APF Parallel Current Research And Application Of A Variety Of Communication Technologies

As an electronic devices to improve power quality,active power filter has becomea hot spot for distribution system harmonic suppression technology research in recentyears.This paper proposed using multiple ways to increase the compensation capacityof the device to compensate for the small size and single communicationproblem,focused on the expansion of the communication.This paper mainly studiedfrom the following aspects:This paper expounds the source of the subject, the development of the APF, theresearch status at home and abroad, and analyses the present problems of the APF, andincreases APF compensation capacity by parallel operation.Using USBcommunication and Ethernet communication to improve the diversity and flexibilityof active power filter device.This paper introduces the basic knowledge of communication technology.Theserial port communication is simple and convenient to realize serial communicationway, which most widely used communication industrial field.USB communicationmode’s communication rate is faster than a serial port communication, and can realizehot plugging of the equipment.The characteristics of the Ethernet communication isconvenient to connect with other equipment in industrial interconnection.The parallel operation of the APF structure and the use of parallel currentevenness technology for coordination control module are given, and the technique canbe convenient for many sets of APF module extension.Communication scheme ofsystem is given, and determine the traffic and formulated the communication protocolin detail through analyzing the function of the communication process.The APF module communication part,the hardware circuit and software programis presented.The outside of the hardware circuit mainly includes DSP extension circuit,I/O port extension circuit and communication circuit.USB and Ethernet functionanalysis were carried out for each circuit.For three kinds of communication mode,gives the key code and software program flow chart of software, the software programis referring to the APF control chip DSP program module.Function test of three kinds of communication mode can be used in APF systemflow.Simple serial communication and USB communication mode to a single APFcommunication test module, and Ethernet communication technology is flexible andeasy to many sets of APF module interconnection network interconnection, the APF system flow to the Ethernet communication has carried on the detailed test, verifiedthe validity of the scheme.For the development of APF, this paper puts forward many sets of APF operationflow structure through the expansion of the system for a variety of communicationmode, and gives the hardware circuit and software program structure.