KR900005294Y1 - Saving devices at interruption of electric power of elevator - Google Patents

Abstract

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Description

Blackout Rescue Device of Elevator

1 is a main circuit diagram of an embodiment of the present invention.

2 is a circuit diagram of an elevator control apparatus using an inverter of a conventional voltage type variable voltage and variable frequency control method.

3 is a circuit diagram of a control device of an inverter of a conventional voltage type variable voltage and variable frequency control method.

* Explanation of symbols for main parts of the drawings

2: converter 5: inverter

6: induction motor 8: charging circuit

9: battery 10, 12: contactor

TR: Transistor D ₁ , D ₁₁ , D ₁₂ : Diode

The present invention relates to a rescue device in case of power failure of an elevator, so that a rescue circuit can be attached in case of power failure even when a current inverter is used.

In recent years, with the development of control technology, the VVVF (variable voltage, variable frequency) control method has been adopted in the elevator control method. There are two basic types of this VVVF: voltage type and current type.

Among them, the former voltage type is configured as shown in FIG.

FIG. 2 shows an example in which a rescue circuit at the time of power failure is applied to the conventional voltage type VVVF. R, S and T in FIG. 2 are each phase of a three-phase AC power supply not shown.

Each of R, S, and T is connected to the input terminal of the converters 2 and 3 via the contact group 1 of the contactor.

The converters 2 and 3 each constitute a three-phase land circuit as a thyristor SCR, and the converters 2 and 3 are connected in parallel.

The smoothing capacitor 4 is connected between the output terminals of the converters 2 and 3 so as to smooth the DC voltage obtained by rectifying the three-phase AC power in the converter 2 with the smoothing capacitor 4.

The converter 3 allows the induction motor 6 to operate at the time of regeneration.

The output voltage of the converter 2 is applied to the inverter 5, the inverter 5 is composed of a transistor TR and a diode D, and the diode D is disposed between the emitter and the collector of each transistor TR. It is connected and it is comprised integrally.

The inverter 5 converts the output voltage of the converter 2 into a three-phase alternating voltage of a predetermined frequency and a predetermined voltage to drive the induction motor 6.

An elevator (not shown) is driven by this induction motor 6.

The input terminal of the converter 2 is connected to the input terminal of the charging circuit 8 via the transformer 7.

The battery 9 is charged by the output of the charging circuit 8.

The positive electrode of the battery 9 is connected to the output terminal on the positive side of the converters 2 and 3 via the contactor 10 of the contactor, and the negative electrode of the battery 9 is connected to the converter 2. (3) is connected to the output terminal of the (-) axis.

The battery 9 is a power source of the rescue circuit at the time of power failure.

The following operation will be described.

In the normal power supply, the contact group 1 of the contactor is closed, and the contact 10 of the contactor is open.

By closing the contact group 1 of the contactor, the voltages of the respective phases R, S and T of the three-phase AC power supply are applied to the converter 2 and converted into DC voltages.

This DC voltage is smoothed by the smoothing capacitor 4 and applied to the inverter 5.

In this inverter 5, it is converted into an alternating current of an arbitrary frequency and an arbitrary voltage using a pulse width modulation technique, and supplied to the induction motor 6.

As a result, the flow motor 6 is driven to drive the elevator car.

Such a description of the VVVF control is well known and therefore not described herein.

Now, for example, if the converter 2 is used in the reverse direction of the ascending direction, the converter 3 is used for the regeneration.

Since the voltage polarity at both ends of the smoothing capacitor 2 is constant, the current direction is reversed in accordance with retrograde and regeneration.

By the way, at the time of power failure, the contact group 1 at the time of contact is opened and the contactor 10 is closed.

At this time, the power of the battery 9 is connected to the DC circuit through the contactor 10 is converted by the inverter 5 into an alternating voltage of variable voltage, variable frequency.

Other operations are the same as in normal power supply.

As the voltage polarity of the linearity circuit shown in FIG. 2 constantly performs four-quadrant operation of retrograde sacrificial current, the current direction is reversed.

On the contrary, in the voltage type, the current direction of the DC circuit is constant, and the voltage polarity is reversed as the quadrant operation is performed. FIG. 3 shows a current type circuit, and the same parts as in FIG. 2 in FIG. 3 are denoted by the same reference numerals. The voltage of each phase of the three-phase alternating voltage is applied to the input terminal of the converter 2 through the contact group 1 of the contactor, and the converter 2 is a diode in a circuit in which the transistor TR and the diode D are paralleled. A three-phase branch circuit is formed by connecting (D ₁ ) in series.

The output of this converter 2 is supplied to the inverter 5 via the reactor 11.

The inverter 5 is constituted by a transistor (TR) and a diode also (D) (D ₁₎ is constructed as in the converter (2).

The inverter 5 is configured to drive the induction motor 6 by converting the DC output of the converter 2 into alternating frequency of variable frequency and variable voltage.

3 differs from FIG. 2 in that the diode D ₁ is connected to the transistor TR of the converter 2 and the inverter 3, respectively, so that the current direction is constant and the voltage polarity of the DC circuit is reversed according to the reversal of regeneration. This is to be reversed.

In the case of the current inverter shown in FIG. 3, there is no element with a shorter lifetime (electrolytic capacitor is shorter) than the case of the voltage inverter shown in FIG.

In the case of voltage inverters, 18 thyristors and low transistors are needed, while in the case of current inverters, 12 (the diodes are inexpensive and not considered) are sufficient. It is expected to be.

However, in the case of the current type inverter, there is a drawback that the battery cannot be connected to the DC circuit at the time of power failure because the voltage polarity changes.

This invention has been devised to solve such a problem, and has a simple configuration, and has an object of obtaining an electrostatic discharge device of an elevator which can attach a rescue circuit to a current type inverter in the event of a power failure.

The electrostatic discharge device of the elevator of the present invention is provided with a reverse flow prevention series diode connected between upper and lower arms of a ground connected transistor constituting an inverter, and a contactor connected in parallel to the series circuit of the series connected diode.

In this design, the contactor is closed at the time of power failure to short-circuit the series circuit of the diode, and the battery is closed to short-circuit the series circuit of the diode and the batteries are connected in series.

Next, an embodiment of this invention will be described with reference to the drawings.

1 is a circuit diagram of one embodiment of this invention.

In Fig. 1, the same parts as those in Figs. 2 and 3 are denoted by the same reference numerals.

In FIG. 1, the charging circuit 8, the battery 9, the contacts 10 and 12 of the contactor, and the diodes D ₁₁ and D ₁₂ are newly added to the circuit configuration of FIG.

In other words, although not shown in FIG. 1, an AC voltage is applied to the converter 2 through the contact root 1 of the contactor indicated in FIG. ) Is converted into direct current and then applied to inverter 5 through reactor 11, and converter 2 uses the one shown in FIG.

The inverter 5 converts this direct current into an alternating current of variable frequency and variable voltage to drive the induction motor 6.

In particular, the inverter 5 is connected to the three-phase ground as the transistor TR, and the backflow prevention diodes D ₁₁ and D ₁₂ are connected in series between the upper and lower arms of each transistor TR to form a series circuit.

The connection point of each diode D ₁₁ and D ₁₂ is connected to the induction motor 6.

The contact 12 of the contactor is connected in parallel to the series circuit of the diodes D ₁ and D ₁₂ , respectively.

The contacts 10 and 12 of this contactor are simultaneously opened at the time of the empty normal power supply and closed at the same time in the case of power failure, and constitute the first switching means and the second switching means, respectively.

The contactor having these contacts is controlled by the presence or absence of the output of the current detector provided in at least one of R, S, and T of the three-phase AC power supply.

When there is an output of the current detector, the power is judged normally and the contactor is excited, and their contacts 10, 12 are opened. On the contrary, when there is no output of the current detector, the power is judged to be abnormal and the contactor is deemed a contact. 10) 12 is closed.

The output terminal of the charging circuit 8 is connected to the positive (+) (-) anode of the battery 9.

This battery 9 serves as a power source for the rescue circuit of an elevator during a power failure.

The negative electrode of the battery 9 is connected to the output terminal on the negative side of the converter 2 and is connected to the positive side of the battery 9, that is, to the reactor 11 and the positive side of the inverter 5. Is connected between.

With this configuration, at the time of power failure, the contactor contacts 10 and 12 are simultaneously closed and the battery 9 is connected between the DC circuit, that is, between the input terminals of the inverter 5.

At the same time, each series circuit of diodes D ₁₁ and D ₁₂ is short-circuited by the contacts of the contactor 12.

For this reason, the inverter 5 is switched from the current type to the voltage type, as shown in FIG. 2, and can perform the rescue operation using the battery 9.

This invention inserts a series circuit in which a backflow prevention diode is connected in series between the upper and lower arms of each ground-connected transistor constituting the inverter as described above, and connects the contactor of the contactor which is closed in case of power failure in parallel to the DC circuit. By short-circuiting the series circuit of the diode to switch the inverter from the current type inverter to the voltage type inverter, there is an effect that can be rescued in case of power failure by the current type inverter with a simple configuration.

Claims (6)

In an elevator having an electrostatic discharge device for operating an elevator by an emergency power supply when there is an abnormality in an AC power source, a converter (2) for converting the AC power of the AC power source into a direct current (DC) and the converter (2) connected to the direct current As an inverter for converting into alternating current, a plurality of arms formed of a pair of transistors TR connected in series and a pair of diodes D ₁₁ (D ₁₂ ) inserted and connected between the transistors in series with the same polarity as the series circuit of the transistors. A parallel circuit is constructed by connecting in parallel, and each intermediate connection point of the pair of diodes D ₁₁ and D ₁₂ is connected to the elevator driving motor 6, and supplies alternating current of variable voltage and variable frequency to the motor. An inverter 5, an emergency DC power supply 9 connected to a DC input unit of the inverter 5, and an emergency connection between the emergency DC power supply and the inverter 5, A first switching male end 10 for connecting the emergency DC power source 9 to the inverter 5 when the AC power source is in an open state; It is connected to a pair of diodes (D ₁₁ ) (D ₁₂ ) of each arm in parallel, and the AC power supply is in an open state when it is normal, and the pair of diodes is valid. When the AC power supply is abnormal, it is closed. And a second switching means (12) for forming a circuit for bypassing the pair of diodes and for making the DC voltage polarity of the inverter constant. The diode D is connected in parallel between the emitters and the collectors of the pair of transistors TR so that the polarities of the transistors are opposite to each other. Is connected between the pair of diodes (D ₁₁ ) (D ₁₂ ) and the diodes (B) connected in parallel with each other in reverse polarity to the pair of transistors (TR), and the pair of diodes (D ₁₁ ) ( An elevator electrostatic discharge device in parallel with respect to D ₁₂ ). 2. The electrostatic discharge device of an elevator according to claim 1, wherein the first switching means (10) and the second switching means (12) switch to a closed state at the same time when the AC voltage becomes an abnormal state. The elevator of claim 1, wherein the first switching means (10) is inserted and connected between a (+) side terminal of the emergency DC power supply and a (+) side terminal of the DC side of the inverter (5). Electrostatic discharge device. 2. The electrostatic discharge of an elevator according to claim 1, wherein said first and second switching means (10) (12) are constituted by a contactor, said contactor being controlled by a direct current detector installed to detect a state of said alternating current power supply. Device. The pair of normal closing contacts (10) (12), which are closed when the contactor is in an unexcited state, are inserted between the emergency DC power supply (9) and the inverter (5). An electrostatic rescue device for elevators connected in parallel to a diode.