Transformer Parameter Variables

CHH Power adheres to strict industry norms and internal quality benchmarks when defining and applying technical parameters for its transformers and current transformers. These parameters directly determine product performance, reliability, and safety—serving as the foundation for CHH Power’s product design, testing, and customer-focused solutions. Below is a detailed breakdown of core parameters, aligned with CHH Power’s engineering practices.

For current transformers (CTs) produced by CHH Power, rated power is defined as a key performance parameter marked based on the device’s electrical characteristics under specified frequency and voltage conditions. This parameter indicates the maximum power the CT can reliably transmit to secondary-side measuring or protective devices without degrading accuracy. CHH Power ensures its CTs are labeled with rated power values tailored to different grid scenarios (e.g., industrial power distribution, grid metering) to guide proper selection and avoid overload-related errors.

Rated voltage refers to the designated voltage rating for a transformer’s windings, as standardized in CHH Power’s design specifications. A transformer operates continuously at this voltage while maintaining temperature rise within safe limits (compliant with IEC and national standards) and delivering output power that does not exceed its rated capacity. CHH Power’s engineering team verifies this parameter through long-duration load tests during production, ensuring transformers can sustain stable performance under rated voltage for their entire service life (typically 20+ years for standard models).

CHH Power defines the voltage ratio as the ratio of a transformer’s primary winding voltage to its secondary winding voltage. A critical technical note from CHH Power’s testing laboratory is that, for its transformers, there is no practical difference between the no-load voltage ratio (measured when the secondary is open-circuited) and the load voltage ratio (measured under rated load). This consistency is achieved through precise winding turn-count calibration during manufacturing, ensuring accurate voltage transformation across varying load conditions—essential for applications like grid voltage regulation and industrial power conversion.

The operating frequency is the specific frequency at which a transformer is designed and intended to operate, a parameter closely linked to core loss (iron loss) in CHH Power’s product development. Since core loss (including hysteresis and eddy current loss) varies significantly with frequency, CHH Power selects core materials (e.g., high-silicon silicon steel sheets for 50/60Hz, amorphous alloys for high-frequency applications) and optimizes core lamination thickness based on the target operating frequency. This ensures minimal energy dissipation and prolonged core lifespan, whether the transformer is used in standard 50Hz grid systems or specialized high-frequency power supplies.

Efficiency (often misstated as “speed” in non-technical contexts) is calculated by CHH Power as the percentage ratio of a transformer’s secondary output power (P2) to its primary input power (P1) (i.e., Efficiency = P2/P1 × 100%). A key trend observed in CHH Power’s product lineup is that efficiency tends to increase with the transformer’s rated power—larger units (e.g., 10MVA power transformers) typically achieve efficiencies exceeding 99%, while smaller distribution transformers (e.g., 500kVA) maintain efficiencies above 98.5%. This is attributed to optimized copper-iron ratios and advanced winding designs that reduce both copper loss and iron loss.

No-load loss (also called core loss at no load) is the power consumed by a transformer when its secondary winding is open-circuited and the primary is energized at rated voltage and frequency—measured as part of CHH Power’s routine quality testing. The primary component of no-load loss is core loss (from hysteresis and eddy currents in the iron core), with a smaller contribution from copper loss caused by the no-load current flowing through the primary winding’s resistance. CHH Power minimizes no-load loss by using low-loss grain-oriented silicon steel sheets and precision core assembly techniques, ensuring compliance with international energy efficiency standards (e.g., IEC 60076-11).

For CHH Power’s three-phase transformers, no-load current is the current drawn by the primary winding when the secondary is open-circuited. This current consists of two components: magnetizing current (responsible for generating the magnetic flux in the core) and iron loss current (caused by core loss). In the 50Hz current transformers commonly produced by CHH Power, the no-load current is predominantly composed of magnetizing current—typically accounting for 90% or more of the total no-load current—due to the low core loss of the selected magnetic materials.

Insulation resistance at CHH Power quantifies the insulating performance between a transformer’s windings, as well as between each winding and the iron core. This parameter is critical for preventing short circuits and ensuring operational safety. CHH Power’s testing data shows that insulation resistance is influenced by three key factors: the quality of insulating materials used (e.g., epoxy resin for dry-type transformers), operating temperature variations, and moisture levels in the environment. To maintain stable insulation resistance, CHH Power uses moisture-resistant insulating materials and conducts regular insulation resistance tests (using megohmmeters) during production and on-site maintenance.

Through rigorous definition, testing, and optimization of these technical parameters, CHH Power ensures its transformers and current transformers meet the high-performance and safety requirements of diverse power system applications.