Electric energy meter with built-in virtual load

Abstract

The invention discloses an electric energy meter with a built-in virtual load. The electric energy meter comprises an electric energy meter shell, a virtual load circuit, a measuring circuit and a control unit. The electric energy meter shell is provided with a fire wire inlet port, a fire wire outlet port, a zero wire inlet port, a zero wire outlet port and a display screen. The virtual load circuit, the measuring circuit and the control unit are installed in the electric energy meter shell. The control unit is connected with the display screen arranged on the electric energy meter shell through control. The fire wire inlet port, the fire wire outlet port, the zero wire inlet port and the zero wire outlet port are connected with the signal input end of the measuring circuit through leads. The signal output end of the measuring circuit is connected with the control unit. The virtual load circuit comprises a current transformer, a resistor and a control switch. The virtual load circuit is directly arranged in the electric energy meter, and the control switch is pressed according to the requirements in testing so that operation is easy, safe and convenient, and normal and accurate testing can be performed under the condition of low user electricity utilization and even no electricity utilization.

Description

【Technical field】 [0001] The invention relates to the technical field of electric energy meters, in particular to an electric energy meter with a built-in virtual load. 【Background technique】 [0002] An electric energy meter is an instrument used to measure electric energy. When the watt-hour meter is connected to the circuit under test, alternating current flows through the current coil and the voltage coil, and these two alternating currents generate alternating magnetic flux in their iron cores respectively; the alternating magnetic flux wears Passing through the aluminum disc, an eddy current is induced in the aluminum disc; the eddy current is subjected to force in the magnetic field, so that the aluminum disc obtains active torque and rotates. The greater the power consumed by the load, the greater the current passing through the current coil, the greater the eddy current induced in the aluminum disc, and the greater the torque that makes the aluminum disc rotate. T...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and provide an electric energy meter with a built-in virtual load, which aims to solve the problem that the accuracy of the field test of the electric energy meter is easily reduced in the prior art due to the small power consumption of the user. On-site testing cannot be carried out without electricity, and it is troublesome to connect virtual loads to the site, which reduces work efficiency.

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