Research On The Control Of Full Power Direct Drive Wind Power Converter

The development and utilization of wind energy can largely reduce the impact of energy and environment crisis on China’s development, China’s wind power technology in recent decades has been the rapid development, including direct-drive permanent magnet synchronous generating system has a very good development prospects and get a lot of attention, this paper combined with the actual needs of the wind power projects and project practical experience and aiming at researching and designing the control technology of 2MW full power converter in the direct-drive wind power system.This paper analyzes the four converter topologies used in direct-drive wind power system of present project. based on the difference between the wayside rectifier, rectifier can be divided into passive and active rectifier two kinds. According to the practical application, the active rectifier control mode is better and is used more in high-capacity converter. Based on this, this paper studies the back to back double PWM type full-power converter topologies. Through theoretical study, the machine side control strategy, network side control strategy, modules in parallel control technology and LVRT function technology in the full power converter are analyzed and summarized. According to the technical requirements of the project to design the full power converter control policy, machine-side part is zero d-axis current dual loop control strategy with speed of the outer ring and the inner ring current; for the network side need to control the DC side voltage stability and active and reactive power regulation functions, we propose a control strategy based on the current forecast; due to the single power module can’t meet the full power converter 2MW capacity currently, the paper chose four power modules a total of parallel bus topology, a zero vector control strategies was took to adjusted to suppress while there were circulation problems in parallel process; for the required low voltage traversal function, a hardware protection circuit and reactive power compensation control are combined to make it.Eventually, the paper takes the above control strategies to design the hardware and software systems based on DSP TMS320F2812 control and completes the product design, prototype testing by the type test was passed.Now the conventer has been put into operation in the wind farm, and the wind farm commissioning and actual operating results proved that the product was consistent with the design requirements with stable operation and good control effect.