; can carry out overcurrent protection fast, and fault is overturned in incidental inversion can effectively prevent the locking system electric network power-fail time.
Description of drawings
The present invention is further detailed explanation below in conjunction with accompanying drawing and embodiment:
Fig. 1 is the main circuit connection diagram of of the present invention one concrete interior feedback copped wave cascade speed regulator;
Fig. 2 is the control module schematic diagram of of the present invention one concrete interior feedback copped wave cascade speed regulator;
Fig. 3 is the two closed-loop control schematic diagrames of copped wave of the present invention;
Fig. 4 is the chopper current waveform schematic diagram of tradition control;
Fig. 5 is the chopper current waveform and the synthetic waveform schematic diagram of misphase control of the present invention.
Embodiment
Interior feedback copped wave cascade speed regulator with quick overcurrent and power down error protection of the present invention as depicted in figs. 1 and 2.Fig. 1 is the main circuit schematic diagram of of the present invention one concrete device, and Fig. 2 is the control module schematic diagram of of the present invention one concrete device.Feed machine and cascade speed regulator two parts constituted in main circuit comprised.Wherein interior feed machine is divided into three parts again, and (electric current that flows through is I to stator winding
s), (electric current that flows through is I to the rotor winding
r), (electric current that flows through is I to regulate winding
f).Cascade speed regulator comprises rectifying part, copped wave part and inversion part.Wherein the rectifier in the rectifying part is the three-phase commutation bridge DR that heavy-duty diode constitutes, and its function is that handle is from described rotor winding alternating current I
rBecome direct current.The copped wave part is by 90 ° of (phase difference θ=π/N of two phase differences, here copped wave module N=2) constitutes, the copped wave module comprises the inductance that is connected to three-phase commutation bridge DR one output, the other end of inductance is connected to the anodal of first diode respectively and by first igbt and an end that is connected in reverse parallel in second parallel circuits that second diode at the second igbt two ends forms, the other end of parallel circuits is connected to another output of three-phase commutation bridge; Particularly, a copped wave module in this example comprises inductance L
1, be connected inductance L
1The IGBT1 of the other end, be connected in reverse parallel in the diode D1 at IGBT1 two ends
1Be connected to L equally with its positive pole
1The diode D4 of the other end, the electric current that flows into IGBT1 is i
1Another copped wave module comprises L
2, be connected inductance L
2The IGBT2 of the other end, be connected in reverse parallel in the diode D2 at IGBT2 two ends
1Be connected to L equally with its positive pole
2The diode D6 of the other end, the electric current that flows into IGBT2 is i
2Two copped wave modules are at A, and 2 of B are connected, and wherein A is a separated point, and the B point is a Rendezvous Point.Two copped wave modules are carried out the control of speed current double closed-loop by control module, and carry out misphase control between two copped wave modules, have improved equivalent switching frequency, have reduced the pulsation of switching loss and direct current.Copped wave module rear end is connected in storage capacitor C, and the storage capacitor rear end is connected with source inventer, and promptly the B point is connected to the positive pole of capacitor C.
Inversion partly includes source inventer, and active inverter of the present invention is to go up brachium pontis to comprise that controlled power electronic device IGBT constitutes with the different place of traditional inverter.As shown in Figure 1, IGBT3, IGBT5, IGBT7 constitute the last brachium pontis of source inventer, and two ends reverse parallel connection one diode of each IGBT device, are respectively D3, D5, D7; And descend brachium pontis by controllable silicon transistor SCR4, and SCR6, SCR8 constitutes.The adjusting winding side of feed machine in the last brachium pontis of connecting in the active inverter is connected with 3 of tie point D, the E of following brachium pontis, F, its inverter current is I
f
Control module is used for comprising digital signal processor (dsp controller), programmable logic controller (PLC) and man-machine interface to providing pulse as control signal during the IGBT device of main circuit and the SCR.Wherein dsp controller receives the current signal i that partly exports from copped wave
5With from the signal n that tests the speed and obtain from interior feed machine near switch 101
fThe copped wave pulse PWM1 of the misphase that produces according to two closed loop control algorithms and misphase control method and the control end that PWM2 exports IGBT1 and IGBT2 respectively to, dsp controller also produces active inversion pulse PWM3, PWM5, PWM7 and PUL4, PUL6 in addition, PUL8 exports device IGBT3, IGBT5, IGBT7 and the SCR4 in the active inversion portion device, the control end of SCR6, SCR8 respectively to.PLC partly carries out technology controlling and process according to the information that obtains to copped wave part and inversion from dsp controller, simultaneously when copped wave part or inversion partly abnormal operating state occurs, (being overcurrent, overvoltage or power down etc.), feedback information to dsp controller so that it does not export pulse to copped wave part or inversion part.In the one concrete example, the dsp controller chip can adopt the TMS320LF2407 of Ti company, and PLC can adopt Siemens S200, carries out exchanges data by RS485 between dsp controller and the PLC.
The chopper of tradition tandem control adopts switch control, and copped wave module of the present invention adopts speed, current double closed-loop control, and its pair closed-loop control is illustrated as shown in Figure 3: wherein outer shroud is a speed ring, its given signal U
* n(s) be to set by man-machine interface, feedback signal n
fObtain from interior feed machine near switch by testing the speed, and be sent to speed ring ASR, the output variable i of speed ring through firstorder filter
DC *Be the given signal of electric current loop, the feedback signal i of electric current loop
DC(be the i among Fig. 1
5) be to obtain through hall device from the copped wave module input, be to be sent to electric current loop ACR equally through firstorder filter, the output D of electric current loop is exactly the duty ratio control variables, deliver to the copped wave pulse generator, form and trigger pulsation, and the IGBT that exports in the copped wave module through pulse amplifier carries out break-make control.Wherein in this example, produce the control end that pulse PWM1 exports IGBT1 to according to duty ratio D.Obtain another duty ratio numerical value according to duty ratio D is carried out after misphase is handled in addition, this duty ratio numerical value is delivered to the copped wave pulse generator, produce the control end that exports IGBT2 with the dephased pulse PWM2 of pulse PWM1 to, form the misphase control of copped wave module.Concrete, the phase difference of pulse PWM1 and pulse PWM2 is by the choosing value decision of N, θ=π/N, N=2 here.
Therefore, copped wave module of the present invention is except carrying out the control of speed current double closed-loop, and two choppers also adopt misphase control, can improve equivalent switching frequency like this, reduce the pulsation of switching loss and direct current.Fig. 4 is that traditional chopper carries out the current waveform that copped wave obtains, Fig. 5 adopts misphase to control the current waveform (phase difference is 90 °) of different copped wave modules and two current waveforms synthetic waveform after synthetic, from its synthetic waveform as can be seen, its dc pulse is compared with traditional chopper, equivalent switching frequency is the twice of traditional chopper, so dc pulse is smaller.
Dsp controller is mainly finished: the speed current double closed-loop control algolithm of (1) two copped wave module, the generation of pwm pulse; The misphase control of (2) copped wave module; (3) generation of the control algolithm of active inverter and corresponding pulses; (4) overcurrent, overvoltage etc. require the error protection of rapidity.PLC mainly finishes the technology controlling and process of whole system and the action of corresponding device, comprising the technology controlling and process of system start-up and chopper, and the technology controlling and process of active inverter.In addition, PLC also carries out exchanges data by serial communication with man-machine the meeting, corresponding data is sent to man-machine interface shows, receives the instruction action on the man-machine interface simultaneously.
The thyristor active inversion is adopted in tradition tandem control rear end, therefore it is that voltage natural zero-crossing point turn-offs, in case system's line voltage power down like this, then inversion takes place and overturns fault in dc capacitor voltage and AC network side easily, and thyristor is the half control device, therefore when the inversion overcurrent takes place, can not turn-off immediately, therefore the inversion over current fault takes place easily, damages thyristor.Adopt controllable devices IGBT and go up brachium pontis, when system's electric network power-fail, the IGBT device can turn-off immediately like this, and need not wait until that line voltage natural zero-crossing point just turn-offs, and can prevent effectively that inversion from overturning fault.In addition,, can control IGBT rapidly and turn-off, fast the inverter current fault be protected when dsp controller detects inverter current when excessive.
Claims (3)
1. feedback copped wave cascade speed regulator in a kind, comprise main circuit and the control module formed by interior feed machine and cascade speed regulator, the feed machine comprises stator winding, rotor winding and regulates winding in described, described cascade speed regulator comprises rectifying part, copped wave part and inversion part, it is characterized in that:
The three-phase commutation bridge of described rectifying part for constituting by heavy-duty diode, described three-phase commutation bridge receives the electric current from described rotor winding;
Described copped wave part is formed in parallel by two copped wave modules, described copped wave module comprises the inductance that is connected to described three-phase commutation bridge output, the other end of described inductance is connected to the anodal of first diode respectively and an end of second parallel circuits be made up of first igbt and described second diode that is connected in reverse parallel in the second igbt two ends, and the other end of described parallel circuits is connected to another output of described three-phase commutation bridge;
The negative pole of described first diode is connected to the positive pole of an electric capacity, and the negative pole of described electric capacity is connected to the other end of described second parallel circuits;
Described inversion partly includes source inventer, described active inverter comprises brachium pontis and following brachium pontis, the described brachium pontis of going up comprises three by the 3rd igbt and be connected in reverse parallel in the 3rd parallel circuits that the 3rd diode at described the 3rd igbt two ends is formed, the input of described three the 3rd parallel circuitss is connected to the negative pole of described first diode, described brachium pontis down comprises that three inputs are connected to described three controllable silicon transistors of going up the 3rd parallel circuits output of brachium pontis respectively, described three transistorized outputs of controllable silicon are connected with the negative pole of described electric capacity, and the last brachium pontis of described active inverter and the tie point of following brachium pontis are linked on the adjusting winding of described interior feed machine;
Described control module receives from signal of obtaining near switch feed machine in described and the current signal of partly exporting from described copped wave of testing the speed, and the copped wave pulse of the misphase that produces according to two closed loop control algorithms and misphase control method exports the control end of described first igbt to, and described in addition control module also produces control end and the transistorized control end of described controllable silicon that the active inversion pulse exports described second igbt to.
2. according to the described interior feedback copped wave cascade speed regulator of claim 1, it is characterized in that:
Described control module comprises Digital Signal Processing controller and programmable logic controller (PLC) and man-machine interface;
Described Digital Signal Processing controller receives the current signal partly exported from described copped wave and from the signal that tests the speed and obtain near switch feed machine in described, and export the control end of described first igbt to according to the copped wave pulse that two closed loop control algorithms and misphase control method produce misphase, produce control end and the transistorized control end of described controllable silicon that the active inversion pulse exports described second igbt to simultaneously;
Described Programmable Logic Controller is used to control the technology controlling and process of described copped wave part and the technology controlling and process of described inversion part, described Programmable Logic Controller and described digital signal processor carry out exchanges data by interface, described Programmable Logic Controller carries out exchanges data by serial communication and described man-machine interface, corresponding data are sent to described man-machine interface show, receive the instruction action on the described man-machine interface simultaneously.
3. according to the described interior feedback copped wave cascade speed regulator of claim 1, it is characterized in that: the phase difference of described copped wave pulse is 90 °.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200920073831U CN201388185Y (en) | 2009-04-23 | 2009-04-23 | Inner-feed chopper cascade speed control device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200920073831U CN201388185Y (en) | 2009-04-23 | 2009-04-23 | Inner-feed chopper cascade speed control device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201388185Y true CN201388185Y (en) | 2010-01-20 |
Family
ID=41580730
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200920073831U Expired - Fee Related CN201388185Y (en) | 2009-04-23 | 2009-04-23 | Inner-feed chopper cascade speed control device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201388185Y (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102638222A (en) * | 2012-04-24 | 2012-08-15 | 上海电力学院 | Cascade speed regulation device under fast overcurrent protection of composite chopped wave band |
| CN102647151A (en) * | 2012-04-24 | 2012-08-22 | 上海电力学院 | Cascade speed regulating device for current zero-crossing speed measurement for hardware detection |
| CN103441728A (en) * | 2013-08-12 | 2013-12-11 | 四川极度电控系统制造有限责任公司 | Controlling system and controlling method for IGBT type cascade speed control system active power filter |
| CN107919804A (en) * | 2017-12-20 | 2018-04-17 | 西安中车永电电气有限公司 | A kind of diesel locomotive rectification copped wave phase power module |
| CN109159024A (en) * | 2018-10-24 | 2019-01-08 | 浙江机电职业技术学院 | A kind of medium frequency converter for the driving of internal grinder high-speed electric main shaft |
| CN107919804B (en) * | 2017-12-20 | 2024-04-30 | 西安中车永电电气有限公司 | Rectifying chopper phase power module of diesel locomotive |
-
2009
- 2009-04-23 CN CN200920073831U patent/CN201388185Y/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102638222A (en) * | 2012-04-24 | 2012-08-15 | 上海电力学院 | Cascade speed regulation device under fast overcurrent protection of composite chopped wave band |
| CN102647151A (en) * | 2012-04-24 | 2012-08-22 | 上海电力学院 | Cascade speed regulating device for current zero-crossing speed measurement for hardware detection |
| CN103441728A (en) * | 2013-08-12 | 2013-12-11 | 四川极度电控系统制造有限责任公司 | Controlling system and controlling method for IGBT type cascade speed control system active power filter |
| CN107919804A (en) * | 2017-12-20 | 2018-04-17 | 西安中车永电电气有限公司 | A kind of diesel locomotive rectification copped wave phase power module |
| CN107919804B (en) * | 2017-12-20 | 2024-04-30 | 西安中车永电电气有限公司 | Rectifying chopper phase power module of diesel locomotive |
| CN109159024A (en) * | 2018-10-24 | 2019-01-08 | 浙江机电职业技术学院 | A kind of medium frequency converter for the driving of internal grinder high-speed electric main shaft |
| CN109159024B (en) * | 2018-10-24 | 2023-09-08 | 浙江机电职业技术学院 | Intermediate frequency converter for high-speed electric spindle drive of internal grinding machine |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Kolar et al. | Status of the techniques of three-phase rectifier systems with low effects on the mains | |
| CN201656905U (en) | Speed regulating system of a slip power feedback type asynchronous motor with large power and medium-high voltage | |
| CN101615884A (en) | The cascade speed regulator with high power factor of phase-shifting chopped waves | |
| CN102110990B (en) | Wind power generation system based on reverse loose matrix converter and method thereof | |
| CN101499771A (en) | Frequency-changing speed-regulating driver for energy feedback three phase motor with three phase electric power | |
| WO2011147128A1 (en) | Converting device of electrical energy | |
| US20120025609A1 (en) | Very high efficiency uninterruptible power supply | |
| CN103051281A (en) | High-performance four-quadrant frequency converter | |
| Negahdari et al. | Efficiency enhancement of multiphase electric drives at light-load operation considering both converter and stator copper losses | |
| CN105871212A (en) | Power conversion device applied to high-speed flywheel energy storage system | |
| CN201388185Y (en) | Inner-feed chopper cascade speed control device | |
| Chao et al. | Power decoupling methods for single-phase three-poles AC/DC converters | |
| Chaudhari et al. | A three-phase unity power factor front-end rectifier for AC motor drive | |
| WO2011051096A2 (en) | An ac-dc converter and an inverter | |
| CN104184343B (en) | Silicon controlled rectifier rectification feedback apparatus | |
| CN107482941B (en) | Five-level direct current conversion circuit and generator excitation system comprising same | |
| CN101378244A (en) | High-voltage motor parallel connection chopping and double-inversion speed-governing energy-saving controller | |
| CN103582999A (en) | Apparatus for controlling rotor current in a wound-rotor type induction motor | |
| CN209860804U (en) | Single-phase power supply topological structure based on cascade high-voltage frequency converter | |
| Mukherjee et al. | DC grid interface for the integrated generator–rectifier architecture in wind energy systems | |
| CN102116850A (en) | Device and method for testing rectifier | |
| Salmon et al. | Improving the operation of 3-phase diode rectifiers using an asymmetrical half-bridge DC-link active filter | |
| CN106411149A (en) | Series-compensation-based all-solid-state chopper voltage-regulating circuit and voltage regulating method | |
| US9325273B2 (en) | Method and system for driving electric machines | |
| CN203119838U (en) | High-performance four-quadrant frequency converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100120 Termination date: 20150423 |
|
| EXPY | Termination of patent right or utility model |