CN1127952A

CN1127952A - Low voltage DC frequency changer for vehicle

Info

Publication number: CN1127952A
Application number: CN 95116792
Authority: CN
Inventors: 刘海先
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-10-26
Filing date: 1995-10-26
Publication date: 1996-07-31
Anticipated expiration: 2015-10-26
Also published as: CN1042279C

Abstract

The invention relates to a vehicle used low voltage direct current frequency conversion device, which is characterized in that the device leads the direct current power supply to pass through an anti-interference part, and then pass through a direct current driving variable frequency part of the higher voltage output by the voltage boosting part, thus outputting the needed alternating current. As the work mode is a conversion speed adjustment mode when the device is used for starting an alternating current motor, the device suffers little impact, therefore, the power tolerance is greatly reduced, the manufacturing cost is reduced, and the reliability is improved. The device of the invention can be used for various vehicles pulled by railway diesel locomotive, trucks and other occasions where only direct current power source is available but alternating current driving alternating current motor is needed.

Description

Low voltage DC frequency changer for vehicle

The present invention relates to a kind of DC frequency changer, specifically, the low-voltage dc power supply that provides in diesel locomotive, automobile waited for bus is provided converts air-conditioning system in buying car in installments, the converter plant of the AC power that the alternating current motor of refrigerator etc. is used to.

The rail traction vehicle, for example the power supply that provides of diesel locomotive is direct current 96V, fluctuation range is generally 80-130V.Except that many DC motor are arranged, also must use various alternating current motors sometimes on the vehicle, air-conditioning system for example, refrigerators etc. are not always the case.The AC power that DC power supply is transformed into of prior art adopts inverter usually, directly direct current is become alternating current 220V that fixed frequency is 50Hz or 60Hz or 380V etc.The above-mentioned DC-AC scheme that is simply referred to as, impulse current was very big when its shortcoming was electric motor starting, often therefore caused inverter to damage.For this reason, used inverter need have very big margin of power, and this can make the inverter cost rise greatly.

The purpose of this invention is to provide a kind of low voltage DC frequency changer for vehicle,, drive common frequency converter again in order to the DC power supply that can provide in the car is boosted, thus output AC power source.

The present invention seeks to realize like this: a kind of low voltage DC frequency changer for vehicle, it comprises the DC frequency-changing part, it is characterized in that DC power supply puts at least one part of boosting by at least one anti-interference part, and will the raise DC driven frequency conversion part of voltage of the above-mentioned part of boosting is transformed into required AC power to direct current.Technique scheme of the present invention is the low-voltage dc power supply that can provide in the vehicle, by DC boosting, drives frequency converter commonly used again, can be referred to as the DC-DC-AC scheme and finish and be transformed into that alternating current motor uses in the AC power supply vehicle.This is a kind of improvement with remarkable result.

By above-mentioned DC-DC-AC technical scheme, the alternating current source of apparatus of the present invention output is when being used for actuating motor, and because of the speed that modifies tone, the DC-DC part is hit very little, so margin of power needn't be very big, so just can reduce the manufacturing cost of converter plant.Be very ripe frequency converter also, so reliability is very high owing to this installs used technology.Device of the present invention can be used on the railway by the various vehicles of diesel locomotive traction, all kinds of automobile and other occasion of having only DC power supply and needing alternating current driving alternating current machine.

Below with reference to accompanying drawings, describe low voltage DC frequency changer for vehicle of the present invention in detail.

Fig. 1 is the circuit theory diagrams of one embodiment of the present of invention;

Fig. 2 is the another kind of circuit diagram that part adopts that boosts among above-mentioned Fig. 1;

Fig. 3 is another circuit diagram that part adopts that boosts among above-mentioned Fig. 1;

At first, the electrical schematic diagram of one embodiment of the present of invention is described with reference to Fig. 1.As shown in Figure 1, wherein dashed rectangle [I] is represented anti-interference part, the filter network that it is made up of inductance L 1, capacitor C 1 and adjustable resistor W.Iron inductance L1 one termination DC power supply anode, another termination capacitor C 1 and adjustable resistor W, capacitor C 1 then is connected with the DC power supply negative terminal with this resistor W other end.Those skilled in the art is clear, and the anti-interference network of being made up of inductance, electric capacity and resistance of filtering has a variety of, but also can have multistage.

Dashed rectangle shown in Figure 1 [II] expression DC boosting part.This part of boosting is a kind of by inductance L 2, triode T1, the typical paralleling switch voltage-stabilized power supply circuit that diode D1, resistance R 2 and R3 and capacitor C 2 constitute or be referred to as booster converter.The end A of this inductance L 2 connects the direct voltage anode of anti-interference part, and the positive pole of another terminating diode D1 of L2 and the collection utmost point of triode T1.The negative pole of this diode D1 output be the positive terminal C of the direct voltage that boosted.Be connected to resistance R 2 and the R3 that connects between this positive terminal C and negative terminal D, and capacitor C 3.Triode T1 is as switch element, and its base stage connects the control signal output ends of controller, and its emitter-base bandgap grading is connected with negative terminal D (being B).Also have, the input voltage of this controller is taken from the node between resistance R 2 and R3.The above-mentioned part of boosting is work like this, and when the control signal of controller made transistor T1 conducting, the electric current that DC power supply provides flow through inductance L 2, and energy storage is in inductance L 2.When triode T1 was turned off, inductance L 2 gave off energy, and flow through diode D1 DC power output, and the voltage of output is greater than the input voltage several times.The part antijamming capability that boosts of this device is very strong.This is owing to when power input has high voltage to scurry into, can directly export to power supply from diode D1, and triode T1 can automatically shut down.As for controller, it can adopt the typical integrated circuit unit of UC3842 or TI494 and so on.

Dashed rectangle shown in Figure 1 (III) expression frequency conversion part.This frequency conversion part can adopt commercially available common frequency converter, the for example GP of Fuji (FUJI), E7 Series Frequency Converter, perhaps three SVF, the MF Series Frequency Converter of cultivating (SANKEN) are directly received between the end C and D of the part of boosting, and the DC converting of the voltage that raise is become for the required AC power of alternating current motor.

Then, the another kind of circuit that the part of boosting in the converter plant of the present invention adopts is described with reference to Fig. 2.Circuit among this figure is a kind of forward conversion type booster circuit.The primary coil one termination triode T2 collection utmost point of transformer Tr1, the emitter-base bandgap grading of T2 connects diode D2 positive pole, and the other end that the negative pole of D2 is received the Tr1 primary coil again constitutes the loop.The base stage of triode T2 connects the control signal output ends of controller, and the input of controller then connects series resistance R4 between dc output end C and D and the node between R5.The anode A of input is positioned at the mid point of the primary coil of transformer Tr1, and negative terminal B is the emitter-base bandgap grading of diode D2 positive pole, triode T2 and the common node of controller.One end of the secondary coil of this transformer Tr1 is connected in series forward diode D3 and inductance L 3 successively, and the other end of inductance L 3 is as direct current output plus terminal C.Between dc voltage output end C and D, meet the resistance R 4 and the R5 of capacitor C 3 and serial connection.In addition, the node 3 of diode D3 and inductance L is provided with a voltage stabilizing didoe D4.Above-mentioned circuit is like this work, and when triode T2 conducting, it is secondary that transformer Trl elementary passed to energy, and boost.Triode D3 conducting this moment, secondary inductance L 3, capacitor C 3 are filtering system, can obtain level and smooth direct current.When triode T2 turn-offed, the stored energy such as leakage inductance among the transformer Tr1 reclaimed by diode D2 with going into.

Then, another booster circuit of the present invention is described with reference to Fig. 3.This is a kind of changing type booster circuit of recommending.The structure of this circuit is as follows: two triode T3 and T4 that push-pull type connects, its collection utmost point is by the primary coil interconnection of transformer Tr2.The emitter-base bandgap grading of this Tr2 primary coil mid point and this T3 and T4 interconnection is respectively the anode A and the negative terminal B of direct current input.The two-phase revertive control signal output part of controller is received the base stage of triode T3 and T4 respectively.The secondary coil two ends of transformer Tr2 are connected in series forward diode D5, a D6 respectively, and the negative pole of this D5 and D6 all is connected with an end of inductance L 4, and the other end of this inductance L 4 is as direct current output plus terminal C.In addition, the secondary coil mid point of transformer Tr2 is as output negative terminal D.The resistance R 6 and the R7 of capacitor C 4 and series connection are connected between output C and the D.The node output voltage of series resistance R6 and R7 is added on the comparator of controller input.

By top specific embodiment device of the present invention is described, should think that the present invention only limits to this.Those skilled in the art can also have the design of the part of boosting according to the present invention and make various modifications and modification.For example use full-bridge or semibridge system booster circuit.Therefore, these should not thought and have broken away from the design scope that is defined by the claims of the present invention.

Claims

1, a kind of low voltage DC frequency changer for vehicle, it comprises the DC frequency-changing part, it is characterized in that DC power supply puts at least one part of boosting by at least one anti-interference part, and will the raise DC driven frequency conversion part of voltage of the above-mentioned part of boosting is transformed into required AC power to direct current.

2,, it is characterized in that the above-mentioned part of boosting is a kind of paralleling switch voltage-stabilized power supply circuit according to the converter plant of claim 1.

3, converter plant according to claim 1, it is characterized in that above-mentioned paralleling switch voltage-stabilized power supply circuit is by inductance L 2, transistor T1, diode D1, controller, resistance R 2 and R3 and capacitor C 1 constitute, one end of above-mentioned inductance L 1 is the anode of direct current input, the positive pole of another terminating diode D1 and the collection utmost point of triode T1, the resistance R 2 and R3 and the capacitor C 3 that are connecting series connection between the anode of above-mentioned output and the negative terminal, receive the control signal output ends of controller as the base stage of the triode T1 of switch, and emitter-base bandgap grading is connected with the output negative terminal, and the voltage input end of above-mentioned controller and series resistance R2 are connected with node between R3.

4,, it is characterized in that the above-mentioned part of boosting is a kind of forward conversion type booster circuit according to the converter plant of claim 1.

5,, it is characterized in that the above-mentioned part of boosting is a kind of changing type booster circuit of recommending according to the converter plant of claim 1.