CN203149025U - Transient overvoltage monitoring system - Google Patents

Abstract

The utility model discloses a transient overvoltage monitoring system, which is externally connected to a bus bar and includes a high-voltage pulse voltage divider, an attenuator, a pre-signal processing circuit, a data acquisition card and a computer, wherein: the high-voltage pulse voltage divider, the attenuator The device, the pre-signal processing circuit, the data acquisition card and the computer are connected in sequence; the high-voltage pulse voltage divider is connected to the bus and grounded. The utility model can take into account the collection of internal and external overvoltages, realize the monitoring of internal and external overvoltages, and has short response time, fast collection speed and high sampling accuracy.

Description

A Transient Overvoltage Monitoring System

technical field

The utility model relates to a transient overvoltage monitoring system.

Background technique

The transient phenomenon is manifested as the transition from one stable state to another, and it can also be said that the system changes from one energy distribution method to another energy distribution method. In power systems, the most prominent disturbances that cause transient phenomena are tripping of a circuit breaker or a switching device, short circuits, ground faults, or lightning strikes. Power system overvoltage is a transient phenomenon of abnormal voltage rise exceeding the normal working voltage in the power system under certain conditions. In terms of its fundamental origin, it can be divided into two types, namely external overvoltage and internal overvoltage. Overvoltage.

External overvoltage is also called lightning overvoltage or atmospheric overvoltage. Its duration is extremely short, about 50-80μs, and the amplitude of the maximum lightning current reaches more than 200kA. It has pulse characteristics and is called lightning shock wave. Lightning overvoltage is an abnormal rise in grid voltage caused by thundercloud discharge. The characteristics of lightning overvoltage are: short duration, large amplitude, and great harm.

Internal overvoltages are caused by energy conversion or transfer within the power system. Since the energy of the internal overvoltage comes from the grid itself, its amplitude is basically proportional to the power frequency phase voltage of the grid. Usually, the ratio of the amplitude of the internal overvoltage to the maximum operating phase voltage amplitude of the grid is called internal Overvoltage multiple to represent the level of internal overvoltage.

The generation of overvoltage in the power system is random, and the internal and external overvoltages have different characteristics: the internal overvoltage spectrum is very wide, usually from tens of hertz to several thousand hertz, and the external overvoltage has a steeper wave head and a large amplitude. high. The existing transient overvoltage monitoring system cannot take into account the collection of internal and external overvoltages, and has disadvantages such as: low data acquisition rate, slow frequency response, lack of large-capacity data storage function, low sampling accuracy, etc., which cannot meet the needs of existing technologies. requirements.

Contents of the invention

The purpose of this utility model is to provide a transient overvoltage monitoring system, which can take into account the acquisition of internal and external overvoltages, realize the monitoring of internal and external overvoltages, and has a shorter response time, faster acquisition speed and high Sampling precision.

The technical scheme for realizing the above-mentioned purpose is:

A transient overvoltage monitoring system, externally connected to a bus bar, including a high-voltage pulse voltage divider, an attenuator, a pre-signal processing circuit, a data acquisition card and a computer, wherein:

The high-voltage pulse divider, attenuator, pre-signal processing circuit, data acquisition card and computer are sequentially connected;

The high-voltage pulse voltage divider is connected to the bus and grounded.

In the above transient overvoltage monitoring system, the pre-signal processing circuit includes a filter, an operational amplifier, an A/D (analog/digital) converter and a microprocessor, wherein:

The filter, operational amplifier and A/D converter are connected in sequence;

The filter is connected to the attenuator;

The A/D converter is connected to the data acquisition card;

The microprocessor is connected to the operational amplifier.

In the above-mentioned transient overvoltage monitoring system, the data acquisition card and the computer are connected through a PCI (Peripheral Component Interconnect, peripheral component interconnection standard) bus.

The beneficial effects of the utility model are: the utility model has a shorter response time and a faster acquisition speed through the configuration of the high-voltage pulse voltage divider and the data acquisition card, and can take into account the acquisition of internal and external overvoltages, and realizes internal and external overvoltages. voltage monitoring. Moreover, the utility model has a simple structure and is easy to implement, and the self-made pre-signal processing circuit can realize signal amplification and regulation, so that the utility model has very high sampling accuracy.

Description of drawings

Fig. 1 is the structural representation of the transient overvoltage monitoring system of the present utility model;

Fig. 2 is a structural diagram of the pre-signal processing circuit in the utility model.

Detailed ways

The utility model will be further described below in conjunction with accompanying drawing.

Please refer to Fig. 1, the transient overvoltage monitoring system of the present utility model, the external busbars (A, B, C), including high-voltage pulse voltage divider 1, attenuator 2, pre-signal processing circuit 3, data acquisition card 4 and computer 5, wherein:

High-voltage pulse voltage divider 1, attenuator 2, pre-signal processing circuit 3, data acquisition card 4 and computer 5 are connected sequentially; wherein, data acquisition card 4 and computer 5 are connected through PCI bus 6;

The high-voltage pulse voltage divider 1 is connected to the bus bar and grounded, and the high-voltage pulse voltage divider 1 obtains a voltage signal, and the voltage signal passes through the attenuator 2 and the pre-signal processing circuit 3 in turn, and after being adjusted to a level suitable for the data acquisition card 4 to receive, It is converted into a digital signal and enters the data acquisition card 4, and then enters the computer 5 through the PCI bus 6, and is processed by the computer 5, including real-time waveform display, data storage and analysis, "reproduction" of overvoltage waveform, parameter calculation, time domain and frequency domain analysis, etc.;

Please refer to Fig. 2, pre-signal processing circuit 3 comprises filter 31, operational amplifier 32, A/D converter 33 and microprocessor 34, and filter 31, operational amplifier 32 and A/D converter 33 are connected in sequence; The device 31 is connected to the attenuator 2, and the signal attenuated by the attenuator 2 is filtered; the A/D converter 33 is connected to the data acquisition card 4; the microprocessor 34 is connected to the operational amplifier 32, and the microprocessor 34 regulates the amplification of the operational amplifier 32 multiple, making it suitable for the level received by the data acquisition card 4; the A/D converter 33 realizes the function of converting the analog signal into a digital signal.

In this embodiment, the model selected by the high-voltage pulse divider 1 is HRHG_CR; the model selected by the attenuator 2 is RY.03-AV; the model selected by the data acquisition card 4 is PEM10412 or the PCI-9112 data acquisition of Beijing Ammann Technology card; the model selected by the microprocessor 34 is S3F84K4-DH94; the bus is a high-voltage bus.

The above embodiments are only for illustrating the utility model, rather than limiting the utility model. Those skilled in the art can also make various transformations or modifications without departing from the spirit and scope of the utility model. Therefore, all equivalent technical solutions should also belong to the category of the present utility model, and should be defined by each claim.

Claims (3)

1. A transient overvoltage monitoring system, externally connected to the busbar, is characterized in that it comprises a high-voltage pulse voltage divider, an attenuator, a pre-signal processing circuit, a data acquisition card and a computer, wherein: The high-voltage pulse divider, attenuator, pre-signal processing circuit, data acquisition card and computer are sequentially connected; The high-voltage pulse voltage divider is connected to the bus and grounded. 2. The transient overvoltage monitoring system according to claim 1, wherein the pre-signal processing circuit includes a filter, an operational amplifier, an A/D converter and a microprocessor, wherein: The filter, operational amplifier and A/D converter are connected in sequence; The filter is connected to the attenuator; The A/D converter is connected to the data acquisition card; The microprocessor is connected to the operational amplifier. 3. The transient overvoltage monitoring system according to claim 1 or 2, wherein the data acquisition card and the computer are connected through a PCI bus.

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