JPH07225621A - Power saving device with voltage drop preventing function - Google Patents

Abstract

PURPOSE:To restore an output voltage to the same voltage as an input voltage by automatically detecting a drop of the input voltage by the voltage drop type power saving device which uses a transformer. CONSTITUTION:The single-phase three wire type single wiring coil transformer is constituted by winding main coils L1, L2, L4, and L5 connected to an input terminal around a single-phase core type core 1 in two circuit phases, winding plural exciting coils L3 and L6 around the core 1 and connecting them between end parts of the main coils L1, L2, L4, and L5 in those circuits, connecting the respective outputs of the transformer between the main coil L1 and exciting coils L3 and L6 of the respective circuits, connecting a zero-phase input terminal and the output terminals, winding and connecting plural demagnetizing coils L9 and L10 which correspond to the numbers of turns of the exciting coils L3 and L6 and generate voltages opposite in phase from the voltage of the main coil L1, connecting a voltage sensor 2 to the input terminals of the respective main coils, providing switches one of which turns on when the voltage value of the output terminal of the voltage sensor decreases or increases below or above a specific voltage while the other turns OFF, and connecting one switch between the exciting coils and the other between the demagnetizing coils.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage-down type power-saving device such as a transformer having a function of automatically restoring (backup) the input voltage when it drops below a certain voltage.

[0002]

2. Description of the Related Art Power saving devices such as two-phase and three-wire transformers are
As shown in Fig. 3, a main coil wound around a single-phase inner iron core
L₁, L₂And L_Four, L_Five2 phase winding and output these
Exciting coil L wound around the above cores between the ends₃, L₆
And L₇, L₈These are connected in series by winding
By connecting the midpoint of the coil and the zero-phase terminal s,
₂, L_FiveConnect the terminals r and t of the other phase from the output end of
It

In this case, the voltage taken out from the output terminals of the single-turn main coils L ₂ and L ₅ is surely lower than the input voltage, so that the power saving effect can be achieved.

For example, in the above circuit, if 100V is input between the R phase and the S phase, the voltage drops to 6V for the r phase and the s phase, and becomes 94V. If the load is constant (1Ω), I
₃ is 94A, the power is 8,836KW, and the power saving is 1,164KW from the input power of 10KW.

[0005]

However, in this power saving device, two exciting coils connected to the main coil are provided, and the exciting currents flowing through the exciting coils L ₃ , L ₆ and L ₇ , L ₈ are equal to each other. There are many loss currents inside the transformer because they are different. In addition, if there is a drop in the input voltage, the output voltage will drop more than expected, which may adversely affect the load.

The present invention has been made in view of the above points, and provides a power-saving device that reduces the loss current inside the transformer and has a good voltage balance, and automatically when there is a drop in the input voltage. The present invention provides a power saving device with a voltage drop prevention that detects a voltage and recovers the output voltage to the same voltage as the input voltage.

[0007]

SUMMARY OF THE INVENTION Therefore, according to the present invention, in a single-phase three-wire type or single-phase two-wire type single-winding coil type transformer, a plurality of sets of main coils connected to an input terminal are connected to a single-phase inner iron core. Two circuit phases are wound, and a plurality of exciting coils corresponding to each circuit of the main coil are wound in series and connected to the core between the ends of the main coil of each of these circuits. Further, each output terminal of the transformer is connected between the main coil and the exciting coil of each of the above circuits, and the zero-phase input terminal and the output terminal are mutually connected. Separately from this, a plurality of degaussing coils, which correspond to the number of turns of the respective exciting coils and generate a voltage having a phase opposite to the voltage of the main coil, are wound, and these degaussing coils are connected to each other.

Further, a separate voltage sensor is provided, the voltage sensor is connected to the input end of each of the main coils, and the voltage value detected by the voltage sensor drops or rises below a predetermined voltage at the output end of the voltage sensor. Then, a switch is provided in which one is turned on and the other is turned off. One of the switches is connected between the exciting coils and the other is connected between the degaussing coils. Also, this switch may be composed of two sets of thyristors.

[0009]

[Operation] When a voltage is input to the input terminal of the transformer,
An exciting current flows through each of the plurality of exciting coils, and a certain voltage drops due to the main coil. As a result, the voltage at the output terminal drops from the input voltage by the above-mentioned constant voltage. When the input voltage drops below a predetermined voltage value, the voltage sensor detects this and turns on one of the switches. So the lines of multiple degaussing coils are connected,
The other of the switches is turned off to turn off the excitation of the plurality of exciting coils. The voltage of the main coil induces a voltage having a phase opposite to that of the main coil in the degaussing coil to cancel the excitation of the main coil. As a result, the voltage drop at the main coil is eliminated, the voltage at the output terminal becomes the same value as the input voltage at the input terminal, and the voltage drop is suppressed.

Then, when the input voltage is restored and becomes equal to or higher than a predetermined voltage, the voltage sensor detects this and turns on the other switch, and an exciting current flows through each of the exciting coils. At the same time, one of the switches is turned off to disconnect each degaussing coil, and as a result, no current flows through each degaussing coil, which causes the main coil to drop a certain voltage again. In this case, the predetermined voltage value for detecting a drop of the input voltage below a predetermined voltage and turning on one switch is set to the predetermined voltage value for detecting the increase of the input voltage over a predetermined voltage and turning on the other switch. It is made smaller than a predetermined voltage value to have hysteresis.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. A plurality of main coils L ₁ and L ₂ connected to the input terminals R and T
2 and L ₄ and L ₅ are wound around the single-phase inner iron core 1 for two circuits, and between the ends of the main coils L ₂ and L ₅ of each of these circuits, wound around the core 1 and connected in series with each other. A plurality of connected exciting coils L ₃ and L ₆ are connected. Further, the output terminals r and t of the transformer are connected between the main coil L ₂ and the exciting coil L _{3 of} each circuit and between the main coil L ₅ and the exciting coil L ₆ of the above circuits, respectively, and the zero phase input is made. The terminal S and the output terminal s are connected to each other. Further, the core 1 is provided with the plurality of exciting coils L ₃
Degaussing coils L ₉ and L ₁₀ corresponding to the number of turns of L and L ₆ are wound, and these are connected in series.

Further, a voltage sensor 2 is provided, the voltage sensor 2 is connected to the input ends of the main coils L ₁ and L ₄ , and the changeover switches 3 and 4 are provided at the output end of the voltage sensor 2. Each of the changeover switches 3 and 4 is automatically switched when the voltage value detected by the voltage sensor 2 drops or rises below a predetermined voltage. Two sets of thyristors 5 and 6 are provided at the output ends of these changeover switches 3 and 4, respectively. The input and output ends (cathode, anode) of these thyristors 5 are the above-mentioned exciting coil L ₃
And L ₆ and the gate is connected to the changeover switch 3. The input and output ends (cathode, anode) of the thyristor 6 are connected to the degaussing coils L ₉ and L ₁₀ described above.
, And the gate is connected to the changeover switch 4.

In the case of this embodiment, for example, the input terminals R and S
When a voltage of 106 V is applied between them, each main coil L ₁ , L ₂ ,
L _4, L ₅ and a current flows to the exciting coil L _3, L _6, and 6V drop in the main coil _{L 1, L 2, L 4} , L 5, an output terminal t,
The voltage is 100 V between s. When the changeover switch 3 is turned on, the thyristor 5 is turned on, and the exciting coil L ₃ ,
An exciting current flows through L ₆ . Further, in this case, since the changeover switch 4 is off and the thyristor 6 is off, the degaussing coils L ₉ and L ₁₀ are disconnected.

When the input voltage drops below 97V for some reason, the voltage sensor 2 detects it, which turns on the changeover switch 4 and turns off the changeover switch 3 (FIG. 1 shows this state. Indicates). Therefore, the thyristor 5 turns off and the thyristor 6
Turns on. Therefore, the exciting current does not flow through the exciting coils L ₃ and L ₆ , but the thyristor 6 is turned on when the changeover switch 4 is turned on, whereby the degaussing coil L ₉ is turned on.
And a circuit connecting L ₁₀ are connected, and the main coil L ₁ ,
L _2, L _4, L primary coil L ₁ In these degaussing coil L ₉ and L ₁₀ by the voltage of _5, L _2, L _4, the voltage of the L ₅ opposite phase is induced, the main coil L _1, L ₂ , L ₄ and L ₅ are canceled. Therefore, the main coils L ₁ , L ₂ , L ₄ , and L ₅ do not function as inductors, no voltage drop occurs, and the output terminals t and s
Between them, the voltage is 97 V or less, which is the same as the input voltage. When the input voltage drops to 97V, the output voltage is backed up to the same voltage as the input voltage.

When the input voltage is restored and rises from 96 V, the voltage between the output terminals t and s also rises accordingly. Then, when the input voltage becomes 99V, the voltage sensor 2 detects this and turns on the changeover switch 3 and turns off the changeover switch 4. As a result, the thyristor 5 is turned on and the thyristor 6 is turned off. Therefore, an exciting current flows through each of the exciting coils L ₃ and L _6, and the main coils L ₁ and L ₂ ,
L _4, L ₅ in to 6V minute drops, the output terminal t, the voltage between s 1
It becomes 00V. FIG. 2 shows a graph showing changes in these input voltage and output voltage.

In this case, the predetermined voltage for backing up the output voltage due to the drop of the input voltage and the predetermined voltage for canceling the backup due to the rise of the input voltage are set to different levels and hysteresis is provided, so that these switching can be smoothly performed. .

Although the single-phase, three-wire system has been described in the above embodiment, the input terminal R-T is used when used in a single-phase, two-wire system.
When a similar voltage is input between the phases and a load is connected between the output terminals r-t, the output voltage drops to 6V as in the above embodiment, which saves power. In the above embodiment, the thyristor 5,
6 is used, the present invention is not limited to this, and the same effect can be obtained by providing an appropriate switch.

[0018]

By using the device of the present invention, the output voltage can be surely lowered, whereby the power consumption can be reduced and the power can be saved. When the input voltage drops below a predetermined voltage, the number of windings of the exciting coil may be switched by a switch or thyristor, or the main coil may be switched to raise the output voltage. It was impossible to restore the same voltage as the input voltage. In the present invention, it is common knowledge that the transformer is always used by exciting the iron core. However, by demagnetizing the transformer, the function of the main coil as an inductor disappears, and the output voltage becomes the input voltage. It becomes the same voltage as. Therefore, the influence on the load when the input voltage drops abnormally is suppressed as much as possible.

A switch using a thyristor as a switch for connecting the circuit of the exciting coil and a switch for connecting the circuit of the degaussing coil is suitable for this device because the switching structure becomes extremely simple in addition to the above effects.

Further, according to the present invention, the two-phase coil winding of the single winding coil on the single-phase inner iron core causes a voltage inducing phenomenon between them inside the transformer, thereby improving the voltage balance. Further, in the present invention, since the exciting current flows between the R phase and the T phase, the exciting currents flowing through the plurality of exciting coils are the same, and the loss current inside the transformer can be suppressed to be small.

[Brief description of drawings]

FIG. 1 is a schematic configuration circuit diagram of an embodiment of the present invention.

FIG. 2 is a graph showing changes in input voltage and output voltage according to the device of the present invention.

FIG. 3 is a circuit diagram of a conventional power saving transformer.

[Explanation of symbols]

1 Single-phase inner iron core 2 Voltage sensor 3 Changeover switch 4 Changeover switch 5 Thyristor 6 Thyristor L ₁ Main coil L ₂ Main coil L ₄ Main coil L ₅ Main coil L ₃ Excitation coil L ₆ Excitation coil L ₉ Demagnetization coil L ₁₀ Degaussing coil

Claims (2)

[Claims] 1. In a single-phase three-wire or two-wire single-winding coil type transformer, a main coil connected to an input terminal is wound around a single-phase inner iron core in two circuit phases, and a main coil of each of these circuits is wound. Between the ends, a plurality of exciting coils are wound around the core and connected, each output terminal of the transformer is connected between the main coil and the exciting coil of each circuit, and a zero-phase input terminal and an output terminal are connected. Separately from this, a plurality of degaussing coils corresponding to the number of turns of each exciting coil and having a voltage of a phase opposite to the voltage of the main coil are wound around the core, and these degaussing coils are connected to each other. A voltage sensor is provided and connected to the input end of each main coil, and at the output end of this voltage sensor, a switch that turns on one and turns off the other when the voltage value of the voltage sensor drops or rises below a predetermined voltage. Provided, this switch A power saving device with voltage drop prevention, characterized in that one of the switches is connected between the exciting coils and the other is connected between the demagnetizing coils. 2. The power saving device with voltage drop prevention according to claim 1, wherein the switch comprises two sets of thyristors.