A dual-component series input micro-reverse control device and a control method thereof

Abstract

The application discloses a kind of double-component series input micro-reverse control device and its control method, it is related to multiple photovoltaic components, device includes inverter module, bus capacitor, first control unit and second control unit, maximum power point tracking MPPT module and shutoff, MPPT module includes at least one MPPT module, the double-component series input micro-reverse control device of the application obtains the measurement data of inverter module by first control unit, according to measurement data, control signal is sent to second control unit, again by second control unit, the state data and control signal of MPPT module are acquired, whether the shutoff is disconnected according to state data and control signal.Judgment guarantees that photovoltaic component can be promptly disconnected line when fault, and the voltage is lower after shutoff circuit double-component series input shutoff, improve the reliability of photovoltaic component shutoff protection circuit.

Description

Technical Field

[0001] This invention relates to the field of dual-component series input micro-inverter control technology, and in particular to a dual-component series input micro-inverter control device and its control method. Background Technology

[0002] In the prior art, there is a photovoltaic module shutdown protection circuit. This photovoltaic module shutdown protection circuit can ensure that the photovoltaic string is in a safe state when a single component or module fails, that is, when a single point of failure occurs.

[0003] However, in the aforementioned prior art, the output current of the photovoltaic module connected to the module shutdown device is detected by the current detection circuit to generate a current detection signal. Then, the reverse flow detection circuit determines that the photovoltaic module has entered the reverse flow state based on the current detection signal and generates a reverse flow signal. After the reverse flow control circuit receives the reverse flow signal, it controls the switch to conduct. In actual operation, the voltage after the dual-module series input of the shutdown circuit is turned off is relatively high, which reduces the reliability of the photovoltaic module shutdown protection circuit. Summary of the Invention

[0004] This invention provides a dual-component series-input micro-inverter control device and its control method, which solves the technical problem in the prior art where the switching transistor is turned on after receiving the backflow signal through the backflow control circuit. In actual operation, the voltage after the dual-component series-input turn-off of the shutdown circuit is relatively high, which reduces the reliability of the photovoltaic module shutdown protection circuit.

[0005] The present invention provides a dual-component series-connected micro-inverter control device, which involves multiple sets of photovoltaic modules, including an inverter module, a bus capacitor, a first control unit and a second control unit, a maximum power point tracking (MPPT) module and a shutdown device, wherein the MPPT module includes at least one set of MPPT modules;

[0006] Each MPPT module in each group has two input terminals connected to a photovoltaic module, and the photovoltaic modules are connected in series with the shutdown device.

[0007] Each adjacent MPPT module is interconnected via its output terminal;

[0008] The other output terminal of the MPPT module at the first end is connected to one end of the bus capacitor and the first input terminal of the inverter module, respectively.

[0009] The other output terminal of the MPPT module at the end is connected to the other end of the bus capacitor and the second input terminal of the inverter module, respectively.

[0010] The I / O interface of the first control unit is interconnected with the I / O interface of the second control unit;

[0011] The first control unit is used to acquire the measurement data of the inverter module and send a control signal to the second control unit according to the measurement data;

[0012] The second control unit is used to acquire the status data of the MPPT module and the control signal, and determine whether to disconnect the shutdown device based on the status data and the control signal.

[0013] Optionally, the first control unit includes a measurement data acquisition subunit and a data analysis subunit;

[0014] The measurement data acquisition subunit is used to acquire the measurement data and send the measurement data to the data analysis subunit;

[0015] The data analysis subunit is used to receive the measurement data and determine whether a line fault has occurred based on the comparison result between the measurement data and a preset fault range.

[0016] If a fault is detected in the line, the inverter module is disconnected.

[0017] If it is determined that the line is not faulty, then check whether the communication between the first control unit and the second control unit has timed out;

[0018] If the communication times out, the inverter module is disconnected;

[0019] If the communication does not time out, then determine whether the inverter module has been turned on;

[0020] If the inverter module is not turned on, determine whether the bus voltage in the measured data is greater than or equal to the start-up voltage;

[0021] If the bus voltage is greater than or equal to the starting voltage, then the inverter module is turned on;

[0022] If the inverter module is turned on, a low-level control signal is sent to the second control unit; if the inverter module is turned off, a high-level control signal is sent to the second control unit.

[0023] Optionally, the second control unit includes a status data acquisition subunit and a data processing subunit;

[0024] The status data acquisition subunit is used to acquire the status data and send the status data to the data processing subunit;

[0025] The data processing subunit is used to receive the status data and the control signal. If the control signal is a high-level control signal, the shut-off drive signal is sent to the shut-off device.

[0026] If the control signal is a low-level control signal, then determine whether the MPPT module has malfunctioned based on the status data;

[0027] If the MPPT module malfunctions, the shutdown drive signal will be sent to the shutdown device.

[0028] Optionally, the shutdown device includes a first capacitor, a first switching transistor, and a suppression diode;

[0029] One end of the first switching transistor is connected to the positive terminal of the first capacitor and the suppression diode, respectively;

[0030] The other end of the first switching transistor is connected to the other end of the first capacitor and the negative terminal of the suppression diode.

[0031] Optionally, the switch may further include a switch driver module;

[0032] The shutdown driver module is used to respond to the shutdown driver signal and control the first switch to operate.

[0033] Optionally, the MPPT module includes a second switching transistor, a third switching transistor, a second capacitor, a third capacitor, and a first inductor;

[0034] One end of the third capacitor forms the input terminal of the MPPT module and is connected to one end of the third switching transistor.

[0035] The other end of the third switch is connected to one end of the second switch and one end of the first inductor, respectively.

[0036] One end of the second capacitor forms the output terminal of the MPPT module and is connected to the other end of the first inductor;

[0037] The other end of the third capacitor constitutes another input terminal of the MPPT module, and is connected to the other end of the second switch and the other end of the second capacitor, respectively.

[0038] The other end of the second capacitor constitutes another output terminal of the MPPT module.

[0039] Optionally, the second control unit further includes a shutdown detection fault module;

[0040] The shutdown detection fault module is used to select the MPPT module input voltage difference in the status data and determine whether the input voltage difference is less than the voltage difference threshold.

[0041] If the input voltage difference is less than the voltage difference threshold, then the process jumps to the step of obtaining the status data of the MPPT module and the control signal, and determining whether to disconnect the shutdown device based on the status data and the control signal;

[0042] If the input voltage difference is greater than or equal to the voltage difference threshold, then the shutdown device is activated.

[0043] Optionally, the suppression diode is a 60V transient suppression diode.

[0044] Optionally, it also includes AC terminals and DC terminals;

[0045] The first output terminal and the second output terminal of the inverter module are connected to the power grid through the AC terminal.

[0046] The MPPT module is connected to the photovoltaic module via the DC terminal.

[0047] The second aspect of this invention provides a control method for a dual-component series-connected micro-inverter control device, the device comprising an inverter module, a shut-off circuit breaker, an MPPT module, a first control unit, and a second control unit, the method comprising:

[0048] In response to a fault detection request, the system acquires measurement data from the inverter module and status data from the MPPT module.

[0049] The first control unit acquires the measurement data of the inverter module and sends a control signal to the second control unit based on the measurement data.

[0050] The second control unit acquires the status data of the MPPT module and the control signal, and determines whether to disconnect the shutdown device based on the status data and the control signal.

[0051] As can be seen from the above technical solutions, the embodiments of the present invention have the following advantages:

[0052] This invention provides a dual-component series-input micro-inverter control device, comprising an inverter module, a bus capacitor, a first control unit, a second control unit, a maximum power point tracking (MPPT) module, and a shutdown device. The first and second control units acquire measurement data from the inverter module and status data from the MPPT module. Based on the status and measurement data, the device determines whether to disconnect the shutdown device. After the MPPT and shutdown device are disconnected, the voltage at the negative terminal of photovoltaic module PV1 and the positive terminal of photovoltaic module PV2 within the photovoltaic module is limited to a maximum of 60V. This solves the technical problem in existing technologies where the reverse-current control circuit controls the switching transistor's conduction by receiving reverse-current signals, resulting in a high voltage after the dual-component series-input shutdown circuit is disconnected, thus reducing the reliability of the photovoltaic module shutdown protection circuit. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of a dual-component serial input micro-inverter control device provided in an embodiment of the present invention;

[0055] Figure 2 The circuit diagram of the shut-off device provided in the embodiment of the present invention;

[0056] Figure 3 A circuit schematic diagram of the first MPPT module provided in an embodiment of the present invention;

[0057] Figure 4 The circuit schematic diagram of the second MPPT module provided in the embodiment of the present invention;

[0058] Figure 5 This is a schematic diagram of a hybrid input micro-inverter control device provided in an embodiment of the present invention;

[0059] Figure 6 This is a flowchart of a control method for a dual-component serial input micro-inverter control device, as provided in Embodiment 2 of the present invention.

[0060] The meanings of the reference numerals in the attached figures are as follows:

[0061] 1. First control unit; 2. Second control unit; 3. Inverter module; 4. Shut-off device; 5. Bus capacitor; 6. MPPT module; 7. Photovoltaic module; 8. Shut-off driver module. Detailed Implementation

[0062] This invention provides a dual-component series-input micro-inverter control device and its control method, which solves the technical problem that the voltage is high after the dual-component series-input turn-off of the existing turn-off circuit in actual operation, which reduces the reliability of the photovoltaic module turn-off protection circuit.

[0063] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0064] For easier understanding, please refer to Figure 1 The present invention provides a dual-component series input micro-inverter control device, which involves multiple photovoltaic modules 7, including an inverter module 3, a bus capacitor 5, a first control unit 1 and a second control unit 2, a maximum power point tracking (MPPT) module and a shutdown device 4. The MPPT module includes at least one set of MPPT modules 6.

[0065] Each MPPT module 6 has two input terminals connected to a photovoltaic module 7, and a circuit breaker 4 is connected in series between the photovoltaic modules 7.

[0066] Each adjacent MPPT module 6 is interconnected via its output terminal;

[0067] The other output terminal of the MPPT module 6 at the first end is connected to one end of the bus capacitor 5 and the first input terminal of the inverter module 3 respectively;

[0068] The other output terminal of the MPPT module 6 at the end is connected to the other end of the bus capacitor 5 and the second input terminal of the inverter module 3, respectively.

[0069] The I / O interface of the first control unit 1 is interconnected with the I / O interface of the second control unit 2;

[0070] The first control unit 1 is used to acquire the measurement data of the inverter module 3 and send control signals to the second control unit 2 based on the measurement data;

[0071] The second control unit 2 is used to acquire the status data and control signals of the MPPT module, and to determine whether to disconnect the circuit breaker 4 based on the status data and control signals.

[0072] In this embodiment of the invention, the dual-component series-connected micro-inverter control device includes an inverter module 3, a bus capacitor 5, a first control unit 1 and a second control unit 2, a maximum power point tracking (MPPT) module, and a shutdown device 4. The MPPT module includes at least one set of MPPT modules 6. The inverter module 3, the bus capacitor 5, the first control unit 1 and the second control unit 2, the MPPT module, and the shutdown device 4 can be interconnected via wires or cables. The first control unit 1 is used to acquire the measurement data of the inverter module 3 and send a control signal to the second control unit 2 based on the measurement data. The second control unit 2 then acquires the status data and control signal of the MPPT module and determines whether to disconnect the shutdown device 4 based on the status data and control signal.

[0073] It should be noted that the measurement data and status data acquired by the first control unit 1 and the second control unit 2 are obtained through AD analog signal acquisition. The measurement data includes the bus voltage Vbus, the AC side voltage of the inverter module 3 and the AC side current, and the status data includes the input voltage, input current, output voltage, output current and bus voltage of the MPPT module 6.

[0074] Each MPPT module 6 has two input terminals connected to a photovoltaic module 7. A circuit breaker 4 is connected in series between the photovoltaic modules 7. During normal operation, the second control unit 2 performs MPPT calculations based on the acquired status data, prioritizing the calculation of the power of each MPPT module 6. If the current power is less than the preset minimum power and the output voltage is less than the preset minimum voltage, the second control unit will gradually reduce the control voltage until the minimum MPPT voltage is reached. During the input voltage decrease, the maximum power and the corresponding input voltage reference value are recorded. After the input voltage drops to the minimum MPPT voltage, the input voltage reference value is assigned to the maximum power and the corresponding input voltage reference value. If the power difference between two adjacent MPPT modules 6 is less than the preset power value, the input voltage control reference value of the latter path is the average value of the input voltage of the former path, so as to reduce the power loss caused by MPPT tracking voltage fluctuations. If the power difference between two adjacent MPPT modules 6 is greater than the preset power value, the input voltage reference values ​​of both paths are the MPPT calculation output values, and the input voltage control value is the MPPT calculation output value, so that the input voltage is at the maximum power voltage, that is, the maximum power point. When a line fault is detected, the second control unit 2 will send a control signal to disconnect the series-connected shut-off device between the photovoltaic modules 7 and shut down the MPPT module 6.

[0075] Please see Figure 1-5As shown, the first control unit 1 includes a measurement data acquisition subunit and a data analysis subunit. The measurement data acquisition subunit is used to acquire measurement data and send the measurement data to the data analysis subunit. The data analysis subunit is used to receive the measurement data and, based on the comparison result of the measurement data with the preset fault range, determine whether a line fault has occurred. If a line fault is determined, the inverter module 3 is disconnected. If no line fault is determined, the communication between the first control unit 1 and the second control unit 2 is checked for timeout. If the communication timeout occurs, the inverter module 3 is disconnected. If the communication does not time out, it is determined whether the inverter module 3 is turned on. If the inverter module 3 is not turned on, it is determined whether the bus voltage in the measurement data is greater than or equal to the starting voltage. If the bus voltage is greater than or equal to the starting voltage, the inverter module 3 is turned on. If the inverter module 3 is turned on, a low-level control signal is sent to the second control unit 2. If the inverter module 3 is turned off, a high-level control signal is sent to the second control unit 2.

[0076] The high-level control signal refers to the high-level signal emitted by the first control unit 1 through the IO interface.

[0077] The low-level control signal refers to the low-level signal emitted by the first control unit 1 through the IO interface.

[0078] The measured data refers to the bus voltage V that the first control unit 1 parses from the AD analog signal. bus Inverter module 3 AC side voltage and AC side current.

[0079] Start-up voltage refers to the minimum voltage required for inverter module 3 to start.

[0080] Bus voltage refers to the voltage value at the first and second input terminals of inverter module 3.

[0081] The preset fault range refers to the rated range of the bus voltage, the rated range of the AC side voltage, and the rated range of the AC side current.

[0082] Communication timeout means that the communication or connection between the first control unit 1 and the second control unit 2 exceeds the preset data, indicating that there is a network problem between the first control unit and the second control unit.

[0083] In this embodiment of the invention, when fault detection is required, the measurement data acquisition subunit obtains measurement data from the inverter module 3 and sends the measurement data to the data analysis subunit. The data analysis subunit determines whether a line fault has occurred based on the comparison result between the measurement data and the preset fault range. If a line fault has occurred, the inverter module 3 will be disconnected. If no line fault has occurred, the communication between the first control unit 1 and the second control unit 2 will be checked for timeout. If the communication timeout occurs, the inverter module 3 will be disconnected. If the communication timeout does not occur, the inverter module 3 will be analyzed for operation. If the inverter module 3 is not operating, the bus voltage will be checked for greater than or equal to the starting voltage. If the bus voltage is greater than or equal to the starting voltage, the inverter module 3 will be turned on. If the inverter module 3 is turned on, a low level will be sent to the second control unit 2 through the IO interface. If the inverter module 3 is turned off, a high level will be sent to the second control unit 2 through the IO interface.

[0084] It should be noted that the comparison results between the measured data and the preset fault range are used to determine whether a line fault has occurred by comparing whether the measured data falls within the preset fault range. For example, the comparison involves whether the obtained bus voltage is within the rated range of the bus voltage. If the bus voltage is within the rated range, it indicates that the line is not faulty; if the bus voltage exceeds the rated range, it indicates that the line is faulty. Next, the comparison involves whether the obtained AC side voltage is within the rated range of the AC side. If the AC side voltage is within the rated range, it indicates that the line is not faulty; if the AC side voltage exceeds the rated range, it indicates that the line is faulty. Finally, the comparison involves whether the AC side current is within the rated range of the AC side. If the AC side current is within the rated range, it indicates that the line is not faulty; if the AC side current exceeds the rated range, it indicates that the line is faulty.

[0085] The second control unit 2 includes a status data acquisition subunit and a data processing subunit. The status data acquisition subunit is used to acquire status data and send the status data to the data processing subunit. The data processing subunit is used to receive status data and control signals. If the control signal is a high-level control signal, the shut-off drive signal is sent to the shut-off device 4. If the control signal is a low-level control signal, the system determines whether the MPPT module 6 has failed based on the status data. If the MPPT module 6 has failed, the shut-off drive signal is sent to the shut-off device 4.

[0086] The shut-off drive signal refers to the control current or control voltage issued by the data processing subunit. When the shut-off device 4 receives the control current or control voltage, it will disconnect the line connected to the shut-off device 4.

[0087] The status data refers to the input voltage, input current, output voltage, output current, and bus voltage of each MPPT module 6, which are parsed from the AD analog signal by the second control unit 2.

[0088] In this embodiment of the invention, when fault detection is required, the status data acquisition subunit acquires the status data of the MPPT module 6 and sends the status data to the data processing submodule. The data processing submodule determines what kind of control signal is based on the acquired status data and the control signal issued by the first control unit 1. If the control signal is a high-level control signal, the shutdown drive signal is sent to the shutdown unit 4. If the control signal is a low-level control signal, the status data is used to determine whether the MPPT module 6 has failed. If the MPPT module 6 has failed, the shutdown drive signal is sent to the shutdown unit 4.

[0089] It should be noted that determining whether MPPT module 6 has malfunctioned based on status data is done by comparing whether the status data falls within a preset fault range for MPPT module 6. For example, it checks whether the input voltage of MPPT module 6 is within its rated input voltage range. If the input voltage is within the rated input voltage range, then MPPT module 6 is not malfunctioning; if the input voltage exceeds the rated input voltage range, then MPPT module 6 has malfunctioned. Similarly, it checks whether the input current of MPPT module 6 is within its rated input current range. If the input current is within the rated input current range, then MPPT module 6 is not malfunctioning; if the input current exceeds the rated input current range, then MPPT module 6 has malfunctioned. Finally, it checks whether the output voltage of MPPT module 6 is within its rated output voltage range. If the output voltage is within the rated output voltage range, then MPPT module 6 is not malfunctioning; if the output voltage exceeds the rated output voltage range, then MPPT module 6 has malfunctioned. Determine if the output current of MPPT module 6 is within its rated output current range. If the output current is within the rated output current range, it indicates that MPPT module 6 is not faulty. If the output current exceeds the rated output current range, it indicates that MPPT module 6 is faulty. Determine if the bus voltage is within its rated bus voltage range. If the bus voltage is within the rated bus voltage range, it indicates that MPPT module 6 is not faulty. If the bus voltage exceeds the rated bus voltage range, it indicates that MPPT module 6 is faulty.

[0090] The preset fault range of MPPT module 6 refers to the range of rated input voltage, rated input current, rated output voltage, rated output current, and rated bus voltage of MPPT module 6.

[0091] Please see Figure 2 The circuit breaker 4 includes a first capacitor C1, a first switching transistor Q1, and a suppressor diode TVS1. One end of the first switching transistor Q1 is connected to the positive terminals of the first capacitor C1 and the suppressor diode TVS1, respectively. The other end of the first switching transistor Q1 is connected to the other end of the first capacitor C1 and the negative terminal of the suppressor diode TVS1, respectively. The circuit breaker 4 also includes a circuit breaker drive module 8, which is used to respond to the circuit breaker drive signal and control the first switching transistor Q1 to operate.

[0092] In this embodiment of the invention, the shutdown device 4 includes a first capacitor C1, a first switching transistor Q1, a suppression diode TVS1, and a shutdown device driving module 8. One end of the first switching transistor Q1 is connected to the positive terminals of the first capacitor C1 and the suppression diode TVS1, respectively. The other end of the first switching transistor Q1 is connected to the other end of the first capacitor C1 and the negative terminal of the suppression diode TVS1, respectively. When the second control unit 2 sends the shutdown device driving module 8, the shutdown device driving module responds to the request of the shutdown device driving signal and sends a control voltage or control current to the first switching transistor Q1, causing the first switching transistor Q1 to turn off.

[0093] It should be noted that the suppression diode TVS1 is a 60V transient suppression diode. When the first switching transistor Q1 receives control current or control voltage and disconnects the circuit, the suppression diode TVS1 can limit the voltage between the negative terminal of photovoltaic module PV1 and the positive terminal of photovoltaic module PV2 to a maximum of 60V, so as to ensure that the voltage between any two lines between photovoltaic modules is less than 80V.

[0094] Please see Figure 4 The MPPT module 6 includes a second switch Q2, a third switch Q3, a second capacitor C2, a third capacitor C3, and a first inductor L1. One end of the third capacitor C3 forms the input terminal of the MPPT module 6 and is connected to one end of the third switch Q3. The other end of the third switch Q3 is connected to one end of the second switch Q2 and one end of the first inductor L1. One end of the second capacitor C2 forms the output terminal of the MPPT module 6 and is connected to the other end of the first inductor L1. The other end of the third capacitor C3 forms another input terminal of the MPPT module 6 and is connected to the other end of the second switch Q2 and the other end of the second capacitor C2. The other end of the second capacitor C2 forms another output terminal of the MPPT module 6.

[0095] In this embodiment of the invention, the MPPT module 6 includes a second switch Q2, a third switch Q3, a second capacitor C2, a third capacitor C3, and a first inductor L1. One end of the third capacitor C3 is connected to the photovoltaic module 7 and is also connected to one end of the third switch Q3. The other end of the third switch Q3 is connected to one end of the second switch Q2 and one end of the first inductor L1. One end of the second capacitor C2 forms the output terminal of the MPPT module 6 and is connected to the other end of the first inductor L1. The other end of the third capacitor C3 forms the other input terminal of the MPPT module 6 and is connected to the other end of the second switch Q2 and the other end of the second capacitor C2. The other end of the second capacitor C2 is connected to the photovoltaic module 7. The MPPT module 6 is adjusted according to the MPPT algorithm of the second control unit 2 so that the input voltage of the MPPT module 6 is equal to the maximum power point voltage.

[0096] It should be noted that MPPT module 6 also includes a second connection method; please refer to [link / reference]. Figure 3 The MPPT module 6 includes a second capacitor C2, a third capacitor C3, a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, and a first inductor L1. One end of the third capacitor C3 forms the first input terminal of the MPPT module 6, and one end of the third capacitor C3 is connected to one end of the fifth switch Q5. The other end of the fifth switch Q5 is connected to one end of the second switch Q2 and one end of the first inductor L1. The other end of the first inductor L1 is connected to one end of the third switch Q3 and one end of the fourth switch Q4. The other end of the fourth switch Q4 is connected to one end of the second capacitor C2. One end of the second capacitor C2 forms the first output terminal of the MPPT module 6. The other end of the third capacitor C3 forms the second input terminal of the MPPT module 6, and the other end of the third capacitor C3 is connected to the other ends of the second switch Q2, the third switch Q3, and the second capacitor C2. The other end of the second capacitor C2 forms the second output terminal of the MPPT module 6.

[0097] The second control unit 2 also includes a shutdown detection fault module. The shutdown detection fault module is used to select the input voltage difference of MPPT module 6 in the status data and determine whether the input voltage difference is less than the voltage difference threshold. If the input voltage difference is less than the voltage difference threshold, the module jumps to the step of obtaining the status data and control signal of MPPT module and determining whether to disconnect the switch 4 based on the status data and control signal. If the input voltage difference is greater than or equal to the voltage difference threshold, the switch 4 is turned on.

[0098] The differential voltage threshold refers to the rated voltage difference of MPPT module 6.

[0099] In this embodiment of the invention, the second control unit further includes a shutdown detection fault module, which is used to select the input voltage difference of MPPT module 6 in the status data, and determine whether the input voltage difference is less than the voltage difference threshold. If the input voltage difference is less than the voltage difference threshold, it indicates that the shutdown device 4 may be faulty. Based on the comparison results of the input voltage, input current, output voltage, output current and bus voltage of the MPPT module with the preset threshold, it is determined whether the disconnector 4 needs to be disconnected by the control signal. If the input voltage difference is greater than or equal to the voltage difference threshold, the shutdown device 4 is turned on.

[0100] Figure 5 The present invention provides a hybrid input circuit, wherein the photovoltaic array to be used also includes a single photovoltaic module.

[0101] The first output terminal of a single photovoltaic module constitutes the first output terminal of the photovoltaic array to be connected.

[0102] The second output terminal of a single photovoltaic module constitutes the second output terminal of the photovoltaic array to be connected.

[0103] In this embodiment of the invention, the dual-component series input micro-inverter control device can also be connected to a hybrid input circuit, where the first output terminal of a single photovoltaic module constitutes the first output terminal of the photovoltaic group to be connected, and the second output terminal of a single photovoltaic module constitutes the second output terminal of the photovoltaic group to be connected.

[0104] The present invention provides a dual-component series-input micro-inverter control device, comprising an inverter module, a bus capacitor, a first control unit, a second control unit, a maximum power point tracking (MPPT) module, and a shutdown device. The first control unit acquires measurement data from the inverter module and sends a control signal to the second control unit based on this data. The second control unit then acquires the status data of the MPPT module and the control signal from the first control unit. Based on the status data and the control signal, it determines whether to disconnect the shutdown device. After the MPPT and shutdown device are disconnected, the voltage at the negative terminal of photovoltaic module PV1 and the positive terminal of photovoltaic module PV2 is limited to a maximum of 60V, ensuring that the voltage between any two lines between the modules is less than 80V. This solves the technical problem in the prior art where the backflow control circuit controls the switching transistor's conduction by receiving backflow signals, resulting in a high voltage after the dual-component series input of the shutdown circuit is disconnected, thus reducing the reliability of the photovoltaic module shutdown protection circuit.

[0105] Please see Figure 6 , Figure 6 The flowchart illustrates the steps of a control method for a dual-component serial input micro-inverter control device provided in Embodiment 2 of the present invention.

[0106] The present invention provides a control method for a dual-component series-input micro-inverter control device, applicable to any of the aforementioned dual-component series-input micro-inverter control devices. The device includes an inverter module, a shut-off device, an MPPT module, a first control unit, and a second control unit. The method includes:

[0107] Step 601: Respond to the fault detection request and obtain the measurement data of the inverter module and the status data of the MPPT module.

[0108] A fault detection request refers to a fault detection signal sent by technicians to detect whether the inverter module and MPPT module have malfunctioned.

[0109] The measurement data refers to the bus voltage Vbus, inverter module AC side voltage, and inverter module AC side current obtained by the first control unit through AD analog signals.

[0110] Status data refers to the input voltage, input current, output voltage, output current, and bus voltage of the MPPT module, which are obtained by the second control unit through AD analog signals.

[0111] In this embodiment of the invention, when the dual-component series-input micro-inverter control device receives a fault detection signal from a technician, the first control unit in the dual-component series-input micro-inverter control device will obtain the bus voltage, AC side voltage, and AC side current of the inverter module through the AD analog signal of the inverter module. The second control unit in the dual-component series-input micro-inverter control device will obtain the input voltage, input current, output voltage, output current, and bus voltage of the MPPT module through the AD analog signal of the MPPT module.

[0112] Step 602: Obtain the measurement data of the inverter module through the first control unit, and send the control signal to the second control unit according to the measurement data.

[0113] Optionally, step 602 further includes the following sub-steps:

[0114] Based on the comparison results between the measured data and the preset fault range, it is determined whether a line fault has occurred.

[0115] If a line fault is detected, the inverter module will be disconnected.

[0116] If it is determined that there is no fault in the line, then check whether the communication between the first control unit and the second control unit has timed out.

[0117] If communication times out, disconnect the inverter module.

[0118] If the communication does not time out, then determine whether the inverter module has been turned on.

[0119] If the inverter module is not turned on, determine whether the bus voltage in the measured data is greater than or equal to the starting voltage.

[0120] If the bus voltage is greater than or equal to the starting voltage, the inverter module will be turned on.

[0121] If the inverter module is enabled, a low-level control signal is sent to the second control unit.

[0122] If the inverter module is off, a high-level control signal is sent to the second control unit.

[0123] Communication timeout refers to the communication between the first control unit and the second control unit exceeding a preset time, indicating a network malfunction between the two control units.

[0124] The preset fault range refers to the rated range of the inverter module bus voltage, the rated range of the AC side voltage, and the rated range of the AC side current.

[0125] Control signals refer to the level control signals issued by the first control unit. For example, high-level control signals and low-level control signals.

[0126] In this embodiment of the invention, when measurement data is acquired, the system compares the measurement data with a preset fault range to determine whether a line fault has occurred. If a line fault has occurred, the inverter module is disconnected. If no line fault has occurred, the system checks if the communication between the first control unit and the second control unit has exceeded a preset time. If the communication between the first control unit and the second control unit times out, the inverter module is disconnected. If the communication does not time out, the system determines whether the inverter module is turned on. If the inverter module is not turned on, the system determines whether the bus voltage is greater than or equal to the starting voltage. If the bus voltage is greater than or equal to the starting voltage, the inverter module is turned on. If the inverter module is turned on, a low-level control signal is sent to the second control unit. If the inverter module is turned off, a high-level control signal is sent to the second control unit.

[0127] It should be noted that the comparison between the measured data and the preset fault range determines whether a line fault has occurred by judging whether the measured data falls within the preset fault range. For example, it checks whether the bus voltage is within its rated range. If the bus voltage is within its rated range, the line is not faulty; if the bus voltage exceeds its rated range, the line is faulty. Next, it checks whether the acquired AC side voltage is within its rated range. If the AC side voltage is within its rated range, the line is not faulty; if the AC side voltage exceeds its rated range, the line is faulty. Finally, it checks whether the AC side current is within its rated range. If the AC side current is within its rated range, the line is not faulty; if the AC side current exceeds its rated range, the line is faulty.

[0128] Step 603: Obtain the status data and control signals of the MPPT module through the second control unit, and determine whether to disconnect the circuit breaker based on the status data and control signals.

[0129] Optionally, step 603 further includes the following sub-steps:

[0130] If the control signal is a high-level control signal, then the shutdown drive signal will be sent to the shutdown device.

[0131] If the control signal is a low-level control signal, then the status data is used to determine whether the MPPT module has malfunctioned.

[0132] If the MPPT module malfunctions, a shutdown drive signal will be sent to the shutdown device.

[0133] The shut-off drive signal refers to the control current or control voltage issued by the second control unit. When the shut-off receives the control current or control voltage, it will disconnect the circuit connected to the shut-off.

[0134] In this embodiment of the invention, when the input voltage, input current, output voltage, output current, bus voltage, and control signal issued by the first control unit of each MPPT module are obtained, if the control signal is a high-level control signal, a shutdown drive signal is sent to the shutdown unit to disconnect the line connected to the shutdown unit; if the control signal is a low-level control signal, it is determined whether the MPPT module has malfunctioned based on the input voltage, input current, output voltage, output current, and bus voltage. If the MPPT module has malfunctioned, a shutdown drive signal is sent to the shutdown unit to disconnect the line connected to the shutdown unit.

[0135] It should be noted that determining whether an MPPT module is faulty based on its input voltage, input current, output voltage, output current, and bus voltage is done by comparing whether these parameters fall within a preset MPPT module fault range. For example, checking if the MPPT module's input voltage is within its rated input voltage range indicates that the module is not faulty; conversely, checking if the input voltage exceeds the rated range indicates a fault.

[0136] In this embodiment of the invention, when the dual-component series-connected micro-inverter control device receives a fault detection signal from a technician, it acquires the measurement data of the inverter module and the status data of the MPPT module. By comparing the measurement data with the preset fault range, it determines whether a line fault has occurred. If a line fault has occurred, the inverter module is shut down. If no line fault has occurred, it detects that the communication between the first control unit and the second control unit has exceeded a preset time. If the communication between the first control unit and the second control unit times out, the inverter module is disconnected. If the communication does not time out, it determines whether the inverter module is turned on. If the inverter module is not turned on, it determines whether the bus voltage is... If the bus voltage is greater than or equal to the starting voltage, the inverter module is turned on. If the inverter module is not turned on, a low-level control signal is sent to the second control unit. If the inverter module is not turned on, a high-level control signal is sent to the second control unit. If the control signal received by the second control unit is a high-level control signal, a shutdown drive signal is sent to the shutdown unit to disconnect the line connected to the shutdown unit. If the control signal received by the second control unit is a low-level control signal, the status data of the MPPT module is used to determine whether the MPPT module has failed. If the MPPT module has failed, a shutdown drive signal is sent to the shutdown unit to disconnect the line connected to the shutdown unit. This avoids the situation where the voltage is high after the dual-component series input of the shutdown circuit is disconnected during actual operation, limits the voltage value after the dual-component series input of the shutdown circuit is turned off, and improves the reliability of the photovoltaic module shutdown protection circuit.

[0137] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0138] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0139] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-component series-connected micro-inverter control device, characterized in that, It involves multiple sets of photovoltaic modules, including inverter modules, bus capacitors, first control units and second control units, maximum power point tracking (MPPT) modules and shutdown devices, wherein the MPPT modules include at least one set of MPPT modules; Each MPPT module in each group has two input terminals connected to a photovoltaic module, and the photovoltaic modules are connected in series with the shutdown device. Each adjacent MPPT module is interconnected via its output terminal; The other output terminal of the MPPT module at the first end is connected to one end of the bus capacitor and the first input terminal of the inverter module, respectively. The other output terminal of the MPPT module at the end is connected to the other end of the bus capacitor and the second input terminal of the inverter module, respectively. The I / O interface of the first control unit is interconnected with the I / O interface of the second control unit; The first control unit is used to acquire the measurement data of the inverter module and send a control signal to the second control unit according to the measurement data; The second control unit is used to acquire the status data of the MPPT module and the control signal, and determine whether to disconnect the shutdown device based on the status data and the control signal; The second control unit includes a status data acquisition subunit and a data processing subunit; The status data acquisition subunit is used to acquire the status data and send the status data to the data processing subunit; The data processing subunit is used to receive the status data and the control signal. If the control signal is a high-level control signal, the shutdown drive signal is sent to the shutdown device. If the control signal is a low-level control signal, then determine whether the MPPT module has malfunctioned based on the status data; If the MPPT module malfunctions, the shutdown drive signal will be sent to the shutdown device. The shutdown device includes a first capacitor, a first switching transistor, and a suppression diode; One end of the first switching transistor is connected to the positive terminal of the first capacitor and the suppression diode, respectively; The other end of the first switching transistor is connected to the other end of the first capacitor and the negative terminal of the suppression diode, respectively; The first control unit includes a measurement data acquisition subunit and a data analysis subunit; The measurement data acquisition subunit is used to acquire the measurement data and send the measurement data to the data analysis subunit; The data analysis subunit is used to receive the measurement data and determine whether a line fault has occurred based on the comparison result between the measurement data and a preset fault range. If a fault is detected in the line, the inverter module is disconnected. If it is determined that the line is not faulty, then check whether the communication between the first control unit and the second control unit has timed out; If the communication times out, the inverter module is disconnected; If the communication does not time out, then determine whether the inverter module has been turned on; If the inverter module is not turned on, determine whether the bus voltage in the measured data is greater than or equal to the start-up voltage; If the bus voltage is greater than or equal to the starting voltage, then the inverter module is turned on; If the inverter module is turned on, a low-level control signal is sent to the second control unit; If the inverter module is off, a high-level control signal is sent to the second control unit.

2. The dual-component series input micro-inverter control device according to claim 1, characterized in that, The shut-off device also includes a shut-off device driver module; The shutdown driver module is used to respond to the shutdown driver signal and control the first switch to operate.

3. The dual-component series input micro-inverter control device according to claim 1, characterized in that, The MPPT module includes a second switching transistor, a third switching transistor, a second capacitor, a third capacitor, and a first inductor; One end of the third capacitor forms the input terminal of the MPPT module and is connected to one end of the third switching transistor. The other end of the third switch is connected to one end of the second switch and one end of the first inductor, respectively. One end of the second capacitor forms the output terminal of the MPPT module and is connected to the other end of the first inductor; The other end of the third capacitor constitutes another input terminal of the MPPT module, and is connected to the other end of the second switch and the other end of the second capacitor, respectively. The other end of the second capacitor constitutes another output terminal of the MPPT module.

4. The dual-component series-connected micro-inverter control device according to claim 1, characterized in that, The second control unit also includes a shutdown detection fault module; The shutdown detection fault module is used to select the MPPT module input voltage difference in the status data and determine whether the input voltage difference is less than the voltage difference threshold. If the input voltage difference is less than the voltage difference threshold, then the process jumps to the step of obtaining the status data of the MPPT module and the control signal, and determining whether to disconnect the shutdown device based on the status data and the control signal; If the input voltage difference is greater than or equal to the voltage difference threshold, then the shutdown device is activated.

5. The dual-component series input micro-inverter control device according to claim 1, characterized in that, The suppression diode is a 60V transient suppression diode.

6. The dual-component series-connected micro-inverter control device according to claim 1, characterized in that, It also includes AC terminals and DC terminals; The first output terminal and the second output terminal of the inverter module are connected to the power grid through the AC terminal. The MPPT module is connected to the photovoltaic module via the DC terminal.

7. A control method for a dual-component series-connected micro-inverter control device, characterized in that, A dual-component series-input micro-inverter control device according to any one of claims 1-6, the device comprising an inverter module, a shut-off circuit breaker, an MPPT module, a first control unit, and a second control unit, the method comprising: In response to a fault detection request, the system acquires measurement data from the inverter module and status data from the MPPT module. The first control unit acquires the measurement data of the inverter module and sends a control signal to the second control unit based on the measurement data. The second control unit acquires the status data of the MPPT module and the control signal, and determines whether to disconnect the shutdown device based on the status data and the control signal.

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