CN2539343Y

CN2539343Y - High-power dc proportional power

Info

Publication number: CN2539343Y
Application number: CN 02219859
Authority: CN
Inventors: 张健; 曹良
Original assignee: Changzhou Power Supply Co of Jiangsu Electric Power Co
Current assignee: Changzhou Power Supply Co of Jiangsu Electric Power Co
Priority date: 2002-04-08
Filing date: 2002-04-08
Publication date: 2003-03-05
Anticipated expiration: 2012-04-08

Abstract

The utility model relates to a direct current power supply, in particular to a high power direct current ratio power supply, which comprises a direct current input terminal and a direct current output terminal. A switching power supply realizing a voltage reduction function is reversely connected between the direct current input terminal and the direct current output terminal in series, to realize subtraction superposition of the output voltage and the direct current input voltage of the switching power supply, and to ensure the switching power supply to output the required and adjustable 80 percent Ue plus or minus 10 percent voltage, thus when a full group interlock test is performed, and the voltage reduction adjustment to the voltage of a whole direct current bus is not needed, thereby avoiding the refuse operation and the miss operation failure of relay protection equipment, communication equipment, high-voltage switches, and other equipment in service because of the adjustment of the voltage of the direct current, and having use safety and reliability.

Description

High power DC ratio power supply

Technical field

The utility model relates to a kind of DC power supply, relates in particular to a kind of high power DC ratio power supply.

Background technology

The relay protection equipment of electric power system and control loop need provide the 80%Ue direct voltage to do whole group linkage test when operation and periodic check.But what generally adopt at present is that to be adjusted downward to voltage be 80%Ue for DC bus-bar voltage with whole electric substation; so when a certain electric unit is carried out verification; can directly influence normal operation such as relay protection device in service, communication apparatus and high-voltage switch gear; even generation tripping and malfunction; reduce the reliability of relaying protection, had a strong impact on the normal operation of whole electric power networks.

Technical scheme

The utility model is for solving above-mentioned deficiency, provide a kind of safe and reliable, can not regulate DC bus-bar voltage and the high power DC ratio power supply of required voltage ratio is provided separately.

The technical scheme that the utility model addresses the above problem is: a kind of high power DC ratio power supply, comprise a direct-flow input end and a dc output end, and between direct-flow input end and dc output end, oppositely be connected in series the Switching Power Supply of a realization hypotensive effect.

Above-mentioned Switching Power Supply comprises that the sample circuit, comparison circuit, the IC3 chip that link to each other successively are main control circuit for pulse-width modulation and semibridge system translation circuit and current rectifying and wave filtering circuit.

Advantage after the novel employing technique scheme of this reality is: owing to oppositely be connected in series the Switching Power Supply of a realization hypotensive effect between direct-flow input end and the dc output end; after making the output voltage and DC input voitage subtraction superposition of Switching Power Supply; export required adjustable 80%Ue voltage; so when doing whole group linkage test; need not be again the voltage of whole dc bus be carried out reduction regulation; therefore avoided operating relay protection device, communication apparatus and high-voltage switch gear etc., because of the adjusting of DC bus-bar voltage produces tripping and malfunction fault.This device is safe and reliable, applicable to input voltage in the scope of 48V～220V.

Description of drawings

Fig. 1 is a theory diagram of the present utility model.

Fig. 2 is a block diagram of the present utility model.

Fig. 3 is the electrical schematic diagram of embodiment of the present utility model.

Embodiment

See Fig. 1,3 vast scale DC power supply of the present utility model, comprise a direct-flow input end and a dc output end, between direct-flow input end and dc output end, oppositely be connected in series the Switching Power Supply 1 of a realization hypotensive effect, with the output voltage system and former DC input voitage subtraction superposition that a Switching Power Supply 1 is provided, export the voltage of required ratio.See Fig. 2,3 Switching Power Supplies 1 of the present utility model comprise successively the sample circuit 1-1, the comparison circuit 1-2 that link to each other, based on control circuit for pulse-width modulation 1-3 and the semibridge system translation circuit 1-4 and the current rectifying and wave filtering circuit 1-5 of IC3 chip.

Comprise the output current sample resistance R7 that is arranged between direct-flow input end negative pole and the dc output end negative pole as Fig. 3 sample circuit 1-1 of the present utility model, be arranged on the output voltage of forming by resistance R 5 and resistance R 6 sampling on the dc output end; Be arranged on the resistance R 1 of direct-flow input end, the input voltage sampling that R2 forms; And be arranged on the reference voltage sampling that resistance R 3 between IC3 chip voltage reference edge and the ground and R4 form.

See that Fig. 3 comparison circuit 1-2 of the present utility model is made of comparator IC1 and comparator IC2, comparator IC1 and IC2 can adopt integrated operatinoal amplifier or integrated comparator, as LM339 or LM393 etc., comparator IC1 inverting input is connected between resistance R 1 and the R2, by resistance R 1 and R2 input voltage is taken a sample, comparator IC1 in-phase input end connecting resistance R5, between the R6, wherein resistance R 5 is an adjustable resistance, its resistance of scalable is to change the ratio value of output voltage as requested, take a sample by resistance R 5 and 6 pairs of output voltages of resistance R, the pulse width modulation controlled pin of its output termination IC3 chip, comparator IC1 carries out sampling rate to input voltage and output voltage, and to output voltage carry out from motion tracking, signal after the comparison is transported to the IC3 chip, with the driving pulse width of adjusting IC3 chip output, thus the output voltage of adjustment Switching Power Supply 1.Comparator IC2 in-phase input end is connected between the negative pole and resistance R 5 of dc output end; inverting input is connected between resistance R 3 and the R4; its output termination IC3 chip forbid exporting control pin; by comparator IC2 output current sampling value and reference voltage are compared; when overload takes place when; close the pulse output end of IC3 chip, Switching Power Supply 1 is quit work, finish overcurrent protection.

The IC3 chip of present embodiment can adopt M496 or other pulse width modulator.See that Fig. 3 semibridge system translation circuit of the present utility model 1-4 is made of capacitor C 1, C2, C3 and triode Q1, Q2, the former limit of transformer T1, two pulse output pins of IC3 chip link to each other with the base stage of triode Q1, Q2 respectively, triode Q1 collector electrode connects positive pole, the grounded emitter of triode Q2, one end of capacitor C 3 links to each other with the emitter of triode Q1, the collector electrode of Q2, the other end links to each other with the former limit of transformer T1, and the point of contact of capacitor C 1 and capacitor C 2 connects the lower end on the former limit of transformer T1.By capacitor C 1, C2 input voltage is carried out dividing potential drop, to reduce triode Q1, Q2 requirement of withstand voltage, the conducting of IC3 chip drives pulse square wave output pin control triode Q1 and Q2 simultaneously and and close and output high frequency square wave.The CL filter circuit that single-phase full-wave rectifer circuit that current rectifying and wave filtering circuit is made of transformer T1 secondary and diode D2, D2 and the inductance L 1 that is serially connected in capacitor C 4 front portions constitute is formed, the secondary of transformer T1 induces high frequency square wave, behind diode D2, D2 and inductance L 1, capacitor C 4 and resistance R 8 rectifying and wave-filterings, the voltage of output 20%Ue ± 10%, by with the direct voltage subtraction superposition of input, export the voltage of required 80%Ue ± 10%.

During the utility model work, the DC control plug-in strip or the fuse of Awaiting Overhaul unit are disconnected, insert the input of the utility model direct current ratio power supply, the voltage of Switching Power Supply 1 work and output 20%Ue ± 10% is exported 80%Ue ± 10% voltage of required ratio with former direct current input current subtraction superposition.

Claims

1, a kind of high power DC ratio power supply is characterized in that: comprise a direct-flow input end and a dc output end, oppositely be connected in series the Switching Power Supply (1) of a realization hypotensive effect between direct-flow input end and dc output end.

2, high power DC ratio power supply according to claim 1 is characterized in that: described Switching Power Supply (1) comprises successively the sample circuit (1-1) that links to each other, comparison circuit (1-2), based on control circuit for pulse-width modulation (1-3) and the semibridge system translation circuit (1-4) and the current rectifying and wave filtering circuit (1-5) of IC3 chip.

3, high power DC ratio power supply according to claim 2, it is characterized in that: sample circuit (1-1) comprises the output current sample resistance R7 that is arranged between direct-flow input end negative pole and the dc output end negative pole, be arranged on the output voltage of forming by resistance R 5 and resistance R 6 sampling on the dc output end, be arranged on the input voltage sampling that the resistance R 1, R2 of direct-flow input end are formed, and be arranged on the reference voltage sampling that resistance R 3 between IC3 chip voltage reference edge and the ground and R4 form.

4, according to claim 2 or 3 described high power DC ratio power supplys, it is characterized in that: described comparison circuit (1-2) is made of comparator IC1 and comparator IC2, comparator IC1 inverting input is connected between resistance R 1 and the R2, between in-phase input end connecting resistance R5, the R6, the pulse width modulation controlled pin of its output termination IC3 chip; Comparator IC2 in-phase input end is connected between the negative pole and resistance R 7 of dc output end, and inverting input is connected between resistance R 3 and the R4, its output termination IC3 chip forbid exporting control pin.

5, high power DC ratio power supply according to claim 2, it is characterized in that: described semibridge system translation circuit (1-4) is made of capacitor C 1, C2, C3 and triode Q1, Q2, the former limit of transformer T1, the pulse output end of IC3 chip links to each other with the base stage of triode Q1, Q2 respectively, triode Q1 collector electrode connects positive pole, the grounded emitter of triode Q2, one end of capacitor C 3 links to each other with the emitter of triode Q1, the collector electrode of Q2, the other end links to each other with the former limit of transformer T1, and the point of contact of capacitor C 1 and capacitor C 2 connects the lower end on the former limit of transformer T1.