Research On Digital Control Platform For Power Electronics Integrations

Power Electronic Systems Integration (PESI), a key research area in modern power electronics, pushes the power electronic techniques towards integration, standardization and modularization. It was under the background of systems integration that the research on Digital Control Platform (DCP) for power electronics was carried out, whose objectives are to change the design methods of digital control systems for power electronics, to shorten the system development cycle, and to meet the requirements of PESI development. The research will enrich PESI. At present, the research mainly focuses on the digital control platform for medium- or high-power system or complex power electronics equipment, such as high-power active power filter, motion control and renewable energy generation system. According to these objectives and its applications, the dissertation conducts the theoretical and experimental studies on some key problems of DCP, covering the general design rules for the platform, analysis of extendibility of the platform, integrations of hardware and software resources for the platform, and its applications.How to design hardware platform from the angle of integration is a key problem, which should be solved first in DPC research. Based on the detailed analysis of requirements of computation resources, communication capabilities and precision and speed of peripherals, the dissertation proposes general design rules for digital control platform, including selection criteria of the core processor, communication types, AD/DA converters and digital PWM, and interface devices. It also puts forward a design scheme of programmable and configurable extension interfaces using programmable logic devices.The versatility and extendibility are the prerequisites of DCP. Under the guidance of the general design rules for digital control platform, the dissertation fulfills the hardware design of the platform. On the basis of the hardware platform, the dissertation conducts the experimental researches on the versatility and extendibility of the digital control platform from different levels. On platform system level, the dissertation puts forward several schemes for configuring the multi-platform structure from different angles and different realization methods. On hardware extension level, the dissertation makes use of PWM IP(Intellectual Property) core to extend PWM channels. On computation resource level, the dissertation adopts the FPGA to configure the floating-point units to enhance the computation capacity of the platform, compensating the deficiency of the fixed-point processor on the platform.The core of the DCP is the integration of software resources. Centering the core, the dissertation carries out the researches in following two aspects: reusable software modules and IP soft cores for power electronics. In the aspect of reusable software modules, the dissertation puts forward three basic principles for reusable software module design in power electronics :â‘ classification;â‘¡function independency;â‘¢interface-oriented design methods. Under the guidance of these principles, the dissertation demonstrates how to design the reusable software module in details. Due to the problem caused by the interface design method using fixed-scaling mode in fixed-point software modules, the dissertation proposes a design scheme for the interface of reusable software modules using dynamic-scaling mode. In the aspect of IP soft core, by systematically discussing research status, meanings of IP cores and basic methodology of IP core classification and design, the dissertation outlines the preliminary methodology of IP core research and design. Using three-level space vector modulation IP core as a design case, the dissertation emphasizes the general design rules for IP cores, including simplified algorithms, design flow, implementation and verifications.In the end, the integrated digital platform is applied in three typical applications from different fields: three-phase inverter source with output isolation using line frequency transformers, integrated elevator controller and photovoltaic generation system. These applications demonstrate the validality and practicability of design rules and integration methodologies of hardware and software resouces for digital control platform.