CN106324421A - Electric leakage fault monitoring device for power grid transformer - Google Patents

Abstract

The invention discloses a power grid transformer leakage fault monitoring device. The output terminal of the voltage transformer is connected to the signal conditioning circuit, and the signal conditioning circuit, alarm circuit, and wireless communication module are respectively connected to the main processor; the bus self-feeding power circuit is connected to the power module, and the power module supplies power to the device. The invention promptly reminds the operation and maintenance personnel to make a treatment, which is convenient for the operation and maintenance personnel to quickly find the fault point, shortens the maintenance time, and reduces economic losses.

Description

A power grid transformer leakage fault monitoring device

technical field

The invention relates to a power grid transformer monitoring device, in particular to a power grid transformer leakage fault monitoring device capable of monitoring transformer leakage faults.

Background technique

When the power grid transformer trips due to leakage faults such as short circuit or grounding, if there is no user report for repairing the fault, the management personnel of the station area cannot grasp the operation status of the power distribution in the station area in real time. After the power distribution outage in the station area, the user's collection terminals and meters were powered off. If the power is not restored in time, the collection terminals cannot upload the frozen data of the meters, resulting in a large amount of abnormal data.

Contents of the invention

In order to solve the above problems, the present invention provides a power grid transformer leakage fault monitoring device that can monitor leakage faults in real time and remind management personnel in time.

The technical solution of the present invention is: a power grid transformer leakage fault monitoring device, including: a main processor, a voltage transformer, a signal conditioning circuit, an alarm circuit, a bus self-fetching power circuit, a wireless communication module, and a power module;

The input end of the voltage transformer is connected to the load side of the transformer, the output end of the voltage transformer is connected to the signal conditioning circuit, and the signal conditioning circuit, the alarm circuit, and the wireless communication module are respectively connected to the main processor; Take the power circuit and connect it with the power module, and the power module supplies power to the device;

The bus self-fetching power supply circuit includes a rectangular power-taking iron core and a voltage conditioning circuit; the input end of the rectangular power-taking iron core is wound around the bus bar, and the output end of the rectangular power-taking iron core is wound with a secondary coil, and the secondary coil is connected to the Voltage conditioning circuit connection;

The voltage conditioning circuit includes an input voltage dividing resistor, a voltage comparator, a positive half cycle amplitude setting unit, a negative half cycle amplitude setting unit, a photoelectric coupling output unit, a thyristor electronic switch and a release resistor; the input voltage dividing resistor, the voltage comparator , the photoelectric coupling output unit, the thyristor electronic switch and the release resistor are sequentially connected in series to the power module, the voltage comparator is respectively connected to the positive half cycle amplitude setting unit and the negative half cycle amplitude setting unit 25, and the thyristor electronic switch is grounded.

Further, it also includes an instantaneous high voltage protection circuit, the instantaneous high voltage protection circuit includes a shrapnel T, a varistor R2, a resistor R3, a resistor R4, a rectifier bridge U1, a filter capacitor C1, an optocoupler U2 and an indicator light L2, the shrapnel T. The varistor R2 is connected in series with the power supply, the resistor R3 is connected in series with the rectifier bridge U1 and connected in parallel with the varistor R2, the filter capacitor C1 is connected in series with the rectifier bridge U1, the resistor R4, the indicator light L2 and optocoupler U2 are connected in parallel with the filter capacitor C1.

Further, the alarm circuit resistor R1, transistor Q1, relay K1, indicator light L1, buzzer Y; one end of the resistor R1 is connected to the output end of the main processor, the other end of the resistor R1 is connected to the base of the transistor Q1, and the transistor Q1 The emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the voltage source through the coil of the relay K1, and the contact of the relay K1 is connected to the serially connected indicator light L1 and buzzer Y.

Further, the wireless communication module is a GPRS module.

Further, the GPRS module is connected with a SIM card interface module.

Further, the main processor is an STM32F103RET6 processor based on a Cortex-M3 core.

Further, a storage module is also included, and the storage module is connected with the main processor.

Further, a USB interface module is also included, and the USB interface module is connected with the main processor.

The power grid transformer leakage fault monitoring device provided by the present invention uses a voltage transformer to collect the voltage on the load side of the transformer and transmits it to the main processor in real time. If the side loses pressure, the main processor transmits the alarm signal to the remote control terminal through the wireless communication module or sends it to the operation and maintenance personnel in the form of a short message, so as to remind the operation and maintenance personnel to deal with it in time, so that the operation and maintenance personnel can quickly find the fault point and shorten the time. Maintenance time, reduce economic losses, etc. The power supply of the device is taken from the bus bar, which is convenient for power supply, and is equipped with a voltage conditioning circuit to stabilize the output voltage.

Description of drawings

Fig. 1 is a schematic diagram of the principle of a specific embodiment of the present invention.

Fig. 2 is a schematic circuit diagram of a bus self-acquiring power supply circuit.

FIG. 3 is a schematic circuit diagram of a voltage conditioning circuit.

Figure 4 is a schematic circuit diagram of the alarm circuit.

Fig. 5 is a schematic circuit diagram of an instantaneous high voltage protection circuit.

In the figure, 1 voltage transformer, 2 signal conditioning circuit, 3 self-feeding power supply circuit of busbar, 4 power supply module, 5 instantaneous high voltage protection circuit, 6 main processor, 7 alarm circuit, 8 wireless communication module, 9 storage module, 10USB interface Module, 11 bus bar, 12 rectangular electric iron core, 13 secondary side coil, 14 voltage conditioning circuit, 15 input voltage dividing resistor, 16 voltage comparator, 17 positive half cycle amplitude setting unit, 18 negative half cycle amplitude setting unit , 19 photoelectric coupling output unit, 20 thyristor electronic switch, 21 release resistor, R1, R3, R4 resistor, R2 varistor, L1, L2 indicator light, Y buzzer, C1 filter capacitor, U1 rectifier bridge, U2 optocoupler , T shrapnel.

detailed description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

As shown in Figure 1, the power grid transformer leakage fault monitoring device provided by the present invention includes a main processor 6, a voltage transformer 1, a signal conditioning circuit 2, an alarm circuit 7, a bus self-fetching power supply circuit 3, a wireless communication module 8, a power supply Module 4.

The input end of the voltage transformer 1 is connected to the load side of the transformer, the output end of the voltage transformer 1 is connected to the signal conditioning circuit 2, and the signal conditioning circuit 2, the alarm circuit 7, and the wireless communication module 8 are respectively connected to the main processor 6. The bus self-feeding power circuit 3 is connected to the power module 4, and the power module 4 supplies power to the device. In this embodiment, the main processor 6 can adopt the STM32F103RET6 processor based on the Cortex-M3 core, with fast processing speed and timely alarm. Wireless communication module 8 can adopt GPRS module, and GPRS module is connected with SIM card interface module, to realize SMS alarm, convenient and timely. The device is also provided with a storage module 9 and a USB interface module 10, and the storage module 9 and the USB interface module 10 are respectively connected to the main processor 6. The storage module 9 is used to store fault information, and the USB interface module 10 is connected to the USB to export the fault information for subsequent statistical analysis.

As shown in Figure 2, the busbar self-fetching power supply circuit 3 includes a rectangular electric iron core 12 and a voltage conditioning circuit 14; the input end of the rectangular electric iron core 12 is wound around the bus bar 11, and the output end of the rectangular electric iron core 12 is wound around the secondary side The coil 13 and the secondary coil 13 are connected to a voltage conditioning circuit 14 .

As shown in Figure 3, the voltage conditioning circuit 14 includes an input voltage dividing resistor 15, a voltage comparator 16, a positive half cycle amplitude setting unit 17, a negative half cycle amplitude setting unit 18, a photoelectric coupling output unit 19, and a thyristor electronic switch 20 and release resistor 21; wherein the input voltage dividing resistor 15, voltage comparator 16, photoelectric coupling output unit 19, thyristor electronic switch 20 and release resistor 21 are connected in series to the power supply module 4 in sequence, and the voltage comparator 16 is respectively connected to the positive half cycle amplitude The setting unit 17 is connected to the negative half cycle amplitude setting unit 18, and the thyristor electronic switch 20 is grounded.

The voltage conditioning circuit 14 uses a voltage comparator 16 to detect the amplitudes of the three-phase AC voltage in both positive and negative directions, and compares the detected amplitude with the preset voltage value. Once the amplitude of any signal exceeds the preset setting value, the thyristor gate is opened to discharge the energy of the overvoltage amplitude, and once the overvoltage amplitude returns to below the set value, the thyristor gate is closed, and the measured signal Normally enter the meter for metering. The voltage conditioning circuit 14 can conveniently set any overvoltage amplitude of the voltage of the bus bar 11 .

As shown in Figure 4, the alarm circuit 7 has a resistor R1, a transistor Q1, a relay K1, an indicator lamp L1, and a buzzer Y; one end of the resistor R1 is connected to the output terminal of the main processor 6, and the other end of the resistor R1 is connected to the base of the transistor Q1 , the emitter of the triode Q1 is grounded, the collector of the triode Q1 is connected to the voltage source through the coil of the relay K1, and the contact of the relay K1 is connected to the indicator lamp L1 and the buzzer Y connected in series.

As shown in Figure 5, the device is also provided with an instantaneous high voltage protection circuit 5, which includes a shrapnel T, a varistor R2, a resistor R3, a resistor R4, a rectifier bridge U1, a filter capacitor C1, an optocoupler U2 and an indication Lamp L2; shrapnel T, varistor R2 are connected in series with the power supply, resistor R3 is connected in series with the rectifier bridge U1, and connected in parallel with the varistor R2, filter capacitor C2 is connected in series with the rectifier bridge U1, resistor R4, indicator light L2 and optocoupler U2 are connected with the filter Capacitor C1 is connected in parallel.

When the instantaneous high voltage such as lightning invades from the power cable, the varistor R2 and the shrapnel T will first be activated, and the varistor R2 will produce a voltage limiting effect, which will limit the rise of lightning impulse voltage and protect the subsequent equipment; when the varistor R2 suffers from excessive When it is damaged by lightning and heats up, the low-temperature welding structure of the shrapnel T can quickly separate from the circuit to ensure that the instantaneous high-voltage protection circuit 5 does not overheat; while the rear stage of the circuit is stepped down by resistor R3, rectified by rectifier bridge U1 and filtered by filter capacitor C1. The alarm is displayed through the indicator light L2, and the normal signal output of the optocoupler U2 is connected at the same time; when the action of the shrapnel T is disconnected, the indicator light L2 goes out, and the output of the optocoupler U2 is turned off, so as to indicate the working state of the instantaneous high voltage protection circuit 5; the shrapnel T is separated from the circuit The reliability is high and will not cause safety accidents.

The above disclosure is only a preferred embodiment of the present invention, but the present invention is not limited thereto, any non-creative changes that those skilled in the art can think of, and some improvements and modifications made without departing from the principle of the present invention , should fall within the protection scope of the present invention.

Claims (8)

1. A power grid transformer leakage fault monitoring device is characterized in that, comprising: a main processor, a voltage transformer, a signal conditioning circuit, an alarm circuit, a bus-bar self-fetching power supply circuit, a wireless communication module, and a power supply module; The input end of the voltage transformer is connected to the load side of the transformer, the output end of the voltage transformer is connected to the signal conditioning circuit, and the signal conditioning circuit, the alarm circuit, and the wireless communication module are respectively connected to the main processor; Take the power circuit and connect it with the power module, and the power module supplies power to the device; The bus self-fetching power supply circuit includes a rectangular power-taking iron core and a voltage conditioning circuit; the input end of the rectangular power-taking iron core is wound around the bus bar, and the output end of the rectangular power-taking iron core is wound with a secondary coil, and the secondary coil is connected to the Voltage conditioning circuit connection; The voltage conditioning circuit includes an input voltage dividing resistor, a voltage comparator, a positive half cycle amplitude setting unit, a negative half cycle amplitude setting unit, a photoelectric coupling output unit, a thyristor electronic switch and a release resistor; the input voltage dividing resistor, the voltage comparator , the photoelectric coupling output unit, the thyristor electronic switch and the release resistor are connected in series in sequence to the power module, the voltage comparator is respectively connected to the positive half cycle amplitude setting unit and the negative half cycle amplitude setting unit, and the thyristor electronic switch is grounded. 2. The power grid transformer leakage fault monitoring device according to claim 1, characterized in that it also includes an instantaneous high voltage protection circuit, and the instantaneous high voltage protection circuit includes a shrapnel T, a varistor R2, a resistor R3, a resistor R4, and a rectifier bridge U1, filter capacitor C1, optocoupler U2, and indicator light L2, the shrapnel T, varistor R2 are connected in series with the power supply, the resistor R3 is connected in series with the rectifier bridge U1, and connected in parallel with the varistor R2, the filter The capacitor C1 is connected in series with the rectifier bridge U1, and the resistor R4, the indicator light L2 and the optocoupler U2 are connected in parallel with the filter capacitor C1. 3. The grid transformer leakage fault monitoring device according to claim 1 or 2, characterized in that, said alarm circuit resistance R1, triode Q1, relay K1, indicator light L1, buzzer Y; one end of resistance R1 is connected to the main processing The other end of the resistor R1 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the voltage source through the coil of the relay K1, and the contact of the relay K1 is connected to the serially connected indicator light L1 , buzzer Y. 4. The power grid transformer leakage fault monitoring device according to claim 1 or 2, characterized in that the wireless communication module is a GPRS module. 5. The power grid transformer leakage fault monitoring device according to claim 4, wherein the GPRS module is connected with a SIM card interface module. 6. The grid transformer leakage fault monitoring device according to claim 1 or 2, wherein the main processor is a STM32F103RET6 processor based on the Cortex-M3 core. 7. The power grid transformer leakage fault monitoring device according to claim 1 or 2, further comprising a storage module connected to the main processor. 8. The power grid transformer leakage fault monitoring device according to claim 1 or 2, further comprising a USB interface module connected to the main processor.