Application Cases

Experiment Title: Surface Potential Decay Theory and Testing System

Testing Purpose:Surface potential decay involves charging the surface of insulating materials through corona discharge. During the charging process, charges from the corona enter the material. Based on the trap theory, these space charges are captured by traps within the material, forming surface potential. The other side of the material is connected to a ground electrode. After the external voltage is removed, the trapped charges gradually detrapping leads to the potential decay process. The potential decay is primarily due to the detrapping charges flowing into the ground electrode through charge transport.

Testing Equipment: High Voltage Amplifier, High Voltage DC Power Supply, Signal Generator, High Voltage Probe, High-Speed High Voltage Electrostatic Voltmeter, Computer, etc.

Experiment Process:

Figure 1: Surface Potential Decay Testing System

A surface potential decay testing system was built based on the above theory, as shown in Figure 1. The testing system mainly consists of a pressurization module, a measurement module, a temperature control module, a transmission module, and a data acquisition module. The pressurization module includes a high voltage DC power supply, a high voltage amplifier, and a signal generator. The electrode module includes a needle electrode connected to the high voltage amplifier, a grading mesh (grid electrode) connected to the high voltage DC power supply, and a ground electrode connected to the other side of the sample. The transmission module mainly consists of a conveying track connected to the ground electrode and a control system, which can uniformly and quickly move the sample under the high voltage probe. The temperature control module mainly consists of a heating belt connected to the ground electrode and a temperature control system to ensure that the material is measured at different constant temperatures. The data acquisition module mainly includes a high voltage probe, a high-speed high voltage electrostatic voltmeter, a DAQ, and a computer.

The testing process is as follows: Place the sample on the ground electrode, maintaining a distance of 5mm between the grading mesh and the sample surface and between the grading mesh and the needle electrode. Adjust the required measurement temperature, and once the temperature is stable, begin pressurization by applying a DC voltage of -8kV to the needle electrode and -4kV to the grading mesh. The grading mesh ensures that the electric field generated by the corona uniformly acts on the sample surface and serves as the clamping voltage for potential decay. The corona charging time is 3 minutes. After charging, the sample is quickly and uniformly moved under the probe through the conveying track. The surface potential value is displayed by the high-speed high voltage electrostatic voltmeter and finally acquired through the DAQ and the LabVIEW program on the computer for 40 minutes. The humidity during the experiment is controlled below 30%.

Experimental Results:

The experimental setup was constructed, and the surface potential decay theory was introduced. Different temperature surface potential decay measurement devices and experimental conditions were also established.

High Voltage Amplifier Recommendation: ATA-7100

Figure: Specifications of the ATA-7100 High Voltage Amplifier

This material is compiled and released by Aigtek Antai Electronics. For more case studies and product details, please continue to follow us. Xi'an Aigtek Antai Electronics has become a widely recognized supplier of instruments and equipment with a broad product line and considerable scale in the industry. Sample machines are available for free trial.