Control of grid-connected PMSG-based wind turbine system with back-to-back converters topology using a new PIL integration method

Abstract

This paper shows a new manner to exploit the STM32F407 board in order to perform the processor in the loop (PIL) testing by reducing significantly the co-simulation time. This method requires an FT232RL USB-UART converter board as an external serial communication interface. The main advantage of this external device lies in the setting of its baud-rate using the aliasing technique. This technique provides an efficient solution to transfer data between embedded board and computer at high baud-rate. It allows speeding up the PIL testing and, therefore, makes it more flexible. The studied grid connected wind-turbine system is based on permanent magnetic synchronous generator (PMSG) followed by back-to-back bidirectional converters. The grid side converter (GSC) ensures the DC bus voltage control as well as the unity power factor, while the machine side converter (MSC) ensures the PMSG speed control. The method of the decoupled current control is presented for the GSC. The optimum tip speed ratio (OTSR) algorithm–based maximum power point tracking (MPPT) technique is developed for MSC. Both power and control parts are initially designed and simulated in the same MATLAB/Simulink environment. Once the Simulink model behaves properly and meets the desired requirements, the proposed PIL test is then carried out. The C code is automatically generated from controllers and implemented on the STM32F407 board that acts as an external controller, meanwhile power part still works on the host computer. The PIL test results show the efficiency of the chosen control algorithms and dynamic behavior of the full wind-turbine system. They also show that the controllers simulated under MATLAB/Simulink behave in the same way once executed on the embedded board.