RU117051U1 - THREE-PHASE VOLTAGE SYNTHESIS WITH POWER COMPENSATION - Google Patents

Abstract

A three-phase voltage synthesizer with power compensation, containing a three-phase power transformer and a load, characterized in that the synthesizer is equipped with a phase-shifting device with an input connected to an alternating current source and three outputs, to which the primary winding of a three-phase power transformer connected by a star is connected, secondary phase windings which are connected in series with each other and with the external section of the circuit, the winding of the first output is dividing, the second is increasing, the third is lowering, and in the secondary windings the beginning of the second winding is connected to the beginning of the first, and the end of the second winding to the end of the third, to the end of the first and the beginning of the third a resistive load is connected in parallel through the inductor, and a capacitor is connected in parallel to the second winding.

Description

The utility model relates to the field of electrical engineering and can be used to power electrical receivers with electrical energy.

A known energy converter comprising a power source, a power transformer with a primary and secondary winding, to which an active load is connected, a parallel oscillatory circuit tuned to current resonance and a current transformer, the oscillatory circuit being connected in parallel with the output of the power source, the primary winding of the current transformer is connected in series between the coil inductance and capacitor, and the secondary winding of the current transformer through the first rectifier is connected to the primary winding of the power about the transformer and shunted by the second rectifier (patent for utility model of the Russian Federation No. 866364).

The known energy converter is closest to this utility model. The disadvantage of this converter is the use of semiconductor diodes in the mode of half-wave rectification, which leads to a significant distortion of the shape of the sinusoidal voltage and current curves and the associated losses, the result is low efficiency.

The technical result of the utility model is the amplification of reactive power and its conversion into active.

The specified technical result is achieved in that in a three-phase voltage synthesizer with power compensation, containing a phase-shifting device with an input connected to an AC source and three outputs, to which the primary windings of the power isolation transformers are connected, the secondary windings of the first and second transformers are connected in series with each other and with active load, ACCORDING TO THE USEFUL MODEL, the ends of the windings are interconnected, and the active load, secondary windings are connected to the beginnings and the second and third transformers are also connected in series with each other and with the inductor, and the beginning of the secondary winding of the third transformer is connected to the end of the secondary winding of the second transformer, and an inductance coil connected to the beginning of the secondary winding of the second transformer and the end of the secondary winding of the third transformer is parallel to the secondary winding the first transformer connected in series with a resistor and an inductor.

Figure 1 presents a circuit diagram of a three-phase voltage synthesizer with power compensation;

figure 2 presents a vector diagram explaining the operation of a three-phase voltage synthesizer with power compensation;

A three-phase voltage synthesizer with power compensation contains a phase-shifting device 1 (Fig. 1) with an input connected to an AC source and three outputs to which the primary windings of the power isolation transformers 2, 3 and 4 are connected, the secondary windings of the transformers 2 and 3 are connected in series between themselves and with an active load of 8, with the ends of the windings connected to each other, and connected to the beginning of the active load 8, the secondary windings of transformers 3 and 4 are also connected in series with each other and with coils ohm inductance 7, and the beginning of the secondary winding of the transformer 4 is connected to the end of the secondary winding of the transformer 3, and to the beginning of the secondary winding of the transformer 3 and the end of the secondary winding of the transformer 4 is connected an inductor 7, the secondary winding of the transformer 2 is connected in parallel with the resistor 5 and connected in series with each other inductor 6.

A three-phase voltage synthesizer with power compensation works as follows. At the input of the phase shifting device 1, an alternating voltage of a certain frequency is supplied. Three variable voltages of the same frequency as at the input are removed from the outputs of the phase shifting device, and the phase of the voltage of the first output U _{1 is} ahead of the voltage phase of the second output U ₂ by 45 degrees, and their value is the same. Due to the counter-serial connection of the secondary windings, the voltage U ₂ is subtracted from the voltage U ₁ , as a result, the total voltage ΣU is obtained, which is applied to the load 8, as a result, the load current I _H starts to flow in the load circuit. The RL circuit, consisting of an inductor 6 and a resistor 5, is connected in parallel with the secondary winding of the power isolation transformer 2 and forms one compensation branch. Transformer voltage phase 4 U _ext . is shifted relative to the phase of the total voltage ΣU by 180 degrees, and its value is such that when adding its vector to the voltage vector U ₁ , a compensation voltage vector U _{k1 is} obtained, ahead of the phase of the voltage vector U _add . at an angle of 90 degrees. The source obtained by adding the above voltages with a compensation voltage U _{k1 is} loaded on the inductor 7, forming a second compensation branch. As a result, the currents flowing along these branches compensate the load current for each of the transformers, as a result of which, the resulting current of transformers 2 and 3 is equal to zero. Only the mode of consumption of active power by transformer 4 remains, but it is two times less than the active power in the load circuit.

The vector diagram depicted in figure 2 graphically shows the physical processes occurring in the circuit of the resonant transducer, where

U ₁ - voltage transformer 2 (V);

U ₂ - voltage transformer 3 (V);

U _ext . - voltage of the transformer 4 (V);

ΣU is the total voltage of two transformers 2 and 3 (V);

U _k1 - total compensation voltage of transformers 3 and 4 (V);

I _H - load current (A);

I _k1 - current branch compensation transformer 3 (A);

I _K2 - current branch compensation transformer 2 (A);

f ₁ - phase angle between the load current and the voltage of the transformer 3 (degree);

f ₂ - phase angle between the load current and the voltage of the transformer 2 (degree).

Claims (1)

A three-phase voltage synthesizer with power compensation, comprising a three-phase power transformer and a load, characterized in that the synthesizer is equipped with a phase-shifting device with an input connected to an alternating current source and three outputs, to which a primary three-phase transformer connected by a star is connected, secondary phase windings which are connected in series with each other and with the external part of the circuit, the winding of the first output is separate, the second is raising, the third is lowering, In the secondary windings, the beginning of the second winding is connected to the beginning of the first, and the end of the second winding to the end of the third, to the end of the first and the beginning of the third, an active load is connected in parallel through the inductor, and a capacitor is connected in parallel to the second winding.