To regulate the conditions of a grid fault, utility companies have developed regional grid code specifications that wind power plants must meet. These grid codes, which outline grid fault conditions and the expected wind turbine behavior in response to these conditions, are becoming more demanding, and vary from country to country. The wind turbine’s converter plays an important role in helping the wind turbine meet these requirements and obtain the necessary operational certification.
A common requirement for all grid codes is a fault ride-though capability, that is, the wind power plant and turbines must be capable of operating continuously at reduced voltage, and must not trip offline because of transient voltages.
To test its equipment against these grid codes, ABB developed a multi-megawatt fault ride-through laboratory. It is designed to replicate both doubly-fed and full converter turbines. The test equipment includes generators, converters, transformers, switchgear, and is connected to a 20 kV transmission line.
Laboratory engineers are able to test ABB products in a controlled and repeatable environment. Customized testing software is used to configure the test conditions, taken from individual grid code specifications. Tests can include multi-phase voltage dips, or even a sequence of faults progressing from single-phase earth faults to three-phase short circuits. This laboratory testing helps reduce onsite testing costs by replacing the variability of the wind with a speed-controlled motor that drives the generators.
Turbine certifications are based on the regional grid codes where the turbine will be installed. When turbine manufacturers are applying for turbine certification, ABB engineers can help them use and maximize the converter’s technology to meet the requirements of the local code.
ABB stays globally active in grid code working groups and standards definition to ensure ABB’s products continue to meet manufacturer’s needs.