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CN-121984319-A - Photovoltaic power generation system, photovoltaic inverter and control method of photovoltaic inverter

CN121984319ACN 121984319 ACN121984319 ACN 121984319ACN-121984319-A

Abstract

The application discloses a photovoltaic power generation system, a photovoltaic inverter and a control method thereof, belonging to the technical field of new energy, wherein the photovoltaic inverter comprises: the total number of the photovoltaic modules in the photovoltaic system is ; A shutdown circuit module, The input ends of the shut-down circuit modules are respectively connected with The photovoltaic modules are connected in a one-to-one correspondence manner and The output ends of the shut-down circuit modules are divided into Respectively with groups of The power channels are connected for opposite The on state of each photovoltaic module is controlled one by one, and the control chip is connected with The turn-off circuit modules are connected and used for controlling the on state of each turn-off circuit module according to at least one operation parameter in the photovoltaic system, each photovoltaic module and each power channel so as to ensure the safe operation of the photovoltaic system. The photovoltaic inverter can enable the photovoltaic system to have quick turn-off capability, and meanwhile, the cost required by the photovoltaic system can be reduced, and the power expansion capability of the photovoltaic system can not be limited.

Inventors

  • ZHANG JIABING
  • XU TIEZHU
  • MI LIN

Assignees

  • 深圳市英威腾光伏科技有限公司

Dates

Publication Date
20260505
Application Date
20260210

Claims (10)

  1. 1. A photovoltaic inverter, comprising: Each power channel can track at least the maximum power point of 1 photovoltaic module in the photovoltaic system, and the total number of the photovoltaic modules in the photovoltaic system is ; , ; The circuit module is turned off in a number of ways, The input ends of the shut-down circuit modules are respectively connected with The photovoltaic modules are connected in a one-to-one correspondence manner and The output ends of the shut-down circuit modules are divided into Respectively with groups of The power channels are connected for opposite The conducting states of the photovoltaic modules are controlled one by one; Control chip, and The turn-off circuit modules are connected and used for controlling the on state of each turn-off circuit module according to at least one operation parameter in the photovoltaic system, each photovoltaic module and each power channel so as to ensure the safe operation of the photovoltaic system.
  2. 2. The photovoltaic inverter of claim 1, wherein if the target shutdown circuit module is When any one of the shutdown circuit modules is used for shutting down the circuit module and the target photovoltaic module is connected with the target power channel through the target shutdown circuit module, the target shutdown circuit module comprises a switch unit for controlling the conduction state of the target photovoltaic module and a unidirectional conduction device for bypassing the target photovoltaic module; The switch unit is connected between the anode of the target photovoltaic module and the target power channel, and the unidirectional conduction device is connected between the cathode of the target photovoltaic module and the target power channel.
  3. 3. A photovoltaic inverter according to claim 2, characterized in that the unidirectional conducting device is in particular a diode; the anode of the diode is connected with the cathode of the target photovoltaic module, and the cathode of the diode is connected with the target power channel.
  4. 4. The photovoltaic inverter of claim 2, wherein the switching unit comprises a relay, a first resistor, a second resistor, and a first switching tube; The first end of the first resistor is used for receiving a power signal, the second end of the first resistor is connected with the positive electrode of the control coil in the relay, the negative electrode of the control coil in the relay is connected with the first end of the first switch tube, the second end of the first switch tube is grounded, the first end of the relay is connected with the target power channel, the second end of the relay is connected with the positive electrode of the target photovoltaic module, the control end of the first switch tube is connected with the first end of the second resistor, and the second end of the second resistor is used for receiving the control signal sent by the control chip.
  5. 5. The photovoltaic inverter of claim 2, wherein the switching unit comprises an optocoupler, a third resistor, a voltage dividing module and a second switching tube; The first end of the optical coupler is connected with the first end of the third resistor, the second end of the third resistor is used for receiving a control signal sent by the control chip, the second end of the optical coupler is grounded, the third end of the optical coupler is connected with the control end of the second switching tube through the voltage dividing module, the first end of the second switching tube is connected with the target power channel, the second end of the second switching tube is connected with the positive electrode of the target photovoltaic module, and the fourth end of the optical coupler is connected with the negative electrode of the target photovoltaic module.
  6. 6. The photovoltaic inverter of claim 5, wherein the voltage dividing module comprises a fourth resistor, a fifth resistor, and a zener diode; The first end of the fourth resistor is connected with the third end of the optocoupler, the second end of the fourth resistor is respectively connected with the first end of the fifth resistor, the control end of the second switching tube and the positive electrode of the zener diode, and the second end of the fifth resistor, the negative electrode of the zener diode and the second end of the second switching tube are all connected with the positive electrode of the target photovoltaic module.
  7. 7. The photovoltaic inverter of claim 2, wherein the target power path comprises a first inductor, a first capacitor, a second capacitor, a transformer, a second inductor, and third, fourth, fifth, and sixth switching tubes; The first end of the first inductor is connected with the first end of the first capacitor, the second end of the first inductor is connected with the first end of the second capacitor, the first end of the third switch tube and the first end of the fourth switch tube respectively, the second end of the third switch tube is connected with the first end of the fifth switch tube and the first end of the primary side of the transformer respectively, the second end of the fourth switch tube is connected with the first end of the sixth switch tube and the second end of the primary side of the transformer respectively, the second end of the sixth switch tube is connected with the second end of the fifth switch tube, the second end of the second capacitor and the first end of the first capacitor respectively, and the first end of the secondary side of the transformer is connected with the first end of the second inductor; Correspondingly, the first end of the first inductor and the second end of the first capacitor are input ends of the target power channel, and the second end of the second inductor and the second end of the secondary side of the transformer are output ends of the target power channel.
  8. 8. A control method of a photovoltaic inverter, characterized by being applied to a control chip in a photovoltaic inverter according to any one of claims 1 to 7, comprising: And controlling the on state of each turn-off circuit module according to at least one operation parameter in the photovoltaic system, each photovoltaic module and each power channel so as to ensure the safe operation of the photovoltaic system.
  9. 9. The method according to claim 8, wherein the controlling the on state of each shutdown circuit module according to at least one operation parameter of the photovoltaic system, each photovoltaic module, and each power channel to ensure safe operation of the photovoltaic system comprises: Acquiring electrical operation parameters of each photovoltaic module to obtain module operation parameters; If it is determined according to the operation parameters of the assembly And if the photovoltaic module with abnormal operation exists in the photovoltaic modules, the shutdown circuit module connected with the photovoltaic module with abnormal operation is shut down so as to ensure the safe operation of the photovoltaic system.
  10. 10. The method according to claim 8, wherein the controlling the on state of each shutdown circuit module according to at least one operation parameter of the photovoltaic system, each photovoltaic module, and each power channel to ensure safe operation of the photovoltaic system comprises: acquiring electrical operation parameters of each power channel to obtain channel operation parameters; If it is determined according to the channel operation parameters And if the power channels with abnormal operation exist in the power channels, all the shutdown circuit modules connected with the power channels with abnormal operation are shut down so as to ensure the safe operation of the photovoltaic system.

Description

Photovoltaic power generation system, photovoltaic inverter and control method of photovoltaic inverter Technical Field The invention relates to the technical field of new energy, in particular to a photovoltaic power generation system, a photovoltaic inverter and a control method thereof. Background The existing photovoltaic system is generally required to have quick Shutdown (Rapid Shutdown) capability, so that the output voltage of the direct current side of the photovoltaic system can be quickly reduced to a safe level when the photovoltaic system encounters an emergency, and the safe operation of the photovoltaic system is further ensured. In the prior art, two topology architectures are typically used to enable a photovoltaic system with a fast turn-off capability. Referring to fig. 1 and 2, fig. 1 is a topology diagram of a micro-photovoltaic system with a quick turn-off capability, and fig. 2 is a topology diagram of a string photovoltaic system with a quick turn-off capability. In fig. 1 and 2, PV represents a photovoltaic module. As shown in fig. 1, in order to enable the micro photovoltaic system to have a quick turn-off capability, only one photovoltaic module can be connected to one power channel of the micro inverter, and under the configuration, the micro inverter only needs to directly control the conduction state of each photovoltaic module at the moment due to the lower channel voltage of each power channel. But such an arrangement not only severely limits the power spreading capability of the photovoltaic system, but the cost of the arrangement required for a photovoltaic system of comparable power class is also significantly higher. As shown in fig. 2, in order to enable the string photovoltaic system to have a quick turn-off capability, a turn-off device needs to be configured for each photovoltaic module separately, and since each power channel of the string inverter is connected with a plurality of photovoltaic modules, the channel voltage of the power channel is too high, and therefore, under the circuit architecture, a turn-off device control chip for controlling each turn-off device needs to be arranged specially to ensure safe and stable operation of the photovoltaic system. Referring to fig. 3, fig. 3 is an internal structure diagram of the shutoff in fig. 2. As can be seen from fig. 3, the shutdown device is provided with an independent auxiliary power supply, a signal sampling module, a processor, a driving unit and the like, so that the string photovoltaic system needs to have high cost when realizing the quick shutdown capability. Therefore, how to make the photovoltaic system have the capability of quick turn-off, not only can reduce the cost required by the photovoltaic system, but also can not limit the power expansion capability of the photovoltaic system is a technical problem to be solved by the skilled person. Disclosure of Invention In view of the above, the present invention is directed to a photovoltaic power generation system, a photovoltaic inverter and a control method thereof, so that the photovoltaic system has a fast shutdown capability, and the cost required by the photovoltaic system can be reduced, and the power expansion capability of the photovoltaic system is not limited. The specific scheme is as follows: In order to solve the above technical problems, the present invention provides a photovoltaic inverter, including: Each power channel can track at least the maximum power point of 1 photovoltaic module in the photovoltaic system, and the total number of the photovoltaic modules in the photovoltaic system is ;,; The circuit module is turned off in a number of ways,The input ends of the shut-down circuit modules are respectively connected withThe photovoltaic modules are connected in a one-to-one correspondence manner andThe output ends of the shut-down circuit modules are divided intoRespectively with groups ofThe power channels are connected for oppositeThe conducting states of the photovoltaic modules are controlled one by one; Control chip, and The turn-off circuit modules are connected and used for controlling the on state of each turn-off circuit module according to at least one operation parameter in the photovoltaic system, each photovoltaic module and each power channel so as to ensure the safe operation of the photovoltaic system. Preferably, if the target shutdown circuit module isWhen any one of the shutdown circuit modules is used for shutting down the circuit module and the target photovoltaic module is connected with the target power channel through the target shutdown circuit module, the target shutdown circuit module comprises a switch unit for controlling the conduction state of the target photovoltaic module and a unidirectional conduction device for bypassing the target photovoltaic module; The switch unit is connected between the anode of the target photovoltaic module and the target power channel, and the unidirectional conduction d