Discover the importance of the dissipation factor in dielectric materials and explore the concept of tangent delta. Learn how insulating materials affect electrical devices and get to know the advanced solution, HVEX Tangent Delta, for precise measurements.
Insulators in Electrical Equipments:
In the context of electrical equipment, insulating materials do not have an active role in operations.
On the contrary, they often pose a challenge, as they occupy substantial space and increase volume and consequently, device costs. Moreover, they can hinder efficiency in heat dissipation.
However, it is worth noting that, although they may be perceived as an apparent inconvenience, the absence of these materials would result in the infeasibility of equipment operation.
Crucial Characteristics of Dielectric Materials in Electrical Applications:
The quality of insulating material is paramount in electrical applications, with a direct impact on safe and efficient system performance. Various characteristics define suitable insulating material for their respective purposes.
1. High Electrical Resistance and Stability
An essential characteristic is the material's high electrical resistance. This is crucial to restrict the flow of electrical current through the insulator, preventing short circuits and ensuring effective separation between energized conductors.
Additionally, it is crucial that the insulating material does not exhibit substantial variations in its physical and chemical properties over time, thus ensuring the stability of the electrical system.
2. Requirements in High Voltage Systems:
Specifically in high voltage systems, such as those found in power transmissions, additional requirements are imposed. The insulating material must be able to withstand the intense electrical fields to which it is subjected, without suffering damage.
In this context, it is crucial that the electric field does not cause electrical breakdown of the insulating material or trigger surface discharges. The analysis of characteristics such as surface resistivity, dielectric strength, dielectric constant, and dissipation factor plays an essential role in ensuring such performance.
3. Resistivity and Surface Resistance:
Electrical resistivity, expressed in ohm-meters, provides an indicator of its ability to hinder the flow of electrical charges. In general, the resistivity of insulating materials ranges from 10^6 Ω・m or higher, varying according to the material, its volume, and dimensions.
The higher the resistivity, the more effectively the material prevents the establishment of electrical currents. Another significant factor is the surface resistance of the insulating material, which is linked to the electrical current present on its surface. This characteristic, susceptible to moisture and pollution, can influence the occurrence of surface discharges, compromising the insulator's performance over time.
Losses in Dielectric Materials:
Dielectric materials are subject to losses that occur due to three main processes: conduction, polarization, and ionization. Each of these processes contributes to the dissipation of energy in the form of heat in the dielectric material.
Conduction: Even in the best insulators, there is a certain amount of electrical conductivity, albeit extremely low. When an electric field is applied to the dielectric material, electric charges can move through it, generating an electric current. This current generates internal resistance, resulting in losses in the form of heat. Conduction losses are most significant in materials with higher conductivity and are especially relevant in high-frequency applications.
Polarization: When a dielectric material is subjected to an electric field, its elementary dipoles align with that field. This process is known as dielectric polarization. The change in the orientation of molecules creates internal resistance to the movement of electric charges, resulting in the transformation of electrical energy into heat. This phenomenon is one of the main causes of losses in dielectric materials.
Ionization: Ionization occurs when the electric field applied to the material is so intense that it causes the breaking of bonds between atoms, resulting in the formation of positive and negative ions. This process generates an electric current that leads to the dissipation of energy in the form of heat. Ionization is more common in high-voltage applications, where electric fields are more intense.
Dissipation Factor: Tangent Delta
The Dissipation Factor (DF), also known as Loss Factor or Tangent Delta (tan δ), is a measure that describes the efficiency with which a dielectric material is able to store and release energy in an alternating electric field. In other words, it is a relationship between the energy lost in the form of heat and the energy stored in the material when subjected to an alternating electric field.
The dissipation factor is an important characteristic for assessing the insulation quality of a dielectric material. Ideal dielectric materials should store the energy applied in the electric field and release it back when the field is turned off, without dissipating energy in the form of heat. However, all dielectric materials have a portion of energy losses due to mechanisms such as resistance, dipole movement, conduction currents, and imperfections in the material.
A low value of Dissipation Factor indicates that the material is efficient in maintaining stored energy, meaning losses are minimal. On the other hand, a high dissipation factor value suggests that the material is losing a significant amount of energy in the form of heat during the alternating electric field cycle. This may be undesirable in many electrical applications, resulting in efficiency losses and potential overheating.
The Dissipation Factor is often used to assess the insulation quality of dielectric materials in electrical equipment such as transformers, capacitors, and cables, ensuring the efficiency and safety of these devices in operation.
HVEX Tangent Delta: Excellence in Dissipation Factor Measurement
Introducing HVEX Tangent Delta, the highlight of technology for dielectric dissipation factor (tan δ) and capacitance testing in electrical equipment.
High Precision for Confident Results
With digital waveform analysis and bridge auto-calibration, HVEX Tangent Delta provides extremely accurate measurements.
Safety and Confidence First
Instant response to short circuits and dielectric breakdowns ensures equipment integrity and test environment safety.
High Efficiency with Self-Excitation
Capacitance and dielectric loss are measured in a single test, optimizing your analysis process.
Comprehensive Solution with Support
HVEX Tangent Delta was developed with a focus on ease of installation and after-sales support, ensuring a smooth experience.
Benefits Driving Your Tests
– Anti-Interference Technology: Reliable results even in challenging environments.
– Multilevel Protection: Enhanced safety for your equipment and operators.
– Simplified Connectivity: RS232 port for test reports and firmware updates.
– Total Flexibility: Multiple working modes for a full range of tests.
– Connection Optimization: Built-in dielectric measurement modes, eliminating the need for extra equipment.
With HVEX Tangent Delta, HVEX offers a comprehensive and reliable solution for precise dissipation factor measurement, elevating the excellence of your electrical equipment. Experience the power of innovation with HVEX Tangent Delta and reach new levels of performance and reliability.
Click here and schedule a consultation with our team!