ES2350972T3 - POWER CONVERTER. - Google Patents

Abstract

An electric power converter comprising: - N transformers comprising, each of them, a primary winding (PN) and a secondary winding (SN), - a primary circuit (1) connected or connected to two input terminals or terminals (2, 3), to which the primary windings (PN) of the transformers are connected, - a secondary circuit (4) connected to two output terminals (5, 6), to which the secondary windings (SN) of the transformers, such that the primary circuit (1) of the converter comprises a set of switching means (IN, I'N, IN, 1, IN, 2) connected to the N primary windings (PN), characterized in that comprises a set of switching means connected to the N secondary windings (SN), as well as control means (7) of the switching means (IN, I 'N, IN, 1, IN, 2) of at least one of the primary (1) or secondary (4) circuits, so that the switching means (I N, I 'N, IN, 1, IN, 2) are connected in such a way that the N primary windings (PN) can be associated in series and / or in parallel with the N secondary windings (SN), respectively in parallel and / or in series using the control means (7).

Description

The invention relates to an electric power converter that associates in series and / or parallel a plurality of transformers.

Converters are known that associate transformers in series or in parallel. 5

Thus, US 4,339,704 and US 3,419,786 describe a converter comprising a primary winding and several secondary windings. The converter is powered by an alternating voltage. The secondary windings are connected in parallel to two conductors, so that each conductor has diodes 10 connected in series. In this way, the two conductors are connected or connected to each other, between their respective diodes, by a secondary winding.

The converter described in US 3,419,786 comprises, in each conductor, N + 1 diodes for N 15 secondary windings. It also includes N switches connected in series with each secondary winding.

The converter described in US 4,339,704 comprises, in each conductor, N + 2 diodes connected in series, such that two diodes are arranged between the connections of 20 successive secondary windings. N  1 switches connect the two conductors between two diodes successively connected in series.

These two converters allow the output voltage to be varied by an N value, by associating the secondary windings in series or in parallel. 25

These, however, have the disadvantage of needing the use of numerous switches and do not allow fault tolerance in the primary circuit. On the other hand, these converters cannot operate with a continuous voltage at the input, and the voltage variation band or range remains limited. 30

The converter described by Rajapandian Allanar and Ned Mohan in a June 6, 1999 publication entitled “Full-range ZVS DC-DC [DC direct current] converter with two full bridges for a high-power battery charge "(" Full Load Range ZVS Hybrid DC-DC converter with 35 two full bridges for high power battery charging "), is a hybrid electric power converter comprising two transformers T1 and T2 and

a set of switching means Ta +, Ta, Tb + and Tb. This converter corresponds to the preamble of claim 1.

But this converter cannot operate with a continuous voltage at the input and is only capable of supplying a continuous voltage at the output. 5

The invention aims to solve these problems by presenting a simple embodiment converter that needs a small number of switches, while allowing a range of voltage variation at the output to be equal or greater, tolerating simple faults. 10

In addition, the converter according to the invention can operate with a continuous or alternating input or output voltage.

For this purpose, a first object of the invention is an electric power converter comprising:

- N transformers comprising, each of them, a primary winding and a secondary winding,

- a primary circuit connected to or connected to two terminals or input terminals, to which the primary windings of the transformers are connected,

- a secondary circuit connected to two output terminals, to which the secondary windings of the transformers are connected,

such that the primary circuit of the converter comprises a set of switching means connected to the N primary windings,

the energy converters comprising a set of switching means connected to the N secondary windings, as well as control means of the switching means of at least one of the primary or secondary circuits, so that the switching means are connected of a such that the 30 N primary windings can be associated in series and / or in parallel with the N secondary windings, respectively in parallel and / or in series using the control means.

In a first variant, the primary circuit comprises a current generator that feeds the input terminals, and the secondary circuit 35 comprises a voltage generator connected in parallel with the output terminals.

In a second variant, the primary circuit comprises a voltage generator connected in parallel to the input terminals, and the secondary circuit comprises a current generator connected to the output terminals.

In one embodiment, each primary or secondary circuit may adopt one of the following two dual configurations:

- the first configuration comprises two electrical conductors connected in parallel between the input or output terminals, such that each conductor comprises at least N + 1 means of switching in series, the two conductors being connected or connected to each other, between their respective switching means, by a primary or secondary winding,

- the second configuration comprises N + 1 electrical conductors connected in parallel between the input or output terminals, 15 such that each conductor comprises at least two means of switching in series, the conductors being connected or connected to each other two to two , between their respective switching means, by a primary or secondary winding.

Another object of the invention is a control method 20 of a converter according to the invention, in which the primary circuit has the first configuration.

This method comprises the steps consisting of moving a switching scheme or pattern successively along the pairs of switching means of the primary circuit and, for each pair of switching means, eventually reversing the state of one of the means of switching the pair or, successively, the state of the two switching means of the pair.

A pair of switching means then corresponds to two switching means connected in front of or behind the same winding.

Other objects and advantages will become apparent in the course of the description that follows, with reference to the accompanying drawings, provided by way of non-limiting examples, in which:

- Figure 1 represents a diagram of an embodiment of a converter according to the invention;

- Figure 2 represents a scheme of a second embodiment of the invention;

- Figure 3 represents a variant of Figure 1;

- Figure 4 represents a third embodiment of the invention; 5

- Figure 5 represents a curve of the input voltage as a function of time, Figures 5a, 5b and 5c schematically represent the serial and / or parallel connections adopted by the windings of the transformers as a function of the voltage represented in the curve of Figure 5; 10

- Figures 6 and 7 illustrate two switching modes of a converter according to the invention.

Electric power converters according to the invention comprise:

- N transformers (PN, SN) comprising, each of 15, a primary winding PN and a secondary winding SN, N being an integer,

- a primary circuit 1, connected to two terminals or input terminals 2, 3, to which the primary windings PN of the transformers are connected, 20

- a secondary circuit 4, connected to two output terminals 5, 6, to which the secondary windings SN of the transformers are connected.

Each primary 1 and secondary circuit 4 comprises at least 2N + 2 switching means IN and I’N. 25

The converter also comprises control means 7 of the switching means IN and I'N of at least one of the primary or secondary circuits, so that the switching means are connected in such a way that the N primary or secondary windings in series and / or in parallel using the control means.

The control means 7 can either govern only the switching means of the primary circuit 1 or the secondary circuit 4, or govern the switching means of the primary circuits 1 and secondary circuits 4. 35

The switching means IN and I’N allow to open and close the circuit to which they are connected.

These switching means can be unidirectional, or one-way, or bi-directional, or both-way switches, such as diodes, IGBT [insulated gate bipolar transistor - "Insulated Gate Bipolar Transistor"], thyristors, triac [current period alternate - “Triode for Alternating Current”], 5 field effect transistors, bipolar transistors, contact devices or contactors, GTO [door disconnect switch - “Gate Turn-Off Switch”], IGCT [Integrated Door Switched Thyristor - “Integrated Gate-Commutated Thyristor”], MOS [metal-oxide-semiconductor devices] or similar devices. 10

In a first variant, the primary circuit 1 comprises a current generator that feeds the input terminals 2, 3. This is, for example, a winding. The secondary circuit 4 then comprises a voltage generator connected in parallel to the output terminals 5, 6. This consists, for example, of a capacitor. fifteen

In a second variant, the primary circuit 1 comprises a voltage generator (for example, a capacitor) connected in parallel to the input terminals 2, 3, and the secondary circuit 4 comprises a current generator connected to the output terminals 5 , 6 (for example, a winding). twenty

The primary and secondary circuits 1 can adopt one of the two dual configurations described above.

The first configuration is described with reference to Figure 1, which represents a converter whose two primary and secondary circuits 4 adopt this first configuration. 25

In the example shown, the converter comprises N = 2 transformers.

The primary and secondary circuits 1 each comprise, respectively, two electrical conductors C1, C2 connected in parallel between the input terminals 2, 3 or output terminals 5, 6. 30

Each conductor C1, C2 comprises N + 1 switches in series IN and I’N, respectively.

The two conductors C1, C2 of the primary circuit are connected to each other, between their respective switches IN and I’N, by means of a primary winding PN. In this way, the 35 primary PN windings are connected in parallel between the two conductors C1, C2.

In the same way, the two conductors C1, C2 of the secondary circuit are connected to each other, between their respective switches IN and I'N, by a secondary winding SN, such that the secondary windings SN are connected in parallel between the two C1, C2 conductors. 5

In the embodiment represented in Figure 1, the IN and I’N switches of the secondary circuit are diodes. These diodes are connected, all of them, in the same direction.

The points represented in Figures 1 to 4, in the primary PN and secondary SN windings, symbolize the direction of the 10 windings.

Thus, in Figure 1, the windings P2, S2 are in the same direction, while the windings P1 and S1 are in inverse directions with respect to each other. This configuration allows obtaining a branch or parallel branch 15 of the windings of the secondary circuit when the windings of the primary circuit are in series, and vice versa.

For a converter of N transformers, when the primary and secondary circuits have the same configuration, one winding of every two of the secondary circuit is inverted with 20 relative to the corresponding windings of the primary circuit.

The second configuration, dual with respect to the first, is described with reference to Figure 2, which represents a converter whose primary circuit 1 has the first configuration, and whose secondary circuit 4 adopts this second configuration. 25

This duality between the two circuits implies the following priorities:

- when a switch is closed in the primary, the corresponding switch is opened in the secondary, and reciprocally;

- the voltage waveforms in the primary switches 30 become the waveforms of the currents in the secondary switches, and reciprocally;

- when the primary windings are connected in series, the secondary windings are connected in parallel, and reciprocally. 35

In the example shown in Figure 2, the converter comprises N = 2 transformers.

The primary circuit 1 is identical to that of Figure 1.

The secondary circuit 4 comprises N + 1 electrical conductors CN connected in parallel to the terminals or output terminals 5, 6 of the secondary circuit.

Each conductor CN of the secondary circuit comprises two switches IN, 1 and IN, 2 in series, such that the conductors CN are connected two to two to each other, between their respective switches, by a secondary winding SN.

In the embodiment shown in this Figure, switches IN, 1 and IN, 2 of the secondary circuit are diodes. 10

Since the configurations of the dual primary and secondary circuits 4 are dual with respect to each other, it is not necessary to reverse the direction of a winding of each two to obtain a parallel derivation of the secondary circuit windings when the primary circuit windings They are in series, and vice versa. fifteen

In this way, the points that symbolize the direction of the windings are all on the same side for the converter of Figure 2.

For an N transformer converter, when the primary and secondary circuits have dual configurations, all windings are in the same direction.

To obtain the reversibility of the converter, it would be necessary to associate switches in parallel in the diodes of the secondary circuit, so that the orders of these switches would be obtained by duality of the primary orders. Two-way switches IN, 1 and IN, 2 can also be used in both directions.

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

In this variant, the primary circuit 1 adopts the first configuration and the secondary circuit 4 adopts the second configuration.

The secondary circuit 4 is identical to that described by Figure 1, so that the same elements are indicated by the same references. 35

The two conductors C1, C2 of the secondary circuit are, on the other hand, connected to a winding 8 in series, and to a

capacity 9 in parallel.

Due to the presence of a winding 8, the secondary circuit has a current generator.

The primary circuit 1 is substantially identical to that described for Figure 1, such that the same references refer to the same components.

The two conductors C1, C2 of the primary circuit are connected in parallel with a capacity 13.

The capacity 13 is, in turn, connected in series with a winding 15 and a voltage generator 16. The latter is 10 connected between the input terminals 2, 3.

Due to the presence of capacity 13, the primary circuit has a voltage generator.

A third embodiment is described with reference to Figure 4. 15

In this embodiment, the primary and secondary circuits adopt the second configuration for a number of transformers N = 2. In this way, the direction of one of the secondary windings, here S2, is reversed with respect to the direction of the primary winding. corresponding P2 and the other 20 windings P1, S1.

Each switch IN, 1 and IN, 2 of the primary circuit is connected in parallel with a diode 17, in order to be able to operate bidirectionally.

The switches IN, 1 and IN, 2 of the secondary circuit are 25 diodes.

The primary circuit is powered by a voltage generator (VE). The secondary circuit is connected to a current generator (winding 18).

The winding 18 is mounted in series with the positive output terminal 30, and a capacity 19 is mounted in parallel between the output terminals 5, 6.

The operation of the different embodiments of the invention will be described below.

Ve is defined as the voltage between the input terminals 2 35, 3, and Vs as the voltage between the output terminals 5, 6.

It will be described below, with reference to Figure 1, the

operation of the converter in which the primary and secondary circuits are in the first configuration.

When the two windings P1 and P2 are in parallel, for example, when the switches I3 and I'1 of the primary circuit 1 are open and the other switches closed, if the input terminal 2 is 5 positive, the sides of the windings connected to terminal 2 they are equally positive. These sides correspond to the points in Figure 1.

As regards the structure of a transformer, the corresponding sides of the secondary windings S1 and S2, 10 symbolized by the points, are equally positive, which induces the circulation of current through the secondary circuit 4, the secondary windings being then serially.

Since the primary windings P1 and P2 are in parallel, the tension in each winding is equal to Ve. The voltage in each secondary winding is also, consequently, equal to Ve, if the transformation ratios are considered to be equal to 1 , so an output voltage Vs = 2 Ve.

When the windings P1 and P2 are in series, for example, when the switches I1, I'2 and I3 are closed and the other 20 open, the winding side P1 (marked by the point in the Figure) connected to the input terminal 2 (positive) is positive, and the side marked by the winding point P2 is negative. The tension in each winding P1, P2 is then equal to Ve / 2.

Consequently, the side marked by the winding point S1 is positive, while the side marked by the winding point S2 is negative, such that only the diodes I'1, I'2, I2, I3 are through or lead, and S1 and S2 are in parallel, the voltage in each winding S1, S2 being equal to Ve / 2.

In this way, the output voltage is Vs = Ve / 2. 30

Thus, for a converter comprising N transformers that have transformation ratios equal to 1, it is possible to vary the output voltage Vs between Ve / N and N · Ve. The dynamics of the electronic circuit is, then, N2.

It is possible, of course, that the primary windings 35 P1, P2 are in parallel when opening switches I1 and I’3 and closing the other switches. The voltages applied to the terminals of the

transformers are then inverted, which allows applying a necessary alternative operating voltage to the transformers.

With an alternative input voltage Ve, it is possible to obtain a continuous output voltage Vs by switching, at a convenient frequency, the switches of the primary circuit in relation to the frequency of variation of the alternative input voltage. It is then necessary that all primary circuit breakers be bidirectional.

This type of assembly has the advantage of being able to be used with a strongly variable input voltage (for example, 10 from 100 volts to 1,600 volts), and of regulating the output voltage to a fixed value.

The larger the number N of generators, the more the band or range of voltage variation increases.

The balancing of the transformer voltages is guaranteed, since, when the primary windings are in parallel, the secondary windings are in series, and vice versa.

Next, with reference to Figure 2, the operation of the converter will be described in which the primary and secondary circuits are respectively in the first and second configurations.

The fact that the two configurations are dual with respect to each other implies that, when the windings P1, P2 of the primary circuit are in parallel, the windings S1, S2 are in series, and vice versa. 25

Thus, when P1 and P2 are in parallel and their side marked with a point is positive, the corresponding side of S1 and S2 is equally positive, so that only diodes I1,1 and I3,2 are through or lead, and S1 and S2 are in series.

If P1 and P2 are in parallel but with an inverted polarity 30, then S1 and S2 are in series with an inverted polarity and only diodes I1,2 and I3,1 are passed through.

In the same way as for the preceding converter, it is possible to use a DC voltage generator at the input or, alternatively, to obtain a DC voltage at the output. 35

The operation of the circuit of Figure 3 will be described in the case of an alternating sinusoidal input voltage, such

as depicted in Figure 5.

The maximum Ve voltage is defined as Vmax, and V1 and V2 have input voltages that are substantially equal to approximately 1/3 Vmax and 2/3 Vmax, respectively.

The 5-input sinusoidal voltage curve can then be divided into several zones:

- a zone A corresponding to the voltage range 0  Ve  V1;

- a zone B corresponding to V1  Ve  V2;

- a zone C corresponding to V2  Ve  Vmax. 10

When Ve is placed in zone A, the input voltage is then quite small and can be supported by each transformer. The switches IN and I'N of the primary circuit are then, for example, switched in such a way that all primary windings PN are associated in parallel, so that the secondary windings SN are associated in series, such as It is represented in Figure 5a.

In this way, a small Ve voltage is applied to each winding PN, SN, and all SN windings are crossed by the same small current. twenty

When Ve is located in zone B, the input voltage is then higher and cannot be fully supported by each transformer. The switches IN and I'N of the primary circuit are then, for example, switched so that the primary windings PN are associated two by two in parallel, so that the secondary windings SN are associated in series. , two to two.

Thus, to each PN winding, SN a Ve / 2 voltage is applied, and all SN windings are crossed by a current whose intensity is divided by two. 30

When Ve is located in zone C, the input voltage is even higher and cannot be fully supported by each transformer. The switches IN and I'N of the primary circuit are then switched, for example, so that all primary windings PN are associated in series, thereby associating the secondary secondary windings SN in parallel, as depicted in Figure 5c.

In this way, a Ve / N voltage is applied to each PN, SN winding, and all SN windings are crossed by a current whose intensity has been divided by N.

For a circuit of N transformers, the possibilities of association of the primary windings in parallel and / or in series are much more numerous and allow regulating the output voltage depending on the use, for example, at a fixed value.

The embodiment depicted in Figure 4 will now be described in the following.

When the primary windings P1, P2 are in parallel, for example, when the switches I1,1, I3,1 and I2,2 are closed and the others open, the winding side P1 marked by a point is then positive, and the side of the winding P2 marked by a point is negative. In this way, the sides marked by a point of the secondary windings S1, S2 are then, respectively, positive and negative. This polarity implies that only diodes I1,1 and I3,2 are through or lead, and that the windings S1, S2 are in series.

Figures 7 and 8 represent conductors C1 and C2 of the primary circuit 1. Only the first seven 20 PN windings have been shown.

The sections of conductors C1 and C2 in thick lines illustrate switches IN, I’N closed, and the sections in thin lines, open switches IN, I’N.

A pair of switching means is defined as formed by two switching means connected behind or in front of the same winding.

Switching is carried out gradually by shifting a switching scheme or pattern, symbolized by a panel C, along the pairs of switching means and eventually reversing the state of one or both switching means contained in the table . In the case of two investments, these are made successively.

In this way, the command means successively govern each pair of switching means I1, I’1, followed by I2, 35 I’2,…, IN, I’N. At each stage, depending on the desired result, the switching means IN is inverted or not, after which the means of

I’N switching is reversed, or not.

This procedure allows, for example, to reverse the polarity of the primary circuit, or is used to reverse the polarity of the voltage at the terminals of each transformer.

The example represented in Figure 6 corresponds to the reversal of the polarity of the primary windings that are in a configuration, or all the PN primary windings are in series. The polarity inversion is obtained by inverting all the switches.

In the example depicted in Figure 7, the switching means is switched in such a way that it is passed from a configuration in which all switching means IN, I'N are in series, to a configuration in which the means Switching are parallel two to two.

- the switching of the switches is "almost smooth": the 15 dynamic losses are divided, in effect, by approximately four;

- a single switch switches at a time, which simplifies the implementation, so that there are, therefore, no problems associated with the simultaneous switching of semiconductors in series; twenty

- the apparent frequency seen from the primary is very high;

- the amplitude of the ripple in the terminals of the primary after the input impedance coil is very small, which allows the size of the input impedance coil to be reduced; 25

- the regulation of the input current is facilitated, since the response time of the regulation is very short.

On the other hand, when the current flows permanently through the circuit according to the invention, the input and output filters of the circuit will be less requested than in a conventional circuit 30 that has an important pulsating current.

The converter according to the invention has the advantage of being tolerant of a simple fault: whatever the failure mode of a transformer switch, it is possible to operate in degraded mode. 35

The faulty stage is then isolated by applying an appropriate order to the switches. This results in a

limiting the capabilities of the circuit as a whole (the range of voltage variation is reduced), without the latter ceasing to function.

On the other hand, a primary circuit that adopts the first configuration is well adapted to high voltages, since the 5 switches share the voltage between them. A secondary circuit that adopts the second configuration is well adapted to high output currents, since the switches share the output current.

The electronic circuit according to the invention has a vast domain of application in electronics.

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

In particular, all associations 15 in parallel and / or in series of the primary and / or secondary windings of the transformers can be contemplated without departing from the scope of the invention.

All or a part of the electronic circuit elements can be governed, on the other hand, by computer in order to obtain the desired transformer association. twenty

Two particular applications of the invention will be described below.

In a first application of the electronic circuit according to the invention, the latter replaces the power converter arranged in a railway vehicle, powered indifferently by a continuous voltage of 1,500 V or 3,000 V, or by an alternating voltage of 1,000 V or 1,500 V, so that said converter is capable of transforming this voltage into an appropriate voltage to power electrical organs installed on board this vehicle. 30

It is thus possible, using an electronic circuit according to the invention instead of the known power converters, to suppress the input filter.

Indeed, in known embodiments, the UIC 550 (International Railways Union - "Union Internationale des 35 Chemins de fer") standard imposes the use of a heavy and bulky inlet filter, consisting of a capacitor and an inductance.

Thanks to the electronic circuit according to the invention, it is possible to suppress the embarrassing previous filter while respecting the standards, which allows a considerable weight gain.

The input generator then becomes a current generator. 5

The switch control procedure regulates a constant current compatible with the UIC 550 standard, which creates a high input impedance.

Below 50 Hz, the current setpoint is adapted to adjust the output voltage. 10

Another application of the converter is its use as a converter in charge of guaranteeing the traction function of a railway vehicle, powered by an alternating voltage of 15,000 V or 25,000 V, so that the converter is suitable for transforming this voltage into a suitable voltage to supply electric organs 15 installed on board the vehicle. Said electric converter is then devoid of low frequency transformer (50 Hz or 16.7 Hz) and high input voltage.

The converter according to the invention can be used in numerous domains:

- in rail traction: the input transformer and its rectifier currently reach 13 tons, while a converter according to the invention does not reach more than 3 tons;

- medium power applications in different sector voltages: with a converter according to the invention, it is no longer necessary to modify the equipment; just change the command procedure;

- variable voltage and constant power supply feeds.

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Claims (14)

 1. An electric power converter comprising:   - N transformers comprising, each of them, a primary winding (PN) and a secondary winding (SN), - a primary circuit (1) connected to or connected to two terminals or input terminals (2, 3), to which the primary windings (PN) of the transformers are connected, - a secondary circuit (4) connected to two 10-output terminals (5, 6), to which the secondary windings (SN) of the transformers are connected, such that the primary circuit (1) of the converter comprises a set of switching means (IN, I'N, IN, 1, IN, 2) connected to the N primary windings (PN), characterized in that it comprises a set of switching means connected to the N secondary windings (SN), as well as control means (7) of the switching means (IN, I'N, IN, 1, IN, 2) of at least one of the circuits primary (1) or secondary (4), so that the switching means (IN, I'N, IN, 1, IN, 2) are connected in such a way that the N primary windings (PN) can be associated in series and / or in parallel with the N secondary windings (SN), respectively in parallel and / or in series using the control means (7).  2. A converter according to claim 1, characterized in that the primary circuit (1) comprises a current generator 25 that feeds the input terminals (2, 3), and the secondary circuit (4) comprises a voltage generator connected in parallel with the output terminals (5, 6).  3. A converter according to claim 1, characterized in that the primary circuit (1) comprises a voltage generator 30 connected in parallel to the input terminals (2, 3) and the secondary circuit (4) comprises a generator current connected to the output terminals (5, 6).  4. A converter according to one of claims 1 to 3, characterized in that each primary (1) or secondary (4) circuit 35 can adopt one of the following two dual configurations: - the first configuration comprises two conductors electrical (C1, C2) connected in parallel between the input (2, 3) or output (5, 6) terminals, so that each conductor (C1, C2) comprises at least N + 1 switching means (IN , I'N) in series, the two conductors (C1, C2) being connected or connected to each other, between their respective switching means (IN, I'N), by a primary winding (PN) or secondary winding (SN) , - the second configuration comprises N + 1 electrical conductors (CN) connected in parallel between the input (2, 3) or output (5, 6) terminals, such that each conductor (CN) comprises at least two means of switching (IN, 1, IN, 2) in series, the 10 conductors (CN) being connected or connected to each other two to two, between their respective switching means (IN, 1, IN, 2), by a primary winding ( PN) or secondary (SN).  5. A converter according to one of claims 3 and 4, characterized in that, when the primary (1) and secondary (4) circuits have the same configuration, one winding of every two (SN) of the secondary circuit is inverted with respect to the corresponding winding (PN) of the primary circuit, so that all other windings (PN, SN) are in the same direction.  A converter according to one of claims 3 20 and 4, characterized in that, when the primary (1) and secondary (4) circuits have different configurations, all windings (PN, SN) are in the same direction .  A converter according to one of claims 1 to 6, characterized in that the switching means (IN, I'N, IN, 1, IN, 2) of the secondary circuit (4) and / or of the primary circuit (1) they are unidirectional switches, or one way, or bidirectional, or both directions.  A converter according to one of claims 1 to 7, characterized in that the control means (7) governing the switching means (IN, I'N, IN, 1, IN, 2) of the primary circuit (1) and the secondary circuit (4) are governed switches, both in the primary and in the secondary.  9. A converter according to one of claims 3 to 8, characterized in that it comprises:   - a primary circuit (1) that adopts the first configuration, such that the two conductors (C1, C2) of the circuit primary are in parallel with a capacity (13);   - a winding (15) in series with the capacity (13);   - a voltage generator (16), connected between the input terminals (2, 3);   - a secondary circuit (4) that adopts the first configuration, whose two conductors (C1, C2) are in series with a winding (8) and in parallel with a capacity (9);   in such a way that the switching means (IN, I’N) of the secondary circuit are diodes.  10. A converter according to one of claims 3 to 10, characterized in that it comprises:   - a primary circuit (1) that adopts the second configuration, in which the switching means (IN, 1, IN, 2) are unidirectional switches in parallel, each of them, with a diode; fifteen   - a secondary circuit (4) that adopts the second configuration, in which the switching means (IN, 1, IN, 2) are diodes;   - a capacity (19) in parallel with the output terminals (5, 6); twenty   - a winding (18) in series with one of the output terminals (5, 6).  An application of the converter according to one of claims 1 to 10, as an energy converter arranged in a railway vehicle, powered by a continuous voltage of 1,500 V or 25,000 V, or by an alternating voltage of 1,000 V or 1,500 V, in such a way that said converter is capable of transforming this voltage into an appropriate voltage to power electrical organs installed on board this vehicle, characterized in that said electric converter is devoid of an input filter. 30  12. An application of the converter according to one of claims 1 to 10, as a converter responsible for guaranteeing the traction function of a railway vehicle, powered by an alternative voltage of 15,000 V or 25,000 V, such that said converter is suitable for transforming this voltage into a voltage 35 suitable for supplying electrical organs installed on board this vehicle, characterized in that said electrical converter is devoid of low frequency transformer and high input voltage.  13. A drive control method according to claim 4 or one of claims 5 to 9 when these are dependent on claim 4, in which the primary circuit 5 has the first configuration, such that a pair switching means correspond to two switching means connected before or after the same winding, characterized in that it comprises the steps consisting of moving a switching scheme or pattern successively along the pairs of switching means 10 of the primary circuit and, for each pair of switching means, optionally invert the state of one of the switching means of the pair or, successively, the state of the two switching means of the pair.