JPS61102194A - Controller of drum winding type elevator - Google Patents

Abstract

PURPOSE:To eliminate regenerative power consumption resistor even when an inverter is used for a small-sized hoisting drum type elevator by DC-brake controlling at a downward operation time. CONSTITUTION:Since a downward relay contact 12a is closed at downward operation time, when it becomes Vs<Vp in response to a deviation between a speed command Vs and a speed feedback amount Vp, a calculator DP2 operates, the deviation output is input through a contact 12a to a DC brake controller DB, the transistor of an inverter INV of the prescribed phase preset by this circuit is fired to DC-brake control an induction motor IM. Thus, energy from an elevator side is all consumed in the motor IM, and the regenerative power consuming resistor can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a control device for a drum type elevator, and particularly to a control device suitable for controlling using an inverter.

[Background of the invention]

Conventional drum type elevators are low cost and space saving.
Although it was marketed for the purpose of increasing the number of cars, its control means were primary voltage control during acceleration and direct current braking during deceleration, just as in general crane elevators. What are the disadvantages of this method?

For example, as shown in Japanese Utility Model Application Publication No. 58-176851, a large number of contactors are required, making it difficult to downsize the control device, which is a key to space saving, which is one of the selling points. . Also, start.

Since the contactor opens and closes when the car is stopped, the noise may propagate to the car and cause problems. Furthermore, although there are many requests to make the power supply equipment in buildings as small as possible, there is also the problem that primary voltage control is inefficient at startup or shut down, requiring large power supply equipment.

[Purpose of the invention]

The present invention has been made in view of the above, and an object of the present invention is to provide an inexpensive and small control device for a drum-type elevator using an inverter.

[Summary of the invention]

The present invention utilizes the mechanical condition of the drum type elevator, in which the load is always heavy during upward operation and the load is always light during downward operation, and since it is always in a running state during upward operation, it also poses no problem as an inverter. However, if the frequency is controlled during descending operation, it will enter a regenerative state, and the processing of this regenerative energy becomes a problem.For example, the method of processing this regenerative energy is to switch only two of each transistor of the inverter. For example, this method was developed with a focus on the fact that direct current can be obtained as an output, and a frequency control means is used to control the frequency of the three-phase induction motor that uses the inverter to drive the winding drum hoist during upward operation, and a frequency control means for controlling the frequency of the three-phase induction motor that drives the winding drum hoist using the inverter during upward operation. The present invention is characterized in that it is configured to include a DC braking control means for performing DC braking control using the input of the three-phase induction motor as a DC current.

[Embodiments of the invention]

The present invention will be described in detail below with reference to the embodiments shown in FIGS. 1, 2, and 5, and FIGS. 3 and 4.

FIG. 1 is an overall configuration diagram showing one embodiment of a control device for a drum type elevator according to the present invention. In Figure 1, the ride and CAGE are connected to the conch hoist TMC via a rope L and a pulley P, and an induction motor IM and a speed detector PG are attached to the winder hoist TMC. The induction motor IM's phases U, V,
A control device CP according to the present invention is connected to W.

FIG. 2 is a block diagram showing an embodiment of the inside of the control device shown in FIG. In Figure 2, CON is a three-phase AC power supply R
, S, and T to direct current, and INV is a transistor inverter that converts the direct current from the converter section CON to alternating current with variable frequency and variable voltage.
It is connected to M.

On the other hand, the difference between the speed command v8 and the feedback amount V of the signal from the speed detector PG is calculated by a comparison calculation circuit OPI, and the feedback amount vP is added to output the frequency command f. During ascending operation, the ascending operation relay contact 11° is closed, and the frequency command f is input to the pulse width modulation circuit PWM in the inverter's arithmetic circuit LOGIC, and each transistor T of the inverter INV is
R31~TR5,.

The frequency of the induction motor IM is controlled by switching.

In addition, during descending operation, energy is transmitted from the elevator side to the induction motor IM, so if the induction motor IM is frequency controlled, the induction motor IMlPJ will be in the regenerative braking region. In order to reduce costs, direct current is obtained by switching two phases of the six transistors TRS□ to TR8 of the inverter INV, for example, transistors TR81 and TR8, and this direct current is applied to the induction motor IM. DC braking control is performed by applying DC braking control, and all the energy from the elevator side is consumed inside the induction motor IM, eliminating the need for a regenerative power consumption resistor6.In other words, during descending operation, the descending operation relay contact 12a is activated. Since the circuit is closed, the computing unit OP2 operates when v8<V, depending on the deviation between the speed command v,l and the speed feedback amount V,
Contact point 12. The deviation output is sent to the DC braking control circuit D via
In this circuit, the transistor of the inverter INV of the phase set in advance is ignited to start the induction motor I.
M is controlled by direct current braking.

Figures 3 and 4 are diagrams for explaining the principle of control by the inverter INV in Figure 2, Figure 3 is a diagram showing the relationship between frequency and AC voltage, and Figure 4 is a diagram showing the rotation of the induction motor IM. In the relationship diagram between number and torque, the AC voltage V must be approximately proportional to the 0 frequency f, which shows each voltage and two frequencies as parameters, as shown in Figure 3. Elements (transistors and thyristors)
As a control method, there is a known PWM control (pulse width variation!!il), and in FIG. It is configured to give Moreover, FIG. 4 shows a curve when inverter control is performed, and shows that the speed of the elevator can be controlled by changing the frequency.

As described above, according to the embodiments of the present invention, it is possible to control the descending operation of the drum type elevator at low cost and with high precision using an inverter device.

FIG. 5 is a block diagram corresponding to FIG. 2 showing another embodiment of the present invention, and the same parts as in FIG. 2 are designated by the same reference numerals, and their explanation will be omitted here. Note that illustration is omitted because the main circuit is slightly different and the others are the same. Figure 2 shows an inverter IN as a means of applying DC braking during descending operation.
Although a V transistor is used, in FIG. 5, means for controlling direct current braking is provided as a separate circuit. That is, the transistor TR87 for DC current control, the free-boiling diode FD during switching, and the DC braking contactor COT are connected to two phases of the induction motor IM as shown in the figure, and during descending operation, the speed feedback amount v, 〉When the speed command V becomes loud, DC braking control is performed to stop the elevator.
It is designed to control.

Figure 5 has more parts than Figure 2, which increases the cost, but Figure 2 has two parts for DC braking.
transistors, for example, transistors TR8, T
Although there is a problem that the usage rate of R3 becomes high and the thermal balance of the elements is destroyed, in FIG. 5, the thermal balance of each element can be maintained, so there is an advantage that reliability is improved.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to obtain a compact drum-type elevator using an inverter.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the control device for a drum elevator according to the present invention, FIG. 2 is a block diagram showing an embodiment of the inside of the control device of FIG. 1, FIG. Figure 4 is a diagram for explaining the principle of control by the inverter in Figure 2;
FIG. 5 is a block diagram corresponding to FIG. 2 showing another embodiment of the present invention. TMC: winding drum type hoist, IM: three-phase induction motor. CP...control device, CON...converter section, IN
V...Inverter, TRS, ~TR8,...Transistor, PG...Speed detector, OPI, CP2...
Comparison calculation circuit, 11. ...Rising operation relay contact, 12
．． ...Downward operation relay contact, PWM...Pulse width modulation circuit. DB...DC braking control circuit, COT...DC braking contactor, FD...freewheel diode.

Claims (1)

[Claims] 1. A car, a winding drum type hoist that drives the car via a rope, a three-phase induction motor that drives the hoist, and a frequency control for the three-phase induction motor. A control means comprising an inverter for controlling the frequency of the three-phase induction motor with the inverter during upward operation, and a frequency control means for controlling the frequency of the three-phase induction motor using the inverter during downward operation. 1. A control device for a drum-type elevator, comprising: DC braking control means for controlling DC braking as a direct current. 2. The winding drum type according to claim 1, wherein the DC braking control means comprises a DC braking control circuit that obtains DC by switching only two of the six transistors of the inverter during descending operation. Elevator control device. 3. The DC braking control means connects a DC current control transistor and a DC braking contactor between two phases of wiring from the inverter to the three-phase induction motor and the inverter, respectively, and connects the transistor and the DC braking contactor. Connecting a freewheel diode between the wiring connected to the contactor,
2. A control device for a drum-type elevator according to claim 1, wherein the control device is configured to perform DC braking control during descending operation.