Outlet pressing plate voltage induction device

Abstract

The invention discloses an outlet pressing plate voltage induction device which comprises an induction voltage acquisition module, a signal amplification module, an interference noise filtering module, a positive and negative polarity amplification module, a voltage amplitude stabilization module, an A / D converter, an operation processing module and a communication interface module. The induced voltage acquisition module is used for performing induced detection on voltage to ground at the lower end of an outlet pressing plate to obtain a weak induced voltage signal; the positive and negative polarity amplification module is used for performing voltage overturning on the alternating voltage signal according to the phase characteristics to obtain a fully positive or fully negative voltage signal with continuously changing amplitude; the voltage amplitude stabilization module is used for extracting peak voltage according to the voltage signal obtained by the positive and negative polarity amplification module to obtain stable direct current voltage; the A / D converter is used for converting the analog signal into a digital signal representing the loop voltage of the pressing plate. Operation and maintenance personnel of the transformer substation are helped to automatically monitor the state of the outlet pressing plate and whether the tripping and closing control loop is normal or not.

Description

Technical Field

[0001] The invention relates to the technical field of transformer substation relay protection outlet pressure plates, and more specifically, to an outlet pressure plate voltage sensing device. Background Art

[0002] The state of the relay protection outlet pressure plate of the substation and whether its control circuit is normal are key equipment to ensure the normal protection of the outlet. At present, the state of the relay protection outlet pressure plate is mainly realized by adding external sensors to detect its throw-in and throw-out position, mainly including magnetic induction sensor technology, micro switch detection technology, gyroscope detection technology, infrared detection technology, etc. The above scheme mainly solves the problem of the throw-in and throw-out position state of the outlet pressure plate, but it is impossible to fully monitor whether the tripping and closing control circuit where the outlet pressure plate is located is normal. For example, if the relay protection device outlet relay is stuck, the pressure plate is not allowed to be put into operation, otherwise it may cause the circuit breaker to trip. The tripping and closing control circuit usually uses DC positive and negative voltage. At present, the tripping and closing control circuit where the outlet pressure plate is located is mainly realized by manual measurement of a multimeter. This method has great safety hazards. For example, if the multimeter gear is used incorrectly, the circuit may be directly grounded and cause the circuit breaker to trip. Therefore, it is urgent to find a safe and reliable outlet pressure plate voltage sensing device to replace manual measurement and realize the complete monitoring of its outlet pressure plate state and circuit, so as to improve the safety level of relay protection operation and maintenance. Summary of the invention

[0003] The embodiment of the present invention provides an outlet pressure plate voltage sensing device. The present invention aims to provide an outlet pressure plate voltage sensing device. By sensing and detecting the voltage between the lower end of the outlet pressure plate and the ground, the outlet pressure plate state and the tripping and closing control circuit where it is located can be monitored online. The scheme adopts non-contact sensing technology and is completely electrically isolated from the circuit where the outlet pressure plate is located, without affecting the normal operation of the circuit. The detected voltage state is used for calculation to determine whether the outlet pressure plate state and the tripping and closing control circuit where it is located are normal. This helps the substation operation and maintenance personnel to automatically monitor the outlet pressure plate state and whether the tripping and closing control circuit where it is located is normal, improves the operation and maintenance efficiency, and enhances the safe operation level of the substation.

[0004] To achieve the above object, the present invention provides an outlet pressure plate voltage sensing device, comprising: an induced voltage acquisition module, a signal amplification module, an interference noise filtering module, a positive and negative polarity amplification module, a voltage amplitude stabilization module, an A / D converter, an operation processing module, and a communication interface module; The induced voltage acquisition module is used to sense the voltage at the lower end of the outlet pressure plate to the ground to obtain a weak induced voltage signal; A signal amplification module, used for amplifying the induced voltage signal; The interference noise filtering module is used to filter out the redundant interference signals to obtain a relatively pure alternating voltage signal; The positive and negative polarity amplification module is used to reverse the voltage of the alternating voltage signal according to the phase characteristics to obtain a fully positive or fully negative voltage signal with a continuously changing amplitude; The voltage amplitude stabilization module is used to extract the peak voltage according to the voltage signal obtained by the positive and negative polarity amplification module to obtain a stable DC voltage; The A / D converter is used to obtain a stable DC voltage and convert the analog signal into a digital signal representing the voltage of the pressure plate circuit; On the one hand, the operation and processing module controls the induced current acquisition device to obtain a stable alternating induced current to ensure the accuracy of the induction source. On the other hand, the operation and processing module processes the digital signal representing the pressure plate loop voltage transmitted by the A / D converter and sends the voltage information through the communication interface module.

[0005] Furthermore, the induced voltage acquisition module includes a motor, a shielding blade and a voltage sensor; the shielding blade is installed at the output end of the motor, and rotates to cut the electric field generated by the DC voltage of the pressure plate circuit to obtain a periodic alternating electric field, and obtains a periodic alternating induced voltage in the periodic alternating electric field. The voltage sensor is a non-contact voltage sensor, which is used to obtain an induced voltage signal based on the induced voltage.

[0006] Furthermore, the voltage sensor includes: a sensing electrode, the sensing electrode having a space for a measured conductor to pass through, an input coupling capacitor formed between the measured conductor and the sensing electrode, and a grounding impedance formed between the sensing electrode and the ground; at least one feedback conductor, the feedback conductor passes through the sensing electrode and forms a feedback coupling capacitor with the sensing electrode, and the feedback coupling capacitor is proportional to the input coupling capacitor.

[0007] Furthermore, the interference noise filtering module includes a common mode inductor and a filter capacitor, the positive electrode of the filter capacitor is connected to the positive signal input end of the common mode inductor, and the negative electrode of the filter capacitor is connected to the negative signal input end of the common mode inductor.

[0008] Furthermore, the positive and negative polarity amplification module includes a phase analysis device, a flip judgment module and a voltage flip branch; the phase analysis device is used to analyze the phase information of the current alternating voltage signal; the flip judgment module is used to preset a decision table for phase information and voltage flip decision and output a flip signal according to the decision table and the input phase information; the voltage flip path is used to flip the alternating voltage signal into a fully positive or fully negative voltage signal with a continuously changing amplitude.

[0009] Furthermore, the voltage amplitude stabilization module adopts a peak extraction circuit, and the peak extraction circuit includes: a voltage extraction circuit, a translation amplification circuit, a peak holding circuit and an RC discharge equivalent circuit; the voltage extraction circuit is used to proportionally reduce the voltage signal; the translation amplification circuit is used to translate the output signal of the voltage extraction circuit downward and amplify the signal related to the overvoltage peak; the peak holding circuit is used to extract the maximum value of the output signal of the translation amplification circuit; the RC discharge equivalent circuit is used to equivalent the peak value extracted by the peak holding circuit in the form of capacitor and resistor discharge time.

[0010] Furthermore, the A / D converter adopts ADC0804 analog-to-digital conversion chip.

[0011] Furthermore, the operation processing module adopts AT89S51 single chip microcomputer.

[0012] The present invention has the following beneficial effects: 1. The technology of the present invention determines the state of the pressure plate by collecting the voltages at the upper and lower ends of the pressure plate, thereby realizing the collection of the electrical connectivity state of the pressure plate circuit. It not only realizes the collection of the pressure plate's insertion and retraction state, but also can identify whether the contact of the pressure plate is good after it is put into use and whether there is any loose contact.

[0013] 2. This technology uses non-contact voltage sampling, which does not interfere with the operating circuit and avoids the risk of generating parasitic circuits.

[0014] 3. This technology can monitor the status of each key node of the operating circuit, ensure the effectiveness of the secondary circuit, prevent the failure of the protection action export, and improve the safety of the equipment.

[0015] 4. This technology effectively reduces the work efficiency of operation and maintenance personnel. It measures the voltage at the upper and lower ends of the pressure plate before and after the pressure plate is put in and out, and does not require operation and maintenance personnel to arrive at the site for operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0017] Figure 1 Schematic diagram of the working principle of an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] like Figure 1 As shown, an embodiment of the present invention provides an outlet pressure plate voltage sensing device, including: an induced voltage acquisition module, a signal amplification module, an interference noise filtering module, a positive and negative polarity amplification module, a voltage amplitude stabilization module, an A / D converter, an operation processing module, and a communication interface module.

[0022] The induction voltage acquisition module is used to sense the voltage between the lower end of the outlet pressure plate and the ground to obtain a weak induced voltage signal; the induced voltage acquisition module includes a motor, a shielding blade and a voltage sensor. The shielding blade is installed at the output end of the motor, and rotates to cut the electric field generated by the DC voltage of the pressure plate circuit to obtain a periodic alternating electric field, and obtains a periodic alternating induced voltage in the periodic alternating electric field. The voltage sensor is a non-contact voltage sensor, which is used to obtain an induced voltage signal based on the induced voltage. The voltage sensor includes: a sensing electrode, the sensing electrode has a space for the conductor to be measured to pass through, an input coupling capacitor is formed between the conductor to be measured and the sensing electrode, and a grounding impedance is formed between the sensing electrode and the ground; at least one feedback conductor, the feedback conductor passes through the sensing electrode, and forms a feedback coupling capacitor with the sensing electrodes, and the feedback coupling capacitor is proportional to the input coupling capacitor.

[0023] The signal amplification module is used to amplify the induced voltage signal.

[0024] The interference noise filtering module is used to filter out redundant interference signals to obtain a relatively pure alternating voltage signal; the interference noise filtering module includes a common mode inductor and a filter capacitor, the positive electrode of the filter capacitor is connected to the positive signal input end of the common mode inductor, and the negative electrode of the filter capacitor is connected to the negative signal input end of the common mode inductor.

[0025] The positive and negative polarity amplification module is used to perform voltage flipping on the alternating voltage signal according to the phase characteristics to obtain a fully positive or fully negative voltage signal with a continuously changing amplitude; the positive and negative polarity amplification module includes a phase analysis device, a flip judgment module and a voltage flip branch; the phase analysis device is used to analyze the phase information of the current alternating voltage signal; the flip judgment module is used to preset a decision table for phase information and voltage flip decision and output a flip signal according to the decision table and the input phase information; the voltage flip path is used to flip the alternating voltage signal into a fully positive or fully negative voltage signal with a continuously changing amplitude.

[0026] The voltage amplitude stabilization module is used to extract the peak voltage according to the voltage signal obtained by the positive and negative polarity amplification module to obtain a stable DC voltage; the voltage amplitude stabilization module adopts a peak extraction circuit, and the peak extraction circuit includes: a voltage extraction circuit, a translation amplification circuit, a peak holding circuit and an RC discharge equivalent circuit; the voltage extraction circuit is used to proportionally reduce the voltage signal; the translation amplification circuit is used to translate the output signal of the voltage extraction circuit downward and amplify the signal related to the overvoltage peak; the peak holding circuit is used to extract the maximum value of the output signal of the translation amplification circuit; the RC discharge equivalent circuit is used to equivalent the peak value extracted by the peak holding circuit in the form of capacitor and resistor discharge time.

[0027] The A / D converter is used to obtain a stable DC voltage and then convert the analog signal into a digital signal representing the voltage of the pressure plate loop; the A / D converter uses the ADC0804 analog-to-digital conversion chip.

[0028] On the one hand, the operation processing module controls the induction current acquisition device to obtain a stable alternating induction current to ensure the accuracy of the induction source. On the other hand, the operation processing module processes the digital signal representing the voltage of the pressure plate circuit transmitted by the A / D converter and sends the voltage information to the communication interface module. The operation processing module uses the AT89S51 single-chip microcomputer.

[0029] The embodiment of the present invention realizes online monitoring of the state of the outlet pressure plate and the tripping and closing control circuit where it is located by inductively detecting the voltage at the lower end of the outlet pressure plate to the ground. The scheme adopts non-contact induction technology and is completely electrically isolated from the circuit where the outlet pressure plate is located, without affecting the normal operation of the circuit. The detected voltage state is used for calculation to determine whether the state of the outlet pressure plate and the tripping and closing control circuit where it is located are normal. This helps the substation operation and maintenance personnel to automatically monitor the state of the outlet pressure plate and whether the tripping and closing control circuit where it is located is normal, improves the operation and maintenance efficiency, and enhances the safe operation level of the substation.

[0030] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An outlet pressure plate voltage sensing device, characterized in that: include: Induction voltage acquisition module, signal amplification module, interference noise filtering module, positive and negative polarity amplification module, voltage amplitude stabilization module, A / D converter, operation processing module, communication interface module; The induced voltage acquisition module is used to sense the voltage at the lower end of the outlet pressure plate to the ground to obtain a weak induced voltage signal; A signal amplification module, used for amplifying the induced voltage signal; The interference noise filtering module is used to filter out the redundant interference signals to obtain a relatively pure alternating voltage signal; The positive and negative polarity amplification module is used to reverse the voltage of the alternating voltage signal according to the phase characteristics to obtain a fully positive or fully negative voltage signal with a continuously changing amplitude; The voltage amplitude stabilization module is used to extract the peak voltage according to the voltage signal obtained by the positive and negative polarity amplification module to obtain a stable DC voltage; The A / D converter is used to obtain a stable DC voltage and convert the analog signal into a digital signal representing the voltage of the pressure plate circuit; On the one hand, the operation and processing module controls the induced current acquisition device to obtain a stable alternating induced current to ensure the accuracy of the induction source. On the other hand, the operation and processing module processes the digital signal representing the pressure plate loop voltage transmitted by the A / D converter and sends the voltage information through the communication interface module.

2. The outlet pressure plate voltage sensing device according to claim 1, characterized in that: The induced voltage acquisition module includes a motor, a shielding blade and a voltage sensor; the shielding blade is installed at the output end of the motor, and rotates to cut the electric field generated by the DC voltage of the pressure plate circuit to obtain a periodic alternating electric field, and obtains a periodic alternating induced voltage in the periodic alternating electric field. The voltage sensor is a non-contact voltage sensor, which is used to obtain an induced voltage signal based on the induced voltage.

3. The outlet pressure plate voltage sensing device according to claim 2, characterized in that: The voltage sensor comprises: a sensing electrode, the sensing electrode having a space for a measured conductor to pass through, an input coupling capacitor formed between the measured conductor and the sensing electrode, and a grounding impedance formed between the sensing electrode and the ground; and at least one feedback conductor, the feedback conductor passes through the sensing electrode and forms a feedback coupling capacitor with the sensing electrode, and the feedback coupling capacitor is proportional to the input coupling capacitor.

4. The outlet pressure plate voltage sensing device according to claim 1, characterized in that: The interference noise filtering module includes a common mode inductor and a filter capacitor, the positive electrode of the filter capacitor is connected to the positive signal input end of the common mode inductor, and the negative electrode of the filter capacitor is connected to the negative signal input end of the common mode inductor.

5. The outlet pressure plate voltage sensing device according to claim 1, characterized in that: The positive and negative polarity amplification module includes a phase analysis device, a flip judgment module and a voltage flip branch; the phase analysis device is used to analyze the phase information of the current alternating voltage signal; the flip judgment module is used to preset a decision table for phase information and voltage flip decision and output a flip signal according to the decision table and the input phase information; the voltage flip path is used to flip the alternating voltage signal into a fully positive or fully negative voltage signal with a continuously changing amplitude.

6. The outlet pressure plate voltage sensing device according to claim 1, characterized in that: The voltage amplitude stabilization module adopts a peak extraction circuit, which includes: a voltage extraction circuit, a translation amplification circuit, a peak holding circuit and an RC discharge equivalent circuit; the voltage extraction circuit is used to proportionally reduce the voltage signal; the translation amplification circuit is used to translate the output signal of the voltage extraction circuit downward and amplify the signal related to the overvoltage peak; the peak holding circuit is used to extract the maximum value of the output signal of the translation amplification circuit; the RC discharge equivalent circuit is used to equivalent the peak value extracted by the peak holding circuit in the form of capacitor and resistor discharge time.

7. The outlet pressure plate voltage sensing device according to claim 1, characterized in that: The A / D converter adopts ADC0804 analog-to-digital conversion chip.

8. The outlet pressure plate voltage sensing device according to claim 1, characterized in that: The operation processing module adopts AT89S51 single chip microcomputer.

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