Abstract
The electric energy is a guarantee to national economy and daily life in
modern society. With the fast development of the society, contradiction
between the demand and production of electrical energy occurs.
Time-scheduled tariff system, that changes user's behavior in energy
consuming and rationalizes the electrical energy utilization, is an effective and
valuable measure to solve this problem. For the energy measurement the
traditional mechanical electricity meter no longer can meet the requirements
of this new tariff system, and microcontroller-based digital E-meter becomes
the prerequisite and backbone of this tariff system.
This paper presents a AT89C51 power metering system as the core,
microcontroller through the AD7751 on the grid voltage and current sampling,
after internal processing after output in the form of frequency, given the
frequency measurement microcontroller to calculate the active power,
integration of time available after power, clock chip DS1302 provides the
current time information, the processor will power, electricity and time of
data sent to LCD display, separate keyboard, the user can work on the state of
the system operation, including setting time, time and power and the tariff, in
the past hour of electricity and electricity inquiries. The design of voltage and
current acquisition circuits with features and cost advantages; Design
methods that integrates the AT89C51s limited hardware and software
resources to implement real-time clock ,IC and serial communication
