Power Conversion Solutions

Power conversion is the process of converting electrical energy from one form to another — AC to DC, DC to AC, or one voltage level to another — so that power from a source (a solar array, a battery, the grid) can be used by a load or fed into an electrical network. In utility-scale applications, power converters are the critical interface between generation assets, storage systems and the grid. Hitachi Energy designs, builds and commissions power conversion systems for battery energy storage (BESS), utility-scale solar PV and hybrid solar-plus-storage plants.

A bidirectional power electronics device that converts DC power from a battery into AC power for injection into the grid, and AC power from the grid into DC power for battery charging. In a utility-scale BESS, the PCS is the critical interface between the battery bank and the grid connection point. It controls charge and discharge rates, manages voltage and frequency response, and ensures grid code compliance. Hitachi Energy’s PCS is rated for battery voltages up to 1,500 VDC and is built on a liquid-cooled platform for performance in harsh environments.

Both are built on Hitachi Energy’s common liquid-cooled platform but serve different plant configurations. PCS is for standalone BESS. PVI is a complete photovoltaic inverter station for standalone utility-scale solar PV. They can also be used for AC or DC-coupled hybrid solutions integrating both solar PV and battery storage into a single grid connection point. All controlled by the Power Plant Controller (PPC).

In a DC-coupled plant, the solar panels and battery share a single DC bus and a single power conversion stage to the AC grid. This avoids the additional energy loss of an AC-DC-AC conversion step in AC-coupled designs. 

Primary and secondary frequency response, synthetic inertia, voltage regulation, reactive power support, ramp rate control and energy shifting. The fast dynamic response of the PCS — with millisecond-level active power control — enables participation in ancillary service markets and system integrity protection schemes (SIPS), as demonstrated at the Waratah Super Battery in New South Wales.

PPC is Hitachi Energy’s supervisory control platform for renewable and storage power plants. It sits between the operator’s SCADA system and the power conversion devices, managing dispatch, grid code compliance, state-of-charge optimisation and fault management. PPC integrates directly with the battery management system (BMS) from leading battery manufacturers, reducing project complexity and commissioning time.

The liquid-cooled platform eliminates forced-air ventilation, reducing dust ingress. Internal components carry protective coatings for resistance to saline corrosion. The system maintains rated performance at high ambient temperatures and altitudes. 

Primarily utility-scale BESS, solar PV and hybrid solar-plus-storage plants. Additional applications include power conversion for green hydrogen electrolysis, large industrial energy storage, data centre power management and grid-to-rack solutions, and onshore or offshore wind grid connection. Used by project developers, independent power producers, utilities, grid operators and system integrators.