WO2022041365A1 - 一种适用于电压源型换流器的限功率方法 - Google Patents

一种适用于电压源型换流器的限功率方法 Download PDF

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WO2022041365A1
WO2022041365A1 PCT/CN2020/116989 CN2020116989W WO2022041365A1 WO 2022041365 A1 WO2022041365 A1 WO 2022041365A1 CN 2020116989 W CN2020116989 W CN 2020116989W WO 2022041365 A1 WO2022041365 A1 WO 2022041365A1
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converter station
power
voltage
converter
control
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PCT/CN2020/116989
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English (en)
French (fr)
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李周
魏子昂
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东南大学溧阳研究院
东南大学
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    • 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
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • 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
    • 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
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
    • 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
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Definitions

  • the invention belongs to the technical field of power systems, and relates to a power limiting method suitable for a voltage source converter.
  • HVDC transmission based on voltage source converters that is, flexible DC transmission
  • Flexible DC transmission is widely used in new energy collection scenarios such as wind power collection because of its advantages of realizing active and reactive power decoupling control, supplying power to passive networks, and providing reactive power support.
  • the voltage source converter adopts the original Control strategies (such as amplitude-phase control, amplitude-frequency control, active and reactive power coupling control, or constant AC voltage control) cannot effectively constrain the line power when stabilizing the system AC voltage, and the overall system stability is poor.
  • the present invention sets a power limiting strategy based on the capacity of the converter station, and proposes a power limiting method suitable for voltage source converters.
  • Transmission power When the transmission power exceeds the capacity of the converter station, the converter station is switched from the original control strategy to the limited power control mode to limit the transmission power of the converter station to ensure that the system power does not exceed the limit.
  • the transmission power of the converter station returns to normal, the converter station switches back to the original control strategy.
  • the present invention proposes a power limiting method suitable for a voltage source converter, comprising the following steps:
  • the converter station When the transmission power of the converter station exceeds the upper limit of the transmission power of the converter station, the converter station is switched from the original control strategy to the limited power control mode to limit the transmission power of the converter station;
  • the process of switching the converter station from the original control strategy to the power-limited control mode is: according to the upper limit of the transmission capacity of the converter station, calculate the phase difference between the Pcc point and the AC outlet side voltage of the converter station when the transmission capacity is limited. Angle difference, and then adjust the phase angle of the AC outlet side voltage of the converter station to ensure that the two phase angles change synchronously, thereby limiting the transmission power of the converter station.
  • the process of switching the converter station from the original control strategy to the power-limited control mode specifically includes the following steps:
  • the power limit is realized by giving the output value of the inner loop of the constant AC voltage controller, including:
  • the original control strategy is amplitude-phase control, amplitude-frequency control or active and reactive power coupling control
  • the amplitude and phase angle of the AC voltage of the converter station are given at the same time to achieve power limiting, which specifically includes the following steps:
  • M, f and ⁇ sa are the voltage amplitude, frequency and phase angle commands at the Pcc point
  • ⁇ ca is the AC side outlet voltage phase angle (A phase) command
  • f s is the AC system frequency
  • the AC side outlet voltage is:
  • U sd and U sq are the dq-axis components of the AC voltage at the common connection point
  • U cd and U cq are the dq-axis components of the AC side outlet voltage of the converter station
  • sd and i sq are The dq-axis components of the AC side current of the converter station
  • k p and k i are the proportional and integral coefficients of the proportional integrator
  • R c and X c are the equivalent resistance and commutation reactance of the converter station;
  • the power injected into the AC side outlet of the converter from the common connection point is:
  • P s and Q s are the active power and reactive power injected at the common connection point;
  • U s is the AC voltage amplitude at the common connection point, and
  • U c is the AC voltage amplitude at the outlet of the AC side of the converter station;
  • ⁇ is the phase angle difference between U s and U c .
  • the original control strategy controls the amplitude, frequency and phase of the AC voltage at the common connection point of the connected AC system or at the AC outlet of the inverter through the inverter.
  • the original control strategy is one of the following strategies: amplitude-phase control, amplitude-frequency control, active and reactive power coupling control, and constant AC voltage control.
  • the original control strategy is determined based on the system structure.
  • the present invention has the following advantages and beneficial effects:
  • the method of the invention calculates the phase angle difference between the Pcc point and the voltage at the AC outlet side of the converter station according to the upper limit of the transmission capacity of the converter station, and then adjusts the phase angle of the voltage at the AC outlet side of the converter station to ensure that the two phase angles change synchronously, so as to achieve Power limiting effect.
  • the method of the invention can effectively constrain the power, and solve the problem that the voltage source converter cannot constrain the power when the AC voltage is stabilized by strategies such as amplitude-phase control, amplitude-frequency control, active and reactive power coupling control and constant AC voltage control;
  • the maximum utilization of the converter capacity improves the safety and stability of the DC system.
  • FIG. 1 is a schematic diagram of a single-ended VSC system applying the method of the present invention, taking constant AC voltage control as an example.
  • FIG. 2 is a schematic structural diagram of a double-ended VSC system applying the method of the present invention.
  • Fig. 3 is a control structure diagram of a constant AC voltage, wherein (a) is a d-axis control structure diagram, and (b) is a q-axis control structure diagram.
  • Figure 4 is a structural diagram of the amplitude and phase control.
  • Figure 5 is a structural diagram of the simulation model of the flexible HVDC transmission system.
  • Fig. 6 is the simulation waveform of the transmission power of the converter station.
  • the power limiting method applicable to the voltage source converter provided by the present invention is applied to the system as shown in FIG. 1 and FIG. 2 , and includes the following steps:
  • Step 1 According to the system structure, determine the original control strategy of the system
  • Step 2 When the original control strategy of the system is amplitude-phase control (the control structure is shown in Figure 4), amplitude-frequency control, active and reactive power coupling control or constant AC voltage control, etc. (the above control strategy controls the connected AC through the inverter.
  • the amplitude, frequency and phase of the AC voltage at the system common connection point (PCC point) or at the AC outlet of the converter) in the dq rotating coordinate system, the AC side outlet voltage is:
  • U sd and U sq are the dq-axis components of the AC voltage at the common connection point
  • U cd and U cq are the dq-axis components of the AC side outlet voltage of the converter station
  • is sd and i sq are The dq-axis components of the AC side current of the converter station
  • k p and k i are the proportional and integral coefficients of the proportional integrator
  • R c and X c are the equivalent resistance and commutation reactance of the converter station.
  • the power injected into the AC side outlet of the converter from the common connection point (PCC point) is:
  • P s and Q s are the active power and reactive power injected at the common connection point (PCC point);
  • U s is the AC voltage amplitude at the common connection point, and
  • U c is the AC side exit of the converter station.
  • ⁇ is the phase angle difference between U s and U c .
  • Step 3 According to the converter capacity, when the transmission power exceeds the capacity of the converter station, the converter station is switched from the original control strategy to the power-limited control mode to limit the transmission power of the converter station to ensure that the system power does not exceed the limit.
  • the converter station Setting the upper limit of power transmission for the transmission power of the converter station and Detect the transmission power of the FM converter station, if the transmission power does not meet the Then the converter station is switched to limited power control. and is the maximum transmission power of the converter station, where Represents the maximum value of the transmission power in the rectification direction, which means that the active power is injected into the converter station by the AC system; Represents the maximum value of the transmission power in the inverter direction, that is, the active power is injected into the AC system by the converter station.
  • the method of the invention calculates the phase angle difference between the Pcc point and the voltage at the AC outlet side of the converter station according to the upper limit of the transmission capacity of the converter station, and then adjusts the phase angle of the voltage at the AC outlet side of the converter station to ensure that the two phase angles change synchronously, so as to achieve Power limiting effect. Specifically, it includes the following steps:
  • the controller output command is set as:
  • the AC side outlet voltage command is set as:
  • M, f and ⁇ sa are the voltage amplitude, frequency and phase angle (A-phase) commands at the Pcc point, and f s is the frequency of the AC system.
  • ⁇ ca is the AC side outlet voltage phase angle (A phase) command respectively.
  • Step 4 When the transmission power of the converter station returns to normal, that is, the transmission power of the converter station meets the The converter station switches back to the original control strategy, that is, the control strategy in step 2.
  • the AC system connected to the VSC adopts amplitude and phase control, and the transmission power range of the converter station is -750MW ⁇ P s ⁇ 750MW .
  • the transmission power of the VSC converter station is -450MW.
  • the load of the AC system connected to the VSC increased by 200MW, but did not reach the upper limit of the transmission capacity of the converter station
  • the load of the AC system connected to the VSC increases by 150MW, reaching the upper limit of the transmission capacity of the converter station
  • the AC system connected to the VSC removes the 200MW load.
  • the AC system connected to the VSC removes the 150MW load, and the system returns to a stable state.
  • the power reference value is 750MVA
  • the AC voltage reference value is 500kV
  • the DC voltage reference value is 500kV
  • the per unit value of the commutation reactance is 0.15.
  • the transmission power of the VSC converter station is -450MW.
  • the load of the AC system connected to the VSC increases by 200MW, that is, the transmission power is -650MW, but the upper limit of the transmission capacity of the converter station is not reached
  • the VSC system still adopts amplitude and phase control.
  • the load of the AC system connected to the VSC increases by 150MW, that is, the transmission power is -800MW, reaching the upper limit of the transmission capacity of the converter station which is At this time, the control strategy of the converter station is switched to limit power control to ensure that the system power does not exceed the limit.
  • the AC system connected to the VSC removes 200MW of load, and the transmission power of the converter station is -600MW.
  • the transmission power is within the capacity of the converter station, and the converter station is switched to amplitude-phase control at this time.
  • the AC system connected to the VSC removes 150MW of load, the transmission power of the converter station is -450MW, and the system returns to a stable state.
  • Fig. 5 represents the transmission power of the VSC converter station.
  • the control mode can be selected according to the transmission capacity of the converter station to ensure the power stability of the system.
  • the converter station still maintains the amplitude and phase control.
  • the converter station automatically switches to limit power control to keep the power of the system stable.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

本发明提出一种适用于电压源型换流器的限功率方法，依据换流站传输功率，在传输功率超出换流站容量时，将换流站由原始控制策略切换为限功率控制方式，限制换流站的传输功率，保证系统功率不越限。当换流站传输功率恢复正常时，换流站重新切换为原始控制策略。本发明方法根据换流站传输容量上限，计算Pcc点和换流站交流出口侧电压的相角差，进而调整换流站交流出口侧电压的相角，保证二者相角同步变化，进而达到限功率作用。本发明能够有效约束功率，解决电压源型换流器采用幅相控制，幅频控制，有功无功耦合控制或定交流电压控制等策略来稳定交流电压时无法约束功率的问题；同时能最大限度利用换流器容量，提高了直流系统的安全性和稳定性。

Description

一种适用于电压源型换流器的限功率方法 技术领域
本发明属于电力系统技术领域，涉及一种适用于电压源型换流器的限功率方法。
背景技术
随着电力电子技术的发展，基于电压源换流器的高压直流输电也就是柔性直流输电得到了越来越广泛的应用。柔性直流输电因其可以实现有功无功解耦控制、向无源网络供电、能够提供无功支撑等优点，广泛地应用于风电汇集等新能源汇集场景。
随着新能源的广泛接入，新能源场景受到了越来越多的关注，风电场的交流电压受负荷影响较大，容易出现波动，在这种情况下压源型换流器采用原有控制策略(如幅相控制、幅频控制、有功无功耦合控制或定交流电压控制等策略)在稳定系统交流电压时无法有效约束线路功率，系统整体稳定性不佳。
发明内容：
为保证电力系统的稳定性，同时能最大限度利用换流器容量，本发明基于换流站容量设置限功率策略，提出一种适用于电压源型换流器的限功率方法，依据换流站传输功率，在传输功率超出换流站容量时，将换流站由原始控制策略切换为限功率控制方式，限制换流站的传输功率，保证系统功率不越限。当换流站传输功率恢复正常时，换流站重新切换为原始控制策略。
为了达到上述目的，本发明提出了一种适用于电压源型换流器的限功率方法，包括以下步骤：
当换流站传输功率超出换流站传输功率上限时，将换流站由原始控制策略切换为限功率控制方式，限制换流站的传输功率；
当换流站传输功率恢复正常时，将换流站重新切换为原始控制策略。
进一步的，所述将换流站由原始控制策略切换为限功率控制方式的过程为：根据换流站传输容量上限，计算在传输容量限值时Pcc点和换流站交流出口侧电 压的相角差，进而调整换流站交流出口侧电压的相角，保证二者相角同步变化，从而限制换流站的传输功率。
进一步的，所述将换流站由原始控制策略切换为限功率控制方式的过程具体包括如下步骤：
当原始控制策略为定交流电压控制时，通过给定定交流电压控制器内环输出值实现限功率，包括：
当换流站传输功率P s超出
Figure PCTCN2020116989-appb-000001
则切换为限功率控制后，定交流电压控制器输出指令整定为：
Figure PCTCN2020116989-appb-000002
当传输功率P s超出
Figure PCTCN2020116989-appb-000003
则切换为限功率控制后，定交流电压控制器输出指令整定为：
Figure PCTCN2020116989-appb-000004
当换流站传输功率恢复正常时，即换流站传输功率满足
Figure PCTCN2020116989-appb-000005
换流站重新切换为原始控制策略；
其中，
Figure PCTCN2020116989-appb-000006
和
Figure PCTCN2020116989-appb-000007
为换流站传输功率最大值，其中
Figure PCTCN2020116989-appb-000008
代表整流方向传输功率最大值，即代表有功功率由交流系统注入换流站；
Figure PCTCN2020116989-appb-000009
代表逆变方向传输功率最大值，即有功功率由换流站注入交流系统。U cd和U cq是换流站交流侧出口电压的dq轴分量，X c是换流站的换流电抗，U s是公共连接点处的交流电压幅值，U c是换流站交流侧出口处的交流电压幅值。
进一步的，当原始控制策略为幅相控制、幅频控制或有功无功耦合控制时，同时给定换流站交流电压的幅值和相角实现限功率，具体包括如下步骤：
当换流站传输功率P s超出
Figure PCTCN2020116989-appb-000010
则切换为限功率控制后，Pcc点电压幅值、 频率、相角以及交流侧出口电压相角指令整定为：
Figure PCTCN2020116989-appb-000011
当换流站传输功率P s超出
Figure PCTCN2020116989-appb-000012
则切换为限功率控制后，Pcc点电压幅值、频率、相角以及交流侧出口电压相角指令整定为：
Figure PCTCN2020116989-appb-000013
其中M、f和θ sa为Pcc点的电压幅值、频率和相角指令，θ ca为交流侧出口电压相角(A相)指令，f s为交流系统频率。
进一步的，当采用原始控制策略控制换流站时，在dq旋转坐标系下则交流侧出口电压为：
Figure PCTCN2020116989-appb-000014
其中s是拉普拉斯算子，U sd和U sq是公共连接点交流电压的dq轴分量，U cd和U cq是换流站交流侧出口电压的dq轴分量，i sd和i sq是换流站交流侧电流的dq轴分量，k p和k i是比例积分器的比例系数和积分系数，R c和X c是换流站的等效电阻和换流电抗；
从公共连接点处注入换流器交流侧出口的功率为：
Figure PCTCN2020116989-appb-000015
其中，P s和Q s是公共连接点处注入的有功功率和无功功率；U s是公共连接 点处的交流电压幅值，U c是换流站交流侧出口处的交流电压幅值；δ是U s和U c的相角差。
进一步的，所述当换流站传输功率恢复正常时，指换流站传输功率满足
Figure PCTCN2020116989-appb-000016
进一步的，所述原始控制策略通过换流器控制所连接交流系统公共连接点处或换流器交流出口处的交流电压的幅值、频率和相位。
进一步的，所述原始控制策略为以下策略中的一种：幅相控制、幅频控制、有功无功耦合控制、定交流电压控制。
进一步的，所述原始控制策略基于系统结构确定。
与现有技术相比，本发明具有如下优点和有益效果：
本发明方法根据换流站传输容量上限，计算Pcc点和换流站交流出口侧电压的相角差，进而调整换流站交流出口侧电压的相角，保证二者相角同步变化，从而达到限功率作用。本发明方法能够有效约束功率，解决电压源型换流器采用幅相控制，幅频控制，有功无功耦合控制和定交流电压控制等策略来稳定交流电压时无法约束功率的问题；同时能最大限度利用换流器容量，提高了直流系统的安全性和稳定性。
附图说明：
图1为应用本发明方法的单端VSC系统原理图，以定交流电压控制为例。
图2为应用本发明方法的双端VSC系统结构示意图。
图3为定交流电压控制结构图，其中(a)为d轴控制结构图，(b)为q轴控制结构图。
图4为幅相控制结构图。
图5为柔性直流输电系统仿真模型结构图。
图6为换流站传输功率仿真波形。
具体实施方式：
以下将结合具体实施例对本发明提供的技术方案进行详细说明，应理解下 述具体实施方式仅用于说明本发明而不用于限制本发明的范围。
本发明提供的适用于电压源型换流器的限功率方法，应用于如图1、图2所示的系统中，包括如下步骤：
步骤1：针对系统结构，确定系统的原始控制策略；
步骤2：当系统的原始控制策略为幅相控制(控制结构如图4所示)，幅频控制，有功无功耦合控制或定交流电压控制等(上述控制策略通过换流器控制所连接交流系统公共连接点(PCC点)处或换流器交流出口处的交流电压的幅值、频率和相位)时，在dq旋转坐标系下则交流侧出口电压为：
Figure PCTCN2020116989-appb-000017
其中s是拉普拉斯算子，U sd和U sq是公共连接点交流电压的dq轴分量，U cd和U cq是换流站交流侧出口电压的dq轴分量，i sd和i sq是换流站交流侧电流的dq轴分量，k p和k i是比例积分器的比例系数和积分系数，R c和X c是换流站的等效电阻和换流电抗。
从公共连接点(PCC点)处注入换流器交流侧出口的功率为：
Figure PCTCN2020116989-appb-000018
其中，P s和Q s是公共连接点(PCC点)处注入的有功功率和无功功率；U s是公共连接点处的交流电压幅值，U c是换流站交流侧出口处的交流电压幅值；δ是U s和U c的相角差。
步骤3：根据换流器容量，在传输功率超出换流站容量时，将换流站由原始控制策略切换为限功率控制方式，限制换流站的传输功率，保证系统功率不越限。
对换流站传输功率设置功率传输上限
Figure PCTCN2020116989-appb-000019
和
Figure PCTCN2020116989-appb-000020
检测调频换流站的传输功率，若传输功率不满足
Figure PCTCN2020116989-appb-000021
则换流站切换为限功率控制。
Figure PCTCN2020116989-appb-000022
和
Figure PCTCN2020116989-appb-000023
为换流站传输功率最大值，其中
Figure PCTCN2020116989-appb-000024
代表整流方向传输功率最大值，即代表有功功率由交流系统注入换流站；
Figure PCTCN2020116989-appb-000025
代表逆变方向传输功率最大值，即有功功率由换流站注入交流系统。本发明方法根据换流站传输容量上限，计算Pcc点和换流站交流出口侧电压的相角差，进而调整换流站交流出口侧电压的相角，保证二者相角同步变化，从而达到限功率作用。具体的说，包括如下步骤：
1)对于定交流电压控制器，如果换流站传输功率P s超出
Figure PCTCN2020116989-appb-000026
即换流站传输功率满足：
Figure PCTCN2020116989-appb-000027
则切换为限功率控制后，相角差
Figure PCTCN2020116989-appb-000028
为：
Figure PCTCN2020116989-appb-000029
控制器输出指令整定为：
Figure PCTCN2020116989-appb-000030
若换流站传输功率满足：
Figure PCTCN2020116989-appb-000031
则切换为限功率控制后，
相角差
Figure PCTCN2020116989-appb-000032
为：
Figure PCTCN2020116989-appb-000033
交流侧出口电压指令整定为：
Figure PCTCN2020116989-appb-000034
2)对于幅相控制、幅频控制或有功无功耦合控制时，给定换流站交流Pcc点电压幅值、频率和相角：
Figure PCTCN2020116989-appb-000035
其中M、f和θ sa为Pcc点的电压幅值、频率和相角(A相)指令，f s为交流系统频率。
如果换流站传输功率P s超过
Figure PCTCN2020116989-appb-000036
即换流站传输功率满足：
Figure PCTCN2020116989-appb-000037
在原控制基础上，对交流出口侧电压相角进行整定：
Figure PCTCN2020116989-appb-000038
若换流站传输功率满足：
Figure PCTCN2020116989-appb-000039
在原控制基础上，对交流出口侧电压相角进行整定：
Figure PCTCN2020116989-appb-000040
其中θ ca分别为交流侧出口电压相角(A相)指令。
步骤4：当换流站传输功率恢复正常时，即换流站传输功率满足
Figure PCTCN2020116989-appb-000041
换流站重新切换为原始控制策略，即步骤2中的控制策略。
采用图4所示的单端系统为例对本发明提出的限功率控制方法进行具体说明。VSC所连接的交流系统采用幅相控制，换流站的传输功率范围为-750MW≤P s≤750MW。
初始时刻，VSC换流站传输功率为-450MW。6s时，VSC所连交流系统负荷增加200MW，但未达到换流站传输容量上限
Figure PCTCN2020116989-appb-000042
16s时，VSC所连交流系统负荷增加150MW，达到换流站传输容量上限
Figure PCTCN2020116989-appb-000043
26s时，VSC所连交流系统切除200MW负荷。36s时，VSC所连交流系统切除150MW负荷，系统重新回到稳定状态。所搭建的仿真系统中，功率基准值为750MVA，交流电压基准值为500kV，直流电压基准值为500kV，换流电抗的标幺值为0.15。
对于本发明所采取的限功率控制策略：
初始时刻，VSC换流站传输功率为-450MW。
1s时，VSC所连交流系统负荷增加200MW，即传输功率为-650MW，但未达到换流站传输容量上限
Figure PCTCN2020116989-appb-000044
VSC系统仍采取幅相控制。
11s时，VSC所连交流系统负荷增加150MW，即传输功率为-800MW，达到换流站传输容量上限
Figure PCTCN2020116989-appb-000045
即
Figure PCTCN2020116989-appb-000046
此时换流站控制策略切换为限功率控制，保证系统功率不越限。
21s时，VSC所连交流系统切除200MW负荷，换流站传输功率为-600MW。传输功率在换流站容量范围内，此时换流站重新切换为幅相控制。
31s时，VSC所连交流系统切除150MW负荷，换流站传输功率为-450MW，系统重新回到稳定状态。
仿真波形如图5所示，图5代表VSC换流站传输功率。
由图可以看出，对于本发明所提出的限功率策略。当系统负荷发生变化时，能够根据换流站的传输容量选择控制方式，保证系统的功率稳定。在传输功率未达到换流站限值时，换流站仍保持幅相控制。当传输功率超出换流站限值时，换流站自动切换为限功率控制，以保持系统的功率稳定。
以上仿真验证了本发明提出的限功率策略的有效性，在传输功率超出换流站限值时，能够约束换流站传输功率。
本发明方案所公开的技术手段不仅限于上述实施方式所公开的技术手段，还包括由以上技术特征任意组合所组成的技术方案。应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也视为本发明的保护范围。

Claims (9)

  1. 一种适用于电压源型换流器的限功率方法，其特征在于，包括以下步骤：
    当换流站传输功率超出换流站传输功率上限时，将换流站由原始控制策略切换为限功率控制方式，限制换流站的传输功率；
    当换流站传输功率恢复正常时，将换流站重新切换为原始控制策略。
  2. 根据权利要求1所述的适用于电压源型换流器的限功率方法，其特征在于，所述将换流站由原始控制策略切换为限功率控制方式的过程为：根据换流站传输容量上限，计算在传输容量限值时Pcc点和换流站交流出口侧电压的相角差，进而调整换流站交流出口侧电压的相角，保证二者相角同步变化，从而限制换流站的传输功率。
  3. 根据权利要求2所述的适用于电压源型换流器的限功率方法，其特征在于，所述将换流站由原始控制策略切换为限功率控制方式的过程具体包括如下步骤：
    当原始控制策略为定交流电压控制时，通过给定定交流电压控制器内环输出值实现限功率，包括：
    当换流站传输功率P s超出
    Figure PCTCN2020116989-appb-100001
    则切换为限功率控制后，定交流电压控制器输出指令整定为：
    Figure PCTCN2020116989-appb-100002
    当传输功率P s超出
    Figure PCTCN2020116989-appb-100003
    则切换为限功率控制后，定交流电压控制器输出指令整定为：
    Figure PCTCN2020116989-appb-100004
    当换流站传输功率恢复正常时，即换流站传输功率满足
    Figure PCTCN2020116989-appb-100005
    换流站重新切换为原始控制策略；
    其中，
    Figure PCTCN2020116989-appb-100006
    和
    Figure PCTCN2020116989-appb-100007
    为换流站传输功率最大值，其中
    Figure PCTCN2020116989-appb-100008
    代表整流方向传输功率最大值，即代表有功功率由交流系统注入换流站；
    Figure PCTCN2020116989-appb-100009
    代表逆变方向传输功率最大值，即有功功率由换流站注入交流系统；U cd和U cq是换流站交流侧出口电压的dq轴分量，X c是换流站的换流电抗，U s是公共连接点处的交流电压幅值，U c是换流站交流侧出口处的交流电压幅值。
  4. 根据权利要求2所述的适用于电压源型换流器的限功率方法，其特征在于，当原始控制策略为幅相控制、幅频控制或有功无功耦合控制时，同时给定换流站交流电压的幅值和相角实现限功率，具体包括如下步骤：
    当换流站传输功率P s超出
    Figure PCTCN2020116989-appb-100010
    则切换为限功率控制后，Pcc点电压幅值、频率、相角以及交流侧出口电压相角指令整定为：
    Figure PCTCN2020116989-appb-100011
    当换流站传输功率P s超出
    Figure PCTCN2020116989-appb-100012
    则切换为限功率控制后，Pcc点电压幅值、频率、相角以及交流侧出口电压相角指令整定为：
    Figure PCTCN2020116989-appb-100013
    其中M、f和θ sa为Pcc点的电压幅值、频率和相角指令，θ ca为交流侧出口电压A相相角指令，f s为交流系统频率。
  5. 根据权利要求1所述的适用于电压源型换流器的限功率方法，其特征在于，当采用原始控制策略控制换流站时，在dq旋转坐标系下则交流侧出口电压为：
    Figure PCTCN2020116989-appb-100014
    其中s是拉普拉斯算子，U sd和U sq是公共连接点交流电压的dq轴分量，U cd和U cq 是换流站交流侧出口电压的dq轴分量，i sd和i sq是换流站交流侧电流的dq轴分量，k p和k i是比例积分器的比例系数和积分系数，R c和X c是换流站的等效电阻和换流电抗；
    从公共连接点处注入换流器交流侧出口的功率为：
    Figure PCTCN2020116989-appb-100015
    其中，P s和Q s是公共连接点处注入的有功功率和无功功率；U s是公共连接点处的交流电压幅值，U c是换流站交流侧出口处的交流电压幅值；δ是U s和U c的相角差。
  6. 根据权利要求1所述的适用于电压源型换流器的限功率方法，其特征在于，所述当换流站传输功率恢复正常时，指换流站传输功率满足
    Figure PCTCN2020116989-appb-100016
  7. 根据权利要求1所述的适用于电压源型换流器的限功率方法，其特征在于，所述原始控制策略通过换流器控制所连接交流系统公共连接点处或换流器交流出口处的交流电压的幅值、频率和相位。
  8. 根据权利要求1所述的适用于电压源型换流器的限功率方法，其特征在于，所述原始控制策略为以下策略中的一种：幅相控制、幅频控制、有功无功耦合控制、定交流电压控制。
  9. 根据权利要求1所述的适用于电压源型换流器的限功率方法，其特征在于，所述原始控制策略基于系统结构确定。
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105703381A (zh) * 2015-11-27 2016-06-22 华北电力大学 一种适用于vsc-hvdc联接极弱交流电网的功率阻尼同步控制方法
CN108599200A (zh) * 2018-05-17 2018-09-28 东南大学 孤岛新能源经真双极柔直电网接入的紧急限功率控制方法
CN109638839A (zh) * 2019-01-21 2019-04-16 东南大学 一种双极柔性直流输电系统潮流计算方法

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105914773A (zh) * 2016-05-16 2016-08-31 浙江大学 一种确定不对称交流电压下换流器交流侧功率极限的方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105703381A (zh) * 2015-11-27 2016-06-22 华北电力大学 一种适用于vsc-hvdc联接极弱交流电网的功率阻尼同步控制方法
CN108599200A (zh) * 2018-05-17 2018-09-28 东南大学 孤岛新能源经真双极柔直电网接入的紧急限功率控制方法
CN109638839A (zh) * 2019-01-21 2019-04-16 东南大学 一种双极柔性直流输电系统潮流计算方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
LI, YAZHOU: "Research on AC and DC Voltage Stability Control Strategies for VSC-MTDC System", ENGINEERING SCIENCE AND TECHNOLOGY II, CHINA MASTER'S THESES FULL-TEXT DATABASE, no. 6, 15 June 2020 (2020-06-15), pages 1 - 68, XP055904884, ISSN: 1674-0246 *

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