CN106786714A - A kind of asynchronous power network direct current locking dynamic frequency monitoring and Security Checking method - Google Patents

A kind of asynchronous power network direct current locking dynamic frequency monitoring and Security Checking method Download PDF

Info

Publication number
CN106786714A
CN106786714A CN201611117229.9A CN201611117229A CN106786714A CN 106786714 A CN106786714 A CN 106786714A CN 201611117229 A CN201611117229 A CN 201611117229A CN 106786714 A CN106786714 A CN 106786714A
Authority
CN
China
Prior art keywords
frequency
power grid
current line
direct current
power
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.)
Granted
Application number
CN201611117229.9A
Other languages
Chinese (zh)
Other versions
CN106786714B (en
Inventor
陈亦平
郑晓东
莫维科
侯君
张勇
陈巨龙
黄汉昌
楼楠
高琴
杨荣照
王子强
王巍
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.)
South China University of Technology SCUT
China Southern Power Grid Co Ltd
Original Assignee
South China University of Technology SCUT
China Southern Power Grid Co Ltd
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 South China University of Technology SCUT, China Southern Power Grid Co Ltd filed Critical South China University of Technology SCUT
Priority to CN201611117229.9A priority Critical patent/CN106786714B/en
Publication of CN106786714A publication Critical patent/CN106786714A/en
Application granted granted Critical
Publication of CN106786714B publication Critical patent/CN106786714B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for AC mains or AC distribution networks
    • H02J3/36Arrangements for transfer of electric power between AC networks via a high-tension DC link
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for AC mains or AC distribution networks
    • H02J3/36Arrangements for transfer of electric power between AC networks via a high-tension DC link
    • H02J2003/365Reducing harmonics or oscillations in HVDC
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Landscapes

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

Abstract

本发明公开了一种异步电网直流闭锁动态频率监测与安全校核方法,包括以下步骤:从能量管理系统获取所需的电网运行实时数据;分别将异步电网中的各回直流线路设定为双极闭锁状态;根据所需的电网运行实时数据,采用基于频率峰值估计的频率暂态分析方法,判断双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,是否会发生高频切机;根据高频切机的判断结果对各回直流线路进行相应的处理。本发明对异步联网中的多回直流线路分别设定了双极闭锁的故障场景并采用了基于频率峰值估计的频率暂态分析方法,能在线快速地计算各回直流线路双极闭锁后送端系统的频率峰值并进行高频切机判断,实时性好且更加快速,可广泛应用于电力领域。

The invention discloses a dynamic frequency monitoring and safety verification method for DC blocking of an asynchronous power grid, which comprises the following steps: acquiring required real-time data of power grid operation from an energy management system; setting each DC circuit in the asynchronous power grid as bipolar Blocking state: According to the required real-time data of power grid operation, the frequency transient analysis method based on frequency peak estimation is used to judge whether each circuit of DC lines after bipolar blocking will occur under the control of the system's frequency regulation and safety and stability scheme High-frequency cutting machine: according to the judgment result of high-frequency cutting machine, corresponding processing is carried out for each DC circuit. The present invention respectively sets the bipolar blocking fault scenarios for the multi-circuit DC lines in the asynchronous networking and adopts the frequency transient analysis method based on the frequency peak estimation, which can quickly calculate the bipolar blocking of each DC line on line and send the end system The peak value of the frequency and the judgment of high-frequency cut-off, the real-time performance is better and faster, and can be widely used in the field of electric power.

Description

一种异步电网直流闭锁动态频率监测与安全校核方法A dynamic frequency monitoring and safety checking method for DC blocking of asynchronous power grid

技术领域technical field

本发明涉及电力领域,尤其是一种异步电网直流闭锁动态频率监测与安全校核方法。The invention relates to the field of electric power, in particular to a method for dynamic frequency monitoring and safety checking of asynchronous power grid DC blocking.

背景技术Background technique

随着高压直流输电技术的成熟发展,采用直流输电实现省间送电的方式日益普遍。以南方电网为例,其管辖范围内的云南电网,是一个大规模的电力送出系统,为了解决交流线路的功角稳定等问题,在2016年,南方电网将云南电网仅通过多回直流线路与由广东电网、广西电网、贵州电网以及海南电网组成的主网异步互联。With the mature development of high-voltage direct current transmission technology, the way of using direct current transmission to realize inter-provincial power transmission is becoming more and more common. Taking China Southern Power Grid as an example, the Yunnan Power Grid within its jurisdiction is a large-scale power transmission system. In order to solve problems such as the stability of the power angle of the AC line, in 2016, the China Southern Power Grid connected the Yunnan Power Grid only through multiple DC lines. The main grid composed of Guangdong Power Grid, Guangxi Power Grid, Guizhou Power Grid and Hainan Power Grid is asynchronously interconnected.

异步互联之后,云南电网的系统机械惯性减小,在同样的功率扰动下,其频率偏差将大于传统的大型同步电网。为了防止云南电网与主网之间的直流线路在发生单极闭锁或双极闭锁之后因频率超出限定值而引发高频切机,乃至频率失稳,云南电网的一次调频能力和直流过负荷能力应该符合安全要求,且其安全稳定方案设定的连锁切机应该合理。然而在实际运行中,异步电网的直流线路负载率和机组一次调频能力等工况是实时变化的,预先设置的安全稳定方案可能无法满足要求,因此,应该对异步电网的每条直流线路进行实时安全校核,快速估计出在目前工况下直流双极闭锁后送端系统(如云南电网的送端系统)的频率最高值,从而给调度运行提供有用的决策辅助信息。After asynchronous interconnection, the system mechanical inertia of Yunnan power grid is reduced, and its frequency deviation will be greater than that of traditional large-scale synchronous power grid under the same power disturbance. In order to prevent the DC line between Yunnan Power Grid and the main grid from being cut off due to frequency exceeding the limit value after unipolar blocking or bipolar blocking occurs, and even frequency instability, the primary frequency regulation capability and DC overload capacity of Yunnan Power Grid It should meet the safety requirements, and the chain cutting machine set in the safety and stability plan should be reasonable. However, in actual operation, the load rate of the DC line of the asynchronous grid and the primary frequency adjustment capability of the unit change in real time, and the preset security and stability scheme may not meet the requirements. Therefore, each DC line of the asynchronous grid should be monitored in real time. Safety check, quickly estimate the highest frequency value of the DC bipolar blocking sending end system (such as the sending end system of Yunnan Power Grid) under the current working conditions, so as to provide useful decision-making auxiliary information for dispatching operation.

发明内容Contents of the invention

为解决上述技术问题,本发明的目的在于:提供一种实时和快速的异步电网直流闭锁动态频率监测与安全校核方法。In order to solve the above-mentioned technical problems, the object of the present invention is to provide a real-time and fast method for dynamic frequency monitoring and safety checking of asynchronous power grid DC blocking.

本发明所采取的技术方案是:The technical scheme that the present invention takes is:

一种异步电网直流闭锁动态频率监测与安全校核方法,包括以下步骤:A method for dynamic frequency monitoring and safety verification of DC blocking in an asynchronous power grid, comprising the following steps:

从能量管理系统获取所需的电网运行实时数据;Obtain the required real-time data of power grid operation from the energy management system;

分别将异步电网中的各回直流线路设定为双极闭锁状态;Set each DC circuit in the asynchronous power grid to a bipolar blocking state;

根据所需的电网运行实时数据,采用基于频率峰值估计的频率暂态分析方法,判断双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,是否会发生高频切机;According to the required real-time data of power grid operation, the frequency transient analysis method based on frequency peak estimation is used to judge whether high-frequency switching will occur under the control of the system's frequency adjustment and safety and stability schemes for each circuit of DC lines after bipolar blocking. machine;

根据高频切机的判断结果对各回直流线路进行相应的处理:若当前回直流线路会发生高频切机,则发出告警信号,提示需要对当前回直流线路发生故障时的安稳措施或系统直流功率送出方案进行修改;反之,则表明当前回直流线路的运行状况满足安全要求,此时结束当前回直流线路的安全校核过程,其中,当前回直流线路为各回直流线路的任一回直流线路。According to the judgment result of high-frequency cut-off, corresponding processing will be carried out on each DC circuit: if the current DC circuit will have high-frequency cut-off, an alarm signal will be issued, prompting the need for safety measures or system DC circuits when the current DC circuit fails. On the contrary, it indicates that the operation status of the current return DC line meets the safety requirements, and the safety check process of the current return DC line is ended at this time, wherein the current return DC line is any return DC line of each return DC line .

进一步,所述所需的电网运行实时数据包括但不限于系统的一次调频备用、各回直流线路的额定输送功率、各回直流线路的闭锁连锁切机量、系统的当前送出功率、系统的转动惯量以及负荷频率响应。Further, the real-time data required for power grid operation include but are not limited to the primary frequency modulation backup of the system, the rated transmission power of each return DC line, the blocking chain cut-off capacity of each return DC line, the current output power of the system, the moment of inertia of the system, and load frequency response.

进一步,所述分别将异步电网中的各回直流线路设定为双极闭锁状态这一步骤,其具体为:Further, the step of respectively setting each DC circuit in the asynchronous power grid to a bipolar blocking state is specifically:

进行单一校核,将异步电网的每回直流线路依次设定为发生双极闭锁状态,以使得双极闭锁发生后的该回直流线路的送出功率降为零,且令双极闭锁发生后的该回直流线路相应安全稳定控制方案所设定的连锁切机和直流功率支援开始动作。Perform a single check, and set each DC line of the asynchronous power grid to the bipolar blocking state in turn, so that the output power of the DC line after the bipolar blocking occurs is reduced to zero, and the bipolar blocking occurs. The chain cut-off and DC power support set by the corresponding safety and stability control scheme of the DC line start to operate.

进一步,所述根据所需的电网运行实时数据,采用基于频率峰值估计的频率暂态分析方法,判断双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,是否会发生高频切机这一步骤,其包括:Further, according to the required real-time data of power grid operation, the frequency transient analysis method based on frequency peak estimation is used to judge whether the DC circuits after bipolar blocking are under the control of the system's frequency adjustment and safety and stability schemes. The step of high-frequency cutting occurs, which includes:

根据所需的电网运行实时数据,分析在系统一次调频、负荷频率响应和安全稳定措施作用下各回直流线路频率的响应过程,从而计算出各回直流线路的频率峰值;According to the required real-time data of power grid operation, analyze the frequency response process of each DC circuit under the action of system primary frequency regulation, load frequency response and safety and stability measures, so as to calculate the frequency peak value of each DC circuit;

将各回直流线路的频率峰值与系统高频切机的设定频率进行比较,并根据比较的结果判断双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,是否会发生高频切机。Compare the frequency peak value of each DC circuit with the set frequency of the system high-frequency cut-off machine, and judge according to the comparison results whether each DC circuit after bipolar blocking is under the control of the system's frequency adjustment and safety and stability scheme. A high frequency cut occurs.

进一步,所述根据所需的电网运行实时数据,分析在系统一次调频、负荷频率响应和安全稳定措施作用下各回直流线路频率的响应过程,从而计算出各回直流线路的频率峰值这一步骤,其包括:Further, according to the required real-time data of power grid operation, the step of analyzing the frequency response process of each DC circuit under the action of system primary frequency regulation, load frequency response and safety and stability measures, so as to calculate the frequency peak value of each DC circuit, includes include:

将系统等效为一台机组,根据所需的电网运行实时数据采用一阶微分方程描述系统频率偏差的动态过程,并通过时域仿真求解出系统频率偏差的时域表达式,所述系统频率偏差的时域表达式Δf(t)为:The system is equivalent to a unit, and the first-order differential equation is used to describe the dynamic process of the system frequency deviation according to the required real-time data of power grid operation, and the time domain expression of the system frequency deviation is solved through time domain simulation. The system frequency The time-domain expression Δf(t) of the deviation is:

其中, M=M′,t为时间,Pm0为正常运行或在直流线路双极闭锁发生前的瞬间发电机功率,ΔPG为连锁切机量,P0为正常运行或在直流线路双极闭锁发生前的负荷功率,ω0为正常运行或在直流线路双极闭锁发生前的瞬间发电机转速,KL为负荷的频率调节系数,f0为系统频率,为系统频率f0的KL次方,ΔPDC为直流功率提升量与直流线路因双极闭锁而少送的功率的代数和,为正常运行或在直流线路双极闭锁发生前的瞬间负荷功率,R′为连锁切机动作发生后系统一次调频的等效调差系数,r为连锁切机动作发生后系统运行中具有备用容量的机组序号,n为连锁切机动作发生后系统运行中全部机组的序号总数,(Pm0)r和(Pm0)n分别为序号为r和n的机组正常运行或在直流线路双极闭锁发生前的瞬间发电机功率,为连锁切机动作发生后序号为r的机组的单位调节功率,M=M′,M′为连锁切机动作发生后系统的等效惯性常数,T为时间常数;in, M=M', t is time, P m0 is normal operation or the instantaneous generator power before bipolar blocking of DC line, ΔP G is the amount of chain cutting, P 0 is normal operation or when bipolar blocking of DC line occurs The load power before , ω 0 is the normal operation or the instantaneous generator speed before the bipolar blocking of the DC line, K L is the frequency adjustment coefficient of the load, f 0 is the system frequency, is the K L power of the system frequency f 0 , ΔP DC is the algebraic sum of the DC power boost and the power less transmitted by the DC line due to bipolar blocking, is the instantaneous load power in normal operation or before the bipolar blockage of the DC line occurs, R' is the equivalent difference adjustment coefficient of the primary frequency modulation of the system after the chain cutting action occurs, r is the sequence number of the unit with spare capacity in the system operation after the chain cut-off action occurs, n is the total number of all units in the system operation after the chain cut-off action occurs, (P m0 ) r and (P m0 ) n are respectively the sequence numbers of The units r and n are in normal operation or the instantaneous generator power before the bipolar blocking of the DC line occurs, It is the unit adjustment power of the unit with serial number r after the chain cutting action occurs, M=M', M' is the equivalent inertia constant of the system after the chain cutting action occurs, and T is the time constant;

根据系统频率偏差Δf(t)的时域表达式得出各回直流线路的频率偏差峰值,所述各回直流线路的频率偏差峰值为时间t满足时对应的频率偏差值。According to the time-domain expression of the system frequency deviation Δf(t), the frequency deviation peak value of each DC circuit is obtained, and the frequency deviation peak value of each DC circuit satisfies the time t The corresponding frequency deviation value.

进一步,所述将系统等效为一台机组,根据所需的电网运行实时数据采用一阶微分方程描述系统频率偏差的动态过程,并通过时域仿真求解出系统频率偏差的时域表达式这一步骤,其包括:Further, the system is equivalent to a unit, and the first-order differential equation is used to describe the dynamic process of the system frequency deviation according to the required real-time data of power grid operation, and the time domain expression of the system frequency deviation is obtained through time domain simulation. A step, which includes:

将系统等效为一台机组,根据所需的电网运行实时数据采用一阶微分方程描述系统频率偏差的动态过程,所述系统频率偏差的动态过程描述方程为:The system is equivalent to a unit, and the first-order differential equation is used to describe the dynamic process of the system frequency deviation according to the required real-time data of power grid operation. The dynamic process description equation of the system frequency deviation is:

其中,β(t)为阶跃输入,Δω为系统输出的转速偏差, Among them, β(t) is the step input, Δω is the rotational speed deviation of the system output,

采用拉普拉斯变换对系统频率偏差的动态过程描述方程进行求解,得到系统的拉普拉斯转速偏差Δω(s),所述系统的拉普拉斯转速偏差Δω(s)的表达式为:The Laplace transform is used to solve the dynamic process description equation of the system frequency deviation, and the Laplace rotational speed deviation Δω(s) of the system is obtained. The expression of the Laplace rotational speed deviation Δω(s) of the system is: :

其中,s为拉普拉斯算子;Among them, s is the Laplacian operator;

根据系统的拉普拉斯转速偏差Δω(s)进行时域仿真,计算出系统频率偏差的时域表达式Δf(t)。According to the Laplace speed deviation Δω(s) of the system, the time-domain simulation is carried out, and the time-domain expression Δf(t) of the system frequency deviation is calculated.

进一步,所述将各回直流线路的频率峰值与系统高频切机的设定频率进行比较,并根据比较的结果判断双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,是否会发生高频切机这一步骤,其具体为:Further, the frequency peak value of each DC circuit is compared with the set frequency of the system high-frequency cut-off machine, and according to the comparison result, it is judged that each DC circuit after bipolar blocking has a control effect on the frequency regulation of the system and the safety and stability scheme Next, whether the step of high-frequency cutting will occur, specifically:

若各回直流线路的频率峰值超过系统高频切机的设定频率,则判定双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,会发生高频切机;反之,则判定双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,不会发生高频切机。If the peak frequency of each DC circuit exceeds the set frequency of the high-frequency cut-off of the system, it is determined that the high-frequency cut-off will occur in each DC circuit after bipolar blocking under the control of the system's frequency adjustment and safety and stability scheme; otherwise , it is determined that the DC circuits after the bipolar block will not have high-frequency cut-off under the control of the system's frequency regulation and safety and stability scheme.

进一步,所述对当前回直流线路发生故障时的安稳措施或系统直流功率送出方案进行修改这一过程所执行的操作包括但不限于:降低当前回直流线路的送电功率;增加连锁切机量;增加一次调频旋转备用容量;连锁切机优先切除转动惯量小、容量大或具有反调作用的水电机组。Further, the operations performed in the process of modifying the safety measures or system DC power transmission scheme when the current back-to-DC line fails include but are not limited to: reducing the power transmission power of the current back-to-DC line; increasing the amount of chain cut-off; Increase the reserve capacity of a frequency modulation rotation; the chain cutting machine preferentially removes hydroelectric units with small moment of inertia, large capacity or reverse modulation.

本发明的有益效果是:包括获取所需的电网运行实时数据,分别将异步电网中的各回直流线路设定为双极闭锁状态;根据所需的电网运行实时数据,采用基于频率峰值估计的频率暂态分析方法判断是否会发生高频切机以及根据高频切机的判断结果对各回直流线路进行相应的处理过程,对异步联网中的多回直流线路分别设定了双极闭锁的故障场景并采用了基于频率峰值估计的频率暂态分析方法,能在线快速地计算各回直流线路双极闭锁后送端系统的频率峰值并根据计算的频率峰值进行高频切机判断,为异步电网系统的运行方式和实时调度提供了校验和决策辅助信息,避免了直流线路因双极闭锁故障而导致送端系统的频率超过安全限制的现象发生,实时性好且更加快速。The beneficial effects of the present invention are: including obtaining the required real-time data of power grid operation, respectively setting each DC circuit in the asynchronous power grid to a bipolar blocking state; according to the required real-time data of power grid operation, using a frequency based on frequency peak estimation The transient analysis method judges whether high-frequency cut-off will occur and performs corresponding processing on each DC line according to the judgment result of high-frequency cut-off, and sets the fault scenarios of bipolar blocking for multi-circuit DC lines in asynchronous networking. And the frequency transient analysis method based on the frequency peak estimation is adopted, which can quickly calculate the frequency peak value of the sending end system after bipolar blocking of each DC line on line, and judge the high-frequency cut-off according to the calculated frequency peak value, which is an asynchronous power grid system. The operation mode and real-time scheduling provide auxiliary information for verification and decision-making, which avoids the phenomenon that the frequency of the sending end system exceeds the safety limit due to the bipolar blocking fault of the DC line, and the real-time performance is good and faster.

附图说明Description of drawings

图1为本发明一种异步电网直流闭锁动态频率监测与安全校核方法的整体流程图;Fig. 1 is the overall flow chart of a kind of asynchronous power grid DC blocking dynamic frequency monitoring and safety checking method of the present invention;

图2为本发明直流闭锁频率动态响应的传递函数框图;Fig. 2 is the transfer function block diagram of DC blocking frequency dynamic response of the present invention;

图3为采用本发明的方法得到的频率动态计算曲线示意图。Fig. 3 is a schematic diagram of frequency dynamic calculation curve obtained by adopting the method of the present invention.

具体实施方式detailed description

参照图1,一种异步电网直流闭锁动态频率监测与安全校核方法,包括以下步骤:Referring to Fig. 1, a method for dynamic frequency monitoring and safety verification of DC blocking of an asynchronous power grid includes the following steps:

从能量管理系统获取所需的电网运行实时数据;Obtain the required real-time data of power grid operation from the energy management system;

分别将异步电网中的各回直流线路设定为双极闭锁状态;Set each DC circuit in the asynchronous power grid to a bipolar blocking state;

根据所需的电网运行实时数据,采用基于频率峰值估计的频率暂态分析方法,判断双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,是否会发生高频切机;According to the required real-time data of power grid operation, the frequency transient analysis method based on frequency peak estimation is used to judge whether high-frequency switching will occur under the control of the system's frequency adjustment and safety and stability schemes for each circuit of DC lines after bipolar blocking. machine;

根据高频切机的判断结果对各回直流线路进行相应的处理:若当前回直流线路会发生高频切机,则发出告警信号,提示需要对当前回直流线路发生故障时的安稳措施或系统直流功率送出方案进行修改;反之,则表明当前回直流线路的运行状况满足安全要求,此时结束当前回直流线路的安全校核过程,其中,当前回直流线路为各回直流线路的任一回直流线路。According to the judgment result of high-frequency cut-off, corresponding processing will be carried out on each DC circuit: if the current DC circuit will have high-frequency cut-off, an alarm signal will be issued, prompting the need for safety measures or system DC circuits when the current DC circuit fails. On the contrary, it indicates that the operation status of the current return DC line meets the safety requirements, and the safety check process of the current return DC line is ended at this time, wherein the current return DC line is any return DC line of each return DC line .

进一步作为优选的实施方式,所述所需的电网运行实时数据包括但不限于系统的一次调频备用、各回直流线路的额定输送功率、各回直流线路的闭锁连锁切机量、系统的当前送出功率、系统的转动惯量以及负荷频率响应。As a further preferred embodiment, the required real-time data on power grid operation includes but is not limited to the primary frequency modulation backup of the system, the rated transmission power of each DC circuit, the blocking chain cut-off capacity of each DC circuit, the current output power of the system, The moment of inertia of the system and the frequency response of the load.

进一步作为优选的实施方式,所述分别将异步电网中的各回直流线路设定为双极闭锁状态这一步骤,其具体为:As a further preferred embodiment, the step of setting each DC circuit in the asynchronous power grid to a bipolar blocking state is specifically:

进行单一校核,将异步电网的每回直流线路依次设定为发生双极闭锁状态,以使得双极闭锁发生后的该回直流线路的送出功率降为零,且令双极闭锁发生后的该回直流线路相应安全稳定控制方案所设定的连锁切机和直流功率支援开始动作。Perform a single check, and set each DC line of the asynchronous power grid to the bipolar blocking state in turn, so that the output power of the DC line after the bipolar blocking occurs is reduced to zero, and the bipolar blocking occurs. The chain cut-off and DC power support set by the corresponding safety and stability control scheme of the DC line start to operate.

进一步作为优选的实施方式,所述根据所需的电网运行实时数据,采用基于频率峰值估计的频率暂态分析方法,判断双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,是否会发生高频切机这一步骤,其包括:As a further preferred embodiment, according to the required real-time data of power grid operation, the frequency transient analysis method based on frequency peak estimation is used to judge the frequency adjustment of each DC circuit after bipolar blocking and the control of the safety and stability scheme in the system Under the action, whether the step of high-frequency cutting will occur, which includes:

根据所需的电网运行实时数据,分析在系统一次调频、负荷频率响应和安全稳定措施作用下各回直流线路频率的响应过程,从而计算出各回直流线路的频率峰值;According to the required real-time data of power grid operation, analyze the frequency response process of each DC circuit under the action of system primary frequency regulation, load frequency response and safety and stability measures, so as to calculate the frequency peak value of each DC circuit;

将各回直流线路的频率峰值与系统高频切机的设定频率进行比较,并根据比较的结果判断双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,是否会发生高频切机。Compare the frequency peak value of each DC circuit with the set frequency of the system high-frequency cut-off machine, and judge according to the comparison results whether each DC circuit after bipolar blocking is under the control of the system's frequency adjustment and safety and stability scheme. A high frequency cut occurs.

进一步作为优选的实施方式,所述根据所需的电网运行实时数据,分析在系统一次调频、负荷频率响应和安全稳定措施作用下各回直流线路频率的响应过程,从而计算出各回直流线路的频率峰值这一步骤,其包括:As a further preferred embodiment, according to the required real-time data of power grid operation, analyze the response process of the frequency of each DC circuit under the action of system primary frequency modulation, load frequency response and safety and stability measures, so as to calculate the peak frequency of each DC circuit This step, which includes:

将系统等效为一台机组,根据所需的电网运行实时数据采用一阶微分方程描述系统频率偏差的动态过程,并通过时域仿真求解出系统频率偏差的时域表达式,所述系统频率偏差的时域表达式Δf(t)为:The system is equivalent to a unit, and the first-order differential equation is used to describe the dynamic process of the system frequency deviation according to the required real-time data of power grid operation, and the time domain expression of the system frequency deviation is solved through time domain simulation. The system frequency The time-domain expression Δf(t) of the deviation is:

其中, M=M′,t为时间,Pm0为正常运行或在直流线路双极闭锁发生前的瞬间发电机功率,ΔPG为连锁切机量,P0为正常运行或在直流线路双极闭锁发生前的负荷功率,ω0为正常运行或在直流线路双极闭锁发生前的瞬间发电机转速,KL为负荷的频率调节系数,f0为系统频率,为系统频率f0的KL次方,ΔPDC为直流功率提升量与直流线路因双极闭锁而少送的功率的代数和,为正常运行或在直流线路双极闭锁发生前的瞬间负荷功率,R′为连锁切机动作发生后系统一次调频的等效调差系数,r为连锁切机动作发生后系统运行中具有备用容量的机组序号,n为连锁切机动作发生后系统运行中全部机组的序号总数,(Pm0)r和(Pm0)n分别为序号为r和n的机组正常运行或在直流线路双极闭锁发生前的瞬间发电机功率,为连锁切机动作发生后序号为r的机组的单位调节功率,M=M′,M′为连锁切机动作发生后系统的等效惯性常数,T为时间常数;in, M=M', t is time, P m0 is normal operation or the instantaneous generator power before bipolar blocking of DC line, ΔP G is the amount of chain cutting, P 0 is normal operation or when bipolar blocking of DC line occurs The load power before , ω 0 is the normal operation or the instantaneous generator speed before the bipolar blocking of the DC line, K L is the frequency adjustment coefficient of the load, f 0 is the system frequency, is the K L power of the system frequency f 0 , ΔP DC is the algebraic sum of the DC power boost and the power less transmitted by the DC line due to bipolar blocking, is the instantaneous load power in normal operation or before the bipolar blockage of the DC line occurs, R' is the equivalent difference adjustment coefficient of the primary frequency modulation of the system after the chain cutting action occurs, r is the sequence number of the unit with spare capacity in the system operation after the chain cut-off action occurs, n is the total number of all units in the system operation after the chain cut-off action occurs, (P m0 ) r and (P m0 ) n are respectively the sequence numbers of The instantaneous generator power of units r and n in normal operation or before bipolar blocking of the DC line occurs, It is the unit adjustment power of the unit with serial number r after the chain cutting action occurs, M=M', M' is the equivalent inertia constant of the system after the chain cutting action occurs, and T is the time constant;

根据系统频率偏差Δf(t)的时域表达式得出各回直流线路的频率偏差峰值,所述各回直流线路的频率偏差峰值为时间t满足时对应的频率偏差值。According to the time-domain expression of the system frequency deviation Δf(t), the frequency deviation peak value of each DC circuit is obtained, and the frequency deviation peak value of each DC circuit satisfies the time t The corresponding frequency deviation value.

进一步作为优选的实施方式,所述将系统等效为一台机组,根据所需的电网运行实时数据采用一阶微分方程描述系统频率偏差的动态过程,并通过时域仿真求解出系统频率偏差的时域表达式这一步骤,其包括:As a further preferred embodiment, the system is equivalent to a unit, and the first-order differential equation is used to describe the dynamic process of the system frequency deviation according to the required real-time data of power grid operation, and the system frequency deviation is solved by time domain simulation. The step of time domain expression, which includes:

将系统等效为一台机组,根据所需的电网运行实时数据采用一阶微分方程描述系统频率偏差的动态过程,所述系统频率偏差的动态过程描述方程为:The system is equivalent to a unit, and the first-order differential equation is used to describe the dynamic process of the system frequency deviation according to the required real-time data of power grid operation. The dynamic process description equation of the system frequency deviation is:

其中,β(t)为阶跃输入,Δω为系统输出的转速偏差, Among them, β(t) is the step input, Δω is the rotational speed deviation of the system output,

采用拉普拉斯变换对系统频率偏差的动态过程描述方程进行求解,得到系统的拉普拉斯转速偏差Δω(s),所述系统的拉普拉斯转速偏差Δω(s)的表达式为:The Laplace transform is used to solve the dynamic process description equation of the system frequency deviation, and the Laplace rotational speed deviation Δω(s) of the system is obtained. The expression of the Laplace rotational speed deviation Δω(s) of the system is: :

其中,s为拉普拉斯算子;Among them, s is the Laplacian operator;

根据系统的拉普拉斯转速偏差Δω(s)进行时域仿真,计算出系统频率偏差的时域表达式Δf(t)。According to the Laplace speed deviation Δω(s) of the system, the time-domain simulation is carried out, and the time-domain expression Δf(t) of the system frequency deviation is calculated.

进一步作为优选的实施方式,所述将各回直流线路的频率峰值与系统高频切机的设定频率进行比较,并根据比较的结果判断双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,是否会发生高频切机这一步骤,其具体为:As a further preferred embodiment, the frequency peak value of each return DC line is compared with the set frequency of the system high-frequency cut-off machine, and the frequency adjustment and safety of each return DC line in the system after bipolar blocking are judged according to the comparison result. Under the control of the stabilization scheme, whether the step of high-frequency cutting will occur, specifically:

若各回直流线路的频率峰值超过系统高频切机的设定频率,则判定双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,会发生高频切机;反之,则判定双极闭锁后的各回直流线路在系统的频率调节和安全稳定方案的控制作用下,不会发生高频切机。If the peak frequency of each DC circuit exceeds the set frequency of the high-frequency cut-off of the system, it is determined that the high-frequency cut-off will occur in each DC circuit after bipolar blocking under the control of the system's frequency adjustment and safety and stability scheme; otherwise , it is determined that the DC circuits after the bipolar block will not have high-frequency cut-off under the control of the system's frequency regulation and safety and stability scheme.

进一步作为优选的实施方式,所述对当前回直流线路发生故障时的安稳措施或系统直流功率送出方案进行修改这一过程所执行的操作包括但不限于:降低当前回直流线路的送电功率;增加连锁切机量;增加一次调频旋转备用容量;连锁切机优先切除转动惯量小、容量大或具有反调作用的水电机组。As a further preferred embodiment, the operations performed in the process of modifying the safety measures or the system DC power sending scheme when the current back-to-DC line fails include but are not limited to: reducing the power transmission power of the current back-to-DC line; increasing The amount of chain cut-off; increase the reserve capacity of a frequency modulation rotation; the chain cut-off priority cuts off the hydropower units with small moment of inertia, large capacity or reverse modulation.

下面结合说明书附图和具体实施例对本发明作进一步解释和说明。The present invention will be further explained and described below in conjunction with the accompanying drawings and specific embodiments of the description.

实施例一Embodiment one

针对现有技术实时性差且不够快速的问题,本发明提出了一种异步电网直流闭锁动态频率监测与安全校核方法。该方法能在线快速地计算各回直流线路双极闭锁后,送端系统的频率峰值,从而给异步电网系统的调度运行提供了有用的决策辅助信息。Aiming at the problems of poor real-time performance and insufficient speed in the prior art, the present invention proposes a dynamic frequency monitoring and safety checking method for DC blocking of an asynchronous power grid. This method can quickly calculate the peak frequency of the sending end system after bipolar blocking of each DC line on-line, thus providing useful decision-making auxiliary information for the dispatching operation of the asynchronous power grid system.

如图1所示,本发明的异步电网直流闭锁动态频率监测与安全校核方法的具体过程如下:As shown in Figure 1, the specific process of the asynchronous power grid DC blocking dynamic frequency monitoring and safety checking method of the present invention is as follows:

(一)获取所需的电网运行实时数据。所需的电网运行实时数据包括但不限于系统的一次调频备用、各回直流线路的额定输送功率、各回直流线路的闭锁连锁切机量、系统的当前送出功率、系统的转动惯量以及负荷频率响应。所需的电网运行实时数据可从SCADA系统(即数据采集与监视控制系统,能量管理系统的一个子系统)中获取。(1) Obtain the required real-time data of power grid operation. The real-time data required for power grid operation include but are not limited to the primary frequency regulation backup of the system, the rated transmission power of each DC circuit, the blocking chain cut-off capacity of each DC circuit, the current output power of the system, the moment of inertia of the system, and the load frequency response. The required real-time data of power grid operation can be obtained from the SCADA system (that is, the data acquisition and monitoring control system, a subsystem of the energy management system).

(二)依次将每回直流线路设定为双极闭锁状态。(2) Set each DC line in sequence to a bipolar blocking state.

(三)通过频率暂态分析方法,判断该回直流线路闭锁后在系统频率调节作用和安全稳定控制下,是否会发生高频切机。(3) Through the frequency transient analysis method, it is judged whether high-frequency cut-off will occur under the system frequency adjustment function and safety and stability control after the DC return line is blocked.

频率暂态过程分析是基于系统的运行方程,综合考虑系统惯性、直流功率支援、连锁切机、一次调频和负荷频率调节效用等作用,用微分方程进行描述和求解的。系统的运行方程如下:The analysis of the frequency transient process is based on the operating equation of the system, comprehensively considering the effects of system inertia, DC power support, chain cut-off, primary frequency modulation and load frequency regulation, etc., and is described and solved by differential equations. The operating equation of the system is as follows:

其中,J为系统的等效转动惯量;Tm为机械转矩;Te为电磁转矩;Pm为发电机的电功率;PL为负荷电功率,PL包括直流外送功率;ω为发电机转速,表征系统的频率。Among them, J is the equivalent moment of inertia of the system; T m is the mechanical torque; T e is the electromagnetic torque; P m is the electric power of the generator; P L is the load electric power, P L includes the DC output power; The machine speed represents the frequency of the system.

设正常运行或在直流闭锁事件发生前的瞬间,转速为ω0,发电机功率为负荷功率为而直流闭锁事件发生后的初瞬间,三者分别为 直流闭锁事件发生后的转速 其中,f为频率,且ω=2πf;KL是负荷的频率调节系数,计及正常运行条件下直流线路的频率调节作用,KL一般在1-3间;ΔPG为连锁切机量;ΔPDC为直流功率提升量与直流线路因闭锁而少送的功率的代数和。Assume that during normal operation or at the instant before the DC blocking event occurs, the rotational speed is ω 0 , and the generator power is The load power is And at the first instant after the DC blocking event, the three are respectively Speed after DC blocking event Among them, f is the frequency, and ω=2πf; K L is the frequency adjustment coefficient of the load, taking into account the frequency adjustment effect of the DC line under normal operating conditions, K L is generally between 1-3; ΔP G is the amount of chain cut; ΔP DC is the algebraic sum of the DC power boost and the power less sent by the DC line due to blocking.

均为直流闭锁事件发生后初瞬间的转矩值。则有:Assume with Both are the torque values at the initial instant after the DC blocking event occurs. Then there are:

考虑到系统的部分发电机组有旋转备用,当将全系统发电容量等价为一台发电机时,该等价发电机的单位调节功率将为:Considering that some generator sets of the system have spinning reserves, when the power generation capacity of the whole system is equivalent to a generator, the unit regulation power of the equivalent generator will be:

式中,下标r代表运行中具有备用容量的机组序号,n代表运行中全部机组的序号总数。当双极闭锁故障发生后由于连锁切机动作,系统机组的运行情况将发生变化,所以其单位调节功率需重新计算,记为这同样适用于转动惯量J或惯性常数M0,当连锁切机发生后,系统的等效惯性常数应重新计算,且记为M'=J'ω0。本发明系统等效惯性常数M'、一次调频的等效调差系数R'和时间常数T,必须根据连锁切机后电网的机组运行状态进行计算。而系统的一次调频参数还必须根据系统一次调频机组的旋转备用容量以及各类型机组(包括水轮发电机组、无再热式和再热式汽轮发电机组等)的比例进行等效计算。In the formula, the subscript r represents the serial number of the unit with spare capacity in operation, and n represents the total number of all units in operation. When the bipolar blocking fault occurs, due to the chain cut-off action, the operation of the system unit will change, so its unit adjustment power needs to be recalculated, recorded as The same applies to the moment of inertia J or the inertia constant M0. When the chain cutting occurs, the equivalent inertia constant of the system should be recalculated and recorded as M'=J'ω 0 . The equivalent inertia constant M' of the system of the present invention, the equivalent adjustment coefficient R' of the primary frequency regulation and the time constant T must be calculated according to the unit operation state of the power grid after chain cutting. The primary frequency regulation parameters of the system must also be equivalently calculated according to the spinning reserve capacity of the primary frequency regulation unit of the system and the ratio of various types of units (including hydroelectric generators, non-reheating and reheating turbogenerators, etc.).

当系统的频率升高超过死区时,发电机的原动机调速器将开始作用,改变调节阀门的开度,以使原动机的输入机械功率按照与频率变化的相反方向进行改变。考虑到调节过程的死区和延时,ΔPm与Δω的关系是一个时间函数,其表示关系式为:When the frequency of the system rises beyond the dead zone, the prime mover governor of the generator will start to act and change the opening of the regulating valve so that the input mechanical power of the prime mover changes in the opposite direction to the frequency change. Considering the dead zone and delay of the adjustment process, the relationship between ΔP m and Δω is a time function, and its expression is:

在简化情况下,假设时间延时是经过一个时间常数的环节,即对于阶跃输入T即为所经过的时间常数。In the simplified case, it is assumed that the time delay passes through a time constant link, that is, for a step input T is the elapsed time constant.

综上,直流线路闭锁故障发生后频率动态可用以下微分方程描述:In summary, the frequency dynamics after DC line blocking faults can be described by the following differential equation:

简写为:其中:Abbreviated as: in:

x=Δωx = Δω

M=M′M=M'

应用拉普拉斯变换求解以上微分方程,得到Δω的时域解析式。以上微分方程的拉普拉斯变换为:Applying Laplace transform to solve the above differential equations, the time-domain analytical formula of Δω is obtained. The Laplace transform of the above differential equation is:

可以用图2所示的传递函数框图表示上式。图2中,输入ΔP是阶跃的功率扰动,输出为转速偏差Δω(s),且 The above formula can be represented by the block diagram of the transfer function shown in Figure 2. In Figure 2, the input ΔP is a step power disturbance, the output is the speed deviation Δω(s), and

接着,通过简单的时域仿真,可以获得频率的响应波形,也可以直接计算得到频率偏差的时域表达式Δf(t):Then, through a simple time-domain simulation, the frequency response waveform can be obtained, and the time-domain expression Δf(t) of the frequency deviation can also be directly calculated:

其中, in,

当时间t满足时,Δf(t)有最大值。when time t satisfies , Δf(t) has a maximum value.

通过分析频率偏差峰值与系统高频切机的设定频率,判断该回直流线路是否超过发电机高频切机动作限制,若否(即频率偏差峰值未超过系统高频切机的设定频率),则判定该直流线路不发生高频切机,表明该回直流线路的运行满足安全要求;若是(即频率偏差峰值超过系统高频切机的设定频率),则说明被校验的该回直流线路输电功率过大,连锁切机的量不足,或者一次调频容量不够,应该给出告警信号,提示调度人员采取措施以降低故障发生时的频率峰值。调度人员采取具体的措施可包括:降低该回直流线路的送电功率;增加连锁切机量;增加一次调频旋转备用容量;连锁切机优先切除转动惯量小、容量大或具有反调作用的水电机组等。By analyzing the frequency deviation peak value and the set frequency of the system high-frequency cut-off, judge whether the return DC line exceeds the action limit of the generator high-frequency cut-off, if not (that is, the frequency deviation peak value does not exceed the set frequency of the system high-frequency cut-off ), it is determined that the DC line does not have a high-frequency cut-off, indicating that the operation of the return DC line meets the safety requirements; If the transmission power of the back-to-DC line is too large, the amount of chain cutting machines is insufficient, or the primary frequency modulation capacity is insufficient, an alarm signal should be given to prompt the dispatcher to take measures to reduce the frequency peak when the fault occurs. The specific measures taken by the dispatcher may include: reducing the power transmission power of the return DC line; increasing the amount of chain cut-off; increasing the reserve capacity of a frequency modulation rotation; .

图3为某回直流线路发生双极闭锁后按照本发明的方法计算所得的频率曲线。根据图3可知,频率在2.3秒左右达到峰值50.76Hz,没有超过高频切机动作值50.8Hz,所以该回直流线路的安全稳定方案能够保证系统安全,故采用本发明方法可以快速有效地确定双极闭锁故障后系统的频率峰值,从而校验系统的安全稳定方案是否需要调整。Fig. 3 is a frequency curve calculated according to the method of the present invention after bipolar blocking occurs in a certain DC line. According to Figure 3, it can be seen that the frequency reaches a peak value of 50.76 Hz in about 2.3 seconds, and does not exceed the high-frequency cut-off action value of 50.8 Hz. Therefore, the safety and stability scheme of the return DC line can ensure the safety of the system, so the method of the present invention can be used to quickly and effectively determine The frequency peak value of the system after the bipolar blocking fault, so as to verify whether the security and stability scheme of the system needs to be adjusted.

本发明提出了一种异步电网直流闭锁动态频率监测与安全校核方法,通过对异步联网中的多回直流分别设定闭锁的故障场景并进行校核,为异步电网的运行方式和实时调度提供了校验和决策辅助信息,有效防止了因直流线路闭锁导致送端系统频率超过安全限制而导致的高频切机动作,具有广阔的应用前景。The present invention proposes a dynamic frequency monitoring and safety verification method for DC blocking of an asynchronous power grid. By setting and checking the fault scenarios of blocking for multi-circuit DC in the asynchronous network, it provides the operating mode and real-time scheduling of the asynchronous power grid. The verification and decision-making auxiliary information are obtained, and the high-frequency cut-off action caused by the frequency of the sending end system exceeding the safety limit caused by the blocking of the DC line is effectively prevented, and it has broad application prospects.

以上是对本发明的较佳实施进行了具体说明,但本发明并不限于所述实施例,熟悉本领域的技术人员在不违背本发明精神的前提下还可做作出种种的等同变形或替换,这些等同的变形或替换均包含在本申请权利要求所限定的范围内。The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the described embodiments, and those skilled in the art can also make various equivalent deformations or replacements without violating the spirit of the present invention. These equivalent modifications or replacements are all within the scope defined by the claims of the present application.

Claims (8)

1. A method for monitoring and safety checking of direct current blocking dynamic frequency of an asynchronous power grid is characterized by comprising the following steps: the method comprises the following steps:
acquiring required power grid operation real-time data from an energy management system;
respectively setting each return direct current circuit in the asynchronous power grid to be in a bipolar locking state;
according to the required real-time data of the power grid operation, judging whether high-frequency tripping occurs on each return direct-current line after the bipolar locking under the control action of the frequency regulation and safety and stability scheme of the system by adopting a frequency transient analysis method based on frequency peak estimation;
and (3) carrying out corresponding treatment on each return direct current line according to the judgment result of the high-frequency cutting machine: if the current return direct current line has a high-frequency generator tripping, an alarm signal is sent out to prompt that a safety and stability measure or a system direct current power sending scheme needs to be modified when the current return direct current line has a fault; and otherwise, indicating that the running condition of the current return direct current line meets the safety requirement, and ending the safety check process of the current return direct current line at the moment, wherein the current return direct current line is any return direct current line of each return direct current line.
2. The method for monitoring and checking the direct-current blocking dynamic frequency of the asynchronous power grid according to claim 1, characterized in that: the required real-time data of the power grid operation include but are not limited to primary frequency modulation standby of the system, rated transmission power of each return direct current line, locked chain cutting amount of each return direct current line, current sending power of the system, rotational inertia of the system and load frequency response.
3. The method for monitoring and checking the direct-current blocking dynamic frequency of the asynchronous power grid according to claim 1, characterized in that: the step of setting each return direct-current line in the asynchronous power grid to a bipolar locking state respectively comprises the following steps:
and performing single check, and sequentially setting each return direct-current line of the asynchronous power grid to be in a bipolar blocking state, so that the output power of the return direct-current line after bipolar blocking is reduced to zero, and the return direct-current line after bipolar blocking is subjected to interlocking tripping and direct-current power support which are set by a corresponding safety and stability control scheme.
4. The method for monitoring and checking the direct-current blocking dynamic frequency of the asynchronous power grid according to claim 1, characterized in that: the method comprises the following steps of judging whether high-frequency tripping occurs on each return direct-current line after bipolar locking under the control action of a frequency regulation and safety and stability scheme of a system by adopting a frequency transient analysis method based on frequency peak estimation according to required real-time data of power grid operation, wherein the step comprises the following steps of:
analyzing the response process of the frequency of each return direct-current line under the action of primary frequency modulation, load frequency response and safety and stability measures of a system according to required power grid operation real-time data, and calculating the frequency peak value of each return direct-current line;
and comparing the frequency peak value of each return direct current line with the set frequency of the high-frequency generator tripping of the system, and judging whether the high-frequency generator tripping of each return direct current line after the bipolar locking occurs under the control action of the frequency regulation and safety and stability scheme of the system or not according to the comparison result.
5. The method for monitoring and checking the direct-current blocking dynamic frequency of the asynchronous power grid according to claim 4, wherein the method comprises the following steps: the step of analyzing the response process of the frequency of each return direct current line under the action of system primary frequency modulation, load frequency response and safety and stability measures according to the required real-time data of power grid operation so as to calculate the frequency peak value of each return direct current line comprises the following steps:
the system is equivalent to a unit, a first-order differential equation is adopted to describe the dynamic process of the system frequency deviation according to the required real-time data of the power grid operation, and a time domain expression of the system frequency deviation is solved through time domain simulation, wherein the time domain expression delta f (t) of the system frequency deviation is as follows:
Δ f ( t ) = 50 Δ P D + 1 R [ 1 - 1 + ( a + c b ) 2 c o s ( b t + a r c t a n a + c b ) e - a t ] ,
wherein, m ═ M', t is time, Pm0For normal operation or for instantaneous generator power, Δ P, before bipolar blocking of the DC line occursGFor chain of the amount of cutting machines, P0For normal operation or load power before bipolar blocking of the DC line occurs, omega0For normal operation or for the instantaneous generator speed before bipolar blocking of the DC line occurs, KLFor frequency adjustment coefficient of load, f0To be the frequency of the system,is the system frequency f0K ofLPower of the equation,. DELTA.PDCIs the algebraic sum of the DC power boost and the power that the DC line delivers less power due to bipolar latching,for normal operation or the instant load power before the bipolar locking of the direct current line occurs, R' is the equivalent difference adjustment coefficient of the primary frequency modulation of the system after the action of the linkage cutter occurs,r is the serial number of the unit with spare capacity in the system operation after the action of the chain cutter occurs, n is the total serial number of all the units in the system operation after the action of the chain cutter occurs, (P)m0)rAnd (P)m0)nThe generator sets with the serial numbers r and n respectively operate normally or the instantaneous generator power before the bipolar locking of the direct current circuit occurs,the unit adjusting power of the unit with the sequence number r after the action of the linkage cutter occurs, wherein M is equal to M ', M' is an equivalent inertia constant of a system after the action of the linkage cutter occurs, and T is a time constant;
obtaining the frequency deviation peak value of each return direct current line according to the time domain expression of the system frequency deviation delta f (t), wherein the frequency deviation peak value of each return direct current line meets the requirement of time tThe corresponding frequency offset value.
6. The method for monitoring and checking the direct-current blocking dynamic frequency of the asynchronous power grid according to claim 5, wherein the method comprises the following steps: the method comprises the following steps of equivalently using the system as a unit, describing the dynamic process of the system frequency deviation by adopting a first-order differential equation according to required real-time data of power grid operation, and solving a time domain expression of the system frequency deviation through time domain simulation, wherein the step comprises the following steps of:
the system is equivalent to a unit, a first order differential equation is adopted to describe the dynamic process of the system frequency deviation according to the required real-time data of the power grid operation, and the dynamic process description equation of the system frequency deviation is as follows:
M ′ d d t Δ ω ω 0 + ( 1 + 1 R ′ β ( t ) ) P m 0 - ΔP G ω 0 Δ ω ω 0 + ( K L - 1 ) P L 0 ω 0 · Δ ω ω 0 = P m 0 - ΔP D C ω 0 - P 0 f 0 K L + ΔP D C ω 0 ,
wherein β (t) is step input, Δ ω is rotational speed deviation of system output,
solving a dynamic process description equation of the system frequency deviation by adopting Laplace transformation to obtain a Laplace rotation speed deviation delta omega(s) of the system, wherein an expression of the Laplace rotation speed deviation delta omega(s) of the system is as follows:
Δ ω ( s ) = 1 + T s s [ MTs 2 + ( M + D T ) s + D + 1 R ] · Δ P ,
wherein s is a Laplace operator;
and performing time domain simulation according to the Laplace rotation speed deviation delta omega(s) of the system, and calculating a time domain expression delta f (t) of the frequency deviation of the system.
7. The method for monitoring and checking the direct-current blocking dynamic frequency of the asynchronous power grid according to claim 6, wherein the method comprises the following steps: the method comprises the following steps of comparing the frequency peak value of each return direct current line with the set frequency of the high-frequency generator tripping of the system, and judging whether the high-frequency generator tripping of each return direct current line after the bipolar locking occurs under the control action of the frequency regulation and safety and stability scheme of the system according to the comparison result, wherein the steps are as follows:
if the frequency peak value of each return direct current line exceeds the set frequency of the high-frequency generator tripping of the system, judging that the high-frequency generator tripping of each return direct current line after the bipolar locking occurs under the control action of the frequency regulation and safety and stability scheme of the system; and otherwise, judging that the high-frequency generator tripping of each return direct current line after the bipolar locking cannot occur under the control action of the frequency regulation and safety and stability scheme of the system.
8. The method for monitoring and checking the direct-current blocking dynamic frequency of the asynchronous power grid according to any one of claims 1 to 6, wherein the method comprises the following steps: the operations performed in the process of modifying the safety measure or the system dc power sending scheme when the current return dc line fails include, but are not limited to: reducing the power transmission power of the current return direct current line; the quantity of chain cutters is increased; increasing the primary frequency modulation rotation reserve capacity; the interlocking cutter preferentially cuts off the hydroelectric generating set with small rotational inertia and large capacity or with the function of back adjustment.
CN201611117229.9A 2016-12-07 2016-12-07 A dynamic frequency monitoring and safety checking method for DC blocking of asynchronous power grid Active CN106786714B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201611117229.9A CN106786714B (en) 2016-12-07 2016-12-07 A dynamic frequency monitoring and safety checking method for DC blocking of asynchronous power grid

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201611117229.9A CN106786714B (en) 2016-12-07 2016-12-07 A dynamic frequency monitoring and safety checking method for DC blocking of asynchronous power grid

Publications (2)

Publication Number Publication Date
CN106786714A true CN106786714A (en) 2017-05-31
CN106786714B CN106786714B (en) 2019-09-03

Family

ID=58881282

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201611117229.9A Active CN106786714B (en) 2016-12-07 2016-12-07 A dynamic frequency monitoring and safety checking method for DC blocking of asynchronous power grid

Country Status (1)

Country Link
CN (1) CN106786714B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107800138A (en) * 2017-11-08 2018-03-13 广东电网有限责任公司电力科学研究院 A kind of deviation peak computational method and device based on mains frequency deviation variation rate
CN108400604A (en) * 2018-05-03 2018-08-14 南方电网科学研究院有限责任公司 Control method and device based on asynchronous power grid frequency characteristics
CN110752608A (en) * 2019-10-18 2020-02-04 南方电网科学研究院有限责任公司 Method and device for switching PID (proportion integration differentiation) parameters of speed regulating system of hydroelectric generating set and storage medium

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102412575A (en) * 2011-11-29 2012-04-11 中国电力科学研究院 Simulation evaluation method for configuration scheme of high-frequency cut-off safety automatic device in sending-end power grid
CN102427226A (en) * 2011-11-22 2012-04-25 中国电力科学研究院 Optimization method for safety and stability control measure of multi-direct-current power system
CN104268332A (en) * 2014-09-22 2015-01-07 国家电网公司 High-frequency cutting machine simulation configuration method based on frequency characteristics of regional interconnected power grid
JP2015082954A (en) * 2013-10-24 2015-04-27 富士電機株式会社 Autonomous operation system, autonomous operation controller, and storage battery system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102427226A (en) * 2011-11-22 2012-04-25 中国电力科学研究院 Optimization method for safety and stability control measure of multi-direct-current power system
CN102412575A (en) * 2011-11-29 2012-04-11 中国电力科学研究院 Simulation evaluation method for configuration scheme of high-frequency cut-off safety automatic device in sending-end power grid
JP2015082954A (en) * 2013-10-24 2015-04-27 富士電機株式会社 Autonomous operation system, autonomous operation controller, and storage battery system
CN104268332A (en) * 2014-09-22 2015-01-07 国家电网公司 High-frequency cutting machine simulation configuration method based on frequency characteristics of regional interconnected power grid

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107800138A (en) * 2017-11-08 2018-03-13 广东电网有限责任公司电力科学研究院 A kind of deviation peak computational method and device based on mains frequency deviation variation rate
CN107800138B (en) * 2017-11-08 2020-08-11 广东电网有限责任公司电力科学研究院 Deviation peak value calculation method and device based on power grid frequency deviation change rate
CN108400604A (en) * 2018-05-03 2018-08-14 南方电网科学研究院有限责任公司 Control method and device based on asynchronous power grid frequency characteristics
CN108400604B (en) * 2018-05-03 2024-07-30 南方电网科学研究院有限责任公司 Control method and device based on frequency characteristics of asynchronous power grid
CN110752608A (en) * 2019-10-18 2020-02-04 南方电网科学研究院有限责任公司 Method and device for switching PID (proportion integration differentiation) parameters of speed regulating system of hydroelectric generating set and storage medium
CN110752608B (en) * 2019-10-18 2021-05-14 南方电网科学研究院有限责任公司 Method and device for switching PID (proportion integration differentiation) parameters of speed regulating system of hydroelectric generating set and storage medium

Also Published As

Publication number Publication date
CN106786714B (en) 2019-09-03

Similar Documents

Publication Publication Date Title
CN103440401B (en) Improve the emergent control measure risk quantification appraisal procedure of transmitting capacity of the electric wire netting
CN101969199B (en) Fault Loss Estimation Method for Transient Angle Stability Risk Assessment
CN100403618C (en) Power System Transient Stability Analysis and Control Method
CN102035203B (en) Fast calculation method of tie-line transient state stable limiting transmission power
CN105656024A (en) Electric power system operation standby safety margin online assessment method
CN102412575B (en) Simulation evaluation method for configuration scheme of safe automatic device of transmitting-end power grid high-frequency cutting machine
CN106340907A (en) A method and device for determining a security and stability control strategy of a power system
CN109245044B (en) A Method for Equivalent Sequence Impedance Pilot Protection of Distribution Network
CN106159945B (en) A kind of chain off-grid path chain method for searching of wind-powered electricity generation based under more scene modes
CN104268332A (en) High-frequency cutting machine simulation configuration method based on frequency characteristics of regional interconnected power grid
CN105932705A (en) Emergency control method for high-voltage direct-current continuous commutation failure
CN104578013B (en) A kind of direction protection method of the power distribution network containing DFIG based on power frequency difference
CN113937776B (en) Reactive power calculation method for power grid under disturbance of short circuit fault
CN106875287A (en) A kind of power system switched-mode power supply capacity judging method
CN106786714B (en) A dynamic frequency monitoring and safety checking method for DC blocking of asynchronous power grid
CN104868478B (en) A kind of method of the startup dynamic partition scheme under the power network state of emergency
CN103606922A (en) Approximate judgment method for power angle stability of electric power system based on typical fault set
CN109787266A (en) Method and system for online analysis and decision-making of complex UHV DC faults
CN104113086B (en) A kind of wind-powered electricity generation thermoelectricity cuts machine policy co-ordination optimization method
CN108075478A (en) A kind of transient stability emergency control method
CN102064524A (en) Electrical power system desynchronization and rapid disconnection judging method
CN106099979A (en) A kind of unit under-excitation ability considering that the stabilization of power grids limits analyzes method
CN103762593B (en) A Real-time Quantification Method of Coordinated Control Measures for Safety and Stability of Interregional AC and DC Networking
CN104993466A (en) Cascading failure fast dynamic simulation method suitable for alternating current-direct current power grid
CN115940157A (en) Method, device and equipment for automatically generating load flow scene of stability control strategy checking task

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