A kind of distribution transformer protective device
Technical field
The utility model belongs to the technical field of protecting electrical power system, relates in particular to a kind of distribution transformer protective device.
Background technology
At large size industrial enterprise and power plant a large amount of distribution transformers is arranged; these distribution transformers have disposed the distribution transformer protective device mostly; existing distribution transformer protective device all is the electric physical quantity by the distribution transformer that detects the collection of voltage transformer or current transformer; judge whether distribution transformer breaks down; if break down, the execute protection action.
Because the reason of work or environment, the temperature of distribution transformer can be very high, so also can cause distribution transformer to break down.
But existing distribution transformer protective device can't judge whether distribution transformer breaks down by detecting the scene temperature of distribution transformer.Such distribution transformer protective device can not provide comprehensive defencive function.
The utility model content
The purpose of this utility model is to provide a kind of distribution transformer protective device, is intended to solve the problem that present distribution transformer protective device exists can not provide the general protection function.
The utility model is achieved in that a kind of distribution transformer protective device, and described protective device comprises:
The electric physical quantity of the distribution transformer of voltage transformer or current transformer collection is converted to the first signal condition unit of analog detection signal;
With the low-pass filter unit that the described first signal condition unit is connected, the high order harmonic component in the filtering analog detection signal;
Described protective device also comprises:
The temperature amount of the distribution transformer of temperature sensor collection is converted to the secondary signal conditioning unit of analog temperature detection signal;
With described low-pass filter unit and the AD conversion unit that secondary signal conditioning unit is connected, described analog detection signal is converted to digital detection signal respectively, described analog temperature detection signal is converted to the digital temperature detection signal;
The electric physical quantity detecting unit that is connected with described AD conversion unit according to the electric physical quantity of the distribution transformer in the digital detection signal, detects described electric physical quantity and whether surpasses limit value, exports electric physical quantity testing result signal;
The temperature detecting unit that is connected with described AD conversion unit according to the temperature amount of the distribution transformer in the digital temperature detection signal, detects described temperature amount and whether surpasses limit value, output temperature testing result signal;
The control unit that is connected with temperature detecting unit with described electric physical quantity detecting unit respectively, according to described electric physical quantity testing result signal and temperature detection result signal, the output control signal; And
Be connected the relay of execute protection action with described control unit.
In the utility model; the distribution transformer protective device makes it judge whether distribution transformer breaks down by detecting the scene temperature of distribution transformer by secondary signal conditioning unit and temperature detecting unit are set; the execute protection action can provide comprehensive defencive function.
Description of drawings
Fig. 1 is the structure chart of the distribution transformer protective device that provides of the utility model embodiment.
Embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearer,, the utility model is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
Fig. 1 shows the structure of the distribution transformer protective device that the utility model embodiment provides, and for convenience of explanation, only shows the part relevant with the utility model.
The distribution transformer protective device that the utility model embodiment provides comprises: the first signal condition unit 100, low-pass filter unit 200, secondary signal conditioning unit 300, AD conversion unit 400, electric physical quantity detecting unit 500, temperature detecting unit 600, control unit 700, relay 800, communication unit 900 and display unit 1000.
The first signal condition unit 100 is converted to analog detection signal with the electric physical quantity of the distribution transformer of voltage transformer or current transformer collection; Low-pass filter unit 200 is connected the high order harmonic component in the filtering analog detection signal with the first signal condition unit 100; Secondary signal conditioning unit 300 is converted to the analog temperature detection signal with the temperature amount of the distribution transformer of temperature sensor collection; AD conversion unit 400 is connected with secondary signal conditioning unit 300 with low-pass filter unit 200 respectively, and analog detection signal is converted to digital detection signal, and the analog temperature detection signal is converted to the digital temperature detection signal; Electricity physical quantity detecting unit 500 is connected with AD conversion unit 400, according to the electric physical quantity of the distribution transformer in the digital detection signal, detects electric physical quantity and whether surpasses limit value, exports electric physical quantity testing result signal; Temperature detecting unit 600 is connected with AD conversion unit 400, and according to the temperature amount of the distribution transformer in the digital temperature detection signal, whether the detected temperatures amount surpasses limit value, output temperature testing result signal.
Control unit 700 is connected with temperature detecting unit 600 with electric physical quantity detecting unit 500 respectively, control unit 700 is according to electric physical quantity testing result signal, if electric physical quantity testing result signal indication electricity physical quantity surpasses limit value, control unit 700 output control signals are given relay 800, and relay 800 control distribution transformer switches disconnect or the warning circuit switch connection; Control unit 700 is according to the temperature detection result signal, if temperature detection result signal indication temperature amount surpasses limit value, control unit 700 output control signals disconnect or the warning circuit switch connection for relay 800 control distribution transformer switches.
As the utility model one embodiment, the block switch protective device also comprises: the communication unit 900 that is connected with control unit 700; And be connected with control unit 700, for the display unit 1000 of information interaction is provided between user and the distribution transformer protective device.
In the utility model embodiment; the distribution transformer protective device is by being provided with secondary signal conditioning unit and temperature detecting unit; make it can pass through to detect the scene temperature of distribution transformer; judge whether distribution transformer breaks down; the execute protection action can provide comprehensive defencive function.
The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all any modifications of within spirit of the present utility model and principle, being done, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.