Detection method of low frequency common mode interference of DC voltage

Abstract

The invention relates to a method for detecting low-frequency common-mode interference of DC voltage, and provides a test method for an AC voltage system and a low-voltage DC power supply integration system and especially for low-frequency band conducted transmission equipment below 9KHz so as to check whether conduction disturbance exists or not quickly and accurately and thus perform effective evaluation and limitation on a conducted transmission technology of inverter products. The detecting method is that monitoring is performed on grounding peak voltage of a low-voltage DC power supply terminal so as to judge whether a detected DC common mode has conduction disturbance or not. Specially, the method is more applicable to detecting common-mode disturbance voltage of a DC / AC inversion power supply module or device in a frequency band lower than 9KHz.

Description

technical field [0001] The invention proposes a method for testing and checking low-voltage and low-frequency DC common-mode disturbances, which is suitable for comprehensive integrated systems including AC voltage standard and low-voltage DC power supply, and belongs to the field of electrical design. Background technique [0002] The current national standard GB4824 2013 "Limits and Measurement Methods of Electromagnetic Disturbance Characteristics of Industrial, Scientific and Medical (ISM) Radio Frequency Equipment" has no limit for conducted emissions in the low-frequency band below 9KHz, and generally does not test conducted emissions in the frequency band below 9KHz. [0003] In the field of rail transit, there is no corresponding clear technical standard requirement for the ripple voltage generated by the inverter equipment at the DC power supply end. The usual way to test the ripple voltage is to test between the positive and negative lines of the DC terminal. If th...

AI Technical Summary

Problems solved by technology

In contrast, in the low-frequency band below 9KHz, the voltage disturbance intensity to the public ground will increase significantly, which will directly affect the normal and safe use of other equipment in the system. For components with high voltage sensitivity used on rail vehicles, it will Creates significant common mode disturbance problems

Also, depending on the device or circuit design, this disturbance can also affect other relatively low frequency bands where conducted emissions are measured

[0005] The existing simple instrument for testing voltage is a multimeter, and the test data result is generally an effective value, or an average value within a multi-cycle time, and cannot test the peak disturbance signal

If the peak duration of the disturbance signal is short but the period is long, it is impossible to use a multimeter for effective testing

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