CN204068710U - A kind of novel three port isolation type bipolar DC converters - Google Patents

Abstract

The utility model provides a kind of novel three port isolation type bipolar DC converters, comprises the power converter cells circuit of the three-phase windings accessing intermediate frequency transformer respectively; Power converter cells circuit comprises full bridge inverter, electric capacity of voltage regulation and reactor; The tie point of the power electronic device connected in the same way in full bridge inverter is connected with the two ends of Transformer Winding respectively; In full bridge inverter, the tie point of the power electronic device of Opposite direction connection is connected with the tie point of the same power electronic device be connected in the same way with electric capacity of voltage regulation by reactor successively, described tie point ground connection.Compared with prior art, the novel three port isolation type bipolar DC converters of the one that the utility model provides, structure is simple, can balanced bipolar direct current system voltage, possesses monopolar operation ability.

Description

A kind of novel three port isolation type bipolar DC converters

Technical field

The present invention relates to a kind of DC converter, be specifically related to a kind of novel three port isolation type bipolar DC converters.

Background technology

After the direct current tandem that the direct current that rectification exports by the DC distribution in DC power-supply system and batteries export becomes continual direct current to export bus, then tap is the load supplying branch road of various capacity, powers to the load after importing corresponding fuse or on-load switch into.

With traditional AC distribution net ratio, DC distribution net has the following advantages:

1.: the interchange link in transformation of electrical energy reduces, while reducing system element number, current transformer loss is also reduced; There is not eddy current loss and reactive power, reduce line loss;

2.: be convenient to distributed power source and be connected with load;

3.: improve the quality of power supply and power supply reliability;

4.: provide more economic illumination to select.

Existing DC distribution net comprises two-wire system, three-wire system (bipolar) and five-wire system; Wherein because bipolar DC system possesses monopolar operation ability, reduce circuit withstand voltage, be convenient to the advantages such as load access voltage selection and be subject to extensive concern.Total capacity of energy storing device in reduction system, raising power supply reliability will be contributed to by interconnected for multiple Bipolar DC power system; Therefore need to provide a kind of bipolar DC converter with multiterminal.

Summary of the invention

In order to meet the needs of prior art, the invention provides a kind of novel three port isolation type bipolar DC converters, described converter comprises the power converter cells circuit accessing intermediate frequency transformer three-phase windings respectively;

Described power converter cells circuit comprises full bridge inverter, electric capacity of voltage regulation and reactor; The tie point of the power electronic device connected in the same way in described full bridge inverter is connected with the two ends of Transformer Winding respectively; In described full bridge inverter, the tie point of the power electronic device of Opposite direction connection is connected with the tie point of the same power electronic device be connected in the same way with electric capacity of voltage regulation by reactor successively, described tie point ground connection.

Preferably, in described full bridge inverter, the tie point of the power electronic device of Opposite direction connection is connected by electric capacity; The capacity that described electric capacity is used between Bipolar DC power system collects and exchanges;

Preferably, in described reactor, electric capacity of voltage regulation and described full bridge inverter, the adjacent power electronic device of tie point ground connection forms voltage balance circuit, for the output voltage of the described converter of equilibrium;

Preferably, in described full bridge inverter, the conducting duty ratio of the power electronic device of Opposite direction connection is identical;

Preferably, the carrier phase of the power electronic device connected in the same way in described full bridge inverter is identical; The carrier phase of the power electronic device of Opposite direction connection differs 180 °.

Compared with immediate prior art, excellent effect of the present invention is:

1, in technical solution of the present invention, do not need to arrange extra voltage balancer, ensured the electric voltage equalization of Bipolar DC power system by voltage balance circuit, make circuit structure simpler;

2, the invention provides a kind of novel three port isolation type bipolar DC converters, the input of converter and the current continuity of output can be ensured, be applicable to the occasion of relatively high power, and Bipolar DC power system monopolar operation can be realized;

3, three port isolation type bipolar DC converters proposed by the invention by realize switch element, DC capacitor share, effectively reduce component population in circuit, improve circuit power density.

Accompanying drawing explanation

Below in conjunction with accompanying drawing, the present invention is further described.

Fig. 1 is: two-way isolation three end transformer configuration figure;

Fig. 2 is: the element circuit figure of novel three port isolation type bipolar DC converters in the embodiment of the present invention;

Fig. 3 is: the signature waveform figure of element circuit shown in Fig. 2;

Fig. 4 is: novel three port isolation type bipolar DC transformer configuration figure in the embodiment of the present invention;

Fig. 5 is: DC converter equivalent circuit diagram during Transformer Winding star-like connection in the embodiment of the present invention;

Fig. 6 is: in the embodiment of the present invention, DC converter is equivalent to circuit diagram when Transformer Winding angle-style connects.

Embodiment

Be described below in detail embodiments of the invention, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has element that is identical or similar functions from start to finish.Be exemplary below by the embodiment be described with reference to the drawings, be intended to for explaining the present invention, and can not limitation of the present invention be interpreted as.

Fig. 1 shows a kind of two-way isolation three end transformer configuration figure, is applicable to monopolar D. C system, therefore for realizing three end Bipolar DC power systems, needs two converters as shown in Figure 1 to be carried out mirror image splicing composition; Needing to make to carry out power between Bipolar DC power system alternately by arranging balance of voltage device simultaneously, can cause like this:

1.: the quantity of electronic device described in converter all can roll up:

2.: each bipolar DC system arranges separately a voltage equalizer, at this moment voltage equalizer capacity will according to one pole side Capacity design.And in most cases, voltage equalizer will be operated in light duty;

3.: placed near POL and power supply point respectively by multiple voltage equalizer, then DC distribution network control system and structure can be made more complicated; And interconnected for realizing between multiple bipolar DC system, transformer configuration will be more complicated.

As 4 show a kind of DC converter adopting element circuit as shown in Figure 2 provided by the invention, overcome above-mentioned technical problem of the prior art;

Three power converter cells electricity access intermediate frequency transformer T respectively _rcorrespondence three windings;

Wherein, 1.: N _g1, N _g2and N _g3be respectively the number of turn of Transformer Winding;

2.: Z _{grid1_p}, Z _{grid2_p}and Z _{grid3_p}be converter connect the equiva lent impedance of external circuit positive terminal;

Z _{grid1_N}, Z _{grid2_N}and Z _{grid3_N}be converter connect the equiva lent impedance of external circuit negative pole end;

U _{grid1_p}, U _{grid2_p}and U _{grid3_p}be converter connect the equivalent voltage source of external circuit positive terminal;

U _{grid1_N}, U _{grid2_N}and U _{grid3_N}be converter connect the equivalent voltage source of external circuit negative pole end;

3.: L _{grid1_p}, L _{grid2_p}and L _{grid3_p}be the reactor be connected with Bipolar DC power system positive pole side;

L _{grid1_N}, L _{grid2_N}and L _{grid3_N}be the reactor be connected with Bipolar DC power system negative pole side.

As shown in Figure 2, power converter cells circuit comprises full bridge inverter, reactor L _{2_P}and L _{2_N}, electric capacity of voltage regulation C _{2_P}and C _{2_N}, electric capacity C _couple;

1.: full bridge inverter comprises power electronic device S ₁, S ₂, S ₃and S ₄;

2.: electric capacity C _couplebe connected to power electronic device S ₁and S ₂tie point and power electronic device S ₃and S ₄tie point between, collect for the capacity between Bipolar DC power system and exchange;

3.: reactor L _{2_N}with electric capacity of voltage regulation C _{2_N}be connected to power electronic device S successively ₄two ends; Reactor L _{2_P}with electric capacity of voltage regulation C _{2_P}be connected to power electronic device S successively ₃two ends;

4.: power electronic device S ₁and S ₂tie point access Transformer Winding one end, power electronic device S ₃and S ₄tie point access Transformer Winding the other end; Power electronic device S ₃and S ₄tie point ground connection;

5.: power electronic device S ₃and S ₄, reactor L _{2_P}and L _{2_N}, electric capacity C _coupleform voltage balance circuit, for the output voltage of equalizing transform device.

Fig. 3 shows the signature waveform figure of element circuit, power electronic device S in the present embodiment ₁and S ₃conducting duty ratio identical, power electronic device S ₂and S ₄conducting duty ratio identical; Power electronic device S ₁and S ₂carrier phase identical, power electronic device S ₃and S ₄carrier phase identical, the two difference 180 °;

Element circuit is substituted with pulsafeeder, ignores static exciter inductance, and transformer leakage inductance is converted primary side, DC converter equivalent circuit diagram when can obtain that Transformer Winding is star-like to be connected with angle-style respectively, as illustrated in Figures 5 and 6;

Wherein, U' _g2and U' _g3to be respectively shown in Fig. 4 two, three-winding voltage converts magnitude of voltage corresponding to first side winding, U _g1for the magnitude of voltage of first side winding, L' _g2and L' _g3be respectively show transformer two, three-winding inductance converts inductance value corresponding to first side winding;

By adjustment U _g1, U' _g2and U' _g3phase angle difference can regulating system active power flow between any two; As supposed U _g1advanced U' _g2electrical degree α, ignores the impact of high order voltage harmonic beyond first-harmonic, is approximately to port 2 transmitting active power P by port one:

$P=\frac{U_{g1}*{U_{g1}}^{\′}\sin \mathrm{\α}}{{\mathrm{wL}}_{12}}$

Wherein, w is fundamental frequency; Power delivery between port one, 2 can be regulated by regulating α value.In like manner for other port, above-mentioned principle is applicable equally.

Finally should be noted that: described embodiment is only some embodiments of the present application, instead of whole embodiments.Based on the embodiment in the application, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the application's protection.

Claims (4)

1. novel three port isolation type bipolar DC converters, is characterized in that, described converter comprises the power converter cells circuit accessing intermediate frequency transformer three-phase windings respectively;

Described power converter cells circuit comprises full bridge inverter, electric capacity of voltage regulation and reactor; The tie point of the power electronic device connected in the same way in described full bridge inverter is connected with the two ends of Transformer Winding respectively; In described full bridge inverter, the tie point of the power electronic device of Opposite direction connection is connected with the tie point of the same power electronic device be connected in the same way with electric capacity of voltage regulation by reactor successively, described tie point ground connection;

In described full bridge inverter, the tie point of the power electronic device of Opposite direction connection is connected by electric capacity; The capacity that described electric capacity is used between Bipolar DC power system collects and exchanges.

2. a kind of novel three port isolation type bipolar DC converters as claimed in claim 1, it is characterized in that, in described reactor, electric capacity of voltage regulation and described full bridge inverter, the adjacent power electronic device of tie point ground connection forms voltage balance circuit, for the output voltage of the described converter of equilibrium.

3. a kind of novel three port isolation type bipolar DC converters as claimed in claim 1, it is characterized in that, in described full bridge inverter, the conducting duty ratio of the power electronic device of Opposite direction connection is identical.

4. a kind of novel three port isolation type bipolar DC converters as claimed in claim 1, it is characterized in that, the carrier phase of the power electronic device connected in the same way in described full bridge inverter is identical; The carrier phase of the power electronic device of Opposite direction connection differs 180 °.