CN212905110U - Voltage transformer isolating device - Google Patents
Voltage transformer isolating device Download PDFInfo
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- CN212905110U CN212905110U CN202022243546.3U CN202022243546U CN212905110U CN 212905110 U CN212905110 U CN 212905110U CN 202022243546 U CN202022243546 U CN 202022243546U CN 212905110 U CN212905110 U CN 212905110U
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Abstract
The utility model belongs to the technical field of electrical isolation, and particularly discloses a voltage transformer isolation device, which comprises an input module, a high-voltage photoelectric isolation device and an output module; the input module comprises a first proportional operational amplifier circuit, an AD conversion device and a high-frequency signal generator; the output module comprises a second proportional operational amplifier circuit and a DA converter, the analog quantity of the voltage transformer outputs a voltage digital signal after passing through the first proportional operational amplifier circuit and the AD converter, the voltage digital signal outputs a digital signal after passing through the high-voltage photoelectric isolation device, the DA converter and the AD converter only keep signal communication and do not directly generate electric communication, and the digital signal is output to the transformer substation measurement protection equipment after passing through the second proportional operational amplifier circuit. The input module and the output module are electrically isolated through the high-voltage photoelectric isolation device, any voltage or current interference of the input module cannot be transmitted into the output module through electrical connection, and the measurement and control protection equipment of the transformer substation cannot be damaged.
Description
Technical Field
The utility model belongs to the technical field of electrical isolation, a voltage transformer isolating device is related to.
Background
Compared with an electromagnetic transformer, the direct current resistance-capacitance voltage division type voltage transformer has the advantages of simple structure, small volume, high cost performance, good output linearity, easiness in maintenance and the like, and is widely applied to medium-voltage and high-voltage power grids. But it also has the disadvantages of low insulating property, no saturation phenomenon, poor anti-interference property, etc. If the secondary output signal of the resistance-capacitance voltage division type mutual inductor is directly connected into the measurement and control protection equipment of the transformer substation, the secondary side of the transformer substation is likely to output strong voltage current to burn out the measurement and control protection equipment of the transformer substation due to insulation or damage of devices and the like.
The existing electric isolation measures mainly comprise two measures, wherein one measure is isolated based on a direct-current isolation operational amplifier. The second type uses mainly linear optocouplers or isolation by frequency conversion of the optocouplers. The two isolation modes have obvious defects, and the first mode of using the direct-current isolation operational amplifier cannot achieve complete electrical isolation, cannot completely block interference output, and only can inhibit or reduce interference. The second kind uses the linear opto-coupler or the opto-coupler frequency conversion hardly accomplish to satisfy the characteristics that the precision is high, frequency response is fast, isolation voltage is big simultaneously.
SUMMERY OF THE UTILITY MODEL
In order to overcome the defects existing in the prior art, the utility model aims to provide a voltage transformer isolating device is divided into two big modules of input and output with voltage isolating device, and two modules are electrical isolation, can not damage the observing and controlling protective equipment of transformer substation.
The utility model discloses a realize through following technical scheme:
a voltage transformer isolation device comprises an input module, a high-voltage photoelectric isolation device and an output module;
the input module comprises a first proportional operational amplifier circuit, an AD conversion device and a high-frequency signal generator; the first proportional operational amplifier circuit is connected with the voltage transformer and used for carrying out proportional amplification on a stable voltage analog signal output by the voltage transformer to obtain a voltage analog signal;
the AD conversion device is connected with the proportional operational amplifier circuit and used for converting the voltage analog signal into a voltage digital signal and outputting the voltage digital signal and a sampling completion signal;
the high-frequency signal generator is connected with the AD conversion device and used for generating high-frequency pulses and starting the AD conversion device to collect signals;
the AD conversion device is connected with the DA conversion device through the high-voltage photoelectric isolation device and used for cutting off an interference channel and transmitting a voltage digital signal output by the AD and a signal after the AD is adopted to the DA conversion device;
the output module comprises a second proportional operational amplifier circuit and a DA conversion device, the DA conversion device is connected with the high-voltage photoelectric isolation device, the collected signal is used as an enabling signal of the DA conversion device, and the DA conversion device is used for converting the digital signal into an analog signal;
the second proportional operational amplifier circuit is connected with the DA conversion device and used for amplifying the analog signal and outputting an amplified analog signal; and the amplified analog signal is input to the transformer substation measurement protection equipment.
The input module further comprises a first protection device, the voltage transformer is connected with the first proportional operational amplifying circuit through the first protection device, and the first protection device is used for suppressing overvoltage and overcurrent interference of the input voltage analog signal, obtaining a stable voltage analog signal and inputting the stable voltage analog signal into the first proportional operational amplifying circuit.
Further, the first protection device adopts TVS and piezoresistor.
Furthermore, the output module also comprises a second protection device, the second proportional operation amplifying circuit is connected with the transformer substation measurement protection equipment through the second protection device, and the second protection device is used for inhibiting overvoltage and overcurrent interference of the output voltage analog signal and outputting a stable analog signal.
Further, the second protection device adopts TVS or piezoresistor.
Further, the input module is connected with a first switch power supply, and the first switch power supply is used for supplying power to the input module;
the output module is connected with a second switching power supply, and the second switching power supply is used for supplying power to the output module.
Further, the model of the AD conversion device is AD 574.
Further, the model of the DA conversion device is AD 667.
Furthermore, the model of the high-voltage photoelectric isolation device is GO133, and the isolation voltage between the inlet and the outlet is larger than 10 kV.
Compared with the prior art, the utility model discloses following profitable technological effect has:
the utility model discloses a voltage transformer isolation device, which comprises an input module, a high-voltage photoelectric isolation device and an output module; the input module comprises a first proportional operational amplifier circuit, an AD conversion device and a high-frequency signal generator; the output module comprises a second proportional operational amplifier circuit and a DA converter, the analog quantity of the voltage transformer is processed by the first protection device, the first proportional operational amplifier circuit and the AD converter, a voltage digital signal is output, the voltage digital signal is output to the DA converter after passing through the high-voltage photoelectric isolation device, the input module is electrically isolated from the output module, and the analog quantity output by the DA converter is output to the transformer substation measurement protection equipment after passing through the second proportional operational amplifier circuit and the second protection device. The input module and the output module are electrically isolated through the high-voltage photoelectric isolation device, any voltage or current interference of the input module cannot be transmitted into the output module through electrical connection, and the measurement and control protection equipment of the transformer substation cannot be damaged. The output precision is high, and frequency response is high, uses AD and DA, and the module can finely tune the analog quantity to proportion fortune, guarantees that input module and output module conversion precision are high, uses high frequency signal generator to start AD conversion device and gathers, and AD conversion device gathers and finishes the back and starts DA conversion device, guarantees that isolating device has good frequency response. The isolating device has the advantages of simple structure and high reliability, only AD and DA devices are used without CPU devices such as a single chip microcomputer, the program crash can not occur, good wiring and reasonable arrangement of the structure are realized through the circuit board, the isolating device can have very good anti-interference performance, and the operation reliability is high.
Furthermore, the input module and the output module are two completely independent switch power supplies, and the input module and the output module are connected only through a high-voltage photoelectric isolation device and are completely electrically isolated.
Furthermore, the input module further comprises a first protection device, the voltage transformer is connected with the first proportional operational amplifying circuit through the first protection device, and the first protection device can inhibit overvoltage and overcurrent interference and provide a more stable voltage analog signal.
Furthermore, the output module also comprises a second protection device, the second protection device is connected with the second proportional operational amplification circuit, and the second protection device can inhibit overvoltage and overcurrent interference and provide more stable analog signals.
Drawings
Fig. 1 is a schematic block diagram of the voltage transformer isolating device of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings:
as shown in fig. 1, the utility model discloses a voltage transformer isolation device, which comprises an input module, a high-voltage photoelectric isolation device and an output module; the input module comprises a first proportional operational amplifier circuit, an AD conversion device and a high-frequency signal generator; the first proportional operational amplifier circuit is connected with the voltage transformer and used for amplifying the stable voltage analog signal output by the voltage transformer to obtain an amplified voltage analog signal; the AD conversion device is connected with the proportional operation amplifying circuit and used for converting the amplified voltage analog signal into a voltage digital signal and outputting the voltage digital signal and a sampling completion signal; the high-frequency signal generator is connected with the AD conversion device and used for generating high-frequency pulses and starting the AD conversion device to collect signals; the high-voltage photoelectric isolation device is connected with the AD conversion device and used for cutting off an interference channel and transmitting the voltage digital signal output by the AD and the adopted signal to the DA device.
The output module comprises a second proportional operational amplifier circuit and a DA conversion device, the DA conversion device is connected with the high-voltage photoelectric isolation device, the collected signal is used as an enabling signal of the DA conversion device, and the DA conversion device is used for converting the digital signal into an analog signal; the second proportional operational amplifier circuit is connected with the DA conversion device and used for amplifying the analog signal and outputting an amplified analog signal; and the amplified analog signal is input to the transformer substation measurement protection equipment.
The utility model discloses divide into two big modules of input and output with voltage isolation device, two modules are electrical isolation completely, use AD conversion device and DA conversion device to carry out analog quantity and digital conversion, use high frequency signal generator to start the collection, guarantee the high frequency response.
Preferably, the input module further comprises a first protection device, the voltage transformer is connected with the first proportional operational amplifying circuit through the first protection device, the first protection device is used for protecting the voltage analog signal, suppressing overvoltage and overcurrent interference, obtaining a stable voltage analog signal, and inputting the stable voltage analog signal into the first proportional operational amplifying circuit.
Preferably, the output module further comprises a second protection device, the second protection device is connected with the second proportional operational amplifier circuit, and the second protection device is used for suppressing overvoltage and overcurrent interference of the output voltage analog signal and outputting a stable analog signal.
Generally, the first protection device and the second protection device employ a transient diode or a varistor. The transient diode is called TVS for short, and is a high-efficiency protective device in the form of a diode, when two poles of the TVS are impacted by reverse transient high energy, the TVS can change high impedance between the two poles into low impedance at the speed of 10 to the power of minus 12 seconds, absorb surge power of thousands of watts, clamp the voltage between the two poles at a preset value, and effectively protect precise components in an electronic circuit from being damaged by various surge pulses.
The voltage-limiting type protection device is a voltage-limiting type protection device, the nonlinear characteristic of the voltage-limiting type protection device is mainly utilized in circuit protection, when overvoltage appears between two poles of the voltage-limiting type protection device, the voltage-limiting type protection device can clamp the voltage to a relatively fixed voltage value, and therefore protection of a post-stage circuit is achieved.
The input module and the output module are two completely independent switch power supplies, which specifically are as follows: the input module is connected with a first switch power supply, and the first switch power supply is used for supplying power to the input module; the output module is connected with a second switching power supply, and the second switching power supply is used for supplying power to the output module.
Specifically, the model number of the AD conversion device is AD574, and the model number of the DA conversion device is AD 667.
The model of the high-voltage photoelectric isolation device is GO133, the isolation voltage between the inlet and the outlet of the high-voltage photoelectric isolation device is larger than 10kV, and the requirement of interference resistance in a medium-low voltage power system is met.
Explain with resistance-capacitance partial pressure formula direct current voltage transformer as an example, the utility model discloses a voltage transformer isolating device concrete signal processing process does:
step 1, a resistor-capacitor voltage division type direct current voltage transformer divides high voltage through a resistor R1 and a resistor R2 and outputs a small signal voltage analog signal to a first protection device, and overvoltage and overcurrent interference is suppressed through the protection device;
step 2, the voltage analog signal enters an AD conversion device after passing through a first proportional operation amplifying circuit;
3, generating high-frequency pulses by a high-frequency signal generator to start an AD conversion device to collect signals, and ensuring the high sampling rate of the AD conversion device so that the isolation device has good frequency response;
step 4, the AD conversion device converts the acquired analog quantity into a digital quantity and a sampling completion signal, and then the digital quantity and the sampling completion signal are transmitted to the DA conversion device through the high-voltage photoelectric isolation device;
step 5, the DA conversion device takes the AD acquisition finished signal as an enabling signal and converts the digital quantity into the analog quantity;
and 7, outputting the analog quantity output by the DA conversion device to the measurement and control protection equipment of the transformer substation through a second proportional operation amplifying circuit and a second protection device.
Claims (9)
1. A voltage transformer isolation device is characterized by comprising an input module, a high-voltage photoelectric isolation device and an output module;
the input module comprises a first proportional operational amplifier circuit, an AD conversion device and a high-frequency signal generator; the first proportional operational amplifier circuit is connected with the voltage transformer and used for carrying out proportional amplification on a stable voltage analog signal output by the voltage transformer to obtain a voltage analog signal;
the AD conversion device is connected with the proportional operational amplifier circuit and used for converting the voltage analog signal into a voltage digital signal and outputting the voltage digital signal and a sampling completion signal;
the high-frequency signal generator is connected with the AD conversion device and used for generating high-frequency pulses and starting the AD conversion device to collect signals;
the AD conversion device is connected with the DA conversion device through the high-voltage photoelectric isolation device and used for cutting off an interference channel and transmitting a voltage digital signal output by the AD and a signal after the AD is adopted to the DA conversion device;
the output module comprises a second proportional operational amplifier circuit and a DA conversion device, the DA conversion device is connected with the high-voltage photoelectric isolation device, the collected signal is used as an enabling signal of the DA conversion device, and the DA conversion device is used for converting the digital signal into an analog signal;
the second proportional operational amplifier circuit is connected with the DA conversion device and used for amplifying the analog signal and outputting an amplified analog signal; and the amplified analog signal is input to the transformer substation measurement protection equipment.
2. The voltage transformer isolating device according to claim 1, wherein the input module further comprises a first protection device, the voltage transformer is connected with the first proportional operational amplifying circuit through the first protection device, the first protection device is used for suppressing overvoltage and overcurrent interference of an input voltage analog signal to obtain a stable voltage analog signal, and the stable voltage analog signal is input into the first proportional operational amplifying circuit.
3. The voltage transformer isolation device of claim 2, wherein the first protection device comprises a TVS and a varistor.
4. The voltage transformer isolating device according to claim 1, wherein the output module further comprises a second protection device, the second proportional operational amplifier circuit is connected with the substation measurement protection device through the second protection device, and the second protection device is used for suppressing overvoltage and overcurrent interference of the output voltage analog signal and outputting a stable analog signal.
5. The voltage transformer isolating device according to claim 4, wherein the second protection device is TVS or a voltage dependent resistor.
6. The voltage transformer isolation device of claim 1, wherein the input module is connected to a first switching power supply, the first switching power supply being configured to supply power to the input module;
the output module is connected with a second switching power supply, and the second switching power supply is used for supplying power to the output module.
7. The voltage transformer isolating device according to claim 1, wherein the AD converter device is AD 574.
8. The voltage transformer isolating device according to claim 1, wherein the model of the DA conversion device is AD 667.
9. The isolation device of claim 1, wherein the high voltage optoelectronic isolation device is of type GO133, and the in-out isolation voltage is greater than 10 kV.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022243546.3U CN212905110U (en) | 2020-10-10 | 2020-10-10 | Voltage transformer isolating device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022243546.3U CN212905110U (en) | 2020-10-10 | 2020-10-10 | Voltage transformer isolating device |
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| Publication Number | Publication Date |
|---|---|
| CN212905110U true CN212905110U (en) | 2021-04-06 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202022243546.3U Active CN212905110U (en) | 2020-10-10 | 2020-10-10 | Voltage transformer isolating device |
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| CN (1) | CN212905110U (en) |
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- 2020-10-10 CN CN202022243546.3U patent/CN212905110U/en active Active
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