CN1310409C

CN1310409C - DC/DC Boost Converter

Info

Publication number: CN1310409C
Application number: CNB021490473A
Authority: CN
Inventors: 张耀仁; 吴晋昌; 周宏亮; 阙明宏
Original assignee: Ablerex Electronics Co Ltd
Current assignee: Ablerex Electronics Co Ltd
Priority date: 2002-11-20
Filing date: 2002-11-20
Publication date: 2007-04-11
Anticipated expiration: 2022-11-20
Also published as: CN1503441A

Abstract

The invention discloses a DC/DC boost conversion device, which comprises an inductor, a power electronic switch, a control circuit, a first diode, a second diode and a capacitor. The inductor and the power electronic switch are connected in series and bridged with an input direct current power supply, and the control circuit is connected with the power electronic switch. The first diode is bridged at the joint of the inductor and the power electronic switch and the positive end of the output end. The parallel connection of the capacitor and the second diode is bridged between the positive end of the input end and the positive end of the output end. The DC/DC boost conversion device of the invention can provide a more stable DC voltage, so that the supplied load is not influenced by the voltage drop of the DC voltage source, and the efficiency is higher than that of the existing DC/DC boost conversion device.

Description

The dc/dc boost conversion equipment

Technical field

The present invention relates to a kind of dc/dc boost conversion equipment, specially referring to be applied in provides one than the galvanic current pressure in the electronic circuit, make the load of supply not be subjected to the DC/DC conversion device that direct voltage source voltage descends to be influenced.

Background technology

General direct voltage source can be supplied with by ac/dc rectifier or storage battery, load is then taken out direct current energy from this direct voltage source and is used, on motor driver or uninterruptible power system, this load can be an inverter (inverter) for the motor driven power supply or supply with high-quality AC energy, this load also can be other DC load, and no matter which kind of load all must just can be kept normal running in a certain voltage range.Yet this ac/dc rectifier is supplied with direct voltage source owing to be subjected to the unusual low-voltage of AC power, causes its direct voltage source of supplying with also to produce low-voltage; Same, then may cause its direct voltage source of supplying with also to produce low-voltage, and these low-voltage states all may cause the misoperation of follow-up power consumption equipment if supply with direct voltage source owing to influenced by the deep discharge of storage battery own with storage battery.In order to solve the problem that direct voltage source generation voltage descends, utilize adding one direct current/DC voltage booster circuit to come to deal with the voltage decline problem of this direct voltage source, to keep the normal operation of load.

Fig. 1 discloses the circuit diagram of existing dc/dc boost circuit.Please refer to shown in Figure 1ly, one direct current/DC voltage booster circuit 1 places between input dc power potential source Vin and the output end vo ut, and it comprises an inductor 10, an electronic power switch 11, a diode 12 and a capacitor 13.When these electronic power switch 11 closures, this inductor 10 charges.When this electronic power switch 11 disconnected, the charging of this inductor 10 was converted to this capacitor 13 through this diode 12 and charges and use for load.By closure and the opening time of controlling this electronic power switch 11, can provide a voltage that is higher than input dc power potential source Vin at the output end vo u of this dc/dc boost circuit 1.No matter the voltage of this input dc power potential source Vin is normal, or this input DC power vin descends because of unusual low-voltage of the alternating voltage of ac/dc rectifier or storage battery deep discharge etc. cause voltage, this dc/dc boost circuit 1 all keeps running, so the power loss that this dc/dc boost circuit 1 is caused exists always, because direct voltage source produces voltage and drops to anomaly, life period is not long, if this dc/dc boost circuit 1 keeps running will cause whole DC power-supply system efficient to reduce, and the heat increase that this power loss caused also needs bigger heat abstractor to dispel the heat always.

Summary of the invention

The purpose of this invention is to provide a kind of dc/dc boost conversion equipment, direct voltage source just often this DC/DC conversion device do not turn round, this direct voltage source directly provides output voltage through a diode to output, and when the voltage of direct voltage source descends, then utilize this dc/dc boost conversion equipment to descend so that the voltage that overcomes direct voltage source that boosts to be provided, therefore can provide a more stable VD, to improve the reliability of follow-up load electricity consumption.This DC/DC conversion device is running when the voltage of direct voltage source descends only, so that the power loss that this DC/DC conversion device produced can drop to is minimum, to promote the efficient of whole direct-current power supply system.

The present invention is achieved in that

A kind of dc/dc boost conversion equipment, it comprises with the lower part: whether a control circuit in order to the input voltage of the input that detects this conversion equipment and the output voltage of an output, is lower than a predetermined voltage to judge this input voltage; This control circuit comprises one first voltage detector, a subtracter, a controller, a comparator, a high frequency triangle wave generator, one second voltage detector, a hysteresis comparator, one and a door and an electronic power switch drive circuit; One electronic power switch is connected to this control circuit, is determined the state of this electronic power switch by this control circuit; One inductor, the back cross-over connection of connecting with electronic power switch in input DC power to charge and to discharge: one first diode cross-over connection is between the anode of the junction of this inductor and this electronic power switch and output; One capacitor, cross-over connection is between the anode of the anode of input and output; And one second diode, be connected in parallel with this capacitor; The output end voltage of this dc/dc boost conversion equipment is this input DC power voltage and this condenser voltage sum, and a voltage that is higher than this input DC power voltage can be provided; This first voltage detector detects output voltage, through this subtracter, controller and high frequency triangle wave generator be connected to this comparator and obtain a pulse-width modulation signal deliver to this with the door an input; This second voltage detector detects this input DC power voltage, is connected to this and another input of door through this hysteresis comparator, should be connected to this electronic power switch with door output; This control circuit is that this input DC power voltage is judged relatively that with a high/low reference voltage this input DC power voltage is normal condition or low-voltage state respectively; When this input DC power voltage is normal condition, keeps this electronic power switch and disconnect; When this input DC power voltage is low-voltage state, controls this electronic power switch and do the pulse-width modulation switching.

According to dc/dc boost conversion equipment of the present invention, this device has an input and an output, and this device comprises an inductor, an electronic power switch, a control circuit, one first diode, one second diode and a capacitor.This input is connected to a direct current voltage source, and this direct voltage source can be ac/dc rectifier or storage battery, and this output is received load, and this load can be inverter or other DC load; This inductor and electronic power switch series connection cross-over connection are in this input DC power, and this control circuit is connected in this electronic power switch, and this first diode cross-over connection is in the anode of this inductor and electronic power switch junction and this output.The cross-over connection in parallel of this capacitor and second diode is between the anode of the anode of this input and this output.This control circuit utilizes a voltage hysteresis comparator that input direct voltage is divided into a high reference voltage and a low reference voltage is made comparisons, when being higher than a high reference voltage, input direct voltage regards as normal condition, this control circuit is controlled an electronic power switch and is kept to disconnect and be failure to actuate, thereby do not carry out boost action, input direct voltage directly exports load to via this second diode, and output end voltage approximates input dc power potential source voltage.When input direct voltage is lower than this low reference voltage, regard as low-voltage state, this control circuit is controlled this electronic power switch and is done the pulse-width modulation switching, and when this electronic power switch was closed, this inductor charged; When this electronic power switch disconnects, the electric energy of this inductor is converted to this capacitor through this first diode and forms a voltage, this second diode is instead ended partially, at this moment, this output output voltage is the voltage of this input direct voltage and the series connection of this condenser voltage, therefore can reach the effect of boosting.

Because of DC/DC conversion device of the present invention has the function of boosting, therefore can make the working range of input direct voltage quite wide, avoid its power consumption equipment to cause misoperation because of the input voltage source low-voltage.In addition, this DC/DC conversion device only turns round under the input voltage source low-voltage, just often then do not turn round in order to avoid this DC/DC conversion device is operated the power loss that is caused always at input voltage source, therefore can effectively promote the efficient of whole direct-current power supply system.

The present invention utilizes the dc/dc boost conversion equipment to provide one than the galvanic current pressure, not influenced by the voltage decline of direct voltage source; And at DC power supply voltage just often, this dc/dc boost conversion equipment of shut-down operation is to avoid the outer power loss of amount.

Description of drawings

Fig. 1 is the circuit diagram of existing dc/dc boost circuit;

Fig. 2 is the circuit diagram of preferred embodiment dc/dc boost conversion equipment of the present invention;

Fig. 3 is the control calcspar of preferred embodiment dc/dc boost conversion equipment of the present invention;

Fig. 4 is the preferred embodiment that dc/dc boost conversion equipment of the present invention is applied in two direct voltage origin systems.

Symbol description:

1 dc/dc boost circuit, 10 inductors, 11 electronic power switches

12 utmost point pipes, 13 capacitors

2 dc/dc boost conversion equipments

21 inductors, 22 electronic power switches, 23 control circuits

230 first voltage detectors, 231 subtracters, 232 controllers

233 comparators, 234 high frequency triangle wave generators

235 second voltage detectors, 236 hysteresis comparators 237 and door

238 electronic power switch drive circuits, 24 first diodes, 25 second diodes

26 capacitors, 3 inputs, 4 outputs

5 first direct voltage sources, 6 second direct voltage sources, 7 diodes

8 inverters, 9 AC load

50 ac/dc rectifiers, 51 filtering capacitors

Embodiment

In order to allow above-mentioned and other purposes of the present invention, feature and advantage understand by clearer and more definite quilt, hereinafter will be especially exemplified by preferred embodiment of the present invention, and cooperate appended legend, be described in detail below:

Fig. 2 discloses the circuit diagram of preferred embodiment dc/dc boost conversion equipment of the present invention; And Fig. 3 discloses the control calcspar of preferred embodiment dc/dc boost conversion equipment of the present invention.

Please refer to shown in Figure 2, the dc/dc boost conversion equipment 2 of preferred embodiment of the present invention has an input 3 and an output 4, this input 3 is connected to a direct current voltage source, this direct voltage source can be the ac/dc rectifier or storage battery provides, this output is received load, this load can be inverter or other direct-flow electricity utilization apparatus, because the action of this dc/dc boost conversion equipment 2, make output 4 that a more stable VD supply load can be provided, so that load avoids being subjected to the influence of input dc power potential source low-voltage and causes misoperation.

Referring again to shown in Figure 2, this dc/dc boost conversion equipment 2 comprises an inductor 21, an electronic power switch 22, a control circuit 23, one first diode 24, one second diode 5 and a capacitor 26.On circuit framework, the series connection cross-over connection of this inductor 21 and electronic power switch 22 is in this input 3, and this control circuit 23 is connected in this electronic power switch 22.These first diode, 24 cross-over connections are in the anode of this inductor 21 and electronic power switch 22 junctions and this output 4.The parallel connection of this capacitor 26 and second diode 25 then cross-over connection between the anode of the anode of this input 3 and this output 4.

Please refer to shown in Figure 3ly, this control circuit 23 comprises one first voltage detector 230, a subtracter 231, a controller 232, a comparator 233, a high frequency triangle wave generator 234, one second voltage detector 235, a hysteresis comparator 236, one and door 237 and one electronic power switch drive circuit 238.

Please refer to Fig. 2, shown in Figure 3, this first voltage detector 230 is connected to this output 4, out detects with output voltage V, export the negative terminal of this subtracter 231 again to, the anode of this subtracter 231 then connects a setting voltage Vset, both subtract each other and obtain the result and export this controller 232 to and compensate adjustment to obtain one first control signal S1, and this setting voltage Vset is the desired value of output dc voltage.This high frequency triangle wave generator 234 produces a high frequency triangle wave signal, and this high frequency triangle wave signal and the first control signal S1 deliver to this comparator 233 to obtain a pulse-width modulation signal.On the other hand, this second voltage detector 235 detects the input direct voltage Vin of input DC power, and this an input direct voltage Vin and a reference voltage Vref are inputed to this hysteresis comparator 236, so produces one second control signal S2.This second control signal S2 and pulse-width modulation signal are inputed to this and door 237, should deliver to this electronic power switch drive circuit 238 with door 237 output signals and export this electronic power switch 22 to control its closed and disconnection to produce a drive signal.

Please refer to shown in Figure 3ly, this hysteresis comparator 236 produces a high reference voltage and a low reference voltage according to this reference voltage Vref.When the input direct voltage Vin that detects when this second voltage detector 235 is lower than a low reference voltage, the second control signal S2 that this hysteresis comparator 236 produces high levles to should and door 237, make this dc/dc boost conversion equipment 2 activations.On the other hand, output voltage V out and the setting voltage Vset that detected by this first voltage detector 230 this moment compare, and both subtract each other the result and export this controller 232 to produce the first control signal S1.This first control signal S1 exports this comparator 233 again to and relatively produces the pulse-width modulation signal in the back with the high frequency triangle wave signal that this frequency triangular wave generator 234 produces.Because this second control signal S2 is high levle, so this pulse-width modulation signal exports this power electronics drive circuit 238 to and drives these electronic power switches 22 and make pulse-width modulation and switch.Referring again to shown in Figure 2, when these electronic power switch 22 closures, these inductor 21 chargings, and when this electronic power switch 22 disconnects, the electric energy of this inductor 21 exports this capacitor 26 to form a voltage Vaux via this first diode 24, at this moment, this second diode 25 instead ends partially, and these output 4 output voltages are the input direct voltage Vin of this input 3 and the voltage Vaux series connection formation boost function of this capacitor 26.So when the input direct voltage Vin of this input 3 low-voltage, can reach boost function, run well to avoid these output 4 output LOW voltages to influence load by this dc/dc boost conversion equipment 2.

Referring again to shown in Figure 3, the input direct voltage vin that detects when this second voltage detector 235 gos up when being higher than a high reference voltage, the second control signal S2 of these hysteresis comparator 236 outputs is returned to low level, the second control signal S2 of this low level delivers to this and door 237, should also be converted to low level with door 237 outputs, and make this electronic power switch 22 keep disconnection always.Referring again to shown in Figure 2, when this electronic power switch 22 is kept disconnection always, this dc/dc boost conversion equipment 2 is with anergy, input direct voltage Vin directly outputs to output 4 to supply with load via this second diode 25, this moment, the voltage of output 4 was similar to the voltage that input connects the input dc power potential source, and do not boost, this moment, this dc/dc boost conversion equipment 2 was failure to actuate, and therefore can avoid the power loss of this dc/dc boost conversion equipment action.

Please refer to and Figure 4 shows that dc/dc boost conversion equipment 2 of the present invention is applied in the preferred embodiment of two direct voltage origin systems, comprise an ac/dc rectifier 50 and a filtering capacitor 51 in this first direct voltage source 5, this ac/dc rectifier 50 converts the AC energy that this ac power input end provided to a direct current electric energy, does voltage stabilizing to become this first direct voltage source 5 through this filtering capacitor 51 again; This second direct voltage source 6 is provided by storage battery, and this second direct voltage source 6 is connected with dc/dc boost conversion equipment 2 through this diode 7 and this first direct voltage source 5 again and is connected in parallel to provide one to be higher than under inverter 8 normal runnings required minimum lower voltage limit supply AC load 9 and to use.When this ac power input end provided normal alternating voltage, this first direct voltage source 5 also provided normal direct voltage, and this moment, this dc/dc boost conversion equipment 2 did not act on.The direct voltage that this first direct voltage source provides will be higher than second direct voltage source, 6 voltages, so these diode 7 reverses biased, this moment, inverter 8 required direct current energies were by these first direct voltage source, 5 supplies, when the voltage that provides when this ac power input end produces fault such as low-voltage or power failure, the voltage that this first direct voltage source 5 provides also will descend, if the voltage that the voltage that provides of this first direct voltage source 5 is lower than this second voltage source 6 then second diode 25 of these dc/dc boost conversion equipment 2 inside and this diode 7 all with forward bias voltage drop and conducting, therefore, these inverter 8 required direct current energies will change by 6 supplies of this second direct voltage source, when the voltage of this second direct voltage source 6 is reduced to the low reference voltage that these dc/dc boost conversion equipment 2 internal control circuits set because of discharge (approximating the following minimum lower voltage limit of inverter 8 normal runnings), then this dc/dc boost conversion equipment 2 produces boost action with activation, makes the direct-flow input end voltage of this inverter 8 can maintain its normal operating limit.When alternating voltage that this ac power input end provided recovers normal, the direct voltage that this moment, this first direct voltage source 5 provided will be higher than the high reference voltage that these dc/dc boost conversion equipment 2 internal control circuits are set, therefore this dc/dc boost conversion equipment 2 no longer acts on, these diode 7 reverses biased, these inverter 8 required direct current energies are once again by these first direct voltage source, 5 supplies.Because this second direct voltage source 6 connects to provide direct current energy to inverter 8 through this dc/dc boost conversion equipment 2 when the ac power input end fault, therefore when having this dc/dc boost conversion equipment 2 when voltage descends fast because of repid discharge produces, this second direct voltage source 6 assists to boost, therefore, can more make full use of the electric energy of storage battery in this second direct voltage source 6, make this storage battery energy deep discharge, so can adopt less storage battery to be used as second direct voltage source 6.Refer again in the preferred embodiment that dc/dc boost conversion equipment of the present invention shown in Figure 4 is applied in two direct voltage origin systems, when if the direct voltage that storage batterys are supplied in this second direct voltage source 6 is lower than the required minimum lower voltage limit of these inverter 8 normal runnings, then this dc/dc boost conversion equipment 2 will be kept boost action always, arrive more than the required minimum lower voltage limit of these inverter 8 normal runnings with the anode voltage that promotes this diode 7.When this ac power input end provides normal voltage, this first direct voltage source 5 also provides a normal voltage, the normal voltage that this first direct voltage source 5 provides will be higher than the output voltage of this dc/dc boost conversion equipment 2, this diode 7 is a reverse biased, and the required direct current energy of inverter this moment is supplied with by first direct voltage source 5.Therefore, when this ac input end provides voltage to produce low-voltage or fault, this second direct voltage source 6 boosts to the minimum lower voltage limit that is higher than inverter 8 normal runnings through dc/dc boost conversion equipment 2, supply with direct current energy through this diode 7 and use for this inverter 8, make inverter 8 can continue normal running.In this application examples, because second direct voltage source, 6 voltages are lower than the minimum lower voltage limit of these inverter 8 normal runnings, therefore these dc/dc boost conversion equipment 2 permanent activations will not be so second diode 25 in this dc/dc boost conversion equipment 2 will act on.

Though the present invention discloses with aforementioned preferred embodiment, so it is not in order to limiting the present invention, anyly has the knack of this operator, without departing from the spirit and scope of the present invention, and when doing various changes and modification.So the claim that protection scope of the present invention ought be looked in the claims of front is as the criterion.

Claims

1. A DC/DC boost conversion device, characterized in that it comprises the following parts:

A control circuit, used to detect the input voltage of an input end and the output voltage of an output end of the conversion device, to determine whether the input voltage is lower than a predetermined voltage; the control circuit includes a first voltage detector, a subtraction device, a controller, a comparator, a high-frequency triangular wave generator, a second voltage detector, a hysteresis comparator, an AND gate and a power electronic switch drive circuit;

a power electronic switch connected to the control circuit, and the control circuit determines the state of the power electronic switch;

An inductor, connected in series with the power electronic switch across the input DC power supply for charging and discharging:

a first diode connected across the junction of the inductor and the power electronic switch and the positive terminal of the output;

a capacitor connected across the positive terminal of the input terminal and the positive terminal of the output terminal; and

a second diode connected in parallel with the capacitor;

The output terminal voltage of the DC/DC boost conversion device is the sum of the input DC power supply voltage and the capacitor voltage, which can provide a voltage higher than the input DC power supply voltage; the first voltage detector detects the output voltage , connected to the comparator through the subtractor, the controller and the high-frequency triangular wave generator to obtain a pulse width modulation signal and send it to an input terminal of the AND gate; the second voltage detector detects the input DC power A voltage is connected to the other input terminal of the AND gate through the hysteresis comparator, and the output of the AND gate is connected to the power electronic switch;

The control circuit compares the input DC power supply voltage with a high/low reference voltage to determine whether the input DC power supply voltage is in a normal state or a low voltage state; when the input DC power supply voltage is in a normal state, maintain the power electronic switch disconnected; when the input DC power supply voltage is in a low voltage state, the power electronic switch is controlled to perform pulse width modulation switching.

2. The DC/DC boost conversion device as claimed in claim 1, wherein the first diode serves as a path for the inductor to discharge the capacitor.

3. The DC/DC boost conversion device as claimed in claim 1, wherein the second diode serves as a bypass path for the capacitor.

4. The DC/DC step-up conversion device according to claim 1, wherein when the input DC power supply voltage is in a normal state, the power electronic switch is always kept off, and the electric energy of the input DC power supply directly passes through the second Diodes flow to the output without boosting action.

5. The DC/DC step-up conversion device according to claim 1, characterized in that when the input DC power supply voltage is in a low voltage state, the power electronic switch performs pulse width modulation switching, and when the power electronic switch is closed, the inductance When the power electronic switch is turned off, the electric energy of the inductor is discharged to the capacitor through the first diode to form a voltage, so that the second diode is reverse-biased, and the output terminal outputs a voltage is the sum of the input DC voltage source voltage and the capacitor voltage.

6. The DC/DC step-up conversion device according to claim 1, characterized in that when the voltage of the input DC power supply at the input end is lower than the low reference voltage, it is considered as a low voltage state; when the voltage input of the input DC power supply is high A normal state is assumed at the high reference voltage.

7. The DC/DC boost conversion device according to claim 1, wherein when the voltage of the input DC voltage source at the input end is between the low reference voltage and the high reference voltage, the control circuit maintains the original asserted state and does not Change, that is, if it was originally identified as a low-voltage state, it will remain as a low-voltage state, and if it was originally identified as a normal state, it will remain as a normal state, so as to prevent the identification status from changing from time to time.

8. The DC/DC boost conversion device according to claim 1, characterized in that the AND gate output is connected to the power electronic switch driving circuit to generate a driving signal output to the power electronic switch to control the closing of the power electronic switch and disconnect.

9. The DC/DC boost conversion device according to claim 1, wherein when the input DC voltage source is in a normal state, the hysteresis comparator outputs a low level signal, and the AND gate outputs a low level signal , the power electronic switch is turned off.

10. The DC/DC boost conversion device according to claim 1, wherein when the input DC voltage source is in a low voltage state, the hysteresis comparator outputs a high-level signal, and the AND gate outputs a pulse width modulation signal, the power electronic switch performs pulse width modulation switching.

11. The DC/DC boost conversion device according to claim 1, characterized in that the DC/DC boost conversion device can be applied in a dual DC voltage source system, wherein the first DC power supply can be supplied by rectification and filtering of the AC power supply, The second DC power supply can be supplied by a storage battery, the input terminal of the DC/DC boost conversion device is connected to the second DC power supply, and the output terminal of the DC/DC boost conversion device is connected to the first DC power supply through a diode.

12. The DC/DC boost conversion device according to claim 11, characterized in that when the DC/DC boost conversion device is applied in a dual DC voltage source system, the DC/DC boost conversion device will output a voltage higher than the load The voltage of the lower limit voltage for normal operation.

13. The DC/DC boost conversion device according to claim 11, characterized in that when the DC/DC boost conversion device is applied in a dual DC voltage source system, when the first DC power supply is normal, its supply voltage will be higher than The output voltage of the DC/DC boost conversion device, the load is powered by the first DC power supply; when the first DC power supply fails, its supply voltage will be lower than the output voltage of the DC/DC boost conversion device, and the load changes Power is supplied by the second DC power supply through the DC/DC boost conversion device.