Induced Voltage Test for Transformers

5 July 2023

The induced voltage test is a crucial test conducted to assess the insulation properties of transformer windings. This test involves subjecting the windings to excessive voltage to determine how resilient the insulation between the windings is when exposed to high voltage.

At Trans-El, we specialize in the reliability and quality of transformers. This test is an important step in verifying the compliance of our products with standards and the robustness of their insulation systems. As a result, we can provide our customers with high-quality and reliable transformers.

The test is carried out by applying excessive voltage to the transformer windings. This test is important for evaluating the durability of the insulation system between the windings and their capacity to withstand electrical stress. The voltage used during the test is a specific multiple of the rated voltage of the transformer and may have a frequency different from the rated frequency.

At Trans-El, we are equipped with advanced equipment and an expert team to conduct these tests properly. The accurate execution of these tests is critical to ensuring the safety and performance of transformers.

As Trans-El, we continually update and enhance our testing and quality control processes to provide our customers with high-quality and reliable transformers. This test is an integral part of these processes and plays a significant role in ensuring the durability and reliability of our products.

We understand the importance of this test in guaranteeing the reliability and performance of transformers. You can rely on us to perform the induced voltage test with meticulous care to deliver top-quality transformers in terms of reliability and performance.

Induced Voltage Test in Uniformly Insulated Windings

The induced voltage test is a vital testing method used to evaluate the insulation systems of transformer windings. This test assesses how resilient the insulation between the windings is when exposed to high voltage.

At Trans-El, we possess the necessary equipment and expertise to conduct this test. This test is a crucial step in verifying the quality and reliability of our transformers.

The test involves applying a three-phase voltage with a value twice the rated voltage of the low-voltage winding to the transformer. Meanwhile, the high-voltage phase terminals remain open. The applied voltage is sinusoidal and is typically set at a frequency different from the rated frequency and in multiples of the rated frequency (e.g., 150 Hz).

At Trans-El, we meticulously carry out this test. The test duration is calculated based on the relationship between the transformer’s rated frequency and the test frequency. This test allows us to reliably evaluate the insulation systems of our transformers and provide our customers with high-quality products.

As a company committed to reliability and quality, Trans-El considers this test a standard practice for all our transformers. We continuously review and improve our testing processes to provide our customers with robust and reliable transformers.

This test is one of the most critical quality control steps for us at Trans-El. It ensures the reliability and performance of our transformers. We always follow best practices to provide our customers with quality and reliable products, and we conduct the induced voltage test with great care.

Induced Voltage Test in Gradually Insulated Windings

The induced voltage test in transformers is a test method used to stress the insulation systems between windings by applying excessive voltage. This test is crucial for assessing the resilience and reliability of the transformer.

In the case of gradually insulated windings, this test employs a different approach. The test applies the test voltage sequentially to each phase, and the test voltage is determined based on the high-voltage level of the transformer. For example, for a transformer with a rated voltage of 154 kV, the test voltage is typically set at 275 kV according to standards. The test duration is calculated using the formula mentioned earlier and is generally set at 40 seconds in the test system.

The test voltage is measured using precise voltmeters or kV meters with the help of voltage measurement transformers or capacitive voltage dividers, with the high-voltage phase terminals left open. The test follows a connection scheme designed for YNyn-0 vector group and an insulated power transformer. The scheme illustrates the connection of the test voltage to the YG winding and the AG winding.

This test is a crucial method for effectively evaluating the insulation systems of transformer windings. It ensures the reliability and durability of the transformer. At Trans-El, we perform the gradual voltage test in strict compliance with high-quality standards to provide our customers with reliable transformers.

Evaluate Insulation Reliability with the Induced Voltage Test

The induced voltage test is an essential test method to assess the reliability and durability of the insulation systems of transformers. This test is conducted by subjecting the windings, which form the coils, to high voltages to evaluate how well the insulation withstands extreme electrical stress. The purpose of this test is to ensure that transformers operate reliably and effectively over the long term.

The methods of applying this test can vary depending on the structure of the transformer and its insulation system. Initially, the test is performed on transformers with uniformly insulated windings, where a three-phase voltage with a value twice the rated voltage of the low-voltage winding is applied. The voltage used during the test is sinusoidal and often differs from the rated frequency, being multiples of the rated frequency (e.g., 150 Hz).

For transformers with gradually insulated windings, a different approach is used. In this case, the test voltage is applied sequentially to each phase, with the test voltage determined based on the high-voltage level of the transformer. The test duration is calculated based on the relationship between the transformer’s rated frequency and the test frequency.

At Trans-El, we understand the critical importance of this test in assessing the reliability and performance of transformers. We perform these tests with precision and care to ensure the safety and longevity of our products. These tests play a significant role in the production of transformers that meet reliability and quality standards in the energy sector.

To learn more about the induced voltage test, please visit the official Trans-El website.