Object-Oriented Research And Development For DC Filters Design

With the rapid expansion of China’s electric power system scale and the rapid development of HVDC technology, DC filter design work in HVDC system has become more and more. DC filter design needs to consider performance indicators and technical economic factors. It usually requires repeated adjustments of design parameters and makes the process complex and inefficient, which claims high professional quality of designers. Extensive applications of computer technology in the power system have provided new ideas and methods for DC filter design. It has very practical value to apply the computer technique in the DC filters design.Firstly, the current development of HVDC technology was briefly summarized, the key technology and common algorithms of DC side harmonics calculation were introduced, the characteristics of the algorithms were compared, and the basic concept and main knowledge of object-oriented technology were presented. Secondly, the types of passive DC filter and equivalence algorithm of filter parameters were described, the functional requirements of filter design software was analyzed with object-oriented method, the overall design ideas, flow chart of calculation and software architecture were provided. Thirdly, on the basis of inheritance, encapsulation and polymorphism properties of class, the component class, frame class, parameter class and calculation class were designed, and the memory management and system optimization methods were given. Then, the system database was designed based on relational database, the user interface was designed based on windows forms, and the forms and software components were designed based on dynamic link techniques. In the last, the function introduction and instructions for use of the filter design software were given, and the software usability was tested via practical engineering application.