CN117477933A - Photovoltaic optimizer and inverter - Google Patents

Photovoltaic optimizer and inverter Download PDF

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Publication number
CN117477933A
CN117477933A CN202311523208.7A CN202311523208A CN117477933A CN 117477933 A CN117477933 A CN 117477933A CN 202311523208 A CN202311523208 A CN 202311523208A CN 117477933 A CN117477933 A CN 117477933A
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CN
China
Prior art keywords
communication
inductor
inductance
communication inductor
inverter
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CN202311523208.7A
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Chinese (zh)
Inventor
邓国良
唐佳棋
望庆磊
谢建明
吴宝善
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Huawei Digital Power Technologies Co Ltd
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Huawei Digital Power Technologies Co Ltd
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Priority to CN202311523208.7A priority Critical patent/CN117477933A/en
Publication of CN117477933A publication Critical patent/CN117477933A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
    • 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
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
    • H02J13/00007—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using the power network as support for the transmission
    • 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
    • H02J3/381—Dispersed generators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
    • H02M7/53871—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
    • H02M7/53875—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current with analogue control of three-phase output
    • 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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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Inverter Devices (AREA)

Abstract

The application provides a photovoltaic optimizer and dc-to-ac converter, photovoltaic optimizer includes voltage conversion circuit, first communication inductance, second communication inductance, communication transformer and controller, and first communication inductance first end and second communication inductance first end link to each other with voltage conversion circuit positive pole output and negative pole output, and first communication inductance second end and second communication inductance second end are respectively through power line connection power converter positive pole input and negative pole input, and first communication inductance and second communication inductance impedance are equal. The second end of the first communication inductor and the second end of the second communication inductor are respectively connected with the primary winding of the communication transformer, the first communication inductor and the second communication inductor receive a first high-frequency voltage component from the power converter through a power line, and the communication transformer is used for transforming the first high-frequency voltage component on the first communication inductor and the second communication inductor. The controller is used for demodulating the transformed first high-frequency voltage component to acquire the information of the electric quantity transmitted by the power converter.

Description

Photovoltaic optimizer and inverter
Technical Field
The application relates to the field of power electronics, in particular to a photovoltaic optimizer and an inverter.
Background
The power line carrier communication (Power Line Carr ier, abbreviated as PLC) uses a power line as a transmission medium, and utilizes a signal modulation mode to change an analog or digital signal into a high-frequency signal, so that the remote signal transmission is realized through the power line, and the power line carrier communication has the advantages of high signal transmission reliability, safety, confidentiality and the like, and is widely applied to data communication scenes of inconvenient wiring or long distance, high speed and multiple nodes. The power line carrier communication can be applied to data interaction between power devices such as a photovoltaic optimizer and an inverter in a photovoltaic system, and a PLC inductor is connected in series to an output port or an input port of each power device, and PLC signal transformers are connected in parallel to two ends of the PLC inductor.
The inventor of the application finds that in the research and experiment process, as the output port or the input port of each power device is connected with one PLC inductor in series, the line impedance on the positive and negative lines of the output port or the input port of the power device is inconsistent, so that differential mode noise is generated in the working process of the power device, and the generated differential mode noise cannot be effectively filtered, so that the differential mode noise exceeds the standard, and the electromagnetic compatibility effect is poor.
Disclosure of Invention
The embodiment of the application provides a photovoltaic optimizer and an inverter, which can avoid noise from affecting the normal operation of related equipment in a photovoltaic system and further improve the electromagnetic compatibility effect.
In a first aspect, the present application provides a photovoltaic optimizer, the photovoltaic optimizer includes voltage conversion circuit, first communication inductance, second communication inductance, communication transformer and controller, voltage conversion circuit's input is used for connecting photovoltaic module, the first end of first communication inductance and the first end of second communication inductance link to each other with voltage conversion circuit's positive pole output and negative pole output respectively, the second end of first communication inductance and the second end of second communication inductance are respectively through the positive pole input and the negative pole input of power converter of power line connection, the impedance of first communication inductance and second communication inductance equals. The second end of the first communication inductor and the second end of the second communication inductor are also respectively connected with a primary winding of a communication transformer, the first communication inductor and the second communication inductor receive a first high-frequency voltage component from the power converter through a power line, and the communication transformer is used for transforming the first high-frequency voltage component on the first communication inductor and the second communication inductor. The controller is used for demodulating the transformed first high-frequency voltage component to acquire electric quantity information transmitted by the power converter.
In the application, in the working process of the photovoltaic optimizer, the circuit impedance on the positive electrode output end and the negative electrode output end of the voltage conversion circuit is equal, so that the common mode noise source of the photovoltaic optimizer is prevented from being converted into differential mode noise, the generated common mode current can be reduced by adding a common mode inductance and other modes into the photovoltaic optimizer, the noise is prevented from affecting the normal operation of related equipment in a photovoltaic system, and the electromagnetic compatibility effect is further improved.
In one possible implementation manner, the photovoltaic optimizer includes a common-mode inductor, and the magnetic core of the common-mode inductor includes two coils with opposite directions and the same number of turns, one ends of the two coils are respectively connected with the positive output end and the negative output end of the voltage conversion circuit, and the other ends of the two coils are respectively connected with the first end of the first communication inductor and the first end of the second communication inductor. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When the common mode current flows through the common mode inductor, the common mode inductor can reduce the generated common mode current, thereby avoiding noise from influencing the normal operation of related equipment in the photovoltaic system and further improving the electromagnetic compatibility effect.
In one possible implementation, the first communication inductor and the second communication inductor are coupled on one magnetic core, winding directions of the first communication inductor and the second communication inductor are opposite and the winding directions of the first communication inductor and the second communication inductor are the same, a first end of the first communication inductor and a first end of the second communication inductor are same-name ends, and leakage inductance between the first communication inductor and the second communication inductor is larger than a set threshold value. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When common mode current flows through the first communication inductor and the second communication inductor, the first communication inductor and the second communication inductor can reduce the generated common mode current, so that noise is prevented from influencing normal operation of related equipment in the photovoltaic system, and the electromagnetic compatibility effect is further improved. In addition, by using leakage inductance between the first communication inductance and the second communication inductance as communication inductance in power line carrier communication, device cost is further saved.
In one possible implementation manner, the first communication inductor, the second communication inductor and the communication transformer are coupled on one magnetic core, winding directions of the first communication inductor and the second communication inductor are opposite and the winding directions of the first communication inductor and the second communication inductor are the same, the first end of the first communication inductor and the first end of the second communication inductor are homonymous ends, and leakage inductance between the first communication inductor and the second communication inductor is larger than a set threshold value. The first communication inductance and the second communication inductance are used as primary windings of a communication transformer, secondary windings of the communication transformer are coupled to the magnetic core, and the transformation ratio of the communication transformer changes along with the change of leakage inductance between the first communication inductance and the second communication inductance. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When the common-mode current flows through the first communication inductor and the second communication inductor, the first communication inductor and the second communication inductor can reduce the generated common-mode current, so that noise is prevented from influencing the normal operation of related equipment in the photovoltaic system, and the electromagnetic compatibility effect is further improved. In addition, by using leakage inductance between the first communication inductance and the second communication inductance as the communication inductance in the power line carrier communication and using the first communication inductance and the second communication inductance as the primary winding of the communication transformer, the device cost is further saved.
In one possible implementation, the photovoltaic optimizer includes a filter inductor connected between the positive output of the voltage conversion circuit and the first communication inductor. Here, the filter inductance may be used to reduce differential mode noise generated by the voltage conversion circuit in the photovoltaic optimizer.
In one possible implementation, the controller is configured to generate the second high frequency voltage component based on modulation of electrical quantity information of the voltage conversion circuit. The communication transformer may transform based on the second high frequency voltage component and output to the power line to transmit electrical quantity information of the voltage conversion circuit to the power converter.
In one possible implementation, the voltage conversion circuit includes an input capacitor and an output capacitor, two ends of the input capacitor are used for connecting the photovoltaic component, and two ends of the output capacitor are used for coupling with the first communication inductor and the second communication inductor. The voltage conversion circuit further comprises a first switching tube and a second switching tube, the first switching tube and the second switching tube are connected in series and then connected in parallel to two ends of the input capacitor, the connecting ends of the first switching tube and the second switching tube are connected with one end of the output capacitor through an inductor, and the other end of the output capacitor is connected with the connecting ends of the second switching tube and the input capacitor. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise.
In a second aspect, the application provides an inverter, the inverter includes inverter circuit, first communication inductance, second communication inductance, communication transformer and controller, inverter circuit's output is used for connecting alternating current load, the first end of first communication inductance and the first end of second communication inductance link to each other with inverter circuit's anodal input and negative pole input respectively, the second end of first communication inductance and the second end of second communication inductance are respectively through the anodal output and the negative pole output of power line connection photovoltaic optimizer, the impedance of first communication inductance and second communication inductance equals. The second end of the first communication inductor and the second end of the second communication inductor are also respectively connected with a primary winding of a communication transformer, the first communication inductor and the second communication inductor receive a first high-frequency voltage component from the photovoltaic optimizer through a power line, and the communication transformer is used for transforming the first high-frequency voltage component on the first communication inductor and the second communication inductor. The controller is used for demodulating the transformed first high-frequency voltage component to acquire the electrical quantity information transmitted by the photovoltaic optimizer.
In the application, in the working process of the inverter, the circuit impedance on the positive electrode output end and the negative electrode output end of the inverter circuit is equal, so that the common mode noise source of the inverter is prevented from being converted into differential mode noise, and the generated common mode current can be reduced by adding a common mode inductance and other modes in the inverter, thereby avoiding the noise from affecting the normal operation of related equipment in a photovoltaic system and further improving the electromagnetic compatibility effect.
In one possible implementation manner, the inverter includes a common-mode inductor, and the magnetic core of the common-mode inductor includes two coils with opposite directions and the same number of turns, one ends of the two coils are respectively connected with the positive input end and the negative input end of the inverter circuit, and the other ends of the two coils are respectively connected with the first end of the first communication inductor and the first end of the second communication inductor. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When the common mode current flows through the common mode inductor, the common mode inductor can reduce the generated common mode current, thereby avoiding noise from influencing the normal operation of related equipment in the photovoltaic system and further improving the electromagnetic compatibility effect.
In one possible implementation, the first communication inductor and the second communication inductor are coupled on one magnetic core, winding directions of the first communication inductor and the second communication inductor are opposite and the winding directions of the first communication inductor and the second communication inductor are the same, a first end of the first communication inductor and a first end of the second communication inductor are same-name ends, and leakage inductance between the first communication inductor and the second communication inductor is larger than a set threshold value. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When common mode current flows through the first communication inductor and the second communication inductor, the first communication inductor and the second communication inductor can reduce the generated common mode current, so that noise is prevented from influencing normal operation of related equipment in the photovoltaic system, and the electromagnetic compatibility effect is further improved. In addition, by using leakage inductance between the first communication inductance and the second communication inductance as communication inductance in power line carrier communication, device cost is further saved.
In one possible implementation manner, the first communication inductor, the second communication inductor and the communication transformer are coupled on one magnetic core, winding directions of the first communication inductor and the second communication inductor are opposite and the winding directions of the first communication inductor and the second communication inductor are the same, the first end of the first communication inductor and the first end of the second communication inductor are homonymous ends, and leakage inductance between the first communication inductor and the second communication inductor is larger than a set threshold value. The first communication inductance and the second communication inductance are used as primary windings of a communication transformer, secondary windings of the communication transformer are coupled to the magnetic core, and the transformation ratio of the communication transformer changes along with the change of leakage inductance between the first communication inductance and the second communication inductance. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When the common-mode current flows through the first communication inductor and the second communication inductor, the first communication inductor and the second communication inductor can reduce the generated common-mode current, so that noise is prevented from influencing the normal operation of related equipment in the photovoltaic system, and the electromagnetic compatibility effect is further improved. In addition, by using leakage inductance between the first communication inductance and the second communication inductance as the communication inductance in the power line carrier communication and using the first communication inductance and the second communication inductance as the primary winding of the communication transformer, the device cost is further saved.
In one possible implementation, the inverter includes a filter inductor connected between the positive input of the inverter circuit and the first communication inductor. Here, the filter inductance may be used to reduce differential mode noise generated by an inverter circuit in the inverter.
In one possible implementation, the controller is configured to generate the second high-frequency voltage component based on modulation of electrical quantity information of the inverter circuit. The communication transformer may transform the second high frequency voltage component based on the second high frequency voltage component and output to the power line to transmit electrical quantity information of the inverter circuit to the photovoltaic optimizer.
In one possible implementation manner, the inverter circuit comprises at least one bridge arm, a first bus capacitor and a second bus capacitor which are connected in series, wherein the bridge arm is connected in parallel with two ends of the first bus capacitor and the second bus capacitor which are connected in series, one end of the bridge arm is connected with a connecting end of the first bus capacitor and a connecting end of the second bus capacitor, the other end of the bridge arm is used for connecting an alternating current load, and two ends of the first bus capacitor and the second bus capacitor which are connected in series are used for being coupled with a first communication inductor and a second communication inductor. The circuit impedance on the positive electrode output end and the negative electrode output end of the inverter circuit is equal, so that the common mode noise source of the inverter is prevented from being converted into differential mode noise.
In a third aspect, the present application provides a photovoltaic system, including a photovoltaic optimizer, an inverter, and a photovoltaic module, an input end of the photovoltaic optimizer is connected to the photovoltaic module, an output end of the photovoltaic optimizer is connected to an input end of the inverter, and an output end of the inverter is used for connecting an ac load. The photovoltaic optimizer comprises a voltage conversion circuit, a first communication inductor, a second communication inductor, a first communication transformer and a first controller, wherein the first end of the first communication inductor and the first end of the second communication inductor are respectively connected with the positive output end and the negative output end of the voltage conversion circuit, the second end of the first communication inductor and the second end of the second communication inductor are respectively connected with the positive input end and the negative input end of the inverter through power lines, the impedance of the first communication inductor is equal to that of the second communication inductor, the second end of the first communication inductor and the second end of the second communication inductor are respectively connected with the primary winding of the first communication transformer, the first communication inductor and the second communication inductor receive first high-frequency voltage components from the inverter through the power lines, the first communication transformer is used for transforming the first high-frequency voltage components on the first communication inductor and the second communication inductor, and the first controller is used for demodulating the transformed first high-frequency voltage components to acquire electric quantity information transmitted by the inverter. The inverter comprises an inverter circuit, a third communication inductor, a fourth communication inductor, a second communication transformer and a second controller, wherein the first end of the third communication inductor and the first end of the fourth communication inductor are respectively connected with the positive electrode input end and the negative electrode input end of the inverter circuit, the second end of the third communication inductor and the second end of the fourth communication inductor are respectively connected with the positive electrode output end and the negative electrode output end of the photovoltaic optimizer through power lines, the impedance of the third communication inductor is equal to that of the fourth communication inductor, the second end of the third communication inductor and the second end of the fourth communication inductor are respectively connected with the primary winding of the second communication transformer, the first communication inductor and the second communication inductor receive second high-frequency voltage components from the photovoltaic optimizer through the power lines, the second communication transformer is used for transforming the second high-frequency voltage components on the first communication inductor and the second communication inductor, and the second controller is used for demodulating the transformed second high-frequency voltage components to acquire electric quantity information transmitted by the photovoltaic optimizer.
In the application, in the working process of the photovoltaic optimizer, the circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer is prevented from being converted into differential mode noise. The circuit impedance on the positive electrode output end and the negative electrode output end of the inverter circuit is equal, the conversion of an inverter common mode noise source into differential mode noise can be avoided, the generated common mode current can be reduced by adding common mode inductance and the like in the photovoltaic optimizer and the inverter, the noise is prevented from affecting the normal operation of related equipment in the photovoltaic system, and the electromagnetic compatibility effect is further improved.
In one possible implementation manner, the photovoltaic optimizer includes a common-mode inductor, and the magnetic core of the common-mode inductor includes two coils with opposite directions and the same number of turns, one ends of the two coils are respectively connected with the positive output end and the negative output end of the voltage conversion circuit, and the other ends of the two coils are respectively connected with the first end of the first communication inductor and the first end of the second communication inductor. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When the common mode current flows through the common mode inductor, the common mode inductor can reduce the generated common mode current, thereby avoiding noise from influencing the normal operation of related equipment in the photovoltaic system and further improving the electromagnetic compatibility effect.
In one possible implementation, the first communication inductor and the second communication inductor are coupled on one magnetic core, winding directions of the first communication inductor and the second communication inductor are opposite and the winding directions of the first communication inductor and the second communication inductor are the same, a first end of the first communication inductor and a first end of the second communication inductor are same-name ends, and leakage inductance between the first communication inductor and the second communication inductor is larger than a set threshold value. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When common mode current flows through the first communication inductor and the second communication inductor, the first communication inductor and the second communication inductor can reduce the generated common mode current, so that noise is prevented from influencing normal operation of related equipment in the photovoltaic system, and the electromagnetic compatibility effect is further improved. In addition, by using leakage inductance between the first communication inductance and the second communication inductance as communication inductance in power line carrier communication, device cost is further saved.
In one possible implementation manner, the first communication inductor, the second communication inductor and the first communication transformer are coupled on one magnetic core, winding directions of the first communication inductor and the second communication inductor are opposite and the winding directions are the same, the first end of the first communication inductor and the first end of the second communication inductor are homonymous ends, and leakage inductance between the first communication inductor and the second communication inductor is larger than a set threshold value. The first communication inductance and the second communication inductance are used as primary windings of a first communication transformer, secondary windings of the first communication transformer are coupled on the magnetic core, and the transformation ratio of the first communication transformer changes along with the change of leakage inductance between the first communication inductance and the second communication inductance. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When the common-mode current flows through the first communication inductor and the second communication inductor, the first communication inductor and the second communication inductor can reduce the generated common-mode current, so that noise is prevented from influencing the normal operation of related equipment in the photovoltaic system, and the electromagnetic compatibility effect is further improved. In addition, by using the leakage inductance between the first communication inductance and the second communication inductance as the communication inductance in the power line carrier communication and using the first communication inductance and the second communication inductance as the primary winding of the first communication transformer, the device cost is further saved.
In one possible implementation manner, the inverter includes a common-mode inductor, and the magnetic core of the common-mode inductor includes two coils with opposite directions and the same number of turns, one ends of the two coils are respectively connected with the positive input end and the negative input end of the inverter circuit, and the other ends of the two coils are respectively connected with the first end of the third communication inductor and the first end of the fourth communication inductor. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When the common mode current flows through the common mode inductor, the common mode inductor can reduce the generated common mode current, thereby avoiding noise from influencing the normal operation of related equipment in the photovoltaic system and further improving the electromagnetic compatibility effect.
In one possible implementation manner, the third communication inductor and the fourth communication inductor are coupled on one magnetic core, winding directions of the third communication inductor and the fourth communication inductor are opposite and the winding directions are the same, the first end of the third communication inductor and the first end of the fourth communication inductor are same-name ends, and leakage inductance between the third communication inductor and the fourth communication inductor is larger than a set threshold value. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When the common mode current flows through the third communication inductor and the fourth communication inductor, the generated common mode current can be reduced by the third communication inductor and the fourth communication inductor, so that noise is prevented from influencing normal operation of related equipment in the photovoltaic system, and the electromagnetic compatibility effect is further improved. In addition, by using leakage inductance between the third communication inductance and the fourth communication inductance as the communication inductance in the power line carrier communication, the device cost is further saved.
In one possible implementation manner, the third communication inductor, the fourth communication inductor and the second communication transformer are coupled on one magnetic core, winding directions of the third communication inductor and the fourth communication inductor are opposite and the winding directions are the same, the first end of the third communication inductor and the first end of the fourth communication inductor are the same-name ends, and leakage inductance between the third communication inductor and the fourth communication inductor is larger than a set threshold value. The third communication inductance and the fourth communication inductance are used as primary windings of a second communication transformer, secondary windings of the second communication transformer are coupled to the magnetic core, and the transformation ratio of the second communication transformer changes along with the change of leakage inductance between the third communication inductance and the fourth communication inductance. The circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise. When the common-mode current flows through the third communication inductor and the fourth communication inductor, the generated common-mode current can be reduced by the third communication inductor and the fourth communication inductor, so that noise is prevented from influencing normal operation of related equipment in the photovoltaic system, and the electromagnetic compatibility effect is further improved. In addition, by using the leakage inductance between the third communication inductance and the fourth communication inductance as the communication inductance in the power line carrier communication, and using the third communication inductance and the fourth communication inductance as the primary winding of the second communication transformer, the device cost is further saved.
Drawings
Fig. 1 is a schematic view of an application scenario of a photovoltaic system provided in the present application;
FIG. 2 is a schematic diagram of differential mode noise generation provided herein;
FIG. 3 is a schematic view of a photovoltaic system provided herein;
FIG. 4 is another schematic structural view of the photovoltaic system provided herein;
FIG. 5 is a schematic view of a photovoltaic optimizer provided herein;
FIG. 6 is another schematic structural view of the photovoltaic optimizer provided herein;
FIG. 7 is another schematic structural view of the photovoltaic optimizer provided herein;
FIG. 8 is a schematic diagram of a communication inductive coupling provided herein;
FIG. 9 is another schematic structural view of the photovoltaic optimizer provided herein;
FIG. 10 is another structural schematic diagram of the communicative inductive coupling provided herein;
FIG. 11 is another schematic structural view of the photovoltaic optimizer provided herein;
fig. 12 is a schematic structural diagram of an inverter provided in the present application;
fig. 13 is another schematic structural view of the inverter provided herein;
fig. 14 is another schematic structural view of the inverter provided in the present application.
Detailed Description
Referring to fig. 1, fig. 1 is a schematic view of an application scenario of a photovoltaic system provided in the present application. The photovoltaic system can comprise a direct current power supply, a photovoltaic optimizer and an inverter, wherein the direct current power supply can be a photovoltaic array, the photovoltaic array is formed by connecting a plurality of photovoltaic modules in series or in parallel, the output end of the photovoltaic module can be connected with the input end of the photovoltaic optimizer, and the output end of the photovoltaic optimizer can be connected with the input end of the inverter. Alternatively, the photovoltaic system may include a plurality of photovoltaic optimizers, and the output ends of the photovoltaic optimizers may be connected in series and then connected to the input end of the inverter through a power line (not shown in fig. 1), where the output end of the inverter is connected to an ac load. The photovoltaic optimizer can track the maximum output power of the current photovoltaic module in real time by utilizing the maximum power point tracking (Maximum Power Point Tracking, MPPT) technology, and control the photovoltaic module to work at the maximum power point so as to improve the photoelectric conversion efficiency. The inverter can perform voltage inversion conversion on direct current output by the photovoltaic optimizer and then supply power for an alternating current load, and the alternating current load can be an alternating current power grid or alternating current electric equipment. Here, when the inverter is connected to the grid, the ac load may be an ac power grid, and when the inverter is disconnected from the grid, the ac load may be an ac electric device.
In the application scenario shown in fig. 1, data interaction (for example, mutually acquiring electrical quantities such as voltage and power information) can be performed between the photovoltaic optimizer and the inverter through power line carrier communication. Specifically, a PLC inductor may be connected in series to a negative pole branch of an output port of the photovoltaic optimizer, and a communication transformer (or a PLC signal transformer) may be connected in parallel to two ends of the PLC inductor. Taking the example that the photovoltaic optimizer receives the electrical quantity information sent by the inverter, a PLC inductor in the photovoltaic optimizer can receive a high-frequency modulation signal from the inverter through a power line, the PLC inductor forms partial pressure based on the received high-frequency voltage component, and the size of the partial pressure of the PLC inductor is positively correlated with the impedance of the PLC inductor. The high-frequency voltage component on the PLC inductor can be transformed through the communication transformer, and the controller can obtain electric quantity information from the inverter after demodulating based on the transformed high-frequency voltage component. However, since a PLC inductor is connected in series to the output end of the photovoltaic optimizer, the line impedance on the positive and negative lines of the output port of the photovoltaic optimizer is inconsistent, thereby generating differential mode noise during the operation of the photovoltaic optimizer. Similarly, a PLC inductor can be connected in series on the negative pole branch of the input port of the inverter, and the communication transformer is connected in parallel with the two ends of the PLC inductor to realize the power line carrier communication of the photovoltaic optimizer and the inverter, so that the line impedance on the positive and negative lines of the input port of the inverter is inconsistent, and the differential mode noise is generated in the working process of the inverter. Referring to fig. 2 together, fig. 2 is a schematic diagram of differential mode noise generation provided in the present application. As shown in fig. 2, taking a photovoltaic optimizer as an example, an output end of a voltage conversion circuit in the photovoltaic optimizer is connected in series with a PLC inductor L0, two ends of the PLC inductor L0 are connected in parallel with a communication transformer, and the PLC inductor L0 and the communication transformer can be used for power line carrier communication. The output end of the voltage conversion circuit can be connected with a line impedance stabilizing network (Line Impedance Stabilization Network, LISN), which is an important auxiliary device in electromagnetic compatibility test in the power system, and can be used for detecting common mode noise, differential mode noise and the like generated in the working process of the photovoltaic optimizer. The LISN may include a capacitor C1 and a resistor R1 connected in series, and a capacitor C2 and a resistor R2 connected in series, where the resistances of the resistor R1 and the resistor R2 are equal, and the resistor R1 and the resistor R2 are connected and the connection end is grounded through a resistor R3. When common mode noise is generated in the working process of the photovoltaic optimizer, common mode current Icm1 and common mode current Icm2 which are equal in current magnitude and same in direction can be detected on the resistor R1 and the resistor R2 respectively. Because one branch of the output end of the voltage conversion circuit is connected with the PLC inductor L0 in series, the impedance of the two branches of the output end of the voltage conversion circuit is different, so that differential mode noise appears in a loop formed by the voltage conversion circuit and the LISN in the photovoltaic optimizer, namely differential mode currents Idm flowing through the resistor R1 and the resistor R2 in different directions. It can be understood that when the inverter circuit in the inverter is connected to the PLC inductor and the communication transformer, the impedance of two branches at the input end of the inverter circuit is different, and differential mode noise occurs in a loop formed by the inverter circuit and the LISN. After the inductor and the transformer required by the power line carrier communication are added into the photovoltaic optimizer or the inverter, the line impedance of the positive and negative branches of the output port of the photovoltaic optimizer or the input port of the inverter is inconsistent, so that differential mode noise is generated in the working process of the photovoltaic optimizer or the inverter, and the generated differential mode noise cannot be effectively filtered, so that the differential mode noise exceeds the standard, and the electromagnetic compatibility effect is poor.
In the photovoltaic system provided by the application, the photovoltaic optimizer or the inverter can respectively comprise a communication device for power line carrier communication, and the communication device can comprise a first communication inductor, a second communication inductor and a communication transformer. Specifically, the first end of the first communication inductor and the first end of the second communication inductor may be respectively used to connect one end of the power conversion circuit, the second end of the first communication inductor and the second end of the second communication inductor are respectively connected with the communication transformer, the impedance of the first communication inductor and the impedance of the second communication inductor are equal, the power conversion circuit may be a voltage conversion circuit in the photovoltaic optimizer, or an inverter circuit in the inverter, and may be specifically determined according to the actual application scenario requirements, and the power conversion circuit is not limited herein. The first communication inductor and the second communication inductor can receive high-frequency modulation signals through the power line, the communication transformer can perform transformation based on high-frequency voltage components on the first communication inductor and the second communication inductor, and a controller in the communication device can obtain electric quantity information from other equipment communicating with the power conversion circuit after demodulation based on the transformed high-frequency voltage components. Here, since the impedances of the first communication inductor and the second communication inductor are equal, the line impedances on the positive and negative branches at one end of the power conversion circuit are equal, so that differential mode noise is avoided in the working process of the power conversion circuit. For example, the first end of the first communication inductor and the first end of the second communication inductor may be respectively used to connect the positive output end and the negative output end of the voltage conversion circuit in the photovoltaic optimizer, and the second end of the first communication inductor and the second end of the second communication inductor are respectively connected to the communication transformer, where the impedances of the first communication inductor and the second communication inductor are equal. In the working process of the photovoltaic optimizer, the circuit impedance on the positive electrode output end and the circuit impedance on the negative electrode output end of the voltage conversion circuit are equal, so that the common mode noise source of the photovoltaic optimizer is prevented from being converted into differential mode noise, the generated common mode current can be reduced by adding a common mode inductance and the like into the photovoltaic optimizer, the noise is prevented from affecting the normal operation of related equipment in a photovoltaic system, and the electromagnetic compatibility effect is further improved.
Referring to fig. 3, fig. 3 is a schematic structural diagram of a photovoltaic system provided in the present application, where the photovoltaic system shown in fig. 3 may include a dc power source, a photovoltaic optimizer, and an inverter, where the dc power source may be a photovoltaic array including a plurality of photovoltaic strings. The photovoltaic system can comprise a plurality of photovoltaic optimizers, and the output ends of the photovoltaic optimizers can be connected in series and then connected with the input end of the inverter through a power line. Taking the photovoltaic system as an example, the photovoltaic system comprises two photovoltaic optimizers (for convenience of description, the photovoltaic optimizers can be represented as a photovoltaic optimizer A and a photovoltaic optimizer B), the output ends of the photovoltaic module PV1 and the photovoltaic module PV2 can be respectively connected with the first ends of the photovoltaic optimizers A and B, the second ends of the photovoltaic optimizers A and B are connected in series and then are connected with the input end of the inverter, and the output end of the inverter is connected with an alternating current load. The photovoltaic optimizers A and B can track the maximum output power of the current photovoltaic module PV1 and PV2 respectively by using a maximum power point tracking technology, and control the photovoltaic modules PV1 and PV2 to work at the maximum power points so as to improve the photoelectric conversion efficiency, and the inverter can supply power to an alternating current load after performing voltage inversion conversion on the direct current output by the photovoltaic optimizers.
In some possible embodiments, in the photovoltaic system shown in fig. 3, the photovoltaic optimizer may include a voltage conversion circuit, a first communication inductance, a second communication inductance, and a communication transformer. Taking the photovoltaic optimizer a as an example, an input end of a voltage conversion circuit in the photovoltaic optimizer a may be used to connect with the photovoltaic module PV1, a first end of a first communication inductor and a first end of a second communication inductor are respectively connected with an anode output end and a cathode output end of the voltage conversion circuit, and a second end of the first communication inductor and a second end of the second communication inductor are respectively connected with an anode input end and a cathode input end of the inverter through power lines. The second end of the first communication inductance and the second end of the second communication inductance are also respectively connected with the communication transformer (can be a primary winding of the communication transformer), and the impedance of the first communication inductance and the impedance of the second communication inductance are equal. The photovoltaic optimizer may further include a controller connected to a communication transformer (may be a secondary winding of the communication transformer), the first communication inductor and the second communication inductor may receive the high-frequency modulation signal from the inverter through the power line, the communication transformer may perform transformation based on the high-frequency voltage components on the first communication inductor and the second communication inductor, and the controller may obtain electrical quantity information from the inverter after demodulating based on the transformed high-frequency voltage components. Alternatively, the controller may modulate and generate the second high-frequency voltage component based on the electrical quantity information of the voltage conversion circuit in the photovoltaic optimizer, transform the second high-frequency voltage component based on the second high-frequency voltage component through the communication transformer, and output the transformed second high-frequency voltage component to the power line to transmit the electrical quantity information of the voltage conversion circuit to the inverter.
In the working process of the photovoltaic optimizer A, the circuit impedance of the positive electrode output end and the circuit impedance of the negative electrode output end of the voltage conversion circuit are equal, so that the conversion of a common-mode noise source of the photovoltaic optimizer A into differential-mode noise is avoided, the generated common-mode current can be reduced by adding a common-mode inductor into the photovoltaic optimizer A, the noise is prevented from influencing the normal operation of related equipment in a photovoltaic system, and the electromagnetic compatibility effect is further improved.
In some possible embodiments, the inverter in the photovoltaic system described above may include a first communication inductance, a second communication inductance, and a communication transformer for power line carrier communication. Referring to fig. 4, fig. 4 is another schematic structural diagram of the photovoltaic system provided in the present application, where the photovoltaic system shown in fig. 4 may include a dc power source, a photovoltaic optimizer, and an inverter, where the dc power source may be a photovoltaic array including a plurality of photovoltaic strings. The photovoltaic system can comprise a plurality of photovoltaic optimizers, and the output ends of the photovoltaic optimizers can be connected in series and then connected with the input end of the inverter through a power line. Taking the photovoltaic system as an example, the photovoltaic system comprises two photovoltaic optimizers (for convenience of description, the photovoltaic optimizers can be represented as a photovoltaic optimizer A and a photovoltaic optimizer B), the output ends of the photovoltaic module PV1 and the photovoltaic module PV2 can be respectively connected with the first ends of the photovoltaic optimizers A and B, the second ends of the photovoltaic optimizers A and B are respectively connected with the input ends of the inverter, and the output ends of the inverter are connected with the alternating current load. In the photovoltaic system shown in fig. 4, the inverter may include an inverter circuit, a first communication inductance, a second communication inductance, and a communication transformer. The output end of the inverter circuit can be used for being connected with an alternating current load, the first end of the first communication inductor and the first end of the second communication inductor can be respectively connected with the positive electrode input end and the negative electrode input end of the inverter circuit, and the second end of the first communication inductor and the second end of the second communication inductor can be respectively connected with the positive electrode output end and the negative electrode output end of the photovoltaic optimizer through power lines. The second end of the first communication inductor and the second end of the second communication inductor can be respectively connected with a communication transformer, the communication transformer can output voltage signals after transforming based on the voltages on the first communication inductor and the second communication inductor, and the impedance of the first communication inductor is equal to the impedance of the second communication inductor. The inverter may further include a controller connected to a communication transformer (may be a secondary winding of the communication transformer), where the first communication inductor and the second communication inductor may receive the high-frequency modulation signal from the photovoltaic optimizer through the power line, the communication transformer may perform transformation based on high-frequency voltage components on the first communication inductor and the second communication inductor, and the controller may obtain electrical quantity information from the photovoltaic optimizer after demodulating based on the transformed high-frequency voltage components. Alternatively, the controller may modulate and generate the second high-frequency voltage component based on the electrical quantity information of the inverter circuit in the inverter, transform the second high-frequency voltage component based on the second high-frequency voltage component through the communication transformer, and output the transformed second high-frequency voltage component to the power line to transmit the electrical quantity information of the inverter circuit to the light Fu Qi. In the working process of the inverter, the circuit impedance of the positive electrode output end and the circuit impedance of the negative electrode output end of the inverter circuit are equal, the common mode noise source of the inverter is prevented from being converted into differential mode noise, the generated common mode current can be reduced by adding common mode inductance and the like into the inverter, the noise is prevented from affecting the normal operation of related equipment in a photovoltaic system, and the electromagnetic compatibility effect is further improved.
The photovoltaic optimizers and inverters provided in the embodiments of the present application will be exemplified below with reference to fig. 5 to 13. In some possible embodiments, the photovoltaic optimizer includes a common-mode inductor, and the magnetic core of the common-mode inductor may include two coils with opposite directions and the same number of turns, where one ends of the two coils are respectively connected to the positive output end and the negative output end of the voltage conversion circuit, and the other ends of the two coils are respectively connected to the first end of the first communication inductor and the first end of the second communication inductor. Specifically, the voltage conversion circuit may be a BUCK circuit, and the voltage conversion circuit includes an input capacitor and an output capacitor, where two ends of the input capacitor may be used to connect to a photovoltaic module, and two ends of the output capacitor may be used to couple to the first communication inductor and the second communication inductor. The voltage conversion circuit further comprises a first switching tube and a second switching tube, the first switching tube and the second switching tube can be connected in parallel to two ends of the input capacitor after being connected in series, the connecting end of the first switching tube and the connecting end of the second switching tube are connected with one end of the output capacitor through an inductor, and the other end of the output capacitor is connected with the connecting end of the second switching tube and the input capacitor. Referring to fig. 5, fig. 5 is a schematic structural diagram of a photovoltaic optimizer provided in the present application, in the photovoltaic optimizer shown in fig. 5, a voltage conversion circuit of the photovoltaic optimizer includes a capacitor C in Capacitance C in One end of the switch tube Q1 and one end of the switch tube Q2 pass through the inductor L buck One end of the switch tube Q2 is connected with the capacitor C in Is connected to the other end of the inductor L buck Through capacitor C buck And is connected to the other end of the switching tube Q2. The photovoltaic optimizer shown in fig. 5 includes a common-mode inductor T1, and the core of the common-mode inductor T1 may include two coils with opposite directions and the same number of turns, in other words, a common coilThe coil on the magnetic core of the die inductor T1 is connected with the same-name end. One end of the two coils of the common-mode inductor T1 is respectively connected with a capacitor C in the voltage conversion circuit buck The other ends of the two coils of the common-mode inductor T1 are respectively connected with the first end of a first communication inductor (which can be expressed as an inductor L1 for convenience of description) and the first end of a second communication inductor (which can be expressed as an inductor L2 for convenience of description), and a capacitor C o Is connected between the common-mode inductor T1 and the inductors L1 and L2. The second end of the inductor L1 and the second end of the inductor L2 are respectively connected with the primary winding of the communication transformer, and the impedance of the inductor L1 and the impedance of the inductor L2 are equal. The switching transistors in the photovoltaic optimizer may be Metal-Oxide-semiconductor field effect transistors (MOSFETs), abbreviated as MOS transistors, or may be insulated gate bipolar transistors (insulated gate bipolar transistor, IGBTs), and the like, which are not limited herein. Here, in the working process of the photovoltaic optimizer, common mode currents with equal current and identical direction can flow through the inductor L1 and the inductor L2, and the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise due to the fact that the circuit impedance of the positive electrode output end and the circuit impedance of the negative electrode output end of the voltage conversion circuit are equal. When the common-mode current flows through the common-mode inductor T1, the common-mode inductor T1 can reduce the generated common-mode current, thereby avoiding noise from influencing the normal operation of related equipment in the photovoltaic system and further improving the electromagnetic compatibility effect. Specifically, when the positive output terminal and the negative output terminal of the voltage conversion circuit in the photovoltaic optimizer are connected to the LISN (see LISN shown in fig. 2 above), the common mode current on the resistor R1 and the resistor R2 in the LISN is smaller than the set threshold value because the common mode inductance T1 can reduce the generated common mode current. In addition, since the line impedances at the positive output end and the negative output end of the voltage conversion circuit are equal, differential mode currents with opposite directions can not appear at the resistor R1 and the resistor R2. The inductor L1 and the inductor L2 may receive the high-frequency modulation signal from the inverter through the power line, the communication transformer may perform transformation based on the high-frequency voltage components on the inductor L1 and the inductor L2, and a controller (not shown in fig. 5) connected to the secondary winding of the communication transformer may perform demodulation based on the transformed high-frequency voltage components Electrical quantity information from the inverter is obtained. Or, the controller can modulate and generate a second high-frequency voltage component based on the electrical quantity information of the voltage conversion circuit in the photovoltaic optimizer, and output the second high-frequency voltage component to the power line to transmit the electrical quantity information of the voltage conversion circuit to the inverter after transforming the second high-frequency voltage component through the communication transformer, so that the power line carrier communication between the photovoltaic optimizer and other equipment is realized, and meanwhile, the electromagnetic compatibility effect is guaranteed.
In some possible embodiments, the common mode current in the photovoltaic optimizer shown in fig. 5 may be generated by the action of a switching tube in the voltage conversion circuit, please refer to fig. 6, fig. 6 is another schematic structural diagram of the photovoltaic optimizer provided in the present application, and in the photovoltaic optimizer shown in fig. 6, the voltage conversion circuit included in the photovoltaic optimizer is similar to the photovoltaic optimizer shown in fig. 5. Here, since the switching transistor Q1 and the switching transistor Q2 are periodically turned on or off, a periodic voltage change occurs at the connection point of the switching transistor Q1 and the switching transistor Q2. Specifically, the switching tube Q1 and the switching tube Q2 may be complementarily turned on, when the switching tube Q1 is turned on and the switching tube Q2 is turned off, the voltage of the junction point of the switching tube is the input voltage Vin of the photovoltaic optimizer, and when the switching tube Q1 is turned off and the switching tube Q2 is turned on, the voltage of the junction point of the switching tube is zero. In practical product applications, the voltage conversion circuit is integrated in the power module, so that an equivalent parasitic capacitance Cg is formed between the housing of the power module and the housing of the heat dissipation module of the power module, and the housing of the heat dissipation module of the power module is usually grounded, and the switching tube Q1 and the switching tube Q2 are alternately conducted to cause potential change, so that the parasitic capacitance Cg continuously charges and discharges, and an alternating current between the power module and the heat dissipation module, that is, a common mode current Icm, is equivalent. When the positive output terminal and the negative output terminal of the voltage conversion circuit in the photovoltaic optimizer are connected with the LISN (see LISN shown in fig. 2 above), the common mode current Icm may sequentially pass through the heat sink and the grounded casing due to the grounding of the LISN, so that the common mode current Icm flows into the LISN through the grounding terminal of the LISN, and then appears at the junction of the LISN and the voltage conversion circuit. When the common mode current Icm is generated in the working process of the photovoltaic optimizer, the common mode current Icm1 and the common mode current Icm2 with the same current magnitude and the same direction can be detected on the resistor R1 and the resistor R2 in the LISN respectively, and the common mode current Icm1 and the common mode current Icm2 can flow to the inductor L1 and the inductor L2 in the photovoltaic optimizer respectively. It can be understood that, before passing through the common-mode inductor T1, if the circuit structure is a symmetrical structure, the common-mode current Icm1 and the common-mode current Icm2 flow through the same impedance, and the current is equal; if the circuit structure is an asymmetric structure before passing through the common-mode inductor T1, the common-mode current Icm1 and the common-mode current Icm2 have different impedances, and the current levels are not equal, and the common-mode signal Icm becomes a differential-mode signal.
In some possible embodiments, the first communication inductor and the second communication inductor in the photovoltaic optimizer are coupled on one magnetic core, winding directions of the first communication inductor and the second communication inductor are opposite and the winding directions of the first communication inductor and the second communication inductor are the same, the first end of the first communication inductor and the first end of the second communication inductor are the same-name ends, and leakage inductance between the first communication inductor and the second communication inductor is larger than a set threshold value. Referring to fig. 7, fig. 7 is another schematic structural diagram of the photovoltaic optimizer provided in the present application, in the photovoltaic optimizer shown in fig. 7, the photovoltaic optimizer includes a voltage conversion circuit, and the circuit structure of the voltage conversion circuit may be referred to the photovoltaic optimizer described in fig. 5 above, which is not described herein again. In the photovoltaic optimizer, an inductor L1 and an inductor L2 are coupled on one magnetic core, the winding directions of the inductor L1 and the inductor L2 are opposite and the number of turns is the same, namely the first end of the inductor L1 and the first end of the inductor L2 are the same-name ends. The second end of the inductor L1 and the second end of the inductor L2 are respectively connected with the primary winding of the communication transformer, and the impedance of the inductor L1 and the impedance of the inductor L2 are equal. Here, in the working process of the photovoltaic optimizer, common mode currents with equal current and identical direction can flow through the inductor L1 and the inductor L2, and the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise due to the fact that the circuit impedance of the positive electrode output end and the circuit impedance of the negative electrode output end of the voltage conversion circuit are equal. The photovoltaic optimizer may include a filter inductor, which may be connected between the positive output end of the voltage conversion circuit and the first communication inductor, specifically, as shown in fig. 7, one end of the inductor L3 in the photovoltaic optimizer may be connected to the inductor L buck And capacitor C buck The other end of the inductor L3 can be connected with a capacitor C o The inductor L3 can be used for reducing the differential mode noise generated by the voltage conversion circuit in the photovoltaic optimizer. Further, in the inductance L1 and the inductance L2 coupled in one magnetic core, common mode components Lcm1 and Lcm2, and differential mode components Ldm1 and Ldm2 may be included. Here, the differential mode component may also be referred to as leakage inductance between the inductor L1 and the inductor L2, which is an inductance component generated by incomplete coupling of the magnetic fluxes of the inductor L1 to the inductor L2, and the uncoupled portion of the magnetic fluxes may be represented as a series inductive impedance. When the common-mode current flows through the inductor L1 and the inductor L2, the generated common-mode current can be reduced by the inductor L1 and the inductor L2, the effect of reducing the common-mode current depends on the magnitudes of the common-mode components Lcm1 and Lcm2, and therefore noise is prevented from affecting the normal operation of related equipment in a photovoltaic system, and the electromagnetic compatibility effect is further improved. The common mode current on the inductor L1 and the inductor L2 may be generated due to the switching operation of the switching tube in the voltage conversion circuit, and the specific generation process may refer to the description in fig. 6, which is not repeated herein. The leakage inductance between the above-mentioned inductance L1 and inductance L2, that is, the inductance value of the differential mode components Ldm and Ldm is greater than the set threshold value, the inductance L1 and inductance L2 may receive the high-frequency modulation signal from the inverter through the power line, the above-mentioned communication transformer may perform transformation based on the high-frequency voltage components on the inductance L1 and inductance L2, and the controller (not shown in fig. 7) connected to the secondary winding of the communication transformer may obtain the electrical quantity information from the inverter after demodulating based on the transformed high-frequency voltage components. Or, the controller can modulate and generate a second high-frequency voltage component based on the electrical quantity information of the voltage conversion circuit in the photovoltaic optimizer, and output the second high-frequency voltage component to the power line to transmit the electrical quantity information of the voltage conversion circuit to the inverter after transforming the second high-frequency voltage component through the communication transformer, so that the power line carrier communication between the photovoltaic optimizer and other equipment is realized, and meanwhile, the electromagnetic compatibility effect is guaranteed. In addition, by using leakage inductance between the inductance L1 and the inductance L2 as a communication inductance in power line carrier communication, device cost is further saved. Please refer to fig. 8, fig. 8 is a diagram of the present application Please provide a schematic diagram of the communication inductance coupling structure. As shown in fig. 8, the magnetic core in fig. 8 may be a closed rectangle, the windings of the inductor L1 and the inductor L2 are wound on two opposite sides of the magnetic core (may be wound on upper ends and lower ends of the two opposite sides), and winding directions of the inductor L1 and the inductor L2 are opposite. Here, the start ends of the two coil windings are the same name ends (such as the A1 end of the inductor L1 and the B1 end of the inductor L2), and the end ends of the two coil windings are also the same name ends (such as the A2 end of the inductor L1 and the B2 end of the inductor L2). Taking the power converter in the power grid supply system shown in fig. 7 as an example, in the communication inductor shown in fig. 8, the A1 end of the inductor L1 may be connected to the positive output end of the voltage conversion circuit, the A2 end of the inductor L1 may be used to connect to the positive input end of the inverter, the B1 end of the inductor L2 may be connected to the negative output end of the voltage conversion circuit, and the B2 end of the inductor L2 may be used to connect to the negative input end of the inverter. In addition, rectangular protrusions with adjustable length can be arranged on two sides of the magnetic core without winding, and the rectangular protrusions can be used for eliminating differential mode noise generated by a voltage conversion circuit.
In some possible embodiments, the first communication inductor, the second communication inductor and the communication transformer in the photovoltaic optimizer are coupled on one magnetic core, winding directions of the first communication inductor and the second communication inductor are opposite and the number of turns is the same, a first end of the first communication inductor and a first end of the second communication inductor are same-name ends, and leakage inductance between the first communication inductor and the second communication inductor is larger than a set threshold value. Referring to fig. 9, fig. 9 is another schematic structural diagram of the photovoltaic optimizer provided in the present application, in the photovoltaic optimizer shown in fig. 9, the photovoltaic optimizer includes a voltage conversion circuit, and the circuit structure of the voltage conversion circuit may be referred to the photovoltaic optimizer described in fig. 5 above, which is not described herein again. In the photovoltaic optimizer, an inductor L1 and an inductor L2 are coupled on one magnetic core, winding directions of the inductor L1 and the inductor L2 are opposite and the winding directions are the same, namely a first end of the inductor L1 and a first end of the inductor L2 are same-name ends, and impedance of the inductor L1 and impedance of the inductor L2 are equal. The secondary winding of the communication transformer is coupled to the magnetic core, and the inductance L1 and the inductance L2 can be used as the primary winding of the communication transformer, in other words, the transformation of the communication transformer The ratio may vary as the leakage inductance between the inductance L1 and the inductance L2 varies. Here, in the working process of the photovoltaic optimizer, common mode currents with equal current and identical direction can flow through the inductor L1 and the inductor L2, and the common mode noise source of the photovoltaic optimizer can be prevented from being converted into differential mode noise due to the fact that the circuit impedance of the positive electrode output end and the circuit impedance of the negative electrode output end of the voltage conversion circuit are equal. The common mode current on the inductor L1 and the inductor L2 may be generated due to the switching operation of the switching tube in the voltage conversion circuit, and the specific generation process may refer to the description in fig. 6, which is not repeated herein. The photovoltaic optimizer may include a filter inductor, which may be connected between the positive output end of the voltage conversion circuit and the first communication inductor, specifically, as shown in fig. 9, one end of the inductor L3 in the photovoltaic optimizer may be connected to the inductor L buck And capacitor C buck The other end of the inductor L3 can be connected with a capacitor C o The inductor L3 can be used for reducing the differential mode noise generated by the voltage conversion circuit in the photovoltaic optimizer. Further, in the inductance L1 and the inductance L2 coupled in one magnetic core, common mode components Lcm1 and Lcm2, and differential mode components Ldm1 and Ldm2 may be included. Here, the differential mode component may also be referred to as leakage inductance between the inductor L1 and the inductor L2, which is an inductance component generated by incomplete coupling of the magnetic fluxes of the inductor L1 to the inductor L2, and the uncoupled portion of the magnetic fluxes may be represented as a series inductive impedance. When the common-mode current flows through the inductor L1 and the inductor L2, the generated common-mode current can be reduced by the inductor L1 and the inductor L2, the effect of reducing the common-mode current depends on the magnitudes of the common-mode components Lcm1 and Lcm2, and therefore noise is prevented from affecting the normal operation of related equipment in a photovoltaic system, and the electromagnetic compatibility effect is further improved. Leakage inductance between the inductor L1 and the inductor L2, that is, inductance values of differential mode components Ldm and Ldm are larger than a set threshold, the inductor L1 and the inductor L2 can receive high-frequency modulation signals from an inverter through a power line, the communication transformer can perform transformation based on high-frequency voltage components on the inductor L1 and the inductor L2, and a controller (not shown in fig. 9) connected with a secondary winding of the communication transformer can obtain signals from the inverter after demodulation based on the transformed high-frequency voltage components And electrical quantity information of the device. Or, the controller can modulate and generate a second high-frequency voltage component based on the electrical quantity information of the voltage conversion circuit in the photovoltaic optimizer, and output the second high-frequency voltage component to the power line to transmit the electrical quantity information of the voltage conversion circuit to the inverter after transforming the second high-frequency voltage component through the communication transformer, so that the power line carrier communication between the photovoltaic optimizer and other equipment is realized, and meanwhile, the electromagnetic compatibility effect is guaranteed. In addition, by using leakage inductance between the inductor L1 and the inductor L2 as communication inductance in power line carrier communication, and using the inductor L1 and the inductor L2 as primary windings of a communication transformer, device cost is further saved. Referring to fig. 10 together, fig. 10 is a schematic diagram of another structure of the communication inductive coupling provided in the present application. As shown in fig. 10, the magnetic core in fig. 10 may be a closed rectangle, the windings of the inductor L1 and the inductor L2 are wound on two opposite sides of the magnetic core (may be wound on upper ends and lower ends of the two opposite sides), and winding directions of the inductor L1 and the inductor L2 are opposite. Here, the start ends of the two coil windings are the same name ends (such as the A1 end of the inductor L1 and the B1 end of the inductor L2), and the end ends of the two coil windings are also the same name ends (such as the A2 end of the inductor L1 and the B2 end of the inductor L2). Taking the power converter in the power grid supply system shown in fig. 9 as an example, in the communication inductor shown in fig. 10, the A1 end of the inductor L1 may be connected to the positive output end of the voltage conversion circuit, the A2 end of the inductor L1 may be used to connect to the positive input end of the inverter, the B1 end of the inductor L2 may be connected to the negative output end of the voltage conversion circuit, and the B2 end of the inductor L2 may be used to connect to the negative input end of the inverter. The magnetic core shown in fig. 10 further comprises a winding M1, wherein the winding M1 can be wound on a rectangular protrusion on one side of the magnetic core, and the winding M1 can be used as a secondary winding of the communication transformer.
In some possible embodiments, the voltage conversion circuit may be a BUCK-BOOST circuit, see fig. 11, and fig. 11 is another schematic structural diagram of the photovoltaic optimizer provided in the present application. In the photovoltaic optimizer shown in fig. 11, the voltage conversion circuit of the photovoltaic optimizer includes a capacitor C in And capacitor C out The switch tube Q1 and the switch tube Q2 are connected in series and then connected in parallel with the capacitor C in Two ends, a switching tube Q3 and a switching tube Q4 are connected in series and then connected in parallel with a capacitor C out The two ends, the connection ends of the switch tube Q1 and the switch tube Q2 are connected with the connection ends of the switch tube Q3 and the switch tube Q4 through an inductor L4, and a capacitor C in A connection end of the switch tube Q2 and a capacitor C out Is connected with the connecting end of the switching tube Q4. The photovoltaic optimizer shown in fig. 11 includes a common-mode inductor T1, and one ends of two coils of the common-mode inductor T1 are respectively connected with a capacitor C in the voltage conversion circuit out The other ends of the two coils of the common-mode inductor T1 are respectively connected with the first end of a first communication inductor (which can be expressed as an inductor L1 for convenience of description) and the first end of a second communication inductor (which can be expressed as an inductor L2 for convenience of description), and a capacitor C o Is connected between the common-mode inductor T1 and the inductors L1 and L2. The second end of the inductor L1 and the second end of the inductor L2 are respectively connected with the primary winding of the communication transformer, and the impedance of the inductor L1 and the impedance of the inductor L2 are equal. It can be appreciated that when the voltage conversion circuit is a BUCK-BOOST circuit, the first communication inductor and the second communication inductor in the photovoltaic optimizer may also be coupled to a magnetic core, and the specific coupling manner may refer to the photovoltaic optimizer shown in fig. 7 to 10, which is not described herein.
In some possible embodiments, the inverter includes a common-mode inductor, and the magnetic core of the common-mode inductor may include two coils with opposite directions and the same number of turns, one ends of the two coils are respectively connected to the positive output end and the negative output end of the voltage conversion circuit, and the other ends of the two coils are respectively connected to the first end of the first communication inductor and the first end of the second communication inductor. Referring to fig. 12, fig. 12 is a schematic structural diagram of an inverter provided in the present application. In the inverter shown in fig. 12, the inverter includes an inverter circuit, or the inverter may include a dc conversion circuit and an inverter circuit, and an output terminal of the dc conversion is connected to an input terminal of the inverter circuit, and the inverter is described here as including only the inverter circuit. The inverter circuit can comprise a capacitor C1, a capacitor C2 and 3 bridge arms (a bridge arm a, a bridge arm b and a bridge arm C), wherein the bridge arm a, the bridge arm b and the bridge arm C are ABC three-phase bridge arms respectively. The bridge arm a, the bridge arm b and the bridge arm C are connected in parallel at two ends of the capacitor C1 and the capacitor C2 which are connected in series, and the ports corresponding to the ABC three phases are respectively led out. Bridge arm a may include two first bridge arm switching tubes and second bridge arm switching tubes (for convenience of description, may be represented as switching tube Q11 and switching tube Q12), the switching tube Q11 and the switching tube Q12 may be connected in parallel to two ends of capacitor C1 and capacitor C2 connected in series in the power converter, a connection end of the switching tube Q11 and the switching tube Q12 may lead out an a-phase port, and a connection end of the switching tube Q11 and the switching tube Q12 may be connected to a series connection point of capacitor C1 and capacitor C2 through a third bridge arm switching tube and a fourth bridge arm switching tube (for convenience of description, may be represented as switching tube Q13 and switching tube Q14) connected in series. Bridge arm b may include a switching tube Q21, a switching tube Q22, a switching tube Q23, and a switching tube Q24, and bridge arm c may include a switching tube Q31, a switching tube Q32, a switching tube Q33, and a switching tube Q34, and it can be understood that in the inverter shown in fig. 12, the circuit structures of bridge arm b and bridge arm c are the same as those of the above-mentioned bridge arm a, and will not be repeated here. In the inverter shown in fig. 12, the inverter may include a common-mode inductor T1, and two coils having opposite directions and the same number of turns may be included on a core of the common-mode inductor T1, in other words, coils on the core of the common-mode inductor T1 are connected at the same name end. One end of each of the two coils of the common-mode inductor T1 is connected to two ends of the capacitor C1 and the capacitor C2 which are connected in series, and the other ends of the two coils of the common-mode inductor T1 are respectively connected with the first end of the first communication inductor (which can be expressed as an inductor L1 for convenience of description) and the first end of the second communication inductor (which can be expressed as an inductor L2 for convenience of description). The second end of the inductor L1 and the second end of the inductor L2 are respectively connected with the primary winding of the communication transformer, and the impedance of the inductor L1 and the impedance of the inductor L2 are equal. Each switching tube in the inverter may be a MOS tube, an IGBT tube, or the like, and is not limited herein. Here, during the working process of the inverter, common mode currents with equal current magnitude and same direction can flow through the inductor L1 and the inductor L2, and the circuit impedance on the positive output end and the negative output end of the voltage conversion circuit is equal, so that the conversion of the common mode noise source of the inverter into differential mode noise can be avoided. When the common-mode current flows through the common-mode inductor T1, the common-mode inductor T1 can reduce the generated common-mode current, thereby avoiding noise from influencing the normal operation of related equipment in the photovoltaic system and further improving the electromagnetic compatibility effect. The inductor L1 and the inductor L2 may receive the high-frequency modulation signal from the inverter through the power line, the communication transformer may perform transformation based on the high-frequency voltage components on the inductor L1 and the inductor L2, and a controller (not shown in fig. 12) connected to the secondary winding of the communication transformer may obtain electrical quantity information from the photovoltaic optimizer after demodulating based on the transformed high-frequency voltage components. Or, the controller can modulate and generate a second high-frequency voltage component based on the electrical quantity information of the inverter circuit in the inverter, and output the second high-frequency voltage component to the power line after transformation based on the second high-frequency voltage component through the communication transformer so as to transmit the electrical quantity information of the inverter circuit to the photovoltaic optimizer, thereby realizing power line carrier communication between the inverter and other equipment and ensuring the electromagnetic compatibility effect.
In some possible embodiments, referring to fig. 13, fig. 13 is another schematic structural diagram of an inverter provided in the present application, and in the inverter shown in fig. 13, the inverter includes an inverter circuit, and a circuit structure of the inverter circuit may be referred to the inverter described in fig. 12, which is not described herein. In the inverter, an inductor L1 and an inductor L2 are coupled on one magnetic core, the winding directions of the inductor L1 and the inductor L2 are opposite and the number of turns is the same, namely the first end of the inductor L1 and the first end of the inductor L2 are the same-name ends. The second end of the inductor L1 and the second end of the inductor L2 are respectively connected with the primary winding of the communication transformer, and the impedance of the inductor L1 and the impedance of the inductor L2 are equal. Here, during the working process of the inverter, common mode currents with equal current magnitude and same direction can flow through the inductor L1 and the inductor L2, and the common mode noise source of the inverter can be prevented from being converted into differential mode noise due to the fact that the line impedance of the positive input end and the line impedance of the negative input end of the inverter circuit are equal. The inverter may include a filter inductor, which may be connected between the positive input terminal of the inverter circuit and the first communication inductor, and the filter inductor may be used to reduce differential mode noise generated by the inverter circuit in the inverter. Further, in the inductance L1 and the inductance L2 coupled in one magnetic core, common mode components Lcm1 and Lcm2, and differential mode components Ldm1 and Ldm2 may be included. Here, the differential mode component may also be referred to as leakage inductance between the inductor L1 and the inductor L2, which is an inductance component generated by incomplete coupling of the magnetic fluxes of the inductor L1 to the inductor L2, and the uncoupled portion of the magnetic fluxes may be represented as a series inductive impedance. When the common-mode current flows through the inductor L1 and the inductor L2, the generated common-mode current can be reduced by the inductor L1 and the inductor L2, the effect of reducing the common-mode current depends on the magnitudes of the common-mode components Lcm1 and Lcm2, and therefore noise is prevented from affecting the normal operation of related equipment in a photovoltaic system, and the electromagnetic compatibility effect is further improved. The leakage inductance between the above-described inductance L1 and inductance L2, that is, the inductance values of the differential mode components Ldm and Ldm are greater than the set threshold value. The inductor L1 and the inductor L2 may receive the high-frequency modulation signal from the inverter through the power line, the communication transformer may perform transformation based on the high-frequency voltage components on the inductor L1 and the inductor L2, and a controller (not shown in fig. 13) connected to the secondary winding of the communication transformer may obtain electrical quantity information from the photovoltaic optimizer after demodulating based on the transformed high-frequency voltage components. Or, the controller can modulate and generate a second high-frequency voltage component based on the electrical quantity information of the inverter circuit in the inverter, and output the second high-frequency voltage component to the power line after transformation based on the second high-frequency voltage component through the communication transformer so as to transmit the electrical quantity information of the inverter circuit to the photovoltaic optimizer, thereby realizing power line carrier communication between the inverter and other equipment and ensuring the electromagnetic compatibility effect. In addition, by using leakage inductance between the inductance L1 and the inductance L2 as a communication inductance in power line carrier communication, device cost is further saved.
In some possible embodiments, referring to fig. 14, fig. 14 is another schematic structural diagram of an inverter provided in the present application, and in the inverter shown in fig. 14, the inverter includes an inverter circuit, and a circuit structure of the inverter circuit may be referred to the inverter described in fig. 14, which is not described herein. In the inverter, an inductor L1 and an inductor L2 are coupled on one magnetic core, winding directions of the inductor L1 and the inductor L2 are opposite and the number of turns is the same, namely a first end of the inductor L1 and a first end of the inductor L2 are same-name ends, and impedance of the inductor L1 and impedance of the inductor L2 are equal. The secondary winding of the communication transformer is coupled to the magnetic core, and the inductance L1 and the inductance L2 may serve as primary windings of the communication transformer, in other words, a transformation ratio of the communication transformer may be changed with a change in leakage inductance between the inductance L1 and the inductance L2. Here, during the working process of the inverter, common mode currents with equal current magnitude and same direction can flow through the inductor L1 and the inductor L2, and the common mode noise source of the inverter can be prevented from being converted into differential mode noise due to the fact that the line impedance of the positive input end and the line impedance of the negative input end of the inverter circuit are equal. The inverter may include a filter inductor, which may be connected between the positive input terminal of the inverter circuit and the first communication inductor, and the filter inductor may be used to reduce differential mode noise generated by the inverter circuit in the inverter. Further, in the inductance L1 and the inductance L2 coupled in one magnetic core, common mode components Lcm1 and Lcm2, and differential mode components Ldm1 and Ldm2 may be included. When the common-mode current flows through the inductor L1 and the inductor L2, the generated common-mode current can be reduced by the inductor L1 and the inductor L2, the effect of reducing the common-mode current depends on the magnitudes of the common-mode components Lcm1 and Lcm2, and therefore noise is prevented from affecting the normal operation of related equipment in a photovoltaic system, and the electromagnetic compatibility effect is further improved. The leakage inductance between the above-described inductance L1 and inductance L2, that is, the inductance values of the differential mode components Ldm and Ldm are greater than the set threshold value. The inductor L1 and the inductor L2 may receive the high-frequency modulation signal from the inverter through the power line, the communication transformer may perform transformation based on the high-frequency voltage components on the inductor L1 and the inductor L2, and a controller (not shown in fig. 14) connected to the secondary winding of the communication transformer may obtain electrical quantity information from the photovoltaic optimizer after demodulating based on the transformed high-frequency voltage components. Or, the controller can modulate and generate a second high-frequency voltage component based on the electrical quantity information of the inverter circuit in the inverter, and output the second high-frequency voltage component to the power line after transformation based on the second high-frequency voltage component through the communication transformer so as to transmit the electrical quantity information of the inverter circuit to the photovoltaic optimizer, thereby realizing power line carrier communication between the inverter and other equipment and ensuring the electromagnetic compatibility effect. In addition, by using leakage inductance between the inductor L1 and the inductor L2 as communication inductance in power line carrier communication, and using the inductor L1 and the inductor L2 as primary windings of a communication transformer, device cost is further saved.
In some possible embodiments, the bridge arm a in the inverter may include four bridge arm switching tubes (for convenience of description, may be represented as a switching tube Q11, a switching tube Q12, a switching tube Q13, and a switching tube Q14), where the switching tube Q11, the switching tube Q12, the switching tube Q13, and the switching tube Q14 are sequentially connected in series and in parallel at two ends of the capacitor C1 and the capacitor C2, the connection ends of the switching tube Q11 and the switching tube Q12 are connected to the connection ends of the switching tube Q13 and the switching tube Q14 through two diodes connected in series, the connection ends of the two diodes connected in series are connected to a neutral point, and the connection ends of the switching tube Q12 and the switching tube Q13 may lead out of the phase a port. The circuit structures of the bridge arm b and the bridge arm c are the same as those of the bridge arm a, and are not repeated here.
In some possible embodiments, the bridge arm a in the inverter may include four bridge arm switching tubes (for convenience of description, may be represented by a switching tube Q11, a switching tube Q12, a switching tube Q13, and a switching tube Q14) connected in series, where the switching tube Q11, the switching tube Q12, the switching tube Q13, and the switching tube Q14 are sequentially connected in series and in parallel at two ends of the capacitor C1 and the capacitor C2, the connection ends of the switching tube Q11 and the switching tube Q12 are connected to the connection ends of the switching tube Q13 and the switching tube Q14 through two switching tubes (switching tube Q15 and switching tube Q16) connected in series, the connection ends of the switching tube Q15 and the switching tube Q16 are connected to a neutral point, and the connection ends of the switching tube Q12 and the switching tube Q13 may lead out of the phase a port. The circuit structures of the bridge arm b and the bridge arm c are the same as those of the bridge arm a, and are not repeated here.

Claims (14)

1. The photovoltaic optimizer is characterized by comprising a voltage conversion circuit, a first communication inductor, a second communication inductor, a communication transformer and a controller, wherein the input end of the voltage conversion circuit is used for being connected with a photovoltaic module, the first end of the first communication inductor and the first end of the second communication inductor are respectively connected with the positive electrode output end and the negative electrode output end of the voltage conversion circuit, the second end of the first communication inductor and the second end of the second communication inductor are respectively connected with the positive electrode input end and the negative electrode input end of the power converter through power lines, and the impedance of the first communication inductor is equal to that of the second communication inductor;
the second end of the first communication inductor and the second end of the second communication inductor are also respectively connected with a primary winding of the communication transformer, the first communication inductor and the second communication inductor receive a first high-frequency voltage component from the power converter through the power line, and the communication transformer is used for transforming the first high-frequency voltage component on the first communication inductor and the second communication inductor;
the controller is used for demodulating the transformed first high-frequency voltage component to acquire electric quantity information transmitted by the power converter.
2. The photovoltaic optimizer of claim 1, wherein the photovoltaic optimizer comprises a common mode inductor, wherein the magnetic core of the common mode inductor comprises two coils with opposite directions and same turns, one ends of the two coils are respectively connected with the positive output end and the negative output end of the voltage conversion circuit, and the other ends of the two coils are respectively connected with the first end of the first communication inductor and the first end of the second communication inductor.
3. The photovoltaic optimizer of claim 1, wherein the first communication inductor and the second communication inductor are coupled to a magnetic core, the first communication inductor and the second communication inductor are wound in opposite directions and have the same number of turns, the first end of the first communication inductor and the first end of the second communication inductor are the same name ends, and leakage inductance between the first communication inductor and the second communication inductor is greater than a set threshold.
4. The photovoltaic optimizer of claim 1, wherein the first communication inductor, the second communication inductor and the communication transformer are coupled on a magnetic core, the winding directions of the first communication inductor and the second communication inductor are opposite and the number of turns is the same, the first end of the first communication inductor and the first end of the second communication inductor are homonymous ends, and leakage inductance between the first communication inductor and the second communication inductor is greater than a set threshold;
The first communication inductance and the second communication inductance are used as primary windings of the communication transformer, secondary windings of the communication transformer are coupled to the magnetic core, and the transformation ratio of the communication transformer changes along with the change of leakage inductance between the first communication inductance and the second communication inductance.
5. The photovoltaic optimizer of claim 3 or 4, wherein the photovoltaic optimizer comprises a filter inductor connected between a positive output of the voltage conversion circuit and the first communication inductor.
6. The photovoltaic optimizer of any one of claims 1-5, wherein the controller is configured to generate a second high frequency voltage component based on modulation of electrical quantity information of the voltage conversion circuit;
the communication transformer may transform based on the second high-frequency voltage component and output to the power line to transmit electrical quantity information of the voltage conversion circuit to the power converter.
7. The photovoltaic optimizer of any one of claims 1-6, wherein the voltage conversion circuit comprises an input capacitor and an output capacitor, both ends of the input capacitor being used to connect the photovoltaic module and both ends of the output capacitor being used to couple with the first communication inductance and the second communication inductance;
The voltage conversion circuit further comprises a first switching tube and a second switching tube, the first switching tube and the second switching tube are connected in series and then connected in parallel to two ends of the input capacitor, the connecting ends of the first switching tube and the second switching tube are connected with one end of the output capacitor through an inductor, and the other end of the output capacitor is connected with the connecting ends of the second switching tube and the input capacitor.
8. The inverter is characterized by comprising an inverter circuit, a first communication inductor, a second communication inductor, a communication transformer and a controller, wherein the output end of the inverter circuit is used for being connected with an alternating current load, the first end of the first communication inductor and the first end of the second communication inductor are respectively connected with the positive input end and the negative input end of the inverter circuit, the second end of the first communication inductor and the second end of the second communication inductor are respectively connected with the positive output end and the negative output end of the photovoltaic optimizer through power lines, and the impedance of the first communication inductor and the impedance of the second communication inductor are equal;
the second end of the first communication inductor and the second end of the second communication inductor are also respectively connected with a primary winding of the communication transformer, the first communication inductor and the second communication inductor receive a first high-frequency voltage component from the photovoltaic optimizer through the power line, and the communication transformer is used for transforming the first high-frequency voltage component on the first communication inductor and the second communication inductor;
The controller is used for demodulating the transformed first high-frequency voltage component to acquire electric quantity information transmitted by the photovoltaic optimizer.
9. The inverter of claim 8, wherein the inverter comprises a common-mode inductor, the magnetic core of the common-mode inductor comprises two coils with opposite directions and same turns, one ends of the two coils are respectively connected with the positive input end and the negative input end of the inverter circuit, and the other ends of the two coils are respectively connected with the first end of the first communication inductor and the first end of the second communication inductor.
10. The inverter of claim 8, wherein the first communication inductor and the second communication inductor are coupled to a magnetic core, the winding directions of the first communication inductor and the second communication inductor are opposite and the number of turns is the same, the first end of the first communication inductor and the first end of the second communication inductor are the same-name ends, and leakage inductance between the first communication inductor and the second communication inductor is greater than a set threshold.
11. The inverter of claim 8, wherein the first communication inductor, the second communication inductor and the communication transformer are coupled on a magnetic core, winding directions of the first communication inductor and the second communication inductor are opposite and the winding directions are the same, a first end of the first communication inductor and a first end of the second communication inductor are homonymous ends, and leakage inductance between the first communication inductor and the second communication inductor is larger than a set threshold;
The first communication inductance and the second communication inductance are used as primary windings of the communication transformer, secondary windings of the communication transformer are coupled to the magnetic core, and the transformation ratio of the communication transformer changes along with the change of leakage inductance between the first communication inductance and the second communication inductance.
12. The inverter of claim 9 or 10, comprising a filter inductance connected between a positive input of the inverter circuit and the first communication inductance.
13. The inverter according to any one of claims 8-12, wherein the controller is configured to generate a second high-frequency voltage component based on modulation of electrical quantity information of the inverter circuit;
the communication transformer may transform based on the second high-frequency voltage component and output to the power line to transmit electrical quantity information of the inverter circuit to the photovoltaic optimizer.
14. The inverter of any one of claims 8-13, wherein the inverter circuit comprises at least one bridge arm and a first bus capacitor and a second bus capacitor connected in series, the bridge arm is connected in parallel to two ends of the first bus capacitor and the second bus capacitor connected in series, one end of the bridge arm is connected to a connection end of the first bus capacitor and the second bus capacitor, the other end of the bridge arm is used for connecting an ac load, and two ends of the first bus capacitor and the second bus capacitor connected in series are used for coupling with the first communication inductor and the second communication inductor.
CN202311523208.7A 2023-11-14 2023-11-14 Photovoltaic optimizer and inverter Pending CN117477933A (en)

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Application Number Priority Date Filing Date Title
CN202311523208.7A CN117477933A (en) 2023-11-14 2023-11-14 Photovoltaic optimizer and inverter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
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CN117477933A true CN117477933A (en) 2024-01-30

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