CN201029205Y

CN201029205Y - Digital low-voltage compensating device

Info

Publication number: CN201029205Y
Application number: CNU200620036663XU
Authority: CN
Inventors: 谢建洪
Original assignee: Chengdu Kewei Science & Technology Development Co Ltd
Current assignee: Chengdu Tuo Yue Technology Development Co., Ltd.
Priority date: 2006-12-18
Filing date: 2006-12-18
Publication date: 2008-02-27
Anticipated expiration: 2016-12-18

Abstract

The utility model relates to a digital low voltage compensating device which is used for compensating the voltage of the low voltage electric network and characterized in that after connected with an energy storage unit, the input end and the output end of a main loop voltage are connected in parallel with an IGBT boosting chopper module, and then connected in serial with the an IGBT afterflow module and an output filter circuit; the control loop is provided with a sampling and comparing adjustable feedback unit, a singlechip is connected with a control circuit, an IGBT drive circuit, and then connected with the G poles of the IGBT switching elements of the main loop. Because adopting the new power electronic device insulating bipolar transistor IGBT, the load loss of the utility model is less than 3.2 percent, and the output power achieves 22 KW; thereby guaranteeing the electric network has steady and reliable power supply quality, so the utility model no need extend the 10KV circuit, and no need add the electricity transformer, reducing the electric network reformation investment; and the accommodation of the input voltage is between 85 V and 250 V; the numeral shows the input and output voltage, and the output voltage is adjustable; in addition, the utility model has functions of IGBT overloading and over temperature protections, etc. therefore, the digital low voltage compensating device is suitable for being used in the upgrading rural power grids.

Description

Numeral low-voltage compensation arrangement

(1) technical field:

Numeral low-voltage compensation arrangement is a kind of computerizeing control, the device that low-voltage network voltage is compensated.Belong to power supply or power distribution circuit device class (H02J), regulate electric variable class (G05F) and Digital Data Processing Equipment class (G06F).

(2) background technology:

In the transformation process of current rural power grids,, also there is the place that much can't put into the melting pot, causes the rural power grids user to have the normally situation of electricity consumption owing to reasons such as fund and rural power grids dispersivenesses.If adopt the increase traditional transformer can improve situations such as supply power voltage is low, but it is too low to increase the transformer investment yield at the few place that disperses again of certain user's quantity, and can increase circuit no-load loss, causes waste of energy.Existing other compensation class device, as products such as reactive power compensation, harmonic compensations, they can only compensate some certain loads (as inductive load), and can't tell on because of situations such as the oversize supply power voltage that causes of user's dispersive line are low.

(3) summary of the invention:

The digital low-voltage compensation arrangement that the utility model proposes solves the low situation problem of low-voltage network supply power voltage that above-mentioned a variety of causes causes exactly, electrical network is compensated, to improve the rural power grids power supply quality and to reduce investment.Its technical scheme is as follows:

Numeral low-voltage compensation arrangement is provided with voltage input end Ui, voltage output end U ₀, be frequency 50 He Zhi alternating voltages, it is characterized in that: in major loop, behind the voltage input end Ui serial connection energy-storage units 2, parallel IGBT boost chopper module 4, series IGBT afterflow module 5 and output filter circuit 6 again are until voltage output end Uu; In control loop, establish the feedback unit 7 that is connected with output filter circuit, connect cpu control circuit 8 then, the pin of circuit 8 is connected with four groups of IGBT grid G in the IGBT afterflow module with IGBT boost chopper module respectively by IGBT drive circuit 9.

Above-mentioned IGBT full name is a power electronic device of new generation for the insulation bipolar transistor.Electric current by it replaces break-make, makes alternating current produce very high frequency, is generally (20～30) KHz, be up to 100KHz and more than.Here as a high-power high-frequency switch.Generally two groups of IGBT can be set respectively in it in above-mentioned IGBT boost chopper module and the IGBT afterflow module.

Establish the protective circuit that comprises overtemperature and overcurrent protection 10 in the above-mentioned control loop in order to protection IGBT.

The input and output sampling switching circuit that display unit 11 can be set in the above-mentioned control loop and set independent CPUs control circuit 11.4 and be complementary.

Be provided with the potentiometer R that regulates output voltage in the feedback unit 7 of above-mentioned control loop ₇

At above-mentioned input Ui and 2 of energy-storage units and connect by capacitor C ₁Or the input filter circuit of CL formation.

At the input of above-mentioned major loop, output respectively and connect by transient state diode D ₃The anti-surge circuit that constitutes.

Above-mentioned energy-storage units 2 is by the energy storage inductor L that adapts to high-frequency impulse ₂Or inductance L ₂Constitute with the absorption electric capacity of parallel connection.Above-mentioned cpu control circuit 8 is single-chip computer control system.

The utility model beneficial effect:

(1) this patent adopts device IGBT of new generation, and under rated voltage, load loss is less than 3.2%, and power output can be used for poor, the unsettled electrical network of power supply quality rear end up to about 22KW, plays the pressure stabilization function that boosts, and improves rate of qualified voltage; Guaranteed that electrical network has reliable and stable power supply quality.Need not extend the 10KV circuit thus, need not increase distribution transformer newly, for power department is saved a large amount of manpower and materials and significantly reduced investment in upgrading rural power grids.(2) input voltage accommodation is wide: adopt HF switch IGBT power supply, increase filtering and anti-surge circuit, input voltage can provide the steady operation power supply to device in the 85V-250V relative broad range, and assurance device normally moves.(3) the digital input/output voltage that shows: realize by the nixie display 11.6 that the CPU that is provided with controls, make things convenient for the user to check; And adopt the display unit 11 that sets independent CPUs control circuit 11.4, do not influence the actuating speed of host CPU control circuit 8 thus.(4) Adjustable Output Voltage: by the potentiometer R that regulates usefulness is set in the feedback unit ₇, change and the realization of adjusting feedback unit reference voltage.(5) output voltage stabilizing: in feedback unit and cpu control circuit,, realize the output voltage stabilizing by to relatively changing the amplitude of boosting with control output voltage with reference voltage after the sampling filtering of output voltage.(6) be provided with the IGBT element is carried out short circuit, overload and overtemperature prote function, to avoid the damage ring of IGBT; But judgment means and external environment condition abnormal conditions as line short, can be protected the electrical equipment of compensation arrangement and back end subscriber immediately simultaneously.(7) installation is convenient in small volume and less weight.(8) behaviour's part is simple.

(4) description of drawings:

Fig. 1 the utility model block diagram

Fig. 2 the utility model main loop circuit figure (embodiment 1)

Fig. 3 display unit 11 block diagrams (independent CPUs control)

Sample circuit 11.1 circuit diagrams in Fig. 4 display unit 11

Fig. 5 the utility model control loop circuit diagram (comprising

circuit

7,8,9,10)

(5) embodiment:

Embodiment 1: see Fig. 1, Fig. 2, Fig. 3, Fig. 4

See Fig. 2, the following composition of present embodiment major loop: voltage input end Ui connects capacitor C ₁Form input filter circuit 1; The energy-storage units 2 of serial connection adopts chokes energy storage inductor L ₂IGBT boost chopper module 4 in parallel be two-way boost copped wave module 4, i.e. two IGBT elements 4.1 and 4.2, the two-way afterflow module 5 of IGBT afterflow module 5 employings of series connection, i.e. two IGBT elements 5.1 and 5.2; Output filter circuit 6 adopts filter capacitor C6 to distinguish transient state diode D3 in parallel until voltage output end Uu at input and output side.

See Fig. 5, in control loop, cpu control circuit 8 is single-chip computer control system, and the single-chip microcomputer model is AT89C2051.In the feedback unit 7, be provided with the sample circuit that C7, R7.1, R7.2 and R7.3 form, its input A6 connects major loop capacitor C 6 circuit end A6 (see figure 1)s; If feedback comparator T7, its input positive terminal accesses the sample circuit, and this place is the output voltage sampling; Input negative pole termination is regulated and is used potentiometer R7, and this place is feedback reference voltage; Feedback comparator output terminal N7 connects single-chip microcomputer 8 pins 16.The feedback comparator is sent signal into cpu control circuit 8, and CPU judges that the back determines the pulse of opening of adjusting IGBT to regulate the amplitude of boosting.

In the IGBT drive circuit 9, include optical coupling isolation circuit 9.1; Triode T9 (2N2222), the push-pull amplifier, the voltage stabilizing didoe D9 that form by Darlington transistor M9 (forming) by TIP122 and TIP127.And establish gate driving resistance R 9, the G utmost point of the IGBT element 4.1 in the drive circuit 9 output W9 of R9 and major loop is connected; The input N9 of IGBT drive circuit 9 is connected with the pin 12 of single-chip microcomputer 8.In like manner, the G utmost point of the IGBT element 4.2,5.1,5.2 in the output W9 of the pin of single-chip microcomputer 8 14,17,19 by other three IGBT drive circuits 9 and the major loop is connected, in order to control opening or closing of four groups of IGBT.

Be provided with overtemperature prote circuit 10.1 in the protective circuit 10, establish thermistor R in it ₁₀Be close to respectively on the shell radiator of four groups of IGBT, as the temperature detection of IGBT; Thermistor R ₁₀Jointing temp comparator T _10.1The input positive terminal, output is through N _10.1Connect the pin 6 of single-chip microcomputer 8.

Be provided with current foldback circuit 10.2 in the protective circuit 10, it can adopt commercially available special-purpose Drive Protecting Circuit, (such as: the EXB841 of Fuji), its a termination fast recovery diode D ₁₀And connect the C utmost point of four groups of IGBT elements of major loop respectively, its other end N through it _10.2Connect the pin 6 of single-chip microcomputer 8.The C utmost point and E utmost point on-state voltage drop by the IGBT element are judged over-current and-load (comprising the overcurrent that short circuit and overload produce).

See Fig. 3, display unit 11 following compositions: other establishes independent single-chip microcomputer 11.4, model AT89C2051.Establish respectively and connect input voltage sample circuit 11.1, AC-DC conversion 11.2, the V/f conversion that connects in turn; The output voltage sample circuit 11.1 of Lian Jieing, AC-DC conversion 11.2, V/f conversion in turn, its V/f conversion output connects the

8 and 9 of single-chip microcomputer 11.4 respectively.If display driver circuit 11.5 (adopting model SAAC064 integrated package), with its driving display 11.6 (adopting digital display tube LCD), display driver circuit 11.5 connects the

12 and 13 of single-chip microcomputer 11.4.Display unit 11 is a digital pulse signal with major loop input, the numerical value of output voltage and the analog signal conversion of waveform thus, and is input in the single-chip microcomputer 11.4 to show.See Fig. 4, above-mentioned voltage sample circuit 11.1 can adopt and contain capacitor C ₁₁And resistance R _11.1, R _11.2, R _11.3Circuit, input A1 and A6 connect major loop input A1 and output terminals A 6 respectively.AC-DC conversion 11.2 and V/f change-over circuit are custom circuit, no longer describe here.

See Fig. 2, open-minded when two-way boost copped wave module 4 (4.1 and 4.2), to inductance L 2 chargings, load this moment R is by capacitor C 6 power supplies by input voltage; When two-way boost copped wave module 4 disconnections, two-way afterflow module 5 (5.1 and 5.2) continues open-minded, and input voltage and inductance L 2 additions are jointly to capacitor C ₆Charging, output voltage is both electric energy stacks.Feedback unit 7 detects output voltage and send CPU control IGBT, increases voltage thus and realizes boosting voltage stabilizing.

Claims

1. digital low-voltage compensation arrangement is provided with voltage input end Ui, voltage output end U ₀, it is characterized in that: in major loop, behind the voltage input end Ui serial connection energy-storage units (2), parallel IGBT boost chopper module (4), series IGBT afterflow module (5) and output filter circuit (6) again are until voltage output end Uu; In control loop, if the feedback unit (7) that is connected with output filter circuit (6), connect cpu control circuit (8) then, the pin of circuit (8) is connected with two groups and above IGBT grid G in IGBT boost chopper module and the IGBT afterflow module respectively by IGBT drive circuit (9).

2. by the described compensation arrangement of claim 1, it is characterized in that establishing the protective circuit that comprises overtemperature prote and overcurrent protection (10) in order to protection IGBT.

3. by the described compensation arrangement of claim 1, it is characterized in that the input and output sampling switching circuit that display unit (11) is set and sets independent CPUs control circuit (11.4) and be complementary.

4. by the described compensation arrangement of claim 1, it is characterized in that being provided with in the feedback unit (7) at control loop the potentiometer R7 that regulates output voltage.

5. by the described compensation arrangement of claim 1, it is characterized in that between input Ui and energy-storage units (2) and connect by capacitor C ₁Or the circuit-formed input filter circuit of CL (1).

6. by the described compensation arrangement of claim 1, it is characterized in that at major loop input, output respectively and connect the anti-surge circuit (3) that constitutes by transient state diode D3.

7. by the described compensation arrangement of claim 1, it is characterized in that energy-storage units (2) is by the energy storage inductor L that adapts to high-frequency impulse ₂Or inductance L ₂Constitute with the absorption electric capacity of parallel connection.