CN201118461Y

CN201118461Y - A dynamic voltage balance circuit for five-level commutator

Info

Publication number: CN201118461Y
Application number: CNU2007200285887U
Authority: CN
Inventors: 何洪臣; 李瑞来; 杜秀虹; 郝延磊; 赵强
Original assignee: Shandong Xinfeng Photoelectric Science & Technology Development Co Ltd
Current assignee: Shandong Xinfeng Photoelectric Science & Technology Development Co Ltd
Priority date: 2007-10-10
Filing date: 2007-10-10
Publication date: 2008-09-17
Anticipated expiration: 2017-10-10

Abstract

The utility model discloses a dynamic equalization circuit for a five-level rectifier and is composed of a three-phase bridge rectifier circuit, three uniform voltage detection control circuits and a main switch loop; the main switch loop has six clamping diodes and four serially connected filter capacitors; each voltage detection control circuit has a positive sampling point, a neutral sampling point and a negative sampling point to sample two adjacent capacitors respectively. All the circuits from the entire dynamic equalization circuit of the five-level rectifier. The detection control circuit of the utility model detects the voltage on each capacitor rather than the voltage between the positive and negative buses so as to greatly reduce the voltage value of the detection circuit and improve the accuracy of voltage detection. The highest turn-off voltage that each power switching device bears is only half of the positive and negative bus voltage, so voltage withstand requirements of the power switching devices are reduced. Compared with the traditional resistance voltage sharing way, the inductance voltage sharing greatly reduces the energy consumption in the process of voltage sharing and improves the rectification characteristics of the device.

Description

A kind of dynamic voltage-balancing of five level rectifiers

Technical field

The utility model relates to a kind of multi-level rectifying pressure-equalizing device, belongs to electric and electronic technical field.

Background technology

Multi-level rectifier is all pressed three level of mode based on resistance in the market, the rectifier of five level and more level numbers is actually rare, study carefully its main cause, be that all pressures problem, especially the dynamic voltage balancing problem of multi-level rectifier solves relatively difficulty technically.Guarantee the multi-level rectifier operate as normal, must guarantee the electric voltage equalization between each level clamping point.Otherwise whole system is with cisco unity malfunction, and each main power device will bear too high voltages and damage.

Summary of the invention

The utility model provides a kind of equalizer circuit for solving the dynamic voltage balancing problem of five level rectifiers, detects each clamped point level of level rectifier in real time, in time adjusts voltage deviation, improves the stability of system.

The utility model circuit is made up of three-phase bridge rectifier circuit 1, three identical voltage detecting and controling

circuits

2,3,4 and main switch loop 5 as shown in Figure 1; Filtering capacitor C1, C2, C3, C4 that six clamping diode D1, D2, D3, D4, D5, D6 and four series connection are arranged in the main switch loop 5; Each voltage detecting and controling circuit just having, in, negative three sampled points, respectively to two neighboring capacitors samplings; Wherein:

The annexation of each components and parts is in the main switch loop 5: the anode of filtering capacitor C1 connects positive bus-bar A+, and the negative terminal of filtering capacitor C4 connects negative busbar A-; 1. diode D1, D2 and filtering capacitor C1, C2 tie point form clamped point; 2. diode D3, D4 and filtering capacitor C2, C3 interface form clamped point; 3. diode D5, D6 and filtering capacitor C3, C4 form clamped point;

The annexation in voltage detecting and controling circuit 2-4 and main switch loop 5 is: the positive termination positive bus-bar A+ of voltage detecting and controling circuit 2, middle termination clamped point 1., 2. negative terminal connects clamped point; The positive termination clamped point of voltage detecting and controling circuit 3 1., middle termination clamped point 2., 3. negative terminal connects clamped point; The positive termination clamped point of voltage detecting and controling circuit 4 2., middle termination clamped point 3., negative terminal meets negative busbar A-.Three topological circuits are arranged in the main switch loop, and three topological circuits comprise three inductor L1, L2, L3 and six device for power switching V1, V2, V3, V4, V5, V6; Wherein device for power switching V1, V2 the series connection, the series connection contact meet inductor L1, another termination clamped point of inductor L1 1., the collector electrode of device for power switching V1 meets positive bus-bar A+, 2. the emitter of device for power switching V2 connects clamped point; Device for power switching V3, V4 the series connection, the series connection contact meet inductor L2, another termination clamped point of inductor L2 2., 1. the collector electrode of device for power switching V3 connects clamped point, 3. the emitter of device for power switching V2 connects clamped point; Device for power switching V5, V6 the series connection, the series connection contact meet inductor L3, another termination clamped point of inductor L3 3., 2. the collector electrode of device for power switching V5 connects clamped point, the emitter of device for power switching V6 meets negative busbar A-.The control signal of topological circuit is provided by voltage detecting and controling circuit.

Foregoing circuit has constituted the dynamic voltage-balancing of whole five level rectifiers.

Operation principle of the present utility model is as follows: in the course of the work, adjacent arbitrarily two uneven the pressure occur in four capacitors, and corresponding voltage detecting and controling circuit just can detect the uneven signal of pressing, and provides control signal.The primary power switch device of the capacitor correspondence that voltage is high is open-minded, capacitor charges to reactor, condenser voltage reduces, and control signal is turn-offed, and corresponding device for power switching turn-offs, because reactor energy storage, electric current can not suddenly change, and this capacitor charging is given in the fly-wheel diode conducting in the primary power switch device on the lower capacitor of voltage, condenser voltage raises, and the voltage of two capacitors is reached unanimity.

Advantage of the present utility model is:

1, three voltage detecting and controling circuits detect is voltage on each electric capacity rather than the voltage between positive and negative busbar, greatly reduces the voltage value of testing circuit, has improved the accuracy of voltage detecting.

2, the highest shutoff voltage that bears of each device for power switching has reduced the requirement of withstand voltage of device for power switching only for positive and negative busbar voltage half.With traditional resistance all the pressure mode compare, inductor balancing greatly reduces the energy consumption in the pressure equalizing, has improved the rectification characteristic of this device.

3, can detect each condenser voltage in real time and also can in time adjust voltage deviation, guarantee the stable operation of five level rectifiers.

Description of drawings

Fig. 1 is the dynamic voltage-balancing figure of five level rectifiers.

Among the figure: three clamped points that 1., 2., 3. are main topological circuit;

1 is five level three-phase bridge rectifier circuits, 2～4th, and voltage detecting and controling circuit, the 5th, main switch circuit;

V1-V6 is a primary power switch device, and L1～L3 is an inductor, and C1-C4 is a capacitor;

A+, the A-, 0 that detect on the control circuit are respectively positive and negative, the intermediate point of rectification bus.

Embodiment

As shown in Figure 1, the utility model is by three-phase bridge rectifier circuit 1, three identical voltage detecting and controling

circuits

2,3,4 and main switch loop 5 form, six clamping diode D1 are arranged in the main switch loop 5, D2, D3, D4, D5, the filtering capacitor C1 of D6 and four series connection, C2, C3, C4, foregoing circuit has constituted the dynamic voltage-balancing of whole five level rectifiers, each voltage detecting and controling circuit just has, in, negative three sampled points, respectively to two neighboring capacitors samplings, the annexation in the annexation of each components and parts and voltage detecting and controling circuit 2-4 and main switch loop 5 is not described in detail in this as described in the technical scheme in the main switch loop 5.In conjunction with Fig. 1 operation principle of the present utility model is described once more below:

Require both end voltage Uc1, Uc2, Uc3, the Uc4 of capacitor C1, C2, C3, C4 all balanced during operate as normal.

When 1, the uneven pressure occurring, two kinds of situations are arranged as if two condenser voltages of C1, C2

(1) as if Uc1＞Uc2, then Dui Ying voltage detecting and controling circuit 2 provides control signal, the conducting of device for power switching V1 elder generation, and capacitor C1 gives inductance L 1 charging, inductance L 1 energy storage, C1 voltage descends.The V1 blocking interval, because inductance L 1 electric current can not suddenly change, inductance L 1 releases energy, and by the diode continuousing flow of device for power switching V2 inside, gives capacitor C2 charging, capacitor C2 voltage rises.Last capacitor C1, C2 both end voltage reach all presses.

(2) as if Uc1＜Uc2, then Dui Ying voltage detecting and controling circuit 2 provides control signal, the conducting of device for power switching V2 elder generation, and capacitor C2 gives inductance L 1 charging, inductance L 1 energy storage, capacitor C2 voltage descends; Device for power switching V2 blocking interval, because inductance L 1 electric current can not suddenly change, inductance L 1 releases energy, diode continuousing flow by device for power switching V1 inside, give capacitor C1 charging, capacitor C1 voltage rises, and last capacitor C1 and C2 both end voltage reach all presses.

2, as if capacitor C3, the uneven pressure of C4 voltage, its pressure equalizing is identical with the pressure equalizing of capacitor C1, C2.

3, voltage is uneven presses if capacitor C2 and C3 occur, voltage detecting and controling circuit 3 provides control signal, and device for power switching V3 or V4 conducting give inductance L 2 chargings, diode through device for power switching V3 or V4 inside carries out afterflow, comes the balance voltage of two brachium pontis up and down.

Claims

1, a kind of dynamic voltage-balancing of five level rectifiers is characterized in that, it is made up of three-phase bridge rectifier circuit (1), three identical voltage detecting and controling circuits (2-4) and main switch loop (5); The filtering capacitor (C1-C4) that six clamping diodes (D1-D6) and four series connection are arranged in the main switch loop (5); Each voltage detecting and controling circuit just having, in, negative three sampled points; Wherein:

The annexation of each components and parts is in the main switch loop (5): the anode of first filtering capacitor (C1) connects positive bus-bar (A+), and the negative terminal of the 4th filtering capacitor (C4) connects negative busbar (A-); First diode (D1), second diode (D2) and first filtering capacitor (C1), second filtering capacitor (C2) tie point form clamped point (1.); The 3rd diode (D3), the 4th diode (D4) and second filtering capacitor (C2), the 3rd filtering capacitor (C3) interface form clamped point (2.); The 5th diode (D5), the 6th diode (D6) and the 3rd filtering capacitor (C3), the 4th filtering capacitor (C4) form clamped point (3.);

The annexation of voltage detecting and controling circuit (2-4) and main switch loop (5) is: the positive termination positive bus-bar (A+) of first voltage detecting and controling circuit (2), middle termination clamped point (1.), negative terminal connect clamped point (2.); The positive termination clamped point (1.) of second voltage detecting and controling circuit (3), middle termination clamped point (2.), negative terminal connect clamped point (3.); Positive termination clamped point (2.), middle termination clamped point (3.), negative terminal that tertiary voltage detects control circuit (4) connect negative busbar (A-); Three topological circuits are arranged in the main switch loop (5), and three topological circuits comprise three inductors (L1-L3) and six device for power switching (V1-V6); Wherein first device for power switching (V1) and second device for power switching (V2) series connection, the series connection contact connects first inductor (L1), another termination clamped point (1.) of first inductor (L1), the collector electrode of first device for power switching (V1) connects positive bus-bar (A+), and the emitter of second device for power switching (V2) connects clamped point (2.); The 3rd device for power switching (V3) and the 4th device for power switching (V4) series connection, the series connection contact connects second inductor (L2), another termination clamped point (2.) of second inductor (L2), the collector electrode of the 3rd device for power switching (V3) connects clamped point (1.), and the emitter of second device for power switching (V2) connects clamped point (3.); The 5th device for power switching V5 and the 6th device for power switching (V6) series connection, the series connection contact connects the 3rd inductor (L3), another termination clamped point (3.) of the 3rd inductor (L3), the collector electrode of the 5th device for power switching (V5) connects clamped point (2.), and the emitter of the 6th device for power switching (V6) connects negative busbar (A-).