JP2001008459A - Controller for elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of emergency DC power due to regenerated power by connecting a discharge resistor to a phase different from a phase to which emergency DC power is connected and absorbing the regenerated power of elevator regenerative running, when power is cut by the two systems of emergency DC power and the discharging resistor. SOLUTION: When a commercial power 1 is cut, a contact point 2 is opened, and a contact point 3 is closed. An emergency DC power (battery) 5 is applied to the AC side of a converter 8. Converter elements 8b and 8f are always set to an arc extinguishing state, and a converter element 8e is always set to be the arc extinguishing state. At power running, a converter element 8d is switched and chopper control is executed. At regenerative running, a converter element 8a is switched, and voltage drop chopper control is executed. Regenerated energy is supplied to the emergency DC power 5. When the current detection value of a converter 6 reaches a prescribed value, the switching of the converter element 8a is stopped, and a converter element 8c is switched, and regenerated energy is consumed by a discharge resistor 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter control for an elevator, and more particularly, to preventing an emergency DC power supply from deteriorating due to regenerative power when operating with an emergency DC power supply at the time of a power failure, and performing switching during the operation. The purpose is to minimize the number of converter elements.

[0002]

2. Description of the Related Art Conventionally, a technique related to converter control at the time of a power failure of an elevator is disclosed in, for example, Japanese Patent Laid-Open No. 61-2488.
No. 81, which is shown in FIG. 5 of this specification.
In FIG. 5, when the commercial power supply 1 is normal, the contact 2 is closed and the contact 2 is opened, and the commercial power supply 1 is applied to the AC side of the converter 8 through the reactor 7. The converter control circuit 14 outputs a converter control pulse based on the input from the current transformer 6 and the transformer 4 to operate the converter 8,
The commercial power supply 1 is converted to DC and smoothed by the capacitor 9.
The DC power source smoothed by the capacitor 9 is applied to the DC side of the inverter 10, and is converted by the inverter 10 controlled by the inverter control circuit 15 into an AC power source with a variable voltage and a variable frequency. The inverter control circuit 15 includes the current transformer 1
1 and the input of a speed detector 13 for detecting the rotation of the motor 12, the voltage and frequency of the AC power supply are adjusted, and the motor 12 is driven.

Next, at the time of a power failure, the contact 2 is opened and the contact 3
Is closed, and the emergency DC power supply 5 is applied to the AC side of the converter 8. Converter control circuit 14 first ignites converter element 8e and stores the energy of DC power supply 5 in reactors 7b and 7c. Next, the converter element 8e
Is extinguished, and the energy stored in the reactors 7b and 7c is supplied to the capacitor 9. Such control is called step-up chopper control, and the voltage of the capacitor 9 can be made higher than the voltage of the DC power supply 5 and supplied to the inverter 10.

[0004]

The prior art does not take into account the degradation that can occur during elevator regenerative operation, that is, when the emergency DC power supply 5 is charged, and also specifically describes the converter element chopper operation during regeneration. Not stated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and realizes a converter circuit having a function of protecting an emergency DC power supply during a power failure, particularly during an elevator regenerative operation, with a simple circuit configuration and switching control. It is.

[0006]

According to one aspect of the present invention, an elevator control apparatus has a configuration in which a resistor is connected to a phase different from a phase to which an emergency DC power supply is connected, and a regenerative operation of an elevator regenerative operation at the time of a power failure is performed. Power is absorbed by two systems, a DC power supply and a discharge resistor. In another aspect of the present invention, the boost chopper operation during the elevator power running operation and the chopper operation during the regenerative operation are realized with a minimum number of switching elements.

[0007]

FIG. 1 is a circuit diagram showing an embodiment of the present invention. In FIG. 1, when the commercial power supply 1 is normal, the contact 2 is closed and the contact 3 is opened, and the commercial power supply 1 is applied to the AC side of the converter 8 through the reactor 7. The converter control circuit 14 outputs a well-known converter control pulse in response to inputs from the current transformer 6 and the transformer 4 to operate the converter 8, converts the commercial power supply 1 to DC, smoothes it with the capacitor 9, and 10 to the DC side. The inverter control circuit 15 includes the current transformer 11 and the motor 1
In response to the input of the detector 13 for detecting the rotation of the motor 2, a well-known inverter control pulse is output to operate the inverter 10, and the DC power stored in the capacitor 9 is converted into a variable voltage and a variable frequency AC power. 12 is driven.

At the time of power failure, the contact 2 is opened and the contact 3 is closed to apply the emergency DC power supply 5 to the AC side of the converter 8. The converter control circuit 14 first disconnects the converter elements 8b and 8f from the converter control pulse output so as to be always in an extinguishing state, and also disconnects the converter element 8e from the converter control pulse output and always in an ignition state. Here, during elevator power running operation, ie, the emergency DC power supply 5
When power is supplied to the capacitor 9 from the converter, the converter control circuit 14 switches the converter element 8d to perform chopper control.

Now, when the converter element 8d fires,
Emergency DC power supply 5-contact 3a-reactor 7a-converter element 8d-converter element 8e-reactor 7b-
Energy is stored in the reactors 7a and 7b by a closed circuit of the contact 3b. Next, when the converter element 8d is extinguished, the emergency DC power supply 5 and the reactor 7a are closed in a closed circuit of the emergency DC power supply 5-contact 3a-reactor 7a-converter element 8a-capacitor 9-converter element 8e-reactor 7b-contact 3b. , 7 b are supplied to the capacitor 9. By performing this switching operation quickly, a boost chopper that can supply a voltage higher than the voltage of the emergency DC power supply 5 to the capacitor 9 is obtained. FIG. 2 shows an equivalent circuit in this control state. Those having the same symbols as those in FIG.
The same circuit elements are shown.

Next, during the elevator regenerative operation, that is, when returning power from the capacitor 9 to the side of the emergency DC power supply 5, the converter control circuit 14 switches the converter element 8a or 8c to perform chopper control. Now, when converter element 8a is fired, capacitor 9—converter element 8a—reactor 7a—contact 3
a—Emergency DC power supply 5—Contact 3b—Reactor 7b—Converter element 8e charges emergency DC power supply 5 with a closed circuit, and stores energy in reactors 7a and 7b. Next, when the converter element 8a is extinguished, the reactor 7a is closed in a closed circuit of the reactor 7a, the contact 3a, the emergency DC power supply 5, the contact 3b, the reactor 7b, and the converter element 8e.
The energy of a and 7b is supplied to the emergency DC power supply 5. By performing this switching operation quickly, a step-down chopper can be supplied from the capacitor 9 to the emergency DC power supply. FIG. 3 shows an equivalent circuit in this control state. Here, the emergency DC power supply 5 often uses a battery, and the battery generally has a lower charge current withstand capability than the discharge current withstand capability. For this reason, when the regenerative energy of the elevator is large, the battery is in a quick charge state and may be deteriorated. Therefore, the converter control circuit 14 is provided with a function of stopping the switching of the converter element 8a and switching the converter element 8c when the current value of the current transformer 6 reaches a predetermined value. Now, when converter element 8c is fired, capacitor 9-converter element 8c
-Reactor 7c-contact 3c-discharge resistor 17-contact 3b
-Reactor 7b- Energy is stored in the reactors 7a and 7b in a closed circuit of the converter element 8e, and energy is consumed by the discharge resistor 17.

Next, when the converter element 8c is extinguished, the reactor 7c-contact 3c-discharge resistor 17-contact 3b-reactor 7b-converter element 8e-converter element 8
The energy of the reactors 7c and 7b is consumed by the discharge resistor 17 in the closed circuit of f. FIG. 4 shows an equivalent circuit in this control state. In the present embodiment, the switching periods of the converter elements 8a and 8c are separated to minimize the number of switching elements, but switching may be performed during the same period.

As described above, a converter circuit having a simple circuit configuration and having a function of protecting an emergency DC power supply during an elevator regenerative operation and minimizing switching converter elements is realized.

[0013]

According to the present invention, the converter control at the time of a power failure with the protection function of the emergency DC power supply can be realized by the switching operation with the minimum number of converter elements.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram in one operation state in one embodiment of the present invention.

FIG. 3 is an equivalent circuit diagram in one operation state in one embodiment of the present invention.

FIG. 4 is an equivalent circuit diagram in one operation state in one embodiment of the present invention.

FIG. 5 is a circuit diagram showing a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Commercial power supply, 2, 3 ... Contactor, 4 ... Transformer, 5 ... Emergency DC power supply, 6 ... Current transformer, 7 ... Reactor, 8 ... Converter, 9 ... Capacitor, 10 ... Inverter, 11 ... Current transformer , 12 ... motor, 13 ... speed detector, 14 ... converter control circuit, 15 ... inverter control circuit.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H02M 7/5387 H02M 7/5387 Z 5H576 7/797 7/797 H02P 5/41 302 H02P 5/41 302N 302J (72) Inventor Shunsuke Mine 1070 Ma, Hitachinaka City, Ibaraki Prefecture Inside the Mito Plant of Hitachi, Ltd. (72) Inventor Kaoru Yoshida 1-6-6 Kanda Nishikicho, Chiyoda-ku, Tokyo Reference) 3F002 AA04 EA08 GA03 3F304 CA05 EC03 EC04 5G015 GA02 GA11 HA03 HA15 JA05 JA15 JA27 JA32 JA35 JA53 JA55 5H006 AA02 BB01 BB05 CA01 CA07 CA12 CA13 CB01 CB08 CB09 CC01 CC05 DA02 DA04 DB01 DC02 DC05 FA01 FA02 ACB CB09 A01CB CC12 CC23 DA05 DA06 DB01 DC02 DC05 DC07 EA02 FA01 FA13 FA20 5H576 AA07 BB06 BB10 CC04 CC05 DD02 DD 04 EE09 EE21 HA04 HA10 HB02 HB10 MM13

Claims (2)

[Claims] A converter for converting commercial power to direct current;
A capacitor for smoothing the DC, an inverter for converting the smoothed DC power into AC, an electric motor driven by an AC power output from the inverter, and an AC motor connected to the AC side of the converter when the commercial power is cut off In an elevator equipped with an emergency DC power supply, a converter control circuit is provided for controlling the converter to perform AC / DC conversion when the commercial power supply is normal, and for chopper controlling the converter when the commercial power supply is interrupted, from the emergency DC power supply to the smoothing capacitor side. A converter control method wherein both a powering chopper control for transmitting power and a regenerative chopper control for transmitting power from the smoothing capacitor to the emergency DC power supply are realized by a single switching operation of a specific converter element. 2. The converter circuit according to claim 1, further comprising a regenerative power discharging circuit for suppressing an amount of regenerative current to said emergency DC power supply during regenerative operation of the elevator and preventing deterioration of the emergency DC power supply. A converter circuit characterized by the above.