CN207601164U - Electric safety system residual current monitoring module - Google Patents

Abstract

The utility model discloses a residual current monitoring module of an electrical safety system, which comprises an MCU control circuit, a voltage measurement circuit, a storage circuit, a residual current measurement circuit, a switching value input and output circuit and an RS485 communication circuit, the MCU control circuit and the voltage measurement circuit, The storage circuit, the residual current measurement circuit, the switching value input and output circuit are connected with the RS485 communication circuit; the residual current measurement circuit is composed of a board-level coupling circuit for A/B/C/N four-wire current signals, a current signal conditioning circuit, and a filter circuit and a differential input circuit, the voltage measurement circuit is composed of a voltage transformer isolation circuit, a current-voltage conversion circuit and a filter input circuit, and the switch input and output circuit is composed of a control signal acquisition terminal, an optocoupler isolation circuit and an input and output circuit . The utility model can directly measure parameters such as three-phase current value, residual current value and voltage, without externally connecting a secondary transformer, so that it can be installed during continuous power-on, and is convenient to use.

Description

Electrical safety system residual current monitoring module

technical field

The utility model relates to a power collection device, in particular to a residual current monitoring module of an electric safety system.

Background technique

With the development of society and the improvement of people's living standards, various electrical devices and electricity consumption have gradually increased, causing more and more electrical fires, and the proportion of accidents caused by aging devices and wire insulation layers Also getting bigger and bigger. By detecting the current vector and residual current of each phase (including zero phase) of the distribution line in the distribution cabinet, the grounding condition of the distribution line can be judged, thereby reducing personal electric shock accidents, electrical fires and electrical device damage accidents.

The existing residual current measurement modules all need to pass the three-phase and neutral wires through the zero-sequence transformer, and then calculate the residual current. It needs to be continuously powered on, so that the power-off installation cannot be completed, and eventually the residual current cannot be collected.

Contents of the invention

Aiming at the problems existing in the above-mentioned prior art, the utility model provides a residual current monitoring module of an electrical safety system, in which a signal is connected to the module through a primary current transformer in a power distribution line, and the three-phase current value and residual current can be directly measured value, and can measure parameters such as voltage, power and harmonics, without the need for external secondary transformers, so it can be installed during continuous power-on, which is convenient to use.

In order to achieve the above purpose, the technical solution adopted by the utility model is: the residual current monitoring module of this electrical safety system includes an MCU control circuit, a voltage measurement circuit, a storage circuit, a residual current measurement circuit, a switch input and output circuit and an RS485 communication circuit , MCU control circuit is connected with voltage measurement circuit, storage circuit, residual current measurement circuit, switching value input and output circuit and RS485 communication circuit;

The residual current measurement circuit is composed of a board-level coupling circuit for A/B/C/N four-wire current signals, a current signal conditioning circuit, a filter circuit and a differential input circuit, and the board for A/B/C/N four-wire current signals The stage coupling circuit is connected with the current signal conditioning circuit, the current signal conditioning circuit is connected with the filter circuit, and the filter circuit is connected with the differential input circuit;

The voltage measurement circuit is composed of a voltage transformer isolation circuit, a current-voltage conversion circuit and a filter input circuit, the voltage transformer isolation circuit is connected to the current-voltage conversion circuit, and the current-voltage conversion circuit is connected to the filter input circuit;

The switching value input and output circuit is composed of a control signal acquisition terminal, an optocoupler isolation circuit and an input and output circuit. The control signal acquisition terminal is connected to the optocoupler isolation circuit, and the optocoupler isolation circuit is connected to the input and output circuit.

Further, the board-level coupling circuit for the A/B/C/N four-wire current signal is provided with a 5A/5mA current transformer.

Further, the control chip adopted by the MCU control circuit is an STM32F407 processing chip.

Compared with the prior art, the utility model adopts the combination of MCU control circuit, voltage measurement circuit, storage circuit, residual current measurement circuit, switching value input and output circuit and RS485 communication circuit, wherein the residual current measurement circuit is set at 5A/ The 5mA current transformer can replace the existing residual power collection device. After connecting the primary transformer of the power distribution line, the secondary transformer needs to be connected. The utility model only needs the primary transformer in the power distribution line, and can directly Collect the instantaneous values of the three-phase voltage, current and residual current of the distribution line in real time, and then obtain the power parameters such as active/reactive power, electric energy, power factor and harmonic current through the MCU control circuit; and store them in real time through the storage circuit The waveform data of the three-phase voltage and current collected is for viewing and analyzing the data after a fault occurs; then the RS485 communication circuit can be connected to the touch screen for viewing, or the data can be uploaded to the platform after connecting to the management machine, so that the monitoring center can obtain real-time and accurate information Grid operation data and grid operation status, and corresponding control operations. Since the utility model does not need to pass through the zero-sequence transformer, it solves the problems that the zero-sequence transformer cannot be installed at a long distance from the phase line and the zero line, and the current transformer cannot be installed in a power failure, so that it can be installed during continuous power-on, which is convenient for all place of use.

Description of drawings

Fig. 1 is the electric principle block diagram of the present utility model;

Fig. 2 is the circuit schematic diagram of the voltage measuring circuit in the utility model;

Fig. 3 is the electrical principle block diagram of residual current measuring circuit in the utility model;

Fig. 4 is a circuit schematic diagram of the residual current measuring circuit in the utility model.

Detailed ways

The utility model will be further described below.

As shown in Figures 1 to 4, the utility model includes an MCU control circuit, a voltage measurement circuit, a storage circuit, a residual current measurement circuit, a switch input and output circuit and an RS485 communication circuit, an MCU control circuit, a voltage measurement circuit, a storage circuit, The residual current measurement circuit, the switch value input and output circuit and the RS485 communication circuit are connected;

The residual current measurement circuit is composed of a board-level coupling circuit for A/B/C/N four-wire current signals, a current signal conditioning circuit, a filter circuit and a differential input circuit, and the board for A/B/C/N four-wire current signals The stage coupling circuit is connected with the current signal conditioning circuit, the current signal conditioning circuit is connected with the filter circuit, and the filter circuit is connected with the differential input circuit;

The voltage measurement circuit is composed of a voltage transformer isolation circuit, a current-voltage conversion circuit and a filter input circuit, the voltage transformer isolation circuit is connected to the current-voltage conversion circuit, and the current-voltage conversion circuit is connected to the filter input circuit;

The switching value input and output circuit is composed of a control signal acquisition terminal, an optocoupler isolation circuit and an input and output circuit. The control signal acquisition terminal is connected to the optocoupler isolation circuit, and the optocoupler isolation circuit is connected to the input and output circuit.

Further, the board-level coupling circuit for the A/B/C/N four-wire current signals is provided with a 5A/5mA current transformer.

Further, the control chip adopted by the MCU control circuit is an STM32F407 processing chip.

The above-mentioned parts of the circuits that make up the utility model are all well-known circuits in the art, and individual circuits can be directly obtained from the market as packaged finished products.

Connect the utility model to the primary transformer of the power distribution equipment, and measure the residual current: the residual current signal is coupled through the board-level coupling circuit of the A/B/C/N four-wire current signal, and then through its After the 5A/5mA current transformer performs mutual inductance, it is passed to the MCU control circuit after the corresponding functions of the current signal conditioning circuit, filter circuit and differential input circuit; voltage measurement: the high-voltage AC signal is connected to the precision circuit through the terminal and the current limiting resistor. The current-type voltage transformer, after isolation, is sent to the MCU circuit through the voltage conversion matching circuit and the filter input circuit, and finally the MCU control circuit obtains power parameters such as active/reactive power, electric energy, power factor, voltage, and harmonic current; and The collected three-phase voltage and current waveform data can be stored in real time through the storage circuit, so that the data can be viewed and analyzed after a fault occurs; then the RS485 communication circuit can be connected to the touch screen for viewing, or connected to the management machine to upload the data to the platform.

Claims (3)

1. An electrical safety system residual current monitoring module is characterized in that it comprises an MCU control circuit, a voltage measurement circuit, a storage circuit, a residual current measurement circuit, a switching value input and output circuit and an RS485 communication circuit, an MCU control circuit and a voltage measurement circuit , storage circuit, residual current measurement circuit, switching value input and output circuit and RS485 communication circuit connection; The residual current measurement circuit is composed of a board-level coupling circuit for A/B/C/N four-wire current signals, a current signal conditioning circuit, a filter circuit and a differential input circuit, and the board for A/B/C/N four-wire current signals The stage coupling circuit is connected with the current signal conditioning circuit, the current signal conditioning circuit is connected with the filter circuit, and the filter circuit is connected with the differential input circuit; The voltage measurement circuit is composed of a voltage transformer isolation circuit, a current-voltage conversion circuit and a filter input circuit, the voltage transformer isolation circuit is connected to the current-voltage conversion circuit, and the current-voltage conversion circuit is connected to the filter input circuit; The switching value input and output circuit is composed of a control signal acquisition terminal, an optocoupler isolation circuit and an input and output circuit. The control signal acquisition terminal is connected to the optocoupler isolation circuit, and the optocoupler isolation circuit is connected to the input and output circuit. 2. A residual current monitoring module of an electrical safety system according to claim 1, wherein a 5A/5mA current transformer is provided in the board-level coupling circuit of the A/B/C/N four-wire current signal . 3. A residual current monitoring module for an electrical safety system according to claim 1, wherein the control chip used in the MCU control circuit is an STM32F407 processing chip.