Elevator operation profile adaptation method

Abstract

An elevator system comprises an elevator car and a drive unit comprising a drive pulley and a motor arranged to move the elevator car according to a predetermined operating profile. The elevator system also includes one or more power sources for providing power to the drive unit, a current sensor, and a controller. The controller is configured to cause the current sensor to measure a current through the motor while the elevator car is held stationary at the landing by the motor and / or during an initial phase of the operational profile to determine an available power from the one or more power sources, and determining a predicted power demand for the drive unit based on the measured current and one or more parameters of the predetermined operating profile. The controller is further configured to determine whether the predicted power demand is greater than available power from the one or more power sources and, if so, adjust one or more parameters of the predetermined operational profile while the elevator car is held stationary at the landing by the motor and / or during the initial phase.

Description

Technical Field

[0001] The present disclosure relates generally to elevator systems and methods of operating elevator systems, and more particularly, but not exclusively, to methods of adjusting operating profile parameters of elevator cars based on power availability in the elevator system. Background Art

[0002] Conventional elevator systems are supplied with power using a three-phase power supply from a local power grid. In such systems, the power available from the grid typically exceeds the power required by the elevator system in any given state. Therefore, a maximum power limit is set based on the electrical ratings of the components in the elevator system (e.g., the maximum current limit of the drive unit of the elevator system) rather than on the power available to the system from the power supply. In operation of such a system, the power to the elevator system depends only on whether the grid to which the system is connected is operational.

[0003] In the event that power is not available from the grid, the elevator system draws more power than is available from the grid to which it is connected. If an elevator car of the system is being driven to move when this occurs, the motor driving the elevator car stops functioning and the elevator car is caused to perform an emergency stop to ensure the safety of any passengers in the elevator car.

[0004] An example of this is shown in FIG1 , which shows a graph of available power versus time for use by a drive unit of an elevator system in FIG1( b ), and a graph of the speed of the elevator car as measured by an encoder in FIG1( a ), and a graph of the acceleration applied by the drive unit to the elevator car to achieve the predetermined operating profile seen in FIG1( a ) in FIG1( c ). Each of FIG1( a )-FIG1( c ) is shown as covering an elevator car accelerating from a stationary position at a landing at time t0 and until acceleration at time t1 at which the elevator car is accelerated. PL The time frame of the subsequent movement of the elevator car when the power loss event occurs.

[0005] As can be seen in Figure 1, at time t PL Before a power loss event occurs at t, the elevator car is accelerated based on the initial phase of the operation profile (between t0 and t1) until the car reaches the target speed v1. The elevator car continues to move at the target speed v1 until at time t PL At this point, when the elevator car is caused to perform an emergency stop in response to the power loss event, the measured speed of the elevator car can be seen to decrease from v1 to zero. It should be noted that at time t PL No deceleration is seen in Figure 1(c) because this shows the acceleration applied to the elevator car by the drive unit, rather than the measured acceleration of the elevator car.

[0006] In contrast to the three-phase power supply described above, some elevator systems are supplied with power using a single-phase power supply received from a local power grid, which is supplemented with a battery connected to the elevator system. Such elevator systems can be implemented in areas where the local power grid is unreliable, as the provision of a battery allows the system to remain operational even when the grid is inoperable, such as during a power outage. Unlike more conventional three-phase elevator systems, the maximum power limit in a single-phase, battery-supplemented system is set based on the available power from the grid and the battery at any given time. Thus, in operation, the amount of power consumed by the elevator system, and more specifically by the drive unit, can be adjusted based on the level of available power.

[0007] For example, when power from the grid is not available, the system can switch to battery-only operation and the maximum power consumed by the system can be reduced, for example by reducing the speed at which the elevator car is moved by the drive unit. In this way, if power from the grid is lost, an emergency stop can be avoided by, for example, moving the elevator car at a lower speed using only power from the battery.

[0008] Although it is known to adjust the operating speed of an elevator car in response to a partial loss of power, existing methods are not well optimized and often result in an elevator car unnecessarily increasing flight time when maximum power supply is not available. Furthermore, existing methods often fail to operate when there is a high elevator car load.

[0009] The present disclosure aims to provide an improved elevator system and method of operating an elevator system which seeks to address at least some of the above-mentioned problems. Summary of the invention

[0010] According to a first aspect, there is provided an elevator system, comprising:

[0011] elevator cars; and

[0012] A drive unit, the drive unit comprising:

[0013] a drive pulley connected to the elevator car via a tension member; and

[0014] a motor arranged to rotate the drive pulley to move the elevator car according to a predetermined operating profile;

[0015] Wherein, the elevator system further comprises:

[0016] one or more power sources for providing power to the drive unit;

[0017] a current sensor arranged to measure a current through the motor, the current being representative of a torque applied by the motor to the drive pulley; and a controller configured to:

[0018] causing the current sensor to measure the current through the motor when the elevator car is held stationary at the landing by the motor and / or during an initial phase of the predetermined operating profile;

[0019] determining a predicted power demand of the drive unit based on the measured current and one or more parameters of the predetermined operating profile;

[0020] determining available power from the one or more power sources;

[0021] determining whether the predicted power demand is greater than the available power from the one or more power sources; and

[0022] If the predicted power demand is greater than the available power from the one or more power sources, one or more parameters of the predetermined operating profile are adjusted while the elevator car is held stationary at the landing by the motor and / or during the initial phase.

[0023] According to a second aspect, there is provided a method of operating an elevator system comprising an elevator car and a drive unit, the method comprising:

[0024] measuring, using a current sensor, a current through the motor of the drive unit while the elevator car is held stationary at the landing by the motor and / or during an initial phase of the predetermined operating profile, wherein the current represents a torque applied by the motor to a drive pulley connected to the elevator car via a tension member;

[0025] determining a predicted power demand of the drive unit based on the measured current and one or more parameters of a predetermined operating profile of the elevator car;

[0026] determining available power from the one or more power sources;

[0027] determining whether the predicted power demand is greater than the available power from the one or more power sources; and

[0028] If the predicted power demand is greater than the available power from the one or more power sources, one or more parameters of the predetermined operating profile are adjusted while the elevator car is held stationary at the landing by the motor and / or during the initial phase.

[0029] Thus, it will be seen that, according to the present disclosure, the predicted power demand of the drive unit of the elevator system is determined based on the current measured through the motor of the drive unit when the elevator car is held stationary at a landing by the motor and / or during the initial phase of a predetermined operating profile, which current represents the torque applied to the drive pulley by the motor. Based on the measured current, a determination is then made as to whether the predicted power demand is greater than the available power from one or more power sources providing power to the drive unit, i.e., whether the available power will be exceeded if the elevator car moves according to the predetermined operating profile. If the predicted power demand is greater than the available power from the one or more power sources, one or more parameters of the operating profile are adjusted during the initial phase of the operating profile. It will be understood that the "initial phase" of the operating profile may include a period of time before the elevator car enters the constant speed phase of the operating profile. For example, it may include the time when the elevator car accelerates away from the landing until a constant target speed is reached.

[0030] By adjusting one or more parameters of a predetermined operating profile based on a determination that the available power will be exceeded, the predetermined operating profile can be pre-adjusted to ensure that the power consumed by the elevator system will not be greater than the available power during a subsequent stage of the operating profile. This can allow for avoiding emergency stop operations caused, for example, by excessive loads in the elevator car or significant shortages of available power from one or more power sources. For example, the controller can determine, based on the measured current, that the load in the elevator car requires a reduction in the speed and / or acceleration of the elevator car to prevent the amount of power used by the drive unit from exceeding the available power from the one or more power sources. Thus, in some examples, the controller can be configured to cause the drive unit to move the elevator car according to the adjusted operating profile by causing the motor to rotate a drive pulley.

[0031] Furthermore, making the determination that the available power will be exceeded based on the current measured when the elevator car is held stationary at a landing by the motor and / or during an initial phase of the operating profile means that the parameters of the subsequent phases of the operating profile can be adjusted for each individual trip performed by the elevator car depending on, for example, the load in the elevator car and the direction of travel. This can allow reducing the trip time compared to existing methods, in particular in the case of low car loads.

[0032] In some examples, the controller may be configured to cause the current sensor to measure the current through the motor when the elevator car is kept stationary at the landing by the motor (i.e., before the car moves away from the landing). When the elevator car is kept stationary by the motor, the current through the motor generates a torque that counteracts the torque on the drive pulley caused by the load of the elevator car. Therefore, when the current through the motor is measured while the elevator car is kept stationary by the motor, the current represents the load in the elevator car. Therefore, the controller may adjust some parameters of the predetermined operating profile based on the load in the elevator car. In some such examples, the controller may be configured to adjust one or more parameters of the predetermined operating profile when the elevator car is kept stationary at the landing by the motor, i.e., before the elevator car leaves the landing. This can ensure that the load in the elevator car is taken into account in the adjusted operating profile before increasing the power required by the drive unit to move the elevator car away from the landing. This may include adjusting the parameters of the maximum jerk and / or maximum acceleration in the predetermined operating profile before the elevator car leaves the landing.

[0033] In some examples, additionally or alternatively, the controller may be configured to adjust one or more parameters of the run profile during an initial phase of the predetermined run profile. This may include adjusting parameters of maximum jerk and / or maximum acceleration and / or constant target speed in the predetermined run profile when the elevator car moves during the initial phase.

[0034] In some examples, in addition to or as an alternative to causing the current value to be measured when the elevator car is stationary at the landing, the controller can be configured to cause the current sensor to measure the current through the motor during the initial stage of the operating profile. For example, the controller can be configured to cause the current sensor to measure the current through the motor during the initial stage of the predetermined operating profile, i.e., any time before the elevator car reaches a constant target speed. In some such examples, the controller can be configured to cause the current sensor to measure the current through the motor during the initial acceleration of the elevator car leaving the landing. In some other examples, the controller can be configured to cause the current sensor to measure the current through the motor during the period of reduced acceleration of the elevator car as it approaches the constant target speed.

[0035] The controller may be configured to determine the available power of the drive unit based on corresponding inputs (e.g., electrical signals, such as voltage and / or current) received from one or more power sources, the corresponding input indicating that the power source from which the input is received is operable. As an example, in the case where the one or more power sources include a first power source and a second power source, the controller may receive a first input and / or a second input from the first power source and the second power source, respectively, indicating that the first power source and / or the second power source are operable. When the controller receives input only from the first power source, the controller may determine that the first power amount is available for the drive system. When the controller receives input only from the second power source, the controller may determine that the second power amount is available for the drive system. When the controller receives input from both the first power source and the second power source, the controller may determine that a third power amount (e.g., equal to the sum of the first power amount and the second power amount) is available for the drive system. It will be appreciated that although the above example describes a system with two power sources, this is purely exemplary, and in some examples, the number of power sources may be less than or more than that number.

[0036] When the elevator car is moved away from a landing by the motor during an initial phase of a predetermined operating profile, the current through the motor generates a torque that counteracts the torque on the drive pulley generated not only by the load in the elevator car but also by the inertia of the elevator car and the friction in the elevator shaft. Thus, measuring the current through the motor when the elevator car is moved away from a landing during an initial phase of a predetermined operating profile may allow the effects of imbalance and / or inertia and / or friction to be taken into account when adjusting the parameters of the operating profile.

[0037] In some examples, the one or more power sources may include a source of AC power. In some examples, the source of AC power may include a connection to a power grid. The connection may be via a direct connection to the power grid (e.g., 480V, three-phase line voltage), or may be a connection via a power outlet in the building where the elevator system is located, e.g., a connection to a 230V single-phase line voltage.

[0038] In addition to or as an alternative to a source of AC power, in some examples, one or more power sources may include a battery. The use of a battery may allow the elevator system to operate even when power from a local power grid is unavailable. The battery may include a battery pack comprising a plurality of batteries connected in series. In examples where one or more power sources include a battery, the system may include an inverter for converting the DC power supplied by the battery into a three-phase AC power for use by the motor. In some examples, the inverter may be included in the drive unit, for example, in a regenerative drive of the drive unit.

[0039] In an example where the elevator system is connected to a power grid via a power outlet in a building in which the elevator system is located, one or more power sources may include a single-phase power supply. In such an example, the elevator system may include a converter for converting the single-phase AC power supply to DC power, which in some examples may be used to charge a battery of the elevator system. In some such examples, the elevator system may include an inverter for converting the DC power to three-phase power to supply power to the motor. In some examples, the inverter may be included in the drive unit, such as in a regenerative drive of the drive unit.

[0040] In some examples, the controller can be configured to determine whether the available power from one or more power sources has decreased by more than a threshold value. For example, the controller can determine that one or more of the one or more power sources are inoperable. This may be particularly important in a system where one or more power sources include a source of AC power (e.g., a connection to a power grid) in addition to a battery, because it may indicate that the AC power source and / or the battery cannot supply power to the elevator system. If, for example, a determination is made that the available power has decreased by more than a threshold value before the elevator car moves away from the landing, the controller can adjust one or more parameters of a predetermined operating profile based on the determination. This adjustment may allow the elevator system to continue operating even when one of the sources of AC power or the battery is unavailable.

[0041] The parameters of the predetermined operating profile (hereinafter referred to as operating profile parameters) can define the manner in which the elevator car is controlled to move between landings. In some examples, the operating profile parameters can define one or more of the speed, acceleration, and jerk of the elevator car when it moves from a departure landing to a destination landing during its operation between landings according to the predetermined operating profile.

[0042] In some examples, the operating profile parameters may define a time series of speed, acceleration, and / or jerk values ​​describing the movement of the elevator car. For example, the operating profile parameters may include a time series of speed and / or acceleration and / or jerk values ​​of the elevator car as it moves from a departure landing to a destination landing during its operation between landings.

[0043] The operation of the elevator car between landings may include a first "jump in" phase, in which the elevator car is accelerated from zero acceleration to a predetermined maximum acceleration value, and a first "jump out" phase, in which the acceleration is reduced from the maximum acceleration value to zero. After the first jump out phase, the elevator car may travel at a constant target speed until it approaches the destination landing. At this point, a second "jump in" phase may be initiated, in which the elevator car is decelerated from zero deceleration to a predetermined maximum deceleration value. Finally, a second "jump out" phase may be initiated, in which the deceleration is reduced from the maximum deceleration value to zero, and the speed of the elevator car may also be reduced to zero, so that the car stops at the destination landing.

[0044] Thus, in some examples, one or more parameters of the predetermined operating profile may include a constant target speed of the elevator car. The constant target speed may be a maximum speed of the elevator car during operation between landings. The constant target speed may be a constant speed of the car after accelerating away from a departure landing and before decelerating when approaching a destination landing. In some examples, the controller may be configured to adjust the constant target speed of the elevator car when the elevator car is moving during an initial phase.

[0045] In some examples, one or more parameters of the predetermined operating profile may include an acceleration of the elevator car. The acceleration may be a maximum acceleration of the elevator car during operation between landings. The controller may be configured to adjust the maximum acceleration of the elevator car when the elevator car is held stationary at a landing by the motor and / or when the elevator car is moving during an initial phase.

[0046] In some examples, one or more parameters of the predetermined operating profile may include a jerk of the elevator car during operation between landings, such as a maximum jerk of the elevator car during operation between landings. The controller may be configured to adjust the maximum jerk of the elevator car when the elevator car is held stationary at a landing by the motor and / or when the elevator car is moving during an initial phase.

[0047] In some examples, the controller can be configured to adjust the maximum acceleration and / or maximum jerk of the elevator car at a first time during an initial phase, and subsequently adjust the constant target speed of the elevator car at a second time later during the initial phase. The first time can be, for example, during an initial acceleration of the elevator car leaving a landing. The second time later of the constant target speed can be, for example, during a constant acceleration period of the elevator car.

[0048] In some examples, the operating profile parameters may include multiple time series of speed, acceleration and / or jerk values. For example, the operating profile parameters may include corresponding time series of speed, acceleration and jerk values ​​associated with different stages of the operating profile. In some such examples, the operating profile parameters may include a time series of jerk values ​​associated with the first "rapid in" stage, and / or a time series of jerk values ​​associated with the first "jump out" stage, and / or a time series of jerk values ​​associated with the second "rapid in" stage, and / or a time series of jerk values ​​associated with the second "jump out" stage. In some examples, the operating profile parameters may include a first time series of acceleration values ​​for each of the acceleration and deceleration stages of a predetermined operating profile.

[0049] In some examples, acceleration and / or jerk parameters may be adjusted when the elevator car is stationary at a landing, and speed parameters may be dynamically adjusted during an initial phase of a predetermined operating profile (e.g., as the elevator car moves away from a departure landing).

[0050] In some examples, the motor may be a three-phase AC synchronous or asynchronous motor. However, it will be appreciated that in some examples, alternative motor types may be used, such as a single-phase motor.

[0051] In some examples, the controller may be part of an elevator control system. The controller may include a general purpose processor that executes a computer program stored on a storage medium, the computer program including instructions for performing the method of the second aspect. In some examples, the predetermined operating profile may be stored in a memory accessible by the controller.

[0052] The current through the motor can be measured by a current sensor by detecting the current flowing into or out of the motor from one or more power sources. In some examples, a Hall effect sensor or a shunt resistor can be used to measure the current through the motor.

[0053] Features of any aspect or example described herein may be applied to any other aspect or example described herein in any appropriate circumstances. When referring to different examples or sets of examples, it should be understood that these examples are not necessarily different, but can be overlapping. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Certain examples of the present disclosure will now be described with reference to the accompanying drawings, in which:

[0055] FIG. 1 illustrates prior art for (a) elevator car speed according to a predetermined operating profile, (b) available power, and (c) elevator car acceleration according to the available power and the predetermined operating profile;

[0056] Figure 2An elevator system according to an example of the present disclosure is shown;

[0057] Figure 3 is a flow chart illustrating a method of operating an elevator system according to an example of the present disclosure;

[0058] Figure 4 is a flow chart illustrating a method of operating an elevator system according to an example of the present disclosure;

[0059] Figure 5 shows the power used by the elevator system and the elevator car speed for a range of elevator car loads according to a basic approach;

[0060] Figure 6 shows power used by an elevator system and elevator car speed for a range of elevator car loads when a method of operating an elevator system according to examples of the present disclosure is implemented; and

[0061] Figure 7 An adaptation of parameters of an elevator operating profile in an elevator system according to an example of the present disclosure is shown. DETAILED DESCRIPTION

[0062] Figure 2 A schematic overview of an elevator system 100 according to an example of the present disclosure is shown. The elevator system 100 includes an elevator car 101 and a counterweight 103, which are connected by tension members 102, which extend over a drive pulley 105 of a drive unit 109 and a diverting pulley 107 located between the drive pulley 105 and the elevator car 101. The drive unit 109 includes a motor 111 and a regenerative drive 112. A controller 123 is operably connected to the drive unit 109.

[0063] The drive pulley 105 is rotated by a three-phase motor 111 of a drive unit 109 to move the tension member 102 and thereby the elevator car 101 in the hoistway, as is known in the art. The drive unit 109 includes a current sensor 113 and a friction brake (shown in FIG. 1 for simplicity of illustration). Figure 2 101 ), the current sensor 113 is configured to measure the current through the motor 111 in use, and the friction brake can be used to selectively apply a braking force to resist the rotation of the drive pulley 105. This can be performed for one or more reasons, such as due to the load of the elevator car 101. The friction brake can be used to apply a braking force to hold the elevator car 101 at the landing of the building or to slow the movement of the elevator car 101.

[0064] The motor 111 is supplied with power using a single-phase power supply 115 as a first power source and a battery 117 as a second power source. In this example, the two power sources 115, 117 are connected to the motor 111 via a regenerative drive 112. The single-phase power supply 115 is provided by a connection to a fused socket in the building where the elevator system 100 is located, and is capable of providing 2kW±10% of power to the elevator system 100. The battery 117 comprises a group of 8 batteries connected in series, each battery being capable of providing 1kW±10% of power to the elevator system 100, provided that the battery 117 is within its normal operating parameters, for example when the temperature of the battery 117 is within a predetermined range. This means that when both the battery 117 and the single-phase power supply 115 are fully operational, the maximum power available to the elevator system 100 is 10kW±10%.

[0065] In order to enable the controller 123 to determine the amount of power available to the elevator system 100, in this example, the controller 123 is configured to receive inputs, such as current / voltage, from each of the battery 117 and the single-phase power supply 115 when the battery 117 and the single-phase power supply 115 are operable, i.e., capable of providing power to the drive system 109. Based on the input(s) received from the battery 117 and / or the single-phase power supply 115, the controller 123 determines the power available to the drive system 109. When only the single-phase power supply 115 is operable, the controller 123 determines that 2 kW ± 10% of the power is available to the drive unit 109. When only the battery 117 is operable, the controller 123 determines that 8 kW ± 10% of the power is available. When both the battery 117 and the single-phase power supply 115 are operable, the controller determines that 10 kW ± 10% of the power is available to the drive unit 109.

[0066] In some examples, the controller 123 can be configured to more accurately determine the amount of power available to the elevator system 100 by taking into account one or more external factors. For example, when the battery 117 is outside of its normal operating parameters, for example, when the temperature of the battery 117 is above / below a limit, the input from the battery 117 to the controller 123 can indicate that the battery is outside of its normal operating parameters and that the available power is reduced as a result. In this case, the controller can determine that a reduced amount of power (e.g., 6kW±10%) from the battery 117 is available to the drive unit 109.

[0067] In order to provide power from the single-phase power supply 115 to the three-phase motor 111 of the drive unit 109, the regenerative drive 112 of the drive system 109 includes an AC / DC converter 121 that converts the single-phase AC power from the single-phase power supply 115 into DC power that is provided to a DC bus 118 of the regenerative drive 112. The DC bus 118 outputs to an inverter 119 that converts the DC power from the DC bus 118 into three-phase AC power for the motor 111 of the drive unit 109.

[0068] In order to provide power from the battery 117 to the three-phase motor 111 of the drive unit 109, the drive unit 109 includes a DC / DC converter 116 that receives power from the battery 117 as input and outputs to a DC bus 118 of the regenerative drive 112. The DC bus 118 outputs to an inverter 119 that converts the DC power from the DC bus 118 to three-phase AC power for the motor 111 of the drive unit 109. The battery 117 can be charged using a single-phase power supply 115 via the DC bus 118 and the DC / DC converter 116. The battery 117 can also be charged using the regenerative power delivered to the battery 117 from the motor 111 via the inverter 119, the DC bus 118, and the DC / DC converter 116.

[0069] exist Figure 2 In the elevator system 100 shown in , the available power supply may vary, for example, depending on the grid availability via the single-phase power supply 115 and / or the charge level of the battery 117. For example, if the single-phase power supply 115 becomes unavailable, such as during a local grid blackout, only 8 kW ± 10% of the power is available to the elevator system 100 via the battery 117.

[0070] Similarly, if there is a problem with the battery 117, only 2 kW ± 10% of the power from the single-phase power supply 115 is available to the elevator system 100. When the available power decreases more than a threshold, such as when one of the battery 117 or the single-phase power supply 115 is inoperable, the controller 123 of the elevator system 100 is configured to adjust the operation of the drive unit 109 to ensure that the elevator system 100 maintains functionality, as will be explained in more detail below.

[0071] Controller 123 is configured to control the movement of elevator car 101 by providing appropriate instructions to drive unit 109. More specifically, controller 123 provides instructions to drive unit 109 to control motor 111 to move elevator car 101 between landings of a building where elevator system 100 is located.

[0072] The motor 111 is controlled by the controller 123 to move the elevator car 101 according to a predetermined operating profile (e.g., including an initial (acceleration) phase, a constant speed phase, and a deceleration phase). Before the acceleration phase, the elevator car 101 remains stationary at a landing (e.g., a departure landing). In the acceleration phase, the elevator car is accelerated away from the landing by the motor 111 until it reaches a target speed. After the acceleration phase, the motor 111 causes the elevator car 101 to continue moving at the target speed in the constant speed phase until it approaches the destination landing, at which point the friction brake is applied after the deceleration phase so that when the elevator car 101 reaches the destination landing, the speed of the elevator car 101 is reduced to zero.

[0073] The acceleration and speed of the elevator car 101 during a predetermined run profile are defined within the run profile by a set of run profile parameters that can be adjusted based on the power available to the elevator system 100. The run profile parameters include, but are not limited to, elevator car 101 acceleration, speed, and jerk.

[0074] In a first example, the elevator car 100 moves according to predetermined operating profile parameters, as described below with reference to Figure 3 As explained, Figure 3 A flow chart is shown illustrating a method of operating an elevator system 100 according to an example of the present disclosure.

[0075] In step 301 , the elevator car 101 is held at a landing using the motor 111 such that current flows through the motor 111 to generate a torque that counteracts the torque on the drive pulley 105 caused by the load of the elevator car 101 .

[0076] With the elevator car 101 held stationary at the landing, the current through the motor 111 is measured using the current sensor 113 in step 303. Since the current through the motor 111 generates a torque that counteracts the torque produced by the load of the stationary elevator car 101, the measured current represents the load in the elevator car 101 when the elevator car 101 is held stationary at the landing.

[0077] In step 305, the current measurement is provided to the controller 123, which determines the predicted power demand of the drive unit 109 of the elevator system 100 based on the measured current (and therefore the load in the elevator car 101), while the elevator car 101 is held stationary at the landing by the motor.

[0078] In step 307 , the controller 123 compares the predicted power demand to the amount of power available to the drive unit 109 , which is determined based on the input(s) of the single-phase power supply 115 and the battery 117 received at the controller 123 .

[0079] If the predicted power demand is less than the power available to drive unit 109, the process continues to step 308 where controller 123 causes drive unit 109 to move elevator car 101 according to a standard (eg, unregulated) predetermined operating profile.

[0080] However, if the predicted power demand is greater than the amount of power available to the drive unit 109 from the battery 117 and the single-phase power supply 115 , the process continues to step 309 .

[0081] In step 309, when the elevator car 101 is stationary at the landing via the motor 111, the controller 123 adjusts one or more parameters of the predetermined operating profile to reduce the power demand of the drive unit 109 during the elevator operation. For example, the controller 123 adjusts one or more of the acceleration, speed, or jerk of the elevator car 101 to reduce the maximum power demand of the drive unit 109 in subsequent operations.

[0082] Once the controller 123 has adjusted the parameters of the operating profile to reduce the peak power demand of the drive unit 109, in step 311 the controller 123 causes the drive unit 109 to move the elevator car 101 according to the adjusted operating profile.

[0083] By adjusting one or more operating profile parameters based on the current through the motor 111 before the elevator car 101 moves away from the departure landing, the peak power consumed by the elevator system 100 (and more specifically by the drive unit 109) can be reduced in advance so that it will be no greater than the power available to the elevator system 100 during subsequent operation from the single-phase power supply 115 and the battery 117. Furthermore, by determining the predicted power demand based on the current through the motor 111, which is representative of the motor torque when the elevator car 101 remains stationary at the landing and therefore represents the load in the elevator car 101, the use of less reliable equipment, such as an elevator car weighing system, can be advantageously avoided.

[0084] Additionally or alternatively, to determine whether the operating profile parameters need to be adjusted based on the predicted power demand determined from the measured current when the elevator car 101 remains stationary at the landing, the operating profile parameters can be adjusted based on the current through the motor 111 measured by the current sensor 113 when the elevator car 101 is moving. More specifically, the current through the motor 111 can be measured during the initial stage of the predetermined operating profile, and the adjusted operating profile parameters can be determined in response to the measured current value. Figure 4 An example of this situation is shown in Figure 4A flow chart is shown illustrating a method of operating an elevator system 100 according to the present disclosure that is performed when an elevator car 101 moves away from a landing during an initial phase of a predetermined run profile.

[0085] In step 401, the elevator car 101 is moved away from the departure landing using the motor 111.

[0086] In step 403, as the elevator car 101 accelerates away from the landing, the current through the motor 111 is measured using the current sensor 113. Since the current through the motor 111 is required to generate the torque to accelerate the elevator car 101, the measured current in motion represents not only the load in the elevator car 101, but also the inertia of the elevator car 101 and the friction in the elevator shaft.

[0087] In step 405 , the current measurement is provided to the controller 123 , which determines a predicted power demand of the drive unit 109 of the elevator system 100 based on the measured current.

[0088] In step 407, the controller 123 compares the predicted power demand to the power available to the drive unit 109, which is determined based on the input(s) of the single-phase power supply 115 and the battery 117 received at the controller 123. If the predicted power demand is less than the power available to the drive unit 109, the process continues to step 408, where the controller 123 causes the drive unit 109 to move the elevator car 101 according to the operating profile that was set before the elevator car 101 left the departure landing. However, if the predicted power demand is greater than the amount of power available to the drive unit 109 from the battery 117 and the single-phase power supply 115, the process continues to step 409.

[0089] In step 409, the controller 123 adjusts one or more parameters of the operating profile to reduce the power demand of the drive unit 109 during the subsequent phase of the operating profile. For example, the controller 123 may adjust one or more of the acceleration, speed, or jerk values ​​of the operating profile to reduce the maximum power demand of the drive unit 109.

[0090] Once the controller 123 has adjusted the parameters of the operating profile to reduce the peak power demand of the drive unit 109, in step 411, the controller 123 causes the drive unit 109 to move the elevator car 101 according to the adjusted operating profile.

[0091] By measuring the current through the motor 111 during an initial phase of a predetermined operating profile (e.g., when the elevator car 101 accelerates away from a departure landing in the initial phase of the operating profile), the predicted power demand of the elevator system 100 (and more specifically the predicted power demand of the drive unit 109) can be determined more accurately than based solely on measurements performed while the elevator car 101 remains stationary at a landing via the motor 111. Based on this improved prediction, operating profile parameters can be adjusted to achieve improved flight time, while still ensuring that the amount of power consumed by the drive unit 109 does not exceed the available power, compared to adjustments based solely on measurements performed while the elevator car 101 remains stationary at a landing.

[0092] Figure 5 The peak power consumed by the drive unit of the elevator system (curve 501) and the speed of the elevator car (curve 503) in the constant speed phase of a predetermined operating profile for a range of elevator car loads are shown for a system in which the operating profile parameters are adjusted according to a basic method used as a basis for the present disclosure. More specifically, the operating profile parameters are adjusted to a "quasi-static" profile by a simple method, which aims to run a full speed profile in regenerative operation and a reduced speed profile in motor-driven operation above 20% car load. Here, each motor-driven operation starts at a full speed profile (1000 mm / s). -1 ), but once the current in the motor 111 indicates that the motor drive torque is required to drive the elevator car, it switches to the lowering profile (180mm -1 ).

[0093] exist Figure 5 In the embodiment, power is only provided to the elevator system 100 by the single-phase power supply 115, i.e. the battery 117 is not available. Therefore, only 2 kW ± 10% of power is available for the drive unit 109 of the elevator system 100.

[0094] It can be seen that when the quasi-static operating profile is adopted, the elevator car 101 is made to move at a speed of 1000 mms / s for an elevator car load of 20% or less of the maximum load during the constant speed phase of the operating profile. -1 Move. Acceleration is always set to 0.2ms -2 And the jerk is set to 0.2ms -3 In order to reduce the peak power consumption of the elevator system 100 .

[0095] For car loads of 30% or more, it can be seen that as a result of adjustments to the run profile parameters, the speed of the elevator car 101 is reduced to 180 mms in the constant speed phase of the run profile. -1 In this way, the total power required by the elevator system 100 can be reduced so that even Figure 3In the reduced power scenario shown in , car loads up to 100% of the maximum car load can also be accommodated. If the method of the present disclosure is not used to adjust the parameters of the operating profile based on the measured car load, the power demand of the drive unit 109 will exceed the available power for the lower car load, so that the elevator system 100 can only operate for loads up to the lower car load.

[0096] Figure 6 6 shows the peak power consumed by the drive unit 109 of the elevator system 100 (curve 601) and the resulting speed of the elevator car 101 (curve 603) for a range of elevator car loads during the constant speed phase of the run profile for a system in which the run profile is adjusted according to the present disclosure. More specifically, Figure 6 In the operation profile shown in , the predetermined operation profile parameters are adjusted to a "dynamic" profile, wherein the elevator system 100 is configured to measure the current through the motor 111 while the elevator car 101 is held at the landing by the motor 111 and during the initial stage of the operation profile. More specifically, the current through the motor 111 is also measured during the acceleration of the elevator car 111 away from the landing, as described above with respect to Figure 4 Thus, the predicted power demand is determined based on current values ​​measured when the elevator car is stationary at a landing and during an initial phase of the operating profile.

[0097] First, an estimate of the holding power required for the load in the elevator car is made based on the current measured when the elevator car is stationary. Secondly, an estimate of the power required to generate torque in the motor to move the elevator car in the initial phase of the operating profile is then made based on the measured current in the initial phase.

[0098] The electrical power required to move the elevator car 101 to the operating profile is approximately equal to the mechanical power required to move the elevator car 101. In practice, the electrical power required is greater than the mechanical power due to efficiency losses, and a multiplier is used to account for this efficiency loss when determining the electrical power required to drive the elevator car 101 to the operating profile. The mechanical power P M = P M=τω. The angular velocity ω of the run profile may be calculated based on the speed of the elevator car 101 during the run profile and the radius of the drive pulley 105. Thus, the power required by the drive unit 109 during the main part of the run profile may be estimated based on the product of the torque measured during the initial phase of the run profile and the expected angular velocity based on the target constant speed of the elevator car 101 set in the run profile. Thus, the estimated power required by the drive unit 109 is extrapolated for the remaining part of the run based on the predetermined run profile parameters and the measured torque in the initial phase to determine the total predicted power requirement.

[0099] The total predicted power demand is then compared to the available power. If the total predicted power demand is greater than the available power, the parameters of the predetermined operating profile are adjusted.

[0100] As in Figure 5 In the example shown in , power is provided to the elevator system 100 only by the single-phase power supply 115, i.e. the battery 117 is not available. Figure 6 In the example shown in , only 2 kW ± 10% of the power is available for the drive unit 109 of the elevator system 100 .

[0101] It can be seen that when the dynamic operating profile is adopted, depending on the load in the elevator car 101, the elevator car 101 is made to move at a speed of 1000 mms / s in the constant speed phase of the operating profile. -1 and 140mms -1 It can be seen that the dynamic operation profile has been adapted so that when Figure 5 When compared to the quasi-static profile shown in for car loads between 30% and 90% of maximum load, increased speed is achieved without the elevator system 100 consuming more power than available from the single-phase power supply 115 .

[0102] exist Figure 7 An example of adjusting operating profile parameters in a reduced power scenario is shown in FIG. Figure 7 The change in the operating profile of the elevator car 101 with the greatest load is shown.

[0103] Figure 7 (a) and Figure 7 The graphs in (b) show velocity and acceleration, respectively, of an elevator car 101 implementing a 'standard' (eg, unregulated) predetermined operating profile with maximum car load and full power (10 kW ± 10%) available from the battery 117 and single phase power supply 115 .

[0104] It can be seen that the unadjusted operating profile includes 0a and t 1a The initial phase between1a and t 2a The constant speed phase between the two phases, in which the elevator car 101 accelerates from a stationary position at the departure landing to a speed of 800 mms -1 In this constant speed phase, the elevator car 101 continues to move at a speed of 800 mms -1 Finally, the operational profile consists of 2a and t 3a There is a deceleration phase between the elevator cars 101 and the destination landing, during which the speed of the elevator car 101 is reduced to zero when it reaches the destination landing.

[0105] Figure 7 (c) and Figure 7 The graphs in (d) show the speed and acceleration of the elevator car 101 with maximum car load, respectively, when only power from the battery 117 is available (i.e., where only 8 kW ± 10% of the available power is present). Figure 6 The dynamic profile described is used to adjust the operating profile.

[0106] exist Figure 7 As can be seen in (d), when the dynamic profile is applied, Figure 7 Compared to the full power case shown in (b), t 0b and t 1b The maximum acceleration during the initial stage is from 500mms -2 Reduced to 300mms -2 , and the deceleration from the maximum acceleration is prolonged over time, i.e., in response to the reduced amount of available power, the first rush-out phase of the operating profile is prolonged. The acceleration rush-out is the most power-intensive part of the operating profile, and by prolonging its duration, the power consumption of the drive unit 109 can be significantly reduced.

[0107] As a result of the adjustment of the acceleration and jerk parameters of the run profile, it can be seen that the speed of the elevator car 101 increases more slowly than if both the battery 117 and the single-phase power supply 115 were fully functional, and it can also be seen that the run profile increases at t 1b and t 2b The duration of the constant speed phase between Figure 7 As can be seen in (c), despite the fact that only battery power is available, due to the adjusted operating profile parameters, the elevator car 101 is still able to achieve a constant speed that is the same as the constant speed achieved when both the battery 117 and the single-phase power supply 115 are available (as shown in curves 701a, 702a), and no emergency stop operation is required even at maximum car load.

[0108] Thus, by adjusting the operating profile parameters of the elevator car 101 in response to the predicted power demand of the drive unit 109, for example, by extending the duration of the first emergency exit phase based on the measured current through the motor 111 being greater than the available power, the elevator system 100 can continue to operate efficiently even when the single-phase power supply 115 is unavailable. Figure 7 As can be seen in , the adjustment of the operating profile parameters allows a reasonable flight time to be achieved even when there is a maximum car load. Thus, predicting the power demand of the drive unit 109 based on the measurements of the current through the motor 111 performed when the elevator car 101 is stationary and during the initial phase of the operating profile ensures that the drive unit 109 will remain within the available power limits despite the reduced power availability and load in the elevator car 101.

[0109] Those skilled in the art will appreciate that the present disclosure has been illustrated by describing one or more specific examples thereof, but is not limited to these examples; numerous variations and modifications are possible within the scope of the appended claims.

Claims

1. An elevator system (100), comprising: Elevator car (101); as well as A drive unit (109), the drive unit (109) comprising: connected to a drive pulley (105) of an elevator car (101) via a tension member (103); and a motor (111) arranged to rotate the drive pulley (105) so as to move the elevator car (101) according to a predetermined operating profile; Wherein, the elevator system (100) further comprises: one or more power sources (115; 117) for providing power to the drive unit (109); a current sensor (113) arranged to measure a current through the motor (111), the current being representative of a torque applied by the motor (111) to the drive pulley (105); and A controller (123), wherein the controller (123) is configured to: causing the current sensor (113) to measure the current through the motor (111) when the elevator car (101) is held stationary at the landing by the motor (111) and / or during an initial phase of the predetermined operating profile; determining a predicted power demand of the drive unit (109) based on the measured current and one or more parameters of the predetermined operating profile; determining available power from the one or more power sources (115; 117); determining whether the predicted power demand is greater than the available power from the one or more power sources (115; 117); and If the predicted power demand is greater than the available power from the one or more power sources (115; 117), one or more parameters of the predetermined operating profile are adjusted while the elevator car (101) is held stationary at the landing by the motor (111) and / or during the initial phase.

2. The elevator system (100) according to claim 1, wherein: The controller (123) is configured to cause the current sensor (113) to measure the current through the motor (111) during the initial phase of the predetermined operating profile before the elevator car (101) reaches a constant target speed.

3. The elevator system (100) according to claim 2, wherein: The controller (123) is configured to cause the current sensor (113) to measure the current through the motor (111) during initial acceleration of the elevator car (101) away from the landing.

4. The elevator system (100) according to claim 2 or 3, wherein: The controller (123) is configured to cause the current sensor (113) to measure the current through the motor (111) during deceleration of the elevator car (101) as it approaches the constant target speed.

5. The elevator system (100) according to any one of the preceding claims, wherein: The one or more power sources (115; 117) include a connection to an electrical grid.

6. The elevator system (100) according to any one of the preceding claims, wherein: The one or more power sources (115; 117) include a battery (117).

7. The elevator system (100) according to any one of the preceding claims, wherein: The controller (123) is also configured to determine whether the available power from the one or more power sources (115; 117) has decreased by more than a threshold value.

8. The elevator system (100) according to claim 7, wherein: In response to determining that the available power from the one or more power sources has decreased by more than a threshold, the controller (123) is configured to adjust one or more parameters of the predetermined operating profile and cause the elevator car (101) to move according to the adjusted operating profile.

9. The elevator system (100) according to any one of the preceding claims, wherein: The one or more parameters include a constant target speed of the elevator car, a maximum acceleration of the elevator car, and a maximum jerk of the elevator car.

10. The elevator system (100) according to any one of the preceding claims, wherein: The controller (123) is configured to adjust the constant target speed of the elevator car (101) when the elevator car (101) is moving during the initial stage.

11. The elevator system (100) according to any one of the preceding claims, wherein: The controller (123) is configured to adjust the maximum acceleration of the elevator car (101) when the elevator car (101) remains stationary at the landing by the motor (111) and / or when the elevator car (101) moves during the initial stage.

12. The elevator system (100) according to any one of the preceding claims, wherein: The controller (123) is configured to adjust the maximum jerk of the elevator car (101) when the elevator car (101) remains stationary at the landing by the motor (111) and / or when the elevator car (101) moves during the initial stage.

13. The elevator system (100) according to any one of the preceding claims, wherein: The controller (123) is configured to adjust the maximum acceleration and / or maximum jerk of the elevator car (101) at a first time during the initial phase and subsequently adjust the constant target speed of the elevator car (101) at a second time later during the initial phase.

14. A method of operating an elevator system (100) comprising an elevator car (101) and a drive unit (109), the method comprising: measuring, using a current sensor (113), a current through a motor (111) of the drive unit (109) when the elevator car (101) is held stationary at the landing by the motor (111) and / or during an initial phase of the predetermined operating profile, wherein the current is representative of a torque applied by the motor (111) to a drive pulley (102) connected to the elevator car (101) via a tension member (104); determining a predicted power requirement of the drive unit (109) based on the measured current and one or more parameters of a predetermined operating profile of the elevator car (101); determining available power from the one or more power sources (115; 117); determining whether the predicted power demand is greater than the available power from the one or more power sources (115; 117); and If the predicted power demand is greater than the available power from the one or more power sources (115; 117), one or more parameters of the predetermined operating profile are adjusted while the elevator car (101) is held stationary at the landing by the motor (111) and / or during the initial phase.

15. The method according to claim 14, comprising measuring the current through the motor (111) of the drive unit (109) during the initial phase of the predetermined operating profile before the elevator car (101) reaches a constant target speed.

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