CN102088257A - Solar electricity generation system and intelligent storage control method thereof - Google Patents

Abstract

The invention relates to a solar power generation system and an intelligent storage control method thereof. The solar power generation system includes a string of solar battery components, and an intelligent storage controller is installed at the output end of each string of solar battery components, and the intelligent storage controller is connected to a power storage device. The components output electric energy through the intelligent storage controller. The power storage device and the solar battery module are controlled by the intelligent storage controller, and output stable electric energy separately or simultaneously. The intelligent storage controller sets the charging according to the irradiation resources of the installation site , Discharge and power output ratio. The present invention combines an intelligent storage controller with a string of solar battery components, so that each string of solar battery components is equipped with an intelligent storage controller, which can adjust the output electrical performance characteristics of the corresponding component string, and provide a fixed and constant power to the DC load or the power grid. At the same time, the output power of the module string can also be flexibly controlled, making the module string unit more intelligent and the power output more stable and reliable.

Description

A solar power generation system and its intelligent storage control method

technical field

The invention relates to a solar power generation system and an intelligent storage control method thereof.

Background technique

The basic working principle of the solar photovoltaic power supply system is to store the electric energy generated by the solar cell components in the storage battery (that is, charging) under the sunlight, or directly supply power to the load when the load demand is met; if the sunshine is insufficient or in the At night, the battery supplies power to the DC load, or the inverter supplies power to the AC load (that is, discharge); at the same time, the AC power after the inverter can also be directly transmitted to the local power grid.

Since the current ratio of photovoltaic power generation to the capacity of the entire grid is very small, photovoltaic power generation has little impact on the power grid, and even has a partial peak-shaving effect (usually during the day when electricity consumption peaks). When photovoltaics develop on a large scale, in some areas, they may become the main source of electricity for the grid. At this time, how to balance the huge difference between photovoltaic power generation during the day and night will become a very difficult problem. At the same time, when the solar cell module string directly supplies power to the DC load, issues such as the stability of the power supply must also be considered.

Contents of the invention

The technical problem to be solved by the present invention is to provide a solar power generation system, which can reduce the impact of the solar battery module string on the DC load and the power grid, reduce fluctuations in current, voltage, power, etc., and improve power quality.

The technical solution adopted by the present invention to solve the technical problem is: a solar power generation system, including a string of solar cell components, an intelligent storage controller is installed at the output end of the string of solar cell components, the intelligent storage controller is connected with a power storage device, and the solar cell The component strings output electric energy through the intelligent storage controller. The power storage device and the solar battery module string are controlled by the intelligent storage controller, and output stable electric energy separately or simultaneously. The intelligent storage controller is based on the radiation resources of the installation site Set the charging, discharging and power output ratio.

The intelligent storage controller includes a main control unit and a PWM charge and discharge control unit. The main control unit is connected to the output terminal of the solar battery module string and the PWM charge and discharge control unit. The PWM charge and discharge control unit is connected to the power storage device. The main control unit outputs PWM The signal is used to control the PWM charge and discharge control unit to realize the charge and discharge control of the battery.

The intelligent storage control method of the intelligent storage controller is: when the output electric energy of the solar battery module string is greater than the set value, the intelligent storage controller stores the excess electric energy in the power storage device; when the output electric energy of the solar battery module string is less than the set value Fixed value, the intelligent storage controller controls the energy storage device to output electric energy to the outside at the same time, maintaining a stable electric energy output.

It is further defined that only when the electric energy output by the solar battery module string is less than the set value and the output electric energy drop setting is greater than the set speed, the intelligent storage controller controls the energy storage device to output electric energy at the same time to maintain stable electric energy output.

The radiation intensity of the environment is directly proportional to the output electric energy of the components, so the intelligent storage control method of the intelligent storage controller can also be: when the radiation intensity is greater than the set value, the intelligent storage controller will output electric energy normally, Charge the excess electric energy to the power storage device. When the radiation intensity is lower than the set value and the falling speed is greater than the set speed, the intelligent storage controller controls the solar battery module string and the power storage device to output electric energy at the same time to maintain a stable power output .

It is further defined that when the irradiation intensity is lower than the set value and the falling speed is greater than the set speed, the intelligent storage controller controls the solar battery module string and the power storage device to output electric energy at the same time to maintain a stable electric energy output.

The setting speed of the falling speed of the radiation intensity is any value between 10W/m2/s and 100W/m2/s.

The beneficial effect of the present invention is that: the present invention combines the intelligent storage controller with the solar cell assembly string, so that each string of solar cell assembly is equipped with an intelligent storage controller, which can adjust the output electrical performance characteristics of the corresponding assembly string, and provide direct current load Or the power grid provides a fixed amount of electricity. At the same time, the output power of the module string can also be flexibly controlled to make the module string unit more intelligent and the power output more stable and reliable.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the present invention is further described;

Fig. 1 is a structural schematic diagram of a solar power generation system;

Fig. 2 is a schematic structural diagram of an intelligent storage controller;

Fig. 3 is a working principle diagram of an intelligent storage controller;

Detailed ways

As shown in Figure 1, a solar power generation system installs an intelligent storage controller at the output end of each solar cell module string, integrates the power storage device and the intelligent storage controller, and controls the storage and output of electric energy. The solar battery module string can set the charging, discharging and power output ratio according to the radiation resource conditions of the installation site. The components can be composed of crystalline silicon solar cells, III-V solar cells, and various thin-film solar cells. The storage device can use lead-acid maintenance-free accumulators or colloidal batteries. The configuration ratio of the storage battery and the solar battery module string can be adjusted according to the needs of the application field. The intelligent storage controller can be applied to grid-connected photovoltaic systems and off-grid photovoltaic systems, including building-integrated photovoltaics and photovoltaic power plants. The configuration ratio of the storage battery and the solar battery module string can be adjusted according to the needs of the application field.

The intelligent storage control method of the intelligent storage controller, when the radiation intensity is greater than the set value, the intelligent storage controller not only outputs electric energy normally, but also charges the excess electric energy to the storage device; when the radiation intensity is lower than the set value value and the falling speed is greater than the set speed, the intelligent storage controller controls the solar battery module string and the power storage device to output electric energy at the same time to make up for the missing electric energy and maintain a stable electric energy output.

The power of the module is usually defined as the standard test condition (irradiation 1000W/m2, temperature 25 degrees Celsius, spectrum AM1.5), for example, the annual radiation intensity of a photovoltaic system installation site with 1000Wp (component peak power) is greater than 800W/m2 and less than 50 hours, and no more than 1 hour per day, the intelligent storage controller can set the power of the module string to be greater than 800Wp (at this time, the radiation intensity is greater than 800W/m2), and the excess part will not supply power to the outside (inverter, etc.), which is used for Battery charging; when the irradiance (suddenly cloudy) drops sharply, the irradiance is less than 800W/m2 and the speed is greater than 10W/m2/s (or 20W/m2/s or 50W/m2/s or 100W/m2/s, the value Can be set), the intelligent storage controller sets the power storage device and supplies power to the outside at the same time, and the output power of the entire solar cell module string remains stable. Through the above settings, the photovoltaic system can reduce 200Wp inverters and other power distribution equipment, saving 20% of the cost of power distribution equipment, while maintaining the stability and reliability of power output, and reducing the impact of radiation intensity fluctuations on the power grid.

The environmental radiation intensity is directly proportional to the output power of the module, so the smart storage control method of the smart storage controller can also be: when the output power of the solar cell module string is greater than the set value, the smart storage controller will store the excess power In the power storage device, when the electric energy output by the solar battery module string is less than the set value and the output power drop setting is greater than the set speed, the intelligent storage controller controls the energy storage device to output electric energy at the same time to make up for the missing electric energy. Maintain stable power output.

As shown in Figure 2, the intelligent storage controller includes a main control unit and a PWM charge and discharge control unit, the main control unit is connected to the output end of the solar battery module string and the PWM charge and discharge control unit, and the PWM charge and discharge control unit is connected to the storage device , the main control unit outputs a PWM signal to control the PWM charge and discharge control unit to realize the charge and discharge control of the storage battery. The PWM charge and discharge control unit of the intelligent storage controller adopts a Buck conversion circuit, and the main control unit adopts a single-chip microcomputer STC89C52 as a control chip. Processing, after processing the output PWM signal to control the duty cycle of the switch tube of the Buck circuit to realize the charge and discharge control of the battery. The single-chip microcomputer has various functional modules such as display and protection alarm.

As shown in Figures 2 and 3, the specific implementation of the present invention is: the output electric energy of the solar cell is related to the irradiance, and the fluctuation range of the current value is determined according to the local annual irradiance in the actual installation environment. Set the reference current value within the range. If the output current is greater than the set reference current value, the single-chip microcomputer outputs a PWM charging signal to store excess electric energy in the electric storage device. When there is a sudden change (such as the radiation intensity becomes smaller), if the output current is less than the set reference current value and the falling speed is greater than the set speed, the single-chip microcomputer outputs a PWM discharge signal, and the power storage device supplies corresponding power to the power grid , to make up for the lack of electric energy, and at this time the DC load or grid is not impacted by electric energy, and still receives stable electric energy.

Claims (7)

1. A solar power generation system, comprising a string of solar cell components, characterized in that: an intelligent storage controller is installed at the output end of the string of solar cell components, the intelligent storage controller is connected with a power storage device, and the string of solar cell components passes through an intelligent The storage controller outputs electric energy to the outside. The power storage device and the solar cell module string are controlled by the intelligent storage controller, and output stable electric energy separately or simultaneously. The intelligent storage controller sets the charging and discharging according to the irradiation resources of the installation site. Proportional to power output. 2. The solar power generation system according to claim 1, characterized in that: the intelligent storage controller includes a main control unit and a PWM charge and discharge control unit, the main control unit and the output terminal of the solar battery assembly string, the PWM charge and discharge The control unit is connected, the PWM charge and discharge control unit is connected with the power storage device, and the main control unit outputs a PWM signal to control the PWM charge and discharge control unit to realize the charge and discharge control of the storage battery. 3. The intelligent storage control method of the intelligent storage controller according to claim 1, characterized in that: when the output electric energy of the solar battery module string is greater than the set value, the intelligent storage controller stores the excess electric energy in the electric storage device , when the electric energy output by the solar battery module string is less than the set value, the intelligent storage controller controls the energy storage device to output electric energy at the same time to maintain the stable electric energy output. 4. The intelligent storage control method of the intelligent storage controller according to claim 3, characterized in that: when the electric energy output by the solar cell module string is less than the set value and the output electric energy drop setting is greater than the set speed, the intelligent storage control The controller controls the energy storage device to output electric energy to the outside at the same time, so as to maintain a stable electric energy output. 5. The intelligent storage control method of the intelligent storage controller according to claim 1, characterized in that: when the irradiation intensity is greater than the set value, the intelligent storage controller will output the excess electric energy Charging the storage device, when the radiation intensity is less than the set value and the falling speed is greater than the set speed, the intelligent storage controller controls the solar battery module string and the storage device to output electric energy at the same time to maintain a stable power output. 6. The intelligent storage control method of the intelligent storage controller according to claim 5, characterized in that: when the radiation intensity is less than the set value and the falling speed is greater than the set speed, the intelligent storage controller controls the solar cell module string and The power storage device outputs electric energy to the outside at the same time to maintain a stable electric energy output. 7. The intelligent storage control method of the intelligent storage controller according to claim 6, characterized in that: the set speed of the radiation intensity decrease rate is any value between 10W/m2/s-100W/m2/s.

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