JPH03253228A - Tapped ferroresonance three-phase power balancer - Google Patents

Abstract

PURPOSE:To balance three-phase input currents by a method wherein loads are obtained between taps provided at the middle part of the windings of the respective saturation reactors of respective parallel resonance circuits which are connected to each other in a -connection and output terminals which are not the terminals to which the respective saturation reactors are not connected through respective transformers. CONSTITUTION:Linear reactors composed of gapped cores 1, 2 and 3 and windings 10, 11 and 12 applied to the gapped cores 1, 2 and 3 are connected to the respective lines of a three-phase input side and the one side terminals of the linear reactor are used as input terminals 22, 23 and 24. Saturation reactors 4, 5 and 6 whose cores are used in a saturated range and capacitors C are connected between respective output side terminals 25, 26 and 27 in parallel with each other to provide parallel ferroresonance circuits. The respective load currents of the respective phases are so shunted as to make magnetomotive forces in the respective saturation reactors have magnitudes equal to each other and directions opposite to each other. Further, the reactive currents of the respective phases are synthesized with the load currents to balance three- phase input currents.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tapped iron-resonant three-phase power balancing device suitable for a three-phase human power balancing power supply used in factories, high-rise buildings, etc. [Prior Art] Electricity A conventional balancing device that aims to balance the three-phase input side of a three-phase power source, such as a railway, with electric cars on the up and down lines as loads, is a three-phase/two-phase system as shown in Figure 4. There is a Scotto transformer as a converter. This device uses two single-phase transformers, one end of the secondary winding of the T-seat transformer (Tt) is connected to the midpoint 0 of the secondary winding of the main transformer (Tm), and the primary side Connect the remaining three terminals to the three-phase power supply RU, V, and W. A secondary example is to connect terminals of the same polarity and set the neutral point to 0-
If so, two-phase crossover will be obtained between 0- and the other two terminals U and V.

In addition, as shown in Figure 5, a linear inductance was connected between one line of the output side of a three-phase iron-resonant constant voltage transformer, a capacitor was connected between the other line, and a capacitor was connected between the remaining lines. Power supplies have also been developed that balance three-phase inputs against single-phase loads.

In addition, the symbols in FIGS. 4 and 5 are IUI IUp F.
t is current, VWt ”LI+ VWt V a b+
ELIt Eu is voltage, C, Ca are capacitors, L, L
a is a linear reactor part, SR is a saturated reactor part,
Tt and Ten indicate transformers.

[Problems to be Solved by the Invention]However, in the device shown in FIG. 4, there is a problem that unless the output load impedances of each phase of the two-phase output are equally balanced, the three-phase input side will not be balanced. be. In addition, in the device shown in Figure 5, only a single-phase load is output, and unbalanced two-phase and three-phase loads cannot be taken out at the same time.The only way to balance the three-phase input side is to adjust the parallel ferro-resonance characteristic itself. However, there are limits to this, and it is unbeatable for balancing three-phase input currents over a wide range of loads.

The present invention is an attempt to solve such problems.Even if a single-phase load and an unbalanced two-phase or three-phase load are simultaneously taken from the three-phase output terminal, the saturation reactor can be installed to handle changing loads. By adjusting the tap position in advance, the parallel iron resonance characteristic to be used can be matched to the theoretical parallel resonance characteristic Zt at which the three-phase input current is balanced against load changes. It is an object of the present invention to provide a balanced fero-resonant three-phase power balance device.

[Means for solving the problem] A linear reactor is provided on each line on the three-phase input side, and a capacitor and a saturation reactor are connected in parallel between each line on the three-phase output side to form a parallel iron-resonant circuit. Connect the transformer between the tap provided in the middle of the winding of each saturation reactor of each connected parallel ferro-resonant circuit and the other output copper terminal of the saturation reactor excluding the connected terminals. It is characterized by obtaining a load.

[Function] With the above-mentioned configuration, the respective load currents flowing through the two Confucian windings at the tap positions provided in the saturation reactor due to the three-phase voltage input to the second steel are such that the magnetomotive force in the saturation reactor is mutually Each phase is divided equally in the opposite direction, and at the same time, the input is delayed to the parallel iron resonant circuit connected between each line,
A leading reactive current is passed, and the reactive current of each phase is used to balance the three-phase input current by combining it with the load current.

[Example] Hereinafter, a tapped iron-resonant three-phase power balance device as an example of the present invention will be explained with reference to the drawings. Fig. 1 is an overall configuration diagram, Fig. 2 is an electric circuit diagram thereof, and Fig. 3 is a diagram. is a graph for explaining each effect.

FIG. 1 shows a specific configuration of the present invention. Each wire on the three-phase input side has a magnetic core with a gap 1 (2, 3) has a winding 10 (
11, 12) is connected, one of which becomes the input side terminal 22 (23゜24), and its output copper terminal 25 (26, 27). A saturation reactor 4 using a saturated part of the magnetic core between each wire. (5, 6) and a capacitor C is connected in parallel to each of them to form a parallel iron-resonant circuit.

In addition, the tap 13a (14a, 15a) provided on the winding 13 (14°15) of this saturation reactor and the other terminal 25 other than both terminals to which the parallel iron resonant circuit is connected
(26, 27) and the secondary winding 16 (17, 18) of the transformer 7 (8, 9), and the secondary inverted winding 19
Connect (20, 21) △ and three-phase output terminal 2B (
29, 30).

Next, the operation of the configuration shown in FIG. 1 will be explained using the equivalent circuit shown in FIG. 2. In FIG. 2, reference numerals indicate linear reactors each having a magnetic core 1 (2, 3) connected in series with each line on the three-phase input side and each having a gap. code S
R is a saturation reactor that has the voltage-current characteristics shown in Figure 3 when an input voltage is applied, and a capacitor C is connected to both terminals of the reactor to form a parallel iron-resonant circuit. The circuit is △ connected.

In addition, the winding 13 wound around this saturation reactor magnetic core
(14, 15) and the other terminal except for the terminals connected to the saturation reactor, connect the transformers respectively, and connect the outputs by △ to load the three-phase load. , but good results can be obtained with a Y connection as well.

Here, the parallel iron resonance circuit of the saturation reactor SR and the capacitor C has parallel iron resonance characteristics as shown in FIG.

The characteristic shown by the dotted line in Fig. 3 is, for example, the parallel resonance characteristic Z when the three-phase input side elements are balanced when the tap position of the saturation reactor winding in this device is the midpoint and the load is a resistive load. This is a theoretical value, and the characteristics are close to parallel iron resonance characteristics.

Therefore, in this device, the theoretical value of the parallel resonance characteristic shown by the dotted line can be easily adjusted by the tap position, so the circuit is simple and highly reliable, making it suitable as a three-phase input power balancing device.

[Effects of the Invention] As detailed above, the tapped iron-resonant three-phase power flattening device of the present invention provides the following effects and advantages.

(1) The three-phase input side is balanced against unbalanced three-phase loads, including no-load, and their load changes.

(2) The circuit configuration is simple, and the human power factor, efficiency, and input current waveform are good.

(3) Due to items (1) and (2) above, it exhibits high practicality as a three-phase power balanced power source used in factories, high-rise buildings, etc.

[Brief explanation of drawings]

Figures 1 to 3 show a tapped iron-resonant three-phase power balance device as an embodiment of the present invention, in which Figure 1 is an overall configuration diagram, Figure 2 is its electrical circuit diagram, and Figure 3 is an electrical circuit diagram. These are graphs for explaining the respective effects, and FIGS. 4 and 5 are electrical circuit diagrams of conventional three-phase power balancing devices, respectively. 1.2.3...Gap core, 4,5,6...Saturation reactor core, ? , 8.9...Transformer magnetic core, 10, 11
．． 12...Next winding, 13°14.15...Saturation reactor winding, 13a. 14a, 15a...Tap, 16, 17. 18--Primary winding of output transformer, 19, 20.21...Secondary winding of output transformer, 22-24...Input side child, 25-27 ...Output network terminal, 28-30...Output terminal, C...Capacitor, L...Linear reactor, SR...Saturation reactor,
Z: Parallel iron resonance characteristics, o: Resonant voltage, Xo: Capacitive reactance, Zt: Theoretical value of parallel resonance characteristics, T
U+ TutT, output transformer

Claims (1)

[Claims] Each wire on the three-phase input side has a linear reactor, and a capacitor and a saturation reactor are connected in parallel between each three-phase line on the output side to form a parallel iron-resonant circuit, and each of the parallel iron-resonance circuits is △ connected. The load is obtained by connecting a transformer between a tap provided in the middle of the winding of each saturation reactor and another output terminal other than the connected terminals of the saturation reactor. Ferro-resonant three-phase power balance device with tap