WO2018218924A1 - 高压直流发电机、风力发电机组和风电场 - Google Patents

高压直流发电机、风力发电机组和风电场 Download PDF

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Publication number
WO2018218924A1
WO2018218924A1 PCT/CN2017/115420 CN2017115420W WO2018218924A1 WO 2018218924 A1 WO2018218924 A1 WO 2018218924A1 CN 2017115420 W CN2017115420 W CN 2017115420W WO 2018218924 A1 WO2018218924 A1 WO 2018218924A1
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Prior art keywords
generator
direct current
high voltage
voltage direct
phase winding
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PCT/CN2017/115420
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English (en)
French (fr)
Inventor
蒋中川
张世福
郭锐
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北京金风科创风电设备有限公司
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Publication of WO2018218924A1 publication Critical patent/WO2018218924A1/zh

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M7/219—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a bridge configuration
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381—Dispersed generators
    • 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
    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/466—Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
    • H02J3/472—For selectively connecting the AC sources in a particular order, e.g. sequential, alternating or subsets of sources
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/28—The renewable source being wind energy
    • 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

Definitions

  • the present invention relates to the field of generators, and more particularly to a high voltage direct current generator capable of outputting a constant high voltage direct current, a wind power generator including the high voltage direct current generator, and a wind farm.
  • Direct-drive generator sets based on permanent magnet generators usually use large-volume, high-power, low-speed generators.
  • the generator output power usually needs to be transmitted through the tower to the tower bottom power electronic converter, and then connected to the wind farm regional public AC grid via the power frequency transformer.
  • the output of such a generator generally has the following characteristics: low voltage variable voltage, 3-phase alternating current, variable frequency, and the like.
  • a wind farm with multiple such generators will employ an AC grid-connected scheme in which multiple generators are connected to the AC grid via a converter device.
  • the AC grid-connected scheme is currently a relatively mature power grid-connected scheme in the world.
  • its application in wind turbine farms still has some shortcomings.
  • the inertia of the wind turbines express their input to the AC power bus. When large-scale multi-point integration, these inertias will cause complex low-frequency power coupling at the grid-connected terminals, which will easily cause low-frequency problems in the grid.
  • the three-line transmission is used in the wind farm, and the overhead corridor is large and covers a large area.
  • the tower of the large-scale wind turbine is very high, and the amount of the 3-phase AC cable in the tower is large, which causes a large tower structure load, and the direct cable cost is high.
  • the capacitive effect caused by seawater will cause difficulty in power transmission of the AC system, resulting in high power transmission cost.
  • a high voltage direct current generator comprising: an alternating current multi-winding generator comprising N three-phase windings, wherein N is an integer greater than 1; 3N single-phase windings a control circuit for rectifying an alternating current outputted by each of the single-phase windings of the alternating current multi-winding generator, wherein each single-phase winding control circuit includes: a corresponding one for the alternating current multi-winding generator The single-phase winding receives the alternating current input end of the alternating current, and the direct current output end for outputting the direct current generated by rectifying the received alternating current, wherein the direct current output ends of the single-phase winding control circuits are sequentially connected in series, thereby forming a high-voltage DC output terminal, the high-voltage DC output terminal outputs a high-voltage direct current obtained by superimposing a DC potential of a DC output terminal of each single-phase winding control circuit; and a generator output controller for
  • a wind power generator set comprising a high voltage direct current generator as described above.
  • a wind farm comprising: at least one wind turbine set as described above; and a centralized internet inverter for receiving a high voltage direct current output by the wind power generator, And converting the high voltage direct current into a high voltage alternating current to access the public power grid.
  • FIG. 1 is a diagram showing the structure of a high voltage direct current generator according to an embodiment of the present invention
  • FIG. 2 is a diagram showing the structure of a single-phase winding control circuit of a high-voltage direct current generator according to an embodiment of the present invention
  • FIG. 3 is a schematic view showing a wind farm according to an embodiment of the present invention.
  • first, second, third, etc. may be used to describe different elements, components, regions, layers and/or portions, these elements, components, regions, layers and/or portions are not Should be limited by these terms. These terms are only used to distinguish one element, component, region, layer, Thus, a first element, component, region, layer, or section, which is discussed below, may be referred to as a second element, component, region, layer or section.
  • the term "and/or" as used herein includes any and all combinations of one or more of the associated listed.
  • FIG. 1 is a diagram showing the structure of a high voltage direct current generator according to an embodiment of the present invention.
  • the high voltage direct current generator includes an alternating current multi-winding generator 1, a plurality of single phase winding control (SM) circuits 2, and a generator output controller 3.
  • the AC multi-winding generator 1, the plurality of SM circuits 2, and the generator output controller 3 are connected to each other by a local bus in a high-speed, high-reliability anti-jamming motor.
  • the local bus has a high speed (>100 MBPS) high reliability feature.
  • the present invention is not limited thereto, and the AC multi-winding generator 1, the plurality of single-phase winding control (SM) circuits 2, and the generator output controller 3 may be connected through various buses.
  • the AC multi-winding generator 1 includes N three-phase windings (R1a, R1b, R1c, ..., RNab, RNb, RNc) whose outputs are 120 degrees apart.
  • N may be an integer greater than one.
  • the winding insulation of each winding increases in steps and the capacity of each winding can be unequal.
  • the AC multi-winding generator 1 may further include a tachometer winding (for example, a three-phase or two-phase tachometer winding) for measuring position information of the AC multi-winding generator 1, that is, the AC multi-winding generator 1 Intersection of each single-phase winding Angle information of the current flow.
  • the AC multi-winding generator 1 may adopt an outer rotor design or an inner rotor design, and the present invention does not impose any limitation thereon.
  • the plurality of SM circuits 2 rectify the alternating current output from the respective single-phase windings of the AC multi-winding generator 1.
  • the number of the plurality of SM circuits 2 may be 3N. That is, each SM circuit 2 corresponds to one single-phase winding of the AC multi-winding generator 1.
  • Each SM circuit 2 may include an AC input for receiving an alternating current from a respective one of the single-phase windings of the alternating current multi-winding generator, and a direct current output for outputting a direct current generated by rectifying the received alternating current .
  • the plurality of SM circuits 2 can rectify the alternating currents outputted by the plurality of single-phase windings into a plurality of direct currents having the same level as each other, and can also rectify the alternating currents outputted by the plurality of single-phase windings into a plurality of direct currents having different levels from each other.
  • the DC output terminals of the respective SM circuits 2 are connected in series to each other to constitute a high-voltage DC output terminal of the high-voltage DC current U DC obtained by superimposing the DC potential of the high-voltage DC output terminal generated by each of the single-phase winding control circuits.
  • the generator output controller 3 is for controlling each of the SM circuits 2 to perform a rectifying operation. Therefore, under the control of the generator output controller 3, the plurality of SM circuits 2 can collectively output a constant high voltage direct current. That is to say, the capacity of each winding can be custom designed, and the plurality of SM circuits 2 can control the magnitude of the direct current obtained by rectifying the alternating current of the corresponding single-phase winding, thereby collectively outputting a constant high-voltage direct current.
  • the generator output controller 3 can receive angle information of the alternating current of each single phase winding from the speed measuring winding.
  • the angle information of the alternating currents of the respective A-phase windings may be identical to each other, and the angular information of the alternating currents of the respective B-phase windings may be identical to each other, and the angular information of the alternating currents of the respective C-phase windings may be identical to each other.
  • the generator output controller 3 can also receive generator torque information from the generator main control system, and use the torque information to calculate amplitude information of the alternating current of each single-phase winding.
  • the generator output controller 3 may be based on a high-voltage DC generator design specification or based on a design specification of a wind farm including a wind turbine composed of a high-voltage DC generator, according to angle information and amplitude information of an alternating current of each single-phase winding.
  • a control signal for controlling the rectification operation of each of the SM circuits 2 is generated.
  • the generator output controller 3 can calculate the amplitude information of the alternating current of each single-phase winding using various methods, and use various methods to generate a control signal for controlling the rectification operation of each SM circuit 2, here Let me repeat.
  • the generator output controller 3 can control the respective SM circuits 2 to rectify the alternating currents of the respective single-phase windings into a plurality of direct currents having the same level as each other, and can also control the respective SMs.
  • the circuit 2 rectifies the alternating current of the corresponding single-phase winding into a plurality of direct currents having different levels from each other flow.
  • the generator output controller 3 can control the respective SM circuits 2 to adjust the level of the direct current obtained by rectifying the alternating current of the respective single-phase windings.
  • the generator output controller 3 may also calculate generator torque information based on a pre-designed generator torque calculation algorithm.
  • the calculation algorithm can be designed according to a specific situation by using various methods for calculating the generator torque of the prior art by those skilled in the art, and details are not described herein again.
  • each of the SM circuits 2 can spatially interact with the corresponding single-phase windings. Arranged close to each other. That is to say, each SM circuit 2 can be at a very close distance (for example, a "0" distance) in spatial distance from the corresponding single-phase winding. Usually, this distance is considered not to exceed 10 m.
  • the invention is not limited thereto, and the distance (for example, 10 m) is limited only by the position of the actual spatial arrangement of the generators (ie, the individual single-phase windings) and the power electronic devices (ie, the respective SM currents 2).
  • FIG. 2 is a diagram showing the structure of a single-phase winding control circuit of a high voltage direct current generator according to an embodiment of the present invention.
  • the SM circuit 2 may include an H-bridge rectifier circuit 21, a capacitor 22, and a diode 23.
  • the H-bridge rectifier circuit 21 may include four power electronic switching elements (S1 to S4), each of which may include a controllable power semiconductor device (eg, IGBT, MOSFET, etc.) and one and the controllable power semiconductor device Anti-parallel protection diode.
  • the H-bridge rectifier circuit 21 can receive an AC current from a corresponding one-phase winding of the AC multi-winding generator through the AC input terminal of the SM circuit 2, rectify the received AC current to generate a DC current, and pass the DC of the SM circuit 2. The DC current generated by the output of the output.
  • the rectification operating principle of the H-bridge rectifier circuit 21 is well known to those skilled in the art, and a detailed description thereof is omitted herein.
  • the capacitor 22 is connected in parallel with the H-bridge rectifier circuit at the DC output for power buffering and voltage support of the output of the H-bridge rectifier circuit 21.
  • the diode 23 is used to ensure that the series configuration of the DC output terminals of the respective SM circuits 2 can still operate normally in the case of a single-phase winding failure corresponding to the SM circuit 2 or other components in the SM circuit 2.
  • the diode 23 is anti-parallel to each of the power electronic switching elements of the H-bridge rectifier circuit 21, so that when the single-phase winding corresponding to the SM circuit 2 fails or other components in the SM circuit 2 fail, the diode 23 is turned on.
  • the series structure between the SM circuit 2 and the other plurality of SM circuits 2 still works normally.
  • only the other plurality of SM circuits 2 need to appropriately adjust the rectifying operation of the H-bridge rectifying circuit 21, and the constant high-voltage DC can still be output through the other plurality of SM circuits 2.
  • Current In other words, by providing the diode 23 in each of the SM circuits 2, the high voltage direct current generator can be provided with redundant output capability.
  • the SM circuit 2 can also include a drive circuit 24.
  • the driving circuit 24 can receive the control signal generated by the generator output controller 3, and drive each of the power electronic switching elements in the H-bridge rectifier circuit 21 to be turned on and/or off according to the control signal, to correspond to the corresponding single phase.
  • the AC current received by the winding is rectified.
  • the generator output controller 3 can generate a control signal suitable for the SM circuit 2 corresponding to the specific single-phase winding based on the angle information and the amplitude information of the alternating current of the specific single-phase winding.
  • the control signal may include information indicating the time at which each of the power electronic switching elements in the H-bridge rectifier circuit 21 is turned "on" and/or off.
  • the drive circuit 24 can control the timing and duration of the on and/or off of the respective power electronic switching elements in the H-bridge rectifier circuit 21 according to the control signal, thereby adjusting the level of the direct current generated by the H-bridge rectifier circuit 21. .
  • the drive circuit 24 includes an interface unit 241, a control unit 242, a drive unit 243, a voltage/current sampling unit 244, and a power supply unit 255.
  • the interface unit 241 can receive a control signal from the generator output controller 3.
  • the control unit 242 can generate a drive signal that drives the respective power electronic switching elements in the H-bridge rectifier circuit 21 to be turned on and/or off according to the control signal received by the interface unit 241.
  • the driving unit 243 may apply a driving signal generated by the control unit 242 to each of the power electronic switching elements in the H-bridge rectifying circuit 21 to drive the respective power electronic switching elements to be turned on and/or off.
  • the voltage/current sampling unit 244 can sample the voltage/current of the H-bridge rectifier circuit 21 and feed back the sampling result to the control unit 242 to adjust the drive signal. In other words, feedback control of the respective power electronic switching elements in the H-bridge rectifier circuit 21 can be achieved by voltage/current sampling.
  • power supply unit 255 is used to power drive circuit 24. That is, the power supply unit 255 can supply power to the interface unit 241, the control unit 242, the drive unit 243, and the voltage/current sampling unit 244.
  • the generator since the generator is integrated with the power electronic device (ie, the AC multi-winding generator 1 and the plurality of SM circuits 2), the conventional low-voltage, variable-voltage, variable-frequency output permanent magnet generator can be used.
  • a generator set that is integrated into a fixed voltage DC output.
  • the genset is used in a wind turbine, a large amount of power transmission costs (including cables, transformers, etc.) can be saved.
  • the generator set is used for the wind power generator, the natural cooling of the wind can be adopted, thereby simplifying the system cooling structure and improving the system reliability.
  • the design of the generator output controller enables the integrated operation of the generator set and monitoring, thereby reducing the maintenance cost of the generator set.
  • FIG. 3 is a schematic view showing a wind farm according to an embodiment of the present invention.
  • wind farm 30 may include a plurality of wind turbines 310 constructed of high voltage direct current generators as described above.
  • the wind turbine 310 can output 20 KV of DC power, the output voltage of which does not change with the change of the speed of the generator, and the output current can be determined by the input power of the generator.
  • wind turbine 300 can include a high voltage direct current generator as described above.
  • the wind turbine set 300 may further include a DC transmission cable connected to the high voltage DC generator, the DC transmission cable being disposed inside the tower of the high voltage DC generator, and adopting a high voltage DC two-wire power transmission mode.
  • control system of the wind turbine 310 may draw power directly from the high voltage DC grid inside the wind farm 30, or may be powered by the auxiliary power winding provided by the wind turbine 310.
  • low-voltage power can be obtained by the field-level transformer of the wind farm 30, and then auxiliary power is supplied to the control system of the wind turbine 310 (for example, the generator output controller of the high-voltage direct-current generator) through a specially-configured auxiliary power supply network.
  • the manner in which the control system of the wind turbine 310 (for example, the generator output controller of the high voltage direct current generator) acquires power is not the focus of the present invention, and a detailed description thereof is omitted here.
  • the wind farm 30 adopts a flexible high-voltage direct current transmission mode instead of the power transmission mode in the conventional AC wind farm.
  • the wind farm also includes a centralized internet inverter 320.
  • the centralized internet inverter 320 can receive the high voltage direct current output by the plurality of wind power generator sets 310 and convert the high voltage direct current into a high voltage alternating current.
  • the centralized internet inverter 320 may be a centralized power electronic conversion device based on MMC (Modular Multilevel Converter) technology.
  • MMC Modular Multilevel Converter
  • wind farm 30 may also include a public network transformer 330 and a wind farm control device 340.
  • the public network transformer 330 is configured to connect the high voltage alternating current outputted by the centralized internet inverter 320 to the public power grid
  • the wind farm control device 340 is configured to stabilize the high voltage direct current output by the plurality of wind power generator sets 310 and to the plurality of wind power generating units. 310 performs power scheduling control.
  • the wind farm control device 340 can control the plurality of wind turbines 310 by various control algorithms, and details are not described herein again.
  • the wind power generator in the wind farm is composed of a high voltage direct current generator, the cost of transmission in the tower of the wind turbine can be reduced.
  • the power transmission in the tower uses cables, and the biggest factor affecting the cost of the cable is the current transmitted by the cable. The higher the current, the higher the cost and weight of the cable, and the same after increasing the output voltage of the wind turbine.
  • the current output from the wind turbine is reduced at power, thereby reducing the cost of transmission within the tower of the wind turbine.
  • the wind turbine in the wind farm is composed of a high-voltage DC generator
  • the wind turbine can be inertially integrated into the DC link of the system, and the centralized inverter can avoid the inertia of the wind turbine directly connected to the public grid.
  • the stability of the wind farm since the wind turbine in the wind farm is composed of a high-voltage DC generator and the wind farm uses DC transmission, the cable parasitic capacitance caused by seawater will increase the DC capacitance for DC, which brings positive to offset the inertia of the system. Impact.
  • the wind turbine in the wind farm is composed of a high-voltage DC generator, the two-wire transmission can be adopted in the wind farm.
  • the cable transmission corridor is easier to design with a lower footprint because one cable is used less and there is only one potential difference. Thereby reducing the land use area of power transmission, resulting in better economic and social benefits.

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

Abstract

高压直流发电机、风力发电机组和风电场。高压直流发电机包括：交流多绕组发电机（1），包括N个三相绕组；3N个单相绕组控制电路（2），每个单相绕组控制电路（2）包括：用于接收交流电流的交流输入端，以及用于输出直流电流的直流输出端，各个单相绕组控制电路的直流输出端依次串联，从而构成高压直流输出端；发电机输出控制器（3），用于控制各个单相绕组控制电路（2）进行整流操作。

Description

高压直流发电机、风力发电机组和风电场 技术领域
本发明涉及发电机领域，更具体地讲，涉及一种能够输出恒定的高压直流电流的高压直流发电机、包括所述高压直流发电机的风力发电机组和风电场。
背景技术
基于永磁发电机的直驱型发电机组通常采用大体积、大功率、低转速的发电机。例如，在风力发电系统中，发电机输出电力通常需要通过塔内传输至塔底电力电子换流装置，然后经工频变压器接入风电场区域公共交流电网。这种发电机的输出通常具备以下特征：低电压变电压、3相交流、变频率等。
然而，这种发电机在具体应用中存在许多不足。首先，发电机不能直接并入交流电网或直流电网，而需要加装电力电子换流装置才能并入交流电网或直流电网。第二，发电机工作电压低，因此导致风力发电机组塔内电力传输费用高昂(包括高昂的电缆成本以及由大量电缆的重量而导致的塔架及塔架内电缆安装成本)。第三、低电压下的电力电子换流装置会导致高昂的散热成本。
通常，具有多个这种发电机的风电场将会采用交流并网方案，即，多个发电机通过变流设备接入交流电网。交流并网方案是目前世界上比较成熟的电力并网方案，然而，其在风力发电机场上的应用仍然存在一些不足。首先，风力发电机组的惯性各自表达输入到交流功率总线，在大规模多点并入时，这些惯性会引起并网端点复杂低频功率耦合，容易造成电网低频问题。第二，风电场内采用3线传输，架空走廊较大，占地面积大。第三、大型风力发电机组的塔架很高，塔内3相交流电缆的用量很大，造成很大的塔架结构负担，并且直接电缆成本很高。第四、在例如大海的特定地域内进行交流传输时，由于海水造成的电容效应，将导致交流系统功率传输困难，从而导致很高的电力传输成本。
发明内容
根据本发明的一方面，提供一种高压直流发电机，所述高压直流发电机包括：交流多绕组发电机，包括N个三相绕组，其中，N为大于1的整数；3N个单相绕组控制电路，用于对所述交流多绕组发电机的各个单相绕组输出的交流电流进行整流，其中，每个单相绕组控制电路包括：用于从所述交流多绕组发电机的相应的一个单相绕组接收交流电流的交流输入端，以及，用于输出对接收的交流电流进行整流而产生的直流电流的直流输出端，其中，各个单相绕组控制电路的直流输出端依次串联，从而构成高压直流输出端，所述高压直流输出端输出通过叠加各个单相绕组控制电路的直流输出端的直流电势而获得的高压直流电流；发电机输出控制器，用于控制各个单相绕组控制电路进行整流操作。
根据本发明的另一方面，提供一种风力发电机组，所述风力发电机组包括如上所述的高压直流发电机。
根据本发明的另一方面，提供一种风电场，所述风电场包括：至少一个如上所述风力发电机组；以及集中上网逆变器，用于接收所述风力发电机组输出的高压直流电流，并将所述高压直流电流转换为高压交流电流以接入公共电网。
附图说明
通过下面结合附图对实施例进行的描述，本发明的这些和/或其他方面和优点将会变得清楚和更易于理解，在附图中：
图1是示出根据本发明实施例的高压直流发电机的结构的示图；
图2是示出根据本发明实施例的高压直流发电机的单相绕组控制电路的结构的示图；
图3是示出根据本发明实施例的风电场的示意性示图。
具体实施方式
在下文中参照附图更充分地描述本发明，在附图中示出了本发明的示例性实施例。然而，本发明可以以许多不同的形式来实施，且不应该解释为局限于在这里所提出的实施例。相反，提供这些实施例使得本公开将是彻底和完全的，并将本发明的范围充分地传达给本领域技术人员。在附图中，相同 的标号始终表示相同的元件。
应该理解的是，尽管在这里可使用术语第一、第二、第三等来描述不同的元件、组件、区域、层和/或部分，但是这些元件、组件、区域、层和/或部分不应该受这些术语的限制。这些术语仅是用来将一个元件、组件、区域、层或部分与另一个元件、组件、区域、层或部分区分开来。因此，在不脱离本发明的教导的情况下，下面讨论的第一元件、组件、区域、层或部分可被称作第二元件、组件、区域、层或部分。如在这里使用的，术语“和/或”包括一个或多个相关所列项的任意组合和所有组合。
这里使用的术语仅为了描述特定实施例的目的，而不意图限制本发明。如这里所使用的，除非上下文另外明确指出，否则单数形式也意图包括复数形式。还应理解的是，当在本说明书中使用术语“包含”和/或“包括”时，说明存在所述特征、整体、步骤、操作、元件和/或组件，但不排除存在或附加一个或多个其它特征、整体、步骤、操作、元件、组件和/或它们的组。
除非另有定义，否则这里使用的所有术语(包括技术术语和科学术语)具有与本发明所属领域的普通技术人员所通常理解的意思相同的意思。还将理解的是，除非这里明确定义，否则术语(诸如在通用字典中定义的术语)应该被解释为具有与相关领域的环境中它们的意思一致的意思，而将不以理想的或者过于正式的含义来解释它们。
在下文中，将参照附图详细地解释本发明。
图1是示出根据本发明实施例的高压直流发电机的结构的示图。
参照图1，所述高压直流发电机包括交流多绕组发电机1、多个单相绕组控制(SM)电路2和发电机输出控制器3。根据本发明实施例，交流多绕组发电机1、多个SM电路2和发电机输出控制器3通过高速高可靠抗干扰电机内局部总线彼此连接。这里，所述局部总线具备高速(>100MBPS)高可靠性特征。然而，本发明不限于此，可通过各种总线连接交流多绕组发电机1、多个单相绕组控制(SM)电路2和发电机输出控制器3。
交流多绕组发电机1包括N个输出互差120度的三相绕组(R1a、R1b、R1c、……RNa、RNb、RNc)。这里，N可以为大于1的整数。各个绕组的绕组绝缘成梯次增加，并且每套绕组容量可以不相等。可选择地，交流多绕组发电机1还可包括一个测速绕组(例如，三相或二相测速绕组)，用于测量交流多绕组发电机1的位置信息，即，交流多绕组发电机1的各个单相绕组的交 流电流的角度信息。此外，交流多绕组发电机1可采用外转子设计或内转子设计，本发明对此不进行任何限制。
多个SM电路2对交流多绕组发电机1的各个单相绕组输出的交流电流进行整流。多个SM电路2的数量可以是3N个。也就是说，每个SM电路2对应于交流多绕组发电机1的一个单相绕组。每个SM电路2可包括用于从交流多绕组发电机的相应的一个单相绕组接收交流电流的交流输入端，以及用于输出对接收的交流电流进行整流而产生的直流电流的直流输出端。多个SM电路2可将多个单相绕组输出的交流电流整流为电平彼此相同的多个直流电流，也可将多个单相绕组输出的交流电流整流为电平彼此不同的多个直流电流。各个SM电路2的直流输出端彼此串联，从而构成输出通过叠加各个单相绕组控制电路产生的高压直流输出端的直流电势而获得的高压直流电流UDC的高压直流输出端。
发电机输出控制器3用于控制各个SM电路2进行整流操作。因此，在发电机输出控制器3的控制之下，多个SM电路2可共同地输出恒定的高压直流电流。也就是说，每个绕组的容量可以定制设计，多个SM电路2可控制通过对相应的单相绕组的交流电流整流而得到的直流电流的幅值，从而共同地输出恒定的高压直流电流。
具体地讲，发电机输出控制器3可从测速绕组接收各个单相绕组的交流电流的角度信息。这里，各个A相绕组的交流电流的角度信息可以彼此相同，各个B相绕组的交流电流的角度信息可以彼此相同，各个C相绕组的交流电流的角度信息可以彼此相同。同时，发电机输出控制器3还可从发电机主控系统接收发电机扭矩信息，利用所述扭矩信息计算各个单相绕组的交流电流的幅值信息。发电机输出控制器3可基于高压直流发电机设计规格，或者基于包括由高压直流发电机构成的风力发电机组的风电场的设计规格，根据各个单相绕组的交流电流的角度信息和幅值信息产生用于控制各个SM电路2进行整流操作的控制信号。这里，发电机输出控制器3可使用各种方法来计算各个单相绕组的交流电流的幅值信息，并且使用各种方法来产生用于控制各个SM电路2进行整流操作的控制信号，这里不再赘述。通过将产生的控制信号施加到各个SM电路2，发电机输出控制器3可以控制各个SM电路2将相应单相绕组的交流电流整流为电平彼此相同的多个直流电流，也可以控制各个SM电路2将相应单相绕组的交流电流整流为电平彼此不同的多个直流电 流。同时，通过将不同的控制信号施加到各个SM电路2，发电机输出控制器3可以控制各个SM电路2调整通过对相应单相绕组的交流电流进行整流获得的直流电流的电平。
可选择地，发电机输出控制器3还可基于预先设计的发电机扭矩计算算法计算发电机扭矩信息。所述计算算法可以由本领域技术人员使用现有技术的计算发电机扭矩的各种方法根据具体情况进行设计，这里不再赘述。
根据本发明实施例，由于SM电路2采用模块化设计并且在所述高压直流发电机中使用高速高可靠抗干扰电机内局部总线，因此各个SM电路2可以与相应的单相绕组在空间上彼此彼此接近地布置。也就是说，各个SM电路2与相应的单相绕组在空间距离上可处于极近的距离(例如，“0”距离)。通常，该距离被认为不会不超过10m。然而，本发明不限于此，该距离(例如，10m)仅由发电机(即，各个单相绕组)与电力电子装置(即，各个SM电流2)的实际空间布置的位置来限制。
图2是示出根据本发明实施例的高压直流发电机的单相绕组控制电路的结构的示图。
参照图2，SM电路2可包括H桥整流电路21、电容器22和二极管23。H桥整流电路21可包括四个电力电子开关元件(S1至S4)，每个电力电子开关元件可包括一个可控功率半导体器件(例如，IGBT、MOSFET等)和一个与该可控功率半导体器件反并联的保护二极管。H桥整流电路21可通过SM电路2的交流输入端从交流多绕组发电机的相应的一个单相绕组接收交流电流，对接收的交流电流进行整流以产生直流电流，并通过SM电路2的直流输出端输出产生的直流电流。H桥整流电路21的整流工作原理为本领域技术人员所公知，这里省略其具体描述。电容器22在直流输出端与H桥整流电路并联连接，用于对H桥整流电路21的输出进行功率缓冲和电压支撑。二极管23用于确保在与SM电路2相应的单相绕组故障或者SM电路2中的其他元件故障的情况下，各个SM电路2的直流输出端的串联结构仍能正常工作。根据本发明实施例，二极管23与H桥整流电路21的各个电力电子开关元件反并联，因此当与SM电路2相应的单相绕组故障或者SM电路2中的其他元件故障时，二极管23导通，从而确保该SM电路2与其他多个SM电路2之间的串联结构仍能正常工作。此时，只需所述其他多个SM电路2适当地调整H桥整流电路21的整流操作，仍然可以通过所述其他多个SM电路2输出恒定的高压直流 电流。换言之，通过在各个SM电路2中设置二极管23，可使所述高压直流发电机具备冗余输出能力。
继续参照图2，SM电路2还可包括驱动电路24。驱动电路24可接收发电机输出控制器3产生的控制信号，并根据所述控制信号驱动H桥整流电路21中的各个电力电子开关元件接通和/或断开，以对从相应的单相绕组接收的交流电流进行整流。如上所述，发电机输出控制器3可根据特定单相绕组的交流电流的角度信息和幅值信息产生适用于与所述特定单相绕组相应的SM电路2的控制信号。例如，控制信号可包含指示H桥整流电路21中的各个电力电子开关元件接通和/或断开的时间的信息。驱动电路24可根据所述控制信号控制H桥整流电路21中的各个电力电子开关元件的接通和/或断开的时序和持续时间，从而调整H桥整流电路21产生的直流电流的电平。
继续参照图2，驱动电路24包括接口单元241、控制单元242、驱动单元243、电压/电流采样单元244和电源单元255。具体地讲，接口单元241可从发电机输出控制器3接收控制信号。控制单元242可根据接口单元241接收的控制信号产生驱动H桥整流电路21中的各个电力电子开关元件接通和/或断开的驱动信号。驱动单元243可将控制单元242产生的驱动信号施加到H桥整流电路21中的各个电力电子开关元件，以驱动所述各个电力电子开关元件接通和/或断开。电压/电流采样单元244可对H桥整流电路21的电压/电流进行采样，并将采样结果反馈到控制单元242，以调整驱动信号。换言之，通过电压/电流采样，可实现对H桥整流电路21中的各个电力电子开关元件的反馈控制。此外，电源单元255用于为驱动电路24供电。即，电源单元255可以为接口单元241、控制单元242、驱动单元243以及电压/电流采样单元244供电。
根据本发明实施例，由于发电机与电力电子装置(即，交流多绕组发电机1与多个SM电路2)整合设计，因此可以将传统的低压、变压、变频率输出的永磁发电机整合为固定电压直流输出的发电机组。当所述发电机组用于风力发电机组时，能够节省大量的电力传输成本(包括电缆、变压器等)。此外，由于发电机与电力电子装置整合设计，因此当所述发电机组用于风力发电机组时，可以采用风力自然冷却，从而简化了系统冷却结构，提高了系统可靠性。此外，发电机输出控制器的设计使得发电机组的工作及监控实现一体化设计，从而减低了发电机组的维护成本。
图3是示出根据本发明实施例的风电场的示意性示图。
参照图3，风电场30可包括多个由如上所述的高压直流发电机构成的风力发电机组310。例如，风力发电机组310可输出20KV的直流电力，其输出电压不随发电机的转速变化而变化，其输出电流可由发电机的输入功率决定。具体地讲，风力发电机组300可包括如上所述的高压直流发电机。此外，风力发电机组300还可包括与高压直流发电机连接的直流输送电缆，所述直流输送电缆设置在高压直流发电机的塔筒内部，且采用高压直流二线制功率传输模式。此外，风力发电机组310的控制系统(例如，高压直流发电机的发电机输出控制器)可以从风电场30内部的高压直流电网直接取电，或者通过风力发电机组310提供的辅助动力绕组取电。此外，还可通过风电场30的场级变压器取得低压电力，然后通过专门设置的辅助动力电源网络向风力发电机组310的控制系统(例如，高压直流发电机的发电机输出控制器)提供辅助电力。风力发电机组310的控制系统(例如，高压直流发电机的发电机输出控制器)获取电力的方式不是本发明所关注的焦点，这里省略其详细描述。
根据本发明的实施例，风电场30采用柔性高压直流传输方式，替代传统的交流风电场内的电力传输方式。为此，所述风电场还包括集中上网逆变器320。集中上网逆变器320可接收多个风力发电机组310输出的高压直流电流，并将所述高压直流电流转换为高压交流电流。这里，集中上网逆变器320可以是基于MMC(模块化多电平换流器)技术的集中电力电子变换装置。通过采用柔性高压直流传输方式，当从公共电网看风电场30时，风电场30可以等效为一台由电力电子设备构成的大型发电机组。
继续参照图3，风电场30还可包括公网变压器330和风电场控制设备340。公网变压器330用于将集中上网逆变器320输出的高压交流电流接入公共电网，风电场控制设备340用于稳定多个风力发电机组310输出的高压直流电流，并对多个风力发电机组310进行功率调度控制。根据本发明实施例，风电场控制设备340可采用各种控制算法对多个风力发电机组310进行控制，这里不再赘述。
通过构建如上所述的根据本发明实施例的风电场，由于风电场中的风力发电机组由高压直流发电机构成，因此可降低风力发电机组塔架内传输的成本。塔架内的电力传输使用电缆，而影响电缆成本的最大因素是电缆传输的电流，电流越大电缆成本及重量越高，提升风力发电机组输出电压后，相同 功率下风力发电机组输出的电流降低，从而降低了风力发电机组塔架内传输的成本。此外，由于风电场中的风力发电机组由高压直流发电机构成，因此可将风力发电机组惯性汇入系统直流环节，而采用集中逆变的方式可避免风力发电机组惯性直接接入公共电网，从而提高风电场的稳定性。此外，由于风电场中的风力发电机组由高压直流发电机构成，风电场内采用直流传输，因此海水造成的电缆寄生电容对直流而言将增大直流电容，这为抵消系统惯性带来了积极的影响。此外，由于风电场中的风力发电机组由高压直流发电机构成，因此风电场内可采用二线制传输。这与三线制的交流传输(3根电缆两种电位差)相比，由于少用1根电缆且只有一种电位差，因此使得电缆的传输走廊较为容易地进行占地面积较低的设计，从而减少了电力传输的大地使用面积，带来更好的经济及社会效益。
虽然已经显示和描述了一些实施例，但是本领域技术人员应该理解，在不脱离本发明的原理和精神的情况下，可以对这些实施例进行修改，本发明的范围由权利要求及其等同物限定。

Claims (10)

  1. 一种高压直流发电机，其特征在于，所述高压直流发电机包括：
    交流多绕组发电机，包括N个三相绕组，其中，N为大于1的整数；
    3N个单相绕组控制电路，用于对所述交流多绕组发电机的各个单相绕组输出的交流电流进行整流，其中，每个单相绕组控制电路包括：
    用于从所述交流多绕组发电机的相应的一个单相绕组接收交流电流的交流输入端，以及，
    用于输出对接收的交流电流进行整流而产生的直流电流的直流输出端，其中，各个单相绕组控制电路的直流输出端依次串联，从而构成高压直流输出端，所述高压直流输出端输出通过叠加各个单相绕组控制电路的直流输出端的直流电势而获得的高压直流电流；
    发电机输出控制器，用于控制各个单相绕组控制电路进行整流操作。
  2. 如权利要求1所述的高压直流发电机，其特征在于，所述交流多绕组发电机还包括测速绕组，所述测速绕组用于测量各个单相绕组的交流电流的角度信息；
    所述发电机输出控制器与所述测速绕组连接，用于根据测量得到的所述各个单相绕组的交流电流的角度信息，控制各个单相绕组控制电路进行整流操作。
  3. 如权利要求2所述的高压直流发电机，其特征在于，所述发电机输出控制器用于从发电机外部控制系统接收发电机扭矩信息或者基于预先设计的发电机扭矩计算算法计算发电机扭矩信息，利用所述扭矩信息计算各个单相绕组的交流电流的幅值信息，并且根据各个单相绕组的交流电流的角度信息和幅值信息产生控制信号，以及根据所述控制信号控制各个单相绕组控制电路进行整流操作。
  4. 如权利要求3所述的高压直流发电机，其特征在于，每个单相绕组控制电路包括：
    H桥整流电路，通过所述交流输入端从交流多绕组发电机的相应的一个单相绕组接收交流电流，对接收的交流电流进行整流以产生直流电流，并通过所述直流输出端输出产生的直流电流；
    电容器，在所述直流输出端与所述H桥整流电路并联连接；
    二极管，在所述直流输出端与所述H桥整流电路并联连接。
  5. 如权利要求4所述的高压直流发电机，其特征在于，每个单相绕组控制电路还包括：
    驱动电路，用于接收所述发电机输出控制器产生的控制信号，并根据所述控制信号驱动所述H桥整流电路中的各个电力电子开关元件接通和/或断开，以对所述交流电流进行整流。
  6. 如权利要求5所述的高压直流发电机，其特征在于，所述驱动电路包括：
    接口单元，用于从所述发电机输出控制器接收所述控制信号；
    控制单元，用于根据所述控制信号产生驱动所述H桥整流电路中的各个电力电子开关元件接通和/或断开的驱动信号；
    驱动单元，用于将所述驱动信号施加到所述H桥整流电路中的各个电力电子开关元件，以驱动所述各个电力电子开关元件接通和/或断开；
    电压/电流采样单元，用于对所述H桥整流电路的电压/电流进行采样，并将采样结果反馈到所述控制单元，以调整所述驱动信号；
    电源单元，用于为所述驱动电路供电。
  7. 一种风力发电机组，其特征在于，所述风力发电机组包括如权利要求1-6中任一项所述的高压直流发电机。
  8. 如权利要求7所述的风力发电机组，其特征在于，所述风力发电机组还包括与所述高压直流发电机连接的直流输送电缆，所述直流输送电缆设置在所述高压直流发电机的塔筒内部，且采用高压直流二线制功率传输模式。
  9. 一种风电场，其特征在于，所述风电场包括：
    至少一个如权利要求7或8所述的风力发电机组；以及
    集中上网逆变器，用于接收所述风力发电机组输出的高压直流电流，并将所述高压直流电流转换为高压交流电流以接入公共电网。
  10. 如权利要求9所述的风电场，其特征在于，所述风电场还包括：
    公网变压器，连接所述集中上网逆变器与所述公共电网；或者/并且，
    风电场控制设备，用于稳定所述风力发电机组输出的高压直流电流，并对所述至少一个风力发电机组进行功率调度控制。
PCT/CN2017/115420 2017-05-31 2017-12-11 高压直流发电机、风力发电机组和风电场 WO2018218924A1 (zh)

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