CN110208597B - Self-powered wireless current monitoring system based on single-winding current transformer - Google Patents
Self-powered wireless current monitoring system based on single-winding current transformer Download PDFInfo
- Publication number
- CN110208597B CN110208597B CN201910433058.8A CN201910433058A CN110208597B CN 110208597 B CN110208597 B CN 110208597B CN 201910433058 A CN201910433058 A CN 201910433058A CN 110208597 B CN110208597 B CN 110208597B
- Authority
- CN
- China
- Prior art keywords
- resistor
- module
- energy storage
- voltage
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000012544 monitoring process Methods 0.000 title claims abstract description 48
- 238000004804 winding Methods 0.000 title claims abstract description 45
- 238000004146 energy storage Methods 0.000 claims abstract description 105
- 238000005070 sampling Methods 0.000 claims abstract description 94
- 230000003750 conditioning effect Effects 0.000 claims abstract description 53
- 238000001914 filtration Methods 0.000 claims abstract description 47
- 230000005540 biological transmission Effects 0.000 claims abstract description 8
- 239000003990 capacitor Substances 0.000 claims description 72
- 239000003381 stabilizer Substances 0.000 claims description 23
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 14
- 229910052744 lithium Inorganic materials 0.000 claims description 14
- 238000006243 chemical reaction Methods 0.000 claims description 13
- 229920006395 saturated elastomer Polymers 0.000 claims description 8
- 230000001939 inductive effect Effects 0.000 claims description 3
- 238000012545 processing Methods 0.000 claims description 3
- 230000000087 stabilizing effect Effects 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 4
- 238000009499 grossing Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- 230000003321 amplification Effects 0.000 description 3
- 230000001965 increasing effect Effects 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 230000005674 electromagnetic induction Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
- G01R15/183—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using transformers with a magnetic core
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
-
- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C17/00—Arrangements for transmitting signals characterised by the use of a wireless electrical link
- G08C17/02—Arrangements for transmitting signals characterised by the use of a wireless electrical link using a radio link
-
- H02J5/005—
-
- H02J7/025—
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The invention discloses a self-powered wireless current monitoring system based on a single-winding current transformer, which comprises a collecting element and a monitoring circuit, wherein the monitoring circuit comprises a filtering rectification and current sampling module, a charging control and energy storage module and a signal conditioning module, the system comprises a microcontroller and a wireless transmitting module, wherein an acquisition element generates alternating current and outputs the alternating current to a filtering rectification and current sampling module, the filtering rectification and current sampling module generates direct current voltage and two paths of analog voltage signals to be output, a charging control and energy storage module supplies power to a signal conditioning module, the microcontroller and the wireless transmitting module, the signal conditioning module processes the two paths of analog voltage signals to obtain one path of analog voltage signal and outputs the analog voltage signal to the microcontroller, and the microcontroller monitors and controls the charging control and energy storage module to charge, generates a current monitoring signal and sends the current monitoring signal to the wireless transmitting module to carry out wireless transmission; the current transformer has the advantages that a conventional single-winding current transformer is adopted to simultaneously obtain electric energy and sense current, the cost is low, and the size is small.
Description
Technical Field
The invention relates to a self-powered wireless current monitoring system, in particular to a self-powered wireless current monitoring system based on a single-winding current transformer.
Background
At present, when measuring a large current of a power system, a current transformer based on an electromagnetic induction principle is generally adopted for realizing the measurement, the current transformer converts a large current on a primary side into a small current on a secondary side, and then a secondary instrument collects the small current on the secondary side of the current transformer through a cable. With the development of wireless sensor network technology, power monitoring equipment gradually tends to develop in a wireless direction, and a wireless current monitoring system is produced. The wireless current monitoring system can realize remote wireless real-time monitoring of the current of the power system and is widely applied.
The existing wireless current monitoring system mainly comprises a collecting element and a monitoring circuit, wherein the collecting element is a current transformer, and the monitoring circuit is composed of active devices such as a microcontroller and a wireless transmitting module. The current transformer is a passive device, the working process of the current transformer does not need to depend on external power supply, but active devices such as a microcontroller and a wireless transmitting module which form a monitoring circuit need to depend on external power supply in the working process. At present, there are two main schemes for providing power supply for monitoring circuits in a radio current monitoring system: the first scheme is that an extra dry battery is adopted to supply power for active devices such as a microcontroller, a wireless transmission module and the like, the endurance time of the dry battery is limited in the scheme, so that the dry battery is frequently replaced, and the replacement cost of the dry battery is high or even the dry battery cannot be replaced for equipment installed in remote areas and embedded environments; the second scheme is that electric energy is obtained from the primary side of the current transformer based on the electromagnetic induction principle of the current transformer, but the current transformer outputs alternating current, and active devices such as a microcontroller and a wireless transmitting module need stable direct current, so that a corresponding conversion circuit needs to be designed.
In recent years, the problem of power supply of wireless current monitoring systems has been widely studied. Chinese patent application No. CN201480008160.9 discloses a current transformation system in which a current transformer for detection and a current transformer for power generation are separately provided in parallel on a circuit, and an integrated system for managing the same through a wireless communication network. The scheme solves the problem of power supply of the wireless current monitoring system through self-power supply of the wireless current monitoring system. However, the current monitoring circuit and the electric energy acquisition circuit of the scheme are independent from each other, so that two single-winding current transformers are required to be adopted for implementing the scheme, wherein one single-winding current transformer is used for acquiring electric energy, and the other single-winding current transformer is used for sensing current, so that the volume of equipment is increased, and the application cost of the scheme is increased. Chinese patent application No. CN201811490262.5 discloses a passive wireless current sensor based on a dual-winding current transformer, which also solves the problem of power supply of a wireless current monitoring system through self-power supply of the wireless current monitoring system. However, since the current monitoring circuit and the power acquisition circuit of the solution are also independent of each other, the solution is implemented by using a dual-winding current transformer, wherein one winding of the dual-winding current transformer is used for power acquisition and the other winding is used for current sensing. However, the double-winding current transformer is more expensive than the single-winding current transformer, so that the solution will greatly increase the application cost.
Disclosure of Invention
The invention aims to solve the technical problem of providing a self-powered wireless current monitoring system based on a single-winding current transformer, wherein the self-powered wireless current monitoring system adopts a conventional single-winding current transformer to simultaneously acquire electric energy and sense current, and has the advantages of low cost and small volume.
The technical scheme adopted by the invention for solving the technical problems is as follows: a self-powered wireless current monitoring system based on a single-winding current transformer comprises an acquisition element and a monitoring circuit, wherein the acquisition element is realized by adopting a conventional single-winding current transformer, and the monitoring circuit comprises a filtering rectification and current sampling module, a charging control and energy storage module, a signal conditioning module, a microcontroller and a wireless transmitting module; the single-winding current transformer is used for inducing alternating current in a cable to be detected and then generating alternating current in a secondary side coil of the cable to be detected and outputting the alternating current to the filtering rectification and current sampling module, the filtering rectification and current sampling module firstly filters the alternating current input into the filtering rectification and current sampling module and then rectifies the alternating current to generate direct current voltage and outputs the direct current voltage to the charging control and energy storage module, the other side of the filtering rectification and current sampling module respectively samples a positive half cycle and a negative half cycle of the alternating current input into the filtering rectification and current sampling module to obtain two sampling signals, the two sampling signals are converted into two paths of analog voltage signals and output the two paths of analog voltage signals to the signal conditioning module, the charging control and energy storage module supplies power to the signal conditioning module, the microcontroller and the wireless transmitting module, and the signal conditioning module sequentially differentially amplifies the two paths of analog voltage signals input into the signal conditioning, And the microcontroller monitors the voltage of the charging control and energy storage module and controls the charging control and energy storage module to charge when the charging control and energy storage module is not saturated during charging, and performs analog-to-digital conversion on the analog voltage signal input into the microcontroller to obtain a digital signal, and then transmits the digital signal after processing to the wireless transmitting module for wireless transmission.
The filter rectification and current sampling module is provided with a first input end, a second input end, a positive sampling output end, a negative sampling output end and a direct current voltage output end, the charging control and energy storage module is provided with an input end, a first control end, a second control end, a positive voltage output end and a negative voltage output end, the microcontroller is provided with an input end, a first control end, a second control end and an output end, the signal conditioning module is provided with a positive input end, a negative input end and an output end, the first input end of the filter rectification and current sampling module is connected with one end of a secondary side coil of the single-winding current transformer, the second input end of the filter rectification and current sampling module is connected with the other end of the secondary side coil of the single-winding current transformer, the direct current voltage output end of the filter rectification and current sampling module is connected with the input end of the charging control and energy storage module, the positive sampling output end of the filtering rectification and current sampling module is connected with the positive input end of the signal conditioning module, the negative sampling output end of the filtering rectification and current sampling module is connected with the negative input end of the signal conditioning module, the output end of the signal conditioning module is connected with the input end of the microcontroller, the output end of the microcontroller is connected with the wireless transmitting module, the first control end of the microcontroller is connected with the first control end of the charging control and energy storage module, the second control end of the microcontroller is connected with the second control end of the charging control and energy storage module, the positive voltage output end and the negative voltage output end of the charging control and energy storage module output positive and negative power voltages to supply power for the signal conditioning module, the microcontroller and the wireless transmitting module, when the charging control and energy storage module is in a default state, the voltage of the first control end of the charging control and energy storage module is pulled down to a reference ground by the microcontroller, the voltage of the second control end of the charging control and energy storage module is pulled up to a high level by the microcontroller, the charging control and energy storage module performs voltage conversion on the direct current voltage connected to the input end of the charging control and energy storage module and then performs charging, the microcontroller performs real-time voltage monitoring on the charging control and energy storage module, when the charging control and energy storage module is detected to be saturated, the first control end of the microcontroller outputs a high level, so that the voltage of the first control end of the charging control and energy storage module is a high level, the second control end of the microcontroller outputs a low level, so that the voltage of the second control end of the charging control and energy storage module is a low level, and at the moment, the charging control and energy storage module stops charging.
The filtering, rectifying and current sampling module comprises a first capacitor, a second capacitor, a first inductor, a second inductor, a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode, a second diode, a third diode and a fourth diode; one end of the first capacitor, one end of the first inductor and one end of the first resistor are connected, the connection end of the first capacitor is the first input end of the filter rectification and current sampling module, one end of the second capacitor, one end of the second inductor and one end of the second resistor are connected, the connection end of the second capacitor is the second input end of the filter rectification and current sampling module, the other end of the first inductor, the other end of the first resistor, the anode of the first diode and the cathode of the third diode are connected, the other end of the second inductor, the other end of the second resistor, the anode of the second diode and the cathode of the fourth diode are connected, the cathode of the first diode is connected with the cathode of the second diode, and the connection end of the first diode is the dc voltage output end of the filter rectification and current sampling module, the positive pole of third diode with the one end of third resistance connect and its link does the positive sampling output of filtering rectification and current sampling module, the positive pole of fourth diode with the one end of fourth resistance connect and its link does the negative sampling output of filtering rectification and current sampling module, the other end of first electric capacity the other end of second electric capacity the other end of third resistance with the other end of fourth resistance connect and its link does the earthing terminal of filtering rectification and current sampling module, the earthing terminal of filtering rectification and current sampling module with consult ground and be connected. The filtering, rectifying and current sampling module is characterized in that two groups of LC filter circuits (a group of LC filter circuits consisting of a first inductor and a first capacitor and a group of LC filter circuits consisting of a second inductor and a second capacitor) are symmetrically arranged in an input channel of the full-bridge rectifying circuit, and two bridge arms of the full-bridge rectifying circuit are respectively connected with a sampling resistor (a third resistor and a fourth resistor) in series, so that three functions of filtering, rectifying and current sampling are integrated, and the circuit size is favorably reduced.
The charging control and energy storage module comprises a first NMOS (N-channel metal oxide semiconductor) tube, a third inductor, a fifth diode, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a first voltage regulator tube, a DC-DC (direct current-direct current) converter, a lithium battery, a positive voltage linear voltage stabilizer and a negative voltage linear voltage stabilizer; the DC-DC direct current converter is provided with an input end, an output end, a control end and a grounding end, the drain electrode of the first NMOS tube is connected with the anode of the fifth diode, the connecting end of the first NMOS tube is the input end of the charging control and energy storage module, the cathode of the fifth diode, one end of the third capacitor and the cathode of the first voltage stabilizing tube are connected with the input end of the DC-DC direct current converter, the output end of the DC-DC direct current converter, the anode of the lithium battery are connected with one end of the third inductor, the other end of the third inductor, one end of the fourth capacitor, the input end of the positive voltage linear voltage stabilizer are connected with the input end of the negative voltage linear voltage stabilizer, the output end of the positive voltage linear voltage stabilizer is connected with one end of the fifth capacitor, and the connecting end of the positive voltage linear voltage stabilizer is the positive voltage output end of the charging control and energy storage module, the output end of the negative voltage linear voltage stabilizer is connected with one end of the sixth capacitor, the connecting end of the negative voltage linear voltage stabilizer is the negative voltage output end of the charging control and energy storage module, the source electrode of the first NMOS tube, the other end of the third capacitor, the anode of the first voltage stabilizer tube, the grounding end of the DC-DC direct current converter, the cathode of the lithium battery, the other end of the fourth capacitor, the grounding end of the positive voltage linear voltage stabilizer, the grounding end of the negative voltage linear voltage stabilizer, the other end of the fifth capacitor and the other end of the sixth capacitor are connected, the connecting end of the fifth capacitor and the grounding end of the sixth capacitor are the grounding end of the charging control and energy storage module, the grounding end of the charging control and energy storage module is connected with a reference ground, the grid electrode of the first NMOS tube is the first control end of the charging control and energy storage module, and the control end of the DC-DC direct current converter is a second control end of the charging control and energy storage module.
The signal conditioning module comprises a first operational amplifier, a second operational amplifier, a third operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a seventh capacitor; the first operational amplifier, the second operational amplifier and the third operational amplifier are respectively provided with a positive input end, a negative input end, an output end, a positive power supply end and a negative power supply end, one end of a fifth resistor is the positive input end of the signal conditioning module, the other end of the fifth resistor, the positive input end of the first operational amplifier and one end of a sixth resistor are connected, one end of a seventh resistor is the negative input end of the signal conditioning module, the other end of the seventh resistor, the negative input end of the first operational amplifier and one end of an eighth resistor are connected, the other end of the eighth resistor, the output end of the first operational amplifier and one end of an eleventh resistor are connected, the other end of the eleventh resistor, the negative input end of the second operational amplifier and one end of a twelfth resistor are connected, the other end of the twelfth resistor, the output end of the second operational amplifier and the positive input end of the third operational amplifier are connected, one end of the ninth resistor, the positive power end of the first operational amplifier, the positive power end of the second operational amplifier and the positive power end of the third operational amplifier are connected, and the connection end of the ninth resistor is connected with the positive voltage output end of the charge control and energy storage module, the negative power end of the first operational amplifier, the negative power end of the second operational amplifier and the negative power end of the third operational amplifier are connected, and the connection end of the first operational amplifier, the negative power end of the second operational amplifier and the negative power end of the third operational amplifier is connected with the negative voltage output end of the charge control and energy storage module, the other end of the ninth resistor, the positive input end of the second operational amplifier and one end of the tenth resistor are connected, one end of the thirteenth resistor is connected with the negative input end of the third operational amplifier, the other end of the thirteenth resistor, the output end of the third operational amplifier and one end of the fourteenth resistor are connected, the other end of the fourteenth resistor is connected with one end of the seventh capacitor, the connection end of the fourteenth resistor is the output end of the signal conditioning module, and the other end of the sixth resistor, the other end of the tenth resistor and the other end of the seventh capacitor are all connected with a reference ground.
Compared with the prior art, the invention has the advantages that a monitoring circuit is formed by the filtering rectification and current sampling module, the charging control and energy storage module, the signal conditioning module, the microcontroller and the wireless transmitting module, the electric energy acquisition and current sensing are simultaneously realized by adopting a conventional single-winding current transformer, at the moment, after the single-winding current transformer senses the alternating current in the cable to be tested at the primary side, the alternating current is sensed in the closed secondary side coil of the single-winding current transformer according to the Faraday law of induction, so that the alternating current is generated and output to the filtering rectification and current sampling module, on one hand, the filtering rectification and current sampling module firstly filters and then rectifies the alternating current input into the filtering rectification and current sampling module to generate direct current voltage and output the direct current voltage to the charging control and energy storage module, on the other hand, the positive half cycle and the negative half cycle of the alternating current input into the filtering rectification, the two sampling signals are converted into two analog voltage signals to be output to the signal conditioning module, the charging control and energy storage module supplies power to the signal conditioning module, the microcontroller and the wireless transmitting module, the signal conditioning module sequentially carries out differential amplification, direct current bias and impedance conversion on the two analog voltage signals input into the signal conditioning module to generate one analog voltage signal to be output to the microcontroller, the microcontroller monitors the voltage of the charging control and energy storage module on one hand and controls the charging of the charging control and energy storage module when the charging of the charging control and energy storage module is not saturated, and on the other hand, carries out analog-to-digital conversion on the analog voltage signal input into the charging control and energy storage module to obtain a digital signal, and then transmits the digital signal to the wireless transmitting module for wireless transmission, therefore, the invention adopts a conventional single-winding current transformer to simultaneously carry out electric energy acquisition and current sensing without increasing the number of the current transformers, and a high-price current transformer with a plurality of secondary side coil windings is not required, and the circuit has the advantages of simple structure, low cost and small volume.
Drawings
FIG. 1 is a block diagram of a self-powered wireless current monitoring system based on a single winding current transformer of the present invention;
FIG. 2 is a circuit diagram of a filtering rectification and current sampling module of a self-powered wireless current monitoring system based on a single-winding current transformer according to the present invention;
FIG. 3 is a circuit diagram of a charge control and energy storage module of a self-powered wireless current monitoring system based on a single-winding current transformer according to the present invention;
fig. 4 is a circuit diagram of a signal conditioning module of a self-powered wireless current monitoring system based on a single-winding current transformer according to the present invention.
Detailed Description
The invention is described in further detail below with reference to the accompanying examples.
The first embodiment is as follows: as shown in fig. 1, a self-powered wireless current monitoring system based on a single-winding current transformer comprises an acquisition element and a monitoring circuit, wherein the acquisition element is realized by a conventional single-winding current transformer 1, and the monitoring circuit comprises a filtering rectification and current sampling module 2, a charging control and energy storage module 3, a signal conditioning module 4, a microcontroller 5 and a wireless transmitting module 6; the single-winding current transformer 1 is used for inducing alternating current in a cable to be tested and then generating alternating current in a secondary side coil of the cable to be tested and outputting the alternating current to a filtering rectification and current sampling module 2, the filtering rectification and current sampling module 2 firstly filters the alternating current input into the filtering rectification and current sampling module and then rectifies the alternating current to generate direct current voltage and outputs the direct current voltage to a charging control and energy storage module 3, the positive half cycle and the negative half cycle of the alternating current input into the filtering rectification and current sampling module are respectively sampled to obtain two sampling signals, the two sampling signals are converted into two paths of analog voltage signals and output to a signal conditioning module 4, the charging control and energy storage module 3 supplies power to the signal conditioning module 4, a microcontroller 5 and a wireless transmission module 6, the signal conditioning module 4 sequentially performs differential amplification, direct current bias and impedance conversion on the two paths of analog voltage signals input into the signal conditioning module 4 to generate one path of analog, the microcontroller 5 monitors the voltage of the charging control and energy storage module 3 on one hand, controls the charging control and energy storage module 3 to charge when the charging control and energy storage module 3 is not saturated, and on the other hand, performs analog-to-digital conversion on an analog voltage signal input into the microcontroller to obtain a digital signal, processes the digital signal and transmits the processed digital signal to the wireless transmitting module 6 for wireless transmission.
In this embodiment, the filtering, rectifying and current sampling module 2 has a first input terminal, a second input terminal, a positive sampling output terminal, a negative sampling output terminal and a dc voltage output terminal, the charging control and energy storage module 3 has an input terminal, a first control terminal, a second control terminal, a positive voltage output terminal and a negative voltage output terminal, the microcontroller 5 has an input terminal, a first control terminal, a second control terminal and an output terminal, the signal conditioning module 4 has a positive input terminal, a negative input terminal and an output terminal, the first input terminal of the filtering, rectifying and current sampling module 2 is connected with one end of the secondary side coil of the single-winding current transformer 1, the second input terminal of the filtering, rectifying and current sampling module 2 is connected with the other end of the secondary side coil of the single-winding current transformer 1, the dc voltage output terminal of the filtering, rectifying and current sampling module 2 is connected with the input terminal of the charging, the positive sampling output end of the filter rectification and current sampling module 2 is connected with the positive input end of the signal conditioning module 4, the negative sampling output end of the filter rectification and current sampling module 2 is connected with the negative input end of the signal conditioning module 4, the output end of the signal conditioning module 4 is connected with the input end of the microcontroller 5, the output end of the microcontroller 5 is connected with the wireless transmitting module 6, the first control end of the microcontroller 5 is connected with the first control end of the charging control and energy storage module 3, the second control end of the microcontroller 5 is connected with the second control end of the charging control and energy storage module 3, the positive voltage output end and the negative voltage output end of the charging control and energy storage module 3 output positive and negative power voltages to supply power to the signal conditioning module 4, the microcontroller 5 and the wireless transmitting module 6, when the charging control and energy storage module 3 is in a default state, the voltage of the first control end of the charging control and energy storage module 3 is pulled down to a reference ground by the microcontroller 5, the voltage of the second control end of the charging control and energy storage module 3 is pulled up to a high level by the microcontroller 5, the charging control and energy storage module 3 performs voltage conversion on the direct current voltage accessed by the input end of the charging control and energy storage module and then performs charging, the microcontroller 5 performs real-time voltage monitoring on the charging control and energy storage module 3, when the charging control and energy storage module 3 is detected to be saturated in charging, the first control end of the microcontroller 5 outputs the high level, the voltage of the first control end of the charging control and energy storage module 3 is enabled to be the high level, the second control end of the microcontroller 5 outputs the low level, the voltage of the second control end of the charging control and energy storage module 3 is enabled to be the low level, and the charging control and energy storage module 3 stops charging at the moment.
Example two: this embodiment is substantially the same as the first embodiment, with the following differences:
as shown in fig. 2, in the present embodiment, the filtering, rectifying and current sampling module 2 includes a first capacitor C1, a second capacitor C2, a first inductor L1, a second inductor L2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4; one end of a first capacitor C1, one end of a first inductor L1 and one end of a first resistor R1 are connected, the connection end of the first capacitor C2 is a first input end of the smoothing and rectifying and current sampling module 2, one end of a second capacitor C2, one end of a second inductor L2 and one end of a second resistor R2 are connected, the connection end of the second capacitor C2 is a second input end of the smoothing and rectifying and current sampling module 2, the other end of the first inductor L1, the other end of the first resistor R1, the anode of a first diode D1 and the cathode of a third diode D3 are connected, the other end of the second inductor L2, the other end of a second resistor R2, the anode of the second diode D2 and the cathode of a fourth diode D4 are connected, the cathode of the first diode D1 is connected with the cathode of the second diode D2, the connection end of the first diode D6332 is a DC voltage output end of the smoothing and rectifying and current sampling module 2, the anode of the third diode D3 is a connection end of the third resistor R3 and the positive connection end of the smoothing and current, the positive electrode of the fourth diode D4 is connected to one end of the fourth resistor R4, and the connection end thereof is the negative sampling output end of the smoothing rectification and current sampling module 2, the other end of the first capacitor C1, the other end of the second capacitor C2, the other end of the third resistor R3 and the other end of the fourth resistor R4 are connected, and the connection end thereof is the ground end of the smoothing rectification and current sampling module 2, and the ground end of the smoothing rectification and current sampling module 2 is connected to the ground reference.
As shown in fig. 3, in the present embodiment, the charging control and energy storage module 3 includes a first NMOS transistor M1, a third inductor L3, a fifth diode D5, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a first voltage regulator ZD1, a DC-DC converter, a lithium battery BAT, a positive voltage linear regulator, and a negative voltage linear regulator; the DC-DC direct current converter is provided with an input end, an output end, a control end and a grounding end, the drain electrode of a first NMOS tube M1 is connected with the positive electrode of a fifth diode D5, the connecting end of the drain electrode of the first NMOS tube M1 is the input end of the charging control and energy storage module 3, the negative electrode of the fifth diode D5, one end of a third capacitor C3, the negative electrode of a first voltage stabilizing tube ZD1 is connected with the input end of the DC-DC direct current converter, the output end of the DC-DC direct current converter, the positive electrode of a lithium battery BAT and one end of a third inductor L3 are connected, the other end of the third inductor L3, one end of a fourth capacitor C4, the input end of a positive voltage linear voltage stabilizer and the input end of a negative voltage linear voltage stabilizer are connected, the output end of the positive voltage linear voltage stabilizer is connected with one end of the fifth capacitor C5, the connecting end of the positive voltage output end of the charging control and energy storage module 3, the output, the source of the first NMOS transistor M1, the other end of the third capacitor C3, the positive electrode of the first voltage regulator ZD1, the ground terminal of the DC-DC converter, the negative electrode of the lithium battery BAT, the other end of the fourth capacitor C4, the ground terminal of the positive voltage linear regulator, the ground terminal of the negative voltage linear regulator, the other end of the fifth capacitor C5 and the other end of the sixth capacitor C6 are connected, and the connection terminal thereof is the ground terminal of the charging control and energy storage module 3, the ground terminal of the charging control and energy storage module 3 is connected with the reference ground, the gate of the first NMOS transistor M1 is the first control terminal of the charging control and energy storage module 3, and the control terminal of the DC-DC converter is the second control terminal of the charging control and energy storage module 3.
As shown in fig. 4, in the present embodiment, the signal conditioning module 4 includes a first operational amplifier OP1, a second operational amplifier OP2, a third operational amplifier OP3, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, and a seventh capacitor C7; the first operational amplifier OP1, the second operational amplifier OP2 and the third operational amplifier OP3 respectively have a positive input terminal, a negative input terminal, an output terminal, a positive power terminal and a negative power terminal, one end of the fifth resistor R5 is the positive input terminal of the signal conditioning module 4, the other end of the fifth resistor R5, the positive input terminal of the first operational amplifier OP1 and one end of the sixth resistor R6 are connected, one end of the seventh resistor R7 is the negative input terminal of the signal conditioning module 4, the other end of the seventh resistor R7, the negative input terminal of the first operational amplifier OP1 and one end of the eighth resistor R8 are connected, the other end of the eighth resistor R8, the output terminal of the first operational amplifier OP1 and one end of the eleventh resistor R11 are connected, the other end of the eleventh resistor R11, the negative input terminal of the second operational amplifier OP2 and one end of the twelfth resistor R12 are connected, the other end of the twelfth resistor R12, the output terminal of the second operational amplifier OP2 and the positive input terminal of the third operational amplifier OP3 are connected, one end of a ninth resistor R9, a positive power terminal of the first operational amplifier OP1, a positive power terminal of the second operational amplifier OP2 and a positive power terminal of the third operational amplifier OP3 are connected and a connection terminal thereof is connected with a positive voltage output terminal of the charge control and energy storage module 3, a negative power terminal of the first operational amplifier OP1, a negative power terminal of the second operational amplifier OP2 and a negative power terminal of the third operational amplifier OP3 are connected and a connection terminal thereof is connected with a negative voltage output terminal of the charge control and energy storage module 3, the other end of the ninth resistor R9, a positive input terminal of the second operational amplifier OP2 and one end of a tenth resistor R10 are connected, one end of a thirteenth resistor R13 is connected with a negative input terminal of the third operational amplifier OP3, the other end of the thirteenth resistor R13, an output terminal of the third operational amplifier OP3 and one end of a fourteenth resistor R14 are connected, the other end of the fourteenth resistor R14 is connected with one end of a seventh capacitor C7 and a connection terminal thereof is an output terminal of the, the other end of the sixth resistor R6, the other end of the tenth resistor R10 and the other end of the seventh capacitor C7 are all connected to ground.
Further, in terms of the resistance value, R3 ═ R4, R5 ═ R7, R6 ═ R8, and R9 ═ R11 ═ 2 ═ R10 ═ 2 ═ R12, then the voltage signal output by the signal conditioning module 4 is Vadc＝R8/R7*R12/R11*R4*Is+0.5*VccWherein, R3 represents the resistance value of the third resistor R3, R4 represents the resistance value of the fourth resistor R4, R5 represents the resistance value of the fifth resistor R5, R6 represents the resistance value of the sixth resistor R6, R7 represents the resistance value of the seventh resistor R7, R8 represents the resistance value of the eighth resistor R8, R9 represents the resistance value of the ninth resistor R9, R10 represents the resistance value of the tenth resistor R10, R11 represents the resistance value of the eleventh resistor R11, R12 represents the resistance value of the twelfth resistor R12, VccRepresents the positive voltage output by the positive voltage output of the charge control and energy storage module 3, IsRepresenting the current output by the first output terminal of the single winding current transformer 1.
The self-powered wireless current monitoring system based on the single-winding current transformer in the embodiment specifically works as follows: input to the filter rectification and current sampling module 2Current IsFirstly, two groups of LC filters consisting of a first inductor L1, a first capacitor C1, a second inductor L2 and a second capacitor C2 are used for low-pass filtering to improve the signal-to-noise ratio; then, a full-bridge rectifier circuit composed of the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 rectifies the dc voltage VrThe voltage is output to the charging control and energy storage module 3, and on the other hand, a third resistor R3 and a fourth resistor R4 which are connected in series in two bridge arms of the full-bridge rectification circuit respectively sample the positive half cycle and the negative half cycle of the input alternating current to obtain two paths of analog voltage signals V+And V－Outputting the signal to a signal conditioning module 4; microcontroller 5 monitors the lithium cell BAT electric quantity of charge control and energy storage module 3, and when the lithium cell BAT electric quantity is not enough, microcontroller 5 controls VshtIs high level and VenAt a high level, a DC voltage VrThe voltage is input to a DC-DC direct current converter U1 for voltage conversion and charging of a lithium battery BAT; when the lithium battery BAT is saturated, the microcontroller 5 controls VshtIs low level sum VenWhen the voltage is at a low level, the direct current voltage Vr is pulled down to the reference ground, meanwhile, the DC-DC converter U1 stops working, and the lithium battery BAT stops charging; in the signal conditioning module 4, the first operational amplifier OP1 samples the two input current signals V+And V－Differential amplification is carried out to generate a path of bipolar analog voltage signal, then the second operational amplifier OP2 carries out direct current bias on the bipolar analog voltage signal to generate a path of unipolar analog voltage signal, and finally the third operational amplifier OP3 carries out voltage following on the unipolar analog voltage signal to output a path of low-impedance unipolar analog voltage signal VadcTo the microcontroller 5, the microcontroller 5 inputs an analog voltage signal V to the inputadcAnd performing analog-to-digital conversion to obtain a digital signal, processing the digital signal, and transmitting the processed digital signal to the wireless transmitting module 6 for wireless transmission.
Claims (4)
1. A self-powered wireless current monitoring system based on a single-winding current transformer comprises an acquisition element and a monitoring circuit, and is characterized in that the acquisition element is realized by adopting a conventional single-winding current transformer, and the monitoring circuit comprises a filtering rectification and current sampling module, a charging control and energy storage module, a signal conditioning module, a microcontroller and a wireless transmitting module; the single-winding current transformer is used for inducing alternating current in a cable to be detected and then generating alternating current in a secondary side coil of the cable to be detected and outputting the alternating current to the filtering rectification and current sampling module, the filtering rectification and current sampling module firstly filters the alternating current input into the filtering rectification and current sampling module and then rectifies the alternating current to generate direct current voltage and outputs the direct current voltage to the charging control and energy storage module, the other side of the filtering rectification and current sampling module respectively samples a positive half cycle and a negative half cycle of the alternating current input into the filtering rectification and current sampling module to obtain two sampling signals, the two sampling signals are converted into two paths of analog voltage signals and output the two paths of analog voltage signals to the signal conditioning module, the charging control and energy storage module supplies power to the signal conditioning module, the microcontroller and the wireless transmitting module, and the signal conditioning module sequentially differentially amplifies the two paths of analog voltage signals input into the signal conditioning, After direct current bias and impedance conversion, generating a path of analog voltage signal and outputting the analog voltage signal to the microcontroller, wherein the microcontroller monitors the voltage of the charging control and energy storage module on one hand, controls the charging control and energy storage module to charge when the charging control and energy storage module is not saturated, and on the other hand, performs analog-to-digital conversion on the analog voltage signal input into the microcontroller to obtain a digital signal, and then transmits the digital signal to the wireless transmitting module for wireless transmission after processing;
the filter rectification and current sampling module is provided with a first input end, a second input end, a positive sampling output end, a negative sampling output end and a direct current voltage output end, the charging control and energy storage module is provided with an input end, a first control end, a second control end, a positive voltage output end and a negative voltage output end, the microcontroller is provided with an input end, a first control end, a second control end and an output end, the signal conditioning module is provided with a positive input end, a negative input end and an output end, the first input end of the filter rectification and current sampling module is connected with one end of a secondary side coil of the single-winding current transformer, the second input end of the filter rectification and current sampling module is connected with the other end of the secondary side coil of the single-winding current transformer, the direct current voltage output end of the filter rectification and current sampling module is connected with the input end of the charging control and energy storage module, the positive sampling output end of the filtering rectification and current sampling module is connected with the positive input end of the signal conditioning module, the negative sampling output end of the filtering rectification and current sampling module is connected with the negative input end of the signal conditioning module, the output end of the signal conditioning module is connected with the input end of the microcontroller, the output end of the microcontroller is connected with the wireless transmitting module, the first control end of the microcontroller is connected with the first control end of the charging control and energy storage module, the second control end of the microcontroller is connected with the second control end of the charging control and energy storage module, the positive voltage output end and the negative voltage output end of the charging control and energy storage module output positive and negative power voltages to supply power for the signal conditioning module, the microcontroller and the wireless transmitting module, when the charging control and energy storage module is in a default state, the voltage of the first control end of the charging control and energy storage module is pulled down to a reference ground by the microcontroller, the voltage of the second control end of the charging control and energy storage module is pulled up to a high level by the microcontroller, the charging control and energy storage module performs voltage conversion on the direct current voltage connected to the input end of the charging control and energy storage module and then performs charging, the microcontroller performs real-time voltage monitoring on the charging control and energy storage module, when the charging control and energy storage module is detected to be saturated, the first control end of the microcontroller outputs a high level, so that the voltage of the first control end of the charging control and energy storage module is a high level, the second control end of the microcontroller outputs a low level, so that the voltage of the second control end of the charging control and energy storage module is a low level, and at the moment, the charging control and energy storage module stops charging.
2. The system of claim 1, wherein the filter rectification and current sampling module comprises a first capacitor, a second capacitor, a first inductor, a second inductor, a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode, a second diode, a third diode, and a fourth diode; one end of the first capacitor, one end of the first inductor and one end of the first resistor are connected, the connection end of the first capacitor is the first input end of the filter rectification and current sampling module, one end of the second capacitor, one end of the second inductor and one end of the second resistor are connected, the connection end of the second capacitor is the second input end of the filter rectification and current sampling module, the other end of the first inductor, the other end of the first resistor, the anode of the first diode and the cathode of the third diode are connected, the other end of the second inductor, the other end of the second resistor, the anode of the second diode and the cathode of the fourth diode are connected, the cathode of the first diode is connected with the cathode of the second diode, and the connection end of the first diode is the dc voltage output end of the filter rectification and current sampling module, the positive pole of third diode with the one end of third resistance connect and its link does the positive sampling output of filtering rectification and current sampling module, the positive pole of fourth diode with the one end of fourth resistance connect and its link does the negative sampling output of filtering rectification and current sampling module, the other end of first electric capacity the other end of second electric capacity the other end of third resistance with the other end of fourth resistance connect and its link does the earthing terminal of filtering rectification and current sampling module, the earthing terminal of filtering rectification and current sampling module with consult ground and be connected.
3. The self-powered wireless current monitoring system based on the single-winding current transformer of claim 1, wherein the charging control and energy storage module comprises a first NMOS transistor, a third inductor, a fifth diode, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a first voltage regulator tube, a DC-DC converter, a lithium battery, a positive voltage linear regulator and a negative voltage linear regulator; the DC-DC direct current converter is provided with an input end, an output end, a control end and a grounding end, the drain electrode of the first NMOS tube is connected with the anode of the fifth diode, the connecting end of the first NMOS tube is the input end of the charging control and energy storage module, the cathode of the fifth diode, one end of the third capacitor and the cathode of the first voltage stabilizing tube are connected with the input end of the DC-DC direct current converter, the output end of the DC-DC direct current converter, the anode of the lithium battery are connected with one end of the third inductor, the other end of the third inductor, one end of the fourth capacitor, the input end of the positive voltage linear voltage stabilizer are connected with the input end of the negative voltage linear voltage stabilizer, the output end of the positive voltage linear voltage stabilizer is connected with one end of the fifth capacitor, and the connecting end of the positive voltage linear voltage stabilizer is the positive voltage output end of the charging control and energy storage module, the output end of the negative voltage linear voltage stabilizer is connected with one end of the sixth capacitor, the connecting end of the negative voltage linear voltage stabilizer is the negative voltage output end of the charging control and energy storage module, the source electrode of the first NMOS tube, the other end of the third capacitor, the anode of the first voltage stabilizer tube, the grounding end of the DC-DC direct current converter, the cathode of the lithium battery, the other end of the fourth capacitor, the grounding end of the positive voltage linear voltage stabilizer, the grounding end of the negative voltage linear voltage stabilizer, the other end of the fifth capacitor and the other end of the sixth capacitor are connected, the connecting end of the fifth capacitor and the grounding end of the sixth capacitor are the grounding end of the charging control and energy storage module, the grounding end of the charging control and energy storage module is connected with a reference ground, the grid electrode of the first NMOS tube is the first control end of the charging control and energy storage module, and the control end of the DC-DC direct current converter is a second control end of the charging control and energy storage module.
4. The self-powered wireless current monitoring system based on the single-winding current transformer of claim 1, wherein the signal conditioning module comprises a first operational amplifier, a second operational amplifier, a third operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a seventh capacitor; the first operational amplifier, the second operational amplifier and the third operational amplifier are respectively provided with a positive input end, a negative input end, an output end, a positive power supply end and a negative power supply end, one end of a fifth resistor is the positive input end of the signal conditioning module, the other end of the fifth resistor, the positive input end of the first operational amplifier and one end of a sixth resistor are connected, one end of a seventh resistor is the negative input end of the signal conditioning module, the other end of the seventh resistor, the negative input end of the first operational amplifier and one end of an eighth resistor are connected, the other end of the eighth resistor, the output end of the first operational amplifier and one end of an eleventh resistor are connected, the other end of the eleventh resistor, the negative input end of the second operational amplifier and one end of a twelfth resistor are connected, the other end of the twelfth resistor, the output end of the second operational amplifier and the positive input end of the third operational amplifier are connected, one end of the ninth resistor, the positive power end of the first operational amplifier, the positive power end of the second operational amplifier and the positive power end of the third operational amplifier are connected, and the connection end of the ninth resistor is connected with the positive voltage output end of the charge control and energy storage module, the negative power end of the first operational amplifier, the negative power end of the second operational amplifier and the negative power end of the third operational amplifier are connected, and the connection end of the first operational amplifier, the negative power end of the second operational amplifier and the negative power end of the third operational amplifier is connected with the negative voltage output end of the charge control and energy storage module, the other end of the ninth resistor, the positive input end of the second operational amplifier and one end of the tenth resistor are connected, one end of the thirteenth resistor is connected with the negative input end of the third operational amplifier, the other end of the thirteenth resistor, the output end of the third operational amplifier and one end of the fourteenth resistor are connected, the other end of the fourteenth resistor is connected with one end of the seventh capacitor, the connection end of the fourteenth resistor is the output end of the signal conditioning module, and the other end of the sixth resistor, the other end of the tenth resistor and the other end of the seventh capacitor are all connected with a reference ground.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910433058.8A CN110208597B (en) | 2019-05-23 | 2019-05-23 | Self-powered wireless current monitoring system based on single-winding current transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910433058.8A CN110208597B (en) | 2019-05-23 | 2019-05-23 | Self-powered wireless current monitoring system based on single-winding current transformer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110208597A CN110208597A (en) | 2019-09-06 |
| CN110208597B true CN110208597B (en) | 2021-04-23 |
Family
ID=67788230
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910433058.8A Active CN110208597B (en) | 2019-05-23 | 2019-05-23 | Self-powered wireless current monitoring system based on single-winding current transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110208597B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111585358B (en) * | 2020-07-02 | 2022-05-03 | 国网山东省电力公司电力科学研究院 | Multi-type single-winding coil power supply measurement integrated device special for microcomputer protection |
| CN111912436A (en) * | 2020-08-05 | 2020-11-10 | 广州彩熠灯光股份有限公司 | Self-powered rotation sensing device |
| CN111736006B (en) * | 2020-08-07 | 2020-11-24 | 成都市易冲半导体有限公司 | Convenient detection method applied to wireless charging coil RMS current |
| CN114167127A (en) * | 2021-11-24 | 2022-03-11 | 镇江市丹高电器有限公司 | Self-powered current transformer |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202948054U (en) * | 2012-12-20 | 2013-05-22 | 江苏通驰自动化系统有限公司 | Haff structure type high voltage wireless data acquisition device |
| CN204012952U (en) * | 2014-07-04 | 2014-12-10 | 江苏国网自控科技股份有限公司 | A kind of novel self-powered wireless temperature measurement transducer is got can circuit |
| CN104635032A (en) * | 2015-02-26 | 2015-05-20 | 北华大学 | Three-phase current wireless detection device |
| CN205566096U (en) * | 2016-02-23 | 2016-09-07 | 西安唯电电气技术有限公司 | High voltage direct current wide region input power auxiliary power supply circuit |
| CN106707008A (en) * | 2016-12-27 | 2017-05-24 | 成都信息工程大学 | Electronic current transformer and working method thereof |
| KR20170131911A (en) * | 2016-05-23 | 2017-12-01 | 전자부품연구원 | Current Metering Apparatus and Method using an Energy Harvesting based on Current Sensor |
| CN108710017A (en) * | 2018-05-03 | 2018-10-26 | 南京蓝园精瑞电气有限公司 | It is a kind of that electricity and measurement switching apparatus and system are taken based on single magnetic loop |
| CN208060610U (en) * | 2018-05-03 | 2018-11-06 | 南京蓝园精瑞电气有限公司 | It is a kind of that electricity and measurement switching apparatus and system are taken based on single magnetic loop |
| CN208689107U (en) * | 2018-08-31 | 2019-04-02 | 威胜电气有限公司 | Novel unicoil power supply sample circuit and its manufactured low-voltage circuit breaker |
-
2019
- 2019-05-23 CN CN201910433058.8A patent/CN110208597B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202948054U (en) * | 2012-12-20 | 2013-05-22 | 江苏通驰自动化系统有限公司 | Haff structure type high voltage wireless data acquisition device |
| CN204012952U (en) * | 2014-07-04 | 2014-12-10 | 江苏国网自控科技股份有限公司 | A kind of novel self-powered wireless temperature measurement transducer is got can circuit |
| CN104635032A (en) * | 2015-02-26 | 2015-05-20 | 北华大学 | Three-phase current wireless detection device |
| CN205566096U (en) * | 2016-02-23 | 2016-09-07 | 西安唯电电气技术有限公司 | High voltage direct current wide region input power auxiliary power supply circuit |
| KR20170131911A (en) * | 2016-05-23 | 2017-12-01 | 전자부품연구원 | Current Metering Apparatus and Method using an Energy Harvesting based on Current Sensor |
| CN106707008A (en) * | 2016-12-27 | 2017-05-24 | 成都信息工程大学 | Electronic current transformer and working method thereof |
| CN108710017A (en) * | 2018-05-03 | 2018-10-26 | 南京蓝园精瑞电气有限公司 | It is a kind of that electricity and measurement switching apparatus and system are taken based on single magnetic loop |
| CN208060610U (en) * | 2018-05-03 | 2018-11-06 | 南京蓝园精瑞电气有限公司 | It is a kind of that electricity and measurement switching apparatus and system are taken based on single magnetic loop |
| CN208689107U (en) * | 2018-08-31 | 2019-04-02 | 威胜电气有限公司 | Novel unicoil power supply sample circuit and its manufactured low-voltage circuit breaker |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110208597A (en) | 2019-09-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110208597B (en) | Self-powered wireless current monitoring system based on single-winding current transformer | |
| CN104201892B (en) | A kind of input voltage measurement method of isolation inverse-excitation type high frequency switch power and circuit | |
| CN113533817B (en) | Electronic voltage transformer and electric energy metering equipment thereof | |
| CN205123588U (en) | It turns over to keep apart swashs formula high frequency switching power supply and input voltage detection circuitry thereof | |
| KR101268942B1 (en) | Measuring circuit for internal resistance of battery or cell | |
| CN109270337A (en) | Passive and wireless current sensor based on double-winding current mutual inductor | |
| CN207516439U (en) | Alternating current acquisition module and detection device | |
| CN104502673A (en) | AC-DC general current true RMS transmitter | |
| CN115097182A (en) | Dual-output measurement's alternating current-direct current sensor's adapter device | |
| CN211061633U (en) | Direct current insulation monitoring device based on alternating current and direct current leakage current sensor | |
| CN209881480U (en) | Adapter control circuit and adapter | |
| CN104407208B (en) | A kind of system of utilization circuit energy based on the relatively quasi- current in resistance property measurement of the positive inverse transformations of Fourier FFT | |
| CN204131397U (en) | A kind of input voltage detection circuit of isolating inverse-excitation type high frequency switch power | |
| CN217981614U (en) | Multifunctional adapting device of alternating current and direct current sensor | |
| CN101615501B (en) | Voltage and current integral sampling device | |
| CN216979169U (en) | Grounding current monitoring device and system | |
| CN212646803U (en) | Real-time power consumption detection system | |
| CN216747855U (en) | High-voltage alternating current-direct current voltage collection system of effective isolation | |
| CN204241544U (en) | The current true virtual value transmitter of AC/DC universal | |
| CN108631619B (en) | Adapter control circuit and adapter | |
| CN112611912B (en) | Circuit sampling system | |
| CN205564013U (en) | Circuit system suitable for differential capacitive sensor signal of long distance transmission | |
| CN216082970U (en) | Mutual inductor interface circuit and circuit breaker | |
| CN219496523U (en) | Power supply connection circuit of electric energy metering system | |
| CN103227451A (en) | Undervoltage and overvoltage detection and protection method of network voltage, and detection and protection device of method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |