Distributed photovoltaic grid-connected inverter control system

Abstract

The utility model discloses a distributed photovoltaic grid-connected inverter control system, which relates to the technical field of inverter control, charges a storage battery in a quick charging mode in a time-phased manner through an anti-countercurrent voltage stabilizing circuit, and adds a load power detection module and a load voltage and current detection circuit at a load. The load power, the voltage and the current are uploaded to a monitoring system to ensure that the output of the inverter does not exceed the limit value, so that the output power of the photovoltaic power supply is ensured, the countercurrent is effectively avoided, and the energy is saved; current and voltage parameters and power of the storage battery and the load are collected in real time, parameter adjustment and system monitoring are achieved through communication with the intelligent monitoring module, the inverter circuit is controlled through the driving circuit to achieve voltage stabilization control, and it is guaranteed that the output voltage is rapidly kept stable when the system is suddenly loaded or deloaded.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic grid-connected inverter control, and particularly relates to a distributed photovoltaic grid-connected inverter control system. Background Art

[0002] With the optimization of the global energy structure, solar energy, as a clean and renewable new energy, is more and more highly regarded, and photovoltaic power generation is even more highly valued. With the increasing intensification of the energy crisis and the improvement of human environmental protection awareness, the development and utilization of new energy are more and more emphasized by people. And solar energy, as an energy source with inexhaustible supply, high efficiency and no pollution, has been more favored by people recently. Photovoltaic power generation stations are generally used as independent power systems and are applied in remote areas with long operating hours. Photovoltaic power generation technology is one of the development trends of new energy in the world, which requires higher system efficiency, greater reliability and more economy.

[0003] At present, the construction modes of photovoltaic power stations mainly include ground power stations (including desert and mountain photovoltaic power stations), distributed power stations (roofs of industrial parks and public buildings), facility agricultural power stations, multi-energy complementary power stations (fishery-light, water-light, wind-light complementary) and small household photovoltaic power stations, etc. According to the application forms of photovoltaic power stations, the development of photovoltaic inverters is relatively rapid, and different inverter solutions have also emerged, namely centralized, string-type and centralized-distributed.

[0004] The domestic demand for electricity is increasing, but the domestic power demand management is still at a relatively low level. In order to achieve scientific, orderly and energy-saving electricity use, improve the efficiency of electricity use, and achieve the purpose of energy conservation and environmental protection, the national power department has introduced a stepped electricity price strategy and adopted peak-valley electricity prices to regulate the electricity consumption behavior of power users.

[0005] Solar energy is an ideal renewable energy. The most promising in the future is the solar photovoltaic power generation system. Its development and utilization is an effective way to solve problems such as energy shortage, environmental pollution and greenhouse effect, and it is an ideal alternative energy for humans. Moreover, the solar distributed power generation system is the development trend of future household and commercial power supply. While meeting its own electricity demand, it can also be connected to the main grid and sell the surplus electricity generated to the power company. Therefore, with the development of solar power generation technology and the decline of the cost of photovoltaic cells, the development and utilization of solar energy will surely become one of the important energy sources. Content of the Utility Model

[0006] The technical problem to be solved by the present utility model is to provide a distributed photovoltaic grid-connected inverter control system in view of the deficiencies in the background technology. Through an anti-counterflow voltage stabilization circuit, it uses a fast charging method to charge the storage battery in segments. A load power detection module and a load voltage and current detection circuit are added at the load, and the load power, voltage, and current are uploaded to the monitoring system to ensure that the inverter output does not exceed the limit value, thereby ensuring the output power of the photovoltaic power source, effectively avoiding counterflow, and saving energy.

[0007] The present utility model adopts the following technical solutions to solve the above technical problems:

[0008] A distributed photovoltaic grid-connected inverter control system includes a solar panel, an anti-counterflow voltage stabilization circuit, a storage battery, an inverter, a transformer, a filter circuit, a load, a load output voltage and current sampling module, a load power detection module, a power supply voltage and current detection circuit, a drive circuit, a controller module, a display module, a clock module, and a memory module;

[0009] The signal output end of the solar panel is connected to the signal input end of the storage battery through the anti-counterflow voltage stabilization circuit. The signal output end of the storage battery is connected to the signal input end of the inverter. The signal output end of the inverter is connected to the signal input end of the transformer. The signal output end of the transformer is connected to the signal input end of the filter circuit. The signal output end of the filter circuit is connected to the load;

[0010] Among them, the load output voltage and current sampling module and the load power detection module are respectively connected to the load for real-time detection of the output voltage, current, and power of the load. The power supply voltage and current detection circuit is connected to the storage battery for real-time detection of the voltage and current parameters of the storage battery. The controller module is respectively connected to the load through the load output voltage and current sampling module and the load power detection module. The controller module is connected to the inverter through the drive circuit. The controller module is connected to the storage battery through the power supply voltage and current detection circuit. The display module, the clock module, and the memory module are respectively connected to the controller module.

[0011] As a further preferred solution of the control system of the distributed photovoltaic grid-connected inverter of the present utility model, the anti-counterflow voltage stabilizing circuit includes a voltage input Vin terminal, a capacitor C1, a capacitor C2, a chip LM2596, an inductor L1, a diode D3, a diode D4, and a voltage output Vout terminal. The voltage input Vin terminal is respectively connected to one end of the capacitor C1 and the +VIN pin of the chip LM2596. The other end of the capacitor C1 is grounded. The GND pin of the chip LM2596 is grounded. The ON / OFF pin of the chip LM2596 is grounded. The OUTPUT pin of the chip LM2596 is respectively connected to one end of the inductor L1 and the cathode of the diode D3. The FEEDBACK pin of the chip LM2596 is respectively connected to the other end of the inductor L1, the anode of the diode D4, and one end of the capacitor C2. The other end of the capacitor C2 is grounded. The anode of the diode D3 is grounded. The cathode of the diode D4 is connected to the voltage output Vout terminal.

[0012] As a further preferred solution of the control system of the distributed photovoltaic grid-connected inverter of the present utility model, the solar

[0013] panel selects an 18V 330W foldable photovoltaic panel.

[0014] As a further preferred solution of the control system of the distributed photovoltaic grid-connected inverter of the present utility model, the transformer adopts a power frequency transformer.

[0015] As a further preferred solution of the control system of the distributed photovoltaic grid-connected inverter of the present utility model, the chip model of the controller module is 68HC908MR16.

[0016] As a further preferred solution of the control system of the distributed photovoltaic grid-connected inverter of the present utility model, the power supply voltage and current detection circuit adopts a Hall sensor.

[0017] As a further preferred solution of the control system of the distributed photovoltaic grid-connected inverter of the present utility model, the clock module includes a clock chip DS3231, a capacitor C4, a resistor R25, a resistor R26, a resistor R27, a resistor R28. The VCC terminal is respectively connected to one end of the resistor R25 and one end of the resistor R26. The other end of the resistor R25 is connected to the SDA terminal of the clock chip DS3231. The other end of the resistor R26 is connected to the SCL terminal of the clock chip DS3231. The VDD terminal is respectively connected to one end of the resistor R27, one end of the resistor R28, one end of the capacitor C4, and the 2 port of the clock chip DS3231. The other end of the resistor R27 is connected to the 1 port of the clock chip DS3231. The other end of the resistor R28 is connected to the 3 port of the clock chip DS3231. The other end of the capacitor C4 is grounded.

[0018] As a further preferred solution of the distributed photovoltaic grid-connected inverter control system of the present utility model, the memory module adopts a DDR3 memory.

[0019] As a further preferred solution of the distributed photovoltaic grid-connected inverter control system of the present utility model, the display module adopts a digital display screen.

[0020] Compared with the prior art by adopting the above technical solutions, the present utility model has the following technical effects:

[0021] A distributed photovoltaic grid-connected inverter control system of the present utility model includes a solar panel, an anti-counterflow voltage stabilizing circuit, a storage battery, an inverter, a transformer, a filtering circuit, a load, a load output voltage and current sampling module, a load power detection module, a power supply voltage and current detection circuit, a driving circuit, a controller module, a display module, a clock module, and a memory module; through the anti-counterflow voltage stabilizing circuit, it charges the storage battery in a fast charging manner in different time periods, adds a load power detection module and a load voltage and current detection circuit at the load, uploads the load power, voltage and current to the monitoring system to ensure that the output of the inverter does not exceed the limit value, thereby ensuring the output power of the photovoltaic power supply, effectively avoiding counterflow, and saving energy; at the same time, it real-time collects the current, voltage parameters and power of the storage battery and the load, and realizes parameter adjustment and system monitoring by communicating with the intelligent monitoring module, and then controls the inverter circuit through the driving circuit to achieve voltage stabilizing control, thereby ensuring that the output voltage quickly remains stable when the system is suddenly loaded or unloaded. Description of the Drawings

[0022] Figure 1 is the overall structural schematic diagram of a distributed photovoltaic grid-connected inverter control system of the present utility model;

[0023] Figure 2 is the circuit diagram of the anti-counterflow voltage stabilizing circuit of the present utility model;

[0024] Figure 3 is the circuit diagram of the clock module of the present utility model. Detailed Embodiments

[0025] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model:

[0026] A distributed photovoltaic grid-connected inverter control system, as shown in Figure 1, includes a solar panel, an anti-backflow voltage stabilizing circuit, a storage battery, an inverter, a transformer, a filtering circuit, a load, a load output voltage and current sampling module, a load power detection module, a power supply voltage and current detection circuit, a driving circuit, a controller module, a display module, a clock module, and a memory module;

[0027] The signal output terminal of the solar panel is connected to the signal input terminal of the storage battery through the anti-backflow voltage stabilizing circuit. The signal output terminal of the storage battery is connected to the signal input terminal of the inverter. The signal output terminal of the inverter is connected to the signal input terminal of the transformer. The signal output terminal of the transformer is connected to the signal input terminal of the filtering circuit. The signal output terminal of the filtering circuit is connected to the load;

[0028] Among them, the load output voltage and current sampling module and the load power detection module are respectively connected to the load for real-time detection of the output voltage, current and power of the load. The power supply voltage and current detection circuit is connected to the storage battery for real-time detection of the voltage and current parameters of the storage battery. The controller module is respectively connected to the load through the load output voltage and current sampling module and the load power detection module. The controller module is connected to the inverter through the driving circuit. The controller module is connected to the storage battery through the power supply voltage and current detection circuit. The display module, the clock module and the memory module are respectively connected to the controller module.

[0029] It charges the storage battery in a fast charging mode through the anti-backflow voltage stabilizing circuit in different time periods. A load power detection module and a load voltage and current detection circuit are added at the load to upload the load power, voltage and current to the monitoring system to ensure that the inverter output does not exceed the limit value, thereby ensuring the output power of the photovoltaic power supply, effectively avoiding backflow and saving energy. At the same time, it real-time collects the current, voltage parameters and power of the storage battery and the load, and realizes parameter adjustment and system monitoring through communication with the intelligent monitoring module, and then controls the inverter circuit through the driving circuit to achieve voltage stabilizing control, so as to ensure that the output voltage quickly remains stable when the system is suddenly loaded or unloaded.

[0030] Such as Figure 2As shown in the figure, the anti-backflow voltage stabilizing circuit includes a voltage input Vin terminal, a capacitor C1, a capacitor C2, a chip LM2596, an inductor L1, a diode D3, a diode D4, and a voltage output Vout terminal. The voltage input Vin terminal is respectively connected to one end of the capacitor C1 and the +VIN pin of the chip LM2596. The other end of the capacitor C1 is grounded. The GND pin of the chip LM2596 is grounded. The ON / OFF pin of the chip LM2596 is grounded. The OUTPUT pin of the chip LM2596 is respectively connected to one end of the inductor L1 and the cathode of the diode D3. The FEEDBACK pin of the chip LM2596 is respectively connected to the other end of the inductor L1, the anode of the diode D4, and one end of the capacitor C2. The other end of the capacitor C2 is grounded. The anode of the diode D3 is grounded. The cathode of the diode D4 is connected to the voltage output Vout terminal.

[0031] The utility model uses an anti-backflow voltage stabilizing circuit and adopts a fast charging method to charge two lead-crystal batteries with a DC voltage of 12V and a capacity of 75Ah in different time periods. In order to achieve fast charging and consider the conversion efficiency of the solar panel, an 18V 330W folding photovoltaic panel is selected. When each battery is fully charged, it can provide 0.9 kilowatt-hours of electrical energy. In order to extend the battery life, a 10% remaining power is set.

[0032] The inverter of the utility model is encapsulated in a metal shell, which is convenient for overall installation on the radiator and helps to work in high-power output occasions for a long time. The working voltage of PB50 is from ±30V to ±100V, and a continuous DC current output of 2A can be obtained. It has voltage and current gain, a high voltage change rate, and can reach a working frequency of 160KHz, and the current accuracy can reach 12mA.

[0033] Preferably, the transformer adopts a power frequency transformer.

[0034] Preferably, the chip model of the controller module is 68HC908MR16. The chip model of the controller module is 68HC908MR16. The 68HC908MR16 single-chip microcomputer is a low-cost and high-performance eight-bit single-chip microcomputer. It has 32k bytes of erasable on-chip flash memory FLASH, 768 bytes of RAM, which is completely sufficient for this system. It has a clock generator module that can select an external crystal oscillator clock or an internal phase-locked loop clock. The internal phase-locked loop clock selected by this system can generate an accurate 8MHz internal bus frequency, thus ensuring the frequency accuracy of the system. It has a programmable AD clock, and the AD conversion time is only 2μs at the fastest, which can minimize the execution time of the interrupt program. It has an SCI serial communication interface, which can work in full-duplex or half-duplex mode and can reliably complete serial communication with the external keyboard monitoring system in this system.

[0035] Preferably, the power supply voltage and current detection circuit uses a Hall sensor.

[0036] As Figure 3 shown, the clock module includes a clock chip DS3231, a capacitor C4, a resistor R25, a resistor R26, a resistor R27, and a resistor R28. The VCC terminal is respectively connected to one end of the resistor R25 and one end of the resistor R26. The other end of the resistor R25 is connected to the SDA terminal of the clock chip DS3231. The other end of the resistor R26 is connected to the SCL terminal of the clock chip DS3231. The VDD terminal is respectively connected to one end of the resistor R27, one end of the resistor R28, one end of the capacitor C4, and the 2 port of the clock chip DS3231. The other end of the resistor R27 is connected to the 1 port of the clock chip DS3231. The other end of the resistor R28 is connected to the 3 port of the clock chip DS3231. The other end of the capacitor C4 is grounded.

[0037] The clock circuit is designed and implemented by using a low-cost and high-precision real-time clock chip DS3231. The register address of DS3231 is 00h to 12h. It obtains clock and date information by reading appropriate register bytes. It obtains clock and calendar information by writing appropriate register bytes. It sets or initializes clock and calendar data by writing appropriate register bytes.

[0038] Preferably, the memory module uses a DDR3 memory.

[0039] Preferably, the display module uses a digital display screen.

[0040] Those skilled in the art of this technology can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used here have the same meaning as the general understanding of those of ordinary skill in the field to which this utility model belongs. It should also be understood that terms defined in a general dictionary, such as those, should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless defined as here.

[0041] The above embodiments are only used to illustrate the technical idea of this utility model, and the protection scope of this utility model cannot be limited thereby. Any changes made on the basis of the technical solution according to the technical idea proposed by this utility model fall within the protection scope of this utility model. The above has made a detailed description of the embodiments of this utility model, but this utility model is not limited to the above embodiments. Various changes can be made without departing from the gist of this utility model within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A distributed photovoltaic grid-connected inverter control system, characterized in that: It includes solar panels, anti-reverse current voltage stabilization circuits, batteries, inverters, transformers, filter circuits, loads, load output voltage and current sampling modules, load power detection modules, power supply voltage and current detection circuits, drive circuits, controller modules, display modules, clock modules, and memory modules; The signal output end of the solar panel is connected to the signal input end of the battery through an anti-backflow voltage stabilizing circuit, the signal output end of the battery is connected to the signal input end of the inverter, the signal output end of the inverter is connected to the signal input end of the transformer, the signal output end of the transformer is connected to the signal input end of the filter circuit, and the signal output end of the filter circuit is connected to the load; Among them, the load output voltage and current sampling module and the load power detection module are respectively connected to the load for real-time detection of the output voltage, current and power of the load; the power supply voltage and current detection circuit is connected to the battery for real-time detection of the voltage and current parameters of the battery; the controller module is connected to the load through the load output voltage and current sampling module and the load power detection module, the controller module is connected to the inverter through the drive circuit, and the controller module is connected to the battery through the power supply voltage and current detection circuit; the display module, the clock module, and the memory module are respectively connected to the controller module.

2. A distributed photovoltaic grid-connected inverter control system according to claim 1, characterized in that: The anti-reverse current voltage stabilizing circuit includes a voltage input Vin terminal, a capacitor C1, a capacitor C2, a chip LM2596, an inductor L1, a diode D3, a diode D4, and a voltage output Vout terminal. The voltage input Vin terminal is respectively connected to one end of the capacitor C1 and a +VIN pin of the chip LM2596, the other end of the capacitor C1 is grounded, the GND pin of the chip LM2596 is grounded, the ON / OFF pin of the chip LM2596 is grounded, the OUTPUT pin of the chip LM2596 is respectively connected to one end of the inductor L1 and the cathode of the diode D3, the FEEDBACK pin of the chip LM2596 is respectively connected to the other end of the inductor L1, the anode of the diode D4, and one end of the capacitor C2, the other end of the capacitor C2 is grounded, the anode of the diode D3 is grounded, and the cathode of the diode D4 is connected to the voltage output Vout terminal.

3. A distributed photovoltaic grid-connected inverter control system according to claim 1, characterized in that: The solar panel is a 18V 330W foldable photovoltaic panel.

4. A distributed photovoltaic grid-connected inverter control system according to claim 1, characterized in that: The transformer is an industrial frequency transformer.

5. A distributed photovoltaic grid-connected inverter control system according to claim 1, characterized in that: The chip model of the controller module is 68HC908MR16.

6. A distributed photovoltaic grid-connected inverter control system according to claim 1, characterized in that: The power supply voltage and current detection circuit adopts a Hall sensor.

7. A distributed photovoltaic grid-connected inverter control system according to claim 1, characterized in that: The clock module includes a clock chip DS3231, a capacitor C4, a resistor R25, a resistor R26, a resistor R27, and a resistor R28. The VCC end is respectively connected to one end of the resistor R25 and one end of the resistor R26, the other end of the resistor R25 is connected to the SDA end of the clock chip DS3231, the other end of the resistor R26 is connected to the SCL end of the clock chip DS3231, the VDD end is respectively connected to one end of the resistor R27, one end of the resistor R28, one end of the capacitor C4, and port 2 of the clock chip DS3231, the other end of the resistor R27 is connected to port 1 of the clock chip DS3231, the other end of the resistor R28 is connected to port 3 of the clock chip DS3231, and the other end of the capacitor C4 is grounded.

8. A distributed photovoltaic grid-connected inverter control system according to claim 1, characterized in that: The memory module adopts DDR3 memory.

9. A distributed photovoltaic grid-connected inverter control system according to claim 1, characterized in that: The display module adopts a digital display screen.

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