Electrical tests play a vital role, allowing for thorough evaluation of electrical equipment to identify potential faults, ensure proper functioning, and ensure compliance with applicable technical standards and regulations.
What are Electrical Tests?
Electrical tests are technical and scientific procedures in which voltages, currents, and other electrical stimuli are applied to electrical equipment and systems to evaluate their performance, functionality, safety, and quality. These tests are conducted at various stages of the equipment lifecycle, from design and manufacturing to installation, operation, and maintenance.
Conducting electrical tests is of utmost importance to ensure the quality and safety of electrical equipment. These tests allow for verification of whether the equipment meets the established technical and regulatory requirements, as well as identifying possible design flaws, manufacturing defects, or deterioration over time.
Types of Electrical Tests Conducted by HVEX
1. Radio Interference Voltage (RIV) Test:
The RIV (Radio Interference Voltage) test, or radio interference voltage, is a procedure used to evaluate equipment's susceptibility to electromagnetic interference, especially radio frequency. During the test, the equipment is exposed to different radio frequency signals, simulating real conditions in which it will be used.
RIV voltage is measured to assess how the equipment responds to these interferences. The obtained results are compared with the limits established by applicable standards and regulations to determine if the equipment is compliant. If not, corrective measures are taken to minimize interference.
HVEX Solution: HVEX has developed an RIV measurement test system according to current standards, especially for glass or porcelain pin or pedestal insulators. Our solution is offered in two main options, depending on customer preferences. The first option consists of a set of three units: the control station, which allows the operator to activate, control, and supervise the tests through a computer and control panel; the power panel, where protection devices, inverters, and PLCs are located; and the container, which houses all the testing equipment and measurement system. This compact solution provides precise and reliable evaluation of the RIV of electrical equipment.
2. Routine Testing on Transformers
Routine tests are conducted to verify the full operation of all devices constituting electrical systems. They are performed on all equipment or a significant sample from a batch. These tests may be required by the buyer before completing the purchase or by the manufacturer for every batch produced; they are also responsible for verifying the quality and uniformity of the production process and materials used in equipment manufacturing.
HVEX Solution: HVEX offers a solution covering a variety of routine tests on high-power transformers. These tests include winding resistance measurement, transformation ratio, polarity, angular displacement, phase sequence, short-circuit impedance measurement, load loss, no-load loss, excitation current, routine dielectric tests, on-load tap changer tests (when applicable), and insulation resistance measurement.
HVEX's solution allows these tests to be conducted on Single-phase Power Transformers with a nominal power of up to 1kVA and Three-phase Power Transformers with a nominal power of up to 5 kVA. Additionally, it covers instrument transformers, static converters, and traction transformers mounted on rolling components, starting transformers, testing transformers, and welding transformers. Measurement results are provided in CSV format, allowing for customized analyses. In the next chapter, we will emphasize no-load and load loss tests, as they play a fundamental role in ensuring transformer operating conditions and confirming their operating parameters indicated on the nameplate, ensuring their reliability.
3. Temperature Rise Test
The working temperature is crucial for the proper performance of transformers, as the viscosity of insulating oil varies with temperature. Temperature rise also affects the dielectric properties of insulation materials, which can lead to areas more susceptible to partial discharges inside the equipment.
HVEX Solution: HVEX's solution for this challenge is the Routine Test and Temperature Rise Testing Panel, applicable to both three-phase and single-phase transformers, conducting tests in this category of transformers, including special transformers. Additionally, another offered solution is the thermal cycle, allowing testing and analyzing the temperature profile of equipment such as load break switches during operation under load.
4. Rapid Testing Laboratory
Routine tests are aimed at verifying the quality and uniformity of the production process and materials used in the manufacture of equipment that will help compose and operate in the grid. These tests, in greater detail, are performed on all equipment in a batch, or on a significant sample representing it, and are usually required by the buyer before completing the purchase. Therefore, their importance lies in verifying, immediately after the end of the production process of certain equipment, compliance with project specifications, normative standards, and product quality, theoretically ready to be part of the electrical system.
HVEX Solution: HVEX's rapid testing laboratory comprises a multi-test platform developed to automate and optimize the production line flow of distribution transformers. Through a single platform, integrated by the container testing module and the portable OHMVEX meter, HVEX's solution enables rapid and safe execution of all routine electrical tests required by standard NBR 5356-1 for transformers with a voltage class up to 36 kV and power between 5kVA and 300 kVA, as well as temperature rise tests and saturation curve.
5. Transformer Turn Ratio (TTR)
The transformer turn ratio test, also known as the transformer turn ratio test, is performed through a specific method aimed at providing or confirming the transformation ratio of a transformer.
This method uses a reference transformer with a variable ratio, which allows checking not only the transformation ratio of the transformer under test but also the correct operation of windings, including possible short-circuited turns, on-load tap changer failures, and incorrect tap connections. The equipment used to perform the TTR test is called TTR and has an interface that provides the previously mentioned errors.
HVEX Solution: HVEX's TTR module (Ohmmeter + TTR) constitutes a portable and robust case that checks, in addition to the transformation ratio, the angular displacement of the transformers under test. It offers high accuracy, protection by fuses and varistors, automatic control, and the possibility of providing connection diagrams in the control software for TTR tests, Ethernet interface. Additionally, for resistance measurement, the equipment allows operation with controlled ramps.
6. Electrical Tracking
The electrical tracking test evaluates the surface resistance of insulating materials under severe environmental conditions. These conditions are simulated by using contaminating liquid and positioning the test specimens on an inclined plane.
Although the test accelerates wear effects on insulation materials, it does not accurately reproduce all conditions encountered in real operation. To ensure the validity of the tests and the materials ability to withstand operational demands, it is necessary to follow the standards that standardize the conditions imposed on equipment during tests.
HVEX Solution: HVEX's solution specifically conducts the electrical tracking test according to NBR 10296 and generates an automatic report with the test result. The figure below, in turn, presents the structure of the equipment used for this type of HVEX test.
HVEX also provides software that allows automated execution of the electrical tracking resistance test, as well as storage of data about clients, manufacturers, test specimens, and all other equipment comprising the testing structure. Through HVEX Tracking, all aspects related to the mentioned test can be parameterized, controlled, and recorded. Additionally, the software can display certain important quantities in the test in graphs, assess if they comply with normative specifications, and, after completing the test, issue a technical report with the collected results and rapid stabilization response.
Electrical Tests and Product Quality Assurance
Electrical tests play a fundamental role in certifying the quality assurance of electrical products. They are conducted to verify if electrical equipment complies with technical specifications, standards, and regulations. By conducting these tests, it's possible to assess the performance, functionality, and safety of the products, ensuring they meet established requirements and provide reliable and safe operation.
Steps for Conducting Electrical Tests:
Preparation
Before starting electrical tests, proper preparation is essential. This may include checking the safety conditions of the place, visually inspecting the equipment will be tested, preparing measurement instruments, and defining test parameters, such as the voltage or current to be applied.
Connections and Configurations
The equipment is connected according to test specifications. This may involve connecting test cables, connecting to power sources or signal generators, and configuring measurement instruments to record relevant electrical quantities during the test.
Application of Voltage or Current
With connections established and configurations made, the appropriate electrical voltage or current is applied to the equipment being tested. This can be done gradually, allowing observation of the equipment's responses at different voltage or current levels.
Monitoring and Measurement
During the test, it's essential to monitor and measure relevant electrical quantities to obtain precise and meaningful data. This may include measuring resistance, current, voltage, frequency, among other electrical quantities, depending on the type of test being conducted.
Evaluation of Results
After completing the test, the results are analyzed and evaluated. This may involve comparing measured values with acceptance criteria established by technical standards and regulations. Results can also be compared with previous tests to identify variations and trends over time.
Report Generation
Finally, a report containing the results of the electrical tests is generated. This report describes in detail the procedures performed, the equipment tested, the measurements taken, and the results obtained. The report may provide recommendations if any non-conformities or corrective maintenance needs are identified.
In conclusion, electrical tests play an essential role in ensuring the quality, reliability, and safety of electrical equipment. These tests allow assessment of equipment performance, functionality, and compliance with technical standards and regulations.
By conducting electrical tests, it's possible to identify potential design flaws, manufacturing defects, and deterioration over time, contributing to preventing electrical accidents, power supply interruptions, and equipment damage.
Enhance the Quality of Your Electrical Equipment with HVEX!
HVEX offers a variety of solutions for different types of electrical tests, ranging from radio interference voltage tests to routine tests on transformers, temperature rise tests, electrical tracking, and transformer turn ratio tests. These solutions are designed to provide accurate and reliable evaluation of electrical equipment, ensuring their compliance and offering detailed results through technical reports.
Discover the potential of electrical tests with HVEX!