CN204424866U - A kind of current-limiting protection circuit and current-limiting protection device - Google Patents
A kind of current-limiting protection circuit and current-limiting protection device Download PDFInfo
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- CN204424866U CN204424866U CN201520096325.4U CN201520096325U CN204424866U CN 204424866 U CN204424866 U CN 204424866U CN 201520096325 U CN201520096325 U CN 201520096325U CN 204424866 U CN204424866 U CN 204424866U
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Abstract
The application provides a kind of current-limiting protection circuit and current-limiting protection device, by the first comparator, the detected signal received and the first preset value are compared, when detected signal is more than the first preset value, first comparator output low level signal, and input the in-phase input end of the second comparator, and then compare with the pwm signal that the inverting input of the second comparator receives; And the pwm signal making machine in running order is high level, now the second comparator output low level signal, makes current-limiting protection circuit output low level signal; The low level signal that current-limiting protection circuit exports can control drive circuit and block pwm signal, and the switching tube in drive circuit control appliance can be made in time to turn off, and avoids the system failure during grid transient adopting current foldback circuit to bring to shut down.
Description
Technical field
The utility model relates to grid-connected technical field, particularly relates to a kind of current-limiting protection circuit and current-limiting protection device.
Background technology
In photovoltaic parallel in system, when line voltage there is instantaneous distortion, fall or phase hit time, often can cause the vibration of PV input current, sudden change, and then often cause the overcurrent protection in system.
But when overcurrent protection starts, the electric current in relevant device has exceeded its limited field, thus can cause and shut down and can corresponding failure be quoted.The problem that when therefore adopting current foldback circuit to there is grid transient, system failure outage rate is high.
In fact the described equipment in photovoltaic parallel in system generally adopts drive circuit to carry out the control of switching tube; as in a device electric current raise time; the switching tube that described drive circuit can control wherein in time turns off, and system failure during above-mentioned grid transient can be avoided to shut down.So prior art lacks the technology that described drive circuit can be made in time to control the shutoff of described switching tube.
Utility model content
In view of this, the utility model provides a kind of current-limiting protection circuit and current-limiting protection device, to solve the problem that prior art lacks the technology that drive circuit control appliance switching tube can be made in time to turn off.
To achieve these goals, the technical scheme that provides of the utility model embodiment is as follows:
A kind of current-limiting protection circuit, is applied to photovoltaic parallel in system, comprises:
In-phase input end receives the first comparator of the first preset value; The inverting input of described first comparator is the input of described current-limiting protection circuit;
The first resistance that one end is all connected with the output of described first comparator and the second resistance; The other end of described first resistance receives the first voltage signal;
The second comparator that in-phase input end is connected with the output of described first comparator; The inverting input of described second comparator receives pwm signal; The output of described second comparator is connected with the other end of described second resistance;
The first diode that negative pole is connected with the output of described second comparator;
The 3rd resistance that one end is connected with the positive pole of described first diode; The other end of described 3rd resistance receives the second voltage signal; The tie point of the positive pole of described 3rd resistance and described first diode is the output of described current-limiting protection circuit.
Preferably, also comprise: the 3rd comparator that in-phase input end is connected with the inverting input of described first comparator; The inverting input of described 3rd comparator receives the second preset value; The output of described 3rd comparator is connected with the in-phase input end of the output of described first comparator and described second comparator.
Preferably, also comprise:
The second diode that negative pole is all connected with the inverting input of described second comparator and the 3rd diode; The positive pole of described second diode and the 3rd diode receives different pwm signals respectively;
The 4th resistance that one end is connected with the negative pole of described second diode and the negative pole of the 3rd diode; The other end ground connection of described 4th resistance.
Preferably, also comprise: positive pole is all connected with the inverting input of described second comparator and receives the second diode and the 3rd diode of tertiary voltage signal; The negative pole of described second diode and the 3rd diode receives different pwm signals respectively.
A kind of current-limiting protection device, be applied to the dcdc converter in photovoltaic parallel in system, described current-limiting protection device comprises:
Input is as the input of described current-limiting protection device, the current sampling circuit that is connected with the input of described dcdc converter;
Current-limiting protection circuit described above, the input of described current-limiting protection circuit is connected with the output of described current sampling circuit;
The drive circuit that input is connected with the output of described current-limiting protection circuit; Described drive circuit receives described pwm signal; The output of described drive circuit is the output of described current-limiting protection device, is connected with described dcdc converter.
A kind of current-limiting protection device, be applied to the DCAC converter in photovoltaic parallel in system, described current-limiting protection device comprises:
Input is as the input of described current-limiting protection device, the current sampling circuit that is connected with the input of described DCAC converter;
Current-limiting protection circuit described above, the input of described current-limiting protection circuit is connected with the output of described current sampling circuit;
The drive circuit that input is connected with the output of described current-limiting protection circuit; Described drive circuit receives described pwm signal; The output of described drive circuit is the output of described current-limiting protection device, is connected with described DCAC converter.
The application provides a kind of current-limiting protection circuit, by the first comparator, the detected signal received and the first preset value are compared, when described detected signal exceedes described first preset value, described first comparator output low level signal, and input the in-phase input end of the second comparator, and then compare with the pwm signal that the inverting input of described second comparator receives; And the described pwm signal making machine in running order is high level, now described second comparator output low level signal, makes described current-limiting protection circuit output low level signal; The low level signal that described current-limiting protection circuit exports can control drive circuit and block described pwm signal; the switching tube in described drive circuit control appliance can be made in time to turn off, avoid the system failure during grid transient adopting current foldback circuit to bring to shut down.
Accompanying drawing explanation
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only embodiment of the present utility model, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to the accompanying drawing provided.
A kind of current-limiting protection circuit structure chart that Fig. 1 provides for the embodiment of the present application;
A kind of current-limiting protection circuit structure chart that Fig. 2 provides for another embodiment of the application;
A kind of current-limiting protection circuit structure chart that Fig. 3 provides for another embodiment of the application;
A kind of current-limiting protection circuit structure chart that Fig. 4 provides for another embodiment of the application;
A kind of current-limiting protection circuit structure chart that Fig. 5 provides for another embodiment of the application;
A kind of current-limiting protection circuit structure chart that Fig. 6 provides for another embodiment of the application;
A kind of current-limiting protection device schematic diagram that Fig. 7 provides for another embodiment of the application;
A kind of current-limiting protection device schematic diagram that Fig. 8 provides for another embodiment of the application;
A kind of current-limiting protection device schematic diagram that Fig. 9 provides for another embodiment of the application.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.
The utility model provides a kind of current-limiting protection circuit, is applied to photovoltaic parallel in system, to solve the problem that prior art lacks the technology that drive circuit control appliance switching tube can be made in time to turn off.
Concrete, as shown in Figure 1, described current-limiting protection circuit comprises:
In-phase input end receives the first comparator U1 of the first preset value Vop; The inverting input of the first comparator U1 is the input of described current-limiting protection circuit;
The first resistance R1 that one end is all connected with the output of the first comparator U1 and the second resistance R2; The other end of the first resistance R1 receives the first voltage signal V1;
The second comparator U2 that in-phase input end is connected with the output of the first comparator U1; The inverting input of the second comparator U2 receives pwm signal; The output of the second comparator U2 is connected with the other end of the second resistance R2;
The first diode D1 that negative pole is connected with the output of the second comparator U2;
The 3rd resistance R3 that one end is connected with the positive pole of the first diode D1; The other end of the 3rd resistance R3 receives the second voltage signal V2; The tie point of the positive pole of the 3rd resistance R3 and the first diode D1 is the output of described current-limiting protection circuit.
Concrete operation principle is:
Under normal mode, the input of described current-limiting protection circuit, the input signal Vin that also namely the inverting input of the first comparator U1 receives is less than the first preset value Vop that the first comparator U1 in-phase input end receives, and the first comparator U1 exports as high level; And the first voltage signal V1 that pwm signal high level voltage is received by the first resistance R1 lower than the second comparator U2, the output signal of the second comparator U2 is high level, then the output signal of described current-limiting protection circuit is high level signal, and fault-free occurs.
Need to start the course of work of current-limiting protection and be: the input signal Vin that the inverting input of the first comparator U1 receives is greater than the first preset value Vop that the first comparator U1 in-phase input end receives, and the first comparator U1 exports as low level; And the pwm signal making machine in running order is now high level, the output signal of the second comparator U2 is low level; The low level signal that described current-limiting protection circuit exports can control drive circuit and block pwm signal; the switching tube in described drive circuit control appliance can be made in time to turn off, avoid the system failure during grid transient adopting current foldback circuit to bring to shut down.
What deserves to be explained is; the input signal Vin received when the input of described current-limiting protection circuit returns to normal mode, and pwm signal becomes low level, and the output of the second comparator U2 is high level; protection cut-off, started to return to normal mode of operation in the pulse period of next pwm signal.This protected mode can not increase the switching frequency of switching tube, and with comparator type realize protect speed comparatively prior art is faster.
The utility model another embodiment still provides another current-limiting protection circuit, as shown in Figure 1, comprising:
In-phase input end receives the first comparator U1 of the first preset value Vop; The inverting input of the first comparator U1 is the input of described current-limiting protection circuit;
The first resistance R1 that one end is all connected with the output of the first comparator U1 and the second resistance R2; The other end of the first resistance R1 receives the first voltage signal V1;
The second comparator U2 that in-phase input end is connected with the output of the first comparator U1; The inverting input of the second comparator U2 receives pwm signal; The output of the second comparator U2 is connected with the other end of the second resistance R2;
The first diode D1 that negative pole is connected with the output of the second comparator U2;
The 3rd resistance R3 that one end is connected with the positive pole of the first diode D1; The other end of the 3rd resistance R3 receives the second voltage signal V2; The tie point of the positive pole of the 3rd resistance R3 and the first diode D1 is the output of described current-limiting protection circuit.
Current-limiting protection circuit described in the present embodiment as shown in Figure 2, also comprises: the 3rd comparator U3 that in-phase input end is connected with the inverting input of the first comparator U1; The inverting input of the 3rd comparator U3 receives the second preset value Vlp; The output of the 3rd comparator U3 is connected with the in-phase input end of the output of the first comparator U1 and the second comparator U2.
When described current-limiting protection circuit only includes the first comparator U1 and the second comparator U2; described current-limiting protection circuit is applicable to the detection to direct current, and described current-limiting protection circuit is also only applicable to protect the equipment flowing through direct current (as received the dcdc converter of PV input current).
But in photovoltaic parallel in system; when line voltage there is instantaneous distortion, fall or phase hit time; not only often can cause vibration, the sudden change of PV input current, also likely can cause vibration, the sudden change of grid-connected current simultaneously, and then often cause the overcurrent protection in system.
And the current-limiting protection circuit described in the present embodiment also comprises the 3rd comparator U3; for input voltage provides the comparing element of a lowest threshold (i.e. the second preset value Vlp); namely be applicable to the detection to alternating current, described current-limiting protection circuit is also applicable to be protected the equipment flowing through alternating current (as exported the DCAC converter of grid-connected voltage).As the first comparator U1 and any one output low level signal of the 3rd comparator U3; the output signal of the second comparator U2 can be made to be low level; and then control drive circuit blocks pwm signal; make the switching tube in described drive circuit control appliance turn off in time, avoid the system failure during grid transient adopting current foldback circuit to bring to shut down.
The utility model another embodiment still provides another current-limiting protection circuit, as shown in Figure 1, comprising:
In-phase input end receives the first comparator U1 of the first preset value Vop; The inverting input of the first comparator U1 is the input of described current-limiting protection circuit;
The first resistance R1 that one end is all connected with the output of the first comparator U1 and the second resistance R2; The other end of the first resistance R1 receives the first voltage signal V1;
The second comparator U2 that in-phase input end is connected with the output of the first comparator U1; The inverting input of the second comparator U2 receives pwm signal; The output of the second comparator U2 is connected with the other end of the second resistance R2;
The first diode D1 that negative pole is connected with the output of the second comparator U2;
The 3rd resistance R3 that one end is connected with the positive pole of the first diode D1; The other end of the 3rd resistance R3 receives the second voltage signal V2; The tie point of the positive pole of the 3rd resistance R3 and the first diode D1 is the output of described current-limiting protection circuit.
Current-limiting protection circuit described in the present embodiment as shown in Figure 3 or Figure 4, also comprises:
The second diode D2 that negative pole is all connected with the inverting input of the second comparator U2 and the 3rd diode D3; The positive pole of the second diode D2 and the 3rd diode D3 receives different pwm signals, respectively as PWM1 and PWM2;
The 4th resistance R4 that one end is connected with the negative pole of the second diode D2 and the negative pole of the 3rd diode D3; The other end ground connection of the 4th resistance R4.
After there is current-limiting protection, only have the next cycle after two pwm signals (PWM1, PWM2) and logic are low, described current-limiting protection just can disappear.
The utility model another embodiment still provides another current-limiting protection circuit, as shown in Figure 1, comprising:
In-phase input end receives the first comparator U1 of the first preset value Vop; The inverting input of the first comparator U1 is the input of described current-limiting protection circuit;
The first resistance R1 that one end is all connected with the output of the first comparator U1 and the second resistance R2; The other end of the first resistance R1 receives the first voltage signal V1;
The second comparator U2 that in-phase input end is connected with the output of the first comparator U1; The inverting input of the second comparator U2 receives pwm signal; The output of the second comparator U2 is connected with the other end of the second resistance R2;
The first diode D1 that negative pole is connected with the output of the second comparator U2;
The 3rd resistance R3 that one end is connected with the positive pole of the first diode D1; The other end of the 3rd resistance R3 receives the second voltage signal V2; The tie point of the positive pole of the 3rd resistance R3 and the first diode D1 is the output of described current-limiting protection circuit.
Current-limiting protection circuit described in the present embodiment as shown in Figure 5 or Figure 6, also comprises: positive pole is all connected with the inverting input of the second comparator U2 and receives the second diode D2 and the 3rd diode D3 of tertiary voltage signal V3; The negative pole of the second diode D2 and the 3rd diode D3 receives different pwm signals, respectively as PWM1 and PWM2.
After there is current-limiting protection, only have the next cycle after two pwm signals (PWM1, PWM2) phases or logic are low, described current-limiting protection just can disappear.
The utility model another embodiment still provides a kind of current-limiting protection device, be applied to the dcdc converter in photovoltaic parallel in system, described current-limiting protection device as shown in Figure 7, comprising:
Input is as the input of described current-limiting protection device, the current sampling circuit 101 that is connected with the input of described dcdc converter;
Current-limiting protection circuit 102 described in above-mentioned first embodiment, the input of current-limiting protection circuit 102 is connected with the output of current sampling circuit 101;
The drive circuit 103 that input is connected with the output of current-limiting protection circuit 102; Drive circuit 103 receives described pwm signal; The output of drive circuit 103 is the output of described current-limiting protection device, is connected with described dcdc converter.
Concrete operation principle is:
When current-limiting protection circuit 102 exports as high level, do not affect the normal PWM of drive circuit 103 and drive logic; When current-limiting protection circuit 102 output low level, the described pwm signal that can be received by drive circuit 103 fast drags down to be protected, and recover the pulse period of the next pwm signal normally at electric current, described current-limiting protection just can disappear.
The utility model another embodiment still provides a kind of current-limiting protection device, be applied to the DCAC converter in photovoltaic parallel in system, described current-limiting protection device as shown in Figure 8, comprising:
Input is as the input of described current-limiting protection device, the current sampling circuit 201 that is connected with the input of described DCAC converter;
Current-limiting protection circuit 202 described in above-mentioned second embodiment, the input of current-limiting protection circuit 202 is connected with the output of current sampling circuit 201;
The drive circuit 203 that input is connected with the output of current-limiting protection circuit 202; Drive circuit 203 receives described pwm signal; The output of drive circuit 203 is the output of described current-limiting protection device, is connected with described DCAC converter.
Concrete operation principle is same as the previously described embodiments, repeats no longer one by one herein.
What deserves to be explained is, in concrete practical application, in photovoltaic parallel in system, receive the dcdc converter of PV input current; and export the DCAC converter of grid-connected current; current-limiting protection device can be connected with simultaneously, as shown in Figure 9, can simultaneously for two converters provide current-limiting protection.
In the utility model, each embodiment adopts the mode of going forward one by one to describe, and what each embodiment stressed is the difference with other embodiments, between each embodiment identical similar portion mutually see.For device disclosed in embodiment, because it corresponds to the method disclosed in Example, so description is fairly simple, relevant part illustrates see method part.
Below be only preferred implementation of the present utility model, those skilled in the art understood or realizes the utility model.To be apparent to one skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein when not departing from spirit or scope of the present utility model, can realize in other embodiments.Therefore, the utility model can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.
Claims (6)
1. a current-limiting protection circuit, is characterized in that, is applied to photovoltaic parallel in system, comprising:
In-phase input end receives the first comparator of the first preset value; The inverting input of described first comparator is the input of described current-limiting protection circuit;
The first resistance that one end is all connected with the output of described first comparator and the second resistance; The other end of described first resistance receives the first voltage signal;
The second comparator that in-phase input end is connected with the output of described first comparator; The inverting input of described second comparator receives pwm signal; The output of described second comparator is connected with the other end of described second resistance;
The first diode that negative pole is connected with the output of described second comparator;
The 3rd resistance that one end is connected with the positive pole of described first diode; The other end of described 3rd resistance receives the second voltage signal; The tie point of the positive pole of described 3rd resistance and described first diode is the output of described current-limiting protection circuit.
2. current-limiting protection circuit according to claim 1, is characterized in that, also comprises: the 3rd comparator that in-phase input end is connected with the inverting input of described first comparator; The inverting input of described 3rd comparator receives the second preset value; The output of described 3rd comparator is connected with the in-phase input end of the output of described first comparator and described second comparator.
3. current-limiting protection circuit according to claim 1 and 2, is characterized in that, also comprises:
The second diode that negative pole is all connected with the inverting input of described second comparator and the 3rd diode; The positive pole of described second diode and the 3rd diode receives different pwm signals respectively;
The 4th resistance that one end is connected with the negative pole of described second diode and the negative pole of the 3rd diode; The other end ground connection of described 4th resistance.
4. current-limiting protection circuit according to claim 1 and 2, is characterized in that, also comprises: positive pole is all connected with the inverting input of described second comparator and receives the second diode and the 3rd diode of tertiary voltage signal; The negative pole of described second diode and the 3rd diode receives different pwm signals respectively.
5. a current-limiting protection device, is characterized in that, is applied to the dcdc converter in photovoltaic parallel in system, and described current-limiting protection device comprises:
Input is as the input of described current-limiting protection device, the current sampling circuit that is connected with the input of described dcdc converter;
Current-limiting protection circuit according to claim 1, the input of described current-limiting protection circuit is connected with the output of described current sampling circuit;
The drive circuit that input is connected with the output of described current-limiting protection circuit; Described drive circuit receives described pwm signal; The output of described drive circuit is the output of described current-limiting protection device, is connected with described dcdc converter.
6. a current-limiting protection device, is characterized in that, be applied to the DCAC converter in photovoltaic parallel in system, described current-limiting protection device comprises:
Input is as the input of described current-limiting protection device, the current sampling circuit that is connected with the input of described DCAC converter;
Current-limiting protection circuit according to claim 2, the input of described current-limiting protection circuit is connected with the output of described current sampling circuit;
The drive circuit that input is connected with the output of described current-limiting protection circuit; Described drive circuit receives described pwm signal; The output of described drive circuit is the output of described current-limiting protection device, is connected with described DCAC converter.
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| CN201520096325.4U CN204424866U (en) | 2015-02-10 | 2015-02-10 | A kind of current-limiting protection circuit and current-limiting protection device |
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| CN201520096325.4U CN204424866U (en) | 2015-02-10 | 2015-02-10 | A kind of current-limiting protection circuit and current-limiting protection device |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105429107A (en) * | 2015-12-01 | 2016-03-23 | 珠海格力电器股份有限公司 | Phase current protection circuit for inverter |
| CN106787661A (en) * | 2017-02-24 | 2017-05-31 | 华远电气股份有限公司 | Frequency converter and its wave limiting protection circuit |
| CN109067155A (en) * | 2018-07-10 | 2018-12-21 | 深圳市华星光电半导体显示技术有限公司 | Current foldback circuit, method and the display panel of DC-DC conversion circuit |
| CN109524941A (en) * | 2018-12-29 | 2019-03-26 | 北京汇能精电科技股份有限公司 | Phase current foldback circuit and photovoltaic controller |
-
2015
- 2015-02-10 CN CN201520096325.4U patent/CN204424866U/en active Active
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105429107A (en) * | 2015-12-01 | 2016-03-23 | 珠海格力电器股份有限公司 | Phase current protection circuit for inverter |
| CN106787661A (en) * | 2017-02-24 | 2017-05-31 | 华远电气股份有限公司 | Frequency converter and its wave limiting protection circuit |
| CN106787661B (en) * | 2017-02-24 | 2023-10-13 | 华远电气股份有限公司 | Frequency converter and wave-by-wave current-limiting protection circuit thereof |
| CN109067155A (en) * | 2018-07-10 | 2018-12-21 | 深圳市华星光电半导体显示技术有限公司 | Current foldback circuit, method and the display panel of DC-DC conversion circuit |
| WO2020010697A1 (en) * | 2018-07-10 | 2020-01-16 | 深圳市华星光电半导体显示技术有限公司 | Overcurrent protection circuit and method for dc-dc conversion circuit, and display panel |
| CN109067155B (en) * | 2018-07-10 | 2020-04-07 | 深圳市华星光电半导体显示技术有限公司 | Overcurrent protection circuit and method of DC-DC conversion circuit and display panel |
| CN109524941A (en) * | 2018-12-29 | 2019-03-26 | 北京汇能精电科技股份有限公司 | Phase current foldback circuit and photovoltaic controller |
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