CN217766596U - Wide-range alternating voltage measuring circuit - Google Patents
Wide-range alternating voltage measuring circuit Download PDFInfo
- Publication number
- CN217766596U CN217766596U CN202221096160.7U CN202221096160U CN217766596U CN 217766596 U CN217766596 U CN 217766596U CN 202221096160 U CN202221096160 U CN 202221096160U CN 217766596 U CN217766596 U CN 217766596U
- Authority
- CN
- China
- Prior art keywords
- voltage
- circuit
- current
- voltage transformer
- measurement
- 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
Images
Landscapes
- Measurement Of Current Or Voltage (AREA)
Abstract
The utility model provides a wide range alternating voltage measuring circuit, switch current-limiting resistance circuit, high accuracy measurement voltage transformer and measuring circuit including alternating voltage input, current-limiting resistance, isolation detection voltage transformer, rectification filter circuit, amplitude comparison circuit, CPU detection circuitry, drive relay. The isolation detection voltage transformer and the high-precision measurement voltage transformer are connected in parallel to be connected with an alternating current voltage to be measured, a current-limiting resistor is arranged on the primary side, the alternating current signal is subjected to AD/DC conversion through the isolation detection voltage transformer and the rectification filter circuit after being input, the relay driving circuit is controlled to switch the primary current-limiting resistor of the high-precision voltage transformer after the signal is output through the amplitude comparison circuit, the wide-range measurement of the alternating current voltage is completed, meanwhile, the amplitude comparison output signal is connected into the CPU for detection, and input range information used by the measurement signal is obtained.
Description
Technical Field
The utility model belongs to the technical field of the electron measurement, concretely relates to wide range alternating voltage measuring circuit.
Background
At present, the alternating voltage measurement range generally carried out on secondary or low-voltage sites in a power grid is 20V to 500V, in order to ensure the use safety of instruments and operators, voltage isolation is reduced to the measurement range of a measurement instrument by using a voltage transformer, and the amplitude, the phase and other information of voltage are obtained by sampling and measuring on a secondary side instead of simple resistance voltage division measurement. When the high voltage PT is 10kv to 500kv primary voltage, the secondary voltage or the low voltage is usually phase voltage 57V or 220V (line voltage 100V or 380V), and the range of the measuring instrument is also usually applied to this range. When the maintenance or test is carried out in a power failure state, when the primary voltage supplies power for 220V by using the alternating-current voltage of the standby test power supply, the secondary voltage is very small and only millivolt level, the amplitude phase of the small voltage is difficult to measure, and the phase checking and transformation ratio test cannot be carried out. Therefore, in the power system, how to develop the alternating voltage measurement towards a wider measurement range is to adapt to the increasingly complex power grid environment, meet the field requirements of the power industry, and play a powerful role in promoting the protection of the transformer substation and the protection of the measurement system on the alternating voltage measurement.
Disclosure of Invention
The utility model discloses an alternating voltage measurement range that the purpose is superior to at present commonly used provides one kind and can satisfy wide range alternating voltage amplitude phase measurement's circuit, solves the alternating current instrument that has voltage transformer and at the measuring problem of voltage at the small-signal.
Realize the utility model discloses the technical solution of purpose: a wide range alternating voltage measuring circuit, switch current-limiting resistance circuit, high accuracy measurement voltage transformer and measuring circuit including alternating voltage input, current-limiting resistance, isolation detection voltage transformer, rectification filter circuit, amplitude comparison circuit, CPU detection circuitry, drive relay. The isolation detection voltage transformer and the high-precision measurement voltage transformer are connected in parallel to be connected with the measured alternating current voltage, and a current-limiting resistor is arranged on the primary side of the isolation detection voltage transformer; the drive relay switching current-limiting resistance circuit comprises a triode drive circuit and a relay.
The utility model discloses parallelly connected isolation detection voltage transformer and high accuracy measurement mutual-inductor keep apart and are surveyed alternating voltage and secondary measuring circuit, the secondary voltage signal after alternating signal input keeps apart detection voltage transformer carries out AD/DC conversion through rectification filter circuit, be connected to amplitude comparison circuit, convert the secondary voltage into direct current after and compare with reference voltage, amplitude comparison circuit output signal drives opening and shutting of relay, the relay control signal is kept apart with primary voltage signal, the change of relay control high accuracy measurement voltage transformer primary current limiting resistance carries out the small signal measurement of alternating signal under keeping apart the input; meanwhile, the output of the amplitude comparison circuit is connected to a CPU detection circuit for detection, and software processing is carried out to obtain the input range information used by the measurement signal.
The utility model discloses amplitude comparison circuit output high level, high accuracy measurement voltage transformer uses two current-limiting resistor series connections to measure, measures voltage transformer primary and secondary current in normal range, measures safely when guaranteeing the big voltage, high accuracy measurement when carrying out the big voltage, CPU detection circuitry detects the high level simultaneously, uses normal voltage range to calculate ADC measuring result;
the utility model discloses amplitude comparison circuit output low level, high accuracy measurement voltage transformer is once current-limiting resistance by the short circuit, and total current-limiting resistance reduces, measures a voltage transformer secondary current increase, sends into the ADC through the same sampling circuit's of secondary side sampling signal grow, also can carry out the high accuracy measurement when carrying out the small-voltage, and CPU detection circuitry detects the low level simultaneously, uses the small-voltage range to calculate and shows measuring result.
As the utility model discloses a what preferred technical scheme reached is showing the effect: (1) The utility model has the advantages that the input of the measured alternating voltage is isolated from the internal measurement control circuit, and the measurement is safe and reliable; (2) The utility model outputs the driving relay to automatically switch and measure the primary current-limiting resistance circuit of the voltage transformer by comparing the secondary voltage of the voltage transformer with the reference voltage after rectification and filtration, the switching action is fast, and the safety is high; (3) The utility model discloses a select to measure voltage transformer input end current limiting resistor resistance value and can realize wide range alternating voltage amplitude, phase test.
Drawings
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
FIG. 1 is a schematic diagram of the measuring circuit of the present invention;
fig. 2 is a schematic diagram of the simple circuit of the present invention.
Detailed Description
In the description of the present invention, it should be noted that the terms "vertical", "upper", "lower", "horizontal", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The utility model provides a wide range alternating voltage measuring circuit, refer to fig. 1 and explain the whole system of circuit module, include alternating voltage input 1, current-limiting resistor 2, keep apart detection voltage transformer 3, rectification filter circuit 4, amplitude comparison circuit 5, drive relay switching current-limiting resistor circuit 6, high accuracy measurement voltage transformer 7, measuring circuit 8 and CPU9. The drive relay switching current-limiting resistance circuit 6 comprises a triode drive circuit 6-1 and a relay 6-2, an alternating current voltage input end 1 is connected with a current-limiting resistor 2, the current-limiting resistor R1 and the current-limiting resistor R2 of the current-limiting resistor 2 are located on the primary side of an isolation detection voltage transformer 3, the current-limiting resistor R3 and the current-limiting resistor R4 of the current-limiting resistor 2 are located on the primary side of a high-precision measurement voltage transformer 7, the secondary side output of the isolation detection voltage transformer 3 is connected with a rectification filter circuit 4, the rectification filter circuit 4 is connected with an amplitude comparison circuit 5, the amplitude comparison circuit 5 is connected with the triode drive circuit 6-1 of the drive relay switching current-limiting resistor circuit 6, the triode drive circuit 6-1 is connected with the relay 6-2, the relay 6-2 is connected with the current-limiting resistor R3 in the current-limiting resistor 2, the current-limiting resistor R3 and the current-limiting resistor R4 in the current-limiting resistor 2 are connected with the high-precision measurement voltage transformer 7, the high-precision measurement voltage transformer 7 is connected with a measurement circuit 8, and the measurement circuit 8 is connected with an ADC.
The utility model discloses an keep apart and detect voltage transformer 3 and high accuracy measurement volume measurement voltage transformer 7 parallel connection and insert by the alternating voltage of surveying, once incline all to have current limiting resistor 2. After an alternating current signal is input, AD/DC conversion is carried out through an isolation detection voltage transformer 3 and a rectification filter circuit 4, a signal is output through an amplitude comparison circuit 5, a relay driving circuit is controlled to switch a primary current limiting resistor of a high-precision voltage transformer, small-signal measurement of the alternating current voltage is finally achieved through a high-precision measurement voltage transformer 7 and a measurement circuit 8, meanwhile, an amplitude comparison result is sent to a CPU9 for detection and used for software processing, and input range information used by the measurement signal is obtained.
The utility model discloses an input characteristic, alternating voltage input will measure and control scheme keeps apart through 3 isolation detection voltage transformer and high accuracy measurement voltage transformer 7, and alternating voltage and secondary measuring circuit keep apart, and relay 6-2 keeps apart control signal and primary voltage signal, utilizes the change of the quick automatic switch-over control current-limiting resistance R3 of relay 6-2, realizes wide range voltage measurement, and the security is high.
Specifically, a preferred embodiment of the present invention will be described with reference to fig. 2.
The interfaces of the AC voltage input end of the utility model are AC-IN + and AC-IN-; r1 and R2 are primary side current limiting resistors of the T1 isolation detection voltage transformer, R3 and R4 are primary side current limiting resistors of the T2 high-precision measurement voltage transformer, resistance values meet the relation that R3=99R4, and wide-range measurement of 5mV-500V of alternating voltage can be achieved.
The utility model D1, D2, D3 and D4 form a bridge rectifier circuit, the positive electrode of an alternating current signal passes through the T1 isolation detection voltage transformer and is connected between D1 and D2, the negative electrode is connected between D4 and D3, the space between D2 and D3 is used as the positive electrode output end to be connected with a next-stage circuit, and the space between D1 and D4 is used as the negative electrode output end to be connected with a next-stage circuit; converting an input alternating voltage into a pulsating direct current voltage signal with unchanged direction by using the single-phase conductivity of a diode, conducting D2 and D4 in a positive half period of the alternating voltage input, stopping D1 and D3, conducting D1 and D3 in a negative half period of the alternating voltage input, and stopping D2 and D4; the input AC voltage is effective value, and the output DC voltage signal is average value.
The utility model discloses L1, C1 and C2 constitute LC-pi type filter circuit, utilize the nature that energy storage component capacitor C1, C2 and inductor L1's alternating current impedance is little, the direct current open circuit, the voltage on both sides can not be sudden change, with the further filtering of alternating current signal among the pulsating direct current voltage, make output voltage's pulsation littleer, output signal is more level and smooth.
The utility model is characterized in that the R5, R6, R7 and U1 form an amplitude voltage comparison circuit, the measured voltage after the rectification filtering is compared with the reference voltage, the measured voltage is input to the negative end of the amplifier, and the R5 and R6 divider resistors obtain the reference voltage; when the voltage input is in a small voltage range, the measured voltage after rectification and filtering is smaller than the reference voltage, the comparison circuit outputs a high level, the high level is input into the triode drive circuit, and meanwhile, the CPU detects the high level; after rectification, the detected voltage is greater than the reference voltage, the comparison circuit outputs a low level and inputs the low level to the triode drive circuit, and meanwhile, the CPU detects the low level.
The utility model discloses R8, R9 and Q1 constitute triode drive circuit, can adopt NPN type triode, and when input triode drive circuit is the high level, the triode switches on, when input triode drive circuit is the low level, the triode ends; the pull-down resistor R9 effectively prevents the error action of the relay caused by the error touch of the triode Q1.
Utility model relay K1 is closed when the triode switches on, breaks off when the triode ends. The K1 relay node is connected with a current limiting resistor R3, the state of the primary side of the T2 high-precision measurement voltage transformer is controlled to be accessed through the action of the relay, when the relay is closed, the R3 is in short circuit, the resistance value of the T2 primary side total current limiting resistor is reduced, and the primary current and the secondary current are increased; when the relay is opened, the T2 high-precision measurement voltage transformer uses two current-limiting resistors R3 and R4 to carry out series measurement, and the primary current and the secondary current are in a normal measurement range.
The utility model discloses R10, D6, D7, PR1, U3, C3, R11 constitute measuring circuit, take a sample to the voltage input signal of T1 high accuracy measurement voltage transformer secondary side, and the secondary current is in normal measuring range, guarantees safety when big voltage measurement, realizes the high accuracy measurement when big voltage, and CPU detects the low level simultaneously, uses normal voltage range to calculate ADC measuring result; after the secondary current is increased, a sampling signal of the sampling circuit is increased and is sent to the ADC for measurement software processing, high-precision measurement can be performed even when small voltage is achieved, and meanwhile, the CPU detects high level and can calculate and display a measurement result by using a small voltage range.
Finally, it should be noted that: the above description is only for the purpose of illustrating the embodiments of the present invention and is not intended to limit the present invention, and it will be apparent to those skilled in the art that the present invention may be modified in the technical solutions described in the foregoing embodiments or may be substituted for some of the technical features. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (4)
1. A wide-range alternating voltage measuring circuit is characterized by comprising an alternating voltage input end, a current-limiting resistor, an isolation detection voltage transformer, a rectification filter circuit, an amplitude comparison circuit, a CPU detection circuit, a driving relay switching current-limiting resistor circuit, a high-precision measurement voltage transformer and a measuring circuit;
the isolation detection voltage transformer and the high-precision measurement voltage transformer are connected in parallel to be connected with the measured alternating current voltage, and a current-limiting resistor is arranged on the primary side of the isolation detection voltage transformer;
the drive relay switching current-limiting resistance circuit comprises a triode drive circuit and a relay;
the alternating voltage input end is connected with a primary side current limiting resistor, and each primary side current limiting resistor is correspondingly connected with an isolation detection voltage transformer and a high-precision measurement voltage transformer; the secondary voltage of the isolation detection voltage transformer enters an amplitude voltage comparison circuit after passing through a rectification filter circuit, and is converted into direct current and then compared with reference voltage; the amplitude comparison circuit is connected with a switching current-limiting resistance circuit of the driving relay, and an output signal of the amplitude comparison circuit drives the switching of the relay through the triode driving circuit; the drive relay switching current-limiting resistance circuit is connected to a current-limiting resistance at the primary side of the high-precision measurement voltage transformer, a relay control signal is isolated from a primary voltage signal, and the relay is used for controlling the change of the primary current-limiting resistance of the high-precision measurement voltage transformer; the high-precision measurement voltage transformer is connected with the measurement circuit, so that the small signal measurement problem of the alternating current signal under isolated input is realized; meanwhile, the amplitude comparison circuit is connected with the CPU detection circuit, and the output of the amplitude comparison circuit is sent to the CPU for detection so as to obtain the range information used by the measurement signal.
2. The wide-range alternating voltage measuring circuit according to claim 1, wherein a secondary voltage of the alternating voltage input isolation detection voltage transformer is rectified and filtered and then compared with a reference voltage, and a high-low level signal is output to drive the relay to automatically switch a primary current limiting resistor circuit of the measuring voltage transformer, so that the switching action is fast, the relay is fast in response, and the safety is high.
3. The wide-range alternating voltage measuring circuit according to claim 1, wherein the secondary voltage of the isolation detection voltage transformer is converted into direct current and then compared with the reference voltage, the amplitude comparison circuit outputs high level, the primary side current limiting resistor of the high-precision measurement voltage transformer is connected in series with the high-precision measurement voltage transformer, the primary current of the voltage transformer measured by the measuring circuit is within a normal range, the measurement safety at large voltage is ensured, and the high-precision measurement at large voltage is carried out; and meanwhile, the CPU detection circuit detects the output high level and calculates the ADC measurement result by using the normal voltage range.
4. The wide-range alternating voltage measuring circuit according to claim 1, wherein the secondary voltage of the isolation detection voltage transformer is converted into direct current and then compared with the reference voltage, the amplitude comparison circuit outputs low level, a current limiting resistor on the primary side of the high-precision measuring voltage transformer is short-circuited, the total current limiting resistor is reduced, the primary current of the measuring voltage transformer is increased, and a sampling signal is increased through a measuring circuit on the secondary side and sent to the ADC for high-precision measurement at low voltage; meanwhile, the CPU detection circuit detects the output low level and calculates and displays the measurement result by using a small voltage range.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221096160.7U CN217766596U (en) | 2022-05-09 | 2022-05-09 | Wide-range alternating voltage measuring circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221096160.7U CN217766596U (en) | 2022-05-09 | 2022-05-09 | Wide-range alternating voltage measuring circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217766596U true CN217766596U (en) | 2022-11-08 |
Family
ID=83884588
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221096160.7U Active CN217766596U (en) | 2022-05-09 | 2022-05-09 | Wide-range alternating voltage measuring circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217766596U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116593757A (en) * | 2023-07-17 | 2023-08-15 | 济南巧步思仪器仪表有限公司 | Alternating current ratio measuring method, system and digital alternating current comparator |
-
2022
- 2022-05-09 CN CN202221096160.7U patent/CN217766596U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116593757A (en) * | 2023-07-17 | 2023-08-15 | 济南巧步思仪器仪表有限公司 | Alternating current ratio measuring method, system and digital alternating current comparator |
| CN116593757B (en) * | 2023-07-17 | 2023-11-03 | 济南巧步思仪器仪表有限公司 | Alternating current ratio measuring method, system and digital alternating current comparator |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203365558U (en) | Circuit and device for three-phase power open-phase detection | |
| CN101325366A (en) | Circuit with protective circuit for correcting active power factor | |
| CN103196491B (en) | Transformer integral comprehensive detection device | |
| CN217766596U (en) | Wide-range alternating voltage measuring circuit | |
| CN103105572A (en) | Device for testing IGBT module | |
| CN106053954B (en) | Dc-link capacitance on-line monitoring method | |
| CN105245126A (en) | Teaching inverter system module | |
| CN209001595U (en) | Voltage dip controlling device | |
| CN115015744A (en) | AC charging pile relay adhesion detection circuit | |
| CN209044025U (en) | Closing self-checking device for bus coupler switch of dual-power direct-current system | |
| CN107478975A (en) | A kind of Insulation Inspection System of energy-accumulating power station | |
| CN203241490U (en) | Intelligent temperature rise testing system used for electrical products | |
| CN101902033A (en) | Intelligent protection device with zero pressure drop | |
| CN202939279U (en) | Test device of direct current circuit breaker | |
| CN204287447U (en) | A kind of alternating current-direct current input detecting circuit | |
| CN207977776U (en) | A kind of DC power cabinet | |
| CN205787992U (en) | Constant-current source control system | |
| CN115113095A (en) | Mutual inductor device with loop inspection function | |
| CN212845895U (en) | Voltage comparator module circuit in short-circuit fault warning device of ammeter | |
| CN204832485U (en) | A frequency conversion electron source for 750kV level CVT on -site proving system | |
| CN213275830U (en) | A insulating monitoring module for new forms of energy electric automobile direct current fills electric pile | |
| CN108237305A (en) | Electric welding machine power-down protection apparatus and electric welding machine | |
| CN209132334U (en) | A kind of vacuum circuit breaker divide-shut brake coil direct current resistance m easurem ent device | |
| CN203849399U (en) | Single-phase carrier wave intelligent electric energy meter mis-power failure fault analyzer | |
| CN204498067U (en) | The insulation tester of photovoltaic DC cabinet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |