In the maintenance, testing, and guarantee of modern power systems, the triple frequency induction withstand voltage test device plays a crucial role as a key equipment. This article will provide a detailed technical analysis of a triple frequency induction withstand voltage test device produced by Jiangsu Jiuyi Electric Power Equipment Co., Ltd. to help readers gain a deeper understanding of the device's performance, working principle, and application scenarios.

1、 Product Overview

The triple frequency induction withstand voltage test device is a lightweight testing equipment made by utilizing the saturation characteristics of the magnetization curve of silicon steel sheet iron core in the power grid, and inducing the zero sequence third harmonic potential through the secondary coil connected into an open triangle by a transformer. This device can not only meet the needs of small capacity power transformers and series high voltage transformers for frequency doubling induction high voltage testing in power systems, power plants, substations, and power distribution networks, but also be used for frequency doubling high voltage testing of various low-voltage electronic, instrument power transformers, and inductor coils. At the same time, it can also be used as a frequency doubling power supply with a power not exceeding 1 kW, for the power supply or testing of certain special electrical equipment.

2、 Working principle

The working principle of this device is based on the structure of three single-phase transformers, with the primary side connected in a star shape and the secondary side connected in an open triangle shape. When a symmetrical three-phase sine wave power supply is added to the primary side and the voltage is increased to saturate the magnetic circuit of the iron core, the third harmonic components contained in the magnetic flux in the iron core will increase, thereby inducing the third harmonic voltage on the iron core coil. The 150 Hz (three times the power frequency) induced voltage output from the secondary side of the open triangle generator is used as the triple frequency test power supply voltage.

When the third harmonic generator is loaded (such as JCC-220 high-voltage series voltage transformer), its current changes from inductive to capacitive. Due to the low power factor, the efficiency of the generator is relatively low, usually only about 20%. Therefore, in order to improve the power factor of the entire test circuit, a reactor can be connected to a certain empty winding of the test sample for current compensation.

3、 Technical parameters and usage methods

The triple frequency induction withstand voltage test device has multiple technical parameters, such as insulation resistance inspection before use (not less than 0.5M Ω), firmness inspection of joints at each connection, and contact condition of the voltage regulator carbon brush. When using, the following steps should be followed:

1. Connect the working circuit according to the principle, and ensure that the generator casing, control box casing, and common ground wire are well grounded to ensure the safety of personnel and equipment.

2. Set the operating values of the current regulator and timing alarm based on the current level and withstand time required for the normal induction withstand voltage of the test sample.

3. After checking that the circuit is correct, connect the test line and turn on the power to the control panel (box).

4. Press the start button and the green indicator light will turn on. Slowly rotate the voltage regulator handle clockwise to gradually increase the voltage, and pay close attention to the indication on the voltmeter and the condition of the test sample.

5. Set the timer timing as needed to complete the product's withstand voltage test within the specified time. After the experiment is completed, return the regulator handle to zero, press the stop button, and cut off the main power switch.

4、 Precautions and maintenance suggestions

When using a triple frequency induction withstand voltage test device, the following points should be noted:

When opening the box, the integrity of the equipment and the insulation of the main circuit and control circuit should be checked.

2. Before use, ensure that all connections are firm, especially the contact of the regulator carbon brush should be good.

When not in use for a long time, the equipment should be stored in a dry, non corrosive gas environment to extend its service life.

In addition, in order to maintain the good performance of the equipment, it is recommended to perform regular maintenance, such as cleaning the surface of the equipment and checking the connection of each component.

V. Summary

The triple frequency induction withstand voltage test device, as an important tool for power system testing, has broad application prospects and market demand. This article provides a detailed introduction to the performance characteristics, working principle, technical parameters, usage methods, and precautions of the device, aiming to help readers better understand and use the device. In the future maintenance, testing, and guarantee work of the power system, the triple frequency induction withstand voltage test device will continue to play its irreplaceable role.