Hydrogen rectifiers

Overview

What it does

Statcon Energiaa designs, builds, tests and services high-current rectifiers that turn grid or renewable AC into the clean, steady DC an electrolyser stack needs. Units start at 250 kW and blocks run to 15 MW, for alkaline and PEM stacks, fed from the grid or directly from solar and wind.

The rectifier converts three-phase AC into regulated DC. As the stack ages its voltage rises from beginning to end of life, so the rectifier holds the current steady across that whole window, while keeping ripple, harmonics and power factor within limits. Our scope is the rectifier, its controls and the stack interface; the converter transformer is optional from us.

IGBT chopper rectifier

DC-3 technology from AEG PS, Germany, built, warranted and serviced in India by Statcon Energiaa under a technology licence. A bridge at fixed voltage feeds an IGBT chopper that regulates stack current at 3.2 kHz, which gives high power factor and low harmonics without extra filters and a fast response that follows solar and wind. Modules of 3,200 A run up to eight in parallel with n+x redundancy. Best suited to renewable-coupled, MW-scale plants.

Full load type test of the DC-3 V3.3 platform, May 2026: 6.5 MVA, 13,000 A at 450 V on a 30 kV grid, in 12 pulse configuration without filters. Power factor 0.95 to 0.96, system efficiency about 97.6% including transformer and AC cable, current THD 4.8% at full load, DC current ripple 0.2% RMS. Values are typical; binding guarantees are given in the project datasheet.

SCR (thyristor) rectifier

Our own 6, 12 and 24 pulse thyristor technology, proven in defence since 2010. Phase angle control makes it rugged, simple and easy to maintain, with up to 10 kA and 1,200 V DC from a single engineered unit, forced air cooled and rated for 50 °C outdoors. Available as indoor panels, outdoor containers or trolley-mounted units. Best suited to grid-fed plants and very high currents.

Track record

About 100 MW of green hydrogen rectifiers are in execution, India’s first order at this scale, built on IGBT chopper technology. More than 350 MW of DC-3 platform rectifiers are installed worldwide, including 100 MW for green steel in Germany, 60 MW for mobility in Germany, 16 MW for a base-load power plant in French Guiana and a 2.5 MW hydrogen mobility skid in France. Sixty MW of thyristor rectifiers have been supplied for defence since 2010. Rectifiers are built and tested at our Pilkhuwa works, which is ISO 9001, 14001 and 45001 certified.

Why engineers choose it

• Holds stack current steady from beginning to end of life
• Power factor 0.95 or better at MV input, 30 to 100% load, on the IGBT chopper
• Current THD below 3% at 24 pulse, without extra filters
• Peak efficiency up to 98.5%, excluding transformer
• Up to eight modules in parallel with n+x redundancy
• Fast response that follows solar and wind
• Built, tested, warranted and serviced in India
• HMI with Modbus, PROFINET and 4 to 20 mA