Xu Shishan

Bio: Xu Shishan is an academic researcher. The author has contributed to research in topics: Transformer & Partial discharge. The author has an hindex of 5, co-authored 15 publications receiving 48 citations.

Wide-range transformer iron core grounding current on-line monitoring sensing device

Abstract: The utility model discloses a wide-range transformer iron core grounding current on-line monitoring sensing device, which belongs to the technical field of electric engineering and relates to power transformer iron core grounding current on-line monitoring. The sensing device comprises a casing, grounding flat iron, a small-range current sensor and a large-range current sensor, wherein the grounding flat iron penetrates through the casing in up and down manner, the small-range current sensor and the large-range current sensor are arranged inside the casing and overlaid up and down; the small-range current sensor and the large-range current sensor are penetrating core hall current sensors, and the grounding flat iron insulated with the casing sequentially penetrates through the small-range current sensor and the large-range current sensor in up and down manner.

Local discharge testing method for +/- 400kV converter transformer

Abstract: The invention discloses a local discharge testing method for a +/- 400kV converter transformer. The local discharge testing method is designed for converter transformers of a Qaidam converter station of a Qinghai and Tibet +/- 400kV direct-current networking project. The local discharge testing method meets requirements of a high-altitude testing site, the specific structure and parameters of the converter transformer are overall considered and calculated in detail, a valve side y of the converter transfer is connected with one end of a winding terminal to boost voltage and excite, the other end of the valve side y is grounded, and accordingly specified testing voltage can be induced by a high-voltage winding on a net side.

A partial discharge testing device of a converter transformer at a high altitude locality

Abstract: The utility model discloses a partial discharge testing device of a converter transformer at a high altitude locality. The partial discharge testing device is mainly designed for partial discharge test of a plus-minus 400 kV converter transformer in Qaidam converter transformer station for Qinghai and Tibet networking engineering and comprises a variable-frequency power source without partial discharge, an exciting transformer without partial discharge, a compensation reactor without partial discharge, and a capacitive voltage divider without partial discharge. The variable-frequency power source without partial discharge is connected with two ends of the exciting transformer without partial discharge. One end of the compensation reactor without partial discharge is connected with ground, while the other end of the compensation reactor without partial discharge is connected with the output end of the exciting transformer without partial discharge. One end of the capacitive voltage divider without partial discharge is connected with ground, while the other end of the capacitive voltage divider without partial discharge is connected with the output end of the exciting transformer without partial discharge. The partial discharge testing device may satisfy operational requirement in the high altitude locality.

Detection method for field oil-gas online monitoring system

Abstract: The invention relates to the technical field of power supply and transformation, and particularly relates to a detection method for a field oil-gas online monitoring system. The method comprises the following steps: 1) switching on a transformer oil tank; 2) switching on an oil-gas online monitoring system with thermostatically controlled dynamic precision correction technology; 3) collecting calibrated oil chromatogram data; 4) monitoring oil and gas on line; 5) comparing data. The method has the advantages that the self-inspection requirement of the installed oil-gas online monitoring system can be met through the detection method; the problem that the accuracy and reliability of monitoring data of installed oil-gas online monitoring equipment are not high is well solved through error analysis report. The detection method for the field oil-gas online monitoring system disclosed by the invention can be used for parallel installation of the calibrated oil-gas online monitoring system, and also can be used for detecting the oil-gas online monitoring system independently.

In-situ local discharging test interference resistance method for converter transformer in high altitude areas

Abstract: The invention provides an in-situ local discharging test interference resistance method for a converter transformer in high altitude areas, and the method is characterized in that an equalizing ring which is applicable to the high altitude areas is respectively additionally installed on a compensation electric reactor, an excitation transformer and a converter transformer of a local discharging test system, and all devices are connected with one another through an expanded conducting wire with the diameter of 150mm; and the interference caused by the ambient test environment, test connecting wires, test method and the like in the high altitude areas can be effectively avoided, a purpose for precision in measurement can be realized, the situation of the transformer is further reasonably judged through reliable test data, and reliable judgment evidence can be provided for whether the converter transformer can be put into operation or not.

Converter transformer double side voltage applying partial discharge testing device and testing method thereof

Abstract: The invention discloses a converter transformer double side voltage applying partial discharge testing device and a testing method thereof The testing device is composed of a variable-frequency power supply P1, an exciting transformer T1, an exciting transformer T2, a compensation reactor L1, a compensator reactor L2, capacitive voltage dividers C1-C6, a partial discharge detector, a grounding terminal block Em and current transformers CT1-CT4 The invention provides a converter transformer double side voltage applying partial discharge testing method for the first time, and establishes a converter transformer double side voltage applying partial discharge test wiring method and converter transformer double side voltage applying partial discharge test procedures Compared with a traditional partial discharge method, the testing method disclosed by the invention greatly improves test effects and the test efficiency The converter transformer double side voltage applying partial discharge testing device and the testing method thereof have popularization values through experimental verification, and provide valuable guidance and reference for exploring a transformer partial discharge testing method

Method for extracting partial discharge waveform features of converter transformer

Abstract: The invention belongs to the technical field of partial discharge detection of high-voltage direct-current transmission equipment, discloses a method for extracting partial discharge waveform features of a converter transformer, and particularly relates to the method for extracting the partial discharge waveform features of the converter transformer on the basis of a multi-element feature extraction package. The method includes the steps that a file is read, screened and processed in advance, the multi-element feature extraction package is called, discharge waveform time-frequency spatial features are obtained, and the extracted partial discharge waveform spatial features are integrated and stored. The method is applied to partial discharge detection and insulation defect diagnosis of the converter transformer in a high-voltage direct-current transmission system. According to the purpose of partial discharge waveform feature extraction of the converter transformer, the concept that the multi-element feature extraction package is called is adopted, and the effective achieving method is provided. The method overcomes the defects of an existing method for extracting the partial discharge waveform features of the converter transformer and has the advantages of being rapid and accurate and features are comprehensive and detailed.

Distributed small current grounding line selection method based on double CT sampling

Abstract: The invention discloses a distributed small current grounding line selection method based on double CT sampling. According to the method, a double CT sampling loop is formed by a protection level transformer CT1 and a measurement level transformer CT2 which are connected in series with each other, zero sequence current I01 and I02 are obtained, and zero sequence voltage U0 of the system is also acquired and calculated. Whether U0 is greater than the zero sequence voltage threshold Uset is judged in the operation process, and the judgment result indicates single-phase grounding fault of the system if U0>Uset. Then whether I01 exceeds the measurement range of the measurement level transformer CT2 is judged, and I01 is taken as the zero sequence current I0 if the judgment result is yes; or I02 is taken as the zero sequence current I0. Finally integrated line selection logic judgment based on combination of the transient quantity and the steady-state quantity is performed according to the zero sequence current I0 and the zero sequence voltage U0. The advantages are that CT1 and CT2 are connected in series and then connected with the zero sequence CT so that the consistency of current input can be guaranteed, the accuracy and the range of the sampling data can be both considered and the line selection accuracy can be enhanced.

Testing device for long term voltage induction and partial discharge measurement test

Abstract: The invention discloses a testing device for long term voltage induction and a partial discharge measurement test. According to the testing device for the long term voltage induction and the partial discharge measurement test, a sine wave non-partial-discharge power source is used for matching with a non-partial-discharge exciting voltage transformer, a non-partial-discharge compensation reactor, a non-partial-discharge voltage divider and other non-partial-discharge measurement devices; the test is completed according to a parallel resonance principle. Accordingly, in a parallel circuit composed of a non-partial-discharge variable frequency power source, a tested voltage transformer equivalent capacitor and the non-partial-discharge compensation reactor, capacitive reactive power of a tested voltage transformer is exactly equal to inductive reactive power of the non-partial-discharge compensation reactor, energy can be exchanged between the tested voltage transformer equivalent capacitor and the non-partial-discharge compensation reactor, the non-partial-discharge variable frequency power source does not need to provide reactive power for the non-partial-discharge exciting voltage transformer and the non-partial-discharge compensation reactor, and the non-partial-discharge variable frequency power source only needs to provide resistive loss of a whole test return circuit.