JPH0550435B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an elevator starting control device,
In particular, the present invention relates to a starting control device suitable for inverter-controlled elevators.

[Background of the invention]

Generally, elevators have a structure in which a car and a counterweight are suspended in a hanging sheave connected to a drive motor, and when the elevator is stopped, the elevator is braked and held.

Also, since there is a difference between the weight of the car including the live load and the weight of the balance weight, if the braking torque of the brake is released while the electric motor torque remains zero when starting the elevator, the unbalanced torque will cause This will cause a shock. Therefore, in order to reduce this shock, a method is widely adopted in which the load of the car is detected, the drive motor generates a torque corresponding to the unbalanced torque, and then the braking torque is released.

Methods for controlling such electric motor torque according to the detected load amount include a method in which a torque command is given to the motor torque control circuit based on the detected load amount, and the brake is released after generating torque in accordance with the torque command, or As in Special Publication No. 50-22775,
A method is known in which the drive motor torque is changed at a constant rate and the brake is released at a time corresponding to the detected load amount.

However, all of these methods require a device for detecting the load inside the car, and it takes time to adjust the device. Furthermore, if the load detector has deteriorated over time, or if the weight compensation of the main rope and compensating rope is not perfect, there is a problem that the unbalanced torque acting on the motor cannot be appropriately compensated for.

Therefore, as a method that does not use such a load detector, as disclosed in Japanese Patent Publication No. 60-6278, when the car tries to move due to unbalanced torque when the braking torque is released, the movement is detected from the acceleration signal. It has also been proposed to alleviate the shock by feeding back this acceleration signal to the acceleration control circuit.

In order to suppress the movement of the car only by feedback of the acceleration signal, it is necessary to increase the gain of the acceleration control circuit, which causes oscillation in the control system.
Therefore, as a measure to prevent oscillation, a circuit is provided to gradually reduce the gain as the braking torque is released, thereby ensuring stability of startup.

However, in such an acceleration feedback method, the number of parts increases because a gain gradually decreasing circuit is used, and since the gain of the acceleration control circuit must be high at least at the beginning of brake release, it becomes susceptible to noise.

[Purpose of the invention]

The present invention has been made in view of the above points, and its object is to compensate for the unbalanced torque of the car and the balance weight and the weight of the main rope by the conven rope by using a single detection means without using a load detector. An object of the present invention is to provide an elevator starting control device that eliminates the shock at the time of elevator starting caused by unbalanced torque when the torque is incomplete, reduces the cost required for starting compensation, and has excellent noise resistance. be.

[Summary of the invention]

In order to achieve the above object, the present invention provides an elevator driving electric motor, a hoisting sheave driven by the electric motor, a car and a balance weight suspended from the sheave via a rope, and a balancing weight for the electric motor. In an elevator equipped with a brake that brakes the rotation of the motor and releases this braking torque at startup, and an inverter control device that supplies power to the motor and controls the motor, the above-mentioned braking at the floor stop position is performed before the elevator starts traveling. a movement amount detection means for detecting the movement amount and movement direction of the car movement caused by unbalanced torque at the time of torque release at the time of minute displacement; A feedback means is provided for generating electric motor torque for controlling the fixed position of the car by applying feedback to counteract the above.

With such a configuration, in the process of releasing the braking torque of the elevator upon startup,
When the car tries to move due to unbalanced torque due to the weight difference between the car and the balance weight, the movement amount detection means detects the sign when the car undergoes a minute displacement.

When the amount of movement and its direction are detected, feedback is applied to the inverter control device to cancel the amount of movement. This generates a motor torque that keeps the car in a fixed position (floor stop position), alleviates the shock caused by unbalanced torque at startup, and ensures a smooth start of travel.

Starting compensation for unbalanced torque using the car displacement signal described above is reliable and has a sufficient effect on shock mitigation because it generates the motor torque that attempts to maintain the floor stop position from the amount of car movement. do.

Note that, in addition to the above-mentioned movement amount, if the first derivative value (velocity) or second derivative value (acceleration) thereof is used in feedback control, not only reliability but also responsiveness can be improved.

In addition, when performing feedback control on the travel amount signal, it is possible to form the motor torque for unbalanced torque compensation without making the torque control system high gain or unbalanced torque high gain, which improves noise resistance. .

In addition, when acceleration is used in addition to the movement amount for feedback as described above, the feedback control using acceleration is used to supplement the starting compensation using the movement amount signal, and the main compensation torque is generated by the feedback of the movement amount signal. Therefore, high gain acceleration control like the conventional one is not required.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention.

This embodiment is an example in which the moving amount of the car is detected by the position detector 23, where 1 is a power source, 2 is a converter main circuit, 3 is an inverter main circuit, 4 is a reactor, and 5 is a converter main circuit.
is a drive motor, 6 is a current detector, 7 and 11 are base drive circuits, 8 and 12 are pulse distributors, 9 is a current control circuit, 10 is an addition point of the current command I and the current feedback signal, and 13 is a vector conversion circuit, 14 is a vector calculation circuit, f is a frequency command, θ is a phase command, I is a current command, It is a torque current command, 15 is a speed control circuit, 16 is an addition point of the speed command and the actual speed, 17 is an encoder , 19 is a sheave, 19 is a brake, 25 is a brake coil, 20 is a main rope,
21 is a balance weight, 22 is a car, 23 is a position detector that detects the relative position of the car and the floor;
24 is a movement amount converter, 26 is a compensation rope that compensates for the weight of the main rope, and 27 is a speed command device.

FIG. 2 is an explanatory diagram of the starting operation, in which FIG. 2A shows the state when there are no passengers, and FIG. 2B shows the state when the vehicle is full. In the figure,
T _UB is the unbalanced torque due to the difference between the car weight including passengers and the weight of the balance weight, T _B is the braking torque generated as a reaction to the unbalanced torque, T _M is the motor torque generated by the drive motor, and V ₁ is the elevator speed when the present invention is not used, V ₂ is the elevator speed when the present invention is used, and V _P is the speed command.

FIG. 3a is a characteristic diagram of the position detector 23 and the movement amount converter 24. Figure 4 shows the torque response characteristics, where T _B is the torque response characteristic of the brake and T _M is the torque response characteristic of the electric motor.

Now, the activation of the elevator when there are no passengers in the car will be explained using FIG. 2a.

Since the weight of the car including passengers is lighter than the weight of the balance weight, an unbalanced torque T _UB is generated. On the other hand, the braking torque of the brake is -T _B , and the car is stopped and held. At startup, time
When current is applied to the brake coil 25 at time t ₁ , the brake starts to release, and the brake torque T _B gradually decreases until time t _2.
becomes zero, and the composite torque T of the braking torque T _B and the unbalanced torque T _UB increases, so the car starts accelerating in the upward direction at the elevator speed V ₁ . In other words, the elevator speed is in line with the speed command V _P while causing a pop-out phenomenon.

Conversely, when the car is full, as shown in Figure 2b, the resultant torque T causes the car to accelerate in the opposite direction to the command at a speed V ₁ curve, that is, a reversal phenomenon occurs. However, the elevator speed is in line with the speed command V _P. That is, in either case, after being accelerated by the resultant torque T, at time t ₂
It will be controlled according to the speed command given by . Therefore, the popping-out or reversing phenomenon causes a starting shock, which causes discomfort to passengers.

In this embodiment, in order to eliminate the above-mentioned problem, the output of the position detector 23 is applied to the speed addition point 16 through the movement amount converter 24 before the elevator starts (starts running).

That is, the position detector 23 has a function of detecting the relative position between the car 22 and the floor position,
When starting an elevator, it serves as a movement amount detection means that detects the position of the car, which changes due to the weight difference between the car and the equilibrium torque when the braking torque is released, at the stage of minute displacement (minute amount of movement), along with its directionality. to do.

Then, based on the movement amount signal (minimal displacement signal) of the position detector 23, the movement amount converter 24 generates (a) a signal approximately proportional to this movement amount signal (this signal is an increase signal for canceling the movement amount). A command value or a descending command value is generated (herein referred to as a position control signal), and this position control signal is matched with the addition point 16 of the speed control circuit feedback system via the signal line a, and is ) The position signal (travel amount signal) from the position detector 23 is differentiated to generate either a differential signal (that is, a speed signal) or a second-order differential signal (that is, an acceleration signal), and the signal line is Match to addition point 16 via b. In this case, the signal from the speed command device 27 applied to the addition point 16 is zero.

Figure 3a is a signal characteristic diagram showing the operation of (a) above, where the horizontal axis represents the upward displacement with respect to the floor surface O using the position signal (travel amount signal) x from the position detector 23. The positive direction and downward displacement are defined as negative directions. The vertical axis is the position control signal (ascend command value, descend command value) of the car; when the car moves above the floor, a negative signal value (descend command value) is generated; When moving downward, a positive signal value (ascent command value) is generated, and this position control signal value is a value proportional to the distance (displacement) of the car position x.

Figures 3b and 3c are signal characteristic diagrams of (b) above, and figure b is the one obtained by differentiating the position signal x, with the horizontal axis representing the car position x and the vertical axis representing the car speed dx/dt. show,
Figure c shows the second-order differential of the position signal x, with the horizontal axis representing the car position x and the vertical axis representing the car acceleration (2
(order differential value).

In FIG. 3b, indicates the case where the speed is constant, and indicates the case where the speed increases. Also, the third
In Figure c, indicates the acceleration when the acceleration is constant and increases, and indicates the acceleration when the acceleration increases while changing.

According to this embodiment, which operates as described above, when current is applied to the brake coil 25 at time _t1 , the brake torque increases.
T _B decreases and the car 22 tries to move due to the unbalanced torque T _UB , but the position detector 2
3. The feedback position control loop consisting of the travel amount converter 24 and the speed addition point 16 allows the car 22 to
Generates electric motor torque T _M for fixed position control (convergence control) that keeps the motor at a fixed position, acts so that the sum with brake torque T _B becomes equal to unbalanced torque T _UB , and from time t ₁ to t ₂ , the elevator stands still without the car popping out or reversing, and as a result, even if the braking torque is completely released at time t ₂ and a speed command for running is given, the passenger will not receive a starting shock. .

In other words, the above effect can be achieved because feedback is applied to the inverter control device of the elevator to cancel the amount of movement of the car. This is done using a second-order differential signal. That is, a motor torque T _M for performing fixed position control is generated using the position control signal on the signal line a, and this motor torque T _M
is generated at a speed faster than the torque fluctuation of the brake 19 by the signal on the signal line b.

Figure 4 shows the responsiveness of braking torque T _B and electric motor torque T _M in this example, and shows the response of the differential value or 2
As shown in Figure 4, using the step differential value, the response of the motor torque T _M can be made approximately 1/10 earlier than the braking torque T _B , and by applying this to inverter control, T _UB = T _B Since + _TM conditions can be quickly set, extremely smooth startup characteristics can be obtained.

Furthermore, the position detector 23 used in this embodiment can also be used as a position detector for re-aligning the floors when the elevator decelerates and stops and the floors do not match. It can be constructed at low cost and at low cost.

In the embodiment, the output of the movement amount converter 24 may be gradually decreased after the speed command rises at time _t2 , similar to the conventional load compensation based on load detection.

FIG. 5 shows another embodiment of the present invention, and the same parts as those in the previous embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted. This embodiment is characterized in that the output of the speed detector 17 is added via the movement amount converter 28 to the addition point 16 of the speed command and the actual speed. The movement amount converter 28 integrates the signal of the speed detector 17, and
The system is configured to detect the amount of movement of the car from the amount of rotation of the rotating body.

Therefore, if this movement amount converter 28 is
If the car is configured to have the same car position characteristics as shown in FIG.
T _UB suppresses the movement of the car and provides smooth starting characteristics with no shock.

Further, the movement amount converter 28 may be configured to simply integrate the signal of the speed detector 17 and obtain only the movement amount at the time of startup, regardless of the floor and floor surface. In this case, the amount of movement can be obtained based on the car position before startup, so even if the car is started from a position that does not match the floor surface, an appropriate compensation torque can be applied.
It is more practical because it can generate _TM .

FIG. 6 shows still another embodiment, in which the signal from the position detector 23 is applied to the velocity addition point 16 via a movement amount converter 29, and the signal from the position detector 23 is applied via an acceleration converter 30. Torque addition point 3
The feature is that the voltage is applied to 2.

Here, the output signal of the movement amount converter 29 generates a position signal shown in FIG. 3 and a differential signal of the position signal, that is, a speed signal, and serves to align the car position x with the floor surface.

The acceleration converter 30 generates an acceleration signal obtained by second-order differentiation of the position signal, and applies it to the torque addition point 32 of the torque command current, which is the output of the speed control circuit 15. Therefore, this acceleration loop allows the movement of the car to be suppressed more quickly, resulting in smooth starting characteristics.

FIG. 7 shows another embodiment, in which the position signal obtained in FIG. 6 is obtained from the speed detector 17.

The signal from the speed detector 17 is applied to the speed addition point 16 via a movement amount converter 28 that obtains the amount of rotation of the rotating body, and the signal from the speed detector 17 is applied to the acceleration addition point 32 via an acceleration converter 31. An acceleration feedback loop is provided. The loop through the displacement transducer 28 serves to restrain and hold the car position x in alignment with the floor. The acceleration loop via the acceleration converter 31 quickly catches the movement and acts to stop the movement, so that a smooth starting characteristic without a shock is obtained.

As described above, various embodiments have been described, but in each embodiment, since an effective load detector is not used, it is possible to not only smooth the starting characteristics of the elevator with an inexpensive device, but also Since there is no change in the starting characteristics due to changes, effects such as no need for maintenance, inspection, and adjustment can be obtained.

Furthermore, since the load detector is generally installed using anti-vibration rubber, leaf springs, etc., it receives the load of the car as a concentrated load. Therefore, strong members that can withstand this load have to be used, which tends to increase the weight of the car frame, etc. However, since a load detector is no longer required, the weight of the members can be reduced. Not only can the weight of the car be reduced and the electric motor and control equipment be made smaller, but also the peak electric power consumed by the elevator can be reduced, and power consumption can also be reduced.

Furthermore, since starting compensation is performed using unbalanced torque based on the amount of movement of the car, in addition to the unbalanced torque between the car 22 and the balance weight 21, there is also a possibility that the compensation of the weight of the main rope 20 by the compensation rope 26 is incomplete. Starting compensation that also takes unbalanced torque into account can be performed by one common detection means and feedback loop.

For the above reasons, the accuracy of the compen rope 26 is not required to be very strict, and the compen rope 26
Since the number of can be reduced, it is possible to expect a highly economical device.

〔Effect of the invention〕

As described above, according to the present invention, unbalanced torque (unbalanced torque between the car and the balance weight In addition, compensation can be performed to eliminate the shock at elevator start-up caused by unbalanced torque (when the weight compensation of the main rope by the compensation rope is incomplete).

Moreover, the reliability of starting compensation for unbalanced torque is increased, and since there is no need to make the feedback control system high gain unlike starting compensation using a conventional acceleration control circuit, starting compensation is performed with sufficient noise resistance. Furthermore, since a gain gradual reduction circuit is not required, the number of parts can be reduced and costs can be reduced.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an embodiment of an elevator starting control device according to the present invention, Fig. 2 is a diagram explaining the starting operation, Fig. 3 is a characteristic diagram of a position detector and a movement amount converter, and Fig. 4 is an inverter. Control torque response and brake torque response characteristic diagrams, Figures 5 and 6,
FIG. 7 shows another embodiment of the invention. 1...Power supply, 2...Converter main circuit, 3...
Inverter main circuit, 4...Reactor, 5...Drive motor, 6...Current detector, 17...Speed detector, 19...Brake, 23...Position detector, 24
...Movement amount converter, 28, 29...Movement amount converter, 32...Torque addition point, I _t ...Torque current command.

Claims (1)

[Scope of Claims] 1. An electric motor for driving an elevator, a hoisting sheave driven by the electric motor, a car and a balance weight suspended from the sheave via a rope, and a balance weight that controls the rotation of the electric motor. In an elevator equipped with a brake that applies braking and releases this braking torque at the time of startup, and an inverter control device that supplies power to the motor and controls the motor, the above-mentioned braking torque is released at the floor stop position before the elevator starts running. movement amount detection means for detecting the movement amount and movement direction of the car movement caused by the unbalanced torque of the car at the point of minute displacement; 1. A starting control device for an elevator, comprising: a return means for generating electric motor torque for controlling the fixed position of the car by applying the return of the elevator car. 2. In claim 1, a position detector that detects the relative position of the car and the floor is used as the movement amount detection means, and the output signal of the position detector is used to determine the amount of movement caused by the unbalanced torque. An elevator start control device that is set to calculate the amount of car movement. 3. The elevator starting control device according to claim 1, wherein the movement amount detection means is set to integrate the output of the elevator speed detector to determine the movement amount of the car caused by the unbalanced torque. 4. In any one of claims 1 to 3, when the movement amount detection means applies the feedback to the inverter control device,
An elevator starting control device configured to detect and detect a minute displacement of the car when the braking torque is released, which is taken based on the car position. 5. In any one of claims 1 to 4, the feedback means is configured to return the amount of movement of the car and its first derivative to a matching point of the speed command control system. Elevator start control device. 6. In any one of claims 1 to 4, the return means returns the amount of movement of the car to a point where it matches the speed command, and calculates the second derivative of the amount of movement of the car. An elevator starting control device configured to feed back a value to a torque current command section of the inverter control device.