MXPA99001451A - Inverter for inputting sinusoidal currents into an alternating current network - Google Patents

Abstract

The invention relates to an inverter for inputting sinusoidal currents into an alternating current network. The invention seeks to improve resistance to short circuiting and to reduce the risk thereof. According to the invention, only one switching unit is used to generate a semi-oscillation of a sinusoidal oscillation. In order to generate a positive semi-oscillation of a sinusoidal oscillation, a second switching unit is used in addition to the one used to generate the negative component of a sinusoidal current. As a result, only one switch pertaining to a switching unit is clocked or actuated to generate a positive semi-oscillation. Another switch is clocked or actuated to generate a negative semi-oscillation of a sinusoidal current. The risk of a short circuit between both switches is thus reduced to the period occurring between switching from the positive to the negative or from the negative to the positive semi-oscillation.

Description

RECTIFIER FOR THE POWER SUPPLY OF SENOID CURRENTS TO AN ALTERNATE CURRENT NETWORK DESCRIPTION OF THE INVENTION The object of the invention is a rectifier for the supply of sinusoidal currents to a network of alternating current to an open network of power supply. Such rectifiers are almost exclusively used as a power commutator in the configuration of a rotary current bridge as shown in FIG. 13. Such a rectifier d current generates a direct current / voltage source a multistage alternating current with the phases. U, V and. By means of the antiparallel switch shown in FIG. 13, and the power switch Ti to T6 with corresponding diodes, quadruple operation is possible and with rectifier switching applicable on many sides. It is disadvantageous in such rectifier switching that in case of a short circuit of two switches, eg TI and T2, an extremely large energy flow occurs, which regularly leads to a total destruction of the rectifier and possibly to the start of a fire and as to the destruction of all connected parts. It is the task of the present invention to improve the resistance to short circuit and reduce the danger thereof This is achieved according to the present invention with a rectifier having the indicated characteristics and REF. : 29392 claim 1. Other advantageous embodiments and qualities are described in the dependent claims. The present invention is based on the knowledge that, for the generation of a half-oscillation of a sinusoidal oscillation, only a single switching unit is used for the generation of a positive semi-oscillation of a sinusoidal oscillation. d switching in addition to the one used for the generation of the negative part of the sinusoidal current. This has as a consequence that during the generation of a positive half-oscillation only one switch of a switching unit is activated and during the generation of a negative half-oscillation of a sinusoidal current another switch. The danger of a short circuit between both commutations is reduced with time during the change of semi-oscillation d positive to negative or from negative to positive- Also for the generation of a semi-oscillation of a sinusoidal oscillation only another unit d commutation, responsible, so that the units of commutation that are indicated as responsible for different semi-oscillations, can also be placed with each other. This improves the safety of the switchgear and also makes it considerably easier to install space. A particularly preferred embodiment of the invention is characterized in that the supplied DC voltage is divided into a first partial DC voltage into a second partial DC voltage. . With this, for example, the first partial DC voltage is used for the generation of the negative part of the network current, and the partial DC voltage for the generation of the negative network current. For example, the two partial voltages or continuous voltages are 660 volts, where the total continuous voltage is 1320 V. The parts used in the first switching unit must then only be able to work under the first partial DC voltage, so much so that the parts of the second switching unit must be able to work only with the second continuous DC voltage. Also for the inductivities, if necessary, the existing semi-conductive switching elements that are connected to the switching units, accordingly. Since then those parts should not be as strong as in the case of the known rectifier shown in Figure 13, they can save considerable costs. In other words, a double output power of the rectifier assembly resulted in the use of construction parts, which only have to work under a partial DC voltage. The invention is described in detail below with reference to embodiments shown in the drawings, where Figure 1 shows a switching with the basic principle of a switching unit to generate the positive part of the network current; Figure 2 a drawing of switching of the basic principle of a switching unit for the generation of the negative part of the network current; FIG. 3 a switching diagram of the basic principle for the generation of the current of a phase with the aid of switching operations according to FIG. 1 and FIG. 2; Figure 4 switching image of the basic principle for a joint switching of several switching units according to Fig 1 and 2 for the generation of three phase current U, V and W; Figure 5 Course of the current and time switching diagram for the control of the switch TI and T2 of the first and second switching unit; Figure 6: amplified switching image for the generation of single-phase current; Figure 7: switching image of the basic principle of a switching unit for the generation of the positive part of the network current with an additional tirristor connected intermediate; FIG. 8 shows the switching image of the basic principle of a switching unit for generation of the negative part of the network current with an additional linker connected intermediate; Figure 9 basic principle image for the generation of single-phase current with the help of the switches of Figures 7 and 8; Fig. 10 Current course and time switch diagram for the control of switch T and T of the switching according to Fig. 9; Figure 11 is a basic principle image of a first embodiment of a joint commutation of several switching units according to Figure 7 and for the generation of the three-phase current U, V and; FIG. 12 shows a basic principle of a second embodiment of a joint commutation of several switching units according to FIG. 7 and that for the generation of the three-phase current U, V and; Figure 13 basic principle switching image of a known rectifier. Figure 1 shows a transverse branch or a switching unit l for the generation of the positive fraction d the alternating current of the network from a continuous voltage. The switching unit consists of a power switch Ti, for example an IGBT (isolated gate bipolar trnasistor) or GT (gate turn off) and a Di diode, which is put in series in the DC connections. Between the switch TI and the diode DI there is an outlet Al in which by means of an inductance Ll the current is managed. Figure 2 shows in a basic principle a switching image of a switching unit 2 for the generation of the negative part of the alternating current with a power transistor T2 placed in series, a diode D2 and a current tap or handling A2 and a subsequently connected inductivity L2. Figure 3 shows the parallel switching of the switching units described in Figures 1 and 2, by means of another inductance L3 as coupling inductance.

Parallel to the composite switching of units 1 and 2, a capacitor C is present in the continuous voltage network. For the generation of a three-phase rotary current with the phases U, V, and W - as shown in Figure 4, the first and the second switching unit are commuted to each other - as shown in Figure 3. The Figure 5 shows a diagram in time of how the switches TI and T2 are connected, for example obtaining a sinusoidal current for phase U. During the positive half-wave of the sinusoidal current only the switch TI is connected and disconnected in a prescribed pulse course, during this phase the switch T2 is disconnected. By means of a pulse of the switch-off state of the switch Ti, an indented current is generated. During the generation of the negative half-wave of the sinusoidal current, the switch T is turned off only the switch T2 is switched on and off at the predetermined pulse and time distances, so that the negative half-wave of the sinusoidal current is generated. The indented curs of the current, as represented in FIG. 5, is produced by the current guide and the alternating effect of the transistor Ti and the diode Di or the transistor T2 and diode D2 between them. In the area of maximum current of a sine wave is the switch Ti- in the positive half-wave the switch T2 - in the negative half-wave - for longer connected than in the area of low current level. Figure 6 shows the joint connection of the first and second switching units for a single switching unit for phase U, by means of joint switching and by a temporarily connected connection and disconnection of the corresponding power switches TI and T2 of the individual switching units the over-oscillations of the current can be drastically reduced, while the individual switching units or switching modules are connected in parallel via the inductance L3. In the switching according to FIG. 7, it is between the power socket Al of the first switching unit 1 of FIG. 7 for the generation of the positive fraction of the network current and the inductance L3 connected later by a thermistor forming the first element. of switching S2, likewise a second switching element S2 is provided between the power supply A2 of the second switching unit 2 of FIG. 8 for the generation of the negative fraction of the mains current and the inductance L3. Figure 9 shows the series switching of the switching units 1, 2 shown in figures 7 8, where the inductance L3 serves as a common inductive coupling. The DC voltage supplied is divided in this commutation composed of the switching units 1, 2 into two partial voltages of the same magnitude + Ud, -Ud. The two blind diodes Di, D2 are connected to ground. The diagram of Figure 10 illustrates, as the switch Ti and T2 as well as the switching elements Sl and S2 are connected, to obtain a phase of a sinusoidal current. During the positive half-wave of the sinusoidal current, the switch Ti is switched on and off in a prescribed pulse course. As long as the switching element Sl during the entire positive half-wave stays connected. The switch T2 and the switching element S2 remain disconnected during this time. Similar to the time course represented in Figure 5, by means of an action of a change of the states of connection and disconnection of the switch Ti, an indented sine current is produced. During the generation of the negative half-wave of the sinusoidal current, on the contrary, the switch Ti and the S are disconnected and the switch T2 and the Sl are connected, disconnect in an action at predetermined pulse and time distances, so that it is generated the negative half wave of the sinusoidal current. The switching element S2 is here during the entire connected negative half-wave. In the switching presented in Figure 11 s generates a rotary network current with the phases U, V, e where each time the first three and the three second switching units - as shown in Figure 9 - are connected to each other. In this exemplary embodiment, the current tap Al or A2 and the next corresponding switching element Ti or T2 connected other inductance Ll or L2 are input. In the switching of Figure 2 for generation d a three-phase rotary network current of the phases U, V W is the DC voltage fed divided into two partial voltage +. Udl and ± Ud2, which when added together give the continuous voltage joint. The corresponding diodes Di and D2 are here as shown in Figure 12 not connected to earth, but to -Udl or + Ud2. Figure 13 shows the scheme of a known alternating grinding, which by the antiparallel switching of the power switch T-T6 with the diode DI-D6 precisely allows an operation of four quadrants and with that l switching is applicable in many sides, in In case of a short-circuit connection of two switches, for example T and T2, however, there is also a large risk of a very strong short circuit, which can lead to the total destruction of the AC rectifier and possibly to the destruction of all the related devices. To generate the positive half-wave of the output sinusoidal current in the known rectifier, a connection and disconnection is made, for example, of the switch Ti and T2. for a semi-wave this means that many times during the Semi-WAVE IT AND T2 SWITCHES ARE DISCONNECTED IN SEQUENCE, WHAT AND STABILISTICALLY INCREASES CLA-RAMENTE THE PROBABILITY of a transverse circuit compared to the solution of the present invention of according to Figure 5. By means of the current branch according to the present invention, this is positive and negative cross-sections - See Figure 1 and Figure 2 are prevented in the composite or joint commutation of the individual switching units - see for example, Fig. 3- certain strong circuits. However, due to some false switching of the switches Ti and T2 in the embodiments of Figures 3, 4 and 6, such a short circuit will occur, the switches will be decoupled and protected by the inductivities 11 and 12. In the form e In accordance with Fig. 9, 11, the diodes Di and D2, as well as the mutants Sl = 2, reduce the danger of the transverse short circuit. The spatial structure of the two transverse branches - positive, negative - can also be stopped, so that the mechanical structure of the rectifier can be made more easily. With the concept of rectifier according to Fig. 3 or Fig. 4 and 6 as well as according to Fig. 9 and Fig. 11 and 12 can be built rectifiers with a very high power-. The decoupling impedances L 1 and L 2 between the switches of two connected switching units can simultaneously be used as an alt-frequency choke and also as filters for a dU / dt reduction. With this, the disturbing radiation towards the power switches T and T2 is drastically reduced already directly. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the products to which it refers.

Claims (13)

1. CLAIMS Having described the invention as above, s claims as property what is contained in the following: 1. - Alternating rectifier for power sinusoidal currents in an alternating current network with two switching units connected in parallel or series of which the first switching unit generates the positive part of the mains current and the second switching unit generates the negative part of the mains current where each switching unit has a switch and its blind diode with the connected in series and the two taps d current between the commutator and the blind diode.
2. 2. - The alternating rectifier according to claim 1, characterized in that the two switching units d by means of at least one inductivity s uncouple each other and by means of at least one other common inductivity are coupled to each other.
3. 3. - Alternating rectifier according to claim 1, characterized in that a first element or a second switching element preferably a thyriston is connected between the current tap point of the first or the second switching unit and a common inductivida that coupling to the two switching units,
4. 4. - Alternating rectifier according to claim 3, characterized in that, during the generation d the positive part of the mains current the first switching element is connected and the second switching element s disconnects. , and during the generation of the negative part of the network current the second switching element is switched on and the first switching element is switched off.
5. 5. - Rectifier according to one of the preceding claims, characterized in that the continuous tension is divided into a first partial DC voltage and a second partial DC voltage, and the first partial DC voltage is applied to the first switching unit for the generation of the positive part of the stream of re and la. second partial DC voltage is applied to the second switching unit for generating the negative part of the mains current, and the second switching unit is connected in series with the first switching unit.
6. 6. -Alternative rectifier according to claim 5, characterized in that the two partial continuous voltages have the same magnitude and the two blind diodes are connected to ground.
7. 7. - Rectifier according to one of the preceding claims, characterized in that the generation of a three-phase current is provided at least three first and three second switching units which are already connected center si.
8. 8. Rectifier according to one of the preceding claims, characterized in that the first the second switching units are installed separated from each other.
9. 9. - Rectifier according to one of the preceding claims characterized in that, for the generation of a semi-oscillation of a sinusoidal oscillation s connects and disconnects each time only one switch d a switching unit multiple times.
10. 10. - Rectifier according to one of the preceding claims, characterized in that for the generation of the positive semi-oscillation only the first switching unit and for the generation of the negative half-oscillation only the second switching unit e connected and is disconnects multiple times in a certain time states.
11. 11. - Rectifier according to claim or L 10, characterized in that, in the area of the minimum maximum current of a sinusoidal half-wave, the input pulses of the switch considered each time are longer than in the zon of the null step of a sinusoidal half-wave.
12. 12. - Rectifier according to one of the preceding claims, characterized in that multiple first and second units are joined to each other and form the current of a single phase, which can be three.
13. 13. - Wind energy converter or other direct current generator with an alternating rectifier according to one of the preceding claims.