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World's Most Powerful Test System for Mega Wind Turbines in Operation

Wilhelmshaven, Germany - When powerful wind turbines and large wind farms are to be connected to the medium-voltage grid, extensive tests are necessary. For example, the behaviour and handling of a wind turbine with externally occurring disturbances in the power grid are tested.

EESYST GmbH has now developed and launched a new, mobile testing device for wind turbines in the medium-voltage grid. The first test device was delivered to the certification company Underwriters Laboratories (UL) and put into operation. With a testable capacity of up to 30 MVA at voltages up to 36 kV, and under restrictions also up to 40.5 kV, EESYST Energie Elektrische Systemtechnik GmbH can measure the largest wind turbines and possibly also wind farms on site. The new grid connection rules and the increasingly larger turbines make this setup necessary, the company announced.

On-site grid simulations and wind turbine assessment

In addition to the usual standards according to FGW TR3 and IEC 61400-21, many special tests can be carried out that are helpful for the evaluation of the wind turbines. These include phase jumps, which can also be conditionally interpreted as frequency jumps, or a variety of asymmetrical faults. This is possible even though the system is passive, i.e. without a costly and sensitive frequency converter. Due to the highly accurate sensor technology, which clearly exceeds the standard, compensation effects can be observed with the network, which basically justifies a free-field test.

Certification company UL orders first test system from EESYST

The US company UL-Underwriters Laboratories was the first to order a test system. Commissioning took place in March 2021, and since then extensive FRT (Fault-Ride-Through) tests have already been carried out on a plant from the power class above 10 MW.

" We are very happy that we were able to provide a super-compact test system within 7 months", says Rainer Klosse, Managing Director of EESYST. “The overall structure fits into an ISO container, so that the initial commissioning could be reduced to one working week until the first test. We were immediately able to carry out tests under load of up to 140% overvoltage and have still not reached the limits of the test facility. The actual operation has also been completely ergonomically revised so that more than the otherwise usual 2 configurations can be set at the same time and entering the high voltage zone is accelerated without loss of safety is realized by various functions."

About EESYT Energie Elektrische Systemtechnik GmbH

EESYST Energie Elektrische Systemtechnik GmbH was founded in 2019. The company calculates and simulates the electrical grid connection of generation plants. With the mobile test system that has now been delivered, manufacturers or certification bodies, for example, can prove directly on site that their wind turbines can withstand dynamic grid disturbances at the medium-voltage level and also formally meet the specifications of national and international grid connection rules.

Source: IWR Online, 02 Jun 2021