Ensuring the safe and stable operation of equipment is of paramount importance in the power system. For many high-voltage electrical equipment, such as transformers, mutual inductors, etc., in addition to paying attention to their insulation performance, we also need to understand a key parameter - dielectric loss. What is the purpose of the high-voltage dielectric loss testing device? Why is it so important? Today we will talk about this topic.

What is high voltage dielectric loss?

Simply put, dielectric loss refers to the energy loss inside the dielectric under the action of an electric field. This energy will be converted into thermal energy, which may cause equipment overheating, accelerate insulation aging, and even lead to breakdown accidents in the long run. The dielectric loss coefficient (usually represented by tan δ) is an indicator of the magnitude of this energy loss. In the insulation diagnosis of high-voltage electrical equipment, tan δ is a very important reference value.

What are the factors that affect dielectric loss?

The reasons for the increase in dielectric loss are multifaceted, mainly including:

Aging and deterioration of insulation materials: Over time, the molecular structure of insulation materials will change, leading to an increase in dielectric constant and loss factor.

Moisture intrusion: Moisture in insulation materials significantly increases their conductivity, thereby significantly increasing dielectric loss.

Impurities mixed in: Impurities present in insulation materials, especially conductive impurities, can form conductive pathways and increase losses.

Temperature variation: The dielectric loss of most insulation materials increases with the rise of temperature.

Partial discharge: Small discharges inside insulation can generate electrochemical reactions, producing conductive substances and increasing losses.

What tools can help us with testing?

In order to accurately measure the high-voltage dielectric loss equipment, we need a professional dielectric loss tester. This is an instrument that can generate high voltage and accurately measure loss parameters. As a senior enterprise in the power industry, Wuhan UHV Power Technology Co., Ltd. has developed a high-voltage dielectric loss testing device that can provide us with reliable test results. These types of devices typically have high integration, are easy to operate, and can adapt to different on-site testing environments.

What are the fields related to dielectric loss testing?

Dielectric loss testing is closely related to the following fields:

Insulation diagnosis of power equipment: This is the most direct application used to evaluate the insulation health of high-voltage equipment such as transformers, cables, transformers, and bushings.

Equipment status monitoring: By regularly conducting dielectric loss tests, insulation hazards can be detected in a timely manner to avoid sudden failures.

Equipment factory acceptance: As a quality inspection method for new equipment, it ensures that its insulation performance meets the design requirements.

High voltage test: Dielectric loss testing is an essential part of various high-voltage tests conducted in the power system.

How can we do better?

To conduct a good high-voltage dielectric loss test, the following points should be noted:

Choose the appropriate test voltage: According to the equipment regulations and actual situation, select the appropriate test voltage for measurement.

Ensure a clean and dry testing environment: Avoid external interference such as dust, moisture, etc., which can affect testing accuracy.

Standardized wiring operation: Ensure that the wiring of the tester is correct and secure, and prevent short circuits or poor contacts.

Understand reference values and trends: Understand the reference values of dielectric loss for similar equipment under normal conditions, and pay attention to their trends over time to determine the equipment status.

Combining other diagnostic methods: Dielectric loss testing is not an isolated diagnostic method, and can be combined with other insulation resistance testing, partial discharge detection, and other methods for comprehensive analysis to obtain more accurate conclusions.

The professional equipment provided by Wuhan UHV Power Technology Co., Ltd. provides us with a solid guarantee for accurate and reliable dielectric loss testing. Proper use of high-voltage dielectric loss testing equipment can effectively improve the operational safety and reliability of power equipment.

FAQ

Q: Does a high dielectric loss value necessarily mean that the equipment is broken? Answer: Not necessarily. Although high values are usually abnormal signals, factors such as temperature and humidity can also affect the test results. It is important to make a comprehensive judgment based on historical data and equipment operation status.

Q: Is the normal range of dielectric loss the same for different types of high-voltage equipment? Answer: It's different. Different types of equipment (such as transformers, cables, and transformers) have different insulation materials, structures, and working environments, so the normal dielectric loss values will also vary. Please refer to the manufacturer's instructions or industry standards.

Q: Can I conduct a dielectric loss test in a humid environment? Answer: Strongly not recommended. A humid environment can seriously affect the accuracy of testing, potentially leading to high readings and incorrect judgments. Before testing, the environment should be kept as dry as possible.

Q: Apart from tan δ, are there any other indicators for measuring dielectric loss? Answer: tan δ (loss tangent) is the most commonly used indicator. In some cases, the change in capacitance value (C) is also taken into account, which, together with tan δ, can more comprehensively reflect the insulation state.

Q: Is there anything special about the operation of the equipment at Wuhan UHV Power Technology Co., Ltd? Answer: The equipment of Wuhan UHV Power Technology Co., Ltd. usually focuses on user experience, adopts a user-friendly interface and intelligent testing process, and strives to enable on-site operators to complete testing tasks more conveniently and accurately. For specific device functions and operational details, it is recommended to refer to their official website or product manual.