RU113366U1 - ELECTRIC ENERGY METER - Google Patents

Abstract

An electric energy meter containing a current transformer, the primary winding of which is included in the section of the phase wire in series with the load, and both ends of the secondary winding are connected to the current circuit of the measuring and computing unit, the voltage circuit of which is connected to the phase and neutral wires, and the neutral wire is a common bus meter, which is connected to the second inputs, respectively, of the input circuit of the power supply, voltage stabilizer and power supply circuit of the measuring and computing unit, while the first input of the input circuit of the power supply is connected to the phase wire, and its second output is connected to the first input of the voltage stabilizer, the first output of which connected to the first input of the power supply circuit of the measuring and computing unit, characterized in that a rectifier, a key and a capacitor are introduced into it, and both inputs of the rectifier are connected in parallel with the secondary winding of the current transformer, its second output is connected to the common bus, and the first the output is connected to the input of the key, the output of which is connected to the first output of the capacitor and the first input of the voltage stabilizer, the second output of the capacitor is connected to the common bus, and the control input of the key is connected to the first output of the voltage stabilizer.

Description

The proposed utility model relates to electrical engineering and can be used to measure electrical energy (EE).

Known electric energy meter (S. Schaner, K. Venkat Implementing An Electronic Watt-Hour Meter With MSP430FE42x (A) / FE42x2 Application Report. SLAA203C-June, 2004 - Revised April 2009, Texas Instruments, Fig 1), containing in the current circuit a shunt included in the dissection of the phase wire in series with the load, and a power supply at the input connected to the zero and phase wires.

However, this counter, when disconnected from the neutral or phase wire, completely ceases to function.

In addition, an EE meter is known which is a prototype of this utility model (S. Schaner, K. Venkat Implementing An Electronic Watt-Hour Meter With MSP430FE42x (A) / FE42x2 Application Report. SLAA203C-June, 2004 - Revised April 2009, Texas Instruments, Fig 2), which contains a current transformer, the primary winding of which is included in the dissection of the phase wire in series with the load. Both ends of the secondary winding are connected to the current circuit of the measuring and computing unit, the voltage circuit of which is connected to the phase and neutral wires, and the neutral wire is a common counter bus. The common bus, in addition, is connected to the second inputs: the rectifier device of the power source, voltage stabilizer and power supply circuit of the measuring and computing unit. The first input of the input device of the power source is connected to the phase wire, and its second output is connected to the first input of the voltage regulator, the first output of which is connected to the first input of the power circuit of the measuring and computing unit.

However, this EE meter cannot account for the charge of the current flowing through the phase wire into the load when disconnecting the zero or phase wire from the meter.

The objective of the utility model is to measure the charge of the current flowing through the phase wire into the load when disconnecting the zero or phase wire from the meter.

This object is achieved by the fact that in the electric energy meter containing a current transformer, the primary winding of which is included in the phase wire cut in series with the load, and both ends of the secondary winding are connected to the current circuit of the measuring and computing unit, the voltage circuit of which is connected to the phase and neutral wires moreover, the neutral wire is the common bus of the counter, which is connected to the second inputs: the input circuit of the power source, voltage regulator and power supply circuit of the measuring and computing computer unit, while the first input of the input circuit of the power source is connected to the phase wire, and its second output is connected to the first input of the voltage regulator, the first output of which is connected to the first input of the power circuit of the measuring and computing unit, a rectifying device, a key, and a capacitor are introduced, than both inputs of the rectifier device are connected parallel to the secondary winding of the current transformer, its second output is connected to a common bus, and the first output is connected to the input of the key, the output of which is connected to the first output of the capacitor at the first input of the voltage regulator, the second output of the capacitor is connected to a common bus, and the control input of the key is connected to the first output of the voltage regulator.

In FIG. The functional diagram of the EE meter is shown. The counter contains:

- Current transformer (TT) 1;

- Measuring and computing unit (IVB) 2;

- The rectifying device (VU) 3;

- Key (K) 4;

- Capacitor 5

- The input circuit of the power source (VTsIP) 6;

- Voltage stabilizer (CH) 7.

Phase and neutral wires are connected to the first and second inputs of VTsIP 6 and voltage circuit IVB 2, respectively, with the neutral wire connected to a common bus (ground) of the meter. In addition, the second outputs of the VTsIP 6, VU 3, CH 7, the second output of the capacitor 5, as well as the second input of the CH 7 and the second input of the power supply circuit of the IVB 2 are connected to the common bus. The first output of the VU 3 is connected to the input of the key 4, the output of which is connected with the first output of the capacitor 5, the first input of the SP 7 and the first output of the VTsIP 6. The first output of the SP 7 is connected to the first input of the power supply cable IVB 2, as well as to the control input of the key 4. The primary winding of the CT 1 is included in the cut-out of the phase wire, and the outputs are secondary windings are connected to inputs of VU 3 and current circuit IVB 2.

Current transformer 1 can be made on a metal core with primary and secondary windings wound, VU 3 rectifying device assembled on BAV70 diodes connected by a bridge circuit, key 4 is made on IRLML2803 transistor, capacitor 5 is of type RO-10, VTsIP 6 is made by circuit of a capacitive voltage divider, half-wave rectifier and parametric stabilizer and is assembled on a SM2000 diode, IRFR1N60A transistor, two Zener diodes BZV55C10 and SMBJ300A, resistors and capacitors, voltage regulator 7 - type TP562051, measuring and calculating Call duration unit 2 - type ADE5569.

The proposed counter works as follows. In the initial state, when there is no disturbance in the connection between the VTsIP 6 inputs and the neutral or phase wire, there is a supply voltage at the output of SP 7, for example, 3 V, which supplies the IVB 2 and breaks the key 4 through the control circuit. The counter operates in normal mode. When the open switch 4 is closed, the rectifier device is closed and does not load the CT 1. In case of a breakdown of the VTsIP 6 and a zero or phase wire at the output of the VTsIP 6, the voltage decreases below a certain level, for example 4 V. The output voltage of CH 7 then becomes zero. This leads to the cessation of the operation of the IVB 2 (except for the clock, which in all modern electronic meters is powered by a lithium cell) and the opening of the key 4. The current of the secondary winding of the TT 1 through the rectifier 3 and the public key 4 charges the capacitor 5 to a predetermined voltage level, for example, 8 V. This causes the CH 7 to turn on and a power voltage appears on its output, which turns on the IVB 2 and breaks the key 4. The secondary winding current enters the input of the IVB 2 current circuit, where it is integrated modulo. This continues until the capacitor 5 is discharged to a certain level, for example, 4 B. After that, the CH 7 turns off and then the counter goes into the charge mode of the capacitor 5, as described above. In the future, this mode of operation of the counter (charge-discharge of the capacitor 5) is maintained until the connection between the zero or phase wire and the inputs of the VTsIP 6 is restored. In this mode, the meter measures the charge of the load current over time while the CH 7 is working. Since Since the meter’s clock works regardless of the supply voltage at the output of CH 7, the information on the charge and discharge time of the capacitor 5 is determined in IVB 2 and then the total charge flowing through the phase wire to the load is calculated by the rectangular approximation method.

The introduction of a rectifying device 3, a key 4, and a capacitor 5 with corresponding connections into the meter allows the meter to measure the charge flowing through the phase wire into the load. This makes it possible to estimate the consumed electricity by the consumer in case of a communication failure (possibly intentional) between the zero or phase wire and the meter. Estimation of the consumed EE can be done on the basis that the voltage value in the network varies in a narrow range (GOST 13109-97) of the order of + -10% of the nominal value. In the same error range, the consumed electricity can be estimated by multiplying the measured charge of the load current by the rated voltage, for example, 220 V.

Claims (1)

An electric energy meter comprising a current transformer, the primary winding of which is connected in series with the phase conductor in series with the load, and both ends of the secondary winding are connected to the current circuit of the measuring and computing unit, the voltage circuit of which is connected to the phase and neutral wires, and the neutral wire is a common bus counter, which is connected to the second inputs, respectively, of the input circuit of the power source, voltage stabilizer and power circuit of the measuring and computing unit, while the first the input circuit of the power source is connected to a phase wire, and its second output is connected to the first input of the voltage regulator, the first output of which is connected to the first input of the power circuit of the measuring and computing unit, characterized in that a rectifying device, a key and a capacitor are introduced into it, both inputs of the rectifying device are connected parallel to the secondary winding of the current transformer, its second output is connected to a common bus, and the first output is connected to the input of the key, the output of which is connected to the first output of the conden sator and the first input of the voltage regulator, the second output of the capacitor is connected to a common bus, and the control input of the key is connected to the first output of the voltage regulator.