HK1148995B - Arrangment and method for adapting the parameters of transport system - Google Patents

Description

Device and method for configuring parameters of a transport system

Technical Field

The invention relates to a device and a method for configuring transport system parameters. The configuration of the parameters is implemented using a power model of the transport system.

Background

In transport systems, such as elevator systems, it is necessary to identify some system parameters for control, maintenance, etc. Traditionally, system parameters are determined by calculation or testing. However, such methods are accompanied by problems leading to inaccurate determinations. For example, errors in elevator system measurements will interfere with elevator control.

Specification EP1361999 describes call allocation in an elevator group by using a specific energy consumption file for each elevator car.

Specification US5157228 describes a method for learning elevator control adjustment parameters.

Disclosure of Invention

It is an object of the invention to disclose an arrangement and a method for configuring parameters of a transport system by using a specific power model describing the power flow in the transport system. When configuring transport system parameters according to the invention, even a large number of parameters can be configured using only a small amount of measurement data. The invention also enables better accuracy in parameter configuration than in the prior art.

The transport system according to the invention may be, for example, an elevator system, a crane system, an escalator system or a travelator system.

The arrangement according to the invention for configuring parameters in a transport system comprises a power model comprising a number of parameters describing the power flow in the transport system. The apparatus includes at least first and second input parameters whose values are determined, and updates the power model using at least the first input parameter. The apparatus also includes at least one state parameter, a value of which is configured using at least the updated power model and the second input parameter.

The configuration of the parameters involves modifying at least one state parameter such that the power model is adjusted with certain optimization criteria. The input parameters relate to parameters for which data are determined from the transport system, for example by reading. These parameters may for example comprise the rotational speed of the traction sheave of the elevator or the acceleration of the elevator car, which parameters may for example be measured from an encoder attached to the motor shaft or the traction sheave of the elevator or from an acceleration sensor mounted on top of the elevator car. The input parameters may also include, for example, measured motor feed power data, measured, for example, from motor current and voltage. Similarly, a "status parameter" relates to a parameter describing the transport system, but the value of the parameter has not been determined from the transport system. The status parameters may be lockable, in which case the parameters are configured only for those parameters that are not locked. The parameters of the lock remain unchanged during the configuration process. In an embodiment of the invention, the same power model according to the invention may also be used for a plurality of different parameter configuration processes, wherein an input parameter may function as a status parameter in another configuration process and vice versa. In an embodiment of the invention instantaneous values are read simultaneously for input parameters, and the parameters that have been read simultaneously form a continuous set of parameter elements in which the parameters correspond to each other.

In the method for configuring parameters of a transport system according to the invention, a power model arrangement; parameters describing the power flow in the transport system are adapted to the power model; determining at least first and second input parameters of the transport system; updating the power model based on the at least first input parameter thus determined; and updating at least one state parameter of the transport system using the updated power model and the second input parameter.

Advantages achieved by the present invention include at least one of the following:

since the state parameters of the transport system are configured by using the power model updated on the basis of the first input parameters and by using the separately determined second input parameters, the power model can be adjusted towards the power values derived from the second input parameters by modifying the state parameters, whereby the state parameter values are likewise adjusted.

Since in the power model the power flow in different parts of the transport system is modeled in a chain manner such that the power flow at a point within the transport system depends on the power flow in other parts of the transport system, the power model can be used to configure a number of transport system parameters in different parts of the transport system, instead of having to require measurements of feedback from all these parts of the transport system, thus simplifying the apparatus.

After parameter configuration has been performed based on the power flow at the mechanical connection point between the motor drive and the transport appliance, the parameters may be configured, for example, based on measurements of the motor power input and of the movement of the motor drive wheels.

If the transport system state parameters have been preselected by means of measurements, for example by means of measurements of the load of the elevator car, measurements of the slip of the elevator ropes or measurements of the friction between the elevator car and the guide rails in the elevator system, the measurement errors can be reduced via the parameter configuration according to the invention.

Transport system state parameters preselected by calculation, such as rope constants of the elevator ropes or imbalance of the rope loads, can likewise be adjusted in the manner described in the invention.

Elevator system state parameters configured according to the invention can be used, for example, in the control of the power supplied to the elevator motor, so that on the basis of these elevator system state parameters control parameters of a power controller, such as a frequency converter, can be determined, for example, torque feed forward.

The power model of the invention can also be applied in traffic control of e.g. elevator systems. The power consumption of the elevator system determined by the power model can thus be used, for example, as a criterion in the allocation of elevator calls. The aforementioned traffic control is also more accurate, since the parameters in the power model are now configured according to the invention.

Since the status parameters can be reconfigured during the service life of the transport system according to the invention, changes, for example due to wear of the transport system, can be taken into account by updating the status parameter values. On the other hand, this also enables the state of the transport system to be observed from changes in the state parameters, and this information can be used, for example, for maintenance.

The power model of the invention can be used for monitoring an elevator system by comparing parameters determined by means of the power model with parameters based on actual measurements.

Drawings

The invention will be described in detail hereinafter with reference to the accompanying drawings, in which:

fig. 1 shows an elevator system power model according to the invention.

Fig. 2 shows an arrangement according to the invention for parameter configuration in an elevator system.

Fig. 3 shows a power model describing the efficiency of a motor according to the invention.

Fig. 4 shows a power model describing the efficiency of a motor power supply according to the invention.

Fig. 5 shows an embodiment according to the invention.

Detailed Description

Fig. 1 shows a block diagram representing an elevator system power model according to the invention. In the power model, the power flow in the elevator system is described by means of elevator system parameters 2, 3, 4, 13. Power is supplied to the elevator system from a power supply 27, which in this example is a network supply, but which may also be a generator, for example. The motor power supply 14, the elevator control panel 29, and the lighting device 30 receive power supplied thereto from the power supply 27. The motor drive comprises blocks describing the power flow in the motor power supply 14 and the elevator motor 15. The elevator car, counterweight and elevator ropes form a block 17 describing the power flow in the elevator shaft mechanism. Power flows from the elevator traction sheave 16 to the elevator shaft mechanism via the elevator ropes.

Input power 9 for the motor drive is supplied to the elevator motor 15 via a motor power supply 14. The motor power supply means delivers the input power 9 in accordance with its efficiency (eta)_D) Acting as a motor to provide power 3, but some of the input power is converted into heat 18. A proportion of the motor supply power 3 is required as magnetizing power (P)_Mmg). In addition, some power is dissipated in the motor coils due to resistive losses and, for example, due to eddy currents. This power dissipation is converted into heat 18. The motor being at its efficiency (η)_Mi) The power is transmitted to the elevator shaft mechanism 17 via an elevator rope, which is mechanically connected to the drive wheel 16. From this connection point 5 between the motor drive and the mechanism, power is further transmitted through the elevator rope, some of which is converted into heat 18(P (σ)) as the elevator rope slides over the traction sheave. For the power 28 transferred to the pit mechanism 17, part is due to friction (F) in the pit_μ) Converted into heat and a part is stored as the elastic constant (K) of the rope from the elevator_RSμ) A determined potential energy in the spring and a part as an inertia K based on the elevator rope_RSiKinetic energy of momentum of j. Energy is also stored as kinetic energy and potential energy of the elevator car, the elevator car load and the counterweight.

Fig. 2 shows an arrangement according to the invention for the configuration of elevator system parameters. The arrangement comprises a power model 1 comprising a number of parameters 2, 3, 4 and 13 describing the power flow in the transport system. In the arrangement, the first input parameter 2 comprises data representing the rotational speed of the elevator motor, from which elevator motor acceleration data are obtained via derivation and drive wheel position change data are obtained via integration. The second input parameters 3 comprise elevator motor supplied power corresponding to speed data 2 and the third input parameters 13 comprise elevator motor magnetizing power corresponding to zero speed. The data of the input parameters are simultaneously read and stored as a parameter set. The read operation is repeated at regular intervals, thus forming a continuous set of parameters whose values are stored.

The elevator is operated by running it at least twice successively in the direction of heavy and light load, i.e. in the opposite direction to the elevator shaft, and the input parameters are read. The power model is updated with elevator motor speed data and elevator motor magnetizing power corresponding to zero motor speed, and the power flow at the connection point 5 between the motor drive and the transport equipment mechanically connected to the motor drive is estimated, wherein these data items have been read. The resulting power estimate 6 is compared with a corresponding power flux value 7 derived from the elevator motor supplied power 3 at the aforementioned connection point 5. By configuring the selected state parameters 4 of the power model using the well-known cost functions 25, 26, the selected state parameters 4 are modified such that the estimate 6 of the power flow at the connection point 5 approaches the power flow value 7 derived from the supplied power 3 of the elevator motor. Now the difference 8 between the estimated power 6 and the power 7 derived from the motor supplied power is determined, the cost functions 25, 26 tend to minimize this difference 8 by configuring the selected non-locked state parameter 4. At the same time, the values of the configurable parameters are adjusted. The motor power flow 7 at the connection point 5 has been derived from the motor supply power 3 by using a model 25 describing the motor efficiency and the traction sheave. Fig. 2 shows the following state parameters 4: motor efficiency 12, motor magnetization constant K_mgElevator car mass 10, elevator inertia mass 19, elevator shaft friction 20, rope constant 21 of the elevator ropes, and change of the elevator system equilibrium position as a function of position 22 in the elevator shaft.

Fig. 3 shows a power model describing the efficiency of the motor. The efficiency relates to the relation between the supplied power 3 and the output power 28 of the motor.

The motor supply power 3 is dissipated as magnetizing power 13, motor friction losses, copper losses in the magnet coils, as eddy currents, i.e. as internal losses 31 in the motor, and as losses due to the sliding of the rope on the traction sheave. These rope slip losses can be expressed as component 33 proportional to the drive wheel power PMtw 34:

(1-η_σ)P_Mtw。

fig. 4 shows a power model describing the efficiency of the motor power supply. In the power model, the efficiency is determined individually according to the direction of power transfer in such a way that the efficiency η_DFWDTo transfer power from a power source P_D27 to the motor P_M15, wherein:

and with an efficiency η_DREVProviding power from the motor to a power source, wherein:

from block input efficiency η_iInput power P_inAnd an initial power value P₀The output power P in the power model block can be updated by linearly configuring the condition_out：

P_out(Pi_n)=ηiP_in+P₀。

Using input efficiency η_iInput power P_inAnd an initial power value P₀The internal efficiency η of the power model block can be reconfigured:

figure 5 shows an embodiment of the invention in which the gain of the car load weighing device and the amount of its zero error are determined. The load weighing device of the elevator car is used for the measurement of the load Q in the elevator car, for example the total mass of passengers. The load weighing device is a measuring device, for example based on a strain gauge, in which the strain gauge signal u is proportional to the car load Q_LWDAmplified and converted into a digital measurement signal, for example in an elevator control system. Q can be calculated from the following equation:

Q=G*u_LWD+O，

where G is the car load signal gain and O is the zero offset. Since the invention can also be used for the estimation of the car load Q, it is possibleBy using the power model, the car load weighing means are weighed in dependence on the respective measurement signal u during operation of the elevator, preferably during normal transport operation_LWDAnd an estimated car load Q, generating a measurement pair. In the example according to fig. 5, the power model uses the car acceleration a (t) as a first input parameter and uses the copper loss P of the motor_CuAs a second input parameter. A set of parameters P1 (-) is assigned to the power model, said set of parameters comprising the state parameters required in the calculation of Q, which have been determined, for example, by a test operation of the elevator. A set of parameters P0 (-) is obtained from the optimizer, which set of parameters P0 (-) includes an estimate of the car load Q or a quantity proportional to the load, and the value of Q can be calculated based on the set of parameters P0 (-). After a sufficient number of measurement pairs Q and u have been collected_LWDThe gain G and zero offset O values may then be calculated using linear attenuation. The application makes it possible to automatically calibrate the measurements obtained from the car load weighing device. The measurement signal from the car load weighing device can also be corrected regularly, e.g. every other day, which will improve ride comfort etc. since the elevator control system receives accurate data from the car load weighing device about the load in the elevator car. Furthermore, sudden differences in measured and estimated car load or changes in gain and/or zero offset of the car load weighing device can be detected quickly and this information can be used, for example, to indicate a fault situation and, in general, to monitor the elevator system. By accounting for e.g. gain and zero offset values of the maintenance center on a long-term basis, inferences can be made about the maintenance required for the elevator system.

The invention is not restricted exclusively to the above-described embodiment examples, but many variations are possible within the scope of the inventive concept defined by the invention.

Claims (11)

1. An apparatus for configuration of parameters in a transport system, the apparatus comprising a power model (1) comprising a number of parameters (2, 3, 4, 13) describing the power flow in the transport system, wherein the apparatus comprises at least a first input parameter (2) and a second input parameter (3), the values of which are determined, the power model (1) is updated using at least the first input parameter (2), and the apparatus comprises at least one state parameter (4), the value of which is configured by using at least the updated power model (1) and the second input parameter (3),

wherein the transport system is an elevator system and the aforementioned input parameters (2, 3, 13) of the elevator system comprise at least one of the following parameters:

-motor driver input power (9);

-the motor provides power (3);

-movement (2) of the driving wheel of the motor;

-movement of the elevator car;

-the magnetizing power of the motor at zero speed (13);

wherein the content of the first and second substances,

the transport system state parameters (4) are preselected based on a system configuration, the first input parameters (2) comprise instantaneous elevator motor motion data, the second input parameters (3) comprise instantaneous elevator motor supply power corresponding to the instantaneous elevator motor motion data (2), the apparatus comprises third input parameters comprising an instantaneous magnetization power (13) corresponding to a zero speed of the elevator motor, a first power flux value (6) corresponding to the elevator motor motion data (2) estimating power delivered by the elevator motor drive wheel by applying the power model using the elevator motor motion data (2), the elevator motor magnetization power (13) and the aforementioned state parameters (4), derived from the supply power (3) corresponding to the instantaneous elevator motor motion data (2) for driving by the elevator motor -a second power flux value (7) of the power delivered in turns, and-by further configuring at least one pre-selected parameter (4) -modifying said first power flux value (6) towards said second power flux value (7).

2. An arrangement according to claim 1, characterized in that for the power flow at least one point (5) in the transport system a first power flow value (6) is estimated using the power model, a second power flow value (7) corresponding to the first power flow value (6) is derived from the aforementioned second input parameter (3), and at least one of the state parameters (4) of the transport system is configured on the basis of a deviation (8) between the aforementioned first power flow value (6) and second power flow value (7).

3. An arrangement according to claim 1, characterized in that the transport system comprises a transport device and a motor drive mechanically connected to the transport device, that for the power flow at the connection point (5) between the motor drive and the transport device a first power flow value (6) is estimated using the power model, and that for the power flow at the connection point a second power flow value (7) is derived from the second input parameter, and that at least one status parameter (4) of the transport device is configured on the basis of the deviation (8) between the aforementioned first and second power flow values.

4. A device according to any of the preceding claims 2-3, characterized in that the aforementioned first power flux value (6) is configured to be modified towards the aforementioned second power flux value (7) by configuring the value of the at least one status parameter (4).

5. Device according to claim 1, characterized in that the aforementioned status parameters (4) of the elevator system comprise at least one of the following parameters:

-an elevator car load (24);

-a mass (10) of the elevator car;

-a counterweight mass (11);

-a motor efficiency (12);

-the efficiency of the motor power providing means (14);

-an elevator inertial mass (19);

-elevator shaft friction (20);

-the spring constant (21) of the elevator rope;

-an elevator system balance error (22);

-slipping (23) of the elevator rope on the drive wheel.

6. A method for configuring parameters of a transportation system, in which method:

-applying a power model (1) to the device,

-parameters (2, 3, 4) describing the power flow in the transport system are applied to the power model,

wherein the content of the first and second substances,

-determining at least a first input parameter (2) and a second input parameter (3) of the transport system;

-updating the power model (1) based on the at least first input parameter (2) thus determined;

-configuring at least one transport system state parameter (4) using at least the updated power model and the second input parameters (3),

wherein the content of the first and second substances,

-the elevator system is applied as a transport system of interest;

-pre-selecting elevator system status parameters (4);

-the elevator is run in the direction of heavy and light load and at least elevator motor (15) movement data is read as the aforementioned first input parameter (2), instantaneous supply power corresponding to the elevator motor movement data is read as the aforementioned second input parameter (3) and motor magnetization power (13) corresponding to the zero speed of the elevator motor;

-showing the power flow at the elevator motor drive wheel by a first power flow value (6) based on pre-selected state parameters, measured elevator motor drive wheel speed data and motor magnetizing power (13);

-deriving a second power flux value (7) for the power flux at the elevator motor drive wheel corresponding to said first power flux value (6) based on the measured elevator motor supplied power;

-said first power flux value is configured to a value substantially corresponding to said second power flux value by updating at least one preselected state parameter (4).

7. The method of claim 6,

-estimating a first power flux value (6) for the power flux at least one point (5) in the transport system using the power model;

-a second power flux value (7) corresponding to the first power flux value (6) is derived from the second input parameter for the power flux at the aforementioned at least one point in the transport system;

-configuring at least one status parameter (4) of the transport system based on a deviation (8) between the aforementioned first and second power flux values.

8. The method of claim 7,

-the value of at least one state parameter (4) is configured such that the aforementioned first power flux value (6) is thereby modified towards the aforementioned second power flux value (7).

9. Method according to claim 7, characterized in that at least one of said parameters (2, 3, 4) comprises a number of mutually consecutive parameter elements, and that at least one of said first (6) and said second (7) power flux values comprises a number of mutually consecutive power values corresponding to the parameter element values.

10. Method according to any of the preceding claims 6-7, characterized in that the gain G and/or zero offset O of the car load weighing device of the elevator system is determined by using the power model.

11. Method according to claim 10, characterized in that the car load weighing device is monitored by short-term and/or long-term monitoring of changes occurring in the gain G and/or zero offset O of the car load weighing device for detecting fault situations and/or for determining maintenance requirements.