JPH0236511B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a control device for an AC elevator.

[Prior art]

In recent years, inverters have come to be used to control elevator driving machines for purposes such as reducing power consumption. A specific example is shown in FIG.

In this Figure 1, 1 is a three-phase AC commercial power supply;
2 is an NFB, 3 is a normally open contact of a contactor that is excited when the elevator is running, and 4 is a converter that converts three-phase AC voltage into DC voltage.
is connected to a three-phase AC commercial power supply 1 via an NFB 2 and a normally open contact 3.

The output of the converter 4 is smoothed by a capacitor 5, and a DC voltage is applied to an inverter 6. The inverter 6 converts this DC voltage into a variable voltage, variable frequency three-phase AC voltage, and its output is used by an induction motor 7 for driving the elevator.
We are trying to supply it to

Further, a resistor 8 and the collector and emitter of a transistor 9 are connected in series between the input terminals of the inverter 6. This resistor 8 and transistor 9 are for consuming regenerated power from the induction motor 7 for driving the elevator.

The transistor in the inverter 6 and the transistor 9 for regenerative power consumption are controlled by a control circuit 10. Power is supplied to the control circuit 10 from the three-phase AC commercial power supply 1 via the three-phase transformer 11 and NFB2.

Further, the input end of a rectifier 12 is connected between the NFB 2 and the common contact 3, and the rectifier 12
The output terminal of is connected between the output terminals of converter 4 via resistor 13.

The rectifier 12 and resistor 13 are used to charge the capacitor 5 to a predetermined voltage in advance in order to suppress the rush current when the normally open contact 3 is turned on.

In addition, as a power supply for the control circuit 10, since multiple DC voltages with low ripple and relatively large current capacity are generally required, a three-phase transformer 11 is used, and three-phase AC voltage obtained from each secondary winding of the three-phase transformer 11 is used. The voltage is three-phase full-wave rectified to obtain multiple DC voltages.

When three-phase AC commercial power supply 1 is secured,
With the configuration shown in FIG. 1, AC power from the three-phase AC commercial power supply 1 is applied to the converter 4 through the NFB 2 and the normally open contact 3, and the converter 4 converts this AC power into DC power, and after smoothing it with the capacitor 5, Add to inverter 6.

Thereby, the inverter 6 generates an output of frequency and voltage according to the output of the control circuit 10, and controls the rotation speed and torque of the induction motor 7 for driving the elevator. Further, when electric power is regenerated from the elevator driving induction motor 7, the control circuit 10 detects this, turns on the transistor 9, and causes the resistor 8 to consume the regenerated electric power.

However, even when an elevator is installed, it is necessary to operate it to install equipment in the hoistway and landing area, but the three-phase AC commercial power supply 1 is generally not installed at the time of installation, so the configuration shown in Figure 1 is In order to operate the elevator with the control device, it was necessary to prepare a three-phase alternating current generator as a temporary power source, which caused problems in terms of arrangement costs and time.

[Summary of the invention]

This invention was made in order to eliminate the above-mentioned conventional drawbacks, and instead of preparing a three-phase AC temporary power source, a single-phase power source that is necessarily prepared as a power source for a welding machine at the time of installation can be used to operate an elevator at the time of installation. The present invention proposes a control system for an AC elevator that can perform the following operations.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the control device for an AC elevator according to the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing the configuration of one embodiment. In FIG. 2, in order to avoid duplication, parts that are the same as those in FIG. 1 are given the same reference numerals and their explanations are omitted, and parts that are different from those in FIG. 1 will be mainly described.

As is clear from comparing FIG. 2 with FIG. 1, in FIG.
The parts shown below have been added. That is, 1
4 is a single-phase AC power supply, and this single-phase AC power supply 14
is connected to NFB2 via NFB15 for single-phase AC power supply.
and the normally open contact 3 and the input end of the rectifier 12.

In addition, an inverter 1 is connected to the output terminal of the converter 4.
6 input terminals are connected. The inverter 16 converts the output of the converter 4 or the DC voltage of the rectifier 12 into a three-phase AC voltage, and this three-phase AC voltage is supplied to the control circuit 10 via the three-phase transformer 11. The other configurations are the same as in FIG. 1.

Next, the operation of the AC elevator control device of the present invention configured as described above will be explained.
When three-phase AC commercial power supply 1 is secured,
NFB15 is cut off and three-phase transformer 11
Since a three-phase AC voltage is applied to the inverter 16, its operation is the same as that shown in FIG.

On the other hand, if the three-phase AC commercial power supply 1 is not secured, the NFB 15 is turned on and power is supplied from the single-phase AC power supply 14. This single-phase AC voltage is applied to a converter 4 via a normally open contact 3, where it is converted to a DC voltage, smoothed by a capacitor 5, and applied to an inverter 6.

This smoothed DC voltage is also applied to the inverter 16, and the inverter 16 applies its output to the three-phase transformer 11 of the control circuit 10 as a three-phase AC voltage, thereby operating the control circuit 10.

The inverter 6 and the transistor 9 for regenerative power consumption operate according to the output of the control circuit 10,
Controls elevator operation.

According to the configuration shown in FIG. 2, the elevator can be operated at the time of installation using the single-phase AC power source 14 prepared as a power source for the welding machine at the time of installation, without having to prepare a three-phase AC temporary power source. Can be done.

FIG. 3 is a block diagram showing the structure of another embodiment of the control device for an AC elevator according to the present invention. In this FIG. 3, reference numeral 17 is added to the configuration of FIG. 2.
The following sections have been newly added.

In other words, 17 is a battery for supplying power for driving the elevator during a power outage, and 18 is a battery for the battery.
NFB, 19 is a normally open contact of a contactor that is energized when the elevator is running when operating the elevator with battery power; 20 is a capacitor 5 connected in advance to suppress the inrush current when the normally open contact 19 is closed; This is a diode to keep the voltage charged.

The battery 17 is connected to the output terminal of the converter 4 and the input terminal of the inverter 16 via the NFB 18 and the normally open contact 19, and from the connection point between the NFB 18 and the normally open contact 19, the output of the rectifier 12 is passed through the diode 20. connected to the end.

Next, the operation of the embodiment of FIG. 3 constructed as above will be explained. If the single-phase AC power supply 14 is not available and the three-phase AC commercial power supply 1 is out of power, DC voltage is supplied from the battery 17 to the inverter 6 and the inverter 16, making it possible to carry out a rescue operation in the event of a power outage.

That is, by simply adding the battery 17 and simple equipment to the configuration shown in FIG. 2, rescue operation during a power outage can be easily performed.

〔Effect of the invention〕

As explained above, according to the AC elevator control device of the present invention, a second inverter is provided to convert the voltage on the DC side of the inverter into a three-phase AC voltage, and its output is used as a power source for the control circuit of the main inverter. Therefore, there is no need to prepare a three-phase AC temporary power source during installation, and the elevator can be operated with a single-phase power source prepared as a power source for the welding machine. Additionally, rescue operations during power outages can be easily performed by adding a battery.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional AC elevator control device, FIG. 2 is a block diagram showing the configuration of an embodiment of the AC elevator control device of the present invention, and FIG. 3 is a block diagram of the AC elevator control device of the present invention. FIG. 2 is a block diagram showing the configuration of another embodiment of the invention. 1... Three-phase AC commercial power supply, 4... Converter, 6,
16... Inverter, 7... Elevator driving induction motor, 9... Transistor, 10... Control circuit, 11
...three-phase transformer, 12...rectifier, 14...single-phase AC power supply, 17...battery. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A converter that uses a three-phase AC power source and a single-phase AC power source as an input source, receives either one of the input sources, converts it into DC power, and outputs the converted DC power; a first inverter that converts direct current into variable frequency alternating current power and outputs it; an elevator driving induction motor driven by the alternating current power output from the first inverter; and a second inverter that converts the DC voltage output from the converter into AC and supplies power to the control circuit. A control circuit for an AC elevator, comprising: