CN201674276U - Mixed direct current power supply system for large-scale LED display screen - Google Patents

Abstract

The utility model discloses a mixed direct current power supply system for a large-scale LED display screen, comprising the followings: a multi-power supply input module (101) internally provided with solar photovoltaic, a storage battery and AC-DC; a modulation module (102) connected with the multi-power supply input module (101) to transform the input voltage into the same voltage level; an intelligent switching control module (103) connected with the modulation module (102); an expandable output module array (104) in which the number is equal to the number of LED display screen modules to output the required total current; and a GPRS remote monitoring module (105) for instantly collecting \ system parameters and transmitting the parameters to a monitoring management centre. The system implements equivalent modularization design and expansion of power supply output according to the number of the LED display screen module; and the system prompts a GPRS communication flow self-adaptation adjusting method based on monitored parameter variation gradient value, and realizes multiple power supplies intelligent switching control based on specialist system.

Description

The mixed DC power-supply system that is used for large LED display screen

Technical field

The utility model relates to a kind of DC power system, particularly a kind of mixed DC power-supply system that can be used for large LED display screen.

Background technology

LED display has been widely used in information such as land and water transportation, municipal administration, commerce, finance, residential quarter and has shown occasion, but its dc power supply has mainly still used traditional Switching Power Supply even linear power supply.Large LED display screen is to be spliced to form by a plurality of LED display modules, and the array that single led display module is made up of many single led diodes of giving out light and forming.The integral body of LED display load be along with LED display module number what and increase and decrease, present modular characteristics.On the other hand, LED display is normally worked incessantly, and accumulative total power consumption is very huge; And the conventional electric power of its installation site is laid, the monitoring of power-supply system is also very inconvenient usually with debugging.

Therefore, realizing having the multiple energy source of high reliability, can adapt to external environment condition and the input electric energy form that automaticallyes switch, can carry out the mixed DC power supply that non-maintaining remote monitoring and configuration feature were expanded and had in corresponding output according to the LED display load at large LED display screen (especially outdoor large LED display), will be the essential problem that solves of large LED display screen special DC power supply.So far, also there is not to satisfy simultaneously the mixed DC power-supply system of above-mentioned requirements.

Summary of the invention

The purpose of this utility model is to provide a kind of possess photovoltaic, storage battery, AC-DC three's intelligence switching power supply, can expand output according to the quantity of LED display module, can realize the parameter monitoring and the setting of remote live by the GPRS wireless network, be particularly useful for conventional power supply inconvenience and need the novel mixed DC power-supply system of the large LED display screen of long-term work.Described mixed DC power-supply system can realize that the automatic unperturbed of multiple electric energy switches, power supply performance is stable, alleviated the cost performance height of personnel's maintenance and management workload, total system, reached the target of high-efficient energy-saving environment friendly.

The technical scheme in the invention for solving the technical problem is: described mixed DC power-supply system has comprised the multiple Power Entry Module 101 that produces electric energy with multitude of different ways; Directly link to each other with described multiple Power Entry Module 101, direct voltage is converted into the modulation module 102 of same electric pressure; Link to each other with described modulation module 102, determine the intelligent switching controls module 103 of any power supply of switching by detecting extraneous switching condition automatically; Link to each other with described intelligent switching controls module 103, and can carry out the output module the expanded array 104 of equity configuration according to described LED display number of modules; Gather the various parameters of described power-supply system, and can regulate the GPRS communication traffic adaptively, to be sent to the GPRS remote monitoring module 105 of supervision and management center in real time.

As the utility model scheme, described multiple Power Entry Module 101 comprises the multiple power supply that produces electric energy with photovoltaic, storage battery, AC-DC different modes.Described intelligent switching controls module 103 is to be core with the microcontroller, gathers outside switching condition by testing circuit; And use the inner expert's control algolithm that realizes of described microcontroller, by electronics or mechanical switch device, realized the switching controls between the different electrical power in the system automatically.The described output module array 104 of expanding is to be formed in parallel by single submodule, and the input of described single submodule is connected with intelligent switching controls module 103 outputs, and its output directly is connected with the display module of LED display; Described single submodule is to be core with the integrated switch element, and the Buck circuit that is made of capacitor, inductor, fly-wheel diode, and its output current can satisfy the required running current of single led display module.

In the utility model scheme, described GPRS remote monitoring module 105 comprises: the sample circuit 501 of importing monitored parameter; Realize analog-to-digital A/D change-over circuit 502; Carry out local protection control, ask for the microcontroller 503 that the parameter variable gradient is also adjusted the GPRS flow adaptively; The communication data packing is sent to the GPRS network interface chip 504 of wireless communication networks; Radio-frequency (RF) power amplification unit 505 and the SIM card interface circuit 506 that signal amplifies will be sent.

When the utility model used: described intelligent switching controls module 103 was gathered external conditions, and according to the Expert Rules storehouse of its inside, to determine a certain power supply of switching to described multiple Power Entry Module 101; Described when expanding output module array 104 and being connected to the LED display module, the output current of its single submodule and single led display module equity coupling are to carry out the equity expansion of output array according to the quantity of described LED display module; The various parameters of described GPRS remote monitoring module 105 acquisition systems, carry out data communication by the wireless GPRS network with the form and the supervision and management center of IP packet, and regulate communication traffic with self adaptation based on monitored parameter variable gradient value, guaranteed the real-time of remote monitoring.

The beneficial effects of the utility model are: (1) has introduced new electric energy forms such as photovoltaic, storage battery, realized the variation of energy source, reached energy-efficient target, the long-term history of using the linear power supply of single Switching Power Supply even inefficiency of the LED display that is through with; (2) by analyzing the switching condition of AC-battery power source,, realized the intelligent unperturbed switching controls of AC-battery power source based on expert's switching controls rule; (3) expansion structure of modular parallel has been adopted in the output of described AC-battery power source, can be according to the quantity of LED display module and carry out the increase and decrease of output module easily and flexibly, thus strengthened the extensibility of system; (4) utilize GPRS module and mobile internet network technology, regulate, improved the real-time that system remote monitoring and diagnosis are safeguarded by communication traffic self adaptation based on controlled parameter variable gradient value; (5) described AC-battery power source has structurally adopted idea of modular, and each module realizes independently all and collaborative work that local fault can not be diffused into other parts, has improved the global reliability of system.

Description of drawings

Fig. 1 is the overall structure block diagram of system described in the utility model;

Fig. 2 is the cut-away view of multiple Power Entry Module and modulation module;

Fig. 3 is the cut-away view of intelligent switching controls module;

Fig. 4 is the cut-away view that can expand the output module array;

Fig. 5 is the cut-away view of GPRS remote monitoring module;

Fig. 6 is the flow chart of system work process described in the utility model

Fig. 7 is the switching controls state diagram of expert's control algolithm;

Fig. 8 is the state truth table of expert's control algolithm;

Fig. 9 is the cut-away view of LED display module;

Figure 10 is the structure chart of GPRS wireless communication networks;

Figure 11 is that the variable gradient value and the GPRS network of monitored parameter sends the period-luminosity relation schematic diagram;

Figure 12 is the variable gradient value of monitored parameter and the correspondence table that GPRS network sends the cycle.

Embodiment

The utility model is described in further detail below in conjunction with drawings and Examples.

Referring to Fig. 1, it has shown the overall structure block diagram of mixed DC power-supply system described in the utility model, and it comprises: multitude of different ways produces the multiple Power Entry Module 101 of electric energy; Its output is connected to modulation module 102 so that different direct voltages are converted into same electric pressure; Intelligence switching controls module 103 links to each other with described modulation module 102, by detecting extraneous switching condition and using expert's control algolithm to realize the automatic switchover of different electric energy; Can expand output module array 104 and link to each other with described intelligent switching controls module 103, its output is connected to the display module of LED display, and it has carried out reciprocity configuration and expansion according to LED display module number; GPRS remote monitoring module 105 is gathered the various parameters of described power-supply system, and employing is based on the self adaptation GPRS flow rate adjusting method of monitored parameter variable gradient value, to the remote monitoring and administration center, it also can receive the system configuration information that supervision and management center sends on the other hand with transmitting data in real time.

Referring to Fig. 2, it has shown the internal structure of multiple Power Entry Module 101 and modulation module 102.Described multiple Power Entry Module 101 has comprised: solar energy photovoltaic panel 201, storage battery 202, AC-DC power supply 203, and this three is connected to modulation module 102 with the parallel form DC power output; Described solar energy photovoltaic panel 201 can be connected with serial or parallel connection and compound mode thereof by a plurality of monolithic solar energy photovoltaic panels, to reach suitable electric pressure and enough electric currents are provided; Described storage battery 202 can be connected with serial or parallel connection and compound mode thereof by a plurality of independent storage batterys, to reach suitable electric pressure and enough electric currents are provided; Described AC-DC power supply 203 is powered by industrial-frequency alternating current, and is converted into suitable direct voltage and enough electric currents are provided.

In Fig. 2, modulation module 102 has been realized the collaborative modulation and the isolated variable of different voltages between input photovoltaic, storage battery, the AC-DC.In the described modulation module 102, solar energy photovoltaic panel 201 is connected with storage battery 202 by management of charging and discharging circuit 204 with AC-DC power supply 203; This management of charging and discharging circuit adopts the negative pulse depolarising, punctures crystallization sulfide, eliminates and overcharge, and has effectively guaranteed the life of storage battery.The very little direct current of smoothly being pulsed behind the Π shape filter circuit that solar energy photovoltaic panel 201 is formed by capacitor C 1, C2 and inductance L; Diode D1, D2 prevent current reversal, and switching device K1, K2 realize three kinds of isolated from power and switching, and its output is converted into identical direct voltage grade through modulation, outputs to intelligent switching controls module 103 again.

In embodiment of the present utility model, solar energy photovoltaic panel 201 has adopted polycrystalline silicon solar photovoltaic panel CETC48-150, and its crest voltage is that 16.65V, peak current are 8.88A under 25 ℃ of situations of 1000 illumination; Storage battery 202 has adopted lead acid accumulator LC-X12120ST, and this battery capacity is 120AH; AC-DC 203 adopts Universal, modular AC-DC power supply, and its output voltage grade is+12V that electric current is 25A.Because above-mentioned three's output voltage grade is approximate, simplifies for modulation module 102 among the embodiment; Management of charging and discharging circuit 204, diode D1, D2, Π shape filter circuit and switch element K1, K2 together constitute modulation module 102.Management of charging and discharging circuit 204 has comprised starting of oscillation, logic, switch, four parts of rectification.The starting of oscillation part is made of the RC oscillating circuit, and the concussion pulse produces level signal through logical gate and is sent to Schmidt trigger CD4042, forms the conducting of the opposite pwm signal of two-way phase place with the control triode.Switch sections adopts two groups and the N raceway groove that connects and P-channel field-effect transistor (PEFT) to pipe K2956 and J471.Rectifying part adopts bridge rectifier.Starting of oscillation and logical gate adopt the CD4069UBE integrated chip, and it has the symmetrical output characteristic of standard.

Referring to Fig. 3, it has shown the cut-away view of intelligent switching controls module 103.Described intelligent switching controls module 103 comprises: gathered voltage in the multiple Power Entry Module 101 by sensor groups 301, electric current, analog signals such as temperature, after process modulate circuit 302 carries out filtering and voltage transformation, send into A/D (A-D converter) 303 and convert digital signal corresponding to, and then send into microcontroller 304, expert's control algolithm realized in the described microcontroller 304 inner C language that adopt, the control command that this algorithm process of process obtains is after the amplifying circuit 305 of overdriving carries out power amplification, further driving switch device 306 work, simultaneously microcontroller 304 also sends to status command state indication 307, indicates the current switching state of intelligent switching controls module 103.The switching controls principle of described intelligent switching controls module 103 is: preferential switching photovoltaic electric energy, simultaneously with unnecessary electrical power storage in storage battery; At night or overcast and rainy once in a while when causing the solar cell electric energy not enough, switching uses the storage battery electric energy; Only continuous when overcast and rainy, solar energy and storage battery all can't operating position under, just switch to AC-DC power supply by the civil power energy supply.

In embodiment of the present utility model, voltage sensor 301 adopts resistor voltage divider network; Current sensor 301 adopts constantan wire and integrated transporting discharging LM358N; Temperature sensor 301 adopts DS18B20, and it has the single bus interface mode, temperature measurement range-55 ℃～+ 125 ℃, and certainty of measurement is 0.5 ℃, and the automatic alarming value of temperature over-range can be set; A/D (analog/digital converter) 303 adopts the analog comparator Comparator_A and the timer Time_A of microcontroller inside, and institute constitutes slope (Slope) A/D and changes; Microcontroller 304 has adopted 16 low-power scm MSP430, operating voltage 1.8～3.6V, and the operate as normal power consumption can be controlled in below the 200 μ A; Drive amplifying circuit 305 and adopt S8050 triode amplified current; Switching device 306 adopts operating voltage to be+5V the solid-state relay of maximum current 10A; State indicating module 307 has adopted the LED light-emitting diode.

Referring to Fig. 4, it has shown the cut-away view that can expand output module array 104.The described output module array 104 of expanding comprises: through in parallel and constituted output array, concrete output sub-module number in parallel can be according to the number (being the load scale) of LED display module 402 and adaptive configuration by a plurality of output sub-module expanded 401; Described output sub-module 401 inside of expanding are again to be made of DC-DC translation circuit 4011 and Voltage Feedback PWM regulating circuit 4012, input voltage instability when DC-DC translation circuit 4011, when causing its output voltage fluctuation, Voltage Feedback PWM regulating circuit 4012 utilizes the output voltage of DC-DC translation circuit 4011 as feedback signal, adjust the duty ratio of PWM modulating wave in the DC-DC conversion, thereby make its output voltage all-the-time stable in nominal value.The input that can expand output sub-module 401 is connected with intelligent switching controls module 103, and its output is connected to pairing LED display module, and powers to it with the nominal voltage value.

In embodiment of the present utility model, can expand output sub-module 401 and be with integrated switch element LM2576 is core, is aided with electric capacity, inductance, fly-wheel diode and constitutes the BUCK circuit.LM2576 is the integrated voltage stabilizing chip of the step-down switching type of output current 3A; inside contains fixed oscillator (52KHz) and benchmark pressurizer (1.23V); and have threshold currents, protective circuits such as heat shutoff etc., utilize this device can constitute more easily+the efficient voltage stabilizing output sub-module of 5V.

Referring to Fig. 5, it has shown the cut-away view of GPRS remote monitoring module 105.Described GPRS remote monitoring module 105 comprises: gather analog signal parameter such as voltage, electric current, temperature, humidity in this hybrid power source system by sample circuit 501, convert digital signal to through A/D (analog/digital converter) 502 and reach microcontroller 503 afterwards; Adopt the C language compilation transmission cycle data to be set in the described microcontroller 503, and then be connected with GPRS network interface chip 504 through standard serial port based on the adaptive communications Flow-rate adjustment algorithm of variable gradient value; Described GPRS network interface chip 504 has been opened the SIM card number of GPRS service function by SIM card circuit 506 with identification, and further by radio-frequency (RF) power amplification unit 505 the IP packet is sent to GPRS network, finishes the exchanges data with wireless Internet network; By the computer receiving data of remote monitoring center, finish real-time monitoring and diagnosis maintenance at last.

In embodiment of the present utility model, sample circuit 501 is with 301; A/D (analog/digital converter) 502 is with 303; Microcontroller 503 is with 304; 504 of GPRS network interface chips have used integrated GPRS wireless communication module MC55.It is low-power consumption (peak current 450mA) three wireless modules frequently, except the original function with gsm module, also supports the Packet Service function, and built-in ICP/IP protocol, AT command set.The metadata cache that MC55 also has 5K is used for the GPRS data packet transmission, can satisfy the needs that total data is gathered in the native system.Radio-frequency (RF) power amplification unit 505, SIM card circuit 506 have all adopted the standarized component of standard radio communication terminal to realize, have guaranteed the compatibility of the network equipment.

Referring to Fig. 6, it has shown the flow chart of system work process described in the utility model.The workflow of described system comprises: S101. switches based on the intelligence that expert's control algolithm is carried out multiple power supply; S102. realize the peer modules design and the expansion of output module array; S103. realize regulating based on the GPRS communication traffic self adaptation of monitored parameter variable gradient value.

The intelligence of carrying out multiple power supply based on expert's control algolithm is switched S101, specifically comprises: at first determine the pairing outside switching condition of input power supply; Next is data and switching principle rule of thumb, sets up the Expert Rules storehouse, and no matter which kind of state is system be in all has corresponding switching law to carry out in this storehouse; Utilize specific programming language to make up the switching controls function by gathering outside switching condition then; Call the switching controls function at last to carry out under this state Expert Rules corresponding in the experts database, with the carrying out of guaranteeing to automatically switch.The main body of described expert's control algolithm is one and solves the instruction regular collection that native system automaticallyes switch and controls, by detecting extraneous switching condition and make logic determines with the specific input power supply of switching, the input power supply of chosen switching can be a kind of among photovoltaic, storage battery, the AC-DC.

Referring to Fig. 7, it has shown the switching controls state diagram of described expert's control algolithm: the outside switching condition that sampling is obtained is sent to microprocessor through filtering, conversion formation voltage signal; When solar panels voltage is judged as high level during greater than preset value (12V), otherwise be judged as low level; The switching control procedure also will be considered the photovoltaic panel trouble free service, must discharge and recharge the in addition strict restriction of condition to it; For preventing overcharge of a battery, Acquisition Circuit is passed to microprocessor with the magnitude of voltage and the current value of storage battery in real time, when battery tension greater than default when going up dividing value (14.4V) and current value and being lower than default floor value (30mA), judge that storage battery is full of, then disconnecting storage battery influences battery useful life in order to avoid overcharge, and provides required electric power separately by solar energy; In order to prevent the storage battery deep discharge, supervisory circuit is passed to microprocessor in real time with the battery tension value and the current value that collect equally, when being lower than default floor value (9V), the magnitude of voltage of storage battery is judged as low level, microprocessor output this moment control signal is passed through switch element K1, K2 to connect civil power, civil power becomes direct current through step-down rectifier and charges a battery, and provides electric power to load simultaneously.

Referring to Fig. 8, it has shown under the situation of the outside switching condition input of difference, the output state truth table of described expert's control algolithm: for switching device K1 (open type), and " 1 " expression switch motion closure, " 0 " expression switch is failure to actuate and is opened; For switching device K2 (closed type), " 1 " expression switch motion is opened, " 0 " expression switch closure of being failure to actuate.

In embodiment of the present utility model, it is as follows to utilize class C language to realize that described intelligence is switched expert's control procedure:

1. choose and determine outside switching condition:

The outside initial conditions that switches: solar energy photovoltaic panel voltage (V _S), charge in batteries electric current (I _B), battery tension (V _B); Output controlled quentity controlled variable: switching value K1, switching value K2.

2. set up the rule base of expert's control algolithm

Switching controls rule base ()

{

A.K1 disconnects ﹠amp; ﹠amp; K2 closure // this operation is suitable under the situation of solar energy or storage battery abundance, by the sun

Can power supply or by storage battery power supply (solar powered holding || powered battery);

Perhaps all power supplys are all unavailable, and system is in complete power failure state, this

The time storage battery cut off protection automatically, system etc. by K1, K2

Wait to power on and restart

The closed ﹠amp of B.K1; ﹠amp; K2 disconnection // this operation is suitable for the situation that solar energy does not have electricity and storage battery impulse electricity overcurrent

Down, (solar energy does not have have ﹠amp by mains-supplied; ﹠amp; Storage battery impulse electricity overcurrent)

C.K1 disconnects ﹠amp; ﹠amp; K2 disconnection // this operation is suitable under all sufficient situation of solar energy and storage battery, by too

Sun can directly be powered, and (solar energy is directly ﹠amp directly; ﹠amp; Storage battery is full of);

Perhaps under the situation of solar energy abundance and storage battery impulse electricity overcurrent, by too

Sun can directly be powered, and (solar energy is directly ﹠amp directly; ﹠amp; Storage battery impulse electricity mistake

Stream)

The closed ﹠amp of D.K1; ﹠amp; K2 closure // this operation is suitable for solar energy and storage battery does not all have under the situation of electricity, by the city

(solar energy does not have have ﹠amp in the electricity power supply; ﹠amp; Civil power charges a battery)

}

3. make up the switching controls function:

Void Expert_Switch_function(float?V _S，float?V _B，float?I _B)

//V _SBe solar energy photovoltaic panel voltage, V _BBe battery tension, I _BBe the charge in batteries electric current

{

If(V _S＜12V?&&?V _B＜9V?&&?I _B＜500mA)

{K1＝1；K2＝0；}；

If(V _S＜12V?&&?V _B＜9V?&&?I _B＞500mA)

{K1＝1；K2＝1；}；

If(V _S＜12V?&&?V _B＞9V?&&?I _B＜500mA)

{K1＝0；K2＝0；}；

If(V _S＜12V?&&?V _B＞9V?&&?I _B＞500mA)

{K1＝1；K2＝1；}；

If(V _S＞12V?&&?V _B＜9V?&&?I _B＜500mA)

{K1＝0；K2＝0；}；

If(V _S＞12V?&&?V _B＜9V?&&?I _B＞500mA)

{K1＝0；K2＝1；}；

If(V _S＞12V?&&?V _B＞9V?&&?I _B＜500mA)

{K1＝0；K2＝1；}；

If(V _S＞12V?&&?V _B＞9V?&&?I _B＞500mA)

{K1＝0；K2＝1；}；

}

4. utilize and regularly interrupt calling the switching controls function:

Timer0 and registers group 1 are regularly interrupted in Void T0_Int () interrupt1 using 1 // use

{ external long sreg; // quote outside timing time number variable

TR0=0; // stop timer Timer0

TH0=0xFF; TL0=0xEF; // heavily loaded timer Timer0=1ms

TR0=1; // restart timer Timer0

Sreg=sreg+1; // regularly time number variable adds 1

If (sreg==600000) // timing was just carried out handover operation next time after 10 minutes

{ sreg=0; // zero clearing is time number variable regularly

Get_AD (﹠amp; V _S， ﹠amp; V _B， ﹠amp; I _B); // call the AD function, obtain current V _S, V _B, I _BInput value

Expert_Switch_function (V _S, V _B, I _B); } // call switching controls function

}

The peer modules design of described realization output module array and expansion S102 specifically comprise: the payload that at first calculates single led display module; Next calculates the unit area loading size of LED display; According to the respective modules design principle, obtain the required power supply output sub-module number of LED display unit are then; According to equity expansion principle, determine to expand the overall submodule number of output module array, at last to provide LED display work required gross power.

In embodiment of the present utility model, can expand the output module array is to be made of single submodule parallel connection, and the output current of described single submodule is corresponding to the load current of single led display module; Therefore the corresponding expansion output module array neutron number of modules according to LED display module number just can be provided by the total current that provides the LED display operate as normal required.Its implementation procedure is as follows:

1. calculate the load of single led display module

Referring to Fig. 9, it has shown the cut-away view of LED display module.The LED display module is to be made of the form of a plurality of LED diodes according to the ranks grid, once refreshes the single file data of serial, to control flickering of the corresponding LED of delegation diode.

LED number in the full load of single led display module (bright entirely) electric current=total pixel of LED display module * every pixel

Current value/the number of scans of * single led pipe

In the following formula, the current value of single led pipe is generally 5～20mA, normally is taken as 10mA; The general indoor screen of number of scans is 16 to sweep, and the semi-outdoor screen is 8 to sweep or 16 sweep, and outdoor screen generally is 4 to sweep, 2 sweep or static (1 sweeps).

In embodiment of the present utility model, for the single led display module of the indoor screen of standard 5.0 dual base colors at full capacity electric current be:

The full load electric current of single led display module=(32 * 64) * 2 * 0.01/16=2.56A

2. calculate the unit area loading of LED display

In embodiment of the present utility model, for the unit are of the indoor screen of standard 5.0 dual base colors at full capacity (bright entirely) electric current be:

2.56A * 5V/ (0.488m length * 0.244m height)=107W/m ²

3. obtain the required power supply output sub-module number of LED display unit are

According to embodiment of the present utility model, can expand the output module array is to be made of single submodule parallel connection; Each submodule all is to be the Buck circuit of core with the integrated switch element, and output voltage is+5V that maximum output current is 3A.It satisfies the respective modules designing requirement of the indoor screen LED of standard 5.0 dual base colors display module.Therefore, should be at the required power supply output sub-module number of above-mentioned LED display unit are:

107W/ (7 of the ≈ of 3A * 5V)

4. determine to expand the submodule total number of output module array

According to embodiment of the present utility model, expand principle for the indoor screen of standard 5.0 dual base colors according to equity, the respective extension according to LED display area size, the submodule total number of obtaining in the power supply output module array should be:

Piece (S/1) * 7=7 * S piece

As LED display area S=9m ²The time, the submodule total number that then can expand the output module array is 7 * 9=63 piece.

According to another embodiment, sweep (2 red 1 green 1 indigo plant) 8 * 16 dot matrix full-color screens at open air 4, the full load electric current of its LED display module is: (8 * 16) * 4 * 0.01/4=1.28A; Its unit area loading is: 1.28A * 5V/ (0.256m length * 0.128m height)=195W/m ²So the required power supply output sub-module number of this LED screen unit are is: 195W/ (13 of the ≈ of 3A * 5V); The area of this LED display is 12m again ², the then required output sub-module expanded total number should be: 12m ²/ 1m ²* 13=156.

Described realization is regulated S103 based on the GPRS communication traffic self adaptation of monitored parameter variable gradient value, specifically comprises: at first, need to make up GPRS communication network and PPP (Point-to-Point Protocol) link; Secondly, heartbeat packet should be set connects to keep network; At last, should calculate the Grad of monitored parameter, and change the transmission cycle of heartbeat packet according to its size.

In embodiment of the present utility model, described GPRS communication traffic self adaptation adjustment process based on monitored parameter variable gradient value is as follows:

1. make up GPRS communication network and ppp link

Referring to Figure 10, it has shown the structure chart of GPRS wireless communication networks.Described GPRS wireless communication networks system comprises: mixed DC power-supply system, GPRS remote monitoring module, GPRS network, Internet network and five parts of supervision and management center.Each mixed DC power-supply system all is connected to GPRS network by described GPRS remote monitoring module, and the network topology form can be star or free topology; The GPRS remote monitoring module is to insert GPRS network in APN (Access Point Name) mode, it has realized the collection and the filtering of system parameterss such as voltage, electric current, temperature, humidity in the described mixed DC power-supply system, and described various parameter sends to adjacent base station (Basic Station System) by the wireless GPRS network with block form after being converted to the IP packet through packing; The IP packet finally is transferred to the Internet network through the background server of mobile operator, and the server of supervision and management center receives the IP packet and extracts monitored parameter by the Internet network, thereby has realized long-range real-time monitoring.

Before utilizing the GPRS Packet Service to carry out communication, must hold consultation and set up PPP (Point-to-PointProtocol) link with GPRS network.Typical ppp link is set up process and is divided into three phases: the phase I is the link establishment stage, has used LCP LCP (Link Control Protocol); Second stage is an authentication phase, uses password authentication protocol PAP (Password Authentication Protocol) or challenge handshake authentication protocol CHAP (Challenge handshakeauthentication protocol); Phase III is the network negotiate stage, has used IP control protocol IPCP (Internet ProtocolControl Protocol).Through behind the above-mentioned three phases, can set up a complete ppp link.

2. heartbeat packet is set to be connected to keep network

GPRS network connected and packet data protocol activation after, if surpass the timing of network settings, the GPRS Mobility Management state can enter into the Idle state from the Ready state, and packet data protocol also jumps to deactivation status from state of activation, connects thereby make the GPRS transmission terminal disconnect.At this moment, network system is with the transmission route information deletion, thereby can cause network to go offline and the data packet loss.

In embodiment of the present utility model, solve the GPRS network disconnection and adopted the heartbeat packet triggering technique.Heartbeat packet triggers and is meant in the setting-up time interval, periodically initiatively send out link maintenance information, trigger gateway access point (GGSN), Service Access point (SGSN), the inner waiting timer of travelling carriage (MS), make transmission link return back to initial condition, thereby keep the connection of data transmission link.

In embodiment of the present utility model: after the GPRS remote monitoring module has activated the network connection, will start the triggering process of a heartbeat packet; Adopt timer that the transmission time interval of heartbeat packet is set in this process, the default cycles value is 60 seconds; When timer regularly arrives, the GPRS remote monitoring module will send heartbeat packet to supervision and management center, to realize refreshing mobility management states timers such as Home Location Register, GGSN and SGSN; Various monitored parameters also are filled in the heartbeat packet packaged in the described mixed DC power-supply system, send to long-range supervision and management center in real time.

3. calculate the Grad of monitored parameter, and change the transmission cycle of heartbeat packet according to its size.

The heartbeat packet transmission being set during the cycle, can not regularly be provided with too shortly, the transmission cycle, too short meeting caused the increase of communication fee; But heartbeat packet sends excessive cycle, can cause network to go offline again or influences the real-time of monitored data.The size of Grad has been represented the variation speed of monitored parameter, can be as real-time weak index.Therefore, system described in the utility model has taked the monitored parameter variable gradient value of foundation and has dynamically adjusted the communication dispatch strategy that heartbeat packet sends the cycle.

The concrete steps that the heartbeat packet transmission cycle is set are: at first, the Grads threshold of setting separately at the monitored parameter of various differences divides into groups (corresponding to the transmission cycles of different sizes); Secondly according to gradient formula, calculate the Grad of each monitored parameter in real time; At last, the Grad of monitored parameter is compared with corresponding Grads threshold grouping, thereby determine transmission cycle of this parameter.For univariate real function, gradient is exactly its derivative; Thereby in embodiment of the present utility model, adopted the single step differentiate formula that disperses:

Grad＝[Y(k)-Y(k-1)]/T

In the following formula, Y (k) is the currency of monitored parameter, and Y (k-1) is last value, and Grad is the variable gradient value, and T is its transmission cycle.

Referring to Figure 11, it has shown the variable gradient value of monitored parameter and the relation that GPRS network sends the cycle.Abscissa is represented the Grad of certain monitored parameter among this figure, and ordinate represents that the network under the corresponding Grad sends the cycle.As seen from the figure, along with the Grad increase of monitored parameter, its network transmission cycle (also being that heartbeat packet sends the cycle) presents stepped successively decreasing; And the Grad correspondence in the certain limit unique network and is sent the cycle.Referring to Figure 12, it has shown the conversion Grad of monitored parameter among the utility model embodiment and the mapping table that GPRS network sends the cycle.Monitored parameter in the table has comprised voltage, electric current, temperature, humidity of system etc.

In embodiment of the present utility model, adopt class C language to realize that the self adaptation adjustment process of communication traffic is as follows:

Grad_function (float X1, float X2) //X1 is previous monitored parameter value, X ₂Be its currency

{ float?gradY；

GradY=fabs ((X2-X1)/T); // obtaining the absolute value of gradient according to formula, T is the heartbeat packet timer value

Return (gradY); } // return gradient absolute value

Timer0 and registers group 2 are regularly interrupted in Void T0_Int () interrupt 1 using 2 // use

{ byte i, j, flag; // temporary variable is set and sends indexed variable

float?G[4][7]＝{{0.1，0.2，0.5，1.0，1.5，2.0，4.0}，{0.1，0.2，0.3，0.5，0.8，1.0，1.5}，

0.1,0.2,0.5,1.0,1.5,2.0,2.5}, 0.2,0.4,0.6,0.8,1.0,2.0,3.0}}; // Grads threshold of parameters is set

Float g[4]; // deposit each the parameter gradients value that calculates

External float X_K[4], X_K1[4]; // quote global variable, deposit the currency and the last sub-value of each parameter

Word T[8]=60000,50000,40000,30000,20000,10000,5000,5000}; // depositing Grads threshold divides into groups

External word t[4]; // quote global variable, to deposit the transmission periodic quantity of each parameter

TR0=0; // stop timer Timer0

TH0=0xFF; TL0=0xEF; // heavily loaded timer Timer0=1ms

TR0=1; // restart timer Timer0

Flag=0; // clear to send indexed variable

for(i＝0；i＜4；i++)

T[i]--; The transmission periodic variable of // each parameter subtracts 1

The transmission cycle of if (t[i]==0) // be designated as down i parameter regularly arrives

{ flag=1; // the transmission indexed variable is set

get_AD(&X_K[0]，&X_K[1]，&X_K[2]，&X_K[3])；

// call the AD function, obtain the currency of each parameter

g[i]＝Grad_function(X_K1[i]，X_K[i])；

// call gradient function, calculate the current Grad of each parameter

T[i]=T[0]; // the transmission cycle is set is default value

for(j＝0；j＜7；j++)

if(g[i]＞G[i][j]){t[i]＝T[j+1]；break；}

// by this variable Grad, ask for the corresponding transmission cycle

}

}

If (flag==1) Send_Data (X_K[0], X_K[1], X_K[2] and, X_K[3]); Current each the parameter value X_K of // transmission

for(i＝0；i＜4；i++)X_K1[i]＝X_K[i]；}

// the currency X_K of each parameter is saved among the X_K1

}

In the utility model, guaranteed the transmission real-time of monitored parameter according to above-mentioned adjustment process, and greatly reduced the GPRS remote monitoring module information flow-rate, saved communication fee.

Claims (6)

1. a mixed DC power-supply system that is used for large LED display screen is characterized in that, comprising:

Produce the multiple Power Entry Module (101) of electric energy with multitude of different ways;

Directly link to each other with described multiple Power Entry Module (101), direct voltage is converted into the modulation module (102) of same electric pressure;

Link to each other with described modulation module (102), by detecting extraneous switching condition and using expert's control algolithm to determine any power supply of switching, with the intelligent switching controls module (103) that realizes automaticallying switch;

Link to each other with described intelligent switching controls module (103), and carry out the output module the expanded array (104) of equity configuration according to described LED display number of modules;

Gather the various parameters of described power-supply system, and come self adaptation to regulate communication traffic, to be sent to the GPRS remote monitoring module (105) of supervision and management center in real time based on the variable gradient value of described parameter.

2. mixed DC power-supply system according to claim 1 is characterized in that, described multiple Power Entry Module (101) comprises solar energy photovoltaic panel, storage battery and AC-DC power supply.

3. mixed DC power-supply system according to claim 1 is characterized in that, described intelligent switching controls module (103) is to be core with the microcontroller, gathers outside switching condition by testing circuit; And use the inner expert's control algolithm that realizes of described microcontroller, by electronics or mechanical switch device, realize the switching controls between the different electrical power in the main circuit automatically.

4. mixed DC power-supply system according to claim 1, it is characterized in that, the described output module array (104) of expanding is to be formed in parallel by single submodule, the input of described submodule is connected with intelligent switching controls module (103) output, and the output of described submodule directly is connected with the display module of LED display; And the described submodule quantity of expanding output module array (104) has been carried out reciprocity configuration and expansion according to the quantity of described LED display module.

5. mixed DC power-supply system according to claim 4 is characterized in that, described single submodule is to be core with the integrated switch element, and the Buck circuit that is made of capacitor, inductor, fly-wheel diode; Input voltage is 7V～40V, and output voltage is 5V, and single submodule maximum output current is 3A, and average operating efficiency can reach 70%～90%.

6. mixed DC power-supply system according to claim 1 is characterized in that, described GPRS remote monitoring module (105) comprising: the sample circuit (501) of importing monitored parameter; Realize modulus A/D change-over circuit (502); Carry out local protection control, calculating parameter variable gradient and self adaptation and adjust the microcontroller (503) of GPRS flow; The communication data packing is sent to the GPRS network interface chip (504) of wireless communication networks; Radio-frequency (RF) power amplification unit (505) and the SIM card interface circuit (506) that signal amplifies will be sent.

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