Electric power conversion systems – Current conversion – Using semiconductor-type converter
Patent
1999-05-14
2000-12-05
Riley, Shawn
Electric power conversion systems
Current conversion
Using semiconductor-type converter
363 56, H02M 75387
Patent
active
061575569
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention relates to an inverter for inputting sinusoidal currents into an alternating current network or a public power supply network.
BACKGROUND
The power switches used to form such inverters are almost exclusively executed in a three-phase bridge configuration, as shown in FIG. 13. Such an inverter generates multi-phase alternating current with three phases U, V, and W, from a dc voltage source. The antiparallel switching of power switches T1 to T6, shown in FIG. 13, using corresponding diodes, enables four-quadrant operation, and thus allows many applications for such an inverter circuit.
The disadvantage of such an inverter circuit is that in the event of a short circuit across two switches, e.g. T1 and T2, extremely large energy flows occur, which typically causes complete destruction of the inverter, perhaps even starting a fire which leads to the destruction of all connected system components.
SUMMARY OF THE INVENTION
The objective of the present invention is to improve resistance to short circuits occurring and to reduce the risks thereof.
This invention achieves this objective through an inverter including two switching units connected in either parallel or series, a first of the switching units generating positive components of the [mains] sinusoidal current and the second switching unit generating negative components of the current. Each of the switching units includes a respective switch and a corresponding capacitive diode connected in series, and a corresponding tap-off located between said respective switch and said respective capacitive diode, said two switching units each being decoupled by at least one respective inductance and coupled through at least one common inductance to an output.
The invention is based on the principle of using only a single switching unit in the generation of a semi-oscillation of a sinusoidal oscillation. Thus, a different switching unit is used for generating the positive semi-oscillation of the sinusoidal oscillation than is used for generating the negative component. As a result, only one switch of a switching unit is clocked or actuated in the generation of a positive semi-oscillation, while a different switch is active in the generation of the negative semi-oscillation of a sinusoidal current. The danger of a short circuit between the two switches is thus limited to the time during the changeover from the positive to the negative, or from the negative to the positive, semi-oscillation.
In addition, only a single switching unit is responsible for the generation of a semi-oscillation of a sinusoidal oscillation, so that the switching units that are responsible for different semi-oscillations can be physically separated. This improves the safety of the switching system components and simplifies the spatial arrangement.
A preferred embodiment of this invention is characterized by the fact that a supplied dc voltage is divided into a first and a second partial dc voltage. The first partial dc voltage is used, e.g. for the generation of the positive component of the mains current, and the second partial dc voltage is used for the generation of the negative component. As an example, let the values of the two partial dc voltages be 660V each, resulting in a total dc voltage of 1320V. The components used in the first switching unit only have to be able to process the first partial dc voltage, while the components of the second switching unit are maximally loaded by the second partial dc voltage. The equivalent is true for inductances and potential semiconductor switching elements connected to the switching units. Thus, considerable cost savings are possible since the components do not have to be designed to be as puncture proof as in the known inverter of FIG. 13. In other words, the output power of the whole inverter can be doubled, while using components that only have to process a partial dc voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained further in the following by drawings of an embodiment example.
FI
REFERENCES:
patent: 4585986 (1986-04-01), Dyer
patent: 4768141 (1988-08-01), Hubertus et al.
patent: 4951187 (1990-08-01), Herbert Stemmler
patent: 5025360 (1991-06-01), Latos
patent: 5657219 (1997-08-01), Stanley
Dec. 1988, Erich Hau "Windkraftanlagen", Springer Verlag, pp. 287-310.
LandOfFree
Switched inverter circuit providing increased short circuit prot does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Switched inverter circuit providing increased short circuit prot, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Switched inverter circuit providing increased short circuit prot will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-967176