CN202268709U - Photovoltaic broken network relay zero crossing control circuit and system - Google Patents
Photovoltaic broken network relay zero crossing control circuit and system Download PDFInfo
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- CN202268709U CN202268709U CN2011203704075U CN201120370407U CN202268709U CN 202268709 U CN202268709 U CN 202268709U CN 2011203704075 U CN2011203704075 U CN 2011203704075U CN 201120370407 U CN201120370407 U CN 201120370407U CN 202268709 U CN202268709 U CN 202268709U
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Abstract
An embodiment of the utility model provides a photovoltaic broken network relay zero crossing control circuit and a system, which is used for controlling connection or disconnection of an inverter side circuit and a power grid side circuit when zero crossing of inverter current occurs. The photovoltaic broken network relay zero crossing control circuit comprises an inverter output current detection circuit, a main control digital signal processor (DSP) circuit, a relay driving circuit and a relay circuit. The inverter output current detection circuit is used for detecting output current of the inverter side circuit and outputting a current signal which is in proportion to the output current of the inverter side circuit. The main control DSP circuit is used for receiving the current signal which is in proportion to the output current of the inverter side circuit, detecting a zero crossing point of the current signal which is in proportion to the output current of the inverter side circuit and outputting a level signal. The relay driving circuit is used for enabling the level signal to be converted into a switch control signal and controlling a relay driving signal to connect or disconnect the relay circuit. The relay circuit is used for controlling connection or disconnection of the inverter side circuit and the power grid side circuit through connection or disconnection of the relay circuit.
Description
Technical field
The utility model relates to field of electric control, concrete a kind of photovoltaic suspension relay zero-crossing control circuit and the system of relating to.
Background technology
Existing photovoltaic DC-to-AC converter all need insert electrical network through switch control during use.Photovoltaic DC-to-AC converter below the 15KW is because the reason of cost and volume generally adopts relay to insert electrical network as switch.
Relay is made up of iron core, coil, armature, contact reed etc. as the Primary Component of photovoltaic DC-to-AC converter.As long as add certain voltage at the coil two ends, will flow through certain electric current in the coil, thereby produce galvanomagnetic effect, make the normally opened contact adhesive.Behind coil blackout, galvanomagnetic effect disappears, and normally opened contact discharges.Usually adopt the access or the disconnection of two group relay control inverter sides and grid side, when breaking down for one group, another group can also be cut off electrical network, guarantees the fail safe of control.As shown in Figure 1, K1, K3, K5 and K7 are group relaies, and K2, K4, K6 and K8 are another group relaies; Be connected inverter side L1 and grid side AC_L1 after K1 and the K2 series connection; K3 and K4 series connection back is connected inverter side L2 and grid side AC_L2, K5 be connected inverter side L3 and grid side AC_L3 after K6 connects, K7 and K8 be connected in series inverter side center line N and grid side center line AC_N; The shared control signal control of every group relay; K1, K3, K5 and K7 adopt JDK1 to control, and K2, K4, K6 and K8 employing JDK2 control are through JDK1 and JDK2 control inverter side three-phase input L1, L2, L3 and center line N and grid side access or disconnection simultaneously.
Adopt the control of this kind scheme,, can cause relay when inverter output current zero passage, not turn on and off because there is time delay in the signals transmission.When having electric current to break off, the contact of relay tends to produce the arcing phenomenon, causes its contact that oxidation or impaired takes place, and long-time the use can make the relay contact adhesion, makes inverter can not break off the connection of electrical network, is easy to generate security incident.Simultaneously; Adopt a control signal to control a group relay, promptly a control signal is controlled three-phase input and center line simultaneously, and owing to three-phase input and center line in the inverter side circuit is not to arrive current zero-crossing point simultaneously; Can cause in switch; Possibly have only one tunnel relay is when current zero-crossing point, to move, and other are not when current zero-crossing point, to move, and have contact oxidation or impaired problem.
The utility model content
The utility model embodiment provides a kind of photovoltaic suspension relay zero-crossing control circuit, and inverter side circuit and grid side circuit insert or disconnection when being used to be controlled at the inverter current zero passage, prolongs relay useful life and increases circuit safety property.
The utility model embodiment provides a kind of three-phase photovoltaic suspension relay zero-crossing control system again; Be used to adopt independently each relay of control signal control; Guarantee that each relay contact all can move in inverter side circuit output current zero passage constantly, prolong relay useful life and increase circuit safety property.
A kind of photovoltaic suspension relay zero-crossing control circuit that provides according to the utility model embodiment; Be used for the access or the disconnection of control inverter lateral circuit and grid side circuit; It is characterized in that; Comprise the inverter output current detection circuit, master control Digital Signal Processing DSP circuit, relay drive circuit and relay circuit
Said inverter output current detection circuit is used to detect the output current of said inverter side circuit, the proportional current signal of output current of output one and inverter side circuit;
Said master control DSP circuit is used to receive said and the proportional current signal of the output current inverter side circuit; Detect the zero crossing of the proportional current signal of output current of said and inverter side circuit; And said zero crossing set first delay time; After said first delay time arrives, outputs level signals;
Said relay drive circuit is used for converting said level signal to switch controlling signal, and the control relay drive signal is switched on or switched off said relay circuit;
Said relay circuit is used for being switched on or switched off through it the access or disconnection of control inverter lateral circuit and grid side circuit.
According to a kind of three-phase photovoltaic suspension relay zero-crossing control system that the another embodiment of the utility model provides, the inverter side circuit is connected with the grid side circuit with a center line through three-phase output,
Adopt two group relay groups that said inverter side circuit is connected control with said grid side circuit; Each self-contained four relay of every group relay group are controlled three-phase output and center line four road signals respectively; Two corresponding in the signal of every road relay series connection are provided with, and said each relay adopts one and independently controls like the described photovoltaic suspension of the utility model embodiment relay zero-crossing control circuit.
Can find out that from above technical scheme the utility model embodiment has the following advantages:
(1) detects behind the output current zero crossing outputs level signals behind first delay time; Outputs level signals to said relay circuit is switched on or switched off and has second delay time; First delay time and second delay time are arranged to the half period time of inverter side electric current; Can guarantee that relay is switched on or switched off at the output current zero crossing; Avoid the arcing phenomenon, relay contact can not turn on and off when electric current is arranged and produce contact oxidation and adhesion, has guaranteed the fail safe of relay control;
(2) each relay adopts independent control signal to carry out current zero-crossing point conducting and shutoff, can guarantee that each road relay all is switched on or switched off when zero current, has guaranteed the fail safe of each road relay control.
Description of drawings
Fig. 1 is a prior art network relay structural representation;
Fig. 2 is the theory diagram of the utility model embodiment photovoltaic suspension relay zero-crossing control circuit;
Fig. 3 is the theory diagram of inverter output current detection circuit in the utility model embodiment photovoltaic suspension relay zero-crossing control circuit;
Fig. 4 is the circuit theory diagrams of inverter output current detection circuit in the utility model embodiment photovoltaic suspension relay zero-crossing control circuit;
Fig. 5 is the theory diagram of the utility model embodiment photovoltaic suspension relay zero-crossing control circuit repeat circuit drive circuit;
Fig. 6 is the circuit theory diagrams of the utility model embodiment photovoltaic suspension relay zero-crossing control circuit repeat circuit drive circuit;
Fig. 7 is the utility model embodiment three-phase photovoltaic suspension relay zero-crossing control system structural representation.
Embodiment
The utility model embodiment provides a kind of photovoltaic suspension relay zero-crossing control circuit, and inverter side circuit and grid side circuit insert or disconnection when being used to be controlled at the inverter current zero passage.
The utility model embodiment provides a kind of photovoltaic suspension relay zero-crossing control system again, is used to adopt independently each relay of control signal control, guarantees that each relay contact all can move in inverter side circuit output current zero passage constantly.
Be described in detail below in conjunction with the several preferred embodiments of accompanying drawing, but the utility model is not restricted to these embodiment the utility model.The utility model is contained substituting of making on any marrow and scope at the utility model, modification, equivalent method and scheme.Understand for the public is had completely the utility model, in following the utility model preferred embodiment, specified concrete details, and do not had the description of these details also can understand the utility model fully for a person skilled in the art.In addition, cause unnecessary obscuring, do not specify well-known method, process, flow process, element and circuit etc. for fear of essence to the utility model.
Referring to Fig. 2; Be depicted as the theory diagram of the utility model embodiment three-phase photovoltaic suspension relay zero-crossing control circuit; Comprise inverter output current detection circuit 20; Master control DSP circuit 30, relay drive circuit 40 and relay circuit 10, inverter output current detection circuit 20 are used to detect the output current IA of inverter side circuit, the proportional current signal IA ' of output current of output one and inverter side circuit; Master control DSP circuit is used to receive and the proportional current signal IA ' of the output current of inverter side circuit; Detect zero crossing with the proportional current signal IA ' of the output current of inverter side circuit; And zero crossing set the first delay time t1; After the first delay time t1 arrives, outputs level signals RLY1; Relay drive circuit is used for converting level signal RLY1 to switch controlling signal, and control relay drive signal JDK1 is switched on or switched off coil in the relay circuit 10; Relay circuit 10 is used for being switched on or switched off through it the access or disconnection of control inverter lateral circuit 50 and grid side circuit 60.
Pass through present embodiment; The inverter side circuit is connected with the grid side circuit through relay circuit; Set a delay time when the proportional output current zero crossing of detected and inverter side output current through master control DSP circuit; Arrive back level signal of output at delay time and remove control relay, can guarantee that relay is closed or break off when next output current zero crossing, avoided relay closed or arcing phenomenon of producing when breaking off when electric current is arranged; Make that the relay contact oxidation is impaired, can guarantee the safe handling of relay circuit.
Particularly, specify the implementation process of the utility model embodiment photovoltaic suspension relay zero-crossing control circuit below in conjunction with Fig. 3 to Fig. 6.
Referring to Fig. 3; Be depicted as the theory diagram of inverter output current detection circuit in the utility model embodiment photovoltaic suspension relay zero-crossing control circuit; Inverter current testing circuit 20 comprises Hall current sensor 21, is used to extract the output current I of said inverter side circuit
A, and export one with the proportional voltage signal V of output current of said inverter side circuit
ABleeder circuit 22 is used for said voltage signal is carried out dividing potential drop V
A, output branch pressure voltage signal V
A'; Homophase follow circuit 23 is used for said branch pressure voltage signal V
A' carry out that homophase is followed and impedance matching, the proportional current signal I of output current of output and inverter side circuit
A'.
The concrete application example of inverter output current detection circuit 20 is referring to Fig. 4, and U3 is the Hall current sensor of PCB plug-in mounting, I
A_INAnd I
A_OUTBe the cabling of inverter side circuit on pcb board, 1 pin of U3,2 pin, 3 pin are the power supply signals that connect positive and negative 15V, output of 4 pin and the proportional voltage signal V of inverter output current
A, after resistance R 2, the step-down of R27 dividing potential drop, output branch pressure voltage signal V
A', branch pressure voltage signal V
A' homophase of following amplifier U2-A through homophase again follows, carry out impedance matching after, the proportional current signal I of output current of output and inverter side circuit
A'.
The proportional current signal I of the output current with the inverter side circuit through 20 outputs of inverter output current detection circuit
A' inputing to master control DSP circuit 30, the concrete course of work of master control DSP circuit 30 is: judge whether to want conducting or turn-off relay; When needing conducting or turn-offing relay, detect and the proportional current signal I of the output current of inverter side circuit
A' zero crossing; After detecting inverter output current zero crossing, set the first delay time t1, after the first delay time t1 arrives, outputs level signals RLY1.Action has the second delay time t2 because master control DSP outputs level signals RLY1 converts relay contact to; Therefore t1+t2 is arranged to the half period time of inverter side circuit output current signal; Can guarantee that relay circuit opens or turn-off when next current zero-crossing point, thereby make relay when electric current is zero, be switched on or switched off, avoid the arcing phenomenon; The contact can oxidation and adhesion yet, improves fail safe.
The level signal RLY1 of master control DSP circuit 30 outputs exports relay drive circuit 40 to and handles; Relay drive circuit 40 further comprises: optocoupler 41, fly-wheel diode circuit 42, pressure limiting circuit 43 and switching circuit 44; Optocoupler 41 has former limit 411 and secondary 412, and former limit 411 1 inputs receive the first power supply voltage signal V
CC1, another input receives said level signal RLY1, secondary 412 input termination second source voltage signal V
CC2, secondary 412 output termination switching circuits 44 control ends are used for converting level signal RLY1 to switch controlling signal, and control relay drive signal JDK1 is switched on or switched off relay circuit 10; The said second source voltage signal of fly-wheel diode circuit 42 1 input terminations V
CC2, the other end is connected with relay circuit 10, is used for absorbing relay circuit 10 coils and is switched to the induced voltage that produces when breaking off; Pressure limiting circuit 43 1 ends are connected with fly-wheel diode circuit 42 outputs, and the other end connects an end of switching circuit 44, are used for limiting the voltage of relay circuit 10 coils; The other end ground connection of switching circuit 44 is through the conducting of switching circuit 44 and being switched on or switched off of shutoff control relay circuit 10.
The concrete application example of relay drive circuit 40 is referring to Fig. 6, and RLY1 is the level signal from master control DSP circuit 30, and level signal RLY1 converts connection or the disconnection that switch controlling signal can control relay circuit 10 to through optocoupler 41.The first input supply voltage V
CC1The 5V voltage of input is through former limit 411 1 ends of resistance R 3 input optocouplers 41; The other end on level signal RLY1 input optocoupler 41 former limits 411, when RLY1 when low, the former limit 411 of optocoupler 41 has electric current to flow through and conducting; Secondary 412 conductings of optocoupler 41, second source voltage V
CC2The 12V voltage of input is through the metal-oxide-semiconductor field effect t MOSFET Q2 conducting of resistance R 6 controls as switching circuit 44, and relay drive signal JDK1 makes relay circuit 10 to conduct.Resistance R 8, R9, R10 and capacitor C 4 parallel connections are provided with the voltage of forming coil in the pressure limiting circuit 43 restriction relay circuits 10, and when relay circuit 10 must conduct, capacitor C 4 was equivalent to open circuit, second source voltage V
CC2Can load fully on the coil of relay circuit 10, after relay circuit 10 conductings, resistance R 8, R9, the 3V voltage drop arranged above the R10, make relay circuit 10 coil sustaining voltages have only 9V, make relay circuit 10 minimizing of when conducting, generating heat like this.When RLY1 signal when being high, the former limit 411 of optocoupler 41 is obstructed, and secondary 412 breaks off the MOSFET Q2 that makes as switching circuit 44 and also can break off, and relay drive signal JDK2 can't be carried in coil two ends in the relay circuit 10, and relay circuit 10 also can turn-off.Fly-wheel diode circuit 42 is composed in parallel by diode D1 and D2; And with relay circuit 10 in the coils from parallel connection of coils setting, coil is an inductive load in the relay circuit 10, MOSFET Q2 by be conducting to by the time; The coil two ends can produce higher induced voltage; Inverse parallel diode D1, D2 will absorb induced voltage, protection MOSFET Q2, thus guarantee the reliability in the circuit working process.
The photovoltaic suspension relay zero-crossing control circuit that the utility model embodiment provides can be applicable to three-phase or single-phase photovoltaic DC-to-AC converter circuit; Those skilled in the art are appreciated that simultaneously; Can be applicable to the inverter circuit of other types, the utility model does not limit the concrete application of the photovoltaic suspension relay zero-crossing control circuit that provides yet.
Referring to Fig. 7; Be depicted as the utility model embodiment three-phase photovoltaic suspension relay zero-crossing control system structural representation; Relay is as the switching device of inverter access electrical network, and its reliability design is extremely important, therefore; Adopt two group relay groups that the inverter side circuit is connected control with the grid side circuit; Each self-contained four relay of every group relay group are controlled three-phase output and center line four road signals respectively, and two corresponding in the signal of every road relay series connection are provided with, and said each relay adopts a photovoltaic suspension relay zero-crossing control circuit that independently provides like the utility model embodiment to control.Concrete is as shown in Figure 8, and K1, K3, K5, K7 are one group, and K2, K4, K6, K8 are one group, and the control of two group relaies can guarantee that a normal in addition group relay can guarantee inverter and electrical network disconnection when in the group relay out of order the time.K1 and K2 series connection back is connected inverter side L1 and grid side AC_L1, K3 be connected inverter side L2 and grid side AC_L2 after K4 connects, K5 be connected inverter side L3 and grid side AC_L3 after K6 connects; K7 and K8 be connected in series inverter side center line N and grid side center line AC_N, JDK1-JDK8 is respectively the drive signal of 8 relays, JDK1 control relay K1; JDK2 control relay K2, JDK3 control relay K3, JDK4 control relay K4; JDK5 control relay K5, JDK6 control relay K6, JDK7 control relay K7; JDK8 control relay K8, each relay adopts independently control signal, can guarantee that each relay contact all can move in inverter output current passing zero moment; Avoid relay contact oxidation or adhesion, improve the fail safe of control system.
One of ordinary skill in the art will appreciate that all or part of step that realizes in the foregoing description method is to instruct relevant hardware to accomplish through program; Described program can be stored in a kind of computer-readable recording medium; The above-mentioned storage medium of mentioning can be a read-only memory, disk or CD etc.
More than a kind of three-phase photovoltaic suspension relay zero-crossing control circuit, method and system that the utility model provided have been carried out detailed introduction; For one of ordinary skill in the art; Thought according to the utility model embodiment; The part that on embodiment and range of application, all can change, in sum, this description should not be construed as the restriction to the utility model.
Claims (6)
1. photovoltaic suspension relay zero-crossing control circuit; Be used for the access or the disconnection of control inverter lateral circuit and grid side circuit, it is characterized in that, comprise the inverter output current detection circuit; Master control Digital Signal Processing DSP circuit, relay drive circuit and relay circuit
Said inverter output current detection circuit is used to detect the output current of said inverter side circuit, the proportional current signal of output current of output one and inverter side circuit;
Said master control DSP circuit is used to receive said and the proportional current signal of the output current inverter side circuit; Detect the zero crossing of the proportional current signal of output current of said and inverter side circuit; And said zero crossing set first delay time; After said first delay time arrives, outputs level signals;
Said relay drive circuit is used for converting said level signal to switch controlling signal, and the control relay drive signal is switched on or switched off said relay circuit;
Said relay circuit is used for being switched on or switched off through it the access or disconnection of control inverter lateral circuit and grid side circuit.
2. photovoltaic suspension relay zero-crossing control circuit according to claim 1 is characterized in that said inverter output current detection circuit further comprises:
Hall current sensor is used to extract the output current of said inverter side circuit, and export one with the proportional voltage signal of output current of said inverter side circuit;
Bleeder circuit is used for said voltage signal is carried out dividing potential drop, output branch pressure voltage signal;
The homophase follow circuit is used for said branch pressure voltage signal carried out that homophase is followed and impedance matching, the proportional current signal of output current of output one and said inverter side circuit.
3. photovoltaic suspension relay zero-crossing control circuit according to claim 1 is characterized in that the concrete course of work of said master control DSP circuit is:
Receive said output current signal;
Judge whether to want conducting or turn-off relay;
When needing conducting or turn-offing relay, detect said output current zero crossing;
Said zero crossing is set a delay time, after delay time arrives, outputs level signals.
4. according to claim 1 or 3 described photovoltaic suspension relay zero-crossing control circuits, it is characterized in that, further comprise:
Exporting the delay time that said level signal is switched on or switched off to said relay circuit is second delay time, said first delay time and the said second delay time sum is arranged to the half period time of inverter side circuit output current signal.
5. photovoltaic suspension relay zero-crossing control circuit according to claim 1 is characterized in that said relay drive circuit further comprises: optocoupler, fly-wheel diode circuit, pressure limiting circuit and switching circuit,
Said optocoupler has former limit and secondary, and said former limit one input receives first power supply voltage signal, and another input receives said level signal,
Said secondary input termination second source voltage signal, the said switching circuit control end of said secondary output termination is used for converting said level signal to switch controlling signal, and the control relay drive signal is switched on or switched off said relay circuit;
The said second source voltage signal of said fly-wheel diode circuit one termination, the other end is connected with relay circuit, is used for absorbing said relay circuit coil and is switched to the induced voltage that produces when breaking off;
Said pressure limiting circuit one end is connected with said fly-wheel diode circuit output end, and the other end connects an end of said switching circuit, is used for limiting the voltage of said relay circuit coil;
The other end ground connection of said switching circuit is used for through the conducting of said switching circuit and being switched on or switched off of the shutoff said relay circuit of control.
6. three-phase photovoltaic suspension relay zero-crossing control system, the inverter side circuit is connected with the grid side circuit with a center line through three-phase output, it is characterized in that,
Adopt two group relay groups that said inverter side circuit is connected control with said grid side circuit; Each self-contained four relay of every group relay group are controlled three-phase output and center line four road signals respectively; Two corresponding in the signal of every road relay series connection are provided with, and said each relay adopts one and independently controls like the described photovoltaic suspension of claim 1-5 relay zero-crossing control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203704075U CN202268709U (en) | 2011-09-30 | 2011-09-30 | Photovoltaic broken network relay zero crossing control circuit and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203704075U CN202268709U (en) | 2011-09-30 | 2011-09-30 | Photovoltaic broken network relay zero crossing control circuit and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202268709U true CN202268709U (en) | 2012-06-06 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011203704075U Withdrawn - After Issue CN202268709U (en) | 2011-09-30 | 2011-09-30 | Photovoltaic broken network relay zero crossing control circuit and system |
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| CN (1) | CN202268709U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102510081A (en) * | 2011-09-30 | 2012-06-20 | 深圳市英威腾电气股份有限公司 | Zero-cross control circuit, method and system of photovoltaic network disconnection relay |
| CN109787290A (en) * | 2019-03-19 | 2019-05-21 | 矽力杰半导体技术(杭州)有限公司 | Photovoltaic system and its control circuit and control method |
-
2011
- 2011-09-30 CN CN2011203704075U patent/CN202268709U/en not_active Withdrawn - After Issue
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102510081A (en) * | 2011-09-30 | 2012-06-20 | 深圳市英威腾电气股份有限公司 | Zero-cross control circuit, method and system of photovoltaic network disconnection relay |
| CN109787290A (en) * | 2019-03-19 | 2019-05-21 | 矽力杰半导体技术(杭州)有限公司 | Photovoltaic system and its control circuit and control method |
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| AV01 | Patent right actively abandoned |
Granted publication date: 20120606 Effective date of abandoning: 20140618 |
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