CN113315115B - DC grid-connected structure of multiphase wind power generation system and control method thereof - Google Patents

DC grid-connected structure of multiphase wind power generation system and control method thereof Download PDF

Info

Publication number
CN113315115B
CN113315115B CN202110360796.1A CN202110360796A CN113315115B CN 113315115 B CN113315115 B CN 113315115B CN 202110360796 A CN202110360796 A CN 202110360796A CN 113315115 B CN113315115 B CN 113315115B
Authority
CN
China
Prior art keywords
phase
bridge
grid
capacitor
isolated
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.)
Active
Application number
CN202110360796.1A
Other languages
Chinese (zh)
Other versions
CN113315115A (en
Inventor
杨光源
周诗嘉
辛清明
王振
彭光强
武霁阳
冯雷
徐爽
潘烙
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CSG Electric Power Research Institute
Maintenance and Test Center of Extra High Voltage Power Transmission Co
Original Assignee
CSG Electric Power Research Institute
Maintenance and Test Center of Extra High Voltage Power Transmission Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by CSG Electric Power Research Institute, Maintenance and Test Center of Extra High Voltage Power Transmission Co filed Critical CSG Electric Power Research Institute
Priority to CN202110360796.1A priority Critical patent/CN113315115B/en
Publication of CN113315115A publication Critical patent/CN113315115A/en
Application granted granted Critical
Publication of CN113315115B publication Critical patent/CN113315115B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/10—Parallel operation of dc sources
    • H02J1/12—Parallel operation of dc generators with converters, e.g. with mercury-arc rectifier
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • 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
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • 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
    • H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
    • H02P9/006—Means for protecting the generator by using control
    • 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
    • H02P2101/00—Special adaptation of control arrangements for generators
    • H02P2101/15—Special adaptation of control arrangements for generators for wind-driven turbines
    • 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
    • H02P2103/00—Controlling arrangements characterised by the type of generator
    • H02P2103/20—Controlling arrangements characterised by the type of generator of the synchronous type
    • 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
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/76—Power conversion electric or electronic aspects

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Eletrric Generators (AREA)

Abstract

The application discloses a DC grid-connected structure of a multiphase wind power generation system and a control method thereof, wherein the structure comprises the following components: the device comprises a multiphase permanent magnet synchronous generator, a three-phase bridge type uncontrolled rectifier and an isolated DC/DC converter. The multiphase permanent magnet synchronous generator comprises a plurality of sets of three-phase windings, and each set of three-phase windings is connected to a high-voltage direct current power grid in a cascading way after being transformed by a three-phase bridge type uncontrolled rectifier and an isolated DC/DC converter. The multiphase permanent magnet synchronous generator adopted by the application has the characteristics of high power, high torque and low torque pulsation, and in addition, when a certain phase fails, the multiphase permanent magnet synchronous generator can still output through power reduction, so that the multiphase permanent magnet synchronous generator has good redundancy characteristic; furthermore, the number of switching devices can be effectively reduced and the cost of the wind power generation system can be reduced by adopting a mode of cascading and directly grid-connected after rectification of a single-phase half-bridge rectifier in the isolated DC/DC converter. Therefore, the technical problems that the traditional three-phase motor grid-connected structure is easy to fail, low in fault tolerance and high in cost are solved.

Description

DC grid-connected structure of multiphase wind power generation system and control method thereof
Technical Field
The application relates to the technical field of new energy power generation, in particular to a DC grid-connected structure of a multi-phase wind power generation system and a control method thereof.
Background
Along with the rapid development of economy, the demand of people for electric energy is also expanding, and the traditional fossil energy power generation cannot meet the demand of people, so that new energy power generation is developed greatly all over the world. Wind energy is used as a new energy source with wider coverage, related motor technology is also very mature, and research and application of wind power generation are gradually developed in China.
The traditional wind power generation adopts a common three-phase motor, but 6 torque pulses are generated due to interaction of 5 times of harmonic waves of air gap magnetomotive force and fundamental waves, so that a three-phase motor grid-connected structure is easy to break down, and when a certain phase of the traditional three-phase motor grid-connected structure breaks down, a power generation system cannot continue to run, so that the fault tolerance and reliability of the parallel grid junction of the traditional three-phase motor are lower; and if high-power output is to be realized, a plurality of three-phase motors and transformers are required to be combined, and the number of devices of the traditional single-phase full-bridge uncontrolled rectifier and half-bridge MMC sub-module grid-connected structure is huge, so that the cost of the traditional three-phase motor grid-connected structure is higher.
Disclosure of Invention
The embodiment of the application provides a direct current grid-connected structure of a multi-phase wind power generation system and a control method thereof, which are used for solving the technical problems that the traditional three-phase motor grid-connected structure is easy to fail, low in fault tolerance and high in cost.
In view of this, the first aspect of the present application provides a dc grid-connected structure of a multi-phase wind power generation system, the structure comprising:
the device comprises a multiphase permanent magnet synchronous generator, k/3 three-phase bridge type uncontrolled rectifiers and k/3 isolated DC/DC converters; wherein k is the phase number of the multiphase permanent magnet synchronous generator, and k is an integer multiple of 3;
the multiphase permanent magnet synchronous generator comprises k/3 sets of three-phase windings, and the mutual difference between any two adjacent sets of three-phase windings is 180 degrees/k electric angles;
each set of three-phase windings of the multiphase permanent magnet synchronous generator is respectively connected with the alternating current side of each three-phase bridge type uncontrolled rectifier; the direct-current side positive electrode of the three-phase bridge type uncontrolled rectifier is connected with the positive electrode of the input end of the isolated DC/DC converter, and the direct-current side negative electrode of the three-phase bridge type uncontrolled rectifier is connected with the negative electrode of the input end of the isolated DC/DC converter;
the negative electrode of the output end of each isolated DC/DC converter is connected with the positive electrode of the output end of the adjacent isolated DC/DC converter; and the positive electrode of the output end of the first isolated DC/DC converter is connected with the positive electrode of the high-voltage direct-current power grid, and the negative electrode of the output end of the kth/3 isolated DC/DC converter is connected with the negative electrode of the high-voltage direct-current power grid.
Optionally, the isolated DC/DC converter specifically includes: a single-phase bridge inverter, a plurality of single-phase half-bridge rectifiers and a multi-winding transformer; the primary side of the multi-winding transformer is provided with 1 winding, the secondary side of the multi-winding transformer is provided with n windings, the transformation ratio is 1:1, and n is a positive integer;
the output end of the single-phase bridge inverter is connected with the primary winding of the multi-winding transformer, and the input end of each single-phase half-bridge rectifier is respectively connected with any one winding in the secondary side of the multi-winding transformer one by one;
the input end of the single-phase bridge inverter is connected with the output end of the three-phase bridge uncontrolled rectifier.
Optionally, the single-phase bridge inverter specifically includes: the first IGBT tube, the second IGBT tube, the third IGBT tube and the fourth IGBT tube;
the collector electrodes of the first IGBT tube and the third IGBT tube are connected to serve as the positive electrode of the input end of the isolated DC/DC converter, and the emitter electrodes of the second IGBT tube and the fourth IGBT tube are connected to serve as the negative electrode of the input end of the isolated DC/DC converter;
the emitter of the first IGBT tube is connected with the collector of the second IGBT tube, and the connection point is used as the positive electrode of the output end of the single-phase bridge inverter; and the emitter of the third IGBT tube is connected with the collector of the fourth IGBT tube, and the connecting point is used as the negative electrode of the output end of the single-phase bridge inverter.
Optionally, the single-phase half-bridge rectifier specifically includes: the first capacitor and the second capacitor are connected with the first IGBT tube and the second IGBT tube; wherein the first capacitor and the second capacitor are rated voltage capacitors;
the emitter of the fifth IGBT tube is connected with the collector of the sixth IGBT tube, and the connection point is used as the positive electrode of the input end of the single-phase half-bridge rectifier;
the negative electrode of the first capacitor is connected with the positive electrode of the second capacitor, and the connecting point is used as the negative electrode of the input end of the single-phase half-bridge rectifier;
the collector electrode of the fifth IGBT tube is connected with the positive electrode of the first capacitor, and the connecting point is used as the positive electrode of the output end of the single-phase half-bridge rectifier;
and the emitter of the sixth IGBT tube is connected with the negative electrode of the second capacitor, and the connecting point is used as the negative electrode of the output end of the single-phase half-bridge rectifier.
Optionally, the method further comprises: a first filter capacitor;
and the filter capacitor is connected in parallel with the positive electrode and the negative electrode of the output end of the three-phase bridge type uncontrolled rectifier.
Optionally, the single-phase bridge inverter further comprises: a second filter capacitor;
the second filter capacitor is connected in parallel with the positive electrode and the negative electrode of the input end of the single-phase bridge inverter.
Optionally, when the rated voltage of the high-voltage direct-current power grid is Uhvdc, the number of single-phase half-bridge rectifiers included in each of the isolated DC/DC converters is y, where y=3×uhvdc/(2×k×uc), and UC is the rated voltage of the first capacitor and the second capacitor.
A second aspect of the present application provides a control method for a dc grid-connected structure of a multi-phase wind power generation system, the method including:
s1, calculating a reference rotating speed of the multiphase permanent magnet synchronous generator according to the current wind speed of the environment where the power generation system is located;
s2, calculating based on an output current reference value calculation formula according to the actual rotating speed of the multiphase permanent magnet synchronous generator and the reference rotating speed to obtain an output current reference value of the three-phase bridge type uncontrolled rectifier;
s3, calculating according to the output current reference value and the output current actual value of the three-phase bridge type uncontrolled rectifier based on a duty ratio calculation formula of the single-phase bridge type inverter to obtain the duty ratio of the single-phase bridge type inverter in the isolated DC/DC converter;
s4, calculating an input current reference value of the single-phase half-bridge rectifier according to an actual output voltage of the single-phase half-bridge rectifier and a voltage value of the first capacitor or the second capacitor based on an input current reference value calculation formula of the single-phase half-bridge rectifier;
s5, comparing the input current reference value of the single-phase half-bridge rectifier with the input current actual value of the single-phase half-bridge rectifier through a hysteresis comparator, and outputting a control signal of the single-phase half-bridge rectifier.
Optionally, the output current reference value calculation formula is:
wherein ,Io_ref To output the current reference value k p1 For the proportionality coefficient, k, of the first PI regulator i1 For the integral coefficient of the first PI-regulator,is an integral factor, ω is the actual rotational speed, ω ref Is the reference rotational speed.
Optionally, the duty cycle calculation formula of the single-phase bridge inverter is:
wherein ,Dh Is the duty cycle, k, of the single-phase bridge inverter in the h-th isolated DC/DC converter p2 Is the proportionality coefficient, k, of the second PI regulator i2 Is the integral coefficient of the second PI-regulator,as integral factor, I oh For the actual value of the output current, I oh_ref Is the output current reference value.
From the above technical solutions, the embodiments of the present application have the following advantages:
in the embodiment of the application, a DC grid-connected structure of a multi-phase wind power generation system is provided, and a multi-phase permanent magnet synchronous generator is adopted, so that low-voltage high-power and high-torque output can be realized; the multiphase permanent magnet synchronous generator has more windings, so that when a certain phase fails, the failed phase can be cut off to realize power reduction transmission, and the multiphase permanent magnet synchronous generator has higher fault tolerance and redundancy; and the output torque pulsation of the multiphase permanent magnet synchronous generator is reduced under the action of stator harmonic current, so that the reliability of the system is improved. Further, the isolated DC/DC converter adopted by the application is a single-phase half-bridge rectifier, and compared with the traditional grid-connected structure of the single-phase full-bridge uncontrolled rectifier and the half-bridge MMC submodule, the number of devices is obviously reduced, and the cost is obviously reduced. Therefore, the technical problems that the traditional three-phase motor grid-connected structure is easy to fail, low in fault tolerance and high in cost are solved.
Drawings
Fig. 1 is a schematic structural diagram of a dc grid-connected structure of a multi-phase wind power generation system according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a multiphase permanent magnet synchronous generator line voltage waveform provided in an embodiment of the present application;
FIG. 3 is a grid-connected current waveform diagram of a DC grid-connected structure of the multi-phase wind power generation system provided in the embodiment of the application;
FIG. 4 is a schematic flow chart of a control method for a DC grid-connected structure of a multi-phase wind power generation system according to an embodiment of the present application;
fig. 5 is a control block diagram of a control method of a dc grid-connected structure of a multi-phase wind power generation system according to an embodiment of the present application.
Detailed Description
In order to make the present application solution better understood by those skilled in the art, the following description will clearly and completely describe the technical solution in the embodiments of the present application with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the subject matter of the present application, are intended to be within the scope of the present application.
Referring to fig. 1, a schematic structural diagram of a dc grid-connected structure of a multi-phase wind power generation system is provided in an embodiment of the present application.
An embodiment one of a dc grid-connected structure of a multiphase wind power generation system provided in an embodiment of the present application includes: the device comprises a multiphase permanent magnet synchronous generator, k/3 three-phase bridge type uncontrolled rectifiers and k/3 isolated DC/DC converters; wherein k is the phase number of the multiphase permanent magnet synchronous generator, and k is an integer multiple of 3.
FIG. 2 is a graph of line voltage waveforms of the multiphase permanent magnet synchronous generator, wherein the peak to peak value of the line voltage of the multiphase permanent magnet synchronous generator is about 1950V, the effective value of the line voltage is about 690V, and the voltage frequency is about 3.5Hz when the wind speed is 10m/s of the rated wind speed; when the wind speed is reduced to 9m/s, the peak-to-peak value of the line voltage of the multiphase permanent magnet synchronous generator is about 1745V, the effective value of the line voltage is about 617V, and the voltage frequency is about 3.07Hz.
The multiphase permanent magnet synchronous generator comprises k/3 sets of three-phase windings, and the mutual difference between any two sets of adjacent three-phase windings is 180 degrees/k electric angle.
It should be noted that, as shown in fig. 1, each three phase in the multiphase permanent magnet synchronous generator is a set of windings, k/3 sets of three-phase windings are all provided, and each set of windings is connected to a high-voltage direct current power grid after being cascaded with a three-phase bridge type uncontrolled rectifier and an isolated DC/DC converter. The number k of phases of the multiphase permanent magnet synchronous generator is 18, the number n of single-phase half-bridge rectifiers contained in each isolated DC/DC converter is 4, the rated power of the multiphase permanent magnet synchronous generator is 2MW, and the constant voltage is 690V. Each set of three-phase windings of the multiphase permanent magnet synchronous generator is respectively connected with the alternating current side of each three-phase bridge type uncontrolled rectifier; the direct-current side positive electrode of the three-phase bridge type uncontrolled rectifier is connected with the positive electrode of the input end of the isolated DC/DC converter, and the direct-current side negative electrode is connected with the negative electrode of the input end of the isolated DC/DC converter.
It should be noted that, as shown in fig. 1, DR is a three-phase bridge type uncontrolled rectifier, the left side, i.e. the ac side, of DR is connected to one set of three-phase windings of the multiphase permanent magnet synchronous generator, and the right side, i.e. the positive pole and the negative pole of the output end of the DC side, are respectively connected to the positive pole and the negative pole of the isolated DC/DC converter correspondingly.
The negative electrode of the output end of each isolated DC/DC converter is connected with the positive electrode of the output end of the adjacent isolated DC/DC converter; and the positive electrode of the output end of the first isolated DC/DC converter is connected with the positive electrode of the high-voltage direct-current power grid, and the negative electrode of the output end of the kth/3 isolated DC/DC converter is connected with the negative electrode of the high-voltage direct-current power grid.
Note that, hvdc+ in fig. 1 is the positive electrode of the high-voltage direct-current power grid, and hvdc—is the negative electrode of the high-voltage direct-current power grid. The rated voltage of the high-voltage direct-current power grid is 12kV.
It will be appreciated that the present application includes a plurality of isolated DC/DC converters, each including a positive electrode and a negative electrode, the positive electrode of the first isolated DC/DC converter being connected to hvdc+, the negative electrode being connected to HVDC-, and the positive and negative electrodes of each isolated DC/DC converter being connected in parallel relationship. Thereby obtaining the direct current grid-connected structure of the multiphase wind power generation system.
FIG. 3 is a graph of grid-tie current for a HVDC grid, which is approximately 158A when the wind speed is 10m/s of rated wind speed, and approximately 105A when the wind speed is reduced to 9m/s due to reduced machine side power.
The embodiment of the application provides a DC grid-connected structure of a multi-phase wind power generation system, which comprises the following components: the device comprises a multiphase permanent magnet synchronous generator, a three-phase bridge type uncontrolled rectifier and an isolated DC/DC converter. The multiphase permanent magnet synchronous generator comprises a plurality of sets of three-phase windings, and each set of three-phase windings is connected to a high-voltage direct current power grid in a cascading way after being transformed by a three-phase bridge type uncontrolled rectifier and an isolated DC/DC converter. The multiphase permanent magnet synchronous generator adopted by the application has the characteristics of high power, high torque and low torque pulsation, and in addition, when a certain phase fails, the multiphase permanent magnet synchronous generator can still output through power reduction, so that the multiphase permanent magnet synchronous generator has good redundancy characteristic; furthermore, the number of switching devices can be effectively reduced and the cost of the wind power generation system can be reduced by adopting a mode of cascading and directly grid-connected after rectification of a single-phase half-bridge rectifier in the isolated DC/DC converter. Therefore, the technical problems that the traditional three-phase motor grid-connected structure is easy to fail, low in fault tolerance and high in cost are solved.
Further, based on the first embodiment, the isolated DC/DC converter of the second embodiment of the present application specifically includes: a single-phase bridge inverter, a plurality of single-phase half-bridge rectifiers and a multi-winding transformer; the primary side of the multi-winding transformer is provided with 1 winding, the secondary side of the multi-winding transformer is provided with n windings, the transformation ratio is 1:1, and n is a positive integer; the output end of the single-phase bridge inverter is connected with the primary winding of the multi-winding transformer, and the input end of each single-phase half-bridge rectifier is respectively connected with any one winding in the secondary side of the multi-winding transformer one by one; the input end of the single-phase bridge inverter is connected with the output end of the three-phase bridge uncontrolled rectifier.
It should be noted that, the second embodiment of the present application provides a specific composition and a connection structure of the isolated DC/DC converter. It is understood that the single-phase bridge inverter is connected to the plurality of single-phase half-bridge rectifiers by a multi-winding transformer, wherein the left side, i.e., the primary side, of the multi-winding transformer is the single-phase bridge inverter, and the right side, i.e., the secondary side, of the multi-winding transformer comprises a plurality of windings, and each winding is connected to each single-phase bridge inverter in a one-to-one correspondence.
Further, on the basis of the second embodiment, the single-phase bridge inverter of the third embodiment specifically includes: the first IGBT tube, the second IGBT tube, the third IGBT tube and the fourth IGBT tube; the collector electrodes of the first IGBT tube and the third IGBT tube are connected to serve as the positive electrode of the input end of the isolated DC/DC converter, and the emitter electrodes of the second IGBT tube and the fourth IGBT tube are connected to serve as the negative electrode of the input end of the isolated DC/DC converter; the emitter of the first IGBT tube is connected with the collector of the second IGBT tube, and the connection point is used as the positive electrode of the output end of the single-phase bridge inverter; the emitter of the third IGBT tube is connected with the collector of the fourth IGBT tube, and the connecting point is used as the negative electrode of the output end of the single-phase bridge inverter.
It should be noted that, the third embodiment of the present application provides a specific composition and a connection structure of the single-phase bridge inverter.
Further, on the basis of the second embodiment, the single-phase half-bridge rectifier in the fourth embodiment of the present application specifically includes: the first capacitor and the second capacitor are connected with the first IGBT tube and the second IGBT tube; the first capacitor and the second capacitor are rated voltage capacitors; the emitter of the fifth IGBT tube is connected with the collector of the sixth IGBT tube, and the connection point is used as the positive electrode of the input end of the single-phase half-bridge rectifier; the negative electrode of the first capacitor is connected with the positive electrode of the second capacitor, and the connecting point is used as the negative electrode of the input end of the single-phase half-bridge rectifier; the collector of the fifth IGBT tube is connected with the positive electrode of the first capacitor, and the connection point is used as the positive electrode of the output end of the single-phase half-bridge rectifier; and the emitter of the sixth IGBT tube is connected with the cathode of the second capacitor, and the connecting point is used as the cathode of the output end of the single-phase half-bridge rectifier.
It should be noted that, the fourth embodiment of the present application provides a specific composition and a connection structure of the single-phase half-bridge rectifier. The first capacitor and the second capacitor are 10mF, and the rated voltage UC is 220V.
Further, on the basis of the first embodiment, the dc grid-connected structure of the multi-phase wind power generation system further includes: a first filter capacitor; the filter capacitor is connected in parallel with the positive electrode and the negative electrode of the output end of the three-phase bridge type uncontrolled rectifier.
The first filter capacitor of the present application has a size of 4mF.
Further, on the basis of the second embodiment, the single-phase bridge inverter further includes: a second filter capacitor; the second filter capacitor is connected in parallel with the positive electrode and the negative electrode of the input end of the single-phase bridge inverter.
The second filter capacitor of the present application has a size of 4mF.
Further, on the basis of the fourth embodiment, when the rated voltage of the high-voltage direct-current power grid is U hvdc When the number of the single-phase half-bridge rectifiers in each isolated DC/DC converter is y, wherein y= 3*U hvdc /(2*k*U C )，U C Is the rated voltage of the first capacitor and the second capacitor.
It is understood that the number of single-phase half-bridge rectifiers in the isolated DC/DC converter is determined based on the rated voltages of the first capacitor and the second capacitor, the rated voltage of the high-voltage DC network, and the number of phases of the multiphase permanent magnet synchronous generator.
The foregoing is an embodiment of a dc grid-connected structure of a multi-phase wind power generation system provided in the embodiments of the present application, and the following is an embodiment of a control method of a dc grid-connected structure of a multi-phase wind power generation system provided in the embodiments of the present application.
Referring to fig. 4 and fig. 5, fig. 4 is a schematic flow chart of a control method of a dc grid-connected structure of a multi-phase wind power generation system provided in an embodiment of the present application, and fig. 5 is a control block diagram of a single-phase bridge inverter and a single-phase half-bridge rectifier in the dc grid-connected structure of the multi-phase wind power generation system provided in an embodiment of the present application.
It should be noted that, the control method provided in the embodiment of the present application is used to calculate the duty ratio and the control signal of one single-phase half-bridge rectifier in the grid-connected structure, and is also applicable to the calculation of the duty ratio and the control signal of other single-phase half-bridge rectifiers in the grid-connected structure.
The embodiment of the control method of the direct current grid-connected structure of the multiphase wind power generation system provided by the embodiment of the application comprises the following steps:
step 201, calculating the reference rotating speed of the multiphase permanent magnet synchronous generator according to the current wind speed of the environment where the power generation system is located.
It should be noted that, according to the vane radius R and the optimal tip speed ratio lambda of the multiphase permanent magnet synchronous generator given in the data manual in the embodiment of the application opt Calculating a reference rotational speed omega ref 。
In particular, the method comprises the steps of,where v is the current wind speed of the environment in which the power generation system is located.
Step 202, calculating according to the actual rotating speed and the reference rotating speed of the multiphase permanent magnet synchronous generator based on an output current reference value calculation formula to obtain an output current reference value of the three-phase bridge type uncontrolled rectifier.
The calculation formula of the output current reference value is as follows:
wherein ,Io_ref To output the current reference value k p1 For the proportionality coefficient, k, of the first PI regulator i1 For the integral coefficient of the first PI-regulator,is an integral factor, ω is an actual rotation speed, ω ref Is the reference rotational speed.
It should be noted that, in the embodiment of the present application, the actual rotation speed ω of the multiphase permanent magnet synchronous generator is detected by the rotary transformer, and ω is combined with ω ref Making a difference, and passing the result of the difference through a first PI regulator, wherein the output of the first PI regulator is the output current reference value I of the three-phase bridge type uncontrolled rectifier o_ref 。
And 203, calculating according to an output current reference value and an output current actual value of the three-phase bridge type uncontrolled rectifier based on a duty ratio calculation formula of the single-phase bridge type inverter to obtain the duty ratio of the single-phase bridge type inverter in the isolated DC/DC converter.
The duty ratio calculation formula of the single-phase bridge inverter is as follows:
in the formula,Dh Is the duty cycle, k of a single-phase bridge inverter in an h isolated DC/DC converter p2 Is the proportionality coefficient, k, of the second PI regulator i2 Is the integral coefficient of the second PI-regulator,as integral factor, I oh To output the current reference value I oh_ref Is the actual value of the output current.
It can be understood that the embodiment of the application not only can know the duty ratio of the conduction time of the IGBT tube of the single-phase bridge inverter by calculating the duty ratio of the single-phase bridge inverter, but also can control the switching state of the IGBT tube.
It should be noted that, in the embodiment of the present application, the current transformer detects the actual output current I of the three-phase bridge type uncontrolled rectifier oh Will I oh And I oh_ref Making a difference, and passing the result of the difference through a second PI regulator, wherein the output of the second PI regulator is the duty ratio D of a single-phase bridge inverter in the h-th isolated DC/DC converter h 。
Step 204, calculating an input current reference value of the single-phase half-bridge rectifier according to the actual output voltage of the single-phase half-bridge rectifier and the voltage value of the first capacitor or the second capacitor based on the input current reference value calculation formula of the single-phase half-bridge rectifier.
The input current reference value calculation formula of the single-phase half-bridge rectifier is as follows:
in the formula,Iih_x_ref Input current for single-phase half-bridge rectifierReference value k p3 For the scaling factor, k, of the third PI regulator i3 For the integral coefficient of the third PI regulator,as integral factor, U Ch_x Is the x single-phase half-bridge rectifier in the h set of windings, U C For filtering the voltage of the capacitor, θ h_x Is the synchronous phase angle of the input voltage of the x single-phase half-bridge rectifier in the h set of windings.
It should be noted that, in the embodiment of the present application, the actual output voltage U of the x single-phase half-bridge rectifier in the h set of windings is detected by the voltage transformer Ch_x X=1, 2, …, n; then determining the synchronous phase angle theta of the input voltage of the x single-phase half-bridge rectifier in the h set of windings according to the phase-locked loop PLL h_x U is set up Ch_x Divided by 2 and then combined with U C Making a difference, passing the result of the difference through a third PI regulator, and multiplying the output of the third PI regulator by sin theta h_x Obtaining an input current reference value I of an xth single-phase half-bridge rectifier in an h set of windings ih_x_ref 。
Step 205, comparing the input current reference value of the single-phase half-bridge rectifier with the input current actual value of the single-phase half-bridge rectifier by using the hysteresis comparator, and outputting a control signal of the single-phase half-bridge rectifier.
It should be noted that, in the embodiment of the present application, the current transformer detects the actual input current I of the x single-phase half-bridge rectifier in the h set of windings ih_x And then I is carried out ih_x And I ih_x_ref The hysteresis comparator outputs a control signal S of an xth single-phase half-bridge rectifier in an h set of windings h_x 。
The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or apparatus.
It should be understood that in this application, "at least one" means one or more, and "a plurality" means two or more. "and/or" for describing an association relationship of an association object means that there may be three relationships, for example, "a and/or B" may mean: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.
In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical functional division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or all or part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: u disk, mobile hard disk, read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic disk or optical disk, etc.
The above embodiments are merely for illustrating the technical solution of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims (7)

1. A dc grid-connected structure of a multi-phase wind power generation system, comprising: the device comprises a multiphase permanent magnet synchronous generator, k/3 three-phase bridge type uncontrolled rectifiers and k/3 isolated DC/DC converters; wherein k is the phase number of the multiphase permanent magnet synchronous generator, and k is an integer multiple of 3;
the multiphase permanent magnet synchronous generator comprises k/3 sets of three-phase windings, and the mutual difference between any two sets of adjacent three-phase windings is 180 degrees/k electric angles;
each set of three-phase windings of the multiphase permanent magnet synchronous generator is respectively connected with the alternating current side of each three-phase bridge type uncontrolled rectifier; the direct-current side positive electrode of the three-phase bridge type uncontrolled rectifier is connected with the positive electrode of the input end of the isolated DC/DC converter, and the direct-current side negative electrode of the three-phase bridge type uncontrolled rectifier is connected with the negative electrode of the input end of the isolated DC/DC converter;
the negative electrode of the output end of each isolated DC/DC converter is connected with the positive electrode of the output end of the adjacent isolated DC/DC converter; the positive electrode of the output end of the first isolated DC/DC converter is connected with the positive electrode of the high-voltage direct-current power grid, and the negative electrode of the output end of the kth/3 isolated DC/DC converter is connected with the negative electrode of the high-voltage direct-current power grid;
wherein, the isolation type DC/DC converter specifically includes: a single-phase bridge inverter, a plurality of single-phase half-bridge rectifiers and a multi-winding transformer; the primary side of the multi-winding transformer is provided with 1 winding, the secondary side of the multi-winding transformer is provided with n windings, the transformation ratio is 1:1, and n is a positive integer;
the output end of the single-phase bridge inverter is connected with the primary winding of the multi-winding transformer, and the input end of each single-phase half-bridge rectifier is respectively connected with any one winding in the secondary side of the multi-winding transformer one by one;
the input end of the single-phase bridge inverter is connected with the output end of the three-phase bridge type uncontrolled rectifier;
wherein, single-phase half-bridge rectifier specifically includes: the first capacitor and the second capacitor are connected with the first IGBT tube and the second IGBT tube; wherein the first capacitor and the second capacitor are rated voltage capacitors;
the emitter of the fifth IGBT tube is connected with the collector of the sixth IGBT tube, and the connection point is used as the positive electrode of the input end of the single-phase half-bridge rectifier;
the negative electrode of the first capacitor is connected with the positive electrode of the second capacitor, and the connecting point is used as the negative electrode of the input end of the single-phase half-bridge rectifier;
the collector electrode of the fifth IGBT tube is connected with the positive electrode of the first capacitor, and the connecting point is used as the positive electrode of the output end of the single-phase half-bridge rectifier;
the emitter of the sixth IGBT tube is connected with the negative electrode of the second capacitor, and the connecting point is used as the negative electrode of the output end of the single-phase half-bridge rectifier;
when the rated voltage of the high-voltage direct-current power grid is U hvdc When the number of the single-phase half-bridge rectifiers in each isolated DC/DC converter is y, wherein y= 3*U hvdc /(2*k*U C )，U C Is the rated voltage of the first capacitor and the second capacitor.
2. The direct current grid-connected structure of a multi-phase wind power generation system according to claim 1, wherein the single-phase bridge inverter specifically comprises: the first IGBT tube, the second IGBT tube, the third IGBT tube and the fourth IGBT tube;
the collector electrodes of the first IGBT tube and the third IGBT tube are connected to serve as the positive electrode of the input end of the isolated DC/DC converter, and the emitter electrodes of the second IGBT tube and the fourth IGBT tube are connected to serve as the negative electrode of the input end of the isolated DC/DC converter;
the emitter of the first IGBT tube is connected with the collector of the second IGBT tube, and the connection point is used as the positive electrode of the output end of the single-phase bridge inverter; and the emitter of the third IGBT tube is connected with the collector of the fourth IGBT tube, and the connecting point is used as the negative electrode of the output end of the single-phase bridge inverter.
3. The multi-phase wind power generation system dc grid-tie structure according to claim 1, further comprising: a first filter capacitor;
and the filter capacitor is connected in parallel with the positive electrode and the negative electrode of the output end of the three-phase bridge type uncontrolled rectifier.
4. The multi-phase wind power generation system dc grid-tie structure of claim 1, wherein the single-phase bridge inverter further comprises: a second filter capacitor;
the second filter capacitor is connected in parallel with the positive electrode and the negative electrode of the input end of the single-phase bridge inverter.
5. A control method of a dc grid-connected structure of a multi-phase wind power generation system, characterized by being applied to any one of the multi-phase wind power generation system dc grid-connected structures of claims 1 to 4, comprising:
s1, calculating the reference rotating speed of the multiphase permanent magnet synchronous generator according to the current wind speed of the environment where the power generation system is located;
s2, calculating based on an output current reference value calculation formula according to the actual rotating speed of the multiphase permanent magnet synchronous generator and the reference rotating speed to obtain an output current reference value of the three-phase bridge type uncontrolled rectifier;
s3, calculating according to the output current reference value and the output current actual value of the three-phase bridge type uncontrolled rectifier based on a duty ratio calculation formula of the single-phase bridge type inverter to obtain the duty ratio of the single-phase bridge type inverter in the isolated DC/DC converter;
s4, calculating an input current reference value of the single-phase half-bridge rectifier based on an input current reference value calculation formula of the single-phase half-bridge rectifier according to the actual output voltage of the single-phase half-bridge rectifier, the synchronous phase angle of the input voltage of the single-phase half-bridge rectifier and the rated voltage value of the first capacitor or the second capacitor;
s5, comparing the input current reference value of the single-phase half-bridge rectifier with the input current actual value of the single-phase half-bridge rectifier through a hysteresis comparator, and outputting a control signal of the single-phase half-bridge rectifier.
6. The method for controlling a dc grid-connected structure of a multi-phase wind power generation system according to claim 5, wherein the output current reference value calculation formula is:
；
wherein ,for outputting the current reference value, < >>For the scaling factor of the first PI-regulator, +.>For the integral coefficient of the first PI-regulator, +.>For integration factor->For the actual rotational speed +.>Is the reference rotational speed.
7. The method for controlling a dc grid-connected structure of a multi-phase wind power generation system according to claim 5, wherein the duty ratio calculation formula of the single-phase bridge inverter is:
；
wherein ,is the duty cycle of the single-phase bridge inverter in the h-th isolated DC/DC converter,/v->For the scaling factor of the second PI regulator, < >>For the integral coefficient of the second PI-regulator, +.>For integration factor->For the output current actual value, +.>A reference value for the output current;
the input current reference value calculation formula of the single-phase half-bridge rectifier is as follows:
；
in the formula,input current reference value for single-phase half-bridge rectifier, < >>For the scaling factor of the third PI regulator, < ->For the integral coefficient of the third PI-regulator, +.>For integration factor->For the x single-phase half-bridge rectifier in the h set of windings +.>Rated voltage of the first capacitor or the second capacitor, < >>Is the synchronous phase angle of the input voltage of the x single-phase half-bridge rectifier in the h set of windings.
CN202110360796.1A 2021-04-02 2021-04-02 DC grid-connected structure of multiphase wind power generation system and control method thereof Active CN113315115B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110360796.1A CN113315115B (en) 2021-04-02 2021-04-02 DC grid-connected structure of multiphase wind power generation system and control method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110360796.1A CN113315115B (en) 2021-04-02 2021-04-02 DC grid-connected structure of multiphase wind power generation system and control method thereof

Publications (2)

Publication Number Publication Date
CN113315115A CN113315115A (en) 2021-08-27
CN113315115B true CN113315115B (en) 2023-08-08

Family

ID=77372083

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110360796.1A Active CN113315115B (en) 2021-04-02 2021-04-02 DC grid-connected structure of multiphase wind power generation system and control method thereof

Country Status (1)

Country Link
CN (1) CN113315115B (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103280838A (en) * 2013-05-29 2013-09-04 浙江大学 Wind power generation high-voltage direct current grid-connected system based on open coil structure and control method thereof

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106451532B (en) * 2016-09-09 2018-12-11 湖南大学 A kind of multiphase directly-drive permanent magnet wind generating unsteady flow integral system and its control method
CN106452098B (en) * 2016-09-09 2018-08-03 湖南大学 A kind of high-power wind generator system and its control method
CN108092257B (en) * 2018-01-19 2020-04-10 湖南大学 Direct-current grid-connected structure of 18-phase wind driven generator and control method thereof
CN108879773B (en) * 2018-07-19 2021-04-27 湖南大学 Control method of six-phase wind driven generator direct-current grid-connected structure

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103280838A (en) * 2013-05-29 2013-09-04 浙江大学 Wind power generation high-voltage direct current grid-connected system based on open coil structure and control method thereof

Also Published As

Publication number Publication date
CN113315115A (en) 2021-08-27

Similar Documents

Publication Publication Date Title
Yuan et al. A transformer-less high-power converter for large permanent magnet wind generator systems
CN101640423B (en) Generator system for wind power generation and variable speed control method
JP5614565B2 (en) Electrical energy conversion equipment
US9225261B2 (en) Method for use of static inverters in variable energy generation environments
CN103280838B (en) A kind of wind power generation high voltage direct current grid-connected system and control method thereof based on opening winding construction
JP2011514798A (en) Power feedback device
CN102064533A (en) Direct-current overvoltage control system of uncontrollable rectification unit of cascade high-voltage transducer
Abdollahi Pulse doubling in zigzag–connected autotransformer–based 12–pulse ac–dc converter for power quality improvement
Estay et al. Dual-boost-NPC converter for a dual three-phase PMSG wind energy conversion system
CN112217238B (en) Brushless doubly-fed generator system and control method thereof
Saito et al. A single-to three-phase matrix converter for a vector-controlled induction motor
Babu et al. Cascaded two-level inverter-based multilevel static VAr compensator using 12-sided polygonal voltage space vector modulation
Vattuone et al. Open-end-winding PMSG for wind energy conversion system with dual boost NPC converter
CN113315115B (en) DC grid-connected structure of multiphase wind power generation system and control method thereof
CN104378034B (en) The operation control system of brushless ac compound rectifier excitation brshless DC motor
Xu et al. Common-mode voltage reduction for back-to-back two-level converters based on zero-sequence voltage injection
Obeidat et al. Simulation of grid connected HVDC offshore wind farm topolgies
CN202004660U (en) DC (Direct Current) over-voltage control system of rectification unit uncontrolled of high-voltage transducer
CN112832951B (en) 18-phase wind power generation system and control method thereof
Abdalla et al. Variable speed pumped storage based on the use of H-bridge cascaded multilevel converter
Gonzalez et al. Fault-tolerant control of six-phase induction generators in wind energy conversion systems with series-parallel machine-side converters
Liu et al. Remedial strategies of cascaded CSIs-fed dual three-phase PMSM drives under one-phase open-circuit faults
Daniel et al. An improved offshore wind turbine to MVDC grid interface using high frequency resonant isolation and input power factor control
Nithya et al. Design and analysis of new multilevel inverter topology with induction motor load
Qin et al. Considerations of harmonic and torque ripple in a large power doubly salient electro-magnet motor drive

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
GR01 Patent grant
GR01 Patent grant