CN211530760U - Coupling circuit and potential-induced attenuation preventing device comprising same - Google Patents
Coupling circuit and potential-induced attenuation preventing device comprising same Download PDFInfo
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- CN211530760U CN211530760U CN201921989664.XU CN201921989664U CN211530760U CN 211530760 U CN211530760 U CN 211530760U CN 201921989664 U CN201921989664 U CN 201921989664U CN 211530760 U CN211530760 U CN 211530760U
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
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Abstract
The utility model is suitable for a photovoltaic power generation field provides a coupling circuit and contains coupling circuit prevents the induced attenuator of electric potential, coupling circuit includes filtering energy storage unit, rectifier cell, reactance unit, wherein, filtering energy storage unit's input links to each other with power input end, coupling unit's output links to each other with rectifier cell's input, rectifier cell's output links to each other with reactance cell's input, reactance cell's output direct current voltage still provides one kind and contains coupling circuit prevents the induced attenuator of electric potential, the utility model discloses coupling circuit safety just can dynamically regulated, and adaptability well solves among the prior art photovoltaic cell board has high voltage to ground, can reduce photovoltaic cell's generating performance's technical problem.
Description
Technical Field
The utility model belongs to the photovoltaic power generation field especially relates to a coupling circuit and contain coupling circuit prevents the induced attenuator of electric potential.
Background
Potential Induced attenuation, abbreviated as pid (potential Induced attenuation), for the reasons: photovoltaic panels have a high voltage to ground, which can degrade the power generation performance of the photovoltaic cells. The positive and negative of the high voltage depend on the type of the photovoltaic cell panel, and the PID effect is generated when a P-type photovoltaic panel has a negative voltage to the ground or when an N-type photovoltaic panel has a positive voltage to the ground.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a coupling circuit and prevent induced attenuator of electric potential aims at solving among the prior art photovoltaic cell board and has high voltage to ground, can reduce photovoltaic cell's the technical problem of generating performance.
The utility model discloses a realize like this, a coupling circuit, including filtering energy storage unit, rectifier unit, reactance unit, wherein, filtering energy storage unit's input links to each other with the power input end, coupling unit's output links to each other with rectifier unit's input, rectifier unit's output links to each other with reactance unit's input, reactance unit's output direct current voltage.
The utility model discloses a further technical scheme is: the power supply is three-phase input, the coupling unit comprises three inductors, and each inductor is connected with one path of power supply input.
The utility model discloses a further technical scheme is: the rectifying unit comprises a three-phase bridge type passive rectifying unit or a three-phase bridge type active rectifying unit, and the output end of each inductor is connected with the middle point of a three-phase bridge arm of the rectifying unit.
The utility model discloses a further technical scheme is: the rectifier unit is a three-phase bridge type passive rectifier unit, an upper bridge arm and a lower bridge arm on the input side of the three-phase bridge type passive rectifier unit are composed of diodes, each bridge arm comprises two diodes connected in series, the output end of the inductor is connected between the two diodes connected in series, two ends of the diode connected in series are respectively connected with two ends of the reactance unit, the symmetrical midpoint of the reactance unit is a neutral point N, and two ends of the reactance unit are direct-current voltage positive and negative outputs.
The utility model discloses a further technical scheme is: when the rectifying unit is a three-phase bridge type passive rectifying unit, an upper bridge arm and a lower bridge arm on the input side of the three-phase bridge type passive rectifying unit are composed of semi-controlled rectifying devices, each bridge arm comprises two semi-controlled rectifying devices connected in series, wherein the output end of the inductor is connected between the two semi-controlled rectifying devices connected in series, and two ends of the semi-controlled rectifying devices connected in series are respectively connected with two ends of the reactance unit;
when the rectifying unit is a three-phase bridge type active rectifying unit, the upper and lower bridge arms at the input side of the three-phase bridge type active rectifying unit are composed of the same fully-controlled rectifying devices, each bridge arm comprises two fully-controlled rectifying devices connected in series, wherein the output end of the inductor is connected between the two fully-controlled rectifying devices connected in series, and two ends of the fully-controlled rectifying devices connected in series are respectively connected with two ends of the reactance unit.
The semi-controlled rectifier device can be a thyristor, and the fully-controlled rectifier device can be an IGBT (insulated gate bipolar transistor) tube or an MOS (metal oxide semiconductor) tube.
The utility model discloses a further technical scheme is: when the rectifying unit is a three-phase bridge active rectifying unit, the coupling circuit further comprises a filtering unit, and the filtering unit is arranged at the output end of the reactance unit
The utility model discloses a further technical scheme is: the filter unit is a filter bridge arm with the same structure as any one column of the three-phase bridge arm, wherein the input end of the filter bridge arm is connected with the symmetrical midpoint of the reactance unit through an inductor, the upper side and the lower side of the filter bridge arm are direct-current voltage positive and negative outputs, and the symmetrical midpoint of the bridge arm is a neutral point N.
The utility model discloses a further technical scheme is: the reactance unit is a resistor, a capacitor or a combination of the two.
The utility model discloses still provide one kind and contain coupling circuit prevents the induced attenuator of electric potential: the power supply comprises a communication module, an auxiliary power supply, a coupling circuit and an adjustable direct current source, wherein the input end of the coupling circuit is connected with a three-phase power line of a grid-connected inverter, the output end of the coupling circuit is electrically connected with the input end of the auxiliary power supply, the output end of the auxiliary power supply supplies power for the adjustable direct current source and the communication module, the positive output end of the adjustable direct current source is connected with a neutral point N of the coupling circuit, the negative output end of the adjustable direct current source is grounded PE (polyethylene) and used for adjusting the voltage of the neutral point N to the PE, and the communication module is in communication connection with the
The utility model discloses a further technical scheme is: the adjustable direct current source is an isolation DC/DC circuit, and the input end of the communication module is in communication connection with the grid-connected inverter in a wired or wireless mode.
The utility model has the advantages that: the compatibility is strong, the coupling circuit is safe and can be dynamically adjusted, the adaptability is good, the circuit is suitable for various uncontrollable, semi-controlled and fully-controlled rectifier components, the modular design is realized, and the manufacture and the maintenance are convenient; the device can be completely independent of a photovoltaic power generation system, has small volume and weight and low standby power consumption, and can work only when the triggering condition is met; the system has a safety protection function, and reports the fault of the photovoltaic power generation system after the voltage regulation range exceeds the threshold value of the upper limit interval and the lower limit interval; the photovoltaic grid-connected power generation system is compatible with a photovoltaic grid-connected power generation system formed by P-type and N-type photovoltaic components; compatible with wired and wireless signal transmission.
Drawings
FIG. 1 is a photovoltaic power generation system for preventing potential induced degradation provided by an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of an electromotive force preventing induced damping device according to an embodiment of the present invention;
fig. 3 is a block diagram of a coupling circuit according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a three-phase bridge type passive rectification coupling circuit composed of uncontrollable devices;
FIG. 5 is a schematic diagram of a three-phase bridge type passive rectification coupling circuit composed of semi-controlled devices;
FIG. 6 is a schematic diagram of a three-phase bridge type active rectifying coupling circuit composed of fully-controlled devices;
FIG. 7 is a schematic diagram of a three-phase bridge active rectifying coupling circuit with output filtering function;
fig. 8 is a basic circuit topology diagram inside the auxiliary power supply and the adjustable dc power supply.
Detailed Description
Fig. 1 shows that the utility model provides an it prevents induced attenuator of electric potential (prevent PID device for short), be applied to and have isolation transformer's photovoltaic power generation system between the electric wire netting for change grid-connected inverter three-phase and exchange the voltage of output side midpoint to ground, this system installs as independent unit, can effectively restrain photovoltaic module's the induced attenuation effect of electric potential.
As shown in fig. 1, the photovoltaic power generation system has the following structure: the output end of the photovoltaic module # M is connected with the input end of the grid-connected inverter # M, wherein M is any number from 1 to X (X is more than or equal to 2), the alternating current output end of the grid-connected inverter is connected with the low-voltage side of the isolation transformer, and the high-voltage side of the isolation transformer is connected with a power grid.
As shown in fig. 2, the potential-induction-proof attenuation apparatus of this example includes: the device comprises a communication module, a high-frequency auxiliary power supply (DC/DC), a coupling circuit and an adjustable direct current source (DC/DC). The input side of the high-frequency auxiliary power supply is connected with the positive output side and the negative output side of the coupling circuit, and the output end of the high-frequency auxiliary power supply is connected with the adjustable direct current source and the communication module to supply power for the two units. The input end of the coupling circuit is connected with a three-phase power line on the side of the isolation transformer inverter, and the output end of the coupling circuit is a neutral point N and a positive pole and a negative pole of direct-current voltage. The communication module is communicated with all inverters in a wired or wireless mode, and meanwhile, the output end of the communication module is connected with the adjustable direct current source control end to control the adjustable direct current source control end to be opened and closed; the input end of the adjustable direct current source is connected with the high-frequency auxiliary power supply, the positive pole of the output end is connected with the neutral point N output by the coupling circuit, and the negative pole of the output end is connected with the ground PE.
The communication module acquires the number and the working state of the inverters in the system in real time, ensures that all the inverters are started, and starts the adjustable direct current source to work after entering a grid-connected power generation state. And if any inverter in the system fails to complete the starting due to various reasons, the communication module controls the adjustable direct current source to be closed.
The adjustable direct current source adjusts the voltage from the neutral point N to the PE within a certain range, and when the voltage reaches the upper limit and the lower limit of the range, if the voltage of PV-to-PE can not meet the requirement, the fault of the photovoltaic power generation system is reported.
The communication module controls the adjustable direct current power supply to be started if and only if all the inverters work in a grid-connected power generation state, and one of the following two conditions is met: (1) for a photovoltaic module consisting of a P-type photovoltaic cell panel, if and only if the PV-to-PE voltage is less than 0; (2) for a photovoltaic module consisting of an N-type photovoltaic panel, if and only if the PV-to-PE voltage is greater than 0.
As shown in fig. 3, the coupling circuit of this embodiment includes a filtering energy storage unit, a rectifying unit, and a reactance unit, where an input end of the filtering energy storage unit is connected to a power input end, an output end of the coupling unit is connected to an input end of the rectifying unit, an output end of the rectifying unit is connected to an input end of the reactance unit, and an output end of the reactance unit outputs a dc voltage.
In the photovoltaic grid-connected power generation system, the grid-connected inverter outputs three-phase power. Therefore, the power input of this example is a three-phase input connected to A, B, C points of three-phase power respectively, and the coupling unit comprises three inductors, and each inductor is connected to one power input respectively.
The coupling circuit of the embodiment has three forms, specifically, three-phase bridge type passive rectification, three-phase bridge type active rectification and three-phase bridge type active rectification with an output filtering function. The three-phase input end is connected to the middle points of the three bridge arms through an inductor, and the reactance of the output end can be a resistor, a capacitor or a combination of the resistor and the capacitor. The output direct current voltage supplies power for the auxiliary power supply.
As shown in fig. 4, in the three-phase bridge passive rectification coupling circuit of this embodiment, the upper and lower bridge arms on the input side are formed by uncontrollable rectifier devices, such as diodes, the symmetric midpoint of the output reactance is a neutral point N, and the two ends of the output reactance unit are positive and negative output ends of the dc voltage.
As shown in fig. 5, in the three-phase bridge passive rectification coupling circuit of this embodiment, the upper and lower bridge arms on the input side are composed of half-controlled rectifier thyristors, the symmetric midpoint of the output reactance is a neutral point N, and the two ends of the output reactance are positive and negative outputs of a direct-current voltage. Other semi-controlled rectifier devices are also possible.
As shown in fig. 6, in the three-phase bridge active rectification coupling circuit of this embodiment, the upper and lower bridge arms on the input side are composed of fully-controlled rectifier devices, the symmetric midpoint of the output reactance is a neutral point N, and the two ends of the output reactance are positive and negative outputs of the dc voltage. The fully-controlled rectifier device of this example may employ an IGBT or MOS transistor.
As shown in fig. 7, the three-phase bridge active rectification coupling circuit of this embodiment may further have a filtering function by adding a filtering unit, where the filtering unit of this embodiment is a row of filtering bridge arms added at the rear end of the output reactance unit, the upper and lower ends of all the bridge arms of the coupling circuit are composed of IGBTs or MOS, the symmetric midpoint of the output filtering bridge arm is a neutral point N, and the upper and lower sides of the bridge arm are positive and negative outputs of the dc voltage.
As shown in fig. 8, the auxiliary power supply of this example is a high-frequency power supply output, and the adjustable DC source is an isolated DC/DC circuit structure for adjusting the voltages of N pairs of PEs. The communication module receives the PV-to-PE sampling information, and the communication mode can be a wired mode or a wireless mode.
The utility model discloses a theory of operation does:
in a photovoltaic power generation system formed by a P-type photovoltaic assembly, after all grid-connected inverters work normally, if the voltage of PV-pair PE is greater than or equal to 0, an adjustable direct current source module in a PID device is prevented from not working. At this time, the auxiliary power supply only provides the working power of the communication module. If the voltage of the PV-pair PE is negative, the auxiliary power supply provides working power of the communication module and the adjustable direct current source, and the adjustable direct current source adjusts and outputs direct current voltage according to the fed-back sampling information until the voltage of the PV-pair PE of all the grid-connected inverters which normally work is greater than or equal to 0. And if the output of the direct current source exceeds the upper limit of the interval, reporting a fault.
Present scheme of contrast the utility model has the advantages of it is following:
(1) the PID prevention device is completely independent of the photovoltaic power generation system, adopts high-frequency control and is small in size and weight;
(2) the PID prevention device is low in standby power consumption and can work only when the trigger condition is met;
(3) the PID prevention device has a safety protection function, and reports a system fault after the voltage regulation range exceeds the upper limit interval threshold and the lower limit interval threshold;
(4) the PID prevention device is compatible with a photovoltaic grid-connected power generation system formed by P-type and N-type photovoltaic modules;
(5) the PID prevention device is compatible with wired and wireless signal transmission;
(6) the PID prevention device is convenient to manufacture and maintain due to the fact that the internal structure of the PID prevention device is in a modular design.
The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. A coupling circuit, characterized by: the power supply comprises a filtering energy storage unit, a rectifying unit and a reactance unit, wherein the input end of the filtering energy storage unit is connected with the power input end, the output end of the filtering energy storage unit is connected with the input end of the rectifying unit, the output end of the rectifying unit is connected with the input end of the reactance unit, and the output end of the reactance unit outputs direct-current voltage.
2. The coupling circuit of claim 1, wherein: the power is three-phase input, the filtering energy storage unit comprises three inductors, and each inductor is connected with one path of power input respectively.
3. The coupling circuit of claim 2, wherein: the rectifying unit comprises a three-phase bridge type passive rectifying unit or a three-phase bridge type active rectifying unit, and the output end of each inductor is connected with the middle point of a three-phase bridge arm of the rectifying unit.
4. The coupling circuit of claim 3, wherein: the rectifier unit is a three-phase bridge type passive rectifier unit, an upper bridge arm and a lower bridge arm on the input side of the three-phase bridge type passive rectifier unit are composed of diodes, each bridge arm comprises two diodes connected in series, the output end of the inductor is connected between the two diodes connected in series, two ends of the diode connected in series are respectively connected with two ends of the reactance unit, the symmetrical midpoint of the reactance unit is a neutral point N, and two ends of the reactance unit are direct-current voltage positive and negative outputs.
5. The coupling circuit of claim 3, wherein: when the rectifying unit is a three-phase bridge type passive rectifying unit, an upper bridge arm and a lower bridge arm on the input side of the three-phase bridge type passive rectifying unit are composed of semi-controlled rectifying devices, each bridge arm comprises two semi-controlled rectifying devices connected in series, wherein the output end of the inductor is connected between the two semi-controlled rectifying devices connected in series, and two ends of the semi-controlled rectifying devices connected in series are respectively connected with two ends of the reactance unit;
when the rectifying unit is a three-phase bridge type active rectifying unit, the upper and lower bridge arms at the input side of the three-phase bridge type active rectifying unit are composed of the same fully-controlled rectifying devices, each bridge arm comprises two fully-controlled rectifying devices connected in series, wherein the output end of the inductor is connected between the two fully-controlled rectifying devices connected in series, and two ends of the fully-controlled rectifying devices connected in series are respectively connected with two ends of the reactance unit.
6. The coupling circuit of claim 5, wherein: when the rectifying unit is a three-phase bridge active rectifying unit, the coupling circuit further comprises a filtering unit, and the filtering unit is arranged at the output end of the reactance unit.
7. The coupling circuit of claim 6, wherein: the filter unit is a filter bridge arm with the same structure as any one column of the three-phase bridge arm, wherein the input end of the filter bridge arm is connected with the symmetrical midpoint of the reactance unit through an inductor, the upper side and the lower side of the filter bridge arm are direct-current voltage positive and negative outputs, and the symmetrical midpoint of the bridge arm is a neutral point N.
8. The coupling circuit according to any of claims 1-7, wherein: the reactance unit is a resistor, a capacitor or a combination of the two.
9. A potential-induced attenuation prevention apparatus comprising the coupling circuit of any one of claims 1-8, characterized in that: the power supply comprises a communication module, an auxiliary power supply, a coupling circuit and an adjustable direct current source, wherein the input end of the coupling circuit is connected with a three-phase power line of a grid-connected inverter, the output end of the coupling circuit is electrically connected with the input end of the auxiliary power supply, the output end of the auxiliary power supply supplies power for the adjustable direct current source and the communication module, the positive output end of the adjustable direct current source is connected with a neutral point N of the coupling circuit, the negative output end of the adjustable direct current source is grounded PE (polyethylene) and used for adjusting the voltage of the neutral point N to the PE, and the communication module is in communication connection with a control.
10. The potential-induced attenuation prevention device of claim 9, wherein: the adjustable direct current source is an isolation DC/DC circuit, and the input end of the communication module is in communication connection with the grid-connected inverter in a wired or wireless mode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921989664.XU CN211530760U (en) | 2019-11-18 | 2019-11-18 | Coupling circuit and potential-induced attenuation preventing device comprising same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921989664.XU CN211530760U (en) | 2019-11-18 | 2019-11-18 | Coupling circuit and potential-induced attenuation preventing device comprising same |
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| Publication Number | Publication Date |
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| CN211530760U true CN211530760U (en) | 2020-09-18 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201921989664.XU Active CN211530760U (en) | 2019-11-18 | 2019-11-18 | Coupling circuit and potential-induced attenuation preventing device comprising same |
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| CN (1) | CN211530760U (en) |
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Effective date of registration: 20221111 Address after: Floor 9, Keshida Industrial Park R&D Building, No.7 Road, Gaoxinyuan West District, Guangming New District, Shenzhen, Guangdong 518000 Patentee after: SHENZHEN KSTAR NEW ENERGY Co.,Ltd. Address before: 518000 rooms 401 and 402, 4th floor, building 1, software park, kejizhong 2nd Road, Gaoxin North District, Nanshan District, Shenzhen City, Guangdong Province (office only) Patentee before: SHENZHEN KSTAR SCIENCE AND TECHNOLOGY Co.,Ltd. Patentee before: SHENZHEN KSTAR NEW ENERGY Co.,Ltd. |