Transistor T 1 a , on the other hand, is actuated by a clock signal corresponding to the network frequency of the input current I L1 , in this instance via the operational amplifier 10.
The potential can therefore be corrected significantly faster than the duration of a half-wave as a rule. It would naturally also be conceivable to raise only the first half-wave or lower only the second half-wave.
The method according to claim 7, wherein at least one of the switching elements S 1 a. Click for automatic bibliography generation. The connecting point of the switching elements S 1 a , S 2 a is connected to a connection, specifically to a phase connection L 1 , of an AC voltage input E. In reality, however, the input current I L1 changes its sign in the second half-wave.
T 6 b Transistor T 7. Again, it would naturally also be conceivable to superimpose a pulse during the first half-wave only or during the second half-wave only. From this, it may clearly be seen that transistors T 1 b and T 2 b can be actuated by the same pulse pattern U T1b of the DSP 9 because the control voltage U T1a for transistor T 1 a and the inverse control voltage for transistor T 2 a cause the pulse pattern U T1b to be active for only a half-wave of the input voltage U L1.
It is also of advantage if a phase shift between an input current and an input voltage is preset. In other words, the current is flowing across input L 1 and across output L 2.
Also illustrated are the input current I L1 and current I 1 in the top and current I 2 in the bottom connecting branch between the series circuit of diodes D 1 , D 2 and the series circuit of transistors T 1 a , T 1 b , T 2 a and T 2 b. The energy directed to capacitor C 1 during the positive half-wave therefore becomes slightly greater with a positive pulse and the energy directed to capacitor C 2 during the negative half-wave therefore becomes slightly less with a negative pulse.
In the example illustrated, it would naturally also be possible for inner transistors T 1 a and T 2 a to be actuated by the DSP 9 and the outer transistor T 1 b to be actuated by the operational amplifier 10 and outer transistor T 2 b to be actuated by the inverter 11. The voltage signals U S1 and U S2 are pulse width modulated sinusoidal signals so that at a relatively high switching frequency and due to the low pass effect of the inductance at connection L 1 for the input current I L1 indicated by broken lines, a sinusoidal input current I L1 is obtained.
The solid line again indicates the state in which the desired potential has been reached and therefore does not have to be actively adjusted. This signal is then forwarded to a current controller 6 and its output signal to a pulse pattern generator 7.
It is of advantage if the connecting point of the capacitors or diodes is connected to a neutral terminal of the AC voltage input. T 6 b and means for running a control algorithm, whereby the output voltage U A and said potential U C1 are provided as controlled variables, an input current I L1 , I L2 , I L3 at the AC voltage input E is provided as a manipulated variable and the switching elements S 1 a.
S 6 b Switching element t Time T 1 a. Naturally, however, any other current or any other current shape can be generated in the neutral wire N—provided it is connected. At this particular instant, no current is flowing across L 3.