Design Of The Vehicle DC Smart Watt-hour Meter

With the development of the electric car industry, car battery charging and changing industries and other supporting industries are studying and applying in pilots. Battery for electric mode is one of the ways to add electric vehicle energy, so it can meet the current characteristics of quick and efficient operation. Therefore, designing vehicle direct-current smart meters which can measure accuracy and have high reliability to adapt to the application environment of complex vehicle circuit, will become the focus in the study of various instruments manufacturers.Firstly, the paper introduces the development background of electric cars’ vehicle measurement, reviews several kinds of charging and changing modes of electric cars, discusses the development status of vehicle DC meters and application prospect in the electric current mode change. In the current domestic electric vehicle charging and changing mode, electric bus with specific needs on the basis of the electrical measurement, the paper introduces the main performance and function of vehicle DC meters. Taking the single-chip microcomputer as the core, applying the modular design technology, so the vehicle DC intelligent electric energy meter is designed. The whole hardware system comprises power management module, infrared communication module, RS485 communication module, clock and storage module, display module and measurement module, etc. The reliability of the design of each module is the research focus, and the each circuit module of principle analysis and theoretical calculation is based on, therefore the hardware circuit of each module is designed. According to the design idea of software platform, the DC meter software is divided into several functional independent modules, which of the main process design and metering unit module and communication module are being mainly researched, the corresponding software program is designed. The software part of each module is independent developed, with a unified format and specifications. It uses the interface between modules, so it is convenient to access and call,and the function of each module can be configured according to specific needs, which makes the whole software design easy to develop and maintain.Practical application test and operation show that the vehicle DC smart meters have the advantages of stable work, reliable performance, accurate measurement, etc. which meet the established design requirements, completely satisfy the domestic market demand for the vehicle DC meters and have broad application prospects.