CN102832635A - Wind power generation networking control system based on direct driving modulation multi-level converter - Google Patents
Wind power generation networking control system based on direct driving modulation multi-level converter Download PDFInfo
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- CN102832635A CN102832635A CN201110393601XA CN201110393601A CN102832635A CN 102832635 A CN102832635 A CN 102832635A CN 201110393601X A CN201110393601X A CN 201110393601XA CN 201110393601 A CN201110393601 A CN 201110393601A CN 102832635 A CN102832635 A CN 102832635A
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Abstract
The invention discloses a wind power generation networking control system based on a direct driving modulation multi-level converter. The system comprises a direct driving modulation multi-level converter, an A/D (Analog-to-Digital) sampling module and a main control module, wherein one side of the direct driving modulation multi-level converter is connected with a power grid; the other side of the direct driving modulation multi-level converter is connected with the low frequency power transmission line of the wind power generation set after the of a wind power generation set is processed by a boost transformer for carrying out variable speed constant frequency control and power control; the system further comprises a 9*n cascading unit module matrix; the A/D sampling module is connected with the direct driving modulation multi-level converter and is used for acquiring electric parameters of the unit modules; and the main control module is respectively connected with the direct driving modulation multi-level converter and the A/D sampling module and is used for providing a switch action signal of each unit module according to the electric parameters of the A/D sampling module. The system has the advantages that the installation and maintenance are convenient, no filtering equipment is needed, the impact on a power grid is small and convenient to expand, and the requirements on the development of a large-scale wind power generation set are met.
Description
Technical field
The present invention relates to the power technology field, relate in particular to and a kind ofly need not to install additional filter apparatus, electrical network is impacted the wind power-generating grid-connected control system based on the direct driving module multi-level converter little and that be convenient to expand.
Background technology
Along with development of global economy, the development and utilization of new forms of energy receives attention more and more widely.Wind energy, as a kind of regenerative resource that cleans green, its market also develops rapidly.Therefore, wind power-generating grid-connected control system has very high Practical significance.The access technology that is widely used in wind power-generating grid-connected system now mainly contains access of constant-speed and constant-frequency unit and the access of variable speed constant frequency unit.The outlet frequency of wind turbine generator is generally between 12～18HZ, and along with the rising of wind-driven generator pool-size, low-speed generator can't satisfy the requirement of the control of being incorporated into the power networks, and then needs with step-up gear the frequency of generating set to be increased near the power frequency.This has not only increased difficulty of design, also brings great inconvenience to installation and maintenance, and the efficient of unit is also undesirable simultaneously.
In addition; Consider the particularity of China's wind energy turbine set resource distribution, promptly our wind energy resources mainly concentrates on Xinjiang, two corridors, river, Inner Mongol and coastal area, and power consumption mainly concentrates on east China; Middle part and southern areas, the transmission line of the long distance of big capacity requires also to increase.And the impact that wind turbine generator causes electrical network when being incorporated into the power networks is also increasing.Wherein, the blower fan output voltage being transformed to the access grid-connected converter of power frequency is the key equipment of wind power-generating grid-connected control system.At present, converter mainly adopts the topological structure of AC-DC-AC, and this kind complex structure has DC link, and efficient is lower.So addressing the above problem to guarantee wind power-generating grid-connected economy, to move reliably is the task of top priority.
One Chinese patent application number is that 200810220070.2 patent of invention discloses a kind of brushless dual-feedback wind power generator control system based on matrix converter; This system adopts 3 * 3 bidirectional switch matrix converters; One side connects the control winding of brushless double feed generator group, and opposite side inserts electrical network.According to the rotor speed of brushless double feed generator, carry out AC-AC frequency conversion, realize that the output electric energy frequency of power winding is constant, i.e. variable speed constant frequency.But owing to adopt matrix converter, its output harmonic wave is bigger, needs to install filter apparatus additional in grid side.And because the special topological structure of matrix converter, its output-voltage levels is few, and output current is discontinuous, can cause certain impact to electrical network.In addition; This system only relates to the control of being incorporated into the power networks of single wind-driven generator, and development situation just at present, large-scale wind turbine generator be trend institute extremely; If adopt this system applies in large-scale wind turbine generator then need be identical with wind-driven generator quantity matrix converter; This will certainly cause great number of issues such as economy, occupation of land, maintenance, and therefore, this system can not satisfy the growth requirement of large-scale wind generating set.
Summary of the invention
The object of the present invention is to provide a kind of wind power-generating grid-connected control system based on the direct driving module multi-level converter, big to solve installation and maintenance inconvenience and output harmonic wave that existing wind power-generating grid-connected control system exists, need install filter apparatus additional; Output current is discontinuous, impacts electrical network and can not satisfy the technical problem of large-scale wind generating set growth requirement.
For achieving the above object; The present invention provides a kind of wind power-generating grid-connected control system based on the direct driving module multi-level converter, is connected with wind turbine generator with electrical network respectively, comprising: direct driving module multi-level converter, A/D sampling module and master control module; Wherein
Direct driving module multi-level converter one side links to each other with electrical network; Opposite side links to each other with the low frequency power transmission circuit of wind turbine generator behind step-up transformer; In order to carry out variable speed constant frequency control and power control, realize being incorporated into the power networks of safe and reliable economy, it further comprises 9 * n cascade unit module matrix;
The A/D sampling module is connected with the direct driving module multi-level converter, in order to gather the electrical parameter of each unit module;
The master control module is connected with the A/D sampling module with the direct driving module multi-level converter respectively, in order to the electric parameter of gathering according to the A/D sampling module, provides the switch actuating signals of each unit module.
According to the described wind power-generating grid-connected control system of preferred embodiment of the present invention based on the direct driving module multi-level converter; Its 9 * n cascade unit module matrix comprises 9 brachium pontis; Each brachium pontis is formed by a buffering reactor and N unit module cascade; And the cascade brachium pontis is 3 * 3 arrays, and the three-phase input end of a side of array links to each other with electrical network, and the three-phase output end of opposite side links to each other with the low frequency power transmission circuit of wind turbine generator behind the low frequency step-up transformer.
According to the described wind power-generating grid-connected control system based on the direct driving module multi-level converter of preferred embodiment of the present invention, above-mentioned unit module further comprises: H bridge unit, sub-A/D sampling module and sub-control module, wherein,
The single-phase inverter of H bridge unit for building by four IGBT switches and electrochemical capacitor;
Sub-A/D sampling module is connected with H bridge unit, in order to gather capacitance voltage;
Sub-control module is connected with sub-A/D sampling module with H bridge unit respectively, and in order to carry out communication with the master control module, transmission voltage information receives control signal, drives 4 IGBT switches.
According to the described wind power-generating grid-connected control system based on the direct driving module multi-level converter of preferred embodiment of the present invention, its master control module adopts the capacitance voltage balance method output waveform modulation of staircase waveform modulation and sequencing selection.
According to the described wind power-generating grid-connected control system based on the direct driving module multi-level converter of preferred embodiment of the present invention, its master control module is a current source matrix with the equivalence of cascade unit module matrix, and then carries out current closed-loop control.
With respect to prior art, the present invention has the following advantages:
1, this system need not rise to the frequency of wind turbine generator near the power frequency, can save the step-up gear of unit shaft tower top, not only reduces cost, and can also improve reliability of system operation.
2, this system adopts low frequency power transmission can reach longer distance than the power frequency transmission of electricity, and loss is low.
But 3, the lower frequency side frequency of this system's real-time regulated direct driving module multi-level converter is to improve the overall operation efficiency of wind turbine generator.
4, this system can regulate the lower frequency side reactive power flow according to system load flow situation control lower frequency side voltage, satisfies the requirement of system power quality and idle configuration.
5, this system adopts modularized design, is convenient to expand according to different power system capacities, can satisfy the growth requirement of large-scale wind generating set.Simultaneously, Redundancy Design makes and safeguards facility more;
6, compared to two traditional level and 3 flat outputs, this system adopts many level outputs, and its harmonic content significantly reduces, and output current is continuous, so need not install extra filter apparatus additional in the side that is incorporated into the power networks, impacts less to electrical network simultaneously.
Description of drawings
Fig. 1 is the overall structure sketch map that the present invention is based on the wind power-generating grid-connected control system of direct driving module multi-level converter;
Fig. 2 is the structural representation of unit module of the direct driving module multi-level converter of the embodiment of the invention;
Fig. 3 is the control principle figure of the direct driving module multi-level converter of the embodiment of the invention;
Fig. 4 is the equivalent circuit diagram of the direct driving module multi-level converter of the embodiment of the invention.
Embodiment
To combine accompanying drawing to explain wind power-generating grid-connected control system structure and principle that patent of the present invention provides in detail below based on the direct driving module multi-level converter.
See also Fig. 1, a kind of wind power-generating grid-connected control system based on the direct driving module multi-level converter comprises: direct driving module multi-level converter 10, A/D sampling module 20 and master control module 30.Direct driving module multi-level converter 10 1 sides link to each other with electrical network 40, and opposite side links to each other with the low frequency power transmission circuit of wind turbine generator 50 behind step-up transformer, in order to carry out variable speed constant frequency control and power control; Realize being incorporated into the power networks of safe and reliable economy; It comprises 9 * n cascade unit module matrix, and 9 * n cascade unit module matrix comprises 9 brachium pontis, and each brachium pontis is formed by a buffering reactor and N unit module cascade; As shown in the figure; The cascade brachium pontis is 3 * 3 arrays, and the three-phase input end of a side of array links to each other with electrical network 40, and the three-phase output end of opposite side links to each other with the low frequency power transmission circuit of wind turbine generator 50 behind the low frequency step-up transformer.A/D sampling module 20 is connected with direct driving module multi-level converter 10, in order to gather the electrical parameter of each unit module; Master control module 30 is connected with A/D sampling module 20 with direct driving module multi-level converter 10 respectively, in order to the electric parameter of gathering according to A/D sampling module 20, provides the switch actuating signals of each unit module.
Please consult Fig. 2 again, unit module comprises H bridge list 60, sub-control module 70 and sub-A/D sampling module 80.H bridge unit 60 comprises 4 IGBT switches and 1 electrochemical capacitor, connection as shown in the figure, and 4 IGBT switches and 1 electrochemical capacitor are built into a unidirectional inverter.Sub-A/D sampling module 70 is connected with H bridge unit 60, in order to gather capacitance voltage.Sub-control module 80 is connected with sub-A/D sampling module 70 with H bridge unit 60 respectively, and in order to carry out communication with master control module 30, transmission voltage information receives control signal, drives 4 IGBT switches.
Master control module of the present invention adopts the capacitance voltage balance method output waveform modulation of staircase waveform modulation and sequencing selection, and is current source matrix with the equivalence of cascade unit module matrix, controls to carry out current closed-loop.See also Fig. 3; The control algolithm part is a core with the TMS320F2812 high-speed digital signal process chip of the C2000 of TI company series; Its function is to calculate each road modulation signal of direct driving module multi-level converter according to each electrical parameter that the A/D sampling module partly detects, and is incorporated into the power networks and power control.External clock is the crystal oscillator of 30MHZ, to dsp chip clock signal is provided.
Because dsp chip PWM port is less, far can not satisfy the requirement that drives the switch in all cascade module, and the I/O mouth is limited, can't connect all unit modules, so must extra chips carry out pulse distribution and signals collecting.Choose the XC3S400AN chip of the Spartan-3AN of Xilinx company series and accomplish miscellaneous function.Utilize 9 XC3S400AN chips, nine brachium pontis of corresponding direct driving module multi-level converter respectively.Its function is the modulation signal of DSP, carries out the staircase waveform modulation, and carries out balance of voltage control according to each capacitance voltage value of this brachium pontis; Simultaneously with this brachium pontis in all sub-control module communications, accept sample information, transmission of control signals.
The present invention is a current source matrix with the equivalence of cascade unit module matrix, and then carries out current closed-loop control.Please refer to Fig. 4, each bridge arm equivalent of direct driving module multi-level converter is become current source.The grid side three-phase current is respectively I
A1, I
B1, I
C1, wind turbine generator side three-phase current is respectively I
A2, I
B2, I
C3
If the three-phase complete equipilibrium, then the instruction current signal of each equivalent current source is following:
Consider the balance of capacitance voltage, then the active power balance of electrical network and wind turbine generator:
Then the amplitude of three-phase direct-axis current is:
In like manner the amplitude of three crossing shaft currents is:
According to handing over shaft current amplitude and direct-axis current amplitude, can calculate grid side and wind turbine generator side three-phase alternating current amplitude:
Also can obtain the phase difference of three-phase alternating current and voltage:
Composite type (5) can be obtained converter both sides alternating current command value with formula (6):
And can obtain the alternating current command signal of 9 brachium pontis of direct driving module multi-level converter according to formula (1), through staircase waveform modulation and capacitance voltage Balance Control, just can realize being incorporated into the power networks control and power are controlled.
With respect to prior art, the present invention has the following advantages:
1, this system need not rise to the frequency of wind turbine generator near the power frequency, can save the step-up gear of unit shaft tower top, not only reduces cost, and can also improve reliability of system operation.
2, this system adopts low frequency power transmission can reach longer distance than the power frequency transmission of electricity, and loss is low.
But 3, the lower frequency side frequency of this system's real-time regulated direct driving module multi-level converter is to improve the overall operation efficiency of wind turbine generator.
4, this system can regulate the lower frequency side reactive power flow according to system load flow situation control lower frequency side voltage, satisfies the requirement of system power quality and idle configuration.
5, this system adopts modularized design, is convenient to expand according to different power system capacities, can satisfy the growth requirement of large-scale wind generating set.Simultaneously, Redundancy Design makes and safeguards facility more;
6, compared to two traditional level and 3 flat outputs, this system adopts many level outputs, and its harmonic content significantly reduces, and output current is continuous, so need not install extra filter apparatus additional in the side that is incorporated into the power networks, impacts less to electrical network simultaneously.
The above; It only is preferable embodiment of the present invention; Be not that the present invention is done any pro forma restriction; Any content that does not break away from technical scheme of the present invention according to any simple modification, equivalent variations and the modification that technical spirit of the present invention is done above embodiment, all belongs to the scope of technical scheme of the present invention.
Claims (5)
1. the wind power-generating grid-connected control system based on the direct driving module multi-level converter is connected with wind turbine generator with electrical network respectively, it is characterized in that, comprising: direct driving module multi-level converter, A/D sampling module and master control module, wherein,
Said direct driving module multi-level converter one side links to each other with electrical network; Opposite side links to each other with the low frequency power transmission circuit of wind turbine generator behind step-up transformer; In order to carry out variable speed constant frequency control and power control; Realize being incorporated into the power networks of safe and reliable economy, it further comprises 9 * n cascade unit module matrix;
Said A/D sampling module is connected with said direct driving module multi-level converter, in order to gather the electric parameter of said each unit module;
Said master control module is connected with the A/D sampling module with said direct driving module multi-level converter respectively, in order to the electric parameter of gathering according to said A/D sampling module, provides the switch actuating signals of each said unit module.
2. the wind power-generating grid-connected control system based on the direct driving module multi-level converter as claimed in claim 1; It is characterized in that: 9 * n cascade unit module matrix comprises 9 brachium pontis; Each said brachium pontis is formed by a buffering reactor and N unit module cascade; And said cascade brachium pontis is 3 * 3 arrays, and the three-phase input end of a side of said array links to each other with electrical network, and the three-phase output end of opposite side links to each other with the low frequency power transmission circuit of wind turbine generator behind the low frequency step-up transformer.
3. the wind power-generating grid-connected control system based on the direct driving module multi-level converter as claimed in claim 2, it is characterized in that: said unit module further comprises: H bridge unit, sub-A/D sampling module and sub-control module, wherein,
The single-phase inverter of said H bridge unit for building by four IGBT switches and electrochemical capacitor;
Said sub-A/D sampling module is connected with said H bridge unit, in order to gather capacitance voltage;
Said sub-control module is connected with sub-A/D sampling module with said H bridge unit respectively, and in order to carry out communication with said master control module, transmission voltage information receives control signal, drives said 4 IGBT switches.
4. according to claim 1 based on the wind power-generating grid-connected control system of direct driving module multi-level converter, it is characterized in that: said master control module adopts the capacitance voltage balance method output waveform modulation of staircase waveform modulation and sequencing selection.
5. like the said wind power-generating grid-connected control system based on the direct driving module multi-level converter of claim 4, it is characterized in that: said master control module is current source matrix with said cascade unit module matrix equivalence, and then carries out current closed-loop control.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10218285B2 (en) | 2015-10-19 | 2019-02-26 | Siemens Aktiengesellschaft | Medium voltage hybrid multilevel converter and method for controlling a medium voltage hybrid multilevel converter |
| CN109787239A (en) * | 2019-02-27 | 2019-05-21 | 西安交通大学 | Tide model exchanges the alternating iteration tidal current computing method and system of combined hybrid system with multi-frequency |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101051793A (en) * | 2007-05-21 | 2007-10-10 | 哈尔滨九洲电气股份有限公司 | Megawatt direct driving type wind and electric joint-net current transformer |
| CN200976561Y (en) * | 2006-11-24 | 2007-11-14 | 华中科技大学 | Superconducting magnetic energy storage based variable constant frequency dual-fed wind power generator excitation frequency transformer |
| CN201039016Y (en) * | 2007-05-21 | 2008-03-19 | 哈尔滨九洲电气股份有限公司 | Mega W direct drive wind network merging convertor |
| CN101860231A (en) * | 2010-05-20 | 2010-10-13 | 新疆全新环保新技术科技有限公司 | Special tri-level full-power converter set for large power wind-driven generator |
-
2011
- 2011-12-01 CN CN201110393601.XA patent/CN102832635B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN200976561Y (en) * | 2006-11-24 | 2007-11-14 | 华中科技大学 | Superconducting magnetic energy storage based variable constant frequency dual-fed wind power generator excitation frequency transformer |
| CN101051793A (en) * | 2007-05-21 | 2007-10-10 | 哈尔滨九洲电气股份有限公司 | Megawatt direct driving type wind and electric joint-net current transformer |
| CN201039016Y (en) * | 2007-05-21 | 2008-03-19 | 哈尔滨九洲电气股份有限公司 | Mega W direct drive wind network merging convertor |
| CN101860231A (en) * | 2010-05-20 | 2010-10-13 | 新疆全新环保新技术科技有限公司 | Special tri-level full-power converter set for large power wind-driven generator |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10218285B2 (en) | 2015-10-19 | 2019-02-26 | Siemens Aktiengesellschaft | Medium voltage hybrid multilevel converter and method for controlling a medium voltage hybrid multilevel converter |
| CN109787239A (en) * | 2019-02-27 | 2019-05-21 | 西安交通大学 | Tide model exchanges the alternating iteration tidal current computing method and system of combined hybrid system with multi-frequency |
| CN109787239B (en) * | 2019-02-27 | 2020-11-10 | 西安交通大学 | Alternating iteration load flow calculation method and system of load flow model and multi-frequency alternating current series-parallel system |
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Effective date of registration: 20161226 Address after: 223001 science and Technology Industrial Park, Jiangsu, Huaian science and technology road, No. 18 Patentee after: North Jiangsu Institute of Shanghai Jiao Tong University Address before: 800 Dongchuan Road, Shanghai, No. 200240 Patentee before: Shanghai Jiaotong Univ. |