Li Xin

Bio: Li Xin is an academic researcher. The author has contributed to research in topics: Circuit breaker & High voltage. The author has an hindex of 3, co-authored 12 publications receiving 24 citations.

Calibration device and calibration method for calibrating performance of ultrasonic partial discharge sensor

Abstract: The invention discloses a calibration device and a calibration method for calibrating the performance of ultrasonic partial discharge sensors. The device comprises a frequency modulation and amplitude modulation sine signal generator, an acoustic emission sensor, a test block, a reference sensor, an oscilloscope and a signal acquisition module. The output end of the frequency modulation and amplitude modulation sine signal generator is connected with the acoustic emission sensor. The acoustic emission sensor is arranged at one side of the test block. The reference sensor and a tested ultrasonic partial discharge sensor are arranged at the other side of the test block. The output end of the reference sensor is connected with the oscilloscope. The tested ultrasonic partial discharge sensor outputs detected ultrasonic signals through the signal acquisition module. The method comprises linearity calibration and stability calibration. The problem on performance calibration of ultrasonic sensors is solved. The device and the method are easy to implement. The performance calibration requirement of ultrasonic partial discharge detectors can be met. The amplitude and frequency of the frequency modulation and amplitude modulation sine signal generator are convenient to adjust.

Real defects simulation of type high voltage circuit breaker mechanism and branch closing coils current?detection?device

Abstract: The utility model discloses a real defects simulation of type high voltage circuit breaker mechanism and branch closing coils current?detection?device, including high voltage circuit breaker, circuit breaker deciliter brake controller, a direct current transformer, the 2nd direct current transformer, branch closing coils current detector, circuit breaker deciliter brake controller is connected with high voltage circuit breaker's divide -shut brake control line respectively, a direct current transformer presss from both sides on high voltage circuit breaker's closing coils for acquire closing coils's induced -current, the output is connected with dividing closing coils current detector, the 2nd direct current transformer presss from both sides on high voltage circuit breaker's separating brake coil for acquire the induced -current of separating brake coil, the output is connected with dividing closing coils current detector. The utility model has the advantages of can make things convenient for, swiftly, true, reliable various defects of simulation high voltage circuit breaker, the branch closing coils electric current to the high voltage circuit breaker under the various malfunctions that can be convenient is studied.

Acquisition method and device of substation partial discharge live detection electromagnetic interference

Abstract: The invention discloses an acquisition method and device of substation partial discharge live detection electromagnetic interference. The method includes the following steps that: coupling type electromagnetic interference signals of detected electromagnetic interferences are acquired through an ultrahigh-frequency antenna and a transient ground voltage capacitance sensor respectively, and conduction type electromagnetic interference signals of the detected electromagnetic interferences are acquired through a high-frequency Rogowski coil; and signal conditioning is performed on the acquired electromagnetic interferences, and the conditioned electromagnetic interferences are outputted. The acquisition device includes an electromagnetic interference signal sensitive unit and a signal conditioning unit; the electromagnetic interference signal sensitive unit includes the ultrahigh-frequency antenna and the transient ground voltage capacitance sensor which are used for acquiring the coupling type electromagnetic interference signals, and the high-frequency Rogowski coil which is used for detecting the conduction type electromagnetic interference signals; and the output ends of the ultrahigh-frequency antenna, the transient ground voltage capacitance sensor and the high-frequency Rogowski coil are connected with the signal conditioning unit respectively. The acquisition method and device of the invention can acquire and inhibit complex interference signals of which the frequency band is overlapped with that of partial discharge signals, and have the advantages of high detection accuracy, excellent detection sensitivity and convenient field detection.

Real type high voltage circuit breaker energy storage part defects simulation and detection device

Abstract: The utility model discloses a real type high voltage circuit breaker energy storage part defects simulation and detection device, including high voltage circuit breaker, breaker operating characteristic tester, energy storage motor current detection appearance, direct current transformer, spring pressure sensor and spring pressure sensor, the divide -shut brake control line of breaker operating characteristic tester inserts high voltage circuit breaker's divide -shut brake control return circuit, direct current transformer presss from both sides in high voltage circuit breaker's energy storage loop, and its signal output line inserts energy storage motor current detection appearance, spring pressure sensor installs at high voltage circuit breaker combined floodgate energy -stored spring and separating brake energy -stored spring lower extreme, and its signal output line inserts spring pressure sensor. The utility model discloses can effectively simulate the easy multiple defect that appears of actual high voltage circuit breaker operation in -process energy storage part to energy storage motor electric current, spring pressure when detecting the defect, the defect is all realized by the original parts of circuit breaker, can realize the switching of different grade type defect through the defective parts in dismouting area.

Electrified collection system who detects electromagnetic interference is put in office of transformer substation

Abstract: The utility model discloses an electrified collection system who detects electromagnetic interference is put in office of transformer substation, including the sensitive unit (1) of electromagnetic interference signal and signal conditioning unit (2), electromagnetic interference signal sensitive unit (1) is including ultrahigh frequency antenna (11) and the transient state ground voltage capacitive sensor (12) who is used for gathering coupled mode electromagnetic interference signal, the high frequency luo shi coil (13) that is used for detecting conduction type electromagnetic interference signal, the output of ultrahigh frequency antenna (11), transient state ground voltage capacitive sensor (12), high frequency luo shi coil (13) links to each other with signal conditioning unit (2) respectively. The utility model has the advantages of can gather to restrain and put the complicated interfering signal that the signal has the band overlapping with the office, detection accuracy is high, detectivity is good, the witnessed inspections is convenient.

Examination and verification device for noncontact ultrasonic method partial discharge detector and examination and verification method thereof

Abstract: The invention discloses an examination and verification device for a noncontact ultrasonic method partial discharge detector and an examination and verification method thereof The device part comprises a signal excitation source, an ultrasonic transducer module, a verification platform, a reference sensor, an oscilloscope and a 50ohm coaxial cable A detected instrument comprises a detected sensor and a partial discharge detector The detectable items include sensitivity, detection frequency band, linearity and stability The test method is easy to realize and easy and rapid to debug, and the test process is convenient and rapid so that the device is suitable for routine maintenance, testing, correction and other performance examination of the noncontact ultrasonic method partial discharge detector of the power detection industry and can guarantee effectiveness and reliability of the detection instrument

Ultrasonically local discharging metering system under onsite environment and method

Abstract: The invention discloses an ultrasonically local discharging metering system under an onsite environment. The system comprises a background control platform and a far-end measuring device, wherein the background control platform comprises an upper computer and a first optical emitting receiving module; the upper computer is connected with the first optical emitting receiving module; the far-end measuring device comprises a second optical emitting receiving module, a standard signal generating module, a standard signal modulating module, a broadband power amplifying module, an impedance matcher, an ultrasonic transducer, a standard sound sender, a broadband sound emitting collecting module, a digital encoder and a far-end battery power supply module. The ultrasonically local discharging metering system under the onsite environment provided by the invention can enhance the technical management capacity for the accuracy and reliability of ultrasonic local discharging overhaul measuring data, can efficiently monitor the reliability of the measuring data of an electrifying detector and an online monitoring device in a running process and can monitor the accuracy and reliability of the measuring data of an ultrasonic local discharging online monitoring device.

Acquisition method and device of substation partial discharge live detection electromagnetic interference

Abstract: The invention discloses an acquisition method and device of substation partial discharge live detection electromagnetic interference. The method includes the following steps that: coupling type electromagnetic interference signals of detected electromagnetic interferences are acquired through an ultrahigh-frequency antenna and a transient ground voltage capacitance sensor respectively, and conduction type electromagnetic interference signals of the detected electromagnetic interferences are acquired through a high-frequency Rogowski coil; and signal conditioning is performed on the acquired electromagnetic interferences, and the conditioned electromagnetic interferences are outputted. The acquisition device includes an electromagnetic interference signal sensitive unit and a signal conditioning unit; the electromagnetic interference signal sensitive unit includes the ultrahigh-frequency antenna and the transient ground voltage capacitance sensor which are used for acquiring the coupling type electromagnetic interference signals, and the high-frequency Rogowski coil which is used for detecting the conduction type electromagnetic interference signals; and the output ends of the ultrahigh-frequency antenna, the transient ground voltage capacitance sensor and the high-frequency Rogowski coil are connected with the signal conditioning unit respectively. The acquisition method and device of the invention can acquire and inhibit complex interference signals of which the frequency band is overlapped with that of partial discharge signals, and have the advantages of high detection accuracy, excellent detection sensitivity and convenient field detection.

Method for grading transformer station partial discharge live detection electromagnetic interference signals

Abstract: The invention discloses a method for grading transformer station partial discharge live detection electromagnetic interference signals. The method performs classified statistic on various kinds of electromagnetic interference signals in various detection methods, uses the interference signal intensity and discrete degree thereof as the basis of interference grading, objectively and accurately grades the interference grades of the electromagnetic interference signals, quantitatively describes the electromagnetic interference signals, and provides a reference basis for a standardized interference test platform and establishment of a partial discharge detection device anti-interference performance evaluation system.

Cable oscillating wave local discharge fault positioning system

Abstract: The invention discloses a cable oscillating wave local discharge fault positioning system. The cable oscillating wave local discharge fault positioning system comprises a high-frequency current sensor; the high-frequency current sensor inputs a sensed local discharge signal to a presignal wave detector; the presignal wave detector judges the signal, and controls a subsequent variable gain amplifier to select direct connection or an amplification factor; then, the signal is amplified by the variable gain amplifier and then enters a high-speed AD collection card for AD conversion; and data are transmitted to an upper computer for analysis, processing and display. According to the cable oscillating wave local discharge fault positioning system, by increasing the presignal wave detector and the variable gain amplifier, an amplitude of a reflection signal is significantly improved, and an AD collection effect is improved; and meanwhile, correlation operation is adopted for sampled data andwaveform matching is performed on a waveform characteristic algorithm, so that a matching effect is improved to the utmost extent, an identification effect on the sensed signal in two times is greatlyimproved, and the fault positioning precision is effectively improved.