An Instantaneous Load-Sharing Parallel Control Method Using Improved PWM-Capture With DMA in a Power Conversion System

Abstract

As power demand from electric vehicles and digital loads increases, the use of direct current power supplies is increasing. As a result, the application of microgrid utilizing various distributed power systems is expanding. As demand power and load capacity increase, parallel operation of multiple power converters is required to increase the capacity of power converters used in distributed power systems. Among parallel control methods, load sharing through communication has a significant effect on control performance due to communication speed and reliability. This paper proposes an instantaneous load-sharing parallel control method using a high-speed communication method that can transmit data necessary for load-sharing every control cycle. The proposed communication method uses enhanced PWM and capture communication using a DMA module to compensate for the shortcomings of the existing method using PWM and capture functions. Whenever the master voltage controller is executed, the data required for parallel operation is updated, and by transmitting this data to the slave, instantaneous load sharing control with high speed response is possible. We explain the communication and system architecture of the proposed method and present the communication protocol specifications and design. The performance and validity of the proposed instantaneous load sharing parallel control method were verified through simulation and experiments.

Keywords

• Parallel control methods
• current distribution
• pulse width modulation (PWM)
• direct memory access (DMA)
• power conversion