The control of a three-phase PWM regenerative rectifier

Abstract

The use of renewable generators has increased intensively as a response to global warming. The target is to develop these technologies to diminish the environmental impacts and ensure reliable and cost-effective energy. Wind power is one of the fastest- growing clean energy technologies to replace fossil fuel-based power generation units and support energy security. When using these types of generators, the major challenge is their dependency on weather conditions, causing their power output to be unreliable. In such a case, power electronics converters are used as interfaces between the wind generators and the loads. Depending on the type of loads, power electronics for wind power applications can be either AC to DC (rectifiers) or DC to AC converters (inverters) or a combination of both types (back to back converters). However, this research focuses on AC to DC converters. Two main topologies of AC to DC converters can be found; the line commutated rectifiers and power factor correction rectifiers. The power factor correction rectifiers consist of PWM regenerative and PWM non-regenerative rectifiers. In PWM regenerative rectifiers, a proper control scheme must operate the rectifier efficiently and maintain the output voltage to a stable value. This study aims to develop a control scheme for a three-phase PWM regenerative rectifier receiving AC power from a 1.53 MW permanent magnet synchronous wind generator at a line voltage of 953 V. The rectifier delivers 1.26 MW at a DC voltage of 1150 V to a DC load connected to its output terminals. The control system scheme adopted in this study is based on a voltage-oriented control strategy. The modelling and simulation are performed using the Matlab/Simulink environment. Three types of loads, namely R, RL, and RC loads, are considered to evaluate the designed controller's performance. The results show a good performance of the designed controller as the output voltage could be maintained close to the set reference value. At the same time, the rectifier delivered 1.26 MW to the load.