Sensor broken line detection device and method

Abstract

The invention discloses a sensor broken line detection device and method. The device comprises a D / A module, a broken line detection module, an A / D module and a processor. The broken line detection module is electrically connected with a sensor to be detected; the D / A module is electrically connected with the broken line detection module and the processor, and is controlled by the processor to provide different reference voltages for the broken line detection module; the A / D module is electrically connected with the broken line detection module and the processor, and transmits the output voltage of the broken line detection module to the processor; the processor judges whether the sensor is disconnected or not according to the variable quantity between the different reference voltages and the variable quantity between the different output voltages; the output voltage corresponds to the reference voltage. The modification realizes the detection of the disconnection state of the sensor, and ensures the accuracy of the data of the sensor.

Description

Technical Field

[0001] The present invention relates to the field of power system detection, and in particular to a sensor disconnection detection device and method. Background Art

[0002] At present, in the power system data acquisition device, it is necessary to judge the fault point based on the collected sensor (voltage transformer and current transformer) signal value. This principle is based on the normal operation of the sensor. If the sensor is disconnected, the sampled data will not match the actual situation, resulting in an error in the fault point location. Therefore, in the power system data acquisition device, it is very important to detect the disconnection status of the sensor. Summary of the invention

[0003] The object of the present invention is to provide a sensor disconnection detection device and method to achieve real-time monitoring of the sensor disconnection state and ensure the authenticity of the sensor sampling data.

[0004] In order to solve the above technical problems, the present invention provides a sensor disconnection detection device, comprising a D / A module, a disconnection detection module, an A / D module, and a processor; The disconnection detection module is electrically connected to the sensor to be tested; The D / A module is electrically connected to the disconnection detection module and the processor respectively, and is controlled by the processor to provide different reference voltages for the disconnection detection module; The A / D module is electrically connected to the disconnection detection module and the processor respectively, and transmits the output voltage of the disconnection detection module to the processor; The processor determines whether the sensor is disconnected according to the variation between different reference voltages and the variation between different output voltages; the output voltage corresponds to the reference voltage.

[0005] According to the above scheme, the disconnection detection module includes an operational amplifier and a feedback resistor.

[0006] According to the above scheme, the inverting terminal of the operational amplifier is electrically connected to the sensor, the non-inverting terminal thereof is electrically connected to the D / A module, and the output terminal thereof is electrically connected to the A / D module.

[0007] According to the above scheme, the two ends of the feedback resistor are electrically connected to the inverting end and the output end of the operational amplifier respectively.

[0008] According to the above scheme, when the variation of the different output voltages is the same as the variation of the different reference voltages, the processor determines that the sensor is disconnected.

[0009] According to the above scheme, when the variation of different output voltages is greater than the variation of different reference voltages, the processor determines that the sensor is not disconnected.

[0010] The present invention also provides a sensor disconnection detection method, which is implemented based on the sensor disconnection detection device described above, and includes: S1, providing different reference voltages for the disconnection detection module through the D / A module; S2, obtaining different reference voltages output by the disconnection detection module through the A / D module; S3: Determine whether the sensor is disconnected based on the changes between different reference voltages and the changes between different output voltages According to the above scheme, step S3 includes: when the change amount of the different output voltages is the same as the change amount of the different reference voltages, judging that the sensor is broken; when the change amount of the different output voltages is greater than the change amount of the different reference voltages, judging that the sensor is not broken.

[0011] According to the above scheme, the disconnection detection module includes an operational amplifier and a feedback resistor.

[0012] According to the above scheme, the inverting end of the operational amplifier is electrically connected to the sensor, its non-inverting end is electrically connected to the D / A module, and its output end is electrically connected to the A / D module; the two ends of the feedback resistor are electrically connected to the inverting end and the output end of the operational amplifier respectively.

[0013] Beneficial Effects The present invention provides a common-mode reference voltage in the signal sampling loop of the sensor, which not only ensures the acquisition of normal working signals in the sensor, but also ensures that the device can quickly determine whether the sensor is in a disconnected state, thereby providing an effective solution for disconnection detection of power system data acquisition devices and avoiding safety hazards caused by errors in collected data due to sensor disconnection.

[0014] Furthermore, the disconnection detection module is only composed of an operational amplifier and a feedback resistor, and has a simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a sensor disconnection detection device according to Embodiment 1 of the present invention; Figure 2 The figure is a schematic diagram of a sensor disconnection detection device according to the first embodiment of the present invention detecting a sensor in a disconnection state. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0017] Embodiment 1: Refer to Figure 1 and Figure 2 , this embodiment discloses a sensor disconnection detection device, including a D / A module U3, a disconnection detection module, an A / D module U2, and a processor U4; The disconnection detection module is electrically connected to the sensor T1 to be measured; The D / A module U3 is electrically connected to the disconnection detection module and the processor U4 respectively, and is controlled by the processor U4 to provide different reference voltages Vref for the disconnection detection module; The A / D module U2 is electrically connected to the disconnection detection module and the processor U4 respectively, and transmits the output voltage Vout of the disconnection detection module to the processor; The processor U4 determines whether the sensor is disconnected according to the change amount between different reference voltages Vref and the change amount between different output voltages Vout; the output voltage Vout corresponds to the reference voltage Vref. Further, the disconnection detection module includes an operational amplifier U1 and a feedback resistor Rf; the inverting terminal of the operational amplifier U1 is electrically connected to the sensor T1, its non-inverting terminal is electrically connected to the D / A module U3, and its output terminal is electrically connected to the A / D module U2; both ends of the feedback resistor Rf are electrically connected to the inverting terminal and the output terminal of the operational amplifier U1 respectively.

[0018] Further, when the change amount of different output voltages Vout is the same as the change amount of different reference voltages Vref, the processor determines that the sensor is disconnected; when the change amount of different output voltages Vout is greater than the change amount of different reference voltages Vref, the processor determines that the sensor is not disconnected; For easy understanding, this embodiment is exemplified as follows: In this embodiment, based on the characteristics of the voltage transformer and current transformer in the sensor, the secondary end of the transformer can be equivalently a series current source IS and internal resistance Rs; The D / A module outputs two different reference voltages Vref: 0 and △Vref, which are used for normal working signal voltage and disconnection state detection; When the sensor is working normally, if Vref = 0, Vout1 = Is * Rf (by calculating Is = Vout1 / Rf, the current in the transformer can be obtained, and through the transformation ratio of the sensor, the current at the primary end of the sensor can be obtained), and when Vref = △Vref, Vout2 >> △Vref (Vout2 = △Vref (1 + Rf / Rs), since the internal resistance Rs of the transformer is much smaller than Rf, that is, Rs << Rf, so Vout2 is much larger than △Vref), at this time, it can be determined that the sensor is not in a disconnected state; When the sensor is disconnected, if Vref=0, Vout1=0 (at this time, the sensor module works normally, but the primary side of the sensor does not give a signal, that is, the situation is the same as when the secondary side of the sensor is 0, that is, Vout1=Is*Rf=0*Rf=0, and it is impossible to determine whether the sensor module is in a disconnected state), and when Vref=△Vref, Vout2=△Vref, then it can be determined that the sensor is in a disconnected state.

[0019] Embodiment 2: The principles of this embodiment are basically the same as those of the first embodiment. Based on the first embodiment, this embodiment discloses a sensor disconnection detection method. The method is implemented based on the sensor disconnection detection device described above, and includes: S1, providing different reference voltages for the disconnection detection module through the D / A module; S2, obtaining different reference voltages output by the disconnection detection module through the A / D module; S3. When the variation of the different output voltages is the same as the variation of the different reference voltages, it is determined that the sensor is disconnected; when the variation of the different output voltages is greater than the variation of the different reference voltages, it is determined that the sensor is not disconnected.

[0020] Furthermore, the disconnection detection module includes an operational amplifier U1 and a feedback resistor Rf; the inverting end of the operational amplifier U1 is electrically connected to the sensor T1, its non-inverting end is electrically connected to the D / A module U3, and its output end is electrically connected to the A / D module U2; the two ends of the feedback resistor Rf are electrically connected to the inverting end and the output end of the operational amplifier U1, respectively.

[0021] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, and two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0022] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sensor disconnection detection device, characterized in that: Including D / A module, disconnection detection module, A / D module, processor; The disconnection detection module is electrically connected to the sensor to be tested; The D / A module is electrically connected to the disconnection detection module and the processor respectively, and is controlled by the processor to provide different reference voltages for the disconnection detection module; The A / D module is electrically connected to the disconnection detection module and the processor respectively, and transmits the output voltage of the disconnection detection module to the processor; The processor determines whether the sensor is disconnected according to the variation between different reference voltages and the variation between different output voltages; the output voltage corresponds to the reference voltage.

2. The sensor disconnection detection device according to claim 1, characterized in that: The disconnection detection module includes an operational amplifier and a feedback resistor.

3. The sensor disconnection detection device according to claim 2, characterized in that: The inverting terminal of the operational amplifier is electrically connected to the sensor, the non-inverting terminal thereof is electrically connected to the D / A module, and the output terminal thereof is electrically connected to the A / D module.

4. The sensor disconnection detection device according to claim 2, characterized in that: The two ends of the feedback resistor are electrically connected to the inverting end and the output end of the operational amplifier respectively.

5. The sensor disconnection detection device according to claim 1, characterized in that: When the variation of the different output voltages is the same as the variation of the different reference voltages, the processor determines that the sensor is disconnected.

6. The sensor disconnection detection device according to claim 1, characterized in that: When the variation of the different output voltages is greater than the variation of the different reference voltages, the processor determines that the sensor is not disconnected.

7. A sensor disconnection detection method, characterized in that: The method is implemented based on the sensor disconnection detection device according to claim 1, and comprises: S1, providing different reference voltages for the disconnection detection module through the D / A module; S2, obtaining different reference voltages output by the disconnection detection module through the A / D module; S3. Determine whether the sensor is disconnected based on the variation between different reference voltages and the variation between different output voltages.

8. The sensor disconnection detection method according to claim 7, characterized in that: Step S3 includes: when the variation of the different output voltages is the same as the variation of the different reference voltages, judging that the sensor is disconnected; when the variation of the different output voltages is greater than the variation of the different reference voltages, judging that the sensor is not disconnected.

9. The sensor disconnection detection method according to claim 7, characterized in that: The disconnection detection module includes an operational amplifier and a feedback resistor.

10. The sensor disconnection detection method according to claim 9, characterized in that: The inverting terminal of the operational amplifier is electrically connected to the sensor, the non-inverting terminal thereof is electrically connected to the D / A module, and the output terminal thereof is electrically connected to the A / D module; the two ends of the feedback resistor are electrically connected to the inverting terminal and the output terminal of the operational amplifier respectively.

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