Research on an Integrated Dual Mode DC Energy Metering Device and Metering Method

Abstract

In order to solve the problem of high precision and convenient measurement in DC distribution network, this paper has studied the integrated dual mode DC power metering device and its measurement method. The integrated dual-mode DC energy metering device mainly adopted the logical architecture of " MCU( Microcontroller Unit)+SOC( System-on -Chip)+ EM(Expansion Module)" to design, and adopted the mode of "mode setting + signal sampling + energy calculation" to realize DC energy metering. The electrical parameters were directly transmitted to the metering module of the device through the internally installed transformer to realize energy metering. Besides, the metering function module was independent from other modules, so that the software of the non-metering function module can be upgraded online without affecting the normal operation of the metering function. According to the actual business requirements, the integrated dual-mode DC energy metering device supported two modes that which could flexible switch between ±375V bipolar metering mode and ±375V symmetrical monopole metering mode, can avoid the occurrence of a pole line failure leading to the unable to normal measurement, so as to further ensure the stability, accuracy and convenience of DC measurement. The integrated dual-mode DC energy metering device and its metering method has been tested and verified. The test results showed that its metering accuracy and functional performance can meet the requirements of GB/T 33708-2017 Static meter for direct current energy, and which can be applied into the DC distribution network business scenarios.