技术领域technical field
本发明涉及变电站直流系统非接触式交直流串电的测试方法，包括非接触式交直流串电在线检测原理分析及方法和非接触式交直流串电在线检测系统构建。该方法及系统可在不接触变电站带电端子的情况下，方便用于变电站交流窜入直流系统的检测。该方法及系统属于电力自动化技术领域。The invention relates to a non-contact AC/DC series testing method for a DC system of a substation, including a non-contact AC/DC on-line detection principle analysis and method and a non-contact AC/DC on-line detection system construction. The method and the system can be conveniently used for detection of AC intrusion into a DC system of a substation without touching live terminals of the substation. The method and system belong to the technical field of electric power automation.
背景技术Background technique
直流电源系统作为变电站的重要组成部分，对保证全站设备的安全运行起到重要作用。它为信号设备、保护设备、断路器分合闸操作、事故照明等设备提供电源，其安全可靠运行对于变电站的安全可靠运行至关重要。但由于直流电源供电设备多，供电线缆长，在实际运行中经常出现直流接地、交流窜入直流系统等故障，其中交流窜入直流故障破坏性更大。由于一个屏柜内既有交流电，又有直流电，供电线缆又较长，交直流端子相隔较近，经常会因为误接线或绝缘降低，导致交流电窜入直流系统。交流窜入直流故障严重时会导致设备损坏，或保护设备误动，给变电站安全运行带来严重影响。As an important part of the substation, the DC power system plays an important role in ensuring the safe operation of the equipment in the whole station. It provides power for signaling equipment, protection equipment, circuit breaker opening and closing operations, emergency lighting and other equipment. Its safe and reliable operation is crucial to the safe and reliable operation of substations. However, due to the large number of DC power supply equipment and long power supply cables, faults such as DC grounding and AC intrusion into the DC system often occur in actual operation, among which AC intrusion into DC faults are more destructive. Since there are both AC and DC power in a panel cabinet, the power supply cable is long, and the AC and DC terminals are relatively close to each other, often the AC power will enter the DC system due to miswiring or insulation degradation. When the AC breaks into the DC fault seriously, it will cause equipment damage, or the protection equipment will malfunction, which will seriously affect the safe operation of the substation.
目前变电站现场对“交流窜入直流故障”缺乏有效的监控手段和故障告警措施，部分变电站安装了一种接在正负母线上，通过测量正母、负母对地电压在线检测直流系统中交流分量的装置。然而使用该装置存在两方面的隐患：1）装置可靠性对直流电源系统的影响，由于其接在正/负母与地之间，装置故障很有可能直接造成直流接地；2）装置安装工艺对运行设备的影响，对于已经投运变电站，由于与直流电源系统有电气连接，安装工艺差会直接影响到运行设备的正常工作。At present, the substation site lacks effective monitoring means and fault alarm measures for "AC intrusion into DC fault". weight device. However, there are two hidden dangers in the use of this device: 1) The reliability of the device affects the DC power system. Since it is connected between the positive/negative bus and the ground, the device failure is likely to directly cause DC grounding; 2) The installation process of the device Impact on operating equipment. For substations that have already been put into operation, due to the electrical connection with the DC power system, poor installation technology will directly affect the normal operation of operating equipment.
交直流串电在线检测技术现在尚未成熟，如何在保证直流系统稳定运行的前提下，准确地检测交流窜入直流故障已成为亟待解决的问题。The on-line detection technology of AC-DC series current is not yet mature. How to accurately detect the AC-DC fault under the premise of ensuring the stable operation of the DC system has become an urgent problem to be solved.
发明内容Contents of the invention
本发明所要解决的技术问题是在保证直流系统稳定运行的前提下，准确地检测交流电流窜入直流系统故障。The technical problem to be solved by the present invention is to accurately detect the fault of alternating current flowing into the direct current system under the premise of ensuring the stable operation of the direct current system.
为解决上述技术问题，本发明提供一种非接触式交直流串电在线检测装置，其特征在于，包括非接触式电压采集装置、数据采集板卡和非接触式交直流串电检测模块，所述非接触式电压采集装置包括非接触式电压钳，非接触式电压钳上设置有直流回路电缆夹口，所述测量电容一端连接至直流回路电缆夹口，另一端接地，同时测量电容两端分别连接至数据采集板卡，数据采集板卡输出端与非接触式交直流串电检测模块输入端连接，所述直流回路电缆夹口与电缆内导体之间形成非接触式耦合电容C1。In order to solve the above technical problems, the present invention provides a non-contact AC/DC on-line detection device, which is characterized in that it includes a non-contact voltage acquisition device, a data acquisition board and a non-contact AC/DC detection module. The non-contact voltage acquisition device includes a non-contact voltage clamp, the non-contact voltage clamp is provided with a DC circuit cable clamp, one end of the measurement capacitor is connected to the DC circuit cable clamp, and the other end is grounded, and the two ends of the capacitor are measured at the same time They are respectively connected to the data acquisition board, the output end of the data acquisition board is connected to the input end of the non-contact AC/DC series detection module, and a non-contact coupling capacitor C1 is formed between the clamp of the DC loop cable and the inner conductor of the cable.
前述的非接触式交直流串电在线检测装置，其特征在于，还包括告警输出模块，非接触式交直流串电检测模块输出端与告警输出模块连接。The aforementioned non-contact AC/DC on-line detection device is characterized in that it also includes an alarm output module, and the output terminal of the non-contact AC/DC detection module is connected to the alarm output module.
前述的非接触式交直流串电在线检测装置，其特征在于，告警输出模块是一个继电器。The aforementioned non-contact AC/DC on-line detection device is characterized in that the alarm output module is a relay.
前述的非接触式交直流串电在线检测装置，其特征在于，测量电容安装在非接触式电压钳内部。The aforementioned non-contact AC/DC on-line detection device is characterized in that the measuring capacitor is installed inside the non-contact voltage clamp.
前述的非接触式交直流串电在线检测装置，其特征在于，所述直流回路电缆夹口内表面为导电软体。The aforementioned non-contact AC/DC on-line detection device is characterized in that the inner surface of the DC loop cable clamp is made of conductive software.
前述的非接触式交直流串电在线检测装置，其特征在于，测量电容C2值为已知量。The aforementioned non-contact AC/DC on-line detection device is characterized in that the value of the measured capacitanceC2 is a known quantity.
前述非接触式交直流串电在线检测装置的在线检测方法，其特征在于，包括以下步骤：The online detection method of the aforementioned non-contact AC/DC series current online detection device is characterized in that it comprises the following steps:
1）对测量电容C2上分得交流电压分量Uac相应的交流电压U2进行测量；1) Measure the AC voltage U2 corresponding to the AC voltage component Uac divided on the measurement capacitor C2 ;
2）根据公式U2＝Uac*C1/(C1+C2)，计算交流电压分量Uac；2) According to the formula U2 =Uac *C1 /(C1 +C2 ), calculate the AC voltage component Uac ;
3）利用电压检测分析系统对交流电压分量Uac进行比较判断，将Uac与系统内部可设定的交流窜入告警电压Uzd进行比较，若Uac＞Uzd则通过告警输出模块发出交流窜入告警信号。3) Use the voltage detection and analysis system to compare and judge the AC voltage component Uac , compare Uac with the AC intrusion alarm voltage Uzd that can be set inside the system, and if Uac > Uzd , send an AC signal through the alarm output module Jump into the warning signal.
前述的非接触式交直流串电在线检测装置的在线检测方法，其特征在于，测量电容C2选与非接触式耦合电容C1同一数量级的电容。The aforementioned online detection method of the non-contact AC/DC series current detection device is characterized in that the measuring capacitance C2 is selected to be of the same order of magnitude as the non-contact coupling capacitance C1 .
本发明所达到有益效果：Beneficial effects achieved by the present invention:
本发明提出一种非接触式的交直流串电在线检测方法，并构建了非接触式交直流串电在线检测系统，非接触式交直流串电在线检测方法通过定制一个可拆卸的非接触式电容，套在变电站直流回路导线上，另外再通过一个分压电容，耦合出直流回路中的电压，经过折算分析，可以检测出直流回路中是否含有交流分量，实现了非接触式的交直流串电检测。The present invention proposes a non-contact AC/DC on-line detection method, and constructs a non-contact AC/DC on-line detection system. The non-contact AC/DC on-line detection method customizes a detachable non-contact The capacitor is set on the DC circuit wire of the substation, and the voltage in the DC circuit is coupled through a voltage dividing capacitor. After conversion analysis, it can be detected whether there is an AC component in the DC circuit, and a non-contact AC-DC series connection is realized. Electrical detection.
附图说明Description of drawings
图1为非接触式交直流串电检测系统示意图；Figure 1 is a schematic diagram of a non-contact AC/DC series detection system;
图2为非接触式交直流串电在线检测回路示意图；Fig. 2 is a schematic diagram of a non-contact AC/DC on-line detection circuit;
图3为非接触式交直流串电检测等值回路图。Figure 3 is an equivalent circuit diagram for non-contact AC/DC series detection.
具体实施方式Detailed ways
非接触式交直流串电在线检测系统：如图1所示，非接触式交直流串电在线检测系统利用非接触式耦合电容和测量电容检测直流回路中是否有交流电压分量的存在，从而检测是否有交流信号窜入直流系统。非接触式交直流串电在线检测系统包括：非接触式电压采集装置、数据采集板卡和非接触式交直流串电检测模块，所述非接触式电压采集装置包括非接触式电压钳，非接触式电压钳上设置有直流回路电缆夹口，所述测量电容一端连接至直流回路电缆夹口，另一端接地，同时测量电容两端分别连接至数据采集板卡，数据采集板卡输出端与非接触式交直流串电检测模块输入端连接，所述直流回路电缆夹口与电缆内导体之间形成非接触式耦合电容C1。Non-contact AC/DC series on-line detection system: As shown in Figure 1, the non-contact AC/DC on-line detection system uses non-contact coupling capacitors and measuring capacitors to detect whether there is an AC voltage component in the DC circuit, thereby detecting Whether there is AC signal escaping into the DC system. The non-contact AC/DC on-line detection system includes: a non-contact voltage acquisition device, a data acquisition board and a non-contact AC/DC detection module. The non-contact voltage acquisition device includes a non-contact voltage clamp. The contact voltage clamp is provided with a DC loop cable clamp, one end of the measurement capacitor is connected to the DC loop cable clamp, and the other end is grounded, and the two ends of the measurement capacitor are respectively connected to the data acquisition board, and the output end of the data acquisition board is connected to the The input end of the non-contact AC/DC series detection module is connected, and a non-contact coupling capacitor C1 is formed between the clamp of the DC loop cable and the inner conductor of the cable.
非接触式交直流串电检测模块是该系统的核心硬件模块，利用写入的软件实现非接触式回路电压测量，程序能够自动读取数据采集板卡采集的电压数据，并根据数据进行电压分析，检测其电压波形中的交流分量。通过计算交流电压有效值判断是直流二次回路受到扰动，还是直流系统中有交流窜入，具有一定的抗干扰性，保证直流系统有交流窜入时能准确发出告警信号。The non-contact AC/DC series detection module is the core hardware module of the system. The written software is used to realize the non-contact loop voltage measurement. The program can automatically read the voltage data collected by the data acquisition board and conduct voltage analysis according to the data. , to detect the AC component in its voltage waveform. By calculating the effective value of the AC voltage, it can be judged whether the DC secondary circuit is disturbed or there is AC intrusion in the DC system. It has certain anti-interference ability and can ensure that the alarm signal can be issued accurately when there is AC intrusion in the DC system.
非接触式电压钳用于形成非接触式耦合电容和测量电容，将非接触式电压钳夹在直流电缆回路上，直流回路电缆夹口1与电缆形成非接触式耦合电容，测量电容也安装在非接触式电压钳内部。交直流串电检测模块能否准确地测量直流系统中的交流分量很大程度上取决于非接触式电压钳的制作工艺。The non-contact voltage clamp is used to form a non-contact coupling capacitance and measurement capacitance. The non-contact voltage clamp is clamped on the DC cable loop, and the DC loop cable clamp 1 forms a non-contact coupling capacitance with the cable. The measurement capacitance is also installed on the Inside the non-contact voltage clamp. Whether the AC-DC series detection module can accurately measure the AC component in the DC system largely depends on the manufacturing process of the non-contact voltage clamp.
数据采集板卡用于测量电容的电压数据采集，并能储存电压波形。告警输出模块可以是一个继电器，当检测模块检测到有交流窜入直流系统时，告警输出模块可以发出告警信号，并根据需要将告警接点输出。The data acquisition board is used for the voltage data acquisition of the measured capacitance, and can store the voltage waveform. The alarm output module can be a relay. When the detection module detects that there is alternating current entering the DC system, the alarm output module can send out an alarm signal and output the alarm contact as required.
基于以上软件硬件模块构建非接触式交直流串电在线检测系统，如下图所示。该系统可以对直流电缆对地电压进行在线监视，检测是否有交流窜入直流系统。Based on the above software and hardware modules, a non-contact AC/DC online detection system is constructed, as shown in the figure below. The system can monitor the DC cable-to-ground voltage on-line, and detect whether there is AC intrusion into the DC system.
非接触式交直流串电在线检测方法：Non-contact AC/DC series on-line detection method:
非接触式交直流串电在线检测方法如图2所示，C1为非接触式耦合电容（通过裹在电缆外表面的导电软体与电缆内导体之间形成的电容）、测量电容C2、二次回路电压测量分析系统，即非接触式交直流串电检测模块为具备电压测量和波形分析的处理单元，C1和C2串联接地，其中C1大小可测得，C2大小已知。The non-contact AC/DC on-line detection method is shown in Figure 2. C1 is a non-contact coupling capacitor (capacitance formed between the conductive software wrapped on the outer surface of the cable and the inner conductor of the cable), the measuring capacitance C2 , The secondary circuit voltage measurement and analysis system, that is, the non-contact AC/DC series current detection module is a processing unit capable of voltage measurement and waveform analysis. C1 and C2 are connected in series and grounded, where the size of C1 can be measured and the size of C2 is known .
本发明的在线检测具体步骤包括：The specific steps of online detection of the present invention include:
1）对测量电容C2上分得交流电压分量Uac相应的交流电压U2进行测量；1) Measure the AC voltage U2 corresponding to the AC voltage component Uac divided on the measurement capacitor C2 ;
2）根据公式U2＝Uac*C1/(C1+C2)，计算交流电压分量Uac；2) According to the formula U2 =Uac *C1 /(C1 +C2 ), calculate the AC voltage component Uac ;
3）利用电压检测分析系统对交流电压分量Uac进行比对判断，将Uac与系统内部可设定的交流窜入告警电压Uzd进行比较，若Uac＞Uzd则通过告警输出模块发出交流窜入告警信号。3) Use the voltage detection and analysis system to compare and judge the AC voltage component Uac , and compare Uac with the AC intrusion alarm voltage Uzd that can be set inside the system. If Uac > Uzd , it will be sent through the alarm output module AC break-in warning signal.
如图2所示，由于交流系统为接地系统，当二次回路电缆由于绝缘问题导致交流入侵时，必定能在电缆对地电压中测量到交流分量。二次回路电缆对地电压会在非接触式耦合电容C1和测量电容C2上形成分压，二次回路电压测量分析系统检测测量电容的电压，进而通过分析计算得到二次回路电缆的对地电压。As shown in Figure 2, since the AC system is a grounding system, when the secondary circuit cable causes AC intrusion due to insulation problems, the AC component must be measured in the cable-to-ground voltage. The voltage of the secondary circuit cable to ground will form a partial voltage on the non-contact coupling capacitor C1 and the measuring capacitor C2 , the secondary circuit voltage measurement and analysis system detects the voltage of the measuring capacitor, and then obtains the secondary circuit cable pair through analysis and calculation ground voltage.
假设二次回路电缆对地电压为U，当有交流窜入直流系统时，其包含直流分量Udc和交流分量Uac,则U＝Udc+Uac。其等值回路如图3所示：Assuming that the voltage of the secondary circuit cable to ground is U, when there is alternating current flowing into the direct current system, it contains the direct current component Udc and the alternating current component Uac , then U=Udc +Uac . Its equivalent circuit is shown in Figure 3:
U1、U2分别是非接触式耦合电容和测量电容上分得的电压，根据电路理论，二次回路电缆对地电压中的交流分量Uac在测量电容上分得的电压U2＝Uac*C1/(C1+C2)。由于电容“隔直通交”作用，直流分量Udc在电容上分得电压均为零。U1 and U2 are the voltages obtained from the non-contact coupling capacitor and the measuring capacitor respectively. According to the circuit theory, the voltage U2 = Uac obtained by the AC component Uac in the voltage of the secondary loop cable to ground on the measuring capacitor *C1 /(C1 +C2 ). Due to the function of "blocking direct and passing through" of the capacitor, the voltage of the direct current component Udc on the capacitor is zero.
上述分析可知，只有二次回路电缆窜入交流分量时，测量电容上才会测得交流电压U2。由于非接触式耦合电容C1无法精确测量，且对于不同系统其电容值不相同，但是可测得大概的数量级。为了尽可能准确地获得测量电容的电压，选择测量电容时应选择与非接触式耦合电容同一数量级的电容。From the above analysis, it can be seen that the AC voltage U2 can be measured on the measuring capacitor only when the secondary circuit cable enters the AC component. Since the non-contact coupling capacitanceC1 cannot be measured accurately, and its capacitance value is different for different systems, but it can be measured to an approximate order of magnitude. In order to obtain the voltage of the measurement capacitance as accurately as possible, the capacitance of the same order of magnitude as the non-contact coupling capacitance should be selected when selecting the measurement capacitance.
通过二次回路电压测量分析系统对回路电压进行在线监视，并对采集的电压波形进行分析，可以计算出回路中交流电压分量，进而判断直流回路中是否有交流窜入。Through the secondary circuit voltage measurement and analysis system to monitor the circuit voltage online, and analyze the collected voltage waveform, the AC voltage component in the circuit can be calculated, and then it can be judged whether there is AC intrusion in the DC circuit.
本发明中提出的非接触式交直流串电在线检测方法及构建的在线检测系统在实验室进行试验验证。通过在直流系统中注入交流电源的方法，使得直流系统中有交流入侵，评估该发明中交直流串电在线检测方法的有效性和检测系统的实用性。检测结果表明，利用该检测系统能快速、准确的反应出直流系统中是否有交流窜入。The non-contact AC/DC on-line detection method proposed in the present invention and the constructed on-line detection system are tested and verified in the laboratory. Through the method of injecting AC power into the DC system, there is AC intrusion in the DC system, and the effectiveness of the online detection method of AC-DC series power in the invention and the practicability of the detection system are evaluated. The detection results show that the detection system can quickly and accurately reflect whether there is AC intrusion in the DC system.
以上已以较佳实施例公开了本发明，然其并非用以限制本发明，凡采用等同替换或者等效变换方式所获得的技术方案，均落在本发明的保护范围之内。The above has disclosed the present invention with preferred embodiments, but it is not intended to limit the present invention, and all technical solutions obtained by adopting equivalent replacement or equivalent transformation methods fall within the protection scope of the present invention.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310227064.0ACN103323655B (en) | 2013-06-08 | 2013-06-08 | Non-contact alternating current and direct current crosstalk online detecting device and non-contact alternating current and direct current crosstalk online detecting method |
| Application Number | Priority Date | Filing Date | Title |
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| CN201310227064.0ACN103323655B (en) | 2013-06-08 | 2013-06-08 | Non-contact alternating current and direct current crosstalk online detecting device and non-contact alternating current and direct current crosstalk online detecting method |
| Publication Number | Publication Date |
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| CN103323655A CN103323655A (en) | 2013-09-25 |
| CN103323655Btrue CN103323655B (en) | 2015-04-29 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310227064.0AActiveCN103323655B (en) | 2013-06-08 | 2013-06-08 | Non-contact alternating current and direct current crosstalk online detecting device and non-contact alternating current and direct current crosstalk online detecting method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105116352B (en)* | 2015-09-01 | 2018-06-26 | 国网辽宁省电力有限公司鞍山供电公司 | The double set DC power system string electro-detection methods of substation |
| US10359494B2 (en)* | 2016-11-11 | 2019-07-23 | Fluke Corporation | Proving unit for non-contact voltage measurement systems |
| CN110940928B (en)* | 2019-12-13 | 2025-05-27 | 上海华电电力发展有限公司望亭发电分公司 | A device for detecting AC intrusion in a power plant DC system |
| CN113552501A (en)* | 2020-04-24 | 2021-10-26 | 青岛海尔智能技术研发有限公司 | Circuit for leakage detection and electric water heater |
| CN113552500A (en)* | 2020-04-24 | 2021-10-26 | 青岛海尔智能技术研发有限公司 | Circuit for electric leakage detection, method for electric leakage detection of electric appliance and electric water heater |
| CN113238089B (en)* | 2021-06-11 | 2022-07-01 | 广西电网有限责任公司电力科学研究院 | Non-contact voltage measurement method, device, computer equipment and storage medium |
| CN113176441B (en)* | 2021-06-11 | 2022-07-01 | 广西电网有限责任公司电力科学研究院 | Non-contact voltage measuring device and method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102156218A (en)* | 2011-03-17 | 2011-08-17 | 重庆大学 | Device and method for measuring voltage of noncontact charge induced high-voltage transmission line |
| CN102636724A (en)* | 2012-05-08 | 2012-08-15 | 河北省电力公司超高压输变电分公司 | Portable multi-functional serial crosstalk detector |
| CN202421312U (en)* | 2011-12-20 | 2012-09-05 | 首瑞（北京）投资管理集团有限公司 | Device for monitoring alternating current being in series connection with direct current system |
| CN202710647U (en)* | 2012-08-02 | 2013-01-30 | 温州市科星电子有限公司 | Monitoring device for direct current system |
| CN103116087A (en)* | 2012-09-26 | 2013-05-22 | 珠海瑞特电气设备有限公司 | Electric power alternating current-direct current (AC/DC) power source crosstalk computer monitoring protective device |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9063184B2 (en)* | 2011-02-09 | 2015-06-23 | International Business Machines Corporation | Non-contact current-sensing and voltage-sensing clamp |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102156218A (en)* | 2011-03-17 | 2011-08-17 | 重庆大学 | Device and method for measuring voltage of noncontact charge induced high-voltage transmission line |
| CN202421312U (en)* | 2011-12-20 | 2012-09-05 | 首瑞（北京）投资管理集团有限公司 | Device for monitoring alternating current being in series connection with direct current system |
| CN102636724A (en)* | 2012-05-08 | 2012-08-15 | 河北省电力公司超高压输变电分公司 | Portable multi-functional serial crosstalk detector |
| CN202710647U (en)* | 2012-08-02 | 2013-01-30 | 温州市科星电子有限公司 | Monitoring device for direct current system |
| CN103116087A (en)* | 2012-09-26 | 2013-05-22 | 珠海瑞特电气设备有限公司 | Electric power alternating current-direct current (AC/DC) power source crosstalk computer monitoring protective device |
| Publication number | Publication date |
|---|---|
| CN103323655A (en) | 2013-09-25 |
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