In African power distribution projects, transformers may need to operate with different medium-voltage networks due to grid expansion, regional voltage differences or future system upgrades. A dual high-voltage transformer provides a practical solution by allowing two specified high-voltage levels to share one transformer while maintaining a stable low-voltage output.
Where Are Dual High-Voltage Transformers Used?
Demand is particularly relevant in Africa's utility distribution, industrial parks, mining projects, commercial facilities and rural electrification programs. Markets such as Burundi, Zambia, Nigeria, Cameroon, Mozambique and the Democratic Republic of Congo may involve projects where flexible medium-voltage adaptation is an important consideration.
Typical configurations include 30/10-0.4kV, 20/11-0.4kV and other customer-specified voltage combinations. For example, New Electric Power recently delivered 8 dual-high-voltage oil-immersed transformers in Burundi, including 1000kVA and 2000kVA units with a 30/10-0.4kV configuration.
How Does a Dual High-Voltage Transformer Work?
Unlike a conventional transformer designed for one fixed primary voltage, a dual-high-voltage transformer incorporates a specially designed high-voltage winding structure and switching arrangement to accommodate two specified voltage levels.
The two high-voltage ratings must be considered during electromagnetic design, insulation coordination, winding arrangement, tap selection and short-circuit calculation. The transformer is therefore not simply a standard transformer with an additional voltage marking.
New Electric Power Engineering Capability
New Electric Power designs customized oil-immersed transformers according to the actual grid and project requirements. Our engineering process can consider:
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Dual high-voltage winding configuration
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Rated capacity and voltage ratio
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Frequency and insulation level
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Vector group and neutral arrangement
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Impedance and short-circuit requirements
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Tap changer configuration
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Cooling and temperature-rise requirements
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Outdoor installation and environmental conditions
For African applications, the design can also consider high ambient temperature, outdoor operation, dust, humidity and unstable grid conditions when specified by the project.
How Should Buyers Select a Dual-High-Voltage Transformer?
Before requesting a quotation, buyers should provide the two required high-voltage levels, low-voltage output, capacity, frequency, installation environment and applicable standard. For utility or EPC projects, the grid fault level, insulation requirements, connection group and tap range should also be confirmed.
For example, a project requiring 30/10-0.4kV, 2000kVA, 50Hz should not be quoted only by capacity and voltage. The supplier should first verify whether the two HV levels are required for alternative operation, network compatibility or another specific switching arrangement.
With transformer engineering, manufacturing, testing and export experience, New Electric Power provides customized solutions for distributors, EPC contractors, utilities, mining companies and industrial power projects.
Need a dual-high-voltage transformer for an African distribution project? Send us your two HV voltages, LV voltage, capacity and application. Our engineering team can evaluate the configuration and provide a customized technical solution and quotation.
