An app note from Bourns on their high voltage isolation magnetics to monitor large energy storages. Link here (PDF)
Energy storage systems are emerging as one of the potential solutions to increase system flexibility due to their unique capability to quickly absorb, hold and then reinject electricity. Over the last few years, DC voltages in energy storage systems have continued to advance higher using lithium-ion battery technology. Today, 250 VDC, 600 VDC, 1000 VDC and now even 1500 VDC are employed.
One of the key drivers of these higher-voltage systems is the availability of advanced solar inverters and power converters. Considering that most utility-scale battery energy storage systems are now being deployed alongside utility scale solar installations, it makes sense that the battery systems match the input DC voltages of the inverters and converters. Most utilityscale solar inverters and converters now use 1500 VDC input from solar panels.
This application note covers the higher voltages, features and capabilities required for magnetic components to connect various sources of energy to an electricity grid that uses battery storage in order to maximize efficiencies. It also provides the insulation requirements designers should be aware of in specifying transformers rated to 1500 V.