CN102979656A

CN102979656A - Self-adaptive high energy ignition system

Info

Publication number: CN102979656A
Application number: CN2012105249168A
Authority: CN
Inventors: 朱一骁; 单熠君; 翁博文; 曾庆喜
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2012-12-10
Filing date: 2012-12-10
Publication date: 2013-03-20

Abstract

The invention relates to a self-adaptive high energy ignition system, belonging to the technical field of an engine ignition system. The system comprises a storage battery, a 400W small power boosted circuit, an energy buffer, an energy buffer protection circuit, a buffer energy measurement circuit and a system control CPU (Central Processing Unit), wherein the storage battery, the 400W small power boosted circuit and the energy buffer are connected in order; the energy buffer protection circuit, the energy buffer and the buffer energy measurement circuit are connected in order; and the buffer energy measurement circuit, the system control CPU and the 400W small power boost circuit are connected in order. The self-adaptive high energy ignition system is strong in reliability, high in stability, good in anti-interference capability and good in heat dissipation.

Description

A kind of self adaption high-energy ignition system

Technical field

The present invention relates to a kind of self adaption high-energy ignition system, belong to the engine igniting system technical field.

Background technique

Under the current energy and the increasingly international overall background of environmental issue, the high energy consumption of traditional combustion engine, poor efficiency, multicontaminated defective highlight day by day, how to improve combustion efficiency and power performance and become the focus that engine research, development is paid close attention to.Than traditional engine ignition mode, high-energy ignition has higher advantage and vast potential for future development more.High-energy ignition improves rate of burning and sophistication by improving ignition energy, thereby reaches the comprehensive purpose of improving engine performance, and it is for the adaptive capacity of changeable operating mode and all considerable to the contribution that improves delivery efficiency.In the energy-intensive world today, realize that the extensive use of high-energy ignition becomes a kind of trend; Simultaneously, motor needs cylinder body is carried out preheating, the rotation of band mechanical starter, starts high-energy ignition system in the process of cold start-up.The power supply of these equipment all comes from same group storage battery, needs storage battery that larger power stage is provided at short notice, and the volume and weight that this must increase storage battery is unfavorable for the weight saving of motor.

Summary of the invention

The present invention proposes a kind of self adaption high-energy ignition system, in the situation that does not increase volume and weight, realize motor power supply boost short time, high voltage, the high-power output intent of 400W small-power booster circuit part.

The present invention adopts following technological scheme for solving its technical problem:

A kind of self adaption high-energy ignition system; comprise storage battery, 400W small-power booster circuit, energy buffer, energy buffer protective circuit, buffer energy measurement circuit and the control CPU of system; wherein; storage battery, 400W small-power booster circuit and energy buffer are linked in sequence; energy buffer protective circuit, energy buffer and buffer energy measurement circuit are linked in sequence, and buffer energy measurement circuit, the control CPU of system and 400W small-power booster circuit are linked in sequence.

Beneficial effect of the present invention is as follows:

1, in super overload part, uses " energy buffer " of capacitance energy storage type.By the energy storage of capacitor, so that in output, other firing mode under the identical condition of power supply of output energy Ratios are significantly improved, realized the requirement of overload.

2, under low voltage, native system has been realized repeatedly high-energy ignition, is capacitor discharge type compared to traditional C DI() lighting a fire has remarkable superiority; Simultaneously, repeatedly counting of high-energy ignition has remarkable superiority compared to traditional inductance igniting.

3, the native system reliability is strong, stability is high, and antijamming capability is good, and heat radiation is good.

Description of drawings

The general structure block diagram of Fig. 1 system.

Fig. 2 400W small-power booster circuit schematic diagram.

Fig. 3 Boost converter circuit figure.

Fig. 4 (a) Boost transducer charging process circuit diagram; Fig. 4 (b) Boost transducer discharge process circuit diagram.

Fig. 5 (a) Boost circuit input voltage excitation figure; Fig. 5 (b) Boost circuit output voltage response diagram.

The schematic diagram of Fig. 6 energy buffer.

Equivalent circuit diagram during Fig. 7 capacitor charging.

The elementary discharge principle figure of Fig. 8.

Embodiment

Below in conjunction with accompanying drawing the invention is described in further details.

The general structure of system as shown in Figure 1.The voltage that storage battery provides " is pressed into " follow-up " energy buffer " by a 400W small-power booster circuit with the high voltage energy; " energy buffer " high voltage appearance energy is discharged by intermittence, so that output power reaches 1200W; The energy buffer protective circuit is responsible for protecting energy buffer not disturbed puncture by follow-up high pressure; Buffer energy measurement circuit is responsible for the energy in " energy buffer " is carried out measures of quantization; The control CPU of system is responsible for whole circuit is coordinated control.

The Boost booster circuit that is based on chip UC3843 that 400W small-power booster circuit partly adopts.In all direct current conversion methods, this technology provides the highest power supply conversion efficiency.Compared to linear voltage regulator and electric charge topology, 400W small-power booster circuit can provide high efficiency in broader loading range, and high power supply conversion efficiency can reduce to minimum with heat dissipation problem.Energy loss is less, also can and then prolong the operating time of product.Schematic diagram such as Fig. 2 of 400W small-power booster circuit show, comprise the element of 12V power supply, chip UC3843, Boost variator circuit and the protective circuit that some are necessary.

The Boost transducer is a kind of switch DC booster circuit, and output voltage is higher than input voltage, and basic circuit is seen Fig. 3.Suppose that switch (triode or metal-oxide-semiconductor) has disconnected for a long time, all elements are in perfect condition, and capacitance voltage equals input voltage, with two these circuit of process analysis of charging and discharging.

Charging processIn charging process, switch on (triode conducting), switch (triode) are located to replace equivalent circuit Fig. 4 (a) with wire.At this moment, input current flows through inductance.

Diode prevents that electric capacity from discharging over the ground.Because input is direct current, so the electric current on the inductance increases so that certain ratio is linear, and this ratio is relevant with the inductance size.Along with inductive current increases, some energy have been stored in the inductance.

Discharge processIn the discharge process, switch disconnects (triode cut-off), equivalent circuit Fig. 4 (b).Because the retention performance of inductive current, the current value of the inductance of flowing through can not become 0 at once, but the value when complete by charging lentamente becomes 0.Circuit originally disconnects, and inductance can only discharge by novel circuit, and namely inductance begins to capacitor charging, and the electric capacity both end voltage raises, and this moment, output voltage was higher than input voltage, and it is complete to rise electricity.

Inductance absorbed energy during charging, inductance gives off energy during discharge.If electric capacity is enough large, output terminal keeps a lasting electric current in discharge process so.If the process of switching electricity constantly repeats, just can obtain being higher than at the electric capacity two ends voltage of input voltage.

The UC3843 control chip is a kind of current source PWM power supply chip, and operating voltage is 12V, and operating current is about 15mA.The oscillator that has a frequency to arrange in the chip; A totem mode export structure that can the source goes out and suck large electric current is specially adapted to the driving of MOSFET; The reference potential of a fixed temperature compensation and high gain error amplifier, current sensor; Have the logical circuit and the PWM comparator that one by one pulse Current limited Control can be provided of latch function, maximum duty cycle can reach 100%.In addition, this chip foot has the internal protection function, such as hysteresis formula under-voltage locking, controllable output Dead Time etc.

Input, output waveform by the Boost circuit simulation of UC3843 control chip control are seen Fig. 5.As shown in Figure 8, when the VDC of input was 12V, after the conversion through the Boost circuit, the VDC of output reached 24V.

" energy buffer " part adopts capacitance energy storage type, by the charging and discharging of capacitor, realizes discharging and recharging igniting process, can produce stronger electrical spark, and the while is simple in structure, performance index are good.

The schematic diagram of energy buffer as shown in Figure 6.Closing Switch , power supply Give electric capacity

Charging,

Be charge protection resistance.Electric capacity

Charge saturated after, Closing Switch simultaneously

,

, power supply

And electric capacity

Simultaneously to load

With Power supply.Charging IGBT conducting, discharge IGBT be the charging process analysis during conducting not, and the equivalent circuit of this moment as shown in Figure 7.Wherein

Be the maximum value of igniting capacitor charging voltage, Be the internal resistance of source,

Be storage capacitor.During capacitor charging, the electric capacity both end voltage

Press exponential increase:

,

Be electric capacity

The time constant of charging circuit.

Work as the duration of charge

The time:

At this moment

The energy that stores is:

Not conducting of charging IGBT, the Discharge process analysis during the discharge IGBT conducting, circuit are as shown in Figure 8.Among the figure

Be resistance,

,

The resistance that the thyristor forward conduction voltage drop forms,

The resistance that wire connector assembly contact voltage forms in the igniting major loop, The elementary resistance of high-tension coil,

Be the primary electrical sensibility reciprocal,

Be storage capacitor.After the IGBT conducting, the electric current that charge coil produces is no longer given electric capacity through the IGBT short circuit

Charging.The spark coil armature winding

, electric capacity

, resistance

Consist of an independently closed-loop path.

Because the ignition coil secondary open circuit is regarded zero output as so can be similar to.So just the spark coil primary circuit discharge process behind the controlled silicon conducting can be regarded as one and have initial energy storage, zero input, zero output

The transient response process.

The time,

The expression time, listed by Kirchhoff's second law:

Will

The substitution following formula, then:

Wherein,

Be the time dependent voltage of electric capacity;

Be the time dependent electric current of inductance.

Order:

,

The expression damping constant,

The expression natural frequency;

Only discuss and work as

Situation, namely

Solve:

Parameter in the formula:

,

Expression amplitude fading index,

The expression initial phase, The expression time;

In the process of vibration, because resistance is constantly at consumed energy, so stored energy reduces gradually in the loop.For the loss that makes ignition energy reduces, need by increasing

Perhaps reduce

Reduce

Feasible way reduces exactly

, for

Can select the little thyristor of forward conduction voltage drop, be typically chosen under the 3A electric current pressure drop less than the thyristor of 1.2V.For

, reduce the connector assembly number in the time of design as far as possible, strengthen the wire diameter in the loop, shorten the ignition circuit conductor length.For , select the copper enameled cable of high-quality in the time of design, can reduce impedance.Select through test, selected

According to energy theorem:

The integration simplification obtains

This formula is the energy expression formula of primary air.Can find out, the electric capacity of primary circuit is larger, inductance is less, more is conducive to improve ignition energy.But in order to improve the electric speed of discharging and recharging of electric capacity, electric capacity can not unconfinedly increase again.Select through test, selected

Experiment showed, different duration of charge, discharge time and discharge time so that the igniting phenomenon is different.

(1) keeps discharge time and discharge time constant, change the duration of charge.

Duration of charge/ms	Corresponding ignition energy/mJ
		0.01	22.5
0.05	33.17
		0.1	35.77
0.3	42.13
		0.5	46.93
1	58.83
		2	56.2
3	54.13
		4	55.1
5	55.65

Annotate: 1) 24V charging voltage; 2) total cycle 100ms; 3) discharge time 2ms; 4) discharge time is 1 time.

(2) keep duration of charge and discharge time constant, change discharge time.

Annotate: 1) 24V charging voltage; 2) total cycle 100ms; 3) discharge time is 1 time.

(3) different duration of charge and discharge time, corresponding different discharge times.

Annotate: 1) 24V charging voltage; 2) total cycle 100ms.

Systems control division divides employing single-chip microcomputer and IGBT to cooperate, and realizes the control of capacitor discharge by single-chip microcomputer output pulse signal control IGBT break-make.

Single chip part adopts the single-chip microcomputer of STC89C52RC model, this model single-chip microcomputer stable performance, has stronger antijamming capability, is furnished with 8K byte FLASH, 512 byte RAM, cooperate self-defining delay function, the highlyest produce the pulse signal that frequency is 1000Hz, substantially satisfy program and requirement of experiment.

In this control circuit, use two I/0 interfaces and IGBT to cooperate, control respectively the control that the IGBT break-make realizes the electric capacity charge and discharge by the single-chip microcomputer output pulse signal.

Claims

1. self adaption high-energy ignition system; it is characterized in that comprising storage battery, 400W small-power booster circuit, energy buffer, energy buffer protective circuit, buffer energy measurement circuit and the control CPU of system; wherein; storage battery, 400W small-power booster circuit and energy buffer are linked in sequence; energy buffer protective circuit, energy buffer and buffer energy measurement circuit are linked in sequence, and buffer energy measurement circuit, the control CPU of system and 400W small-power booster circuit are linked in sequence.