WO2013013384A1 - 一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法 - Google Patents
一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法 Download PDFInfo
- Publication number
- WO2013013384A1 WO2013013384A1 PCT/CN2011/077600 CN2011077600W WO2013013384A1 WO 2013013384 A1 WO2013013384 A1 WO 2013013384A1 CN 2011077600 W CN2011077600 W CN 2011077600W WO 2013013384 A1 WO2013013384 A1 WO 2013013384A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- specific frequency
- transmission line
- line
- fault
- direct current
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/085—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution lines, e.g. overhead
Definitions
- the invention belongs to the technical field of power system relay protection, and specifically relates to a full-line quick-action protection method for identifying faults in a region of a high-voltage direct current transmission line by using single-ended electric quantity.
- High-voltage direct current (HVDC) transmission has an increasingly important position in long-distance and high-power transmission because of its large transmission power, low line cost and good control performance. It is used as a large-capacity, long-distance distance in developed countries.
- the main means of power transmission and asynchronous networking has become a hot spot in power construction in China due to "West-to-East Power Transmission, North-South Mutual Supply, and National Networking". Since the introduction of direct current transmission from Gezhouba to Shanghai in 1989, the number of direct current transmission projects in China has been among the best in the world.
- HVDC transmission lines are generally used as the connection line for large-area networking. Its safety and reliability are not only related to the stability of the system, but also directly affect the stable operation of the regional grid or even the entire grid connected to it. Since the DC line is long and the probability of failure is high, improving the operation level of the relay protection of the DC transmission line is of great significance for ensuring the safety and reliability of the DC transmission system. In a sense, the performance of the primary protection of the DC transmission line marks the operating level of the relay protection of the DC system.
- traveling wave protection has the advantage of fast action speed, but in order to effectively utilize the rate of change of voltage and current, traveling wave protection requires extremely high sampling rate. In order to ensure the selectivity of protection in the case of lightning interference, it is forced to reduce the sensitivity of protection and increase the complexity of the protection criteria.
- Research at home and abroad shows that traveling wave protection is not only vulnerable to lightning and interference, but also can not identify high-resistance faults, easy to malfunction, and low reliability of motion.
- the main protection of DC transmission lines put into operation at home and abroad the main protection of the DC transmission line is generally incomplete, there is no universally applicable setting principle, and the setting only depends on the simulation results. Resulting in the DC line
- the electric protection device has high requirements on the sampling rate, and has the problems of poor selectivity, low sensitivity, and low reliability.
- the object of the present invention is to provide a single-ended electric quantity full-line quick-action protection method for faults in a high-voltage direct current transmission line with high sensitivity, high selectivity, fast action speed and high reliability. Thereby providing relay protection for DC transmission lines.
- the present invention provides a single-ended electric quantity full-line quick-motion protection method for identifying faults in a region of a high-voltage direct current transmission line, which utilizes a magnitude realization area of a specific frequency electric quantity on a DC line side of a single-ended converter station. Identification of internal faults and out-of-zone faults.
- the method for determining the fault in the area and the fault outside the area by using the amplitude of the specific frequency electrical quantity on the DC line side of the single-ended converter station is performed according to the following steps:
- Step 1 In the converter station, the electrical quantity signal is obtained from the sensor on the side of the local direct current transmission line; step 2, calculating the sudden change of the current in the unit time according to the current of the pole, and starting the protection when the threshold is greater than the starting threshold;
- Step 3 filtering the electrical quantity signal obtained in step 1 by using a digital filter in the control protection system to obtain a specific frequency electrical quantity;
- Step 4 calculating a magnitude of the specific frequency electrical quantity obtained by the filtering
- Step 5 Compare the amplitude of the specific frequency electrical quantity with the set threshold value to realize the fault in the area and the fault outside the area.
- the set threshold value in the step 5 is set by the electrical quantity that the line side sensor can feel when the metal fault occurs outside the smoothing reactor (away from the DC line side), and the value is determined by the smoothing reactor parameter. , DC filter parameters and line parameters are determined.
- the set threshold value is greater than a magnitude of a specific frequency electrical quantity calculated by step 4 when a most serious fault (such as a metallic ground) occurs outside the smoothing reactor, and the set threshold value is smaller than the direct current transmission line Steps when the slightest fault occurs in the zone (for example, 500 ohm transition resistance is grounded) The magnitude of the specific frequency electrical quantity obtained in step four.
- the electrical quantity signal in the third step is a current signal
- the specific frequency in the third step is a specific frequency point or a specific frequency segment
- the specific frequency point is a tuning frequency point of the DC filter, which is a power frequency. 12, 24, or 36 times the AC frequency;
- the specific frequency segment is 300 Hz or more.
- the specific frequency segment is preferably 300 Hz to 5 kHz.
- the electrical quantity signal in the third step is a voltage signal
- the specific frequency in the third step is a specific frequency segment
- the specific frequency segment is 300 Hz or more.
- the specific frequency segment is preferably 300 Hz to 5 kHz.
- Step 1 The smoothing reactor and the DC filter form a DC filtering link, and the DC filtering link is connected to the DC transmission line at one end with a sensor, the sensor includes a shunt and a voltage divider;
- Step 2 Obtain the minimum input impedance of the DC filter link from the side of the converter station when the fault outside the line is obtained, and obtain the impedance amplitude of the minimum input impedance at different frequencies. In this case, flow through the DC transmission line side. The current of the shunt is the largest;
- Step 3 Obtain the maximum input impedance of the DC filter link from the DC line side when the fault occurs in the line area, and obtain the impedance amplitude of the maximum input impedance at different frequencies. In this case, the current flowing through the DC transmission line side shunt Minimum
- Step 4 Comparing the obtained impedance amplitude of the minimum input impedance with the impedance amplitude of the maximum input impedance, and the impedance amplitude of the minimum input impedance is more than 10 times or more than 100 times of the impedance amplitude of the maximum input impedance.
- the frequency or frequency band is a specific frequency point or a specific frequency band.
- the method for calculating the amplitude of the specific frequency electrical quantity obtained by the filtering in the fourth step includes a Fourier algorithm, a least squares method, an integral method, and other algorithms for obtaining the amplitude of the signal.
- FIG. 1 is a schematic structural diagram of a bipolar direct current transmission system.
- the direct current transmission system is composed of a converter station 1, 2 and a direct current transmission line 3.
- the converter stations 1, 2 are equipped with a converter valve 4.
- the picture / i, ⁇ , / 3 is the fault point, where /; occurs on the DC transmission line 3, called the zone fault point; ⁇ and / occurs on the converter station side, called the out-of-zone fault point.
- Jp and i' jp are the positive DC voltage and DC current of the converter station 1, respectively; jn and i' jn are the DC voltage and DC current of the converter station 1 respectively; M kp and i' kp are the converter stations 2 respectively The positive DC voltage and DC current; , ⁇ are the negative DC voltage and DC current of the converter station 2, respectively.
- the dotted line in Fig. 1 is a filtering section 5 composed of a smoothing reactor and a DC filter.
- the DC transmission system further includes a control protection system 6 disposed on both sides of the DC transmission line 3, and the control protection system 6 can obtain a digital signal of the local pole electric quantity through an A/D converter (not shown) provided therein. And digital signal processing and discrimination to achieve protection.
- the filter section 5 is composed of a smoothing reactor 51 and a DC filter 52.
- the filter section 5 is connected to the DC transmission line 3 via a sensor 8, which comprises a shunt 9 and a voltage divider 10.
- the filter section 5 is connected to the converter valve 4 of the converter station 1 via a splitter 11 and a voltage divider 12.
- ⁇ respectively, is the voltage and current on the converter valve 4 side of the converter station 1
- M 2 and 2 are the voltage and current on the DC transmission line 3 side, respectively. It can be seen from the filtering link 5 of Fig.
- Fig. 3 shows the minimum input impedance Z m of the filter section 5 from the side of the converter valve 4 when the fault occurs outside the zone, and the current felt by the shunt 9 on the DC transmission line side is the largest at the minimum input impedance, Fig. 4
- the DC filter parameters of a DC project are given in Figure 3. The impedance frequency characteristics of the circuit.
- Figure 5 shows the maximum input impedance Z m of the filter section 5 from the side of the DC transmission line 3 when the fault occurs in the line region.
- the current sensed by the shunt 9 on the DC transmission line is the smallest
- Figure 6 shows a DC.
- the filter link 5 composed of the smoothing reactor 51 and the DC filter 52 has a blocking effect on the high frequency, and the higher the frequency, the more obvious the blocking effect is. That is, the component with a higher frequency is difficult to pass from the DC line area to the DC transmission line.
- the impedance frequency characteristic of FIG. 6 that the impedance characteristic of the filter link 5 at both ends of the line has a band pass property in the case of a fault condition in the DC transmission line region, wherein the signals of the three frequencies of 600 Hz, 1200 Hz and 1800 Hz have no blocking effect.
- the DC filter 52 tuning frequency has the least effect on the signal, and the current component of the tuning frequency point will be large, which can reliably determine the faults in the region and outside.
- the energy of the fault signal is mainly concentrated in the low frequency band, and the distribution characteristics of the transmission line parameters and the frequency filtering characteristics increase the filtering and blocking effects of the high frequency signal, the content of the high frequency component is actually small when the transmission line is faulty.
- the conclusion is also confirmed from the recording of DC transmission line faults. Therefore, although the above analysis of signals above 300 Hz has the ability to distinguish between faults in the region and outside, from the perspective of reliability and the relationship between signal processing capability and hardware devices, the fault diagnosis is performed using the low frequency band of frequency components above 300 Hz. It has a more significant technical effect on improving the reliability of operation and reducing the hardware cost.
- This method uses the single-ended electrical quantity as the original information of the criterion. It is only necessary to extract the single-ended specific frequency point of the direct current transmission line or the electrical quantity of the specific frequency band to realize the identification of the regional and external faults. Compared with the protection of double-ended electric quantity, it is not affected by the communication channel, and has high reliability and fast action speed;
- the invention is based on the difference of the impedance characteristics of the DC filter link in the fault zone of the DC transmission line, and proposes a single-end quantity protection method of the DC transmission line, and the structure of the relay protection theory is complete, the selectivity is good, and the sensitivity is high;
- the method of the invention has low requirements on the sampling frequency of the protection device and is easy to implement. It overcomes the problems of high sampling frequency, poor selectivity, low sensitivity and low reliability of the existing DC transmission line traveling wave protection. It can replace the existing traveling wave protection as the main protection of the DC transmission line, especially suitable for single-ended transmission. The electric quantity realizes full-line quick-acting protection of special/ultra-high voltage direct current transmission lines;
- Figure 1 is a schematic structural view of a bipolar direct current transmission system
- FIG. 2 is a circuit diagram of a DC filter component of a smoothing reactor and a DC filter of the bipolar direct current transmission system shown in FIG. 1;
- Figure 3 is the minimum input impedance of the DC filter link from the side of the converter station when the fault occurs outside the line;
- Figure 4 is the frequency characteristic of the minimum input impedance in Figure 3;
- Figure 5 is the maximum input impedance of the DC filter link from the DC line side when the fault occurs in the line region;
- Figure 6 is the frequency characteristic of the maximum input impedance in Figure 5;
- Figure 7 is a simulation diagram of the fault in the current zone (the metal ground of the DC transmission line) according to the specific frequency segment;
- Figure 8 is a simulation diagram of the fault in the current region (point metal grounding of the DC transmission line) according to the specific frequency point current
- Figure 9 is a simulation diagram of a fault in a current frequency determination zone (a point in a DC transmission line is grounded via a 500 ohm transition resistor);
- Figure 10 is a simulation diagram of the fault in the current discrimination area (the point in the DC transmission line is grounded by a 500 ohm transition resistance) according to the specific frequency point;
- Figure 11 is a simulation diagram of the out-of-zone fault (metal grounding on the rectification side) based on the current of a particular frequency segment;
- Figure 12 is a simulation diagram of the out-of-zone fault (metal grounding on the rectification side) based on the current at a specific frequency point;
- Figure 13 is a simulation diagram of the out-of-zone fault (metal grounding on the inverter side) based on the current of a specific frequency band;
- Figure 14 is a simulation diagram of the out-of-zone fault (metal grounding on the inverter side) based on the current at a specific frequency point;
- Figure 15 is a simulation diagram for determining a fault in a zone (point metal ground at a DC transmission line) according to a specific frequency band voltage;
- Figure 16 is a simulation diagram of the fault in the area (voltage passing through the 500 ohm transition resistance of the DC transmission line) according to the voltage in the specific frequency band;
- Figure 17 is a simulation diagram of the fault outside the zone (metal grounding on the rectification side) based on the voltage of the specific frequency band;
- Figure 18 is a simulation diagram of the fault outside the zone (metal grounding on the inverter side) based on the voltage of the specific frequency band.
- the single-ended electric quantity full-line quick-acting protection method for identifying faults in the high-voltage direct current transmission line is mainly used to determine the faults in the area and the faults outside the area by using the amplitude of the specific frequency electric quantity on the DC line side of the single-ended converter station.
- the local current signal is obtained from the sensor on the side of the local direct current transmission line;
- step 3 filtering the local current obtained in step 1 by using a digital filter in the control protection system to obtain a specific frequency current amount;
- Step 2) can be carried out according to the following method: Calculate the current sudden change in unit time according to formula (1), and start the protection when the current threshold is greater than the starting threshold value;
- N is the number of sampling points per unit time, that is, the number of sampling points corresponding to the data window of the starting component, the length of the data window can be 5 ⁇ 10ms ;
- the current mutation / admir,
- the current current sampling value is the normal running current value before the fault; for the reliability coefficient, ⁇ 1, generally 1.2 ⁇ 1.5;
- I set 0.
- U n , / spirit is the rated current of the DC transmission line.
- the specific frequency used in step 4) includes a specific frequency segment and a specific frequency point.
- the specific frequency point is a tuning frequency point of the DC filter, which is 12, 24, or 36 times of the power frequency AC frequency (ie, 600 Hz, 1200 Hz, and 1800 Hz); the specific frequency segment is 300 Hz or more. From the perspective of reliability and the relationship between signal processing capability and hardware devices, the use of low frequency bands in the frequency components above 300 Hz for fault discrimination has a more significant technical effect on improving operational reliability and reducing hardware costs. A frequency range of 300 Hz to 5 kHz is a preferred solution.
- the method for calculating the specific frequency current amplitude obtained by filtering in step 4) includes Fourier algorithm, minimum The two-multiplication method, the integral method, and other algorithms for obtaining the amplitude of the signal.
- the set threshold value described in step 5) is set by the electrical quantity that the line side sensor can feel when a metal fault occurs outside the smoothing reactor (away from the DC line side), and the value is determined by the smoothing reactor parameter, DC. Filter parameters and line parameters are determined.
- the set threshold value is greater than a magnitude of a specific frequency current calculated by the fourth step when a worst fault (for example, a metallic ground) occurs outside the smoothing reactor, and the set threshold is smaller than a maximum occurring in the DC transmission line region.
- the magnitude of the specific frequency current obtained by step four for a minor fault eg 500 ohm transition resistor ground).
- FIG. 7 and FIG. 8 verify the midpoint metal ground fault in the DC transmission line region
- FIG. 9 and FIG. 10 show the 500 ohm excessive resistance ground fault in the midpoint of the DC transmission line region.
- Figure 11 and Figure 12 show the verification results of metallic ground faults outside the DC transmission line and on the rectifier side.
- Figure 13 and Figure 14 show the verification results of metallic ground faults outside the DC transmission line and on the inverter side. .
- Fig. 7, Fig. 9, Fig. 11, and Fig. 13 are the results of discrimination based on the current of a specific frequency range of 500 Hz to 4.8 kHz.
- the starting threshold is 0.11 ⁇ , and the threshold value of the signal in the specific frequency band is set to 0.005 In.
- Figures 8, 10, 12 and 14 are the results of the discrimination based on the current at a specific frequency point of 600 Hz.
- the starting threshold is 0.11 ⁇ , and the threshold of the specific frequency signal is set to 0.002 In.
- the method of the present invention can be significantly shown to have high sensitivity, good selectivity, fast action speed, and high reliability for regional and out-of-area fault discrimination. This provides reliable relay protection for DC transmission lines.
- the single-ended electric quantity full-line quick-acting protection method for identifying faults in the high-voltage direct-current transmission line area mainly utilizes the amplitude of the specific frequency electric quantity on the DC line side of the single-ended converter station to realize the fault in the area and the fault outside the area.
- step 3 filtering the local voltage signal obtained in step 1 by using a digital filter in the control protection system to obtain a specific frequency voltage amount;
- step 2) The specific steps used in step 2) are the same as those in the first embodiment. No longer repeat.
- a voltage amount starting method can also be employed. For example, starting with a voltage amount, this embodiment can be realized only by using a voltage.
- the specific frequency used is a specific frequency segment.
- the specific frequency segment is 300 Hz or more. From the perspective of reliability and the relationship between signal processing capability and hardware devices, the use of low-frequency bands in frequency components above 300 Hz for fault identification has a more significant technical effect on improving operational reliability and reducing hardware costs. A frequency range of 300 Hz to 5 kHz is a preferred solution.
- the method for calculating the specific frequency voltage amplitude obtained by filtering in step 4) includes Fourier algorithm, least squares method, integral method, and other algorithms for obtaining signal amplitude.
- the set threshold value described in step 5 is set by the electrical quantity that the line side sensor can feel when a metal fault occurs outside the smoothing reactor (away from the DC line side), and the value is determined by the smoothing reactor parameter, DC. Filter parameters and line parameters are determined.
- the set threshold value is greater than a magnitude of a specific frequency voltage calculated by the fourth step when the most severe fault occurs outside the smoothing reactor (for example, metallic grounding), and the set threshold value is smaller than the most generated in the DC transmission line region.
- the magnitude of the specific frequency voltage obtained from step four for a minor fault eg 500 ohm transition resistor ground).
- FIG. 15 to FIG. 18 different regional and out-of-zone faults are simulated and verified.
- FIG. 15 verifies the metal ground fault in the mid-point of the DC transmission line
- FIG. 16 The midpoint of the DC transmission line is verified by a 500 ohm over-resistance ground fault
- Figure 17 is the verification result of the metallic ground fault occurring outside the DC transmission line and on the rectifier side
- Figure 18 is the outside of the DC transmission line and the inverter
- 15 to 18 are the results of discrimination based on a current of a frequency band of 500 Hz to 4.8 kHz.
- the starting threshold is O.lln, and the threshold of the specific frequency band signal is set to 0.005 Un, where Un is the rated voltage of the DC transmission line.
- the method of the present invention has high sensitivity, good selectivity, fast action speed, and high reliability for regional and out-of-area fault discrimination. This provides reliable relay protection for DC transmission lines.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法，其利用单端换流站直流线路侧电气量的特定频率分量的幅值实现区内、外故障的判别。该保护方法仅需要采用单端电气量，对采样频率要求不高，算法简单，在工程上易于实现。此外，该保护方法动作速度快，选择性好，可靠性高，理论完备易于整定。
Description
一种识别高压直流输电线路区内、 外故障的
单端电气量全线速动保护方法
技术领域
本发明属于电力系统继电保护技术领域， 具体来说， 是一种利用单端电气 量识别高压直流输电线路区内、 外故障的全线速动保护方法。
背景技术
高压直流 (HVDC)输电以其传输功率大， 线路造价低，控制性能好等优点， 在远距离、大功率输电中占有越来越重要的地位， 世界发达国家都把它作为大 容量、远距离送电和异步联网的主要手段，在我国也因"西电东送，南北互供， 全国联网"而成为电力建设的热点。 自 1989年葛洲坝至上海采用直流输电以 来， 我国直流输电工程数量在世界上已名列前茅。
高压直流输电线路一般作为大区域联网的联络线，它的安全性和可靠性不 仅关系到本系统的稳定性，而且将直接影响与其连接的区域电网甚至整个电网 的稳定运行。 由于直流线路长， 发生故障的概率高， 因此提高直流输电线路继 电保护的运行水平对保证直流输电系统的安全性与可靠性具有重要意义。而从 某种意义上来讲，直流输电线路主保护的性能标志了直流系统继电保护的运行 水平。
目前，运行中的直流线路多以行波保护作为主保护。行波保护具有动作速 度快的优点， 但为了有效利用电压、 电流的变化率， 行波保护对采样率要求极 高。 为了保证雷电干扰情况下保护的选择性， 被迫降低了保护的灵敏度， 也增 加了保护判据的复杂性。 国内外研究表明：行波保护不但易受雷电和干扰的影 口向， 而且不能够识别高阻故障， 易误动， 动作的可靠性低。 综上所述， 国内外 投运的直流输电工程， 其直流输电线路的主保护普遍存在着理论不完备、没有 普遍适用的整定原则、整定仅依赖于仿真结果等问题。从而导致了直流线路继
电保护装置对采样率要求高， 且存在着选择性差、灵敏度低、可靠性不高的问 题。
发明内容
本发明的目的在于提供一种灵敏度高、选择性好、 动作速度快、 可靠性高 的高压直流输电线路区内、外故障的单端电气量全线速动保护方法。从而为直 流输电线路提供继电保护。
为达到上述目的， 本发明提供一种识别高压直流输电线路区内、外故障的 单端电气量全线速动保护方法，其利用单端换流站直流线路侧特定频率电气量 的幅值实现区内故障、 区外故障的判别。
进一步的，所述的利用单端换流站直流线路侧特定频率电气量的幅值实现 区内故障、 区外故障的判别按照以下步骤进行：
步骤一，在换流站中，从本极直流输电线路侧的传感器中获得电气量信号； 步骤二， 根据本极电流计算单位时间内的电流突变， 大于起动门槛值时起 动该保护；
步骤三，利用控制保护系统中的数字滤波器对从步骤一中获得的电气量信 号进行滤波， 获得特定频率电气量；
步骤四， 计算滤波得到的特定频率电气量的幅值；
步骤五，比较特定频率电气量的幅值与设定门槛值的大小，实现区内故障、 区外故障判别。
进一步的，所述步骤五中的设定门槛值由平波电抗器外侧（远离直流线路 侧）发生金属性故障时线路侧传感器所能感受的电气量进行整定， 其值由平波 电抗器参数、 直流滤波器参数以及线路参数确定。
进一步的，所述设定门槛值大于平波电抗器外侧发生最严重故障（例如金 属性接地）时由步骤四计算得到的特定频率电气量的幅值， 并且该设定门槛值 小于直流输电线路区内发生最轻微故障（例如 500欧姆过渡电阻接地）时由步
骤四得到的特定频率电气量的幅值。
进一步的，所述步骤三中的电气量信号为电流信号，所述步骤三中的特定 频率为特定频率点或特定频率段， 所述特定频率点为直流滤波器的调谐频率 点， 为工频交流频率的 12、 24、 或 36倍； 所述特定频率段为 300Hz以上。 其 中所述特定频率段优选为 300Hz~5kHz。
进一步的，所述步骤三中的电气量信号为电压信号，所述步骤三中的特定 频率为特定频率段， 所述特定频率段为 300Hz 以上。 其中所述特定频率段优 选为 300Hz~5kHz。
进一步的， 所述特定频率按照以下方法获得：
步骤一： 以平波电抗器和直流滤波器构成直流滤波环节， 该直流滤波环节 与直流输电线路连接的一端设有传感器， 该传感器包括分流器和分压器；
步骤二：获得线路区外故障时从换流站侧看所述直流滤波环节的最小输入 阻抗， 并获得该最小输入阻抗在不同频率下的阻抗幅值，在此情况下流过直流 输电线路侧的分流器的电流最大；
步骤三：获得线路区内故障时从直流线路侧看直流滤波环节的最大输入阻 抗， 并获得该最大输入阻抗在不同频率下的阻抗幅值， 在该情况下流过直流输 电线路侧分流器的电流最小；
步骤四：将获得的上述最小输入阻抗的阻抗幅值与最大输入阻抗的阻抗幅 值进行对比， 最小输入阻抗的阻抗幅值比最大输入阻抗的阻抗幅值大 10倍以 上或 100倍以上所对应的频点或频带即为特定频率点或特定频率带。
进一步的，所述步骤四中计算滤波得到的特定频率电气量幅值的方法包括 傅氏算法、 最小二乘法、 积分法、 以及其它求取信号幅值的算法。
以下是本发明的原理：
请参照图 1， 图 1为双极直流输电系统的结构简图。 直流输电系统由换流 站 1、 2和直流输电线路 3构成。换流站 1、 2都装设有换流阀 4。 图中/ i、 Λ、
/3为故障点， 其中 /;发生在直流输电线路 3上， 称为区内故障点； Λ和/发 生换流站侧， 称为区外故障点。 jp、 i'jp分别是换流站 1的正极直流电压和直 流电流； jn、 i'jn分别是换流站 1的负极直流电压和直流电流； Mkp、 i'kp分别 是换流站 2的正极直流电压和直流电流； 、 ^分别是换流站 2的负极直 流电压和直流电流。图 1中虚线部分为平波电抗器和直流滤波器组成的滤波环 节 5。 该直流输电系统还包括设置在直流输电线路 3两侧的控制保护系统 6， 该控制保护系统 6通过其中设有的 A/D转换器 （未图示） 可获得本端极电气 量的数字信号， 并进行数字信号的处理、 判别， 实现保护功能。
图 2是滤波环节 5的电路图。 滤波环节 5由平波电抗器 51和直流滤波器 52构成。 滤波环节 5与直流输电线路 3通过传感器 8连接， 该传感器 8包括 分流器 9和分压器 10。 滤波环节 5与换流站 1的换流阀 4通过分流器 11和分 压器 12连接。图中 ^、 分别是换流站 1换流阀 4侧的电压和电流， M2、 2分 别是直流输电线路 3侧的电压和电流。从图 2的滤波环节 5可以看出： 当直流 输电线路 3区外发生故障时， 由于平波电抗器 51的阻滞作用， 使得直流输电 线路 3侧的分流器 9感受到的较高频电流分量很小；当直流输电线路 3区内发 生故障时， 由于没有平波电抗器 51的阻挡作用， 直流输电线路 3侧的分流器 9感受到的较高频电流分量很大， 该特性可以用来区分直流输电线路区内、 外 故障， 且具有较高的灵敏度和选择性。
为了充分利用滤波环节 5在直流输电线路 3区内、区外故障时所表现出的 这种差异性， 构造具有绝对选择性的继电保护原理， 需要分析在哪些频带中， 直流输电线路 3区外故障时分流器 9所感受到的最大电流还远远小于直流输电 线路 3区内故障的最小短路电流。为此图 3给出了发生区外故障时从换流阀 4 侧看滤波环节 5的最小输入阻抗 Zm， 在最小输入阻抗时直流输电线路侧的分 流器 9感受到的电流最大， 图 4给出了某直流工程的直流滤波器参数下图 3
电路的阻抗频率特性。图 5给出了线路区内故障时从直流输电线路 3侧看滤波 环节 5的最大输入阻抗 Zm， 该情况下直流输电线路侧分流器 9感受到的电流 最小， 图 6给出了某直流工程的直流滤波器参数下图 5电路的阻抗频率特性。
从图 4的阻抗频率特性可知， 在直流线路区外故障时， 由平波电抗器 51 与直流滤波器 52构成的滤波环节 5对高频具有阻滞作用， 频率越高阻滞效果 越明显， 即频率较高的分量难以从直流线路区外传到直流输电线路上。 由图 6 的阻抗频率特性可知，在直流输电线路区内故障情况时， 线路两端的滤波环节 5的阻抗特性具有带通性质， 其中对 600Hz、 1200Hz和 1800Hz三个频率的信 号没有阻滞作用， 也就是说这三个频率下的电流将不会受到阻滞， 直流输电线 路侧的分流器 9感受到的这三个频率分量的幅值会较大。与图 6对比可知， 图 4中的阻抗特性在以上三个频点所表现的阻抗远大于 lkQ。 也就是说， 在区外 故障情况下， 直流线路侧在以上三个频率的电流分量远小于区内故障情况。 因 此， 可以根据以上三个频率分量的含量来区分直流输电线路区内、 外故障。
从图 4和图 6还可以看出， 对于 300Hz以上频率信号， 图 4的阻滞能力 则比图 6高出 100倍以上。
考虑到直流输电线路 3区内故障时， 直流滤波器 52调谐频率对信号的阻 滞作用最小， 调谐频率点的电流分量将较大， 可以可靠的进行区内、外故障的 判别。考虑到故障信号的能量主要集中在低频带， 以及输电线路参数的分布特 性和频变特性对高频信号的滤波和阻滞作用增加等因素，输电线路故障时高频 分量含量其实较小，该结论从直流输电线路故障的录波中也得到了证实。因此， 虽然前面分析了 300Hz 以上的信号都具有区内、 外故障的区分能力， 但从可 靠性的角度和信号处理能力与硬件装置关系的角度考虑， 利用 300Hz 以上频 率分量中低频带进行故障判别，对提高动作可靠性和降低硬件成本有更为显著 的技术效果。
本发明具有以下有益效果：
1、 本方法采用单端电气量作为判据的原始信息， 仅需提取直流输电线路 的单端特定频率点或特定频率带的电气量即可实现区内、外故障的判别。与利 用双端电气量的保护相比， 不受通信通道的影响可靠性高、 动作速度快；
2、 本发明是基于直流输电线路区内、 外故障时直流滤波环节阻抗特性差 异，提出直流输电线路单端量保护方法，构造的继电保护理论完备、选择性好、 灵敏度高；
3、 与现有方法相比， 本发明方法对保护装置的采样频率要求低、 易于实 现。 克服了现有直流输电线路行波保护对采样频率要求高、选择性差、 灵敏度 低、可靠性不高等问题，可以取代现有的行波保护作为直流输电线路的主保护， 尤其适合于利用单端电气量实现特 /超高压直流输电线路的全线速动保护；
4、 利用与平波电抗器和直流滤波器有关的特征频率信号进行故障识别， 由于这些信号频率相对较低， 且具有幅值高、 能量大的特点， 因此利用该频率 信号的继电保护将具有对采样率低、 可靠性高的特点。
附图说明
图 1为双极直流输电系统结构示意图；
图 2是图 1所示的双极直流输电系统的平波电抗器和直流滤波器构成的直 流滤波环节的电路图；
图 3是线路区外故障时从换流站侧看直流滤波环节的最小输入阻抗； 图 4是图 3中的最小输入阻抗的频率特性；
图 5是线路区内故障时从直流线路侧看直流滤波环节的最大输入阻抗； 图 6是图 5中的最大输入阻抗的频率特性；
图 7 是根据特定频率段电流判别区内故障 （直流输电线路中点金属性接 地） 的仿真图；
图 8 是根据特定频率点电流判别区内故障 （直流输电线路中点金属性接 地） 的仿真图；
图 9是根据特定频率段电流判别区内故障（直流输电线路中点经 500欧姆 过渡电阻接地） 的仿真图；
图 10是根据特定频率点电流判别区内故障 （直流输电线路中点经 500欧 姆过渡电阻接地） 的仿真图；
图 11是根据特定频率段电流判别区外故障 （整流侧发生金属性接地） 的 仿真图；
图 12是根据特定频率点电流判别区外故障 （整流侧发生金属性接地） 的 仿真图；
图 13是根据特定频率段电流判别区外故障 （逆变侧发生金属性接地） 的 仿真图；
图 14是根据特定频率点电流判别区外故障 （逆变侧发生金属性接地） 的 仿真图；
图 15是根据特定频率段电压判别区内故障 （直流输电线路中点金属性接 地） 的仿真图；
图 16是根据特定频率段电压判别区内故障 （直流输电线路中点经 500欧 姆过渡电阻接地） 的仿真图；
图 17是根据特定频率段电压判别区外故障 （整流侧发生金属性接地） 的 仿真图；
图 18是根据特定频率段电压判别区外故障 （逆变侧发生金属性接地） 的 仿真图。
具体实施方式
实施例 1:
识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法， 主 要利用单端换流站直流线路侧特定频率电气量的幅值实现区内故障、区外故障 的判别。
按照以下步骤进行：
1 ) 在换流站中， 从本极直流输电线路侧的传感器中获得本极电流信号；
2 ) 根据本极电流计算单位时间内的电流突变， 大于起动门槛值时起动保 护；
3 ) 利用控制保护系统中的数字滤波器对从步骤一中获得的本极电流进行 滤波， 获得特定频率电流量；
4) 计算滤波得到的特定频率电流的幅值；
5 ) 比较特定频率电流的幅值与设定门槛值的大小， 实现直流输电线路区 内故障、 区外故障判别。
其中步骤 2) 可按照以下方法进行： 根据公式 （1 ) 用本端电流计算单位时间内的电流突变， 大于起动门槛值 时起动该保护；
N
∑^i > KNIset ( 1 )
m=l
其中： m=l， 2, ...， N; N为单位时间内采样点数， 也就是起动元件数据 窗所对应的采样点数， 数据窗长度可取 5~10ms; 电流突变 = /„， 为本 极当前电流采样值， 为本极故障前正常运行电流值； 为可靠系数， ^≥1， 一般可取 1.2~1.5； Iset = 0. Un , /„为直流输电线路的额定电流。 步骤 4)所采用的特定频率包括特定频率段和特定频率点。 所述特定频率 点为直流滤波器的调谐频率点，为工频交流频率的 12、24、或 36倍（即 600Hz、 1200Hz和 1800Hz); 所述特定频率段为 300Hz以上。 若从可靠性的角度和信号处理能力与硬件装置关系的角度考虑， 利用 300Hz以上频率分量中低频带进行故障判别，对提高动作可靠性和降低硬件成 本有更为显著的技术效果， 则采用特定频率段 300Hz~5kHz为优选方案。
步骤 4) 中计算滤波得到的特定频率电流幅值的方法包括傅氏算法、 最小
二乘法、 积分法、 以及其它求取信号幅值的算法。
步骤 5 ) 中所述的设定门槛值由平波电抗器外侧 （远离直流线路侧） 发生 金属性故障时线路侧传感器所能感受的电气量进行整定，其值由平波电抗器参 数、直流滤波器参数以及线路参数确定。所述设定门槛值大于平波电抗器外侧 发生最严重故障（例如金属性接地）时由步骤四计算得到的特定频率电流的幅 值， 并且该设定门槛值小于直流输电线路区内发生最轻微故障（例如 500欧姆 过渡电阻接地） 时由步骤四得到的特定频率电流的幅值。
本实施例中对不同的区内、 区外故障进行了仿真验证。 请参照图 7 至图 14， 其中图 7和图 8对直流输电线路区内中点金属性接地故障进行了验证； 图 9和图 10对直流输电线路区内中点经 500欧姆过度电阻接地故障进行了验证； 图 11和图 12是直流输电线路区外、 整流侧发生金属性接地故障的验证结果； 图 13和图 14是直流输电线路区外、 逆变侧发生金属性接地故障的验证结果。 其中图 7、 图 9、 图 11、 图 13均是是根据特定频率段为 500Hz-4.8KHz的电流 所作出的判别结果。 其中起动门槛值为 0.11η, 特定频段信号的门槛值设定为 0.005 In。 图 8、 图 10、 图 12及图 14均是根据特定频率点 600Hz的电流所作 出的判别结果。 其中起动门槛值为 0.11η, 特定频点信号的门槛值设定为 0.002 In。
根据图 7至图 14的验证结果， 可以显著地显示本发明的方法对于区内、 区外故障判别的灵敏度高、 选择性好、 动作速度快、 可靠性高。 从而为直流输 电线路提供可靠的继电保护。
实施例 2:
识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法， 主 要利用单端换流站直流线路侧特定频率电气量的幅值实现区内故障、区外故障 的判别。
按照以下步骤进行：
2 ) 根据本极电流信号计算单位时间内的电流突变， 大于起动门槛值时起 动保护；
3 ) 利用控制保护系统中的数字滤波器对从步骤一中获得的本极电压信号 进行滤波， 获得特定频率电压量；
4) 计算滤波得到的特定频率电压量的幅值；
5 ) 比较特定频率电压量的幅值与设定门槛值的大小， 实现区内故障、 区 外故障判别。
其中步骤 2)采用的具体步骤与实施例 1中的一致。 不再重复。 在此也可 以采用电压量起动方法， 如采用电压量起动， 本实施例仅用电压即可实现。
步骤 4)所采用的特定频率为特定频率段。所述特定频率段为 300Hz以上。 若从可靠性的角度和信号处理能力与硬件装置关系的角度考虑， 利用 300Hz 以上频率分量中低频带进行故障判别，对提高动作可靠性和降低硬件成本有更 为显著的技术效果， 则采用特定频率段为 300Hz~5kHz为优选方案。
步骤 4) 中计算滤波得到的特定频率电压幅值的方法包括傅氏算法、 最小 二乘法、 积分法、 以及其它求取信号幅值的算法。
步骤 5 ) 中所述的设定门槛值由平波电抗器外侧 （远离直流线路侧） 发生 金属性故障时线路侧传感器所能感受的电气量进行整定，其值由平波电抗器参 数、直流滤波器参数以及线路参数确定。所述设定门槛值大于平波电抗器外侧 发生最严重故障（例如金属性接地）时由步骤四计算得到的特定频率电压的幅 值， 并且该设定门槛值小于直流输电线路区内发生最轻微故障（例如 500欧姆 过渡电阻接地） 时由步骤四得到的特定频率电压的幅值。
本实施例中对不同的区内、 区外故障进行了仿真验证。 请参照图 15至图 18， 其中图 15 对直流输电线路区内中点金属性接地故障进行了验证； 图 16
对直流输电线路区内中点经 500欧姆过度电阻接地故障进行了验证； 图 17是 直流输电线路区外、 整流侧发生金属性接地故障的验证结果； 图 18是直流输 电线路区外、逆变侧发生金属性接地故障的验证结果。其中图 15至图 18均是 根据特定频率段为 500Hz-4.8kHz的电流所作出的判别结果。 其中起动门槛值 为 O.lln,特定频段信号的门槛值设定为 0.005 Un,其中 Un为直流输电线路的 额定电压。
根据图 15至图 18的验证结果， 可以显著地显示本发明的方法对于区内、 区外故障判别的灵敏度高、 选择性好、 动作速度快、 可靠性高。 从而为直流输 电线路提供可靠的继电保护。
以上内容是结合具体的优选实施方式对本发明所作的进一步详细说明，不 能认定本发明的具体实施方式仅限于此，对于本发明所属技术领域的普通技术 人员来说，在不脱离本发明构思的前提下，还可以做出若干简单的推演或替换， 都应当视为属于本发明由所提交的权利要求书确定专利保护范围。
Claims
1、 一种识别高压直流输电线路区内、 外故障的单端电气量全线 速动保护方法， 其特征在于： 利用单端换流站直流线路侧特定频率电 气量的幅值实现区内故障、 区外故障的判别。
2、 根据权利要求 1所述的识别高压直流输电线路区内、 外故障 的单端电气量全线速动保护方法， 其特征在于： 所述的利用单端换流 站直流线路侧特定频率电气量的幅值实现区内故障、区外故障的判别 按照以下步骤进行：
步骤一， 在换流站中， 从本极直流输电线路侧的传感器中获得电 步骤二， 根据本极电流计算单位时间内的电流突变， 大于起动门 槛值时起动该保护；
步骤三，利用控制保护系统中的数字滤波器对从步骤一中获得的 电气量信号进行滤波， 获得特定频率电气量；
步骤四， 计算滤波得到的特定频率电气量的幅值；
步骤五， 比较特定频率电气量的幅值与设定门槛值的大小， 实现 区内故障、 区外故障判别。
3、 根据权利要求 2所述的识别高压直流输电线路区内、 外故障 的单端电气量全线速动检测方法， 其特征在于： 所述换流站包括换流 阀及直流滤波环节， 该直流滤波环节设有平波电抗器和直流滤波器， 所述步骤五中的设定门槛值由所述平波电抗器外侧发生金属性故障 时直流输电线路侧的传感器所能感受的电气量进行整定，其值由平波 电抗器参数、 直流滤波器参数以及线路参数确定。
4、 根据权利要求 3所述的识别高压直流输电线路区内、 外故障 的单端电气量全线速动检测方法， 其特征在于： 所述设定门槛值大于
权利要求书 平波电抗器外侧发生最严重故障时由步骤四计算得到的特定频率电 气量的幅值，并且该设定门槛值小于直流输电线路区内发生最轻微故 障时由步骤四得到的特定频率电气量的幅值。
5、 根据权利要求 2所述的识别高压直流输电线路区内、 外故障 的单端电气量全线速动检测方法， 其特征在于： 所述步骤三中的电气 量信号为电流信号，所述步骤三中的特定频率为特定频率点或特定频 率段， 所述特定频率点为直流滤波器的调谐频率点， 为工频交流频率 的 12、 24、 或 36倍； 所述特定频率段为 300Hz以上。
6、 根据权利要求 5所述的识别高压直流输电线路区内、 外故障 的单端电气量全线速动检测方法， 其特征在于： 所述特定频率段为 300Hz~5kHz。
7、 根据权利要求 2所述的识别高压直流输电线路区内、 外故障 的单端电气量全线速动检测方法， 其特征在于： 所述步骤三中的电气 量信号为电压信号， 所述步骤三中的特定频率为特定频率段， 所述特 定频率段为 300Hz以上。
8、 根据权利要求 7所述的识别高压直流输电线路区内、 外故障 的单端电气量全线速动检测方法， 其特征在于： 所述特定频率段为 300Hz~5kHz。
9、 根据权利要求 2、 3、 4、 5、 6、 7或 8所述的识别高压直流输 电线路区内、 外故障的单端电气量全线速动保护方法， 其特征在于： 所述特定频率按照以下方法获得：
步骤一： 以平波电抗器和直流滤波器构成直流滤波环节， 该直流 滤波环节与直流输电线路连接的一端设有传感器，该传感器包括分流 器和分压器；
权利要求书 步骤二：获得线路区外故障时从换流站侧看所述直流滤波环节的 最小输入阻抗， 并获得该最小输入阻抗在不同频率下的阻抗幅值， 在 此情况下流过直流输电线路侧的分流器的电流最大；
步骤三：获得线路区内故障时从直流线路侧看直流滤波环节的最 大输入阻抗， 并获得该最大输入阻抗在不同频率下的阻抗幅值， 在该 情况下流过直流输电线路侧分流器的电流最小；
步骤四：将获得的上述最小输入阻抗的阻抗幅值与最大输入阻抗 的阻抗幅值进行对比，最小输入阻抗的阻抗幅值比最大输入阻抗的阻 抗幅值大 10倍以上或 100倍以上所对应的频点或频带即为特定频率 点或特定频率带。
10、根据权利要求 2所述的识别高压直流输电线路区内、外故障 的单端电气量全线速动保护方法， 其特征在于： 所述步骤四中计算滤 波得到的特定频率电气量幅值的方法包括傅氏算法、最小二乘法、积 分法、 以及其它求取信号幅值的算法。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2011/077600 WO2013013384A1 (zh) | 2011-07-26 | 2011-07-26 | 一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2011/077600 WO2013013384A1 (zh) | 2011-07-26 | 2011-07-26 | 一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2013013384A1 true WO2013013384A1 (zh) | 2013-01-31 |
Family
ID=47600460
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/CN2011/077600 WO2013013384A1 (zh) | 2011-07-26 | 2011-07-26 | 一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法 |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2013013384A1 (zh) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103956713A (zh) * | 2014-04-01 | 2014-07-30 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | 一种考虑电磁耦合关系的直流输电线路保护配置整定方法 |
| CN104820158A (zh) * | 2015-04-30 | 2015-08-05 | 国家电网公司 | 一种柔性直流输电系统直流断线故障判断方法 |
| CN107872050A (zh) * | 2017-10-30 | 2018-04-03 | 中国电力科学研究院有限公司 | 一种基于电流频谱的直流输电线路保护方法和装置 |
| CN108321776A (zh) * | 2018-02-06 | 2018-07-24 | 上海交通大学 | 基于特定频段电流的特高压直流线路保护方法 |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5796257A (en) * | 1992-08-27 | 1998-08-18 | The University Of Bath | Detecting faults in power lines |
| CN101697411A (zh) * | 2009-10-29 | 2010-04-21 | 华南理工大学 | 直流输电线路的暂态能量保护方法 |
| CN101777759A (zh) * | 2010-03-23 | 2010-07-14 | 西安交通大学 | 一种基于单端暂态信号的超高速直流线路整套保护装置及保护方法 |
| CN102255293A (zh) * | 2011-07-26 | 2011-11-23 | 西安交通大学 | 一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法 |
-
2011
- 2011-07-26 WO PCT/CN2011/077600 patent/WO2013013384A1/zh active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5796257A (en) * | 1992-08-27 | 1998-08-18 | The University Of Bath | Detecting faults in power lines |
| CN101697411A (zh) * | 2009-10-29 | 2010-04-21 | 华南理工大学 | 直流输电线路的暂态能量保护方法 |
| CN101777759A (zh) * | 2010-03-23 | 2010-07-14 | 西安交通大学 | 一种基于单端暂态信号的超高速直流线路整套保护装置及保护方法 |
| CN102255293A (zh) * | 2011-07-26 | 2011-11-23 | 西安交通大学 | 一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法 |
Non-Patent Citations (1)
| Title |
|---|
| GAO, SHUPING ET AL.: "A New Pilot Protection Principle for HVDC Transmission Lines Based on Current Fault Component", AUTOMATION OF ELECTRIC POWER SYSTEMS., vol. 35, no. 5, 10 March 2011 (2011-03-10), pages 52 - 56, 86 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103956713A (zh) * | 2014-04-01 | 2014-07-30 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | 一种考虑电磁耦合关系的直流输电线路保护配置整定方法 |
| CN103956713B (zh) * | 2014-04-01 | 2017-01-04 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | 一种考虑电磁耦合关系的直流输电线路保护配置整定方法 |
| CN104820158A (zh) * | 2015-04-30 | 2015-08-05 | 国家电网公司 | 一种柔性直流输电系统直流断线故障判断方法 |
| CN107872050A (zh) * | 2017-10-30 | 2018-04-03 | 中国电力科学研究院有限公司 | 一种基于电流频谱的直流输电线路保护方法和装置 |
| CN107872050B (zh) * | 2017-10-30 | 2022-03-18 | 中国电力科学研究院有限公司 | 一种基于电流频谱的直流输电线路保护方法和装置 |
| CN108321776A (zh) * | 2018-02-06 | 2018-07-24 | 上海交通大学 | 基于特定频段电流的特高压直流线路保护方法 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102255293B (zh) | 一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法 | |
| WO2013086944A1 (zh) | 一种利用直流滤波器电流的高压直流输电全线速度保护方法 | |
| CN105140897B (zh) | 一种适用于小电阻接地系统单相接地故障的保护方法 | |
| CN104614608B (zh) | 一种低压并联电弧故障检测装置及方法 | |
| CN103323674B (zh) | 光伏并网逆变器的对地绝缘阻抗的实时检测电路和检测方法 | |
| CN103219712B (zh) | 基于固有频率的输电线路单相故障性质识别方法 | |
| CN113300336B (zh) | 一种新型高压直流输电线路保护方法 | |
| CN108599114A (zh) | 一种高压交直流混联系统交流线路暂态方向保护方法 | |
| CN114243659B (zh) | 基于调谐频率下测量波阻抗的高压直流输电线路纵联保护方法 | |
| CN109713706B (zh) | 交直流混联系统逆变侧交流线路单端超高速保护方法 | |
| WO2013013384A1 (zh) | 一种识别高压直流输电线路区内、外故障的单端电气量全线速动保护方法 | |
| CN111641196A (zh) | 一种基于支路电流特性的高压直流线路纵联保护方法 | |
| CN105891678B (zh) | 基于频带测量阻抗的特高压直流线路故障判别方法 | |
| Ying et al. | Travelling wave‐based pilot direction comparison protection for HVDC line | |
| CN110579685B (zh) | 一种特高压直流系统接地极线路保护方法及装置 | |
| CN103592569B (zh) | 一种基于高频量衰减特性的特高压直流输电线路故障测距方法 | |
| Hou et al. | Single-end fault identification scheme for multi-terminal DC grid based on amplitude similarity of injection signal | |
| CN104090211B (zh) | 一种配电线路高阻接地故障的在线检测方法 | |
| CN112083280B (zh) | 一种识别混合多端直流输电系统故障区间的方法 | |
| CN105552835B (zh) | 一种直流线路50Hz谐波保护防误动的方法 | |
| CN108321776B (zh) | 基于特定频段电流的特高压直流线路保护方法 | |
| CN108551160B (zh) | 一种基于极波能量的多端直流输电系统故障区段的判断方法及系统 | |
| Xiaotong et al. | A novel high-speed transient-based phase selector for AC transmission line connected to LCC-HVDC inverter station | |
| CN103176083B (zh) | 相间干扰对金属氧化物避雷器带电测试影响情况的诊断方法 | |
| CN115800195A (zh) | 一种并联电抗器匝间保护方法 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11870086 Country of ref document: EP Kind code of ref document: A1 |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 11870086 Country of ref document: EP Kind code of ref document: A1 |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 11870086 Country of ref document: EP Kind code of ref document: A1 |
|
| 32PN | Ep: public notification in the ep bulletin as address of the adressee cannot be established |
Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 19/09/2014) |