Real time energy detection system of wireless sensor network node

Abstract

The invention relates to a real-time energy detecting system for a wireless sensor network node. The real-time energy detecting system provided by the invention consists of a stand alone type coulometer chip DS2786 which is based on open-circuit voltage (OCV) and belongs to Maxim company, a control core which is an ultra low power microcontroller C8051F920 belonging to Silicon Laboratories company, and peripheral circuits thereof. The invention provides a hardware solving proposal for energy management of a low power-consumption wireless sensor network node; the solving proposal includes: according to the OCV of the battery being unused for a period of time, available electric quantity of a chargeable lithium ion battery and a lithium ion polymer battery is estimated; relative electric quantity is estimated by a coulometer when discharging at high speed; compensation is carried out according to the detected temperature data to obtain more accurate dump energy value of the battery.

Description

【Technical field】: [0001] The invention relates to a real-time energy detection system of a wireless sensor network node, in particular to a low power consumption, high-precision lithium battery power detection method. 【Background technique】: [0002] The wireless sensor nodes are small in size and generally carry batteries with very limited energy. When the battery power is exhausted, the nodes will fail immediately. Therefore, the detection of node energy is of great significance for estimating node lifetime and communication capability. Node energy is also the first factor to be considered when performing cluster head rotation in a hierarchical network. The earliest applied method is to obtain the remaining capacity by monitoring the open circuit voltage of the battery. This is because there is a definite relationship between the battery terminal voltage and the remaining capacity, and the remaining capacity can be estimated by measuring the battery terminal voltage. Th...

AI Technical Summary

Problems solved by technology

The limitations of this method are: 1) For batteries produced by different manufacturers, the relationship between the open circuit voltage and capacity is different

2) Relatively accurate results can only be obtained by measuring the open circuit voltage of the battery at no load, but most applications need to know the remaining capacity of the battery during operation. At this time, the voltage drop generated by the load current on the internal resistance will affect the open circuit voltage. Voltage Measurement Accuracy

However, the dispersion of the internal resistance of the battery is very large, and this dispersion will become larger as the battery ages, so it will be very difficult to compensate for the error caused by the voltage drop

To sum up, the method of estimating the remaining capacity of the battery in real time through the open circuit voltage cannot achieve sufficient accuracy in practical applications, and can only provide a rough reference value

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