Half-bridge inverter

Details Half-bridge inverter Half-bridge inverter

2000-08-09

2001-07-24

Han, Jessica (Department: 2838)

Electric power conversion systems

Current conversion

Using semiconductor-type converter

C363S098000

Reexamination Certificate

active

06266259

ABSTRACT:

The present invention relates to a half-bridge inverter in accordance with the preamble to claim
1
.
Such a half-bridge inverter known from the prior art (see DE-A 197 22 124) is shown in
FIG. 1. A
first and a second input terminal E, N form an input, which has a storage capacitor C
3
connected in parallel with it. Connected in parallel with the storage capacitor C
3
is, on the one hand, a varistor, i.e. a nonlinear resistor, as a surge arrester, which ensures the necessary surge strength in practice, and also the series circuit comprising a first and a second coupling capacitor C
1
, C
2
, the midpoint of said series circuit being connected to the first output terminal B of the half-bridge inverter. In this arrangement, the coupling capacitors C
1
, C
2
form the passive bridge path of the half-bridge inverter. The active bridge path of the half-bridge inverter, comprising a first switch S
1
and a second switch S
2
, is connected by its midpoint to the second output terminal A of the half-bridge inverter via an inductor L
1
, the inductor L
1
acting as a polarity-reversal inductor. Connected in parallel with the switches S
1
and S
2
, which are operated in push-pull mode, are a respective freewheeling diode D
1
, D
2
and a respective polarity-reversal capacitor CS
1
, CS
2
.
The first disadvantage of the half-bridge inverter shown in
FIG. 1
is that, although the alternating current flowing through C
3
is filtered by C
3
, this is not sufficient in practice, with the result that unwanted perturbations are produced at the input E, N. For the application instance where the circuit is designed to provide a high-frequency AC voltage on the terminals B, A, problems arise with regard to radio interference suppression. In addition, the inductor L
1
carries both the current load and the magnetization load. This means that the inductor L
1
needs to have large dimensions, which results in an undesirably high space requirement.
The object of the present invention is therefore to eliminate these disadvantages, and in particular to provide a half-bridge inverter which can be produced with a relatively small design.
This object is achieved by the disclosure of claim
1
.
The half-bridge inverter according to the invention has the advantage that the current load and magnetization load is split between two inductors. The current load on each inductor L
1
, L
2
is therefore half that of the current load on the inductor L
1
shown in FIG.
1
. The copper losses are thus now a quarter. This allows relatively small components to be used for production and thus reduces the space requirement on a circuit board. Particularly for relatively high powers, production is therefore greatly simplified. In the case of the subject matter of the invention, the storage capacitor C
3
is advantageously no longer arranged between the input terminals E, N, but instead is virtually at the other end of the circuit. Assuming that the half-bridge inverter has been designed for high frequency, the high-frequency charge reversal operations are thus as far away as possible from the input terminals E, N, so that the perturbations of the charge reversal operations in C
3
have much less of an influence on the input E, N than is the case in the prior art. With particular advantage, the position of the inductors L
1
, L
2
between C
3
and the passive half-bridge path comprising the coupling capacitors C
1
, C
2
increases the filter order by two orders, as seen from the input E, N. This results in a significant improvement in radio interference suppression and also in an increase in the surge strength, provided that a surge arrester is connected in parallel with C
3
. The filter to be provided in a preliminary stage to the left of the input E, N in
FIG. 2
can therefore be of simpler design.
In addition, it should be pointed out that the arrangement shown in FIG.
1
—as seen from the input terminals E, N—has only a first-order filter, since all the capacitors and the surge arrester VAR connected in parallel with the storage capacitor C
3
are connected in parallel.
Provision may be made for the first switch to have a first freewheeling diode connected in parallel with it and for the second switch to have a second freewheeling diode connected in parallel with it. In addition, provision may be made for a first polarity-reversal capacitor to be arranged in parallel with the first switch and/or for a second polarity-reversal capacitor to be arranged in parallel with the second switch.
The optional surge arrester VAR may be in the form of a nonlinear resistor, in particular in the form of a varistor.
With particular advantage, the capacitance value of the first coupling capacitor can be essentially the same as the capacitance value of the second coupling capacitor. The capacitance value of the storage capacitor, which in the half-bridge inverter according to the invention acts as a back-up capacitor for the active bridge path, is preferably twice the capacitance value of the first and/or of the second coupling capacitor.
In one particularly advantageous embodiment, the first inductor is coupled to the second inductor. This enables not just one variant to be produced, in which the first and second inductors are wound on a single core, but rather the coupling can also be designed to be such that the principal inductances of the first and second inductors cause the input current to be smoothed, and that the leakage inductances of the first and second inductors act as a polarity-reversal inductance.
Further advantageous refinements of the invention can be found in the dependent claims.


REFERENCES:
patent: 4914558 (1990-04-01), Flickinger
patent: 5303140 (1994-04-01), Shimizu
patent: 5875103 (1999-02-01), Bhagwat et al.
patent: 197 22 124 (1998-12-01), None

Affiliated with

Also associated with

Rating

Half-bridge inverter does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Half-bridge inverter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Half-bridge inverter will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2545612