WO2013104197A1 - Method for testing electromagnetic compatibility of electronic mutual inductor - Google Patents

Abstract

A method for testing electromagnetic compatibility of an electronic mutual inductor. A test voltage amplitude output by a high-voltage transformer is the same as a rated operational voltage of a major loop of a tested electronic mutual inductor, and the capacity of a load capacitor is selected under a condition that a steady-state current value is 0.5 A with a disconnecting switch being switched for connection. A primary part, a secondary connection, and an electronic merging unit of the tested electronic mutual inductor are systematically assembled and connected according to actual working conditions, and during the test, the electronic mutual inductor is powered and operates in a normal working manner. In a process that the disconnecting switch is switched for disconnecting or connecting the capacitor, an arc breakdown and extinction transient process occurs multiple times in the major loop, and a pulse current, a transient overvoltage, and a pulse magnetic field are produced multiple times in the transient process. According to numerical values of voltage and current waveforms measured once, an output characteristic and a working state of the electronic mutual inductor are subject to comparison, so as to determine the electromagnetic interference resistance performance of the electronic mutual inductor, thereby improving the reliability of on-site operation of the electronic mutual inductor and reducing the failure rate of the device.

Description

 Test method for electromagnetic compatibility of electronic transformers

 The invention belongs to the field of electromagnetic compatibility test and measurement, and particularly relates to a test method for electromagnetic compatibility of an electronic transformer of an isolation switch for capacitive current test.

Background technique

 At present, the electromagnetic compatibility of electronic transformer products is carried out in accordance with the national standard "GB/T 17626 Electromagnetic Compatibility". The products are in the actual operation process of the power system under the conditions that the specified electromagnetic compatibility test items are completed and the test results are qualified. Multiple failures in electromagnetic protection performance occurred in the middle. Through experimental research and theoretical analysis, the electromagnetic compatibility of electronic transformers cannot meet the electromagnetic environment requirements of power systems. The main reasons are:

 1) The national standard stipulates that a single test project is carried out at the same time, that is, the test only has a single source of disturbance, such as an electrical fast transient pulse group, a surge, a pulsed magnetic field, and the like. The actual source of disturbance on the site is the simultaneous occurrence of multiple parameters of disturbance sources, such as transient voltage, transient magnetic field, and transient current. Under the same conditions, multiple parameter disturbance sources are applied at the same time more severely than single-parameter sources of disturbance.

 2) The individual test parameters specified by the national standard differ greatly from the actual on-site measurement parameters, such as the 15ms pulse group applied by the electrical fast transient pulse group, the interval is 300ms, the transient pulse generated by the actual isolation switch, the pulse during one operation is Continuously, longer pulse durations can be above Is. Intensive long-term transient pulses are more stringent in product evaluation.

3) The electronic transformer electromagnetic compatibility test items specified by the national standard and the actual use voltage level are not turn off. According to experimental research and theoretical analysis, the characteristic parameters of the disturbance source are closely related to the voltage level, and the higher the voltage level, the stronger the electromagnetic interference.

 4) Most of the test items specified by the national standard are component-level tests, that is, mainly testing various components of electronic transformers, lacking system-level electromagnetic compatibility test items, and system-level electromagnetic compatibility test items and actual operating conditions. Close.

Summary of the invention

 In order to overcome the above deficiencies, the present invention proposes a test method for electromagnetic compatibility of an electronic transformer, by which the on-site operational reliability of the electronic transformer is improved, and equipment failure due to insufficient electromagnetic protection performance is reduced.

 The technical solution of the present invention is implemented as follows: The following steps are included:

 1) The high voltage output of the high voltage transformer is connected to one end of the isolating switch, and a set of capacitive voltage dividers are connected in parallel; the other end of the isolating switch is connected in parallel with a set of capacitive voltage divider, load capacitor and electronic voltage transformer under test, and standard current sensor Before the electronic current transformer is connected in series with the load capacitor, the output direction of the high voltage power supply is the front end, and the electronic voltage transformer to be tested and the electronic current transformer under test are simultaneously present or only one of them;

 2) The standard measuring device and the tested electronic transformer are powered up in normal working condition;

 3) The isolating switch is in the open state;

 4) The high voltage test transformer is energized and raised to the rated working voltage of the electronic transformer under test;

5) Close the isolation switch and record the output signals of the standard measuring equipment and the electronic transformer;

6) Interval time 1~5 minutes, separate the isolating switch, and record the output signals of standard measuring equipment and electronic transformer;

7) Repeat 5~6 times to perform multiple times and 10 times to divide the operation; 8) The high voltage test transformer is stepped down and power is cut off;

 9) The test is over;

 In the test process, the electronic transformer does not appear in the device, the communication fault, and the output waveform data is not abnormal with the standard waveform data. The electronic transformer test is qualified.

 The disturbance source generated by the capacitive switch is used to simulate the actual working conditions of the power system. This kind of disturbance source has the characteristics of simultaneous application of multiple parameters such as transient pulse voltage, pulse current and pulse magnetic field, and long duration. At the same time, the voltage level factor is included in the test parameters, and the actual test results are good. This method is used to test the system-level anti-interference performance of the electronic transformer, which can significantly improve the anti-jamming performance of the electronic transformer and reduce the failure rate of the electronic transformer during use.

DRAWINGS

 Figure 1 is a schematic diagram of the test wiring of the isolated capacitive capacitive current disturbance source.

 In the picture:

 B high voltage test transformer;

 P1 high voltage power supply capacitor divider; (standard voltage sensor)

 P2 high voltage load side capacitor divider;

 CT1 load current measuring transformer (standard current sensor);

 CT2 tested electronic current transformer;

 PT tested electronic voltage transformer;

 C load capacitor

K isolating switch; according to the matching mode of electronic transformer, AIS isolating switch (air insulation) and GIS isolating switch (gas fully enclosed combination). The contents of the present invention will be further described in detail below with reference to the accompanying drawings.

detailed description

 Referring to Figure 1, the test voltage amplitude of the high-voltage transformer is the same as the rated main circuit voltage of the tested electronic transformer. The capacity of the load capacitor is selected according to the steady-state current value of 0.5A after the isolation switch is turned on. The tested electronic transformer is once. The partial, secondary connection and electronic merging unit are connected according to the actual working conditions. During the test, the electronic transformer is energized and operates in the normal working mode. In the process of splitting or combining capacitors, the isolating process will generate multiple arc breakdown and extinction transient processes in the main circuit. This transient process will generate multiple pulse currents and transient overvoltages (operated by GIS isolation switch, which will generate Very fast transient over-voltage VFTO) and pulsed magnetic field, measuring and recording the voltage and current and the output value and working state of the electronic transformer. According to the measurement of the voltage and current waveform value, the output characteristics and working state of the electronic transformer are compared. Electromagnetic anti-jamming performance of the transformer.

 Test steps:

 1) The high voltage output of the high voltage transformer is connected to one end of the isolating switch, and a set of capacitive voltage dividers are connected in parallel; the other end of the isolating switch is connected in parallel with a set of capacitive voltage divider, load capacitor and electronic voltage transformer under test, and standard current sensor Before connecting the measured electronic current transformer to the load capacitor (the high-voltage power supply output direction is the front end). The measured electronic voltage transformer and the measured electronic current transformer can exist at the same time or only one of them.

 2) The standard measuring device and the tested electronic transformer are powered up in normal working condition.

 3) The isolating switch is in the open state;

 4) The high voltage test transformer is energized and raised to the rated working voltage of the electronic transformer under test.

5) Close the isolation switch and record the output signals of the standard measuring equipment and the electronic transformer. 6) At intervals (1 to 5 minutes), separate the isolating switch and record the output signals of the standard measuring device and the electronic transformer.

 7) Repeat 5~6 steps for multiple times (recommended 10 points).

 8) The high voltage test transformer is stepped down and power is cut off.

 9) The test is over.

 Test criteria:

 In the test process, the electronic transformer does not appear in the device, the communication fault, and the output waveform data is not abnormal with the standard waveform data. The electronic transformer test is qualified.

Claims

Claim

 1. A test method for electromagnetic compatibility of an electronic transformer, characterized in that it comprises the following steps:

 1) The high voltage output of the high voltage transformer is connected to one end of the isolating switch, and a set of capacitive voltage dividers are connected in parallel; the other end of the isolating switch is connected in parallel with a set of capacitive voltage divider, load capacitor and electronic voltage transformer under test, and standard current sensor Before the electronic current transformer is connected in series with the load capacitor, the output direction of the high voltage power supply is the front end, and the electronic voltage transformer to be tested and the electronic current transformer under test are simultaneously present or only one of them;

 2) The standard measuring device and the tested electronic transformer are powered up in normal working condition;

 3) The isolating switch is in the open state;

 4) The high voltage test transformer is energized and raised to the rated working voltage of the electronic transformer under test;

5) Close the isolation switch and record the output signals of the standard measuring equipment and the electronic transformer;

6) Interval time 1~5 minutes, separate the isolating switch, and record the output signals of standard measuring equipment and electronic transformer;

 7) Repeat 5~6 times to perform multiple times and 10 times to divide the operation;

 8) The high voltage test transformer is stepped down and power is cut off;

 9) The test is over;

 Test criteria:

 In the test process, the electronic transformer does not appear in the device, the communication fault, and the output waveform data is not abnormal with the standard waveform data. The electronic transformer test is qualified.