CN116722815A - PID effect suppression system, control method thereof and photovoltaic system - Google Patents
PID effect suppression system, control method thereof and photovoltaic system Download PDFInfo
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- CN116722815A CN116722815A CN202310987613.8A CN202310987613A CN116722815A CN 116722815 A CN116722815 A CN 116722815A CN 202310987613 A CN202310987613 A CN 202310987613A CN 116722815 A CN116722815 A CN 116722815A
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- 230000000694 effects Effects 0.000 title claims abstract description 71
- 230000001629 suppression Effects 0.000 title claims abstract description 52
- 238000000034 method Methods 0.000 title claims abstract description 28
- 230000001276 controlling effect Effects 0.000 claims description 17
- 238000004590 computer program Methods 0.000 claims description 6
- 230000001105 regulatory effect Effects 0.000 claims description 6
- 230000011664 signaling Effects 0.000 claims description 3
- 238000010248 power generation Methods 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 9
- 230000005764 inhibitory process Effects 0.000 description 8
- 206010014357 Electric shock Diseases 0.000 description 5
- 238000011217 control strategy Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
- H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
- H02S40/30—Electrical components
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/22—The renewable source being solar energy
- H02J2300/24—The renewable source being solar energy of photovoltaic origin
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
- Control Of Electrical Variables (AREA)
- Direct Current Feeding And Distribution (AREA)
Abstract
The invention provides a PID effect suppression system, a control method thereof and a photovoltaic system, and relates to the technical field of photovoltaic power generation. The PID effect suppression system comprises a power supply, a protection resistor and a switching device, wherein the output end of the power supply is used for being connected with the negative of a direct current bus of a photovoltaic system, one end of the protection resistor is connected with the other output end of the power supply, one end of the switching device is connected with the other end of the protection resistor, the other end of the switching device is connected with the ground, and when the switching device is closed, the PID effect suppression system is grounded to raise the negative voltage of the bus to the ground. The invention can make the PID effect suppression system grounded by closing the switch device when necessary, and promote the negative voltage to the ground of the bus, thereby effectively suppressing the PID effect, and has simple structure and easy implementation.
Description
Technical Field
The invention relates to the technical field of photovoltaic power generation, in particular to a PID effect suppression system, a control method thereof and a photovoltaic system.
Background
When the photovoltaic battery assembly works for a long time under negative bias, PID (Potential Induced Degradation) effect is very easy to generate, namely potential induced attenuation phenomenon, PID effect can cause great reduction of assembly power, the power generation capacity of the photovoltaic system is seriously influenced, and the actual power generation capacity of the photovoltaic power station is directly influenced, so that the PID effect needs to be restrained when the photovoltaic system works.
The existing PID effect suppression mode is mostly realized by changing the voltage to ground of the negative electrode of the photovoltaic panel or improving the voltage to ground of the front-stage battery panel of the inverter, for example, a power supply is arranged between a photovoltaic cell and the ground to compensate the voltage to ground of the negative electrode of the photovoltaic panel, or a voltage lifting circuit is used for lifting the voltage to ground of a neutral point on the alternating current side, so that the voltage to ground of the front-stage battery panel of the inverter is improved. However, the existing method generally has the problems of complex circuit and difficult implementation, and needs a complex structure to realize effective PID effect inhibition, and has potential safety hazards of electric shock, which is not beneficial to the development of PID effect inhibition work.
Disclosure of Invention
The invention solves the problem of how to realize safe and effective PID effect inhibition.
In order to solve the problems, the invention provides a PID effect suppression system, a control method thereof and a photovoltaic system.
In a first aspect, the present invention provides a PID effect suppression system, including a power supply, a protection resistor, and a switching device, where an output end of the power supply is connected to a midpoint of a bus of a photovoltaic system, one end of the protection resistor is connected to an input end of the power supply, one end of the switching device is connected to the other end of the protection resistor, and the other end of the switching device is connected to ground, and when the switching device is closed, the PID effect suppression system is grounded to raise a negative voltage to ground of the bus;
wherein the protection resistor is used for reducing the current flowing through a human body when the PV is in a positive/negative ground short circuit;
the power supply is used for lifting the negative voltage to ground of the bus to above zero when the PID effect suppression system is grounded so as to suppress PID effect;
the switching device is used for controlling the opening and closing through the state of the controller or the grid-connected contactor.
Optionally, the PID effect suppression system further comprises a fuse device, the fuse device being arranged between the protection resistor and the switching device, the fuse device being configured to open when the current exceeds a preset current value.
In a second aspect, the present invention provides a control method of a PID effect suppression system, applied to the PID effect suppression system, including:
determining the minimum value of the protection resistor according to the limiting value of the human body current;
controlling the switching device to be closed so as to enable the PID effect suppression system to be grounded;
the supply voltage is regulated to raise the bus negative ground voltage above zero.
Optionally, the controlling the switch device to close includes:
the switching device is closed by a controller.
Optionally, the controlling the switch device to close includes:
when the grid-connected contactor of the system is closed, feeding back a high-level signal, and controlling the switching device to be closed;
when at night, the switch device is controlled to be closed.
Optionally, the control method of the PID effect suppression system further includes:
when the grid-connected contactor of the system is disconnected, a low-level signal is fed back, and the switching device is controlled to be disconnected;
and when the bus voltage is greater than the lower threshold, controlling the switching device to be switched off.
Optionally, the determining the minimum value of the protection resistance according to the human body current limit value includes: determining the current flowing through the human body, and determining the minimum value of the protection resistor according to the current flowing through the human body and the human body current limit value;
wherein, when the PV is shorted to ground, the current flowing through the human body is expressed as:
when the DC/DC circuit employs a Boost circuit:
；
when the DC/DC circuit employs a three-level Boost circuit:
；
wherein, when the PV is shorted to ground, the current flowing through the human body is expressed as:
when the DC/DC circuit employs a Boost circuit:
；
when the DC/DC circuit employs a three-level Boost circuit:
；
wherein I is person Representing the current flowing through the human body, V PV Representing the photovoltaic voltage, V dc Represents bus voltage, V PID Represents PID power supply voltage, R PID Representing the protection resistance, R person Representing the resistance of the human body.
Optionally, the adjusting the power supply voltage to raise the bus negative ground voltage above zero comprises:
acquiring the negative voltage to ground of the bus;
and regulating the power supply voltage according to the bus negative ground voltage so as to lift the bus negative ground voltage to be above zero.
Optionally, said adjusting said supply voltage according to said bus negative ground voltage comprises:
determining a comparison value according to the bus negative ground voltage and an instruction value, wherein the instruction value is greater than zero;
inputting the comparison value into a voltage loop and a current loop to generate a duty cycle signal to regulate the power supply voltage.
In a third aspect, the present invention provides a photovoltaic system comprising the above PID effect suppression system, or comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing a control method of the above PID effect suppression system when executing the computer program.
The invention sets the PID effect inhibition system composed of the power supply, the protection resistor and the switch device, the power supply generates voltage to raise the bus negative earth voltage, for example, the bus negative earth voltage is raised to above zero to inhibit the PID effect, the protection resistor limits the current in the loop, the current flowing through the human body can be reduced when the PV is in positive/negative earth short circuit, the risk of electric shock of the human body is prevented, the switch device controls whether the PID effect inhibition system is connected with the photovoltaic system, the switch device is closed (for example, the switch is controlled to be opened or closed by the state of the controller or the grid-connected contactor) when necessary, the PID effect inhibition system is grounded, the bus negative earth voltage is raised, the PID effect is effectively inhibited, and the safety of the PID effect inhibition when the PID effect is carried out is ensured.
Drawings
FIG. 1 is a schematic diagram of a PID effect suppression system according to an embodiment of the invention;
FIG. 2 is a schematic diagram of a PID effect suppression system and a photovoltaic system according to an embodiment of the invention;
FIG. 3 is a schematic diagram of a DC/DC topology using Boost circuitry according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a DC/DC topology using a three-level Boost circuit according to an embodiment of the present invention;
FIG. 5 is an equivalent circuit of a PV being shorted to ground when DC/DC is a Boost circuit in accordance with an embodiment of the present invention;
FIG. 6 is an equivalent circuit of a negative PV-to-ground short circuit when DC/DC is a Boost circuit in accordance with an embodiment of the present invention;
FIG. 7 is an equivalent circuit of a PV shorted to ground when DC/DC is a three-level Boost circuit in accordance with an embodiment of the present invention;
FIG. 8 is an equivalent circuit of a negative PV-shorted to ground when the DC/DC is a three-level Boost circuit in accordance with an embodiment of the present invention;
FIG. 9 is a power scheme for grid-side power extraction in accordance with an embodiment of the present invention;
FIG. 10 is a power scheme for bus side-draw in accordance with an embodiment of the present invention;
FIG. 11 is an equivalent circuit diagram of FIG. 3;
FIG. 12 is an equivalent circuit diagram of FIG. 11;
FIG. 13 is a schematic diagram of a power supply voltage control strategy according to an embodiment of the present invention;
FIG. 14 is a schematic diagram of a switching device according to an embodiment of the present invention;
fig. 15 is a second control schematic diagram of the switching device according to the embodiment of the invention.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
As shown in fig. 1, an embodiment of the present invention provides a PID effect suppression system, including a power supply, a protection resistor and a switching device, where an output end of the power supply is used to be connected to a negative dc bus of a photovoltaic system, one end of the protection resistor is connected to another output end of the power supply, one end of the switching device is connected to another end of the protection resistor, another end of the switching device is connected to ground, and when the switching device is closed, the PID effect suppression system is grounded to raise a negative voltage to ground of the bus;
wherein the protection resistor is used for reducing the current flowing through a human body when the PV is in a positive/negative ground short circuit;
the power supply is used for lifting the negative voltage to ground of the bus to above zero when the PID effect suppression system is grounded so as to suppress PID effect;
the switching device is used for controlling the opening and closing through the state of the controller or the grid-connected contactor.
Specifically, as shown in connection with FIG. 2, a PID effect suppression system (referred to as PID apparatus in FIG. 2) is connected between the bus bar negative and ground, including a power supply V PID Protection resistor R PID And a switch device S PID (e.g., relay, etc.), power supply V PID Protection resistor R PID And a switch device S PID Sequentially connected with a power supply V PID For generating voltage to raise bus negative voltage to ground, protection resistor R PID For limiting the current in the circuit, preventing the risk of electric shock to the person, switching device S PID And the PID effect suppression system is used for controlling whether the PID effect suppression system is connected into the photovoltaic system or not.
Since the potential at the midpoint of the bus bar of the photovoltaic system should theoretically be half the output voltage of the photovoltaic panel set when the photovoltaic system is operating normally. As the photovoltaic system continuously works, the photovoltaic system is subjected to PID effect, so that the busbar voltage of the photovoltaic system is attenuated; at the moment, the potential of the middle point of a bus of the photovoltaic system can be kept at more than half of the output voltage of the photovoltaic panel set through the PID effect suppression system, so that the negative electrode of the photovoltaic panel set can be lifted to the ground potential, and the PID effect is suppressed.
In the photovoltaic system, the circuit topologies of the DC/DC and the DC/AC can be conventional topologies, for example, the DC/DC shown in fig. 3 adopts a Boost circuit, or the DC/DC shown in fig. 4 adopts a three-level Boost circuit, and the DC/AC adopts an NPC three-level structure.
Optionally, the PID effect suppression system further comprises a fuse device, the fuse device being arranged between the protection resistor and the switching device, the fuse device being configured to open when the current exceeds a preset current value.
Specifically, as shown in connection with fig. 2, the PID effect suppression system further includes a fuse device F PID (e.g. fuse, etc.), fusing device F PID The protection function is achieved, the circuit can be disconnected when the current exceeds a preset current value, and the damage of long-time large current to the circuit is prevented.
Another embodiment of the present invention provides a control method of a PID effect suppression system, which is applied to the PID effect suppression system, including:
determining the minimum value of the protection resistor according to the limiting value of the human body current;
controlling the switching device to be closed so as to enable the PID effect suppression system to be grounded;
the supply voltage is regulated to raise the bus negative ground voltage above zero.
Optionally, the determining the minimum value of the protection resistance according to the human body current limit value includes: and determining the current flowing through the human body, and determining the minimum value of the protection resistor according to the current flowing through the human body and the human body current limit value.
Specifically, the resistance R PID Is selected according to the safety of preventing the person from getting an electric shock. The worst case is when the PV is being shorted to ground, while the enclosure is not isolated from ground. If a person touches the casing, the equivalent circuit is that shown in fig. 5, the DC/DC circuit adopts a Boost circuit, and the PV negative and the Bus negative are directly connected.
According to fig. 5, the current flowing through the human body is approximately formula (1), noting the human body resistance R person <<R PID 。
（1）；
Assuming that the current flowing through the human body needs to be less than 10mA, the photovoltaic voltage V PV =1300v, pid supply voltage V PID The voltage is 700V, and the resistance R can be calculated PID >200kΩ。
The same can be said to be the case when the PV negative is shorted to ground, while the enclosure is not isolated from ground. If a person touches the housing, the equivalent circuit at this time is as shown in FIG. 6.
According to fig. 6, the current flowing through the human body is approximately:
（2）；
assuming that the current flowing through the human body needs to be less than 10mA, the PID power supply voltage V PID The voltage is 700V, and the resistance R can be calculated PID >70kΩ。
From the above analysis, the most badInferior condition is that PV is short-circuited to ground, R PID The resistor can be selected according to the formula (1), and the resistor can effectively prevent the danger of electric shock of people.
Assuming that the DC/DC circuit is considered to be a three-level Boost circuit, having a diode between the PV negative and the Bus negative corresponds to a voltage source between the PV negative and the Bus negative, the voltage is (V dc -V PV )/2. When a short circuit to ground is occurring at the PV, the equivalent circuit at this time is shown in fig. 7.
According to fig. 7, the current flowing through the human body is approximately formula (3).
（3）；
Assuming that the current flowing through the human body needs to be less than 10mA, the photovoltaic voltage V PV 1300V, busbar voltage V dc 1500V, pid supply voltage V PID The voltage is 700V, and the resistance R can be calculated PID >220kΩ. It follows that three levels of DC/DC have a higher requirement for resistance.
The equivalent circuit that can be obtained in the same way when the PV negative is shorted to ground is shown in fig. 8.
According to fig. 8, the current flowing through the human body is approximately:
（4）；
assuming that the current flowing through the human body needs to be less than 10mA, the photovoltaic voltage V PV 1300V, busbar voltage V dc 1500V, pid supply voltage V PID The voltage is 700V, and the resistance R can be calculated PID >80kΩ。
Optionally, the adjusting the power supply voltage to raise the bus negative ground voltage above zero comprises:
acquiring the negative voltage to ground of the bus;
and regulating the power supply voltage according to the bus negative ground voltage so as to lift the bus negative ground voltage to be above zero.
Specifically, the power supply V is first described PID The conventional isolation type circuit can be selected. Referring to FIG. 9, the web sideThe power is taken, the topological structure is AC/DC+isolated DC/DC, the AC/DC can adopt three-phase uncontrolled rectification, and the DC/DC adopts flyback DC/DC. And in combination with the illustration of fig. 10, the bus side is powered, the topological structure is an isolated DC/DC, and the DC/DC adopts an isolated phase-shifting full-bridge DC/DC.
Referring to FIG. 11, it is assumed that in the ideal case, V PV1 =V PV2 =…V PVn =V PV ，R PV1+ =…=R PVn+ = R PV1- =…=R PVn- =R PV The circuit of FIG. 11 can be further equivalent to FIG. 12, and according to FIG. 12, the voltage V of the PV negative to ground can be obtained N_PE As in formula (5).
（5）；
Let it be assumed that the photovoltaic voltage V PV =1300v, pid resistor R PID 510KΩ, photovoltaic ground resistance R PV 8mΩ, n=15 photovoltaic strings, V when PV is negative to ground N_PE >0, can calculate PID voltage V PID >1320V。
Similarly, three-level DC/DC analysis may be performed, and will not be described in detail herein.
Optionally, said adjusting said supply voltage according to said bus negative ground voltage comprises:
determining a comparison value according to the bus negative ground voltage and an instruction value, wherein the instruction value is greater than zero;
inputting the comparison value into a voltage loop and a current loop to generate a duty cycle signal to regulate the power supply voltage.
Specifically, as shown in connection with FIG. 13, the voltage V PID The closed-loop control strategy can be adopted, and the negative voltage V of the bus to the ground is detected firstly N_PE Then with the command value V N_PE* Comparing, wherein the command value V N_PE* Should be a value greater than zero so that daytime PID effect suppression is achieved. The comparison value generates a duty ratio signal through a voltage loop and a current loop, and then controls the PID power supply voltage V PID 。
Optionally, the controlling the switch device to close includes:
the switching device is closed by a controller.
Specifically, the first control method of the switching device is: the control method is flexible, and the on and off time is flexibly configured.
The controlling of the switching device closure comprises:
when the grid-connected contactor of the system is closed, feeding back a high-level signal, and controlling the switching device to be closed;
when at night, the switch device is controlled to be closed.
Optionally, the control method of the PID effect suppression system further includes:
when the grid-connected contactor of the system is disconnected, a low-level signal is fed back, and the switching device is controlled to be disconnected;
and when the bus voltage is greater than the lower threshold, controlling the switching device to be switched off.
Specifically, the second control method of the switching device is a control method of pure hardware, and is controlled by outputting a feedback signal of the grid-connected contactor in combination with the control method shown in fig. 14. When the grid-connected contactor of the system is closed, the feedback signal is high level, and then the PID power relay S is controlled PID Closing. When the grid-connected contactor of the system is disconnected, the feedback signal is low level, and then the PID power relay S is controlled PID And (5) disconnecting.
Specifically, the third control method of the switching device is a control method of pure hardware, and in combination with the method shown in fig. 15, the daytime PID inhibition and the evening PID repair can be simultaneously realized. The control logic is performed by outputting feedback signals of grid-connected contactors and bus voltage feedback. After a grid-connected contactor of the system is closed in daytime, a high level of a feedback signal is fed back, and then a PID power relay S is controlled PID Closing. At night, the inverter does not work, the bus voltage is zero and is smaller than the lower threshold V limit The feedback signal is high level, and then the PID power relay S is controlled PID Closing. In other cases, such as before grid connection in daytime, the output contactor is not closed, and the bus voltage is greater than the lower threshold V limit Both feedback signals are low level, and then the PID power relay S is controlled PID And (5) disconnecting.
Another embodiment of the present invention provides a photovoltaic system, including the above PID effect suppression system, or including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the control method of the above PID effect suppression system when executing the computer program.
Although the invention is disclosed above, the scope of the invention is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications will fall within the scope of the invention.
Claims (10)
1. The PID effect suppression system is characterized by comprising a power supply, a protection resistor and a switching device, wherein the output end of the power supply is used for being connected with the negative of a direct current bus of a photovoltaic system, one end of the protection resistor is connected with the other output end of the power supply, one end of the switching device is connected with the other end of the protection resistor, the other end of the switching device is connected with the ground, and when the switching device is closed, the PID effect suppression system is grounded to raise the negative voltage of the bus to the ground;
wherein the protection resistor is used for reducing the current flowing through a human body when the PV is in a positive/negative ground short circuit;
the power supply is used for lifting the negative voltage to ground of the bus to above zero when the PID effect suppression system is grounded so as to suppress PID effect;
the switching device is used for controlling the opening and closing through the state of the controller or the grid-connected contactor.
2. The PID effect suppression system of claim 1, further comprising a fuse device disposed between the protection resistor and the switching device, the fuse device configured to open when the current exceeds a preset current value.
3. A control method of a PID effect suppression system, applied to the PID effect suppression system according to claim 1 or 2, characterized by comprising:
determining the minimum value of the protection resistor according to the limiting value of the human body current;
controlling the switching device to be closed so as to enable the PID effect suppression system to be grounded;
the supply voltage is regulated to raise the bus negative ground voltage above zero.
4. A control method of a PID effect suppression system according to claim 3, characterized in that the control of the switching means to close comprises:
the switching device is closed by a controller.
5. A control method of a PID effect suppression system according to claim 3, characterized in that the control of the switching means to close comprises:
when the grid-connected contactor of the system is closed, feeding back a high-level signal, and controlling the switching device to be closed;
when at night, the switch device is controlled to be closed.
6. A control method of a PID effect suppression system according to claim 3, further comprising:
when the grid-connected contactor of the system is disconnected, a low-level signal is fed back, and the switching device is controlled to be disconnected;
and when the bus voltage is greater than the lower threshold, controlling the switching device to be switched off.
7. A control method of a PID effect suppression system according to claim 3, characterized in that the determination of the minimum value of the protection resistance according to the human body current limit value comprises: determining the current flowing through the human body, and determining the minimum value of the protection resistor according to the current flowing through the human body and the human body current limit value;
wherein, when the PV is shorted to ground, the current flowing through the human body is expressed as:
when the DC/DC circuit employs a Boost circuit:
；
when the DC/DC circuit employs a three-level Boost circuit:
；
wherein, when the PV is shorted to ground, the current flowing through the human body is expressed as:
when the DC/DC circuit employs a Boost circuit:
；
when the DC/DC circuit employs a three-level Boost circuit:
；
wherein I is person Representing the current flowing through the human body, V PV Representing the photovoltaic voltage, V dc Represents bus voltage, V PID Represents PID power supply voltage, R PID Representing the protection resistance, R person Representing the resistance of the human body.
8. A control method of a PID effect suppression system according to claim 3, characterized in that the adjusting the supply voltage to raise the bus negative ground voltage above zero comprises:
acquiring the negative voltage to ground of the bus;
and regulating the power supply voltage according to the bus negative ground voltage so as to lift the bus negative ground voltage to be above zero.
9. The control method of the PID effect suppression system according to claim 8, characterized in that the adjusting the power supply voltage according to the bus negative-to-ground voltage includes:
determining a comparison value according to the bus negative ground voltage and an instruction value, wherein the instruction value is greater than zero;
inputting the comparison value into a voltage loop and a current loop to generate a duty cycle signal to regulate the power supply voltage.
10. A photovoltaic system comprising the PID effect suppression system of claim 1 or 2, or comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the control method of the PID effect suppression system of any of claims 3 to 9 when executing the computer program.
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| CN104300584A (en) * | 2014-11-07 | 2015-01-21 | 深圳市永联科技有限公司 | High-security PID effect inhibition method |
| CN104617873A (en) * | 2015-02-02 | 2015-05-13 | 北京格林科电技术有限公司 | Method and device for suppressing potential induced degradation (PID) phenomenon of photovoltaic module through inverter |
| CN107069661A (en) * | 2017-04-28 | 2017-08-18 | 南京南瑞太阳能科技有限公司 | A kind of device for suppressing photovoltaic module PID effects |
| US20220334159A1 (en) * | 2020-03-11 | 2022-10-20 | Fronius International Gmbh | Method and photovoltaic inverter for determining the system capacity of a photovoltaic system to ground |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104300584A (en) * | 2014-11-07 | 2015-01-21 | 深圳市永联科技有限公司 | High-security PID effect inhibition method |
| CN104617873A (en) * | 2015-02-02 | 2015-05-13 | 北京格林科电技术有限公司 | Method and device for suppressing potential induced degradation (PID) phenomenon of photovoltaic module through inverter |
| CN107069661A (en) * | 2017-04-28 | 2017-08-18 | 南京南瑞太阳能科技有限公司 | A kind of device for suppressing photovoltaic module PID effects |
| US20220334159A1 (en) * | 2020-03-11 | 2022-10-20 | Fronius International Gmbh | Method and photovoltaic inverter for determining the system capacity of a photovoltaic system to ground |
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