Abstract: The union practice elaborated the scenery supplementary energy rationality, has given based on the Mcu scenery supplementary independent power supply’s hardware constitution as well as the software flow. And to key technologies: If the double sign three stage charge’s flow, contravariant module’s MCU realizes the hardware constitution and so on detailed Canadian elaboration. Simultaneously also unifies the example, introduced the scenery supplementary independent power supply system’s practical application.
Key word: Micro control clamour (MCU); Double sign three stage charges; Inversion; Scenery supplementary system
Chinese Library classification number: TM925 document code: A article serial number: 0219-2713(2005)06 0035-04
0 introductions
The comprehensive utilization wind energy, the energy of light scenery supplementary independent power supply system was one kind of reasonable electrical power system. Not can only for the electrical network power supply inconvenient area, like the border defense gate house, the communication relay station, the transportation signal station, the exploration inspection workstation as well as the farmland and pasture provides the low cost, the redundant reliable power source, moreover also opened a new path for the solution current energy crisis and the environmental pollution.
The independent solar energy or the wind energy system, as a result of the time and the region restraint, very difficult all-weather to use the solar energy and the wind energy resources. But the solar energy and the wind energy have the very strong complementarity in the time and the region, the daylight strong timely breeze is small, at night the illumination when is weak, the wind energy strengthens greatly as a result of the surface temperature difference change, the solar energy and the wind energy in the time complementarity are the scenery supplementary generating system’s in resources use optimum matchings.
l hardware constitution
The scenery supplementary independent power supply system bends down electricity generation unit by the light, the wind power generation unit, system intelligence constitutions and so on management core, invertor, stored energy part, like chart l shows.
System’s concrete constitution parameter by use when uses electricity most greatly the load and the daily average electricity consumption decision. Uses electricity the load is the selective system invertor capacity basis most greatly, but the mean diurnal power rate is chooses the air blower and the light electroplation capacity and the battery unit capacity basis. Simultaneously the system installation place the sight status of resources is also determines the electro-optical board and air blower capacity another basis.
The light bends down electricity generation unit and the wind power generation unit light bends down the electricity generation unit to use needs the scale the light to electroplate, transforms the solar energy of light, and through the intelligent management core to the battery charging, the electric discharge, the inversion carries on the global administration. The wind power generation unit use small wind-driven generator, the transformation wind energy, simultaneously permits the electric discharge through the intelligent management core control overall system. Two units supplemented mutually in energy gathering that simultaneously is also unique: The light bends down the electricity generation unit power supply to be reliable, the running attention cost is low, but the construction cost is high; The wind power generation unit power rate is high, the construction cost and the running attention cost is low, but the reliability is low.
The stored energy part lead-acid battery full scenery supplementary independent power supply system commonly used stored energy part, its cost is low, the capacity big, exempts the maintenance the characteristic to cause it to become the scenery supplementary independent power supply’s first choice. Because the wind electricity and the electro-optical unit must be able to supply power stably through the accumulator cell stored energy, the accumulator cell reasonable capacity and the science charging and discharging are the system life guarantee, this system uses the double sign three stage charges, realizes to lead-acid battery’s science charge. The scenery supplementary independent power supply uses the double stored energy system, including two set of plumbous acid battery units, enables the charging and discharging also to carry on, through the intelligent core control already may to the load electric discharge, simultaneously the fork be possible when the charge condition arrives to spare stored energy group charging, between two group of accumulator cell’s cuts by system real-time monitor its voltage condition decision.
MOSFET puts the module sufficiently by the intelligent management core actuation MOSFET charge module, may act according to system’s difference, selection different voltage class MOSFET, realizes the system to accumulator cell’s charging and discharging. MOSFET may select International Rectifier Corporation’s third generation HEXFETs product, the IR serial products has the switch to be rapid, the clear impedance is low, performance-to-price ratio higher characteristic. The control module basis different MOSFET gate level voltage design, controls the MOSFET module by the intelligent management core the output state.
The invertor system not only may provide the stable direct-current power supply, leads the DC load, moreover may through invert Lu to provide the single-phase alternating current.
The intelligent management core by the LCM liquid crystal display module, the keyboard, MCU is composed, is the systems control, the management core, actuates the MOSFET charge module to realize to accumulator cell’s double sign three stage charge, actuates JCBT to realize DC/AC to invert, as well as system’s real-time protection and the data reproduction and the transmission and so on, simultaneously provides air blower’s magnetoelectricity regulating protection, when wind power overpower, for the air blower reverse magnetic resistance moment of force, reduces the air blower rotational speed. System core MCU selects TI Corporation’s MSP430 monolithic integrated circuit, on its rich piece the resources cause system’s control and the management great convenience.
2 system principle of work and the software realize
2.1 pair of sign three stage charge principle and realizes
The lead-acid battery is system’s stored energy part, the electricity is affects the scenery supplementary system life the key aspect, to the lead-acid battery charging and discharging’s control immediate influence accumulator cell’s life, the unreasonable charging and discharging will cause accumulator cell’s collapse directly. The system intelligence management core leans on the system accumulator cell’s charging and discharging process. This system uses the double sign three stage charges to optimize the charging-up. The double sign three stage charging-up conforms to lead-acid battery’s characteristic, can maintain the accumulator cell well. Three stage charging-up as shown in Figure 2.
The first stage big electric current fills the sufficient stage (high currentbulk charge state) to gain accumulator cell’s voltage condition by the voltage sampling circuit, when the voltage has been smaller than standard open-circuit voltage (Voc), the solar energy power source, the wind-driven generator by the maximum current which its can provide to the battery charging (maximum current to different power system value are different, may according to C/5 charging rate value, C be capacity of storage battery), because solar cell and wind-driven generator’s electric current and weather conditions related, therefore big electric current value in certain scope. Maintains the big electric current charge after Voc, enters the second stage. The first stage’s charge degree may reach 70%~90%.
The second stage overvoltage permanent sufficient stage (over chargestate) by the constant standard voltage (Voc) charge, has dropped to Ioct until the charging current to enter the third stage. Second stage charge degree nearly 100%.
The third stage floating stage (float charge state) carries on the floating by constant precise floating voltage Vf. After the accumulator cell fills, by floating way sustaining voltage. Floating voltage choice to accumulator cell’s life especially important, even if 5% errors will also cause accumulator cell’s loss of life half.
Intelligent management core charge flow as shown in Figure 3. Intelligent core real-time gathering and judges the system mode, with input control, trigger pip joint control charge condition.
2.2 invertor principles with realize
The DC/DC transformation outputs by the 48V lead-acid battery through the Boost electric circuit pressure-rise to 360V, uses the UC3825PWM control chip, it produces the cow PWM frequency to be high, and the construction cost is low. DC/AC invertor main circuit by H bridge-type ICBT constitution, but also includes the fuse, the antijamming filter, the protection diode and so on. The control circuit by controls
Makes the link and the protection link two part of constitution intelligence management core as the controlling unit to main circuit’s input voltage, the output voltage, the output frequency and the output wave shape carries on the adjustment control. Protects the link to divide into the hardware protection part and the software protection part, completes to system’s short circuit, the overload, loses presses, has pressed, lacks the equal protection. After contravariant single item alternating current through voltage, electric current sensor, condition returns intelligence administrative center, in order to implement the adjustment to the profile. Invertor’s electric circuit constitution as shown in Figure 4.
2.3 systems control protection principle with realizes
The scenery supplementary electrical power system may divide into the charge condition, the state of loading according to the performance (discharge condition), the protection condition. The system simultaneously monitors the light to bend down electricity generation unit, the wind power generation unit, the load and two group of accumulator cell’s condition, under the corresponding condition, enters corresponding the condition. In each condition, the system not only completes own stage the work, but may also give the corresponding system parameters according to the user need to demonstrate that between the multi-system’s communication and the system the communication which machine asked with E, system mode flow as shown in Figure 5.
The system in the initialization, completes the parameter the hypothesis, like the light bends down the electricity generation unit voltage, the electric current, the load, the pressure, the overflow protection parameter; Wind-driven generator’s magnetoelectricity protection parameter; Lead-acid battery double sign three stage charge charge factor. Simultaneously also completes the system man-machine communication (keyboard, liquid crystal module, LED and so on) initialization and system general serial communication module hypothesis.
System condition which through the real-time sampling module, the superior machine trigger pip and the user control signal union judgment system locates. First, through the real-time sampling module gathering system’s real-time voltage, the electric current, the judgment light bends down electricity generation unit, the wind power generation unit, the stored energy accumulator cell and the load condition, thus the decision system should place condition. Next, the superior machine trigger pip and the user control signal also twist and steer control condition, may the control system change over to other conditions forcefully from one condition.
The system carries on the charge condition by the double sign two stage mise-a-la-masse methods to the lead-acid battery permits the electricity reasonably, through online the light bends down electricity generation unit to the system, the wind power generation unit, the accumulator cell and load condition gathering, completes reasonably fills sufficient and the overvoltage permanent sufficient, and by floating condition maintenance lead-acid battery’s voltage.
In the state of loading (discharge condition), according to the load need, carries on direct-current or the single item exchange power supply. Simultaneously monitors the battery unit the condition, when arrives at the hypothesis condition, realizes in turn the charging and discharging with the spare battery unit, enhances the system to the energy use. Moreover, when state of loading, lead-acid battery’s condition also needs the real-time monitor, in order to avoid has put to the accumulator cell creates the harm.
when the scenery supplementary system turban’s light bends down the protection value which electricity generation unit, the wind power generation unit, the lead-acid battery, the load as well as the system internal state variable arrive suppose, the system enters the human to protect the condition, has avoided the short circuit, the pressure, the overflow and so on to the system the harm, the safeguard system’s normal operation. If to wind-driven generator’s magnetoelectricity regulating protection, the lead-acid battery has put the protection, as well as to load overvoltage protection and so on.
At the same time, the system has provided the convenient man-machine connection, but in online gain system sufficient, electric discharge electric current, voltage parameter and system’s state variable. The general serial communication module has provided between system, system and the superior machine between correspondence, facilitates the input control, many kinds of demonstration outputs as well as the nimble correspondence have not only safeguarded system’s safe operation, also facilitates the r system’s maintenance, the overhaul and the management greatly.
3 practical applications
The scenery supplementary independent power supply system practical application has used electricity the system in the low power, like street light, home use illumination and so on. Because the solar energy, the wind energy power supply’s unique supplementary merit (as shown in Figure 6), in recent years the scenery supplementary independent power supply system obtained the rapidly expand.
If must satisfy 4 pair of 55W low pressure sodium lamp’s power supply, each light well-illuminated 7800lm, uses the l000W solar cell board on the spot according to the situation, the 300W small wind-driven generator, about two group of .400A · h lead-acid battery, may satisfy must illuminate. If must lengthen, in calm, the cloudy day continues under the condition the power supply number of days, but enlarges lead-acid battery’s capacity suitably. Here elects the concrete parameter unified the local weather conditions, the load demand condition to select.
This system union concrete street light’s practical application, meets the human to be photosensitive the component, the judgment daytime and the dark night, has realized nobody management. Like Figure 7 the flow chart shows, divides into 3 conditions the system: The condition l– accumulator cell voltage is excessively low, cannot reload, otherwise influence accumulator cell life; The condition 2– accumulator cell voltages are normal, may carry on the charging and discharging; The condition 3– accumulator cell overtensions, have the injury to the load, after must carry on the electric discharge, only then turns on the load.
4 conclusions
The scenery supplementary electrical power system has realized to the natural resource reasonable use, but the scenery supplementary technical program has guaranteed system’s redundant reliability. Not only theoretically has the guarantee based on the MCU scenery supplementary independent power supply system, moreover also obtained the examination in the practical application.
