JPH0485272A - Method and device for operating hydraulic elevator using inverter driving system - Google Patents

Abstract

PURPOSE:To perform saving of energy by switching an inverter power supply to a commercial power supply on the halfway of up-operation of an elevator and the commercial power supply to the inverter power supply at the time of fixed speed clown-operation. CONSTITUTION:In the case of a transfer from accelerative up-operation to fixed speed up-operation after starting up-operation of an elevator and in the case of a transfer from accelerative down-operation to fixed speed down- operation after starting down-operation, a power supply of an electric motor 2 is switched from an inverter power supply 5 to a commercial power supply (frequency 50Hz or 60Hz)4. In the case of a transfer from fixed speed up- operation to decelerative up-operation and in the case of a transfer from fixed speed down-operation to decelerative down-operation, of the elevator, the power supply of the electric motor 2 is switched from the commercial power supply 4 to the inverter power supply 5. In this way, energy can be saved by enabling a loss of energy to decrease.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for operating a hydraulic elevator by inverter drive, and an elevator apparatus thereof.

[Prior Art and Problems to be Solved by the Invention] Conventionally, as one method for controlling the ascending and descending speed of a hydraulic elevator operated by a hydraulic pump connected to an electric motor, an inverter power source is used as the electric motor's power source. There is something I used.

Using an inverter power supply in this way limits the starting current of the motor when the elevator is going up, reduces voltage fluctuations applied to the power supply, and makes the elevator ride comfortable, and when the elevator is going down, the motor rotates at a speed higher than the synchronous speed. It can function as a generator and regenerate the electric power to save energy.

However, even greater energy saving effects were required.

[Means to solve the problem]

As a result of studies in view of this, the present invention provides an operating method and apparatus that achieve reduction in loss in an inverter drive system, simplification of the system, and reduction in noise.

That is, the operating method of the present invention raises and lowers an elevator integrated with a ram by sending hydraulic oil from an oil tank to a cylinder using a hydraulic pump, or by returning the hydraulic oil from the cylinder to an oil tank, and In the operation of a hydraulic elevator in which an electric motor that drives the hydraulic pump is controlled by an inverter power source and its control device, when the elevator shifts from an accelerated ascent to a constant speed ascent after the elevator starts to ascend, and from an accelerated descent after the elevator begins to descend. When transitioning to constant speed descent, switch the electric motor power supply from the inverter power supply to the commercial power supply (frequency 500! or 60H).
The present invention is also characterized in that the power source of the electric motor is switched from the commercial power source to the inverter power source when the elevator moves from the constant speed rise to a deceleration rise, and when the elevator moves from the constant speed fall to a deceleration fall. When the power source of the electric motor is switched to a commercial power source, the electric motor is driven as an induction motor when the transition is from accelerated ascent to constant speed ascent, and furthermore, when the transition is from accelerated descent to constant speed descent, the electric motor is driven as an induction motor. Even more effective is to operate the motor as an induction generator and return the regenerated power to the power source.

The device of the present invention also includes a hydraulic pump that sends hydraulic oil from an oil tank to a cylinder, or conversely returns the hydraulic oil from the cylinder to an oil tank to raise and lower an elevator integrated with a ram, and the hydraulic pump. In a hydraulic elevator system that includes a driving electric motor, an inverter power source that controls the rotation speed of the electric motor, and a control device for the same, the hydraulic elevator system further includes a rotation sensor that detects the rotation speed of the electric motor, and a frequency changer between the inverter power source and the commercial power source. It has a synchronized phase detector for matching, a semiconductor gate controller and an electromagnetic contactor for switching power between the inverter power source and the commercial power source, and when the elevator shifts from an accelerated ascent to a constant speed ascent after the elevator starts ascending. , and when the electric motor is switched from an inverter power source to a commercial power source when transitioning from an accelerated descent to a constant speed descent after the start of descent, and when the elevator is transitioned from a constant speed ascent to a deceleration ascent, and when the electric motor is The electric motor's power source is switched from commercial power source to inverter power source when transitioning from constant speed descent to deceleration descent where the electric motor operates as an induction generator using the power source.

[For production]

In this way, the commercial power supply (50Hz
or 60 tlx), constant speed increase is performed without an inverter, making it possible to greatly reduce energy loss due to the inverter.

Also, when the elevator descends, the hydraulic pump is rotated in the opposite direction, so the electric motor acts as a generator, but if the inverter power supply is connected at this time, a considerable amount of power is consumed by the relays of the inverter control device, etc. Put it away. Therefore, if the commercial power source is switched during constant speed descending operation, the above-mentioned inconvenience will be eliminated.

When switching from a commercial power supply to an inverter power supply, a synchronous phase detector is used to align the frequencies of both types of sources, and at that moment, a semiconductor gate controller that operates at high speed turns on and off the power. to operate a normal electromagnetic contactor. Without such a synchronous phase detector, the power supplies may switch at times when the phases are not in sync, causing sparks at the power switch, which can shorten the life of the equipment and reduce ride comfort. It will have a negative impact. Furthermore, if only a normal electromagnetic contactor is used as a switching device, it takes time to turn on and off the power, which also causes sparks. Therefore, the present invention uses a semiconductor gate controller that performs switching operations at high speed.

〔Example〕

Next, one embodiment of the present invention will be described.

As shown in FIG. 1, an electric motor (2) is connected to a hydraulic pump (1) that drives a cylinder (indicated by CL in the figure) of an elevator (not shown).

A commercial three-phase power supply (4) is introduced into the power supply of this electric motor (2) via a semiconductor gate controller (3) and a magnetic contactor for forward rotation (C2), and a magnetic contactor for forward rotation (C2). ) in parallel with the motor reversing magnetic contactor (C3
) was established. Also, commercial power supply (4) and electric motor (2)
In between, an inverter (5) and an inverter electromagnetic contactor (C3) were provided in parallel with the gate controller (3) and the like.

Note that (6) is a command device that controls the inverter and the following switching operations.

Next, the operation of the elevator will be explained based on FIGS. 1 and 2.

When the elevator is in ascending operation> First, the gate controller (3) and the magnetic contactor (
By turning off C2) and (C3) and inserting the inverter electromagnetic contactor (C1), the inverter power is applied to the electric motor (2), causing the electric motor (2) to rotate forward and being sent out from the hydraulic pump +11. Gradually increase the hydraulic oil discharge pressure.

At this time, the operating valve (7) provided in the hydraulic path communicating with the cylinder (CL) is a check valve (ch) as shown in FIG.
is in effect, so when the discharge pressure reaches a level that overcomes the spring force of the check, the hydraulic fluid flows into the cylinder (CL).
flows into. Then, as the rotation speed of the electric motor (2) is gradually increased, the elevator accelerates upward (■-■ in Figure 2).

The rotation speed of the motor (2) is constantly detected by the rotation sensor (8), and this is the specified rotation speed (i.e., the rotation speed of the motor (2) when using the commercial power source (4)).
When this happens, the synchronous phase detector (installed in the inverter control circuit) matches the frequency phases of the commercial power supply and the inverter power supply, and at that moment the semiconductor gate controller (
3) to ONL, and then inverter magnetic contactor (C
1) and turn on the forward rotation electromagnetic contactor (C2) at the same time, the electric motor (2) is powered by the commercial power supply (4).
(■ in Figure 2) to raise the elevator at a constant speed.

After that, when the speed increases at a constant speed (■→■ in Fig. 2), all operations are performed using commercial power, so that greater energy savings can be achieved compared to when an inverter power source is used.

Next, when entering the stop operation, the synchronized phase detector is activated again to match the frequency phases of the commercial power source and the inverter power source, and the gate controller (3) is turned OFF L, and then the magnetic contactor is turned OFF. Turn (C1) ON and simultaneously turn (C2) OFF' to apply inverter power to the electric motor (2). In this way, by using an inverter when landing on the floor, smoother deceleration and landing motion can be obtained (■→■ in Figure 2)
−■).

<During descending operation of the elevator> At the start of descending operation, the electric motor (2) is not powered, so the motor (2) and hydraulic pump +11
can be rotated freely.

In this state, when a descending signal is first applied, the operation valve (7) is operated and the valve (vl) opens slightly, so the cylinder (
Since the hydraulic oil in the hydraulic pump (CL) flows through the hydraulic pump (1) and returns to the oil tank (9), the pump (1) is rotated in the opposite direction to the direction of rotation when the elevator is in ascending operation (Fig. 2). Medium ■).

At this time, the hydraulic pump (1) and electric motor (2) are synchronized with the inverter using the speed detection sensor (S) installed in the elevator, the elevator position detection sensor (E), etc. By operating the high-speed valve (V2) to open the high-speed valve (V2), the elevator accelerates its high-speed descent without causing vibration (■-■ in Figure 2).
).

The rotation speed of the motor (2) connected to the hydraulic pump (11), which is rotated by the oil returned to the tank (9), gradually increases until the rotation speed measured by the rotation sensor (8) reaches the predetermined level. When the rotation speed of The reversing magnetic contactor (C1) is turned ON and the inverter magnetic contactor (C3) is turned OFF at the same time.In this way, the power source of the motor (2) is switched from the inverter (5) to the commercial power source (4) (see Figure 2). ■), the elevator descends at a constant speed without an inverter (■→■ in Figure 2).

At this time, the electric motor connected to the hydraulic pump +1)
2) (i) Since the motor (2) continues to be rotated in the opposite direction by the downward energy, it will work as an induction generator. Therefore, from the moment the switch is made to the commercial power supply (4), this regenerated energy is returned to the power supply side. In order to act on the motor (2) as an appropriate braking force,
The elevator will descend at a constant speed.

Next, the elevator enters the landing operation at point ■ in FIG.

At this time, the synchronous phase detector is activated again, and first the gate controller (3) is turned OFF L, and the electromagnetic contactor (C3) is turned OFF.
F and (C1) are turned on at the same time, and the power source of the motor (2) is switched from the commercial power source (4) to the inverter power source (5) again, so the speed of the elevator is smoothly reduced by the inverter drive (second (■ in the figure). At this time, it is assumed that the high speed valve (v2) gradually closes according to the deceleration control of the inverter.

When the elevator descends, the operation valve (7) is operated only immediately after the start and immediately before the end of the descending operation, in order to improve the ride comfort of the elevator and the positioning accuracy when landing on the floor.

Furthermore, in this embodiment, the inverter is controlled while monitoring the movement of the elevator using the speed detection sensor (S) and position detection sensor (E) of the elevator, and the rotation of the pump (1) using the rotation sensor (8). Therefore, the operation is equivalent to compensating the pressure and temperature of the pump (11).In other words, even if the leak compensation of the hydraulic pump (1) is not performed, the speed of the elevator itself can be detected, etc. This allows sufficient control.

〔Effect of the invention〕

As described above, according to the present invention, in an inverter drive system for an elevator hydraulic pump, energy loss is reduced, resulting in even more energy-saving effects, and since a semiconductor gate controller is used, power can be turned on and off at high speed. This has significant effects such as improving the ride comfort of elevators and extending the life of electromagnetic contactors.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the device configuration of the present invention, and FIG. 2 is an explanatory diagram showing an operating pattern of a hydraulic elevator. 1... Hydraulic pump, 2... Electric motor, 3...
Semiconductor gate controller, 4...Commercial power supply, 5...Inverter power supply, 6...Command unit, 7...Operation valve, 8...
- Rotation sensor, 9...Oil tank, C1...Magnetic contactor for inverter, C2...Magnetic contactor for forward rotation, C3...Magnetic contactor for reverse rotation. Figure 1 Figure 2

Claims (3)

[Claims] (1) By sending hydraulic oil from the oil tank to the cylinder using a hydraulic pump, or by returning the hydraulic oil from the cylinder to the oil tank, the elevator integrated with the ram is raised and lowered, and the inverter power source and its control are used. In the operation of a hydraulic elevator in which an electric motor that drives the hydraulic pump is controlled by a device, when the elevator shifts from an accelerated ascent to a constant speed ascent after the elevator starts to ascend, and from an accelerated descent to a constant speed descend after the elevator begins to descend. When switching the electric motor power supply from an inverter power source to a commercial power source (frequency 50 Hz or 60 Hz), and when transitioning from the above-mentioned constant speed upward movement of the elevator to a decelerated upward movement, and when the above-mentioned constant speed downward movement to a decelerated downward movement of the elevator. A method of operating a hydraulic elevator using an inverter drive system, characterized in that the electric motor's power source is switched from commercial power source to inverter power source. (2) When switching the power source of the electric motor to a commercial power source, if the transition is from acceleration up to constant speed up, the electric motor is driven as an induction motor, and if the transition is from acceleration down to constant speed down, The method for operating a hydraulic elevator according to claim 1, wherein the electric motor is operated as an induction generator to return regenerated electric power to the power source. (3) A hydraulic pump that sends hydraulic oil from an oil tank to a cylinder, or vice versa, and returns the hydraulic oil from a cylinder to an oil tank to raise and lower an elevator that is integrated with a ram, and an electric motor that drives the hydraulic pump. In a hydraulic elevator system comprising an inverter power supply for controlling the rotation speed of the electric motor and a control device thereof, a rotation sensor for detecting the rotation speed of the electric motor, and a synchronization phase for matching the frequencies of the inverter power supply and the commercial power supply. It has a detector, a semiconductor gate controller, and an electromagnetic contactor that switches the power supply between an inverter power source and a commercial power source, and when the elevator shifts from an accelerated ascent to a constant speed ascent after the elevator starts rising, and when the elevator starts descending. Later, when transitioning from accelerated descent to constant speed descent, the power source of the electric motor is switched from the inverter power source to commercial power supply, and during the above descent, the electric motor is operated as an induction generator, and the elevator transitions from the above constant speed increase to deceleration descent. An inverter drive system is used, which is characterized in that the electric motor's power source is switched from the commercial power source to the inverter power source when the electric motor operates as an induction generator using the commercial power source, and when transitioning from constant speed descent to deceleration descent where the electric motor operates as an induction generator using the commercial power source. Hydraulic elevator equipment.