CN104135800A - Solar LED street lamp control system and method based on photovoltaic power generation - Google Patents

Abstract

The present invention relates to a solar LED street lamp control system based on photovoltaic power generation and its method. , a temperature sensor and an LED street lamp, the LED street lamp controller is connected with an illuminance sensor, a solar panel, a first switch tube, a second switch tube, and a temperature sensor, and the battery is connected with the first switch tube and the second switch tube; The method includes a storage battery charging control method and an LED street lamp driving control method, and performs charging control and LED driving control on the storage battery according to the voltage and temperature parameters of the storage battery collected in real time. The present invention constitutes a photovoltaic power generation lighting system through an LED street lamp controller. The controller controls the charge and discharge of the battery, the brightness of the LED lamp, etc. by monitoring the solar panel, the battery, and the intensity of light, so as to achieve the purpose of safe and stable operation of the entire system.

Description

A solar LED street lamp control system and method based on photovoltaic power generation

technical field

The invention belongs to the technical field of photovoltaic power generation, in particular to a solar LED street lamp control system and method based on photovoltaic power generation.

Background technique

As an ideal clean energy, solar energy is rapidly being widely used. As a solid-state light source, LED has the characteristics of long life and low energy consumption, and is a green light source. With the technology of high-power LED driving becoming more and more mature, LED has been widely promoted and applied in the field of lighting. Solar panels directly convert solar energy into electrical energy, and with battery components, LED street lights can meet the lighting needs without mains electricity. This combination of solar energy and LEDs is applied to the field of street lighting, which can save a lot of cable costs and save a lot of energy.

Since solar energy is relatively restricted by weather factors, the distribution density of sunlight is small, and the light receiving time and intensity are random and intermittent. To ensure the stability of the output voltage of solar cells, batteries must be used. When there is sunlight during the day, it will emit The electric energy stored in the battery pack is discharged to the load LED at night. If there is continuous rainy weather, the battery capacity is required to be large, and the greater the capacity of the solar battery pack, the higher the cost. Therefore, how to reasonably control the charging and discharging of the battery and the brightness of the LED lights to ensure the safe and stable operation of the system is currently the problems that urgently need to be resolved.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a solar LED street lamp control system and method based on photovoltaic power generation with reasonable design, energy saving, environmental protection, safety and stability.

The present invention solves its technical problem and realizes by taking the following technical solutions:

A solar LED street lamp control system based on photovoltaic power generation, including an LED street lamp controller, a solar panel, a first switch tube, a second switch tube, a battery, and an LED street lamp. The LED street lamp controller collects light information through an illuminance sensor, and the LED street lamp The controller is connected to the solar panel to collect the voltage of the solar panel. The LED street lamp controller is connected to the battery through the first switch tube and the second switch tube to control the charge and discharge of the battery. The LED street lamp controller collects the voltage through the voltage The module and the temperature sensor are connected with the battery to realize battery voltage and temperature collection. The input end of the battery is connected to the solar panel through the first switch tube, and the output end of the battery is connected to the LED street lamp through the second switch tube to supply power for it. .

Moreover, the described LED street lamp controller includes a CPU unit, a power supply and reset module, a voltage acquisition module, a temperature acquisition module, an illuminance sensor and an output control fast module, and the CPU unit is respectively connected with the power supply and reset module, the voltage acquisition module, and the temperature acquisition module. , an illuminance sensor, and an output control fast module, and the output control module controls the connection with the battery and the LED street lamp to realize the functions of charging the battery and driving the LED street lamp.

Moreover, the solar panel adopts polycrystalline silicon solar panel CETC48.150; the storage battery adopts lead-acid storage battery LCX12120ST; the first switch tube and the second switch tube use IRF530N; the temperature sensor adopts programmable Temperature sensor DS18B20; the light sensor uses TSL256x.

Moreover, the CPU unit adopts ATxmega256A3BU chip, and the CPU unit is connected with the temperature acquisition module and the illuminance sensor through the I2C bus connection mode. .

A control method for a solar LED street lamp control system based on photovoltaic power generation, including a battery charging control method and an LED street lamp drive control method, wherein:

The storage battery charging control method includes the following steps:

Step 1: The CPU unit judges whether it is daytime according to the illuminance of the illuminance sensor, if it is, it executes charging the battery, otherwise it ends;

Step 2: The CPU unit performs temperature compensation on the battery according to the ambient temperature of the battery collected by the temperature sensor;

Step 3: Real-time detection of battery voltage and temperature compensation during the charging process, high duty cycle charging is used from the 11.2V over-undervoltage point to the 13.6V floating charge point, and low duty cycle is used between the floating charge point 13.6V～14.4V Float charge; between 14.4V and 14.8V, use ultra-low duty cycle float charge, and when it reaches 14.8V, the charge will be terminated;

The LED street lamp drive control method includes the following steps:

Step 1: The CPU unit judges whether it is night according to the illuminance of the illuminance sensor, and if it is, execute the driving of the LED street lamp, otherwise it ends;

Step 2: The CPU unit performs temperature compensation on the battery according to the ambient temperature of the battery collected by the temperature sensor;

Step 3: When the battery voltage is higher than 13.6V, drive the LED street lamp with a current lower than 25% of the rated current; when the battery voltage is between 12.5V and 13.6V, drive the LED street lamp with a current lower than 20% of the rated current; When the battery voltage is between 12V and 12.5V, drive the LED street lamp with a current 15% lower than the rated current; when the battery voltage is lower than 12V, stop driving the LED street lamp.

Moreover, the voltage obtained after performing temperature compensation on the storage battery in step 2 is:

Ue=U+(t-25)f

U is the actual measured voltage, t is the ambient temperature measured by the temperature sensor, f is the temperature compensation coefficient, and Ue is the voltage value after compensation.

Advantage and positive effect of the present invention are:

1. The present invention constitutes a photovoltaic power generation lighting system through an LED street lamp controller. The controller controls the charging and discharging of the battery, the brightness of the LED lamp, etc. by monitoring the solar panel, the battery, and the intensity of light, etc., so as to achieve safe and stable operation of the entire system. Purpose.

2. The present invention integrates the functions of turning on the light by light control, turning off the light by light control, and overcharging and overdischarging protection functions, with stable and reliable performance.

3. The present invention judges whether it is day or night according to the illuminance sensor, eliminating the need for a clock chip, no need for remote time adjustment or GPS time adjustment, saving costs, and increasing the intelligence of solar LED street lamp control.

4. The present invention does not need power transmission lines, does not need to consume grid power, and can use the inexhaustible solar energy to provide stable and reliable lighting once and for all with a one-time investment that is roughly equivalent to conventional street lamps. Economic benefits, avoiding the problems of high construction cost of street lamp power supply lines and high power consumption on the lines caused by the need for buried cable power supply for conventional street lamps, and can meet the lighting needs of remote areas and offshore operating platforms without mains power.

Description of drawings

Fig. 1 is the system connection schematic diagram of the present invention;

Fig. 2 is the circuit block diagram of LED street lamp controller of the present invention;

Fig. 3 is the battery charging control flowchart of the present invention;

Fig. 4 is a flow chart of LED street lamp drive control in the present invention.

Detailed ways

Embodiments of the present invention are described in further detail below in conjunction with the accompanying drawings:

A solar LED street lamp control system based on photovoltaic power generation, as shown in Figure 1, includes an LED street lamp controller, a solar panel, a first switching tube (switching tube 1), a second switching tube (switching tube 2), a battery and LED street lamp, the LED street lamp controller collects light information through the illuminance sensor, the LED street lamp controller is connected with the solar panel to collect the voltage of the solar panel, the LED street lamp controller is connected with the battery through the first switch tube and the second switch tube The connection is used to control the charge and discharge of the battery. The LED street lamp controller is connected to the battery through the voltage acquisition module and the temperature sensor to realize the battery voltage and temperature acquisition. The input end of the battery is connected to the solar panel through the first switch tube. The battery The output end of the LED street lamp is connected to supply power for it through the second switch tube. In this embodiment, the solar panel adopts polycrystalline silicon solar panel CETC48.150, and its peak voltage is 18.65V and peak current is 8.8A under the condition of 1000 illuminance and 25°C; the battery adopts lead-acid battery LCX12120ST, and the battery capacity is 45AH ; AC-DC adopts general modular AC-DC power supply, its output voltage level is +12V, current is 25A; switch tube adopts IRF530N, its breakdown voltage VDSS is 100V, which can meet the needs of photovoltaic power generation system.

As shown in Figure 2, the LED street lamp controller includes a CPU unit, a power supply and reset module, a voltage acquisition module, a temperature acquisition module, an illuminance sensor, and an output control fast module. The module, the illuminance sensor, and the output control fast module are connected, and the output control module controls the connection with the battery and the LED street lamp to realize the functions of charging the battery and driving the LED street lamp. In this embodiment, the CPU unit adopts the ATxmega256A3BU chip of ATMEL Company. This chip has a maximum operating frequency of 32MHZ, 256+8K on-chip programmable flash, and 16K SRAM. It also has rich peripheral interfaces, which is convenient for expanding various hardware circuit. The temperature acquisition sensor uses a programmable temperature sensor DS18B20 for temperature detection, which has the characteristics of strong anti-interference ability, high temperature acquisition accuracy, and does not require complicated conditioning circuits and AD conversion circuits. The connection between DS18B20 and ATxmega256A3BU is I2C bus. The illuminance sensor adopts TSL256x. The access of the TSL256x follows the standard SMBus and I2C protocols, which makes the chip software and hardware design very simple. Although the read and write timings of the two protocols are very similar, there are still differences. In this embodiment, the I2C bus is used to connect with the ATxmega256A3BU.

A method for controlling LED street lamps based on photovoltaic power generation, including a battery charging control method and an LED street lamp driving control method. Instructions are given below:

The battery charging control method is that the CPU unit controls the battery charging according to the real-time monitoring of the illuminance, the voltage of the solar panel, the battery voltage and the temperature of the battery, as shown in Figure 3, specifically including the following steps:

Step 1: The CPU unit judges whether it is daytime according to the illuminance of the illuminance sensor, and if so, executes charging the battery, otherwise, ends.

Step 2: The CPU unit performs temperature compensation on the battery according to the ambient temperature of the battery collected by the temperature sensor.

Because the storage battery has a negative temperature effect, the CPU unit needs to collect the ambient temperature of the storage battery through a temperature sensor to perform temperature compensation on the storage battery, so as to prolong the service life of the storage battery. The temperature compensated voltage is expressed as:

Ue＝U+(t-25)f (1)

In the formula, U is the actual measured voltage, t is the ambient temperature measured by the temperature sensor, f is the temperature compensation coefficient, and Ue is the voltage value after compensation.

Step 3: Real-time detection of battery voltage and temperature compensation during the charging process, high duty cycle charging is used from the 11.2V over-undervoltage point to the 13.6V floating charge point, and low duty cycle is used between the floating charge point 13.6V～14.4V Float charge; between 14.4V-14.8V, ultra-low duty cycle float charge is used, and the charge will be terminated when it reaches 14.8V.

LED street lamp drive control methods currently generally adopt three driving modes: constant voltage (CV) drive, constant current (CC) drive, and constant current and constant voltage (CCCV) drive. For the battery-powered street lamp system, the longest lighting time cannot be guaranteed, which may cause light decay. Therefore, this LED street lamp drive control method adopts a control strategy of constant current in stages, over-voltage and power-off. As shown in Figure 4, the LED street lamp drive control method includes the following steps:

Step 1: The CPU unit judges whether it is night according to the illuminance of the illuminance sensor, and if so, executes driving of the LED street lamp, otherwise, ends.

Step 2: Perform temperature compensation on the battery voltage.

Step 3: When the battery voltage is higher than 13.6V, drive the LED street lamp with a current lower than 25% of the rated current; when the battery voltage is between 12.5V and 13.6V, drive the LED street lamp with a current lower than 20% of the rated current; When the battery voltage is between 12V and 12.5V, drive the LED street lamp with a current 15% lower than the rated current; when the battery voltage is lower than 12V, stop driving the LED street lamp.

It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive, so the present invention includes and is not limited to the embodiments described in the specific implementation, and those skilled in the art according to the technology of the present invention Other implementations derived from the scheme also belong to the protection scope of the present invention.

Claims (6)

1. the solar LED street lamp control system based on photovoltaic generation, it is characterized in that: comprise LED controller for road lamp, solar panel, the first switching tube, second switch pipe, storage battery and LED street lamp, LED controller for road lamp gathers illumination information by illuminance sensor, LED controller for road lamp is connected with solar panel for gathering the voltage of solar panel, LED controller for road lamp is by the first switching tube, second switch pipe is connected with storage battery for controlling discharging and recharging of storage battery, LED controller for road lamp is connected with storage battery and realizes battery tension and temperature acquisition with temperature sensor by voltage acquisition module, the input of this storage battery is connected with solar panel by the first switching tube, the output of this storage battery is connected for its power supply with LED street lamp by second switch pipe.

2. a kind of solar LED street lamp control system based on photovoltaic generation according to claim 1, it is characterized in that: described LED controller for road lamp comprises CPU element, power supply and reseting module, voltage acquisition module, temperature collect module, fast module is controlled in illuminance sensor and output, CPU element respectively with power supply and reseting module, voltage acquisition module, temperature collect module, illuminance sensor, output is controlled fast module and is connected, this output control module control is connected with storage battery and LED street lamp and realizes the function to charge in batteries and driving LED street lamp.

3. a kind of solar LED street lamp control system based on photovoltaic generation according to claim 1, is characterized in that: described solar panel adopts polysilicon solar cell plate CETC48.150; Described storage battery adopts lead acid accumulator LCX12120ST; Described the first switching tube, second switch pipe adopt IRF530N; Described temperature sensor adopts programmable temperature sensor DS18B20; Described illuminance sensor adopts TSL256x.

4. a kind of solar LED street lamp control system based on photovoltaic generation according to claim 2, it is characterized in that: described CPU element adopts ATxmega256A3BU chip, and this CPU element is connected with temperature collect module, illuminance sensor by I2C bus connecting mode.

5. a control method for LED street lamp control system as described in claim 1 to 4 any one, is characterized in that, comprises that accumulator charging control method and LED street lamp drive control method, wherein:

Accumulator charging control method comprises the following steps:

Step 1:CPU unit judges whether it is daytime according to the illuminance of illuminance sensor, is to carry out charge in batteries, otherwise just finishes;

The ambient temperature that step 2:CPU unit gathers storage battery according to temperature sensor is carried out temperature-compensating to storage battery;

Step 3: detect in real time the battery tension trip temperature compensation of going forward side by side in charging process, put to 13.6V floating charge point and adopt high duty ratio to charge at 11.2V overvoltage/undervoltage, adopt low duty ratio floating charge between floating charge point 13.6V～14.4V; Between 14.4V～14.8V, adopt ultralow duty ratio floating charge, reach 14.8V and stop charging;

LED street lamp drives control method to comprise the following steps:

Step 1:CPU unit judges whether it is night according to the illuminance of illuminance sensor, is the driving of carrying out LED street lamp, otherwise just finishes;

The ambient temperature that step 2:CPU unit gathers storage battery according to temperature sensor is carried out temperature-compensating to storage battery;

Step 3: during higher than 13.6V, use the current drives LED street lamp lower than rated current 25% at battery tension; In the time that battery tension is between 12.5V～13.6V, use lower than rated current 20% current drives LED street lamp; Battery tension between 12V～12.5V time, is used lower than rated current 15% current drives LED street lamp; Battery tension during lower than 12V, stops driving LED street lamp.

6. a kind of solar LED street lamp control system based on photovoltaic generation according to claim 5, is characterized in that: described step 2 storage battery is carried out obtaining voltage after temperature-compensating be:

Ue＝U+(t-25)f

U is the voltage that actual measurement is arrived, and t is the ambient temperature that temperature sensor measures, and f is temperature compensation coefficient, and Ue is the magnitude of voltage after compensation.