The conference proceedings of the 4th Conference for Wind Power Drives (CWD) contains the collected contributions of the congress which took place on the 12th and 13th of March, 2019. The latest developments and innovations are presented in 37 articles covering the following topics: Gearbox - Torque Density, Gearbox - System Performance, Grid Conformity, Generator, Drive Train Concepts, Roller Bearings - Design and Testing, Roller Bearings - Loads, Wind 4.0 - Potential of Data Analytics, Wind 4.0 - Predictive Maintenance & Reliability, Plain Bearings and Condition Monitoring. The CWD has been held every two years since 2013 and acts as an interdisciplinary platform for knowledge and technology transfer between developers, researchers and operators. Furthermore, the conference promotes networking between industry and university in the field of wind turbine drive trains. The conference is supported by Mechanical Engineering Industry Association (VDMA) the Research Association for Drive Technology (FVA) and the IEEE Power Electronics Society.