CN117996850A - Inverter grid connection method and device and photovoltaic system - Google Patents
Inverter grid connection method and device and photovoltaic system Download PDFInfo
- Publication number
- CN117996850A CN117996850A CN202410117528.0A CN202410117528A CN117996850A CN 117996850 A CN117996850 A CN 117996850A CN 202410117528 A CN202410117528 A CN 202410117528A CN 117996850 A CN117996850 A CN 117996850A
- Authority
- CN
- China
- Prior art keywords
- grid
- relay
- inverter
- bus
- photovoltaic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 79
- 230000007935 neutral effect Effects 0.000 claims abstract description 69
- 238000004590 computer program Methods 0.000 claims description 14
- 238000004422 calculation algorithm Methods 0.000 abstract description 10
- 238000004364 calculation method Methods 0.000 abstract description 8
- 230000001276 controlling effect Effects 0.000 description 33
- 230000000694 effects Effects 0.000 description 16
- 230000008569 process Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 239000003990 capacitor Substances 0.000 description 6
- 238000004891 communication Methods 0.000 description 6
- 230000002401 inhibitory effect Effects 0.000 description 5
- 238000001514 detection method Methods 0.000 description 4
- 238000001914 filtration Methods 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 238000013459 approach Methods 0.000 description 2
- 230000003190 augmentative effect Effects 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 101100004933 Arabidopsis thaliana CYP79F1 gene Proteins 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 239000003415 peat Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Landscapes
- Inverter Devices (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The application discloses an inverter grid-connected method and device and a photovoltaic system, and belongs to the technical field of electric power. The inverter grid-connected method is applied to a photovoltaic system comprising a PID power supply, and comprises the following steps: before grid connection of a photovoltaic inverter in a photovoltaic system, controlling output of a PID power supply to adjust a difference value between a potential of a neutral point of a direct current bus of the photovoltaic inverter and zero to be not more than a first threshold value; and controlling a grid-connected relay in the photovoltaic system to be closed. According to the inverter grid-connection method and device and the photovoltaic system, grid-connection impact current is restrained by controlling the neutral point to ground voltage of the direct current bus by using the PID power supply in the photovoltaic system, the photovoltaic system is connected with the grid under the condition that the neutral point to ground voltage of the direct current bus is about zero, no additional hardware circuit and complex calculation and control algorithm are required to be added, no impact current during grid-connection can be strictly realized, and grid-connection impact current can be restrained more effectively and at lower cost.
Description
Technical Field
The application belongs to the technical field of electric power, and particularly relates to an inverter grid-connected method and device and a photovoltaic system.
Background
Before the grid connection of the photovoltaic system is connected to a large power grid, the output voltage of the inverter circuit is inconsistent with the voltage of the large power grid in amplitude, frequency, phase and the like, so that a large voltage difference exists when the grid connection switch is closed, the grid connection impact current is overlarge, output inductance saturation, misoperation of a protection device and the like are easily caused, and huge damage is generated to the whole photovoltaic system.
In order to suppress the impact current in the grid connection, three methods are mainly adopted at present: zero crossing detection, phase-locked loop and built-in resistance. However, all of the above three methods have the disadvantage that it is difficult to effectively suppress the grid-connected rush current at low cost.
Disclosure of Invention
The present application aims to solve at least one of the technical problems existing in the prior art. Therefore, the application provides an inverter grid-connected method and device and a photovoltaic system, which can effectively and low-cost inhibit grid-connected impact current.
In a first aspect, the present application provides an inverter grid-tie method applied to a photovoltaic system including a PID power source, the method comprising:
Before grid connection of a photovoltaic inverter in the photovoltaic system, controlling output of the PID power supply to adjust a difference value between a potential of a neutral point of a direct current bus of the photovoltaic inverter and zero to be not more than a first threshold value;
And controlling a grid-connected relay in the photovoltaic system to be closed.
According to the grid-connected method of the inverter, the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is controlled by utilizing the PID power supply in the photovoltaic system to inhibit the N-line impact current during grid connection, and the photovoltaic system is connected only when the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is about zero.
According to one embodiment of the present application, the controlling the output of the PID power supply to adjust the difference between the potential of the neutral point of the dc bus of the photovoltaic inverter and zero to not exceed a first threshold value before the photovoltaic inverter in the photovoltaic system is connected to the grid includes:
And controlling the PID power supply to charge the positive electrode of the direct current bus so that the difference value between the voltage between the positive electrode of the direct current bus and the ground wire and half of the voltage of the direct current bus does not exceed a second threshold value.
According to the grid-connected method of the inverter, the positive electrode of the direct current bus is charged by controlling the PID power supply, so that the voltage between the positive electrode of the direct current bus and the ground wire is about half of the voltage of the direct current bus, the ground voltage of the neutral point of the direct current bus of the photovoltaic inverter is about zero, no additional hardware circuit and complicated calculation and control algorithm are required to be added, the ground voltage of the neutral point of the direct current bus of the photovoltaic inverter is zero, no impact current exists on the N lines of a grid during grid connection, and the grid-connected method is simpler, more reliable and safer, can be applied to all photovoltaic systems with the PID power supply, and can restrain grid-connected impact current more effectively and at lower cost.
According to one embodiment of the present application, the controlling the output of the PID power supply to adjust the difference between the potential of the neutral point of the dc bus of the photovoltaic inverter and zero to not exceed a first threshold value before the photovoltaic inverter in the photovoltaic system is connected to the grid includes:
And controlling the PID power supply to charge the negative electrode of the direct current bus so that the difference value between the voltage between the ground wire and the negative electrode of the direct current bus and half of the voltage of the direct current bus does not exceed a third threshold value.
According to the grid-connected method of the inverter, the negative electrode of the direct current bus is charged by controlling the PID power supply, so that the voltage between the ground wire and the negative electrode of the direct current bus is about half of the voltage of the direct current bus, the ground voltage of the neutral point of the direct current bus of the photovoltaic inverter is about zero, no additional hardware circuit and complicated calculation and control algorithm are required to be added, the ground voltage of the neutral point of the direct current bus of the photovoltaic inverter is zero, no impact current exists on the N line of the grid during grid connection, and the grid-connected method is simpler, more reliable and safer, can be applied to all photovoltaic systems containing the PID power supply, and can restrain grid-connected impact current more effectively and at lower cost.
According to one embodiment of the application, the PID power supply includes a first relay, a second relay, a third relay, and a fourth relay; the first relay is used for connecting the positive electrode of the direct current bus; the second relay is used for connecting the negative electrode of the direct current bus; the third relay is used for connecting a photovoltaic panel in the photovoltaic system; the fourth relay is used for being connected with the ground wire;
the control of the PID power supply to charge the anode of the direct current bus comprises the following steps:
and controlling the first relay and the fourth relay to be closed, and charging the anode of the direct current bus.
According to one embodiment of the application, the PID power supply includes a first relay, a second relay, a third relay, and a fourth relay; the first relay is used for connecting the positive electrode of the direct current bus; the second relay is used for connecting the negative electrode of the direct current bus; the third relay is used for connecting a photovoltaic panel in the photovoltaic system; the fourth relay is used for being connected with the ground wire;
The control of the PID power supply to charge the negative electrode of the direct current bus comprises the following steps:
and controlling the second relay and the fourth relay to be closed, and charging the negative electrode of the direct current bus.
In a second aspect, the present application provides an inverter grid-tie device for use in a photovoltaic system including a PID power source, the device comprising:
The first control module is used for controlling the output of the PID power supply before grid connection of the photovoltaic inverter in the photovoltaic system so as to adjust the difference value between the potential of the neutral point of the direct current bus of the photovoltaic inverter and zero to be not more than a first threshold value;
And the second control module is used for controlling the grid-connected relay in the photovoltaic system to be closed.
According to the inverter grid-connected device, the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is controlled by utilizing the PID power supply in the photovoltaic system to inhibit the N-line impact current during grid connection, and the photovoltaic system is connected only when the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is about zero.
In a third aspect, the present application provides a photovoltaic system comprising a photovoltaic panel, a boost circuit, a photovoltaic inverter, a grid-tie relay, a PID power source and an inverter grid-tie device as described in the second aspect.
In a fourth aspect, the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the inverter grid-tie method according to the first aspect when executing the computer program.
In a fifth aspect, the present application provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the inverter grid-tie method as described in the first aspect above.
In a sixth aspect, the present application provides a chip, where the chip includes a processor and a communication interface, where the communication interface is coupled to the processor, and the processor is configured to execute a program or instructions to implement the inverter grid-tie method according to the first aspect.
In a seventh aspect, the present application provides a computer program product comprising a computer program which, when executed by a processor, implements the inverter grid-tie method as described in the first aspect above.
Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.
Drawings
The foregoing and/or additional aspects and advantages of the application will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:
Fig. 1 is a schematic diagram of an application scenario of a built-in resistance method in the related art according to an embodiment of the present application;
fig. 2 is a schematic flow chart of an inverter grid-connected method according to an embodiment of the present application;
fig. 3 is a schematic diagram of an application scenario of an inverter grid-connected method provided by an embodiment of the present application;
fig. 4 is a schematic structural diagram of a PID power supply in an inverter grid-connected method according to an embodiment of the present application;
fig. 5 is a schematic structural diagram of an inverter grid-connected device according to an embodiment of the present application;
fig. 6 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
The technical solutions of the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which are obtained by a person skilled in the art based on the embodiments of the present application, fall within the scope of protection of the present application.
The terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged, as appropriate, such that embodiments of the present application may be implemented in sequences other than those illustrated or described herein, and that the objects identified by "first," "second," etc. are generally of a type, and are not limited to the number of objects, such as the first object may be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.
In the related art, a photovoltaic inverter is a core device of a photovoltaic system. The photovoltaic inverter not only can convert direct current generated by photovoltaic modules such as a photovoltaic panel into alternating current, but also needs to safely, stably and efficiently integrate the alternating current into a power grid.
In order to suppress the rush current generated when the photovoltaic inverter is connected to the grid, three solutions are mainly adopted at present.
The first is zero crossing detection. The zero crossing point detection method is used for controlling the closing of the relay through the zero crossing point detection result of the voltage phase of the power grid on the basis of estimating the closing response time of the grid-connected relay so as to inhibit grid-connected impact current. According to the method, the difficulty in estimating the closing response time of the grid-connected relay is high, the estimation result is influenced by factors such as aging and/or closing bounce of the relay, zero crossing fluctuation exists in the voltage of the relay power grid when the relay is closed, impact current still exists, and the effect of inhibiting the grid-connected impact current is poor.
The second is the phase-locked loop method. Before the grid-connected relay is closed, the photovoltaic inverter works in an off-grid mode, no current is output, voltages of an inversion side line and a power grid side line are collected, a target driving signal required by decoupling control of an inner loop of a power grid voltage feedforward current is obtained through a phase-locked loop algorithm, the amplitude, the phase and the frequency of the output voltage of the photovoltaic inverter are consistent with the power grid voltage, and finally the grid-connected relay is closed, so that the impact current is effectively inhibited. The switching process of the working mode of the photovoltaic inverter is complex, the switching time is difficult to accurately determine, the control algorithm is complex, more storage space is occupied, and the photovoltaic inverter works in the off-grid mode to generate additional energy loss.
The third is a built-in resistance method. As shown in fig. 1, the output side of the voltage-type photovoltaic inverter is connected in parallel with a built-in resistor R1 and then connected to a power grid. The parallel built-in resistor R1 will give the output of the photovoltaic inverter a feedback current that can be used for a given control of the current loop before the photovoltaic inverter is grid-connected. Therefore, when grid connection is performed, the given step change quantity of the current loop is reduced, and the phase difference between the output current of the photovoltaic inverter and the power supply phase of the power grid can be effectively reduced. In the method, the resistance value of the built-in resistor R1 is difficult to quantitatively calculate, the effect of inhibiting grid-connected impact current is poor due to inaccurate resistance value of the built-in resistor R1, and the built-in resistor R1 can cause loss of system energy and increase of cost.
Note that, in fig. 1, P and N represent the positive electrode and the negative electrode of the photovoltaic panel, respectively; the photovoltaic panel can be connected with the inverter through the boost circuit; the output end of the inverter can be connected with a filter circuit firstly and then connected with a built-in resistor R1 in parallel; the output side of the inverter can be connected with the power grid side through a switch K; r 2 represents grid-connected load at the grid side; u g denotes the grid.
Although the three methods can suppress grid-connected impact current to a certain extent, the three methods have the defect that the grid-connected impact current is difficult to effectively suppress at low cost. Therefore, how to effectively and inexpensively suppress grid-connected impact current of a photovoltaic inverter has become one of the technical difficulties to be solved in the art.
The inverter grid-connection method, the inverter grid-connection device, the electronic equipment and the readable storage medium provided by the embodiment of the application are described in detail below through specific embodiments and application scenes thereof with reference to the accompanying drawings.
The inverter grid-connected method can be applied to the terminal, and can be specifically executed by hardware or software in the terminal.
The terminal includes, but is not limited to, a portable communication device such as a mobile phone or tablet having a touch sensitive surface (e.g., a touch screen display and/or a touch pad). It should also be appreciated that in some embodiments, the terminal may not be a portable communication device, but rather a desktop computer having a touch-sensitive surface (e.g., a touch screen display and/or a touch pad).
In the following various embodiments, a terminal including a display and a touch sensitive surface is described. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, mouse, and joystick.
The implementation main body of the inverter grid-connected method provided by the embodiment of the application can be electronic equipment or a functional module or a functional entity capable of realizing the inverter grid-connected method in the electronic equipment, and the electronic equipment provided by the embodiment of the application comprises, but is not limited to, a mobile phone, a tablet computer, a camera, a wearable device and the like.
The inverter grid-connected method is applied to a photovoltaic system comprising a PID (Potential Induced Degradation, potential induced attenuation effect) power supply. As shown in fig. 2, the inverter grid-connection method includes: step 210 and step 220.
Step 210, controlling output of a PID power supply before grid connection of a photovoltaic inverter in a photovoltaic system so as to adjust a difference value between a potential of a neutral point of a direct current bus of the photovoltaic inverter and zero to be not more than a first threshold value.
In practical implementation, the potential induced attenuation effect refers to a phenomenon that leakage current exists between glass and packaging materials of a battery assembly under the action of high voltage for a long time, a large amount of charges are accumulated on the surface of the battery, and the passivation effect of the surface of the battery is poor. The severe PID effect can cause the power of a battery pack to decay by more than 50%, thereby affecting the power output of the entire battery pack. Therefore, measures are required to suppress the PID effect of the photovoltaic system. Setting up a PID power supply is a relatively common means of suppressing the PID effect. And a power supply is arranged between the photovoltaic cell and the ground, and the output voltage of the power supply is regulated in a closed loop mode, so that the ground voltage of the cathode of the photovoltaic cell is compensated, and the PID effect is restrained. The above power supply is used to suppress the PID effect and is thus generally called a PID power supply.
Fig. 3 is a schematic diagram of an application scenario of an inverter grid-connected method according to an embodiment of the present application. Fig. 3 shows the structure of the main power loop of a typical photovoltaic system. As shown in fig. 3, the loop is mainly composed of PV (photovoltaic) sources, a boost circuit 310, a photovoltaic inverter 320, a set of grid-connected relays, and a grid 330. Wherein the PV source is used to simulate a photovoltaic panel. The grid 330 may be a three-phase large grid, with the far end of the N line (neutral line) connected to ground PE. C BUS1 and C BUS2 are respectively the upper and lower capacitors of the DC BUS of the photovoltaic inverter 320, and the connection point of the two capacitors is the neutral point BUS_N of the DC BUS of the photovoltaic inverter 320. The neutral point bus_n of the dc BUS of the photovoltaic inverter 320 is floating. The PV source is connected to the boost circuit 310; the boost circuit 310 is connected with the photovoltaic inverter 320; photovoltaic inverter 320 is connected to the set of grid-tie relays.
In some embodiments, BOOST circuit 310 may be a BOOST circuit with MPPT (Maximum Power Point Tracking ) functionality.
In some embodiments, the photovoltaic inverter 320 may be a DC-AC (Direct Current-ALTERNATING CURRENT) inverter. The inverter may be a voltage type three-phase grid-connected inverter.
In some embodiments, photovoltaic inverter 320 employs a Y-grid, and the set of grid-tie relays includes relays K 1、K2、K3 and K 4. Relay K 1、K2、K3 connects one output of photovoltaic inverter 320 with one phase of grid 330 (denoted by A, B, C in fig. 3), respectively; relay K 4 connects the neutral point bus_n of the dc BUS of photovoltaic inverter 320 to the N line of grid 330.
In some embodiments, a filter circuit 340 is provided between the photovoltaic inverter 320 and the set of grid-tie relays. The filter circuit includes an LC filter composed of an inductor L 1、L2、L3 and a capacitor C 1、C2、C3. The inductor L 1 and the capacitor C 1 may form an LC filter for performing filtering processing on one output (corresponding to one phase of the power grid 330, which may be a phase denoted by a in fig. 3) of the photovoltaic inverter 320; inductor L 2 and capacitor C 2 may form an LC filter for filtering the other output of photovoltaic inverter 320 (corresponding to the other phase of grid 330, which may be the one denoted B in fig. 3); inductor L 3 and capacitor C 3 may form an LC filter for filtering the further output of photovoltaic inverter 320 (which may be a further phase of grid 330, which may be the one denoted by C in fig. 3).
Before the photovoltaic inverter in the photovoltaic system is connected with the power grid, the potential of the neutral point of the direct current BUS of the photovoltaic inverter can be adjusted by controlling the output of the PID power supply until the potential of the neutral point BUS_N of the direct current BUS of the photovoltaic inverter is about zero. The potential of the neutral point of the dc bus of the photovoltaic inverter is the voltage to ground of the neutral point.
In some embodiments, grid-connecting the photovoltaic inverter in the photovoltaic system to the grid is achieved by controlling a grid-connected relay. Specifically, the relay K 1、K2、K3、K4 in fig. 3 may be controlled to be turned off, and then the output of the PID power supply is controlled, so that the potential of the neutral point bus_n of the dc BUS of the photovoltaic inverter 320 is about zero.
The potential of the neutral point bus_n of the dc BUS of the photovoltaic inverter 320 is about zero, and it may be that the difference between the potential of the neutral point bus_n of the dc BUS of the photovoltaic inverter 320 and zero does not exceed the first threshold.
The first threshold value can be preset according to practical conditions such as maximum grid-connected current which can be born by the photovoltaic system. The embodiment of the present application is not particularly limited with respect to the specific value of the first threshold.
Illustratively, the first threshold may be 0.03-0.05V BUS. Wherein V BUS represents the voltage difference between the positive bus+ and the negative BUS-of the dc BUS of the photovoltaic inverter, i.e. the voltage of the dc BUS.
And 220, controlling a grid-connected relay in the photovoltaic system to be closed.
In actual implementation, grid-tie relays are used to connect the photovoltaic system to the grid. In the case where the potential of the neutral point bus_n of the dc BUS of the photovoltaic inverter 320 is zero, the grid-connected relay in the photovoltaic system may be controlled to be closed to achieve grid-connection of the photovoltaic system.
In some embodiments, in the case where the potential of the neutral point bus_n of the dc BUS of the photovoltaic inverter 320 is zero, the relay K 1、K2、K3、K4 in fig. 3 may be controlled to be closed, so as to achieve grid connection of the photovoltaic system and the power grid.
It should be noted that, when the photovoltaic inverter is directly connected to the grid without any measures, the neutral point bus_n of the dc BUS of the photovoltaic inverter is uncontrollable to the potential of the ground line PE, which may cause a larger impact current on the N line of the grid. According to the embodiment of the application, the BUS_N of the direct current BUS of the photovoltaic inverter is directly controlled to have zero potential to the ground wire PE by utilizing the PID power supply in the photovoltaic system, and then grid connection is performed, so that no common mode voltage jump exists on the N lines of the grid before and after grid connection, and grid connection impact current can be completely restrained.
According to the inverter grid-connection method provided by the embodiment of the application, the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is controlled by utilizing the PID power supply in the photovoltaic system to inhibit the N-line impact current during grid connection, and the photovoltaic system is connected only when the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is about zero, because the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is about zero, no common mode voltage jump or extremely small common mode voltage jump (about zero) is caused on the N-line of the grid after grid connection, no grid-connection impact current or extremely small grid-connection impact current (about zero) is generated, no additional hardware circuit or complex calculation and control algorithm is not required, no impact current or extremely small impact current (about zero) on the N-line of the grid during grid connection can be strictly realized, the grid-connection method is simpler, reliable and safe, can be applied to all photovoltaic systems with the PID power supply, and can inhibit the impact current more effectively and with lower cost.
In some embodiments, controlling the output of the PID power source to adjust the potential of the neutral point of the dc bus of the photovoltaic inverter to zero prior to grid-connection of the photovoltaic inverter in the photovoltaic system comprises: and controlling the PID power supply to charge the positive electrode of the direct current bus so that the difference value between the voltage between the positive electrode of the direct current bus and the ground wire and half of the voltage of the direct current bus does not exceed a second threshold value.
In practical implementation, under ideal conditions, before grid connection of the photovoltaic inverter in the photovoltaic system, the output of the PID power supply can be controlled, and the positive BUS+ of the DC BUS of the photovoltaic inverter is charged through the PID power supply until the voltage between the positive BUS+ of the DC BUS of the photovoltaic inverter and the ground line PE isWherein V BUS represents the voltage difference between the positive bus+ and the negative BUS-of the dc BUS of the photovoltaic inverter, i.e. the voltage of the dc BUS.
The voltage difference between the positive bus+ and the neutral point bus_n of the dc BUS of the photovoltaic inverter is:
The voltage V BUS+ of the positive bus+ of the dc BUS of the photovoltaic inverter satisfies:
Since the voltage V BUS+ of the positive bus+ of the dc BUS of the photovoltaic inverter satisfies the above condition and the potential V PE of the ground PE is V PE =0, the voltage between the positive bus+ of the dc BUS of the photovoltaic inverter and the ground PE is Therefore, the voltage V N between the neutral point bus_n of the dc BUS of the photovoltaic inverter and the ground line PE is also equal to zero, i.e., V N＝VPE =0, so that the common mode voltage jump does not exist when the photovoltaic inverter is connected to the grid, and the purpose of no rush current is achieved.
In actual practice, the voltage difference between the voltage V BUS+ of the positive bus+ and the neutral point BUS_N of the DC BUS of the photovoltaic inverter is controlled to be close toCan effectively reduce the grid-connected current without strictly controlling the voltage difference to be equal to
In some embodiments, V BUS+-VN may be connected to the positive electrode of the DC bus by charging the positive electrodeThe difference value between the voltage V BUS+ and the neutral point BUS_N is not more than a second threshold value so as to meet the voltage difference approach/>, between the voltage V BUS+ of the positive BUS+ of the direct-current BUS of the photovoltaic inverter and the neutral point BUS_N
The second threshold value can be preset according to practical situations such as the maximum grid-connected current which can be born by the photovoltaic system. With respect to the specific value of the second threshold value, embodiments of the present application are not particularly limited.
Illustratively, the second threshold may be 0.45-0.55V BUS, i.e., V BUS+-VN＝0.45-0.55VBUS.
According to the inverter grid-connected method provided by the embodiment of the application, the positive electrode of the direct current bus is charged by controlling the PID power supply, so that the voltage between the positive electrode of the direct current bus and the ground wire is about half of the voltage of the direct current bus, the ground voltage of the neutral point of the direct current bus of the photovoltaic inverter is about zero, no additional hardware circuit and complicated calculation and control algorithm are required to be added, the zero ground voltage of the neutral point of the direct current bus of the photovoltaic inverter and no impact current on the N line of a grid during grid connection can be strictly realized, the method is simpler, more reliable and safer, the method can be applied to all photovoltaic systems with the PID power supply, and the grid-connected impact current can be effectively and cost-effectively suppressed.
In some embodiments, controlling the output of the PID power source to adjust the potential of the neutral point of the dc bus of the photovoltaic inverter to zero prior to grid-connection of the photovoltaic inverter in the photovoltaic system comprises: the PID power supply is controlled to charge the negative electrode of the direct current bus so that the difference between the voltage between the ground wire and the negative electrode of the direct current bus and half of the voltage of the direct current bus does not exceed a third threshold value.
In practical implementation, under ideal conditions, before grid connection of the photovoltaic inverter in the photovoltaic system, the output of the PID power supply can be controlled, and the negative BUS-of the DC BUS of the photovoltaic inverter is charged by the PID power supply until the voltage between the ground wire and the negative BUS-of the photovoltaic inverter isWherein V BUS represents the voltage difference between the positive bus+ and the negative BUS-of the dc BUS of the photovoltaic inverter, i.e. the voltage of the dc BUS. The voltage between the ground and the negative BUS of the photovoltaic inverter is/>I.e. the voltage between the negative BUS-of the photovoltaic inverter and ground is/>
The voltage difference between the neutral point bus_n and the negative electrode BUS-of the dc BUS of the photovoltaic inverter is:
The voltage V BUS- of the negative BUS-of the direct current BUS of the photovoltaic inverter satisfies the following conditions:
Since the voltage V BUS- of the negative BUS of the dc BUS of the photovoltaic inverter satisfies the above condition and the potential V PE of the ground line PE is V PE =0, the voltage between the negative BUS of the photovoltaic inverter and the ground line is Therefore, the voltage V N between the neutral point bus_n of the dc BUS of the photovoltaic inverter and the ground line PE is also equal to zero, i.e., V N＝VPE =0, so that the common mode voltage jump does not exist when the photovoltaic inverter is connected to the grid, and the purpose of no rush current is achieved.
In practice, the voltage difference between the neutral point BUS_N and the negative electrode BUS of the DC BUS of the photovoltaic inverter is controlled to be close toCan effectively reduce grid-connected current without strictly controlling the voltage difference to be equal to/>
In some embodiments, V N-VBUS- may be connected to the negative electrode of the DC bus by charging the negative electrodeThe difference between the neutral point BUS-N and the negative electrode BUS-does not exceed a third threshold value so as to meet the voltage difference approach/>, between the neutral point BUS-N and the negative electrode BUS-of a direct current BUS of the photovoltaic inverter
The third threshold value can be preset according to practical situations such as the maximum grid-connected current which can be born by the photovoltaic system. As for the specific value of the third threshold value, the embodiment of the present application is not particularly limited.
Illustratively, the third threshold may be 0.475-0.525V BUS, i.e., V BUS+-VN＝0.475-0.525VBUS.
In some embodiments, the third threshold may or may not be equal to the second threshold.
According to the inverter grid-connected method provided by the embodiment of the application, the negative electrode of the direct current bus is charged by controlling the PID power supply, so that the voltage between the ground wire and the negative electrode of the direct current bus is about half of the voltage of the direct current bus, the ground voltage of the neutral point of the direct current bus of the photovoltaic inverter is about zero, no additional hardware circuit and complicated calculation and control algorithm are required to be added, the ground voltage of the neutral point of the direct current bus of the photovoltaic inverter is zero, no impact current exists on the N line of the grid during grid connection, the grid-connected method is simpler, more reliable and safer, the method can be applied to all photovoltaic systems with the PID power supply, and grid-connected impact current can be effectively and cost-effectively restrained.
In some embodiments, the PID power source comprises a first relay, a second relay, a third relay, and a fourth relay; the first relay is used for connecting the positive pole of the direct current bus; the second relay is used for connecting the negative electrode of the direct current bus; the third relay is used for connecting a photovoltaic panel in the photovoltaic system; the fourth relay is used for connecting the ground wire.
In an actual implementation, controlling the output of the PID power source may be achieved by controlling a relay comprised by the PID power source.
Fig. 4 is a schematic structural diagram of a PID power supply in an inverter grid-connection method according to an embodiment of the present application. As shown in fig. 4, a PID power source may include a DC source, an isolated converter 410, and a relay group. The DC source is connected to the isolation transformer 410; the isolation transformer 410 is connected to the relay group.
The relay group may include a first relay K 5, a second relay K 6, a third relay K 7, and a fourth relay K 8. One end of the first relay K 5 can be used as a first output end of a PID power supply, and can be connected to an anode BUS+ of a direct current BUS of the photovoltaic inverter in a closed state; one end of the second relay K 6 can be used as a second output end of the PID power supply and can be connected to a negative BUS-of a direct current BUS of the photovoltaic inverter in a closed state; the third relay K 7 can be used as a third output end of the PID power supply, and in a closed state, can be connected to a photovoltaic panel (in particular, can be connected to a negative pole PV-) in the photovoltaic system; the fourth relay K 8 may be used as a fourth output of the PID power supply, and in a closed state may be connected to the ground line PE and thus to the neutral point bus_n of the dc BUS of the photovoltaic inverter.
Before grid connection of the photovoltaic inverter, the output of the PID power supply can be added to BUS+/PE (or BUS-/PE) by controlling a relay group of the PID power supply, and the BUS+/PE (or BUS-/PE) is charged by the PID power supply, so that no common mode voltage jump exists when the photovoltaic inverter is grid connected, and the purpose of no impact current is achieved.
Control PID power to charge the positive pole of direct current busbar, include: and controlling the first relay and the fourth relay to be closed, and charging the anode of the direct current bus.
In actual implementation, before grid connection of the photovoltaic inverter, the output of the PID power supply can be added to the positive bus+ of the direct current BUS of the photovoltaic inverter and the ground line PE by controlling the relay group of the PID power supply, so that the positive bus+ of the direct current BUS of the photovoltaic inverter is charged.
In some embodiments, the first relay K 5 and the fourth relay K 8 may be controlled to close, the output of the PID power supply is applied to the positive BUS+ and the ground PE of the DC BUS of the photovoltaic inverter, and the PID power supply is controlled to charge the DC BUS of the photovoltaic inverter to about between the positive BUS+ and the ground PEAt the moment, the voltage of the neutral point BUS_N of the direct current BUS of the photovoltaic inverter to the ground line PE is about 0, and the grid-connected relay K 4 is closed again, so that no common mode voltage jump on the N line of the power grid can be realized, grid-connected impact current cannot be generated, and the effect of inhibiting the grid-connected impact current on the N line of the power grid is achieved.
According to the inverter grid-connected method provided by the embodiment of the application, the relay included in the PID power supply is controlled, the output of the PID power supply is added to the positive BUS+ and the ground line PE of the direct current BUS of the photovoltaic inverter, BUS+/PE is charged, the dynamic adjustment of the neutral point BUS_N of the direct current BUS of the photovoltaic inverter to the potential of the N line of the power grid can be realized, the common mode voltage jump of the N line of the power grid is about zero when the photovoltaic inverter is connected, and therefore grid-connected impact current is inhibited.
In some embodiments, the PID power source comprises a first relay, a second relay, a third relay, and a fourth relay; the first relay is used for connecting the positive pole of the direct current bus; the second relay is used for connecting the negative electrode of the direct current bus; the third relay is used for connecting a photovoltaic panel in the photovoltaic system; the fourth relay is used for connecting the ground wire.
In practical implementation, the specific structure of the PID power supply can be referred to the foregoing embodiments, and will not be described herein.
Controlling the PID power supply to charge the negative electrode of the direct current bus, comprising: and controlling the second relay and the fourth relay to be closed, and charging the negative electrode of the direct current bus.
In a practical implementation, the output of the PID power supply can be applied to the negative BUS-of the DC BUS of the photovoltaic inverter and the ground PE by controlling the relay group of the PID power supply before the grid connection of the photovoltaic inverter, so as to charge the negative BUS-of the DC BUS of the photovoltaic inverter.
In some embodiments, the second relay K 6 and the fourth relay K 8 may be controlled to close, the output of the PID power supply is applied to the negative BUS-and the ground PE of the DC BUS of the photovoltaic inverter, and the PID power supply is controlled to charge between the negative BUS-and the ground PE of the DC BUS of the photovoltaic inverter to aboutAt the moment, the voltage of the neutral point BUS_N of the direct current BUS of the photovoltaic inverter to the ground line PE is about 0, and the grid-connected relay K 4 is closed again, so that no common mode voltage jump on the N line of the power grid can be realized, grid-connected impact current cannot be generated, and the effect of inhibiting the grid-connected impact current on the N line of the power grid is achieved.
According to the inverter grid-connected method provided by the embodiment of the application, the output of the PID power supply is added to the negative BUS-and the ground line PE of the direct current BUS of the photovoltaic inverter by controlling the relay included in the PID power supply, and the BUS-/PE is charged, so that the dynamic adjustment of the neutral point BUS_N of the direct current BUS of the photovoltaic inverter to the potential of the N line of the power grid can be realized, and the common-mode voltage jump of the N line power grid is about zero when the photovoltaic inverter is connected, thereby inhibiting grid-connected impact current.
According to the inverter grid-connected method provided by the embodiment of the application, the execution main body can be an inverter grid-connected device. In the embodiment of the application, an inverter grid-connected device executing an inverter grid-connected method is taken as an example, and the inverter grid-connected device provided by the embodiment of the application is described.
The embodiment of the application also provides an inverter grid-connected device. The inverter grid-connected device can be applied to a photovoltaic system comprising a PID power supply.
As shown in fig. 5, the inverter grid-connected device includes: a first control module 510 and a second control module 520.
The first control module 510 is configured to control an output of the PID power supply to adjust a difference between a potential of a neutral point of a dc bus of the photovoltaic inverter and zero to not exceed a first threshold before grid-connection of the photovoltaic inverter in the photovoltaic system;
a second control module 520 is used to control the grid-tie relay in the photovoltaic system to close.
According to the inverter grid-connected device provided by the embodiment of the application, the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is controlled by utilizing the PID power supply in the photovoltaic system to inhibit the N-line impact current during grid connection, and the photovoltaic system is connected only when the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is about zero, because the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is about zero, no common mode voltage jump or extremely small common mode voltage jump (about zero) is caused on the N-line of the grid after grid connection, no grid-connected impact current or extremely small grid-connected impact current (about zero) is generated, no additional hardware circuit or complex calculation and control algorithm is not required, the N-line no impact current or extremely small impact current (about zero) of the grid during grid connection can be strictly realized, the grid-connected inverter grid-connected device is simpler, more reliable and safer, and can realize more effective and lower-cost inhibition of the grid-connected impact current.
In some embodiments, the first control module 510 may be specifically configured to control the PID power source to charge the positive electrode of the dc bus such that the voltage between the positive electrode of the dc bus and the ground is half the voltage of the dc bus.
In some embodiments, the first control module 510 may be specifically configured to control the PID power source to charge the negative electrode of the dc bus such that the voltage between the ground and the negative electrode of the dc bus is half the voltage of the dc bus.
In some embodiments, the PID power source comprises a first relay, a second relay, a third relay, and a fourth relay; the first relay is used for connecting the positive pole of the direct current bus; the second relay is used for connecting the negative electrode of the direct current bus; the third relay is used for connecting a photovoltaic panel in the photovoltaic system; the fourth relay is used for connecting with a ground wire;
The first control module 510 may be specifically configured to control the first relay and the fourth relay to be closed, and charge the positive electrode of the dc bus.
In some embodiments, the PID power source comprises a first relay, a second relay, a third relay, and a fourth relay; the first relay is used for connecting the positive pole of the direct current bus; the second relay is used for connecting the negative electrode of the direct current bus; the third relay is used for connecting a photovoltaic panel in the photovoltaic system; the fourth relay is used for connecting with a ground wire;
the first control module 510 may be specifically configured to control the second relay and the fourth relay to be closed, and charge the negative electrode of the dc bus.
The inverter grid-connected device in the embodiment of the application can be electronic equipment, and can also be a component in the electronic equipment, such as an integrated circuit or a chip. The electronic device may be a terminal, or may be other devices than a terminal. The electronic device may be a Mobile phone, a tablet computer, a notebook computer, a palm computer, a vehicle-mounted electronic device, a Mobile internet appliance (Mobile INTERNET DEVICE, MID), an augmented reality (augmented reality, AR)/Virtual Reality (VR) device, a robot, a wearable device, an ultra-Mobile personal computer (UMPC), a netbook or a Personal Digital Assistant (PDA), etc., and may also be a server, a network attached storage (Network Attached Storage, NAS), a personal computer (personal computer, PC), a Television (TV), a teller machine, a self-service machine, etc., which are not particularly limited in the embodiments of the present application.
The inverter grid-connected device in the embodiment of the application can be a device with an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, and the embodiment of the present application is not limited specifically.
The inverter grid-connected device provided by the embodiment of the application can realize each process realized by the method embodiments of fig. 2 to 4, and in order to avoid repetition, the description is omitted here.
The embodiment of the application also provides a photovoltaic system. The photovoltaic system can comprise a photovoltaic panel, a booster circuit, a photovoltaic inverter, a grid-connected relay, a PID power supply and the inverter grid-connected device provided by any inverter grid-connected device embodiment.
In actual implementation, the photovoltaic system may include a photovoltaic panel (represented by a PV source), a boost circuit 310, a photovoltaic inverter 320, a set of grid-tie relays (including K 1、K2、K3 and K 4), a PID power supply, and the inverter grid-tie devices described above, as shown in fig. 3.
The PV source is connected to the boost circuit 310; the boost circuit 310 is connected with the photovoltaic inverter 320; photovoltaic inverter 320 is connected to the set of grid-tie relays. Relay K 1、K2、K3 connects one output of photovoltaic inverter 320 with one phase of grid 330 (denoted by A, B, C in fig. 3), respectively; relay K 4 connects the neutral point bus_n of the dc BUS of photovoltaic inverter 320 to the N line of grid 330.
The four output ends of the PID power source may be connected to the positive BUS of the dc BUS of the photovoltaic inverter 320, the negative PV of the photovoltaic panel, and the neutral point bus_n of the dc BUS of the photovoltaic inverter 320 through the first relay K 5, the second relay K 6, the third relay K 7, and the fourth relay K 8, respectively.
It will be appreciated that one output of the PID power supply is connected to the negative PV-electrode of the photovoltaic panel, which can be used to suppress the PID effect of the photovoltaic panel; the other three output ends of the PID power supply are respectively connected with the positive BUS+, the negative BUS-and the neutral point BUS_N of the direct current BUS of the photovoltaic inverter 320, and can be used for charging BUS+/PE or BUS-/PE of the direct current BUS, so that the neutral point BUS_N of the direct current BUS is zero to the ground potential, and grid-connected impact current is eliminated.
According to the photovoltaic system provided by the embodiment of the application, the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is controlled by utilizing the PID power supply in the photovoltaic system to inhibit the N-line impact current during grid connection, and the photovoltaic system is connected only when the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is about zero, because the neutral point to ground voltage of the direct current bus of the photovoltaic inverter is about zero, no common mode voltage jump or extremely small common mode voltage jump (about zero) is caused on the N-line of the grid after grid connection, no grid connection impact current or extremely small grid connection impact current (about zero) is generated, no additional hardware circuit or complex calculation and control algorithm is required to be added, and the N-line no impact current or extremely small impact current (about zero) of the grid during grid connection can be strictly realized, so that the grid connection impact current can be inhibited more simply, reliably and safely, and effectively and with lower cost.
In some embodiments, as shown in fig. 6, an electronic device 600 is further provided in the embodiments of the present application, which includes a processor 601, a memory 602, and a computer program stored in the memory 602 and capable of running on the processor 601, where the program, when executed by the processor 601, implements the respective processes of the inverter grid-tie method embodiment described above, and the same technical effects are achieved, so that repetition is avoided and no further description is given here.
The embodiment of the application also provides a non-transitory computer readable storage medium, on which a computer program is stored, which when executed by a processor, realizes the processes of the inverter grid-connected method embodiment, and can achieve the same technical effects, and in order to avoid repetition, the description is omitted here.
Wherein the processor is a processor in the electronic device described in the above embodiment. The readable storage medium includes computer readable storage medium such as computer readable memory ROM, random access memory RAM, magnetic or optical disk, etc.
The embodiment of the application also provides a computer program product, which comprises a computer program, wherein the computer program realizes the inverter grid-connection method when being executed by a processor.
Wherein the processor is a processor in the electronic device described in the above embodiment. The readable storage medium includes computer readable storage medium such as computer readable memory ROM, random access memory RAM, magnetic or optical disk, etc.
The embodiment of the application further provides a chip, the chip comprises a processor and a communication interface, the communication interface is coupled with the processor, the processor is used for running programs or instructions, the processes of the inverter grid-connected method embodiment can be realized, the same technical effects can be achieved, and the repetition is avoided, and the repeated description is omitted.
It should be understood that the chips referred to in the embodiments of the present application may also be referred to as system-on-chip chips, chip systems, or system-on-chip chips, etc.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of the present application is not limited to performing the functions in the order shown or discussed, but may also include performing the functions in a substantially simultaneous manner or in an opposite order depending on the functions involved, e.g., the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.
From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a computer software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) comprising instructions for causing a terminal (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the method according to the embodiments of the present application.
The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are to be protected by the present application.
In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the application, the scope of which is defined by the claims and their equivalents.
Claims (10)
1. An inverter grid-tie method for use in a photovoltaic system including a PID power source, the method comprising:
Before grid connection of a photovoltaic inverter in the photovoltaic system, controlling output of the PID power supply to adjust a difference value between a potential of a neutral point of a direct current bus of the photovoltaic inverter and zero to be not more than a first threshold value;
And controlling a grid-connected relay in the photovoltaic system to be closed.
2. The inverter grid-tie method of claim 1 wherein controlling the output of the PID power source to adjust the difference between the potential of the neutral point of the dc bus of the photovoltaic inverter and zero to not exceed a first threshold value prior to grid-tie of the photovoltaic inverter in the photovoltaic system comprises:
And controlling the PID power supply to charge the positive electrode of the direct current bus so that the difference value between the voltage between the positive electrode of the direct current bus and the ground wire and half of the voltage of the direct current bus does not exceed a second threshold value.
3. The inverter grid-tie method of claim 1 wherein controlling the output of the PID power source to adjust the difference between the potential of the neutral point of the dc bus of the photovoltaic inverter and zero to not exceed a first threshold value prior to grid-tie of the photovoltaic inverter in the photovoltaic system comprises:
And controlling the PID power supply to charge the negative electrode of the direct current bus so that the difference value between the voltage between the ground wire and the negative electrode of the direct current bus and half of the voltage of the direct current bus does not exceed a third threshold value.
4. The inverter grid-tie method of claim 2 wherein the PID power source comprises a first relay, a second relay, a third relay and a fourth relay; the first relay is used for connecting the positive electrode of the direct current bus; the second relay is used for connecting the negative electrode of the direct current bus; the third relay is used for connecting a photovoltaic panel in the photovoltaic system; the fourth relay is used for being connected with the ground wire;
the control of the PID power supply to charge the anode of the direct current bus comprises the following steps:
and controlling the first relay and the fourth relay to be closed, and charging the anode of the direct current bus.
5. The inverter grid-tie method of claim 3 wherein the PID power source comprises a first relay, a second relay, a third relay and a fourth relay; the first relay is used for connecting the positive electrode of the direct current bus; the second relay is used for connecting the negative electrode of the direct current bus; the third relay is used for connecting a photovoltaic panel in the photovoltaic system; the fourth relay is used for being connected with the ground wire;
The control of the PID power supply to charge the negative electrode of the direct current bus comprises the following steps:
and controlling the second relay and the fourth relay to be closed, and charging the negative electrode of the direct current bus.
6. An inverter grid-tie device for use in a photovoltaic system including a PID power source, the device comprising:
The first control module is used for controlling the output of the PID power supply before grid connection of the photovoltaic inverter in the photovoltaic system so as to adjust the difference value between the potential of the neutral point of the direct current bus of the photovoltaic inverter and zero to be not more than a first threshold value;
And the second control module is used for controlling the grid-connected relay in the photovoltaic system to be closed.
7. A photovoltaic system comprising a photovoltaic panel, a boost circuit, a photovoltaic inverter, a grid-tie relay, a PID power source, and the inverter grid-tie device of claim 6.
8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the inverter grid tie method of any one of claims 1-5 when the program is executed by the processor.
9. A non-transitory computer readable storage medium having stored thereon a computer program, which when executed by a processor implements the inverter grid tie method of any of claims 1-5.
10. A computer program product comprising a computer program which, when executed by a processor, implements the inverter grid tie method of any one of claims 1-5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410117528.0A CN117996850A (en) | 2024-01-26 | 2024-01-26 | Inverter grid connection method and device and photovoltaic system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410117528.0A CN117996850A (en) | 2024-01-26 | 2024-01-26 | Inverter grid connection method and device and photovoltaic system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117996850A true CN117996850A (en) | 2024-05-07 |
Family
ID=90892822
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410117528.0A Pending CN117996850A (en) | 2024-01-26 | 2024-01-26 | Inverter grid connection method and device and photovoltaic system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117996850A (en) |
-
2024
- 2024-01-26 CN CN202410117528.0A patent/CN117996850A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104953606B (en) | Networked layered compensation method for voltage unbalance of PCC (Point of Common Coupling) of islanded microgrid | |
| Jain et al. | Single‐phase single‐stage multifunctional grid interfaced solar photo‐voltaic system under abnormal grid conditions | |
| Galeshi et al. | Dynamic voltage restorer employing multilevel cascaded H‐bridge inverter | |
| Jalilian et al. | DC‐link fault current limiter‐based fault ride‐through scheme for inverter‐based distributed generation | |
| CN112769115B (en) | Self-adaptive active full-compensation control method for grounding residual current | |
| CN108933540B (en) | Fault quick recovery control method and device for flexible direct current transmission system | |
| CN111404221B (en) | Control method, control device, control equipment and storage medium of charging module | |
| CN108923430A (en) | Active Power Filter-APF neural network overall situation fast terminal sliding-mode control and calculating equipment | |
| Pal et al. | A comparative analysis of different magnetics supported three-phase four-wire unified power quality conditioners–a simulation study | |
| CN104065285A (en) | Grid-connected inverter system | |
| Marei et al. | PV interface system with LVRT capability based on a current controlled HFAC link converter | |
| Jarwar et al. | High dynamic performance power quality conditioner for AC microgrids | |
| Sarita et al. | Control strategies for power quality enrichment in Distribution network using UPQC | |
| Noroozi et al. | Power quality improvement in single-phase transformerless semi-quasi-Z-source inverters for off-grid photovoltaic systems | |
| CN109638791B (en) | Direct-current disconnection protection method of multi-terminal flexible direct-current power distribution system | |
| Shivam et al. | Real‐time implementation of SPV system with DSTATCOM capabilities in three‐phase four‐wire distribution system | |
| CN110932232A (en) | Longitudinal zero-sequence impedance turn-to-turn protection method and device for series transformer | |
| Malakondaiah et al. | Second harmonic impedance drift‐based islanding detection method | |
| US20190265663A1 (en) | Method And Control System For Controlling A Voltage Source Converter Using Power-Synchronization Control | |
| Wang et al. | A novel directional element for transmission line connecting inverter-interfaced renewable energy power plant | |
| CN113595430A (en) | Three-loop controller of LCL type grid-connected inverter and parameter design method thereof | |
| US20230318440A1 (en) | Method and apparatus for suppressing cross current in inverter parallel system | |
| Wang et al. | Suppression strategy on neutral point overvoltage in resonant grounding system considering single line-to-ground fault | |
| CN117996850A (en) | Inverter grid connection method and device and photovoltaic system | |
| CN106998075A (en) | Suppress the method and system of the 12 pulsation follow-up commutation failures of inverter of IGCT |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |