JP2839638B2 - Elevator control device - Google Patents

Description

Description: Object of the Invention (Industrial application field) The present invention relates to an elevator control device that controls an elevator drive motor by an inverter, and particularly relates to a connection position of a DC power supply for emergency movement. About improvement.

(Prior Art) In recent years, as a rescue operation device at the time of a power failure, a system in which the main circuit of the main control device is used as it is without using a special control device therefor has been often used.

FIG. 4 shows a main circuit configuration of a conventional control device of this kind disclosed in Japanese Patent Publication No. Sho 63-26070. In FIG. 1, a three-phase full-wave rectifier circuit 2 as a converter is connected to a three-phase AC power supply R, S, T via a circuit breaker 1. Connected to the DC side of the three-phase full-wave rectifier circuit 2 is a smoothing capacitor 3 for smoothing a pulsating flow, and an inverter 4 for converting the smoothed DC to a variable voltage and a variable frequency AC. The AC output is supplied to an induction motor 5 for driving the elevator. A storage battery 6 for emergency operation at the time of a power failure or the like is connected to the DC side of the three-phase full-wave rectifier circuit 2 via a contactor 7 as a switch.

Therefore, when the contactor 7 is closed during an emergency operation during a power failure, the smoothing capacitor 3 is charged by the storage battery 6 and DC power is supplied to the inverter 4.

In this device, a storage battery 6 is connected to the DC side of the three-phase full-wave rectifier circuit 2 in the concept of replacing a DC voltage generation circuit, but there is also a concept of replacing an AC power supply.

FIG. 5 shows a configuration example based on this concept, in which a storage battery 6 is connected via a contactor 7 between two lines on the AC side of the three-phase full-wave rectifier circuit 2. That is, when the contactor 7 is closed during an emergency operation, the smoothing capacitor 3 is charged and the DC power is supplied to the inverter 4 via the three-phase full-wave rectifier circuit 2.

On the other hand, the control device having the smoothing capacitor 3 is provided with a preliminary charging circuit so that an excessive rush current does not flow when the power is turned on regardless of whether the emergency storage battery 6 is connected.

FIG. 6 shows an example of the configuration, in which a connector 9 is provided on the AC power supply side of the three-phase full-wave rectifier circuit 2 while the three-phase full-wave rectifier circuit 2
A pre-charging circuit is provided in the main circuit system that connects the current limiting resistor 8 and the contactor 10 in parallel. Further, a series connection circuit of a normally closed contact 9B of the contactor 9, a normally closed contact 10B of the contactor 10, and a discharge resistor 11 is connected in parallel to the smoothing capacitor 3. This puts the smoothing capacitor 3 into a discharged state with both the contactors 9 and 10 open as shown. During emergency movement, contactor 10
Is closed, the contactor 9 is closed, and the smoothing capacitor 3 is charged through the current limiting resistor 8. Then, after a predetermined time has passed since the closing of the contactor 9 or when the voltage across the smoothing capacitor 3 has reached a predetermined level, the contactor 10 is closed to supply power to the inverter 4. In this case, Joule loss due to the current limiting resistor 8 is prevented.

FIG. 7 shows another configuration example, in which a contactor 9 is provided on the AC side of the three-phase full-wave rectifier circuit 2, and three contactors 9 connecting the contactor 9 and the three-phase full-wave rectifier circuit 2 are provided. Current limiting resistors 8 are provided on two of the power supply lines, respectively. A contactor 10 is connected between the AC power supply side of the contactor 9 and the AC input terminal of the three-phase full-wave rectifier circuit 2. Furthermore, a series connection circuit of the normally closed contact 9B of the contactor 9, the normally closed contact 10B of the contactor 10, and the discharge resistor 11 is connected to the smoothing capacitor 3 in parallel. Also in this case, the contactor 9 is closed with the contactor 10 opened, and the smoothing capacitor 3 is charged via the current limiting resistor 8. Thereafter, the contactor 10 is closed to prevent Joule loss due to the current limiting resistor 8.

6 and 7 both open the contactors 9 and 10 when a power failure occurs, and immediately discharge the smoothing capacitor 3.

[Problems to be solved by the invention]

When the storage battery 6 is connected in an emergency such as a power failure, the storage battery 6 is connected to both ends of the smoothing capacitor 3 in FIG. 4, and is connected to the AC terminal of the three-phase full-wave rectifier circuit 2 in FIG. When this storage battery connection method is applied to the control device shown in FIG. 6 having a pre-charging circuit, an inrush current proportional to the output voltage of the storage battery 6 and the capacitance of the smoothing capacitor 3 flows to degrade the characteristics of the smoothing capacitor 3. There was something. Also, the seventh
When applied to the control device shown in the figure, the rectifying element constituting the three-phase full-wave rectifier circuit 2 may be broken.

The present invention has been made in order to solve the above-mentioned problems, and it is an elevator that can suppress an inrush current when a DC power supply is connected, thereby preventing deterioration in characteristics of a smoothing capacitor and destruction of a rectifying element. The purpose is to obtain a control device.

[Configuration of the invention]

(Means for Solving the Problems) According to the present invention, a smoothing capacitor and an inverter which exchanges smoothed DC into AC and supplies the AC to an elevator drive motor are connected to a DC side of a converter for rectifying an AC power supply voltage. In a control device for an elevator, a current limiting resistor connected to a charging path of a smoothing capacitor, a DC power supply connected to a main circuit system on an AC power supply side of the current limiting resistor, and a smoothing capacitor connected in parallel. First switching means having an normally open contact connected in series with the connection path of the DC power supply and a normally closed contact connected in series with the discharge resistor, and operating in an emergency, and a current limiting resistor It has a normally open contact connected in parallel to a normally closed contact connected in series to a discharge resistor,
And a second opening / closing means that operates later than the first opening / closing means.

(Operation) In the present invention, the DC power supply for operating in an emergency is connected to the main circuit system on the AC power supply side of the current limiting resistor, and the second DC power source is connected in parallel to the current limiting resistor. The normally open contact of the switching means is connected to a first path connected to the connection path of the DC power supply.
Since the closing operation is performed later than the normally open contact of the switching means, the inrush current can be suppressed even when a DC power supply is connected.

Further, since the connection circuit of the discharge resistor connected in parallel to the smoothing capacitor is opened by the normally open contact of the first switching means for connecting the DC power supply, the first switching means operates. Until the second opening / closing means operates, it is possible to prevent a situation in which a current flows through the discharge resistor to cause a power loss.

(Embodiment) FIG. 1 is a circuit diagram showing an embodiment of the present invention, in which the same reference numerals as in FIG. 6 denote the same elements. A three-phase full-wave rectifier circuit 2 is connected between a precharge circuit composed of a current limiting resistor 8 and a normally open contact of a contactor 10 as a second switching means (hereinafter simply referred to as a contactor 10). A normally open contact of a contactor 7 as a first switching means on the positive and negative power supply lines (hereinafter simply referred to as contactor 7).
And the normally closed contact 9B of the contactor 9, the normally closed contact 10B of the contactor 10, and the normally closed contact of the contactor 7 in the series connection circuit of the discharge resistor 11. 7B is connected in series, and this circuit is connected in parallel with the smoothing capacitor 3, which is different from FIG.

In FIG. 1, while the elevator is stopped, that is, while the contactors 7, 9 and 10 are open, the contacts 7B, 9B, 10B
The charge of the smoothing capacitor 3 is discharged by the series connection circuit of the discharge resistor 11.

Next, when the operation is started by the AC power supply, the contactor 9 is closed with the contactor 7 and the contactor 10 opened. At this time, the pulsating flow rectified by the three-phase full-wave rectifier circuit 2 flows into the smoothing capacitor 3 via the current limiting resistor 8, and the smoothed direct current is supplied to the inverter 4. In this case, the inrush current is suppressed low by the current limiting resistor 8. Thereafter, the contactor 10 is closed and the output of the three-phase full-wave rectifier circuit 2 is directly applied to the smoothing capacitor 3. Here, when a power failure occurs, the contactor 9 is opened, so that the electric charge of the smoothing capacitor 3 is discharged via the discharge resistor 11.

Next, when an emergency operation is performed by the storage battery 6, the contactor 7 is closed while the contactor 10 is open. At this time,
The output current of the storage battery 6 flows into the smoothing capacitor 3 via the current limiting resistor 8. Thereafter, the contactor 10 is closed after a certain period of time or when the voltage across the smoothing capacitor 3 exceeds a predetermined level. Therefore, the storage battery 6
In the case of operation with an AC power supply, the rush current can be suppressed similarly.

In the conventional control device in which the normally closed contact of the contactor 7 is not included in the circuit of the discharge resistor 11, while the contactor 7 is closed and then the contactor 10 is closed, the output from the storage battery 6 is not changed. The current is shunted to the smoothing capacitor 3 and the discharge resistor 11 to cause power loss. However, in this embodiment, since the circuit of the discharge resistor 11 is interrupted by the normally closed contact of the contactor 7, the power loss can be reduced to zero.

FIG. 2 is a circuit diagram showing another embodiment of the present invention.
In the figure, the same reference numerals as in FIG. 1 denote the same elements. In FIG. 1, the series connection circuit of the storage battery 6 and the contactor 7 is connected between the DC output power supply lines of the three-phase full-wave rectifier circuit 2; Connected between lines. In this case, although the output of the contactor 7 is supplied to the smoothing capacitor 3 and the inverter 4 via the three-phase full-wave rectifier circuit 2, the contactor 7
By closing the contactor 10 in the same manner as in the above embodiment, the rush current can be similarly reduced.

FIG. 3 is a circuit diagram showing another embodiment of the present invention, in which a pre-charge circuit including a current limiting resistor 8 and a contactor 10 is provided on the AC power supply side of the three-phase full-wave rectifier circuit 2. In this case, the series connection circuit of the storage battery 6 and the contactor 7 is connected to the AC power supply side of the current limiting resistor 8. Also in the case of such a configuration, the inrush current can be suppressed low as described above.

In each of the above embodiments, the case where the emergency operation is performed by the storage battery 6 has been described. However, it is needless to say that the present invention can be applied to a case where another DC power supply is used.

〔The invention's effect〕

As apparent from the above description, according to the present invention, the DC power supply for operating in an emergency is connected to the main circuit system on the AC power supply side of the current limiting resistor, and is connected in parallel with the current limiting resistor. The normally open contact of the connected second switching means is closed at a later timing than the normally open contact of the first switching means connected in series to the connection path of the DC power supply. The current can be kept low.

Also, since the connection circuit of the discharge resistor connected in parallel to the smoothing capacitor is opened by the normally open contact of the first opening / closing means, the second opening / closing means operates after the first opening / closing means operates. Until the operation, the situation in which a current flows through the discharge resistor and power loss occurs can be prevented.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing the configuration of one embodiment of the present invention, and FIG.
FIG. 3 is a circuit diagram showing a configuration of another embodiment, FIG. 3 is a circuit diagram showing a configuration of another embodiment, and FIGS. 4 to 7 show various configuration examples of a conventional elevator control device. FIG. DESCRIPTION OF SYMBOLS 1 ... Circuit breaker, 2 ... Three-phase full-wave rectifier circuit, 3 ... Smoothing capacitor, 4 ... Inverter, 5 ... Induction motor, 6 ...
... storage battery, 7, 9, 10 ... contactor, 8 ... current limiting resistor, 11 ...
... discharge resistors.

Claims (1)

(57) [Claims] An elevator control device comprising: a smoothing capacitor connected to a DC side of a converter for rectifying an AC power supply voltage; and an inverter for converting the smoothed DC to AC and supplying the AC to an elevator driving motor. A current limiting resistor connected to a charging path of the smoothing capacitor, a DC power supply connected to a main circuit system on an AC power supply side of the current limiting resistor, and a discharge resistor connected in parallel to the smoothing capacitor. A first switching means having an normally open contact connected in series to a connection path of the DC power supply and a normally closed contact connected in series to the discharge resistor and operating in an emergency, and being parallel to the current limiting resistor; And a second switching means having a normally open contact connected thereto and a normally closed contact connected in series to the discharge resistor, and operating at a later time than the first switching means. Elebe Other control devices.