Among the various tests outlined in the IEC 62271-202 standard, the temperature-rise test is undoubtedly a critical assessment for validating the performance of prefabricated MV/LV substation architectures.
The thermal design of substations typically employs one of two methodologies:
Practical, for instance, through iterative trials,
Measurements and correction calculations for buildings often rely on analytical formulas where numerous heat-transfer coefficients are set arbitrarily, leading to substantial variations in the outcomes.
The thermal numerical calculation method considers all thermal phenomena within a substation, along with its architecture, which encompasses multiple systems including the LV switchboard, the MV switchboard, and the transformer.
Thermal modelling of these systems can enable the optimization of the substation, allowing the model to accommodate a wide range of configurations by adjusting its various parameters.
Type Tests
In type testing, manufacturers must evaluate the most extreme configuration or demonstrate the severity level to the certifying authority. This allows them to assert that the test encompasses a full range. Customers frequently request that existing substation proposals be modified to comply with their specific local needs.
Changes in power, architecture, or design frequently affect the thermal performance of a substation.
The new configuration is rarely revalidated through testing. Typically, the thermal performance of the new design is extrapolated from an already-tested base configuration using empirical formulas.
Document: | Thermal Design of MV/LV Substations by Schneider Electric |
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Size: | 523 kB |
Pages: | 5 |
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