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Combination Wave Generator and its Automatic Test System

Author:Chen Jingliang Sun Wei Yao Xueling Liu Dongshe Xing Juxian
School:Xian Jiaotong University,School of Electrical Engineering

1. The scientific field of the project
The project falls into the field of applied sciences. It is a new-type high-voltage test device used to simulate the actual action of the instantaneous interference effect of the thunder and lightning on the test specimen. The specific features are as follows: When the test specimen is of high resistance, the system generates open-circuit voltage waves of 1.2/50¦МS; and when the test specimen is of low resistance, short-circuit current waves of 8/20¦МS are generated. The project, which combines the conventional high-voltage technique with the computer technique, data communication and measurement and automatic control theory, is an automatic system for the high-voltage test in the strong electromagnetic environment.
2. Main contents of the project
The system has been successfully applied to the combination wave test and voltage limitation test and experiment for low-voltage lightning protection (SPD). It is a high-voltage test system for the low-voltage lightning protection. It is a high-voltage test system for the trade producing electric elements and devices (SPD). The system is an indispensable test device in the production process and research. Considering the current rapid development of the low-voltage lightning protection and the recent implementation of the relevant state standard on SPD, the research and development on the combination wave generator and its automatic test system will provide the test of SPD with an automatic test system featuring high automation, reliability, precision, and performance, and multiple function. This is of active significance to the heightening of the research level and promotion of the rapid development of the trade concerned.
3. Specific features of the project
1) High technical indexes: The open-circuit voltage is 1.2/50¦МS (30kV) and the short-circuit current is 8/20¦МS(15kV). These parameters are much higher than those reported by the domestic enterprises and joint ventures in China and identical with the indexes of the internationally famed brands.
2) High measurement precision: The total uncertainty of the system is 1.58%, which is higher by 3% than the standard specified by IEC and GB.
3) High automation level. The automatic system consists of PLC, MPT, industrial controller, single-chip processor and main circuit, controlled high-voltage discharge switch, and relevant mechanisms. It is possible to realize the full automatic test process involving mutual communication between systems, data gathering and processing, programmed control, etc.
4) Adoption of the Ў°simulation voltage digital tracingЎ± technique. The range of the voltage reliably triggered by the controlled high-voltage discharge switch designed is wide (within 30kV). The control precision is ЎА 0.01mm. There is satisfactory stability for safe operation.
5) Complete functions: The discharge voltage, discharge times and intervals can be preset. The precise control of the discharge clearance by the controllable switch can be implemented by using the Ў°simulation voltage digital tracingЎ± technique. By use of the Ў°digital pulse countingЎ± method, the phase tracing of the 0-360o scope of the sine wave can be precisely realized. The tracing precision is ЎА 1o. It is possible to realize the storage and printing of the waveform and data. It is possible to display on-line the condition of the process control, test data (current and voltage), wave parameters (wave front time, half peak time and anti-polarity oscillation), etc. The test specimen can be categorized and deleted.
4. Popularization
The results of the project have been applied successfully to the domestic production and research units such as the XiЎЇan No. 2 Radio Factory, Shanghai Electric Devices Research Institute, and Yuquan Electric Equipment and Materials Company, Limited (Dongguan). The application mainly goes to the action load and limited voltage tests and anti-deflection tests of surging (impact) for the equipment under test (EUT). Moreover, the system has an extensive application prospect in the electromagnetic compatibility (EMC) trade concerning the electronic equipment thunder strike and the lightning protection aspects of the weather, communication, construction, railway and fire control departments. In a word, the development of the automatic test system of the combination wave generator will provide a high-precision, high-reliability and easy operability for the research on low-voltage lightning protection. The development is of great significance to the improvement of the research electromagnetic compatibility and thunder strike tests of the electronic equipment.