FR2820562A1 - AC/DC electrical energy conversion circuit uses a group of series and/or parallel connected transformers with controlled switched primary and rectified secondary circuits - Google Patents

Abstract

The primary circuit (1) includes a current generator which feeds the input terminals (2,3) and the secondary circuit (4) includes a voltage generator connected in parallel with the output terminals (5,6). Alternatively the primary circuit (1) includes a current generator connected in parallel with the input terminals (2,3) and the secondary circuit (4) includes a current generator connected to the output terminals (5,6). Electric energy conversion circuit comprising: (a) N transformers each with primary (PN) and secondary (SN) windings; (b) a primary circuit (1) connected to input terminals (2,3) to which the transformer primary (PN) terminals are connected; (c) a secondary circuit (4) connected to the output terminals (5,6) to which the transformer secondary (SN) terminals are connected. Each primary circuit (1) and secondary circuit (4) of the converter includes a group of switches (IN) (uni-directional, bi-directional, diodes, IGBT, thyristors, triacs, field effect or bipolar transistors, contactors, contacts, or other types) connected to the N primary and secondary windings. A controller (7) controls the switches (IN) of at least one of the primary or secondary switches. The switches (IN) are connected so that they can connect the primary or secondary windings in series or parallel via the controller (7).

Description

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The invention relates to an electronic circuit making it possible to make a series and / or parallel connection of generators.

Said circuit makes it possible in particular to vary the output voltage while maintaining a constant power.

It has the advantage of being simple to produce while tolerating simple breakdowns.

The circuit according to the invention comprises two conductors between which N generators are connected in parallel, the two conductors each comprising in series N + 1 switches situated between the connections of the generators, the two conductors being connected at each of their ends.

Said circuit is characterized in that said switches are associated with closing and opening means so that the generators are connected together in series and / or in parallel thus varying the output voltage of the circuit.

Depending on the applications sought, the generators can be transformers, inductors, capacitors, etc. and the switches can be diodes, insulated gate bipolar transistors (IGBT), thyristors, triacs, field effect transistors, bipolar transistors, contactors, contacts, blockable gate thyristors (GTO), IGCT, MOS etc.

In one embodiment, the means for closing and opening said circuit of the switches are inverters so that the phase shift of the inverters makes it possible to associate the N generators in series or in parallel.

In a variant, the generators are transformers each comprising a primary winding and a secondary winding.

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In a second variant, the N transformers are connected so that when their primary windings are in series, their secondary windings are in parallel, and vice versa.

- la figure 4 représente une autre variante de l'invention. Other objects and advantages will appear during the following description, with reference to the appended drawings, given by way of nonlimiting examples, in which: - Figure 1 represents a diagram representing a circuit according to the invention; - Figure 2 shows a diagram of an embodiment of a circuit according to the invention; - Figure 3 shows a diagram of a variant of the embodiment shown in Figure 2;

- Figure 4 shows another variant of the invention.

With reference to FIG. 1, the electronic circuit comprises two conductors 1, 2 between which N generators 3 are connected in parallel, N being an integer.

The two conductors 1,2 each comprise in series N + 1 switches 4 located between the connections of the generators 3.

The two conductors 1, 2 are connected together at each of their ends.

Said switches 4 are associated with closing and opening means so that the generators 3 are connected together in series and / or in parallel.

Depending on the number of generators 3 connected in series and / or in parallel, the output voltage Vs of the circuit will vary within a voltage range depending on the number of generators 3.

The generators 3 can be voltage or current generators, for example they are transformers, inductors, capacitors, or the like.

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The switches 4 can be diodes, IGBTs, thyristors, triacs, field effect transistors, bipolar transistors, contactors, contacts, GTO, IGCT, MOS, or the like.

In the embodiments shown in Figures 2 and 3, the generators 3 are transformers.

The electronic circuit shown comprises N = four transformers 3.

The transformers 3 each include a primary winding 6 and a secondary winding 7.

In the following description, the term “primary circuit 8” designates the circuit comprising the primary windings 6, and “secondary circuit 9” denotes the circuit comprising the secondary windings 7.

The embodiment shown in Figure 2 is now described in detail.

The secondary circuit 9 comprises two conductors 1,2 between which the four secondary windings 7 of the generators 3 are connected in parallel.

The two conductors 1,2 each have in series N + 1 = five switches 4 located between the connections of the secondary windings 7 of the generators 3.

The switches 4 used are diodes.

The two conductors 1,2 are also connected to a winding 16 and a capacity 17 connected in series. These two elements form the circuit output filter.

The primary circuit 8 is now described in detail.

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 The means for closing and opening the switches 4 of the primary circuit are inverter circuits 5. It is in fact the controlled switches of the inverters 5 which cause the spontaneous switches of the diodes 4.

In the embodiment shown, each primary winding 6 of a transformer 3 is connected to an inverter circuit 5, said inverter circuit supplying the associated transformer 3.

In conventional manner, the inverter circuits 5 used are single-phase inverters comprising control signal generators 11, switches 10, and a capacitor 12.

In the embodiment shown in FIG. 2, the four inverter circuits 5 are identical. For clarity, the references are only indicated on the first inverter circuit 5 of FIG. 2.

Each end of a primary winding 6 of a transformer 3 is connected to two conductors, each comprising a switch 10. Each switch 10 is connected to a generator of control signals 11. Each switch 10 connected to one end of said primary winding 6 is also connected to the switch 10 connected to the other end of said winding 6 by a conductor 14.

These two conductors 14 are mounted in parallel with the capacitor 12 and in series with on the one hand a winding 15 and the voltage generator 13 input of the circuit and on the other hand the following inverter circuit 5.

The inverter circuits 5 are therefore connected in series to the input voltage generator 13.

All of the capacitors 12 and the winding 15 constitute an input filter of the electronic circuit.

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 FIG. 3 describes a variant of the embodiment of FIG. 2. In these figures, the same references designate the same components.

In this variant, the secondary circuit 9 is identical to the secondary circuit described in the previous embodiment. Only the primary circuit 8 is different, it is described below.

The primary circuit 8 comprises two conductors 18, 19 between which are connected in parallel N = four primary windings 6 of the generators 3.

The two conductors 18, 19 each comprise in series N + 1 = five switches 4 located between the connections of the primary windings 6 of the generators 3. These switches 4 are the means for closing and opening the switches 4 of the secondary circuit 9.

These switches 4 can be diodes, IGBTs, thyristors, triacs, field effect transistors, bipolar transistors, contactors, contacts, GTO, IGCT, MOS, or the like.

The two conductors 18, 19 are also mounted in parallel with a capacitor 12 and in series with a winding 15 and the voltage generator 13.

The operation of the entire circuit shown in Figure 2 is now described in detail.

The phase shift of each of the inverter circuits 5 will make it possible to associate the secondary windings 7 of the transformers 3 in series or in parallel.

The assembly is such that when all the inverter circuits 5 are in phase, the secondary windings 7 of the transformers 3 are then in parallel.

When the inverter circuits 5 are in phase opposition two by two, the secondary windings 7 of the transformers 3 are then in series.

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 By adjusting the phase between these two extreme values, it is thus possible to adjust the coefficient VsNe.

In this embodiment, with N inverter circuits in series, a dynamic range of N of the electronic circuit is obtained.

This electronic circuit has the advantage of being tolerant of a single fault: whatever the fault mode of a switch, of a generator 11 or 3, it is possible to operate in degraded mode.

The faulty floor is then isolated by applying an appropriate command to the switches. This has the consequence of limiting the capacities of the entire circuit (the range of variation of the voltages is reduced) without the latter ceasing to function.

In a variant shown in Figure 3 of this embodiment, the secondary windings 7 of the transformers 3 are wired to be connected in series when the primary windings 6 are in parallel, and vice versa.

2 sortie entre Ve/N et N. Ve. La dynamique du circuit électronique est alors de N2. So that, if we consider that the transformers 3 have transformation ratios equal to 1, it is possible to vary the voltage of

2 output between Ve / N and N. Ve. The dynamics of the electronic circuit is then N2.

Indeed, when the primary windings 6 are in series, the secondary windings 7 are in parallel and their output voltage is equal to the output voltage of the primary windings 6, namely, Ve / N.

When the primary windings 6 are in parallel, their input voltage is Ve, and the secondary windings 7 are in series so that their output voltage is equal to N. Ve.

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This arrangement has the advantage of being able to be used with a highly variable input voltage (for example from 100 Volts to 1600 Volts) and of regulating the output voltage to a fixed value.

The higher the number N of generators, the more the range of variation of the voltages is increased.

It also makes it possible to guarantee the balancing of the generator voltages, since when the primary windings are in parallel, the secondary windings are in series and vice versa.

The electronic circuit has other advantages.

In particular, the apparent frequency at the output and at the input of said circuit is higher than the frequencies of the generators used, so that a filter used at the output and at the input of the circuit will be of reduced size compared to a conventional circuit.

In FIGS. 2 and 3, the filter leaving the circuit is represented by the winding 16 and the capacitor 17, while the filter entering the circuit is represented by the winding 15 and the capacitor (s) 12.

Furthermore, the current flowing continuously in the circuit according to the invention, the filters at the input and output of the circuit will be less stressed than in a conventional circuit having a high pulsed current.

The electronic circuit according to the invention has a wide field of application in electronics. It can for example be used auto configurator parallel series.

The invention is not limited to the embodiments described, and in particular to the value of N used. The latter can be very variable.

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On peut notamment envisager toutes les associations en parallèle et/ou en série des générateurs 3 sans sortir du cadre de l'invention. La totalité ou une partie des éléments du circuit électronique peut par ailleurs être pilotée par ordinateur pour obtenir l'association voulue de générateurs 3.

One can in particular envisage all the associations in parallel and / or in series of the generators 3 without departing from the scope of the invention. All or part of the elements of the electronic circuit can also be controlled by computer to obtain the desired combination of generators 3.

We will now describe two particular applications of the invention.

In a first application of the electronic circuit according to the invention, the latter replaces the energy converter arranged in a rail vehicle, supplied with a direct voltage of 1500V or 3000V, said converter being able to transform this direct voltage into a proper voltage to supply electrical components on board this vehicle.

By using an electronic circuit according to the invention in place of the known energy converters, it is possible to eliminate the input filter.

Indeed, in known embodiments, the UIC 550 standard (International Union of Railways) requires the use of a heavy and bulky input filter consisting of a condenser and an inductor.

Thanks to the electronic circuit according to the invention, it is possible to remove the bulky filter above, while respecting the above standard.

The input generator then becomes a current generator.

The regulation of the switch control commands regulates a constant current for all frequencies above 50 Hz, thus creating a high input impedance.

Below 30Hz, the current setpoint is adapted to adjust the output voltage.

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FIG. 4 illustrates another application of the electronic circuit according to the invention. In this application, the switches are diodes di, d2, d3, d4, etc. and the generators are transformers comprising a primary P1, P2 and a secondary Si, 82. This electronic circuit is supplied by a voltage source constant EV input.

The circuit also includes a filtering inductor L and a capacitor C.

This circuit is suitable for associating the primary circuits Pi, P2 of the transformers in series or in parallel to vary the output voltage Vs + and Vs-at constant power.

Claims (9)

 CLAIMS 1. Electronic circuit comprising two conductors (1, 2) between which N generators (3) are connected in parallel, the two conductors (1,2) each comprising in series N + 1 switches (4) located between the connections of the generators (3), the two conductors (1,2) being interconnected at each of their ends, characterized in that said switches (4) are associated with closing and opening means so that the generators are connected between them in series and / or in parallel thus varying the output voltage (Vs) of the circuit. 2. Electronic circuit according to claim 1, characterized in that the generators (3) are voltage or current generators. 3. Electronic circuit according to claims 1 or 2, characterized in that the switches (4) are diodes, or IGBTs, or thyristors, or triacs, or field effect transistors, or bipolar transistors, or contactors, or contacts, or GTO, or IGCT, or MOS. 4. Electronic circuit according to claims 1 to 3, characterized in that the means for closing and opening the switches (4) are inverters (5) so that the phase shift of the inverters makes it possible to associate the N generators (3 ) in series and / or in parallel. 5. Electronic circuit according to claim 4, characterized in that the circuit comprises N inverters (5). 6. Electronic circuit according to one of claims 1 to 5, characterized in that the generators (3) are transformers (3) each comprising a primary winding (6) and a secondary winding (7). 7. Electronic circuit according to claim 6, characterized in that the N transformers (3) are connected so that when the windings <Desc / Clms Page number 11>  primary (6) are in series, the secondary windings (7) are in parallel, and vice versa. 8. Application of the electronic circuit according to one of the claims 1 to 7, as an energy converter arranged in a railway vehicle, supplied with a direct voltage of 1500V or 3000V, said converter being capable of transforming this direct voltage into a voltage suitable for supplying electrical members on board this vehicle, characterized in that said electrical converter does not have an input filter. 9. Application of the electronic circuit according to one of the claims 1 to 7, in which the switches are diodes and the generators are transformers, this electronic circuit being supplied by a constant input voltage source, this circuit comprising means for associating the primary circuits of the transformers in series or in parallel to vary the output voltage, at constant power.