CN207198238U - Mains frequency detects circuit - Google Patents
Mains frequency detects circuit Download PDFInfo
- Publication number
- CN207198238U CN207198238U CN201721132843.2U CN201721132843U CN207198238U CN 207198238 U CN207198238 U CN 207198238U CN 201721132843 U CN201721132843 U CN 201721132843U CN 207198238 U CN207198238 U CN 207198238U
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- circuit
- comparator
- input
- active filter
- power network
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Abstract
The utility model discloses a kind of mains frequency to detect circuit.Wherein, mains frequency detection circuit includes：Active filter circuit, input are connected with the output end of power network sample circuit, and the input of active filter circuit is used for the voltage sampling signal for receiving power network, and active filter circuit filters out interference noise for voltage sampling signal；Comparator circuit, the input of comparator circuit are connected with the output end of active filter circuit, and comparator circuit is used for the voltage sampling signal of active filter circuit output compared with reference voltage；Controller, controller are connected with the output end of comparator circuit, for the frequency of the signal of change power network exported according to comparator circuit.The utility model solves the relatively low technical problem of ratio of precision of detection mains frequency.
Description
Technical field
Circuit field is the utility model is related to, circuit is detected in particular to a kind of mains frequency.
Background technology
In existing photovoltaic system, because photovoltaic inverter system itself has serious interference, cause mains frequency
There is error in detection so that the waveform of photovoltaic DC-to-AC converter output is inaccurate, reduces the output performance of inverter, also reduces isolated island
The reliability of protection, in extreme circumstances, it is possible to cause the malfunction of inverter.
For it is above-mentioned the problem of, not yet propose effective solution at present.
The content of the invention
The utility model embodiment provides a kind of mains frequency detection circuit, at least to solve to detect the essence of mains frequency
Degree is than relatively low technical problem.
According to the one side of the utility model embodiment, there is provided a kind of mains frequency detects circuit, including：Active filter
Wave circuit, input are connected with the output end of power network sample circuit, and the input of the active filter circuit is used to receive institute
The voltage sampling signal of power network is stated, the active filter circuit filters out interference noise for the voltage sampling signal；Comparator
Circuit, the input of the comparator circuit are connected with the output end of the active filter circuit, and the comparator circuit is used
In the voltage sampling signal exported to the active filter circuit compared with reference voltage；Controller, the controller with
The output end of the comparator circuit is connected, the frequency for power network described in the signal of change that is exported according to the comparator circuit
Rate.
Alternatively, the mains frequency detection circuit also includes：Power network sample circuit, one end connect the power network, in addition
One end connects the active filter circuit, for being sampled to the voltage of the power network.
Alternatively, the power network sample circuit is the difference sample circuit of voltage sensor either high impedance composition.
Alternatively, the active filter circuit includes：Operational amplifier IC1；Resistance R1, first end sample with the power network
The output end of circuit is connected, and the second end is connected with operational amplifier IC1 first input end；Resistance R2, first end ground connection,
Second end is connected with the first input end of the operational amplifier IC1；Electric capacity C2, it is in parallel with the resistance R2；Resistance R4, the
One end is connected with the second input of the operational amplifier IC1, the second end and the output end phase of the operational amplifier IC1
Connection, wherein, the second input end grounding of the operational amplifier IC1；Electric capacity C1, it is in parallel with the resistance R4；Resistance R3, the
One end is connected with the output end of the operational amplifier IC1, output end of second end as the active filter circuit.
Alternatively, the value of the electric capacity C1 is different from the value of the electric capacity C2, and the value of the electric capacity C1 is more than described
Electric capacity C2 value.
Alternatively, 20 times of value of the value of the electric capacity C1 more than the electric capacity C2.
Alternatively, the comparator circuit includes：Comparator IC2；Resistance R5, first end and the active filter circuit
Output end is connected, and the second end is connected with the first input end of the comparator IC2；Electric capacity C3, one end and the comparator
IC2 first input end is connected, other end ground connection；Resistance R6, first end are connected with reference voltage, the second end with it is described
Comparator IC2 the second input is connected；Electric capacity C4, one end are connected with the second input of the comparator IC2, in addition
One end is grounded；Resistance R7, one end are connected with the output end of the comparator IC2, other end connection high level, wherein, institute
State output end of the comparator IC2 output end as the comparator circuit.
In the utility model embodiment, active filter circuit is connected with power network, can be to the voltage of the power network of collection
Sampled signal is filtered, and output signal is input in comparator circuit after filtering out interference noise, generates square-wave signal, square wave
Signal is easy for the signal of controller identification, and therefore, controller can accurately detect power network frequency according to the square-wave signal identified
Rate, has reached the technique effect for the accuracy of detection for improving detection mains frequency, and then solves the ratio of precision of detection mains frequency
Relatively low technical problem.
Brief description of the drawings
Accompanying drawing described herein is used for providing further understanding to of the present utility model, forms the part of the application,
Schematic description and description of the present utility model is used to explain the utility model, does not form to of the present utility model improper
Limit.In the accompanying drawings：
Fig. 1 is the schematic diagram that circuit is detected according to a kind of mains frequency of the utility model embodiment；
Fig. 2 is the circuit diagram according to the active filter circuit of the utility model embodiment；
Fig. 3 is the circuit diagram according to the comparator circuit of the utility model embodiment.
Embodiment
In order that those skilled in the art more fully understand the utility model, it is real below in conjunction with the utility model
The accompanying drawing in example is applied, the technical scheme in the embodiment of the utility model is clearly and completely described, it is clear that be described
Embodiment is only the embodiment of the utility model part, rather than whole embodiments.Based on the reality in the utility model
Example is applied, the every other embodiment that those of ordinary skill in the art are obtained under the premise of creative work is not made, all should
When the scope for belonging to the utility model protection.
The utility model embodiment provides a kind of mains frequency detection circuit.
Fig. 1 is the schematic diagram that circuit is detected according to the mains frequency of the utility model embodiment.As shown in figure 1, the power network
Frequency detection circuit includes：Active filter circuit 12, comparator circuit 14 and controller 16.Wherein：
Active filter circuit 12, input are connected with the output end of power network sample circuit, the input of active filter circuit
The voltage sampling signal for receiving power network is held, active filter circuit filters out interference noise for voltage sampling signal；
Comparator circuit 14, the input of comparator circuit are connected with the output end of active filter circuit, comparator electricity
Road is used for the voltage sampling signal of active filter circuit output compared with reference voltage；
Controller 16, controller are connected with the output end of comparator circuit, for the letter exported according to comparator circuit
Number calculate power network frequency.
The active filter circuit 12 is connected with power network, and the voltage sampling signal of the power network of collection can be filtered,
Output signal is input in comparator circuit 14 after filtering out interference noise, generates square-wave signal, square-wave signal is easy for controlling
The signal that device 16 identifies, therefore, controller can accurately detect mains frequency according to the square-wave signal identified, reach raising
The technique effect of the accuracy of detection of mains frequency is detected, solves the relatively low technology of the ratio of precision of prior art detection mains frequency
Problem.
The raising of the accuracy of detection of mains frequency is detected, helps to lift the grid-connected performance of inverter, improves isolated island protection
Reliability, reduce due to mains frequency accuracy of detection it is low caused by inverter by mistake protection generation.Also, what the circuit used
Electronic component is few, is easy to engineer applied.
Fig. 2 is the circuit diagram according to the active filter circuit of the utility model embodiment.As shown in Fig. 2 the active power filtering
Circuit includes：
Operational amplifier IC1；
Resistance R1, first end are connected with the output end of power network sample circuit, the second end and the first of operational amplifier IC1
Input is connected；
Resistance R2, first end ground connection, the second end is connected with operational amplifier IC1 first input end；
Electric capacity C2, it is in parallel with resistance R2；
Resistance R4, first end are connected with operational amplifier IC1 the second input, the second end and operational amplifier IC1
Output end be connected, wherein, operational amplifier IC1 the second input end grounding；
Electric capacity C1, it is in parallel with resistance R4；
Resistance R3, first end are connected with operational amplifier IC1 output end, and the second end is as the defeated of active filter circuit
Go out end.
Active filter circuit shown in Fig. 2 is made up of operational amplifier IC1 and its peripheral resistance, electric capacity.Line voltage
Sampled signal U1 is by being sent into operational amplifier IC1, output signal after filtered processing after resistance R1, resistance R2 and electric capacity C2
U2。
In order to improve the filtering performance of active filter, reduce delay of the filter circuit to signal sampling, in selection electric capacity
During C1 and electric capacity C2, the electric capacity C1 and electric capacity C2 of cause not of uniform size need to be chosen, and electric capacity C1 value is needed more than electric capacity C2's
20 times of value.
Fig. 3 is the circuit diagram according to the comparator circuit of the utility model embodiment.As shown in figure 3, the comparator circuit
Including：
Comparator IC2；
Resistance R5, first end are connected with the output end of active filter circuit, the second end and comparator IC2 the first input
End is connected；
Electric capacity C3, one end are connected with comparator IC2 first input end, other end ground connection；
Resistance R6, first end are connected with reference voltage, and the second end is connected with comparator IC2 the second input；
Electric capacity C4, one end are connected with comparator IC2 the second input, other end ground connection；
Resistance R7, one end are connected with comparator IC2 output end, other end connection high level, wherein, comparator
Output end of the IC2 output end as comparator circuit.
Comparator circuit shown in Fig. 3 is made up of comparator IC2 and peripheral resistance, electric capacity.By active shown in Fig. 2
The treated line voltage sampled signal U2 of filter circuit is input in comparator circuit by resistance R5 and electric capacity C3, makes power network
For voltage sampling signal U2 compared with reference voltage V_ref, generation is easy to the square-wave signal U3 that controller gathers, signal U3 to be controlled
Device gathers, and calculates the frequency of power network in real time.
Such as：Comparator IC2 is in relatively line voltage sampled signal U2 and reference voltage V_ref, if line voltage
Sampled signal U2 is more than reference voltage V_ref, then exports high level, if line voltage sampled signal U2 is less than or equal to ginseng
Voltage V_ref is examined, then exports low level.Thus, square-wave signal is generated.
It should be noted that the value of resistance and electric capacity in above-mentioned active filter circuit and comparator circuit, can basis
The needs of precision are selected and adjusted, and the present embodiment is not limited specific value.
Alternatively, mains frequency detection circuit also includes：Power network sample circuit, one end connection power network, other end connection
Active filter circuit, for being sampled to the voltage of power network.
Power network sample circuit is sampled to the voltage signal of power network, and sampled signal is directly output into active power filtering electricity
Road.Alternatively, power network sample circuit is the difference sample circuit of voltage sensor either high impedance composition.
, can be smart to just improving the sampling of mains frequency using active filter circuit and comparator circuit by the present embodiment
Degree, because the sampling precision of mains frequency influences the output performance of combining inverter, in certain extreme cases, mains frequency is adopted
The error of sample is likely to result in the mistake protection of inverter, and inverter is broken from network system, adds inverter wrong report event
The probability of barrier, the utilization rate of photovoltaic system is reduced, therefore, the general of inverter wrong report failure can be reduced by improving sampling precision
Rate.
Described above is only preferred embodiment of the present utility model, it is noted that for the common skill of the art
For art personnel, on the premise of the utility model principle is not departed from, some improvements and modifications can also be made, these improve and
Retouching also should be regarded as the scope of protection of the utility model.
Claims (7)
1. a kind of mains frequency detects circuit, it is characterised in that including：
Active filter circuit, input are connected with the output end of power network sample circuit, the input of the active filter circuit
For receiving the voltage sampling signal of power network, the active filter circuit filters out interference noise for the voltage sampling signal,
The power network sample circuit connects power network；
Comparator circuit, the input of the comparator circuit are connected with the output end of the active filter circuit, the ratio
It is used for compared with device circuit to the voltage sampling signal of active filter circuit output compared with reference voltage；
Controller, the controller are connected with the output end of the comparator circuit, for defeated according to the comparator circuit
The frequency of power network described in the signal of change gone out.
2. circuit according to claim 1, it is characterised in that the mains frequency detection circuit also includes：
The power network sample circuit, one end connect the power network, and other end connects the active filter circuit, for described
The voltage of power network is sampled.
3. circuit according to claim 2, it is characterised in that the power network sample circuit is that voltage sensor is either high
The difference sample circuit of impedance composition.
4. circuit according to claim 1, it is characterised in that the active filter circuit includes：
Operational amplifier IC1；
Resistance R1, first end are connected with the output end of the power network, the second end and operational amplifier IC1 first input end phase
Connection；
Resistance R2, first end ground connection, the second end is connected with the first input end of the operational amplifier I C1；
Electric capacity C2, it is in parallel with the resistance R2；
Resistance R4, first end are connected with the second input of the operational amplifier IC1, the second end and the operational amplifier
IC1 output end is connected, wherein, the second input end grounding of the operational amplifier IC1；
Electric capacity C1, it is in parallel with the resistance R4；
Resistance R3, first end are connected with the output end of the operational amplifier IC1, and the second end is as the active filter circuit
Output end.
5. circuit according to claim 4, it is characterised in that the value of the electric capacity C1 is different from the value of the electric capacity C2,
And the value of the electric capacity C1 is more than the value of the electric capacity C2.
6. circuit according to claim 5, it is characterised in that the 20 of value of the value of the electric capacity C1 more than the electric capacity C2
Times.
7. circuit according to claim 1, it is characterised in that the comparator circuit includes：
Comparator IC2；
Resistance R5, first end are connected with the output end of the active filter circuit, the second end and the first of the comparator IC2
Input is connected；
Electric capacity C3, one end are connected with the first input end of the comparator IC2, other end ground connection；
Resistance R6, first end are connected with reference voltage, and the second end is connected with the second input of the comparator IC2；
Electric capacity C4, one end are connected with the second input of the comparator IC2, other end ground connection；
Resistance R7, one end are connected with the output end of the comparator IC2, other end connection high level, wherein, the comparison
Output end of the device IC2 output end as the comparator circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721132843.2U CN207198238U (en) | 2017-09-04 | 2017-09-04 | Mains frequency detects circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721132843.2U CN207198238U (en) | 2017-09-04 | 2017-09-04 | Mains frequency detects circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207198238U true CN207198238U (en) | 2018-04-06 |
Family
ID=61791171
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721132843.2U Active CN207198238U (en) | 2017-09-04 | 2017-09-04 | Mains frequency detects circuit |
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| CN (1) | CN207198238U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107589298A (en) * | 2017-09-04 | 2018-01-16 | 珠海格力电器股份有限公司 | Mains frequency detection circuit, method, storage medium and processor |
| CN108037359A (en) * | 2017-11-21 | 2018-05-15 | 北京智芯微电子科技有限公司 | A kind of grid frequency measurement circuit for eliminating flickering and m-Acetyl chlorophosphonazo interference |
| CN109030937A (en) * | 2018-08-13 | 2018-12-18 | 珠海格力电器股份有限公司 | Supply frequency detection circuit, air-conditioning and grid-connected system |
| CN111181548A (en) * | 2020-01-16 | 2020-05-19 | 山东美创生物科技股份有限公司 | Counting and sampling circuit for mosquito killing equipment |
| CN112710897A (en) * | 2020-12-07 | 2021-04-27 | 广东电网有限责任公司韶关供电局 | Frequency measuring circuit |
-
2017
- 2017-09-04 CN CN201721132843.2U patent/CN207198238U/en active Active
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107589298A (en) * | 2017-09-04 | 2018-01-16 | 珠海格力电器股份有限公司 | Mains frequency detection circuit, method, storage medium and processor |
| CN108037359A (en) * | 2017-11-21 | 2018-05-15 | 北京智芯微电子科技有限公司 | A kind of grid frequency measurement circuit for eliminating flickering and m-Acetyl chlorophosphonazo interference |
| CN108037359B (en) * | 2017-11-21 | 2020-04-24 | 北京智芯微电子科技有限公司 | Power grid frequency measuring circuit for eliminating flicker and inter-harmonic interference |
| CN109030937A (en) * | 2018-08-13 | 2018-12-18 | 珠海格力电器股份有限公司 | Supply frequency detection circuit, air-conditioning and grid-connected system |
| CN109030937B (en) * | 2018-08-13 | 2024-02-06 | 珠海格力电器股份有限公司 | Power frequency detection circuit, air conditioner and grid-connected system |
| CN111181548A (en) * | 2020-01-16 | 2020-05-19 | 山东美创生物科技股份有限公司 | Counting and sampling circuit for mosquito killing equipment |
| CN111181548B (en) * | 2020-01-16 | 2022-11-22 | 山东美创生物科技股份有限公司 | Counting and sampling circuit for mosquito killing equipment |
| CN112710897A (en) * | 2020-12-07 | 2021-04-27 | 广东电网有限责任公司韶关供电局 | Frequency measuring circuit |
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