CN203385813U - CPLD-based single-phase ground fault indicator - Google Patents

Abstract

The utility model belongs to the field of fault detection of power distribution lines, in particular to a CPLD-based single-phase grounding fault indicator. Its technical solution is that the fault indicator includes a fault detection module, a control module, a fault display module and a power supply module; wherein, the fault detection module, the control module and the fault display module are connected in sequence; the power supply module is connected to the Control module connection. The beneficial effect of the utility model is that it overcomes the deficiencies in the prior art, its structural design is reasonable, it can effectively indicate short-circuit fault information and grounding fault information, especially it can accurately detect the grounding fault, give an alarm to the fault, and improve the distribution efficiency. The scheduling and management level of power grid automation ensures the safe, reliable and economical operation of the distribution network.

Description

A Single Phase Ground Fault Indicator Based on CPLD

technical field

The utility model belongs to the field of fault detection of power distribution lines, in particular to a CPLD-based single-phase grounding fault indicator.

Background technique

my country's 3-60kv distribution network widely adopts neutral point non-effective grounding mode to operate, and the most common faults on distribution lines of this voltage level are ground faults and short-circuit faults. The characteristics of short-circuit faults are obvious, easy to determine, and relatively easy to find, and they account for a small proportion of total faults. With the transformation of rural power grids and urban power grids in power systems, the probability of their occurrence is also greatly reduced. At present, most of the indicators used in my country to judge line fault sections are short-circuit line fault indicators, which have been widely used in power systems. They can indicate short-circuit sections of power lines and can help line patrol personnel to find The short-circuit fault point greatly shortens the time to restore power supply, thereby improving the reliability of power supply and creating considerable economic and social benefits. However, the short-circuit fault indicator cannot judge and indicate the ground fault, and the occurrence rate of the ground fault accounts for more than 75% of the total faults in the line. It can be seen that the fault detection, especially the detection technology for quickly detecting two kinds of faults, is considerable.

For fault detection, major domestic manufacturers have begun to study single-phase-to-ground fault detection on lines, and have successively launched some trial products, such as ground fault indicators and short-to-ground two-in-one fault indicators. Since the ground fault is a problem in terms of detection principle and implementation cost, the fault indicator mainly adopts analog circuit technology, the realization function is too simple, the detection fault type is too single, and the inspection personnel need to inspect the site, which has many limitations.

Contents of the invention

Aiming at the problem that the existing fault indicator mentioned in the background technology has single function and single fault detection type, the utility model proposes a single-phase ground fault indicator for CPLD.

A single-phase ground fault indicator based on CPLD, characterized in that, said fault indicator includes a fault detection module, a control module, a fault display module and a power supply module;

Wherein, the fault detection module, the control module and the fault display module are connected in sequence;

The power supply module is connected with the control module.

The fault detection module includes a short-circuit fault detection module and a ground fault detection module; the short-circuit fault detection module includes a conductive rubber, a sensor coil and a sampling circuit board; the ground fault detection module includes a conductive rubber, a sensor coil and a sampling circuit board; The conductive rubber and the sensor coil are respectively connected to the sampling circuit board.

The control module adopts complex programmable logic device CPLD.

The fault display module includes an LED indicator light and a fluorescent indicator board.

The fault indicator also includes a pillar and a fault indicator housing.

The power supply module is powered by a lithium battery.

The beneficial effect of the utility model is that it overcomes the deficiencies in the prior art, its structural design is reasonable, it can effectively indicate short-circuit fault information and grounding fault information, and it can especially accurately detect grounding faults, give alarms to faults, and improve distribution efficiency. The scheduling and management level of power grid automation ensures the safe, reliable and economical operation of the distribution network.

Description of drawings

Fig. 1 is a structural block diagram of a single-phase ground fault indicator in CPLD provided by the utility model;

Fig. 2 is a schematic diagram of the appearance of a single-phase ground fault indicator for CPLD provided by the utility model;

Fig. 3 is a complex programmable logic device CPLD signal processing block diagram of a single-phase ground fault indicator in CPLD provided by the utility model;

Among them, 1-pillar; 2-conductive rubber; 3-coil; 4-LED indicator light; 5-fluorescent sign; 6-fault indicator shell.

Detailed ways

The preferred embodiments will be described in detail below in conjunction with the accompanying drawings. It should be emphasized that the following descriptions are only illustrative, not intended to limit the scope of the present utility model and its application.

Fig. 1 is a structural block diagram of a single-phase ground fault indicator for CPLD provided by the utility model. In Fig. 1, the fault indicator includes a fault detection module, a control module, a fault display module and a power supply module; wherein, the fault detection module, the control module and the fault display module are connected in sequence; the power supply module is connected to the control module connection.

The fault detection module is used for collecting signals, sampling the collected signals, and then sending the sampled signals to the control module for fault judgment, and driving the fault display module for fault display.

Described control module adopts complex programmable logic device CPLD; What adopted is American ALTERA company MAX7000S series general-purpose programmable logic device EPM7128SLC84, and it has the advantages of high density, high speed, low power consumption, and this chip adopts 84 pin PLCC packages, It mainly includes three parts: programmable I/O unit, programmable array block (macrocell) and programmable internal wiring (PIA). In addition to the I/O voltage and output function, you can also choose whether to reduce the device For power consumption, select whether the output signal of each pin works in a high-speed state or an open-drain state, etc. The above functions of EPM7128SLC84 make it widely used in various logic circuits, such as logic control, data selection and switching, signal decoding, multi-channel triggers and multi-level counters, digital delayers, etc., considering its low power consumption The utility model digital fault indicator chooses this chip as the control module of the whole indicator, mainly using its logic control function to control the operation of the whole device. The CPLD is connected to the fault detection module and the fault display module respectively. After analyzing the fault information extracted from the fault detection module, according to the fault discrimination method, if the transient current suddenly increases and the phase voltage drops to zero, the line will be powered off after 10 seconds. It is judged as a short-circuit fault; if the transient current increases suddenly and the phase voltage data drops but is not zero, and after 3 seconds, the line does not stop power supply, it means that a ground fault occurs. In addition, the control module is connected with an external power supply and has manual and automatic reset functions.

The power supply module is powered by a lithium battery, and the battery is a 10-20Ah/6V lithium battery to provide power for the digital fault indicator.

Fig. 2 is a schematic diagram of the appearance of a single-phase ground fault indicator for CPLD provided by the present invention. In Fig. 2, the two pillars 1 act as fixed supports, the coil 3 is used to collect phase current data, the conductive rubber 2 is used to sense the change of the phase voltage, the lithium battery supplies power for the whole device, and the complex programmable logic device CPLD is used for the whole device. The controller, below are 4 bright LED indicators 4 and a fluorescent sign 5 for failure indication; the failure indicator also includes a failure indicator housing 6 for protecting the failure indicator.

Fig. 3 is a signal processing block diagram of a complex programmable logic device CPLD for a CPLD single-phase ground fault indicator provided by the utility model. In Figure 3, the fault detection module senses the changes of transient current and phase voltage through the conductive rubber and the coil respectively, and samples the obtained current and voltage signals through the sampling circuit board and sends them to the control module. To determine which kind of fault occurs, when the fault occurs, drive 4 bright LED indicators to flash and the fluorescent indicator to send an alarm signal.

The principle of fault detection: if the transient current increases suddenly and the phase voltage data is zero, and the line is powered off after 10 seconds, it means that a short circuit fault occurs; if the transient current increases suddenly and the phase voltage data drops but is not zero, and After 3 seconds without power failure on the line, it means that a ground fault has occurred.

1. Short-circuit alarm indication: the changes of phase current and phase voltage are sensed respectively by the coil and the conductive rubber. If the transient current increases suddenly and the phase voltage data is zero, the fault detection module will report this change to the control module and judge after 10 seconds If the phase voltage is zero and the line is powered off, it is a short circuit fault. At this time, the control module drives the LED light to flash (the LED light is on for 10ms and off for 2 seconds), and the fluorescent sign turns over to indicate the fault.

2. Grounding alarm indication: the changes of phase current and phase voltage are respectively induced by the coil and conductive rubber. If the transient current increases suddenly and the phase voltage data drops but is not zero, the fault detection module will report this change to the control module, and the control module will judge whether the line is powered off after 3 seconds. If the line is powered off, it means a ground fault. At this time, the control module drives the LED light to flash (the LED light is on for 10ms and off for 3 seconds), and the fluorescent sign turns over to indicate the fault.

3. Automatic reset: When the indicator generates an alarm and the line is in a power failure state,

Automatic reset within 1-24 hours (the fluorescent sign returns, and the LED light stops flashing), and after the line is powered on, it will automatically reset; when the line is charged, it will automatically reset within 30-60 minutes. And the reset time can be set before leaving the factory.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, and any person familiar with the technical field can easily think of All changes or replacements should fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (5)

1. the singlephase earth fault indicator based on CPLD, is characterized in that, described indicator comprises fault detection module, control module, fault display module and supply module;

Wherein, described fault detection module, control module and fault display module are connected in turn;

Described supply module is connected with described control module;

Described fault detection module comprises short trouble detection module and Earth Fault Detection module; Described short trouble detection module comprises conductive rubber, cell winding and sampling circuit board; Described Earth Fault Detection module comprises conductive rubber, cell winding and sampling circuit board; Described conductive rubber is connected with described sampling circuit board respectively with cell winding.

2. fault detector according to claim 1, is characterized in that, described control module adopts complex programmable logic device (CPLD).

3. fault detector according to claim 1, is characterized in that, described fault display module comprises LED light and fluorescent indicating panel.

4. fault detector according to claim 1, is characterized in that, described indicator also comprises pillar and fault detector shell.

5. fault detector according to claim 1, is characterized in that, described supply module adopts lithium battery power supply.

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