The first smart transformer pilot installed in our Ormazabal Transformer Division

The first smart transformer pilot was installed in our Ormazabal Transformer Division (January 2017), one of Ormazabal’s industrial facilities (Loeches, Madrid) to maintain stable voltage and assess the CVR (Conservation Voltage Reduction) strategy taking into account photovoltaic generation and reactive compensation. The objective of the CVR strategy is to achieve a significant reduction in peak consumption at no cost through load shedding.

CVR strategy and transform.smart   Features: 15 / 0.42 kV, 630 kVA; 9 taps ±4% Step voltage 1% Reactive power compensator: 175mVar SPV plant: 263.34 kW

The test results show a clear dependence between the values ​​of the voltage and power: active and reactive.

As an example, we show two figures where it can be observed that, by reducing the voltage, we can reduce the consumed power.

Ormazabal solution and challenge:

The CVR strategy facilitates the reduction of peak consumption and contributes to energy savings by decreasing the voltage magnitudes to the minimum permitted limits without affecting the performance of the end devices. The reduction in energy demand depends on the types of connected loads. The CVR strategy is most effective with constant current or constant impedance loads, cases in which a reduction in voltage results in a reduction in power. Furthermore, losses could be reduced for constant impedance loads due to the reduction in current. The results of the factory tests confirmed the existence of a relationship between voltage changes and active/reactive power reduction.

Main benefits for the customer:

• In most cases (more than 50% of the values), applying the CVR strategy using two transforma.smart tap changes (1% each) provides power savings of more than 1.5%.
• It was observed that each tap change makes it possible to implicitly describe the type of downstream load.