Micro inverter supporting photovoltaic cloud platform system

Abstract

The utility model relates to the technical field of inverters, in particular to a micro inverter supporting a photovoltaic cloud platform system, which comprises a digital signal processor (DSP) core processor which is respectively connected with a primary side flyback boosting unit, a power frequency inversion output unit, a communication unit and a sampling protection unit. The auxiliary power supply is respectively connected with the DSP core processor, the primary side flyback boost unit and the power frequency inversion output unit; and the communication unit is connected and communicated with the photovoltaic cloud platform through wireless signal transmission. According to the utility model, the design faces intelligent control and miniaturization, and household photovoltaic double-path direct current can be converted into alternating current; the system is small in structure, is used in a modularized manner, can achieve the assembly-level monitoring through cooperation with a cloud platform, can respond to the dispatching of a power grid more quickly and finely, and can better guarantee the power generation amount. And a multi-protection design is adopted, and the whole system is designed by referring to related electrical safety standards and regulations, so that electrical risks are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of inverters, in particular to a micro-inverter supporting a photovoltaic cloud platform system. Background Art

[0002] Under the dual carbon strategy, the installed capacity of renewable energy sources such as wind power and photovoltaics has grown rapidly. As the "heart" of photovoltaic power generation, the development of inverters has been particularly noteworthy. Microinverters, particularly due to their superior efficiency and safety, have attracted industry attention and hold enormous potential for future development. Microinverters are being applied down to the component level, enabling individual maximum power point tracking and inversion for each photovoltaic module. As photovoltaics become the primary power source in the future, this advantage of microinverters will become increasingly evident. Combined with cloud platform technology, they can respond to grid dispatch requests faster and more precisely, with accurate information down to the individual module, ensuring better power generation.

[0003] The existing inverters that support photovoltaic cloud platform systems have complex structures, occupy a large space, and the system's safety protection design needs to be enhanced. There are high electrical risks when abnormalities occur. Utility Model Content

[0004] Some simplifications or omissions may be made in this section and the abstract of the specification and the title of the utility model of this application to avoid blurring the purpose of this section, the abstract of the specification and the title of the utility model, and such simplifications or omissions shall not be used to limit the scope of the utility model.

[0005] In view of the fact that the existing inverter supporting the photovoltaic cloud platform system in the above-mentioned prior art has a complex structure, occupies a large space, and has a safety protection design that needs to be improved, and there is still a high electrical risk when an abnormality occurs, the present utility model is proposed.

[0006] Therefore, the purpose of this utility model is to provide a micro-inverter that supports a photovoltaic cloud platform system.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a micro-inverter supporting a photovoltaic cloud platform system, comprising:

[0008] The DSP core processor is respectively connected to the primary side flyback boost unit, the power frequency inverter output unit, the communication unit and the sampling protection unit;

[0009] Auxiliary power supply, which is respectively connected to the DSP core processor, the primary side flyback boost unit and the power frequency inverter output unit;

[0010] The communication unit is connected and communicated with the photovoltaic cloud platform via wireless signal transmission.

[0011] As a preferred solution of the micro-inverter supporting the photovoltaic cloud platform system described in the present invention, the DSP core processor includes an SPWM control module for controlling the primary side drive and a PWM control module for controlling the industrial frequency side.

[0012] As a preferred solution of the micro-inverter supporting the photovoltaic cloud platform system described in the present invention, the primary side flyback boost unit is connected to the SPWM control module and includes no less than two sets of parallel flyback drive circuits.

[0013] As a preferred solution of the micro-inverter supporting the photovoltaic cloud platform system described in the utility model, wherein: the industrial frequency inverter output unit is connected to the PWM control module, including a full-bridge inverter circuit connected to the power grid.

[0014] As a preferred solution of the micro-inverter supporting the photovoltaic cloud platform system described in the present invention, the flyback drive circuit is provided with a transformer and a switch tube for converting the voltage into a pulse signal.

[0015] As a preferred solution of the micro-inverter supporting the photovoltaic cloud platform system described in the utility model, wherein: the full-bridge inverter circuit is provided with a thyristor and a power MOS tube, and the thyristor and the power MOS tube form an inverter bridge structure.

[0016] As a preferred solution of the micro-inverter supporting the photovoltaic cloud platform system described in the utility model, wherein: the sampling protection unit includes a signal processing circuit connected to the primary side and the power frequency side respectively, and an AD sampling signal circuit and a hardware comparator circuit respectively connected to the DSP core processor;

[0017] Among them, the sampling sources of the signal processing circuit include a primary side sampling module and a power grid sampling module on the power frequency side.

[0018] As a preferred solution of the micro-inverter supporting the photovoltaic cloud platform system described in the present invention, the primary side sampling module includes primary side voltage sampling, primary side current sampling and primary side MOS voltage sampling.

[0019] As an optimal solution for the micro-inverter supporting the photovoltaic cloud platform system described in the utility model, the grid sampling module includes DC bus voltage sampling, grid voltage sampling, grid zero-crossing sampling and grid current sampling.

[0020] As a preferred solution of the micro-inverter supporting the photovoltaic cloud platform system described in the utility model, the auxiliary power supply outputs three power supplies, wherein the photovoltaic side power supply input to the primary side flyback boost unit and the grid side power supply input to the industrial frequency inverter output unit are isolated from each other.

[0021] The beneficial effects of the micro-inverter supporting the photovoltaic cloud platform system of the utility model are as follows: the design of the utility model is oriented towards intelligent control and miniaturization, and can realize the conversion of dual-circuit direct current of household photovoltaics into alternating current; the structure is compact and modular, and it can realize component-level monitoring in conjunction with the cloud platform, which can respond to the dispatch of the power grid faster and more precisely, and can better guarantee the power generation; it adopts a multiple protection design, and the overall system is designed with reference to relevant electrical safety standards and regulations to reduce electrical risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 Schematic diagram of the system architecture of the present invention.

[0024] Figure 2 This is a schematic diagram of the topological structure of the DSP core processor of the present utility model.

[0025] Figure 3 This is a schematic diagram of the topological structure of the sampling protection unit of the present invention.

[0026] Figure 4 This is the flyback boost principle diagram of the utility model.

[0027] Figure 5 For this utility model Figure 4 Schematic diagram of the equivalent chopper.

[0028] Figure 6 This is the full-bridge inverter principle diagram of the utility model.

[0029] Figure 7 For this utility model Figure 6 Schematic diagram of the equivalent chopper.

[0030] In the figure: 100, DSP core processor; 101, SPWM control module; 102, PWM control module; 200, primary side flyback boost unit; 201, flyback drive circuit; 201a, transformer; 201b, switch tube; 300, industrial frequency inverter output unit; 301, full-bridge inverter circuit; 301a, thyristor; 301b, power MOS tube; 400, communication unit; 500, sampling and protection unit; 501, signal processing circuit; 501a, primary side sampling module; 501b, power grid sampling module; 600, auxiliary power supply. DETAILED DESCRIPTION

[0031] In order to make the objectives, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below with reference to the accompanying drawings.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0034] Example 1

[0035] Reference Figure 1-Figure 3 , which is the first embodiment of the utility model, provides a micro-inverter supporting a photovoltaic cloud platform system, which has a simpler structure and occupies a relatively small space, and includes: a DSP core processor 100 and an auxiliary power supply 600. Specifically, the DSP core processor 100 is respectively connected to a primary-side flyback boost unit 200, an industrial frequency inverter output unit 300, a communication unit 400, and a sampling protection unit 500.

[0036] DSP stands for Digital Signal Processing, a technology that allows digital signal processing. DSP core processor 100 is primarily a DSP chip, specifically a chip capable of implementing digital signal processing. DSP core processor 100 employs a Harvard architecture with separate program and data memory, features a dedicated hardware multiplier, utilizes extensive pipeline operations, and provides specialized DSP instructions for rapidly implementing various digital signal processing algorithms.

[0037] Furthermore, the auxiliary power supply 600 is respectively connected to the DSP core processor 100, the primary side flyback boost unit 200 and the industrial frequency inverter output unit 300, and the communication unit 400 is connected and communicated with the photovoltaic cloud platform through wireless signal transmission.

[0038] The DSP core processor 100 includes an SPWM control module 101 for controlling the primary-side drive, and a PWM control module 102 for controlling the power-frequency side. PWM, short for Pulse Width Modulation, varies the duty cycle of the output square wave to change the equivalent output voltage. It is widely used in motor speed regulation and valve control, such as in electric vehicle motor speed regulation.

[0039] SPWM, the full name of which is Sinusoidal PWM, changes the modulation pulse mode based on PWM. The pulse width and time duty cycle are arranged according to the sine law. In this way, the output waveform can be made into a sine wave output after proper filtering. It is widely used in DC-AC inverters, etc.

[0040] The micro-inverter device of this embodiment is a power conversion device, which is generally used in solar photovoltaic systems to convert the DC power generated by photovoltaic PV solar panels into AC power to supply household or commercial electrical equipment. The power logic is to output the power from the primary side flyback boost unit 200 to the industrial frequency inverter output unit 300 to the power grid or electrical equipment, that is, it involves the primary side SPWM control module 101 and the industrial frequency side PWM control module 102. The DSP core processor 100 serves as the control core of the entire device and implements software control of the entire function. The sampling and protection unit 500 includes signal processing, AD (analog-to-digital conversion) sampling, and hardware parameter protection. The sampled data is transmitted to the DSP core processor 100.

[0041] The communication unit 400 of this embodiment is WIFI / Bluetooth wireless communication, which involves communication with the upper cloud platform to realize data interaction between the DSP core processor 100 and the upper photovoltaic cloud platform system service; the auxiliary power supply 600 supplies power to each part of the power supply circuit and adopts an isolation transformer design to meet the safety requirements of the system's photovoltaic side and grid side isolation design.

[0042] Example 2

[0043] Reference Figure 2-Figure 7 , which is the second embodiment of the present utility model. Different from the previous embodiment, this embodiment provides a flyback drive circuit 201 and a full-bridge inverter circuit 301 to realize the conversion of household photovoltaic dual-path DC power into AC power.

[0044] Specifically, the primary-side flyback boost unit 200 is connected to the SPWM control module 101 and includes at least two parallel flyback drive circuits 201. The SPWM control module 101 implements primary-side SPWM control, and the flyback drive circuit 201 implements flyback drive. In addition, the primary-side flyback boost unit 200 also includes a flyback transformer switching power supply, that is, when the primary coil of the transformer is excited by the DC pulse voltage, the secondary coil of the transformer does not provide power output to the load, and only provides power output to the load after the excitation voltage of the primary coil of the transformer is turned off.

[0045] According to the design requirements of the device power output, four flyback power supplies are connected in parallel in this embodiment to boost the DC power on the photovoltaic side to the DC bus output through the DC-DC. The DC-DC boost circuit is a power supply circuit that mainly increases the voltage of the power supply. It is worth noting that the number of flyback power supplies set is affected by their own power and temperature thresholds, and can be adaptively adjusted as needed during actual use.

[0046] Specifically, the power frequency inverter output unit 300 is connected to the PWM control module 102 and includes a full-bridge inverter circuit 301 connected to the power grid 301a via a grid-connected EMI circuit 301b. The primary purpose of the EMI circuit is to eliminate and suppress electromagnetic interference (EMI). It is commonly used in grid-connected circuits to ensure the stable operation of power or electronic systems while preventing harmful external EMI. In this embodiment, the power frequency inverter output unit 300 implements PWM control via the PWM control module 102 and full-bridge inverter drive via the full-bridge inverter circuit 301, thereby converting DC power into 50 / 60Hz AC power. The power frequency inverter must meet grid-connected regulatory requirements.

[0047] Furthermore, the flyback drive circuit 201 is equipped with a transformer 201a and a switch 201b that converts voltage into a pulse signal. The primary side of the micro-inverter device in this embodiment utilizes the flyback boost principle. The flyback power supply operates by switching the input voltage at high frequency through a switch, converting the voltage into a pulse signal, which is then isolated and transformed by a transformer, ultimately outputting the desired voltage. In this embodiment, the high-frequency switch 201b is a DSP-controlled SPWM drive on the primary side. An algorithm compares the sinusoidal modulated wave with the carrier wave, and a phase-locked loop calculates the leading and trailing edges of the pulse generated at the intersection of the curves, generating an SPWM wave equivalent to a sine wave with a sinusoidal pulse width and equal amplitude.

[0048] When the switch tube 201b is turned on, the input voltage is transformed by the transformer 201a, and the output voltage rises and is filtered by the output capacitor; when the switch tube 201b is turned off, the induced electromotive force on the secondary side of the transformer 201a will cause the diode to turn on, at which time the capacitor begins to discharge and the output voltage begins to drop, and the switch tube begins to turn on again. The cycle repeats, and the electric energy is flyback-boosted and then collected into the DC bus. The power regulation can be controlled by the DSP control algorithm; by modulating the SPWM wave, the DC bus is a continuous equivalent sine half wave.

[0049] The full-bridge inverter circuit 301 is equipped with thyristors 301a and power MOS transistors 301b, forming an inverter bridge structure. The inverter side of the micro-inverter device in this embodiment utilizes the single-phase full-bridge inverter principle. A single-phase inverter circuit converts AC power into DC power. Thyristors 301a and power MOS transistors 301b form an inverter bridge to convert DC power into AC power. The inverter circuit operates at a frequency of 50 / 60 Hz, following the AC power grid. The switching of AC voltage within the circuit and the control of the output AC voltage can be controlled by triggering thyristors 301a and power MOS transistors 301b.

[0050] During operation, bridge arms Q1 and Q4 form a pair, and bridge arms Q2 and Q3 form another pair. Both pairs of bridge arms conduct simultaneously, alternating 180° between them. Within a cycle, Q1 and Q4 conduct during the positive half-cycle, and Q2 and Q3 conduct during the negative half-cycle, with the two pairs complementing each other. By modulating the PWM wave of the single-phase inverter circuit, the half-sine wave on the DC bus is inverted into a full sine wave. Software-controlled phase-locked follower flipping ensures that the power quality of the power frequency inverter meets grid-connected specifications.

[0051] The rest of the structure is the same as that of Example 1.

[0052] Example 3

[0053] Reference Figure 1-Figure 7 This is the third embodiment of the present utility model. Different from the previous embodiment, this embodiment provides multiple power supplies that are isolated from each other, solving the problem of electrical safety.

[0054] Specifically, the sampling and protection unit 500 includes a signal processing circuit 501 connected to the primary side and the power frequency side, as well as an AD sampling signal circuit 502 and a hardware comparator circuit 503, both connected to the DSP core processor 100. The sampling sources for the signal processing circuit 501 include a primary side sampling module 501a and a power frequency side grid sampling module 501b. Signal processing is performed by the signal processing circuit 501, and the data is sent to the DSP core processor 100 via the AD sampling signal circuit 502. Some signals are designed with a hardware comparator circuit 503 to implement hardware parameter protection for the system.

[0055] Furthermore, the primary side sampling module 501a includes primary side voltage sampling, primary side current sampling and primary side MOS voltage sampling; the grid sampling module 501b includes DC bus voltage sampling, grid voltage sampling, grid zero-crossing sampling and grid current sampling.

[0056] Preferably, the auxiliary power supply 600 outputs three power supplies, with the photovoltaic-side power supply to the primary-side flyback boost unit 200 and the grid-side power supply to the power-frequency inverter output unit 300 being isolated from each other. These three power supplies from the auxiliary power supply 600 respectively power the system's DSP core processor 100, the flyback drive, and the full-bridge inverter. The photovoltaic and grid-side power supplies are isolated to meet electrical safety requirements.

[0057] The rest of the structure is the same as that of Example 2.

[0058] The DSP core processor 100 controls the device's functions and data exchange. It receives and processes sampling protection signals, connects and controls the primary-side boost voltage, connects and controls the power-frequency inverter output, and connects to Wi-Fi / Bluetooth modules to enable communication between the system and the host photovoltaic cloud platform. The auxiliary power supply is multi-channel and isolated. System protection controls include overvoltage and overcurrent protection, ensuring automatic power disconnection in abnormal situations, thereby reducing electrical risks.

[0059] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, and all of these should be included in the scope of the claims of the present invention.

Claims

1. A micro-inverter supporting a photovoltaic cloud platform system, characterized by: include, A DSP core processor (100) is respectively connected to a primary-side flyback boost unit (200), an industrial frequency inverter output unit (300), a communication unit (400), and a sampling protection unit (500); An auxiliary power supply (600) is connected to the DSP core processor (100), the primary side flyback boost unit (200), and the power frequency inverter output unit (300) respectively; The communication unit (400) is connected and communicated with the photovoltaic cloud platform via wireless signal transmission.

2. The micro-inverter supporting the photovoltaic cloud platform system according to claim 1, characterized in that: The DSP core processor (100) comprises an SPWM control module (101) for controlling the primary side drive, and a PWM control module (102) for controlling the power frequency side.

3. The micro-inverter supporting the photovoltaic cloud platform system according to claim 2, characterized in that: The primary-side flyback boost unit (200) is connected to the SPWM control module (101) and includes at least two sets of parallel-connected flyback drive circuits (201).

4. The micro-inverter supporting the photovoltaic cloud platform system according to claim 3, characterized in that: The industrial frequency inverter output unit (300) is connected to the PWM control module (102), and comprises a full-bridge inverter circuit (301) connected in parallel with the power grid.

5. The micro-inverter supporting the photovoltaic cloud platform system according to claim 4, characterized in that: The flyback drive circuit (201) is provided with a transformer (201a) and a switch tube (201b) for converting voltage into a pulse signal.

6. The micro-inverter supporting the photovoltaic cloud platform system according to claim 5, characterized in that: The full-bridge inverter circuit (301) is provided with a thyristor (301a) and a power MOS tube (301b), and the thyristor (301a) and the power MOS tube (301b) form an inverter bridge structure.

7. The micro-inverter supporting a photovoltaic cloud platform system according to any one of claims 4 to 6, characterized in that: The sampling protection unit (500) comprises a signal processing circuit (501) connected to the primary side and the power frequency side respectively, and an AD sampling signal circuit (502) and a hardware comparator circuit (503) connected to the DSP core processor (100) respectively; The sampling source of the signal processing circuit (501) includes a primary-side sampling module (501a) and a power grid sampling module (501b) on the power frequency side.

8. The micro-inverter supporting the photovoltaic cloud platform system according to claim 7, characterized in that: The primary side sampling module (501a) includes primary side voltage sampling, primary side current sampling and primary side MOS voltage sampling.

9. The micro-inverter supporting the photovoltaic cloud platform system according to claim 8, characterized in that: The power grid sampling module (501b) includes DC bus voltage sampling, power grid voltage sampling, power grid zero-crossing sampling, and power grid current sampling.

10. The micro-inverter supporting the photovoltaic cloud platform system according to claim 9, characterized in that: The auxiliary power supply (600) outputs three power supplies, wherein the photovoltaic side power supply input to the primary side flyback boost unit (200) and the grid side power supply input to the power frequency inverter output unit (300) are isolated from each other.

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