SU591999A1 - Self-sustained inverter - Google Patents

Description

(54) AUTONOMOUS INVERTER

of the transformer on the ring core with magnetic RMA.

This goal is achieved by the fact that the secondary winding is located on the output transformer and connected in series with a reverse rectifier.

FIG. 1 is a schematic diagram of an autonomous inverter; in fig. 2 - its output transformer.

A stand-alone inverter consists of a unit 1 containing controllable valves with limited switching capacitors, a transformer with a rotating magnetic field, made on a ring core 2 with grooves of the stator type of an asynchronous machine and a reverse rectifier 3.

In the slots of the core 2, there is an annular bias 4 winding, covering the core rom, the primary two-phase winding 5, the auxiliary two-phase winding 6, each phase coaxial with the corresponding phase of the primary winding 5, as well as the output three-phase winding 7 having taps from each phase.

Each phase of the primary winding has leads from the middle, which are connected together and connected to the power supply terminal. The phases of the auxiliary winding are closed to capacitors 8 and 9, respectively. The inputs of the rectifier 3 are connected to the output winding taps. The output of the rectifier 3 is connected through a series-connected magnetic biasing winding to the same terminals of the DC power source. In this case, the voltage difference between the rectifying bridge and the DC source is applied to the bias winding.

When the inverter is connected, the primary two-phase winding 5 creates two pulsating magnetic fields whose axes are shifted in

JJ, -,

space and time angle -g-. The iodine is influenced by the winding 6 closed on the capacitors 8 and 9, the pulsating fields become sinusoidal, and the resultant field is circularly rotating. The rotating magnetic field, the intersection of the turns of the three-phase winding, induces a symmetric three-phase, almost sinusoidal voltage in the phases of this winding. The capacitance of the capacitors 8 and 9 is chosen in such a way that the maximum inductive load current is compensated. When the load decreases, the compensation is violated. Unit 1 and windings 5 and 6 of the transformer will be loaded with capacitive current. As a result, the output voltage of the inverter, and hence the output voltage of the converter, should increase significantly. But this

does not occur, since even a slight increase in the output voltage leads to an increase in the voltage at the output of the rectifier 3. As the voltage difference between the rectifier and the power supply is applied to the bias winding, the increase in the rectifier voltage by 1-2% leads to an increase The bias current is several times compared with the nominal load mode. The increase in bias leads to an increase in the magnetizing current consumed by the primary winding from the inverter. Since the magnetizing current is in antiphase with the capacitive current, the inverter and the primary winding are unloaded from the capacitive current, and the voltage increases slightly. With a strong increase in load, the output voltage decreases, the voltage at the output of rectifier 3 becomes less than the voltage of the power source, and the current through the magnetic biasing winding does not flow at all. Since the power of a transformer is usually somewhat higher than the maximum load, then by varying the magnetising current from minimum to nominal magnetising, a transformer with a rotating magnetic field can be used as a co-amplifying device controlled as a function of the output voltage.

The proposed solution allows us to simplify the autonomous inverter circuit, reduce its size and weight, and increase its reliability and efficiency.

Claims (2)

1. Kovalev, F. I., Mostkova, G. P., et al. Stabilized autonomous inverters with sinusoidal output voltage, p. 7- 19, M., “Energie, 1972. 2. The copyright certificate number 469195, cl. H 02 M 7/515, 1975. 9ui.i