JP3413346B2 - Protection circuit of power saving transformer with autonomous switching device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power-saving device such as a transformer, so that even when the input voltage drops or rises outside a certain set voltage range, the voltage within the set voltage range is set as the output voltage. In particular, the present invention relates to a protection circuit for a power saving transformer having a function of autonomously adjusting.

[0002]

2. Description of the Related Art A power-saving transformer (see Japanese Unexamined Patent Publication No. 8-191542) equipped with a self-switching automatic switching device for raising and lowering a pressure according to the present applicant (see Japanese Patent Application Laid-Open No. 8-191542) has a single-phase three-wire type or a two-wire type single winding. In the coil type transformer, two sets of main coils L1, L2 and L5, L6 connected to the input terminals R, T are wound around the single-phase inner iron core (9) in two circuit phases, and the main coil L2 of each of these circuits is wound. And L6, a plurality of sets of exciting coils L3, L wound around the core (9) and connected in series with each other between the ends thereof.
7 and L4, L8 are connected by a plurality of combinational wirings, and a plurality of sets of thyristors (1, 2, 3, 4, which are turned on and off according to the voltage value detected by the voltage sensor connected to the input terminal are connected. 5, 6, 7, 8) are provided between the ends and between the exciting coils to turn on the thyristors (1, 2, 3, 4, 5, 6, 7, 8) of each set.
A configuration in which one or more sets are connected or cut between the ends and between the exciting coils by turning off, and the output voltage with respect to the input voltage can be autonomously switched to a circuit that steps up, equalizes, or steps down the output voltage without interruption. Had.

[0003]

However, even in the conventional power-saving transformer, when power is supplied to the receiving transformer in the receiving equipment, a transient phenomenon occurs in the receiving transformer due to the balance with the phase advancing capacitor. Inrush current of several tens of times the capacity of the device flows into the voltage adjustment circuit of power-saving equipment, and semiconductor switches such as control circuits and thyristors often exceed the withstand capacity and are damaged.

[0004]

In order to solve the above problems, the present invention provides a time difference closing circuit on the output side of the main coil so that the inrush current does not flow into the voltage adjusting circuit. That is, in a single-phase three-wire or two-wire single-winding coil type transformer, two sets of main coils connected to the input terminals are wound around the single-phase inner iron core in two circuit phases, and the main coil of each of these circuits is wound. Between the ends, a plurality of sets of exciting coils wound around the core and connected in series with each other are connected by a plurality of combination wirings, and turned on and off depending on the voltage value of the voltage sensor connected to the input terminal. A plurality of sets of thyristors are provided between the ends and between the exciting coils, and one set or a plurality of sets between the ends and the exciting coils are connected or cut by turning on and off the thyristors of each set. In addition, a time difference closed circuit is installed on the output side of the main coil of the power-saving transformer with a step-up / down same-voltage autonomous switching device that can autonomously switch the output voltage against the input voltage to a circuit that boosts, equalizes, or lowers the voltage without interruption. It has been solved by the Rukoto.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION According to the power saving transformer of the present invention,
When the input voltage drops or rises so as to deviate from the voltage value within the set range, the voltage sensor detects this and the thyristor that receives the output signal from this voltage sensor controls the combination of the above multiple sets of exciting coils. By adjusting the drop rate of the input voltage value or conversely increasing the voltage, it is possible to always output the voltage value within the set range. Further, when the input voltage value is the same as the voltage value within the set range and the voltage drop or increase is unnecessary, the same voltage as the input voltage can be output without dropping or increasing the voltage. It has become. In addition, when the input voltage is decreasing and when it is increasing, the input voltage value for switching between the rate of voltage decrease and the rate of increase is made different to have hysteresis.
It eliminates the machine's misjudgment when switching the excitation coil and prevents the coil from being overloaded. As a main feature of the present invention, by providing a time difference circuit on the output side of the main coil, it is possible to prevent an inrush current from the outside from flowing into the voltage adjustment circuit and prevent damage to the thyristor.

The present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration circuit diagram of a power-saving transformer of the present invention. As shown in the circuit diagram, a plurality of main coils L1, L2 and L5, L6 connected to input terminals R, T are connected to a single-phase inner iron Shaped core (9) wound in two circuit phases, and between the ends of the main coils L2 and L6 of each of these circuits, a plurality of sets of exciting coils L3 wound around the core (9) and connected in series with each other. , L7
And L4 and L8 are connected by a plurality of combination wirings. Further, the output terminal r of the transformer is connected between the main coil L2 and the exciting coil L3 of the circuit, and the output terminal t is connected between the main coil L6 and the exciting coil L7, and the zero-phase input terminal N is connected. The output terminal n is mutually connected.

A voltage sensor (not shown) for detecting an input voltage is incorporated in a board (not shown), and one terminal is connected to the input terminals of the main coils L1 and L5, and the other terminal is connected to the other. The terminal of was provided between each coil,
Each thyristor (1, 2, 3, 4, 5, 6, 7,
8) connected to the thyristor (1, 2,
3, 4, 5, 6, 7, 8) are turned on and off by an output signal sent by the voltage value detected by the voltage sensor, and each main coil L1, L2, L5, L6 in the circuit is turned on and off.
Also, the output voltage is autonomously adjusted by controlling the combination of the exciting coils L3, L4, L7 and L8.

Each of these thyristors (1, 2, 3, 4,
As shown in FIG. 1, the thyristor (1) is arranged between the main coil L6 and the exciting coil L3, and the thyristor (2) is arranged between the main coil L2 and the exciting coil L7. ) Is between the main coil L2 and the exciting coil L3, and the thyristor (4) is between the main coil L6 and the exciting coil L7.
, The thyristor (5) is between the exciting coils L3 and L7, and the thyristor (6) is between the exciting coils L4 and L8.
The thyristor (7) is connected between the main coil L2 and the exciting coil L8, and the thyristor (8) is connected between the main coil L6 and the exciting coil L4.

As described above, the power saving transformer with the step-up / down same-voltage autonomous switching device is disclosed in Japanese Patent Application Laid-Open No. 8-1915 of the present applicant.
Japanese Unexamined Patent Publication No. 42-42 discloses in detail the technical content of being able to autonomously switch the output voltage with respect to the input voltage to the step-up, step-down, and step-down circuits uninterruptedly. The outline is that of the input voltage detected by the voltage sensor. The value controls the thyristors provided between the ends of each main coil and between each exciting coil, and the circuit switches autonomously so as not to fall below the arbitrarily set minimum voltage of the load side voltage. By repeating such switching, a voltage value within a certain set voltage range can be output regardless of whether the input voltage drops or rises, or regardless of the value of the input voltage.

In such a power-saving transformer with step-up / down same-voltage autonomous switching, a thyristor is damaged by providing a time-lag closing circuit on the output side of the main coil so that an inrush current from the outside does not flow into the voltage adjusting circuit. Can be prevented. Therefore, a specific example of the time difference closed circuit will be described below with reference to a circuit diagram.

FIG. 2 shows a delay circuit DL (10) and an electromagnetic contactor MC (11) on the output side of the main coil of a power saving transformer.
An example in which a time difference closing circuit in which (an electromagnetic switch, a magnet switch, etc.) is set is provided will be shown. When the power of the voltage-saving transformer is turned on, the electromagnetic contactors provided in the main coil and the excitation coil are cut off.When the power of the power receiving transformer is turned on in such a state, the main coil is energized and put into the through state. After that, the delay circuit operates, and after 1 to 2 seconds, the main coil side and the excitation side coil are connected to shut off the inrush current when the power receiving transformer is turned on and damage the voltage adjustment circuit of the power saving transformer. Is eliminated and sufficient safety can be secured.

[0012]

According to the present invention, it is needless to say that the output voltage can be lowered to reduce the power consumption to save power, and even if the input voltage drops or rises outside the range of the set voltage, it is autonomous. Since it is adjusted so that the voltage value within the set range is output, there is no influence on the load. Further, the present invention has an advantage that it can be easily implemented because the output voltage can be autonomously adjusted by simply switching the connection of the exciting coil. Then, by preventing the inrush current from the outside from flowing into the voltage adjusting circuit, the thyristor is not damaged and the safety can be sufficiently ensured.

[Brief description of drawings]

FIG. 1 is a schematic configuration circuit diagram of a power-saving transformer with a step-up / down same-voltage autonomous switching device of the present invention.

FIG. 2 is a schematic configuration circuit diagram of the present invention.

[Explanation of symbols]

L1, L2, L5, L6 Main coil L3, L4, L7, L8 Excitation coil 1-8 Thyristor 9 Single-phase inner iron core 10 Delay circuit DL 11 Electromagnetic contactor MC

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Claims (2)

(57) [Claims] 1. In a single-phase three-wire or two-wire single-winding coil type transformer, two sets of main coils connected to an input terminal are wound around a single-phase inner iron core in two circuit phases, and each of these circuits Between the ends of the main coil, a plurality of sets of exciting coils wound around the core and connected in series with each other are connected by a plurality of combination wires, and the voltage value of the voltage sensor connected to the input terminal is used. , A plurality of sets of thyristors that are turned on and off are provided between the ends and between the exciting coils,
By turning on or off each of these thyristors, one or more sets are connected or cut between the ends and each exciting coil, and a circuit for boosting, equalizing, or stepping down the output voltage with respect to the input voltage is uninterrupted. A protection circuit for a power-saving transformer with a lifting and lowering same voltage autonomous switching device, characterized in that a time difference closed circuit is provided on the output side of the main coil of the power-saving transformer with a lifting and lowering same voltage autonomous switching device. . 2. The protection circuit for a power-saving transformer with a step-up / down same-voltage autonomous switching device according to claim 1, wherein the time difference closing circuit provided on the output side of the main coil comprises a delay circuit and a switch.