Electrical Engineering

Service Technicians On Site

Be it examination of the marked-out routes, maintenance of transformer stations or the implementation of telecontrol – our team will support you in all matters of electrical engineering. Our experts will carry out DGUV (German Statutory Accident Insurance) inspections, will assume the systems operators’ tasks or will dismantle the cables.

Operations Management of Transmission Stations and Substations

Commissioning of a wind farm can only commence after startup of the cable lines. Prior to initial activation of the cable lines we check all documents (from the erection certificate through to VLF test) and appoint a person responsible for the plant. Authorized staff carry out the connections. Afterwards, operations management assumes responsibility for the transmission stations.

Takeover of Operational Activities

It is possible for our skilled electricians in charge to be appointed as system operators for your wind farm and/or for your transformer station, taking charge of all electrotechnical matters. After takeover, we are also the responsible contact for the energy supply companies (EVU) and we will review – for instance – necessary qualifications for switching operations, issue switching authorizations and supervise electronic operations.

Maintenance of Transmission and Transformer Stations

The maintenance team cleans and checks components, carries out functional tests, measures and checks the grounding system. If protection relays have been installed, these are checked and measured in accordance with protection records. When concluding servicing contracts, we assume plant responsibility in accordance with VDE 0105-100 and discuss any problems on equal terms with the grid operator.

DGUV Regulation 3 (formerly BGV-A3)

Each electrical system must be inspected at least every four years in accordance with DGUV Regulation 3. Our service teams can carry out this inspection and eliminate any defects identified.

Cable Tests and Diagnosis

As the first German operator we have our own cable test van. We execute all cable tests and diagnosis from the wind turbine generator to the transformer station directly on site. Cable routes requiring maintenance, sheath faults or faulty couplings can be detected immediately.

Equipped with Megger measuring technique, we conduct standardized VLF measurements (cosine square waves), cable fault prelocation and pinpointing, cable sheaths testing as well as partial discharge diagnosis with suspended alternating discharge (DAC). By use of the „50 Hz Slope Technology“ a direct comparison with the power frequency is possible. The operating software enables a „live“ PD mapping with direct evaluation. With a simple mouse click we are able to create a report directly after the measurement with a clearly structured summary of the most important data.

Besides the location of faults during the ongoing wind farm operation, we also use the cable test van for first commissioning according to DIN (German Institute for Norms) and in the scope of status-oriented inspections.

Corrective Actions

Cables and fittings as well are prone to aging or might be damaged by rocks, potentially leading to failure of the cable. It is for this reason that we recommend regular inspection of the lines.

In order to ensure fast troubleshooting, wpd windmanager has all common types of cable and fittings in stock. We are able to determine the position of the cable lines using our measuring devices and also draft up line plans. Furthermore, we will compile or review the documentation of line plans.

Repair and Replacement

If transformer damage occurs, we provide a loan transformer combined with dismantling and reassembly work to minimize yield losses. We can also carry out the repair (if possible), the procurement of new components or the disposal. Prior to every replacement of switching systems, we check and repair them, if applicable. Furthermore we offer the replacement including all necessary civil and cable work.

With regard to remote data monitoring, the manufacturer and service companies are usually only responsible for operation downstream of the “wind farm computer”. We can repair and replace all elements upstream of it. Specially trained staff and engineers are able to identify the degree of damage to the foundation of your turbines using our own measuring equipment and are capable to supervise the refurbishment. During the repair, downstream turbines can remain in operation utilizing our own mobile switching substations.

Installation of Telecontrol Engineering for Transmission Stations and Remote Meter Reading

Circuit breakers in transmission stations may trigger after, e.g. over- or undervoltage or frequency problems and the affected wind farm remains inoperative due to undervoltage. Normally, on-site service is then required. This can be avoided by installing telecontrol systems in the transmission stations whereby the protection relay can be read out remotely and the circuit breaker reconnected. Thereby yield losses can be reduced and travel costs do not apply. It is also possible to send alarms in spite of power outages to ensure the failure is identified quickly. All relevant data such as voltages, currents, frequency and trigger causes are recorded for a certain period. This ensures that the cause of the disturbance can be tracked prior to the triggering. Access control is integrated and a webcam may be connected as well.

Decommissioning (Repowering) and Dismantling of Cables

After the plants have been decommissioned on site, the final meter readings are recorded and the required decommissioning records are filled in. All cables and lines from the foundation and/or transformer station are removed and the cable lines dismantled.