Kehua has announced that its SPI series 1500V/350kW string inverter has passed High Voltage Ride Through (HVRT) and Low (zero) Voltage Ride Through (LVRT) testing.
Requirements for HVRT and LVRT certification are extremely challenging.
In terms of dynamic reactive power support, when high and low penetration of parallel network voltage occurs, the test requires the inverter to issue the target reactive current within 60ms, the overshoot should be less than 20%, the regulation time should be less than 150ms, and the control error should not exceed 5% of rated current.
For active power control, inverter output active power should remain unchanged when the parallel network voltage is high throughout; after the parallel network voltage is low through recovery, active power should be recovered at 30% of rated power per second.
When considering reactive power limitation, the maximum effective value of dynamic reactive current should not exceed 1.05 times the rated current when the inverter has three symmetrical high and low wear faults of reactive current; the maximum effective value of dynamic reactive current should not exceed 0.4 times the rated current when asymmetrical faults occur.
Test data shows that Kehua’s 1500V/350kW inverter has strong fault ride-through capabilities.
When a high or low pass-through fault occurs in the AC voltage measurement of the inverter, such as three-phase or single-phase asymmetry, the inverter can generate power without interruption and quickly send reactive current to support the grid, increasing its stability. When the high and low pass-through faults are over, the inverter quickly restores power generation to pre-fault levels to ensure maximum revenue.
Kehua is one of the first companies to develop and market high power string inverters. Its 1500V/350kW inverter is currently the largest string inverter in the world in terms of single power. Since its launch in June 2021, it has become extremely popular with customers and has been successful in over 2GW of bids.
The inverter also takes into account overall ventilation, heat dissipation, anti-corrosion and dustproofing factors, adopting a high protection level design, which can adapt to various harsh natural environments with high efficiency, high protection and high reliability.
The product is also equipped with fault recording, key device life prediction and intelligent online upgrade functions to enable the combination of intelligent power plant operation and maintenance management with cost reduction and efficiency. In addition, the inverter has an optional reserved energy storage interface to reduce the cost of adding storage at a later stage.