Voltage Breakdown Test Instrument

1 Subject Content and Applicability Scope 

    This standard specifies two testing methods, namely MethodAPlease provide the Chinese content to be translated.BInsulation liquid assessment Electrical strength withstand standard lightning strikes in an electric field. 

    MethodA—— Step-stress testing method: Used to provide the insulation liquid lightning impulse breakdown voltage under specific conditions The estimated value. 

    MethodB——Sequential Testing Method: A statistical testing method used to assess the insulation liquid under a specific condition The assumption of breakdown probability under the impact of lightning impulse voltage. 

    This standard applies to both used and unused insulating liquids. The tested insulating liquids are40℃ viscosity The degree should be lower than700mm2/s。 

    Two methods can utilize impacts with both positive and negative polarities. However, these are used to assess the impact of chemical compositions on insulating liquids. When considering the effect of electrical shock breakdown voltage, it is preferable to use negative polarity shocks. 

    These two methods are primarily used for establishing standard procedures to evaluate the breakdown voltage of insulating liquids under lightning impulse. Both are: Available for assessing the lightning impulse characteristics of insulating liquids, as well as changes in production processes, composition, or oil sources. Variations in the breakdown voltage of lightning surge. 

2 Quoting Standards 

    GB 311.1～311.6 Insulation Coordination for High-Voltage Transmission and Transformation Equipment 

    GB 7597 Fuel for Power Use(Transformer oil, Turbine oil)Sampling Method 

3 Significance 

3.1 Insulating liquids used in electrical equipment may need to withstand transient voltages superimposed on the power frequency voltage during operation. The effect of operating voltage or lightning surge voltage. 

    Transient voltages, whether unidirectional or oscillating, will inevitably result in either a positive or negative polarity. The transient voltage action process. Therefore, it is essential to understand the characteristics of the insulating liquid under these conditions. 

    However, using a needle in the oil cup-Ball electrode experiments were conducted to obtain the breakdown voltage under impact and the actual insulation system. The relationship between the breakdown properties of insulating liquids and the unified medium requires further work. 

3.2 The breakdown of insulating liquids is a complex phenomenon that remains unclear to this day. In summary, breakdown requires intense... Propagation of Emission and Pre-breakdown Disturbances(Stream Column)。 

    Due to the fact that breakdown voltage depends on factors such as voltage waveform, the duration of voltage application, and electric field distribution, therefore, to achieve Achieving comparable results. All these factors must be clearly defined and strictly controlled. Despite this, the outcome There may still be considerable dispersion, which can be attributed to the randomness associated with the pre-breakdown mechanism.