WO2018138403A1 - Method for controlling electrical input power of elevator, elevator control unit, computer program product, and elevator utilizing the method thereof - Google Patents

Method for controlling electrical input power of elevator, elevator control unit, computer program product, and elevator utilizing the method thereof Download PDF

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Publication number
WO2018138403A1
WO2018138403A1 PCT/FI2017/050036 FI2017050036W WO2018138403A1 WO 2018138403 A1 WO2018138403 A1 WO 2018138403A1 FI 2017050036 W FI2017050036 W FI 2017050036W WO 2018138403 A1 WO2018138403 A1 WO 2018138403A1
Authority
WO
WIPO (PCT)
Prior art keywords
elevator
electrical
electrical energy
energy storage
brake
Prior art date
Application number
PCT/FI2017/050036
Other languages
French (fr)
Inventor
Pasi Raassina
Original Assignee
Kone Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kone Corporation filed Critical Kone Corporation
Priority to PCT/FI2017/050036 priority Critical patent/WO2018138403A1/en
Publication of WO2018138403A1 publication Critical patent/WO2018138403A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
    • B66B1/00—Control systems of elevators in general
    • B66B1/24—Control systems with regulation, i.e. with retroactive action, for influencing travelling speed, acceleration, or deceleration
    • B66B1/28—Control systems with regulation, i.e. with retroactive action, for influencing travelling speed, acceleration, or deceleration electrical
    • B66B1/32—Control systems with regulation, i.e. with retroactive action, for influencing travelling speed, acceleration, or deceleration electrical effective on braking devices, e.g. acting on electrically controlled brakes
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • H02J9/062—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for AC powered loads
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • H02J9/08—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems requiring starting of a prime-mover
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B50/00—Energy efficient technologies in elevators, escalators and moving walkways, e.g. energy saving or recuperation technologies

Definitions

  • the invention concerns in general the technical field of elevators.
  • the invention concerns especially methods for controlling the electrical input power of an elevator.
  • Electrical power required for operating an elevator is typically drawn from an electrical power grid through an electrical supply connection of the elevator.
  • the elevator draws power at all times to match the required amount of power for operating the elevator car and energizing all components and sub-systems of the elevator.
  • These components and sub-systems typically include an electric motor, lighting equipment, safety equipment, an electrical drive, an elevator brake, etc.
  • Typical elevators utilize electro-mechanical brakes, which are operated so that electrical power is required to energize an electromagnet which then deactivates the brake by applying a force via magnetic field.
  • the deactivation of the brake consumes electrical energy. This typically happens when the elevator car of the elevator is moving or when the elevator car is about to be moved. Less or no power is consumed when the electro-mechanical brake is activated which happens so that, for example, a spring element pushes the brake into the activated state thus producing significant friction to decelerate, to stop or to keep the elevator car in its position.
  • a method for controlling electrical input power of an elevator relative to an operating state of the elevator comprises an elevator brake arrangement comprising an elevator brake and an electrical energy storage electrically coupled to the elevator brake.
  • the method comprises
  • the method may comprise keeping or maintaining the elevator brake deactivated by electrical energy from the electrical energy storage while simultaneously driving electric motor by electrical energy from the main electrical power supply connection of the elevator.
  • the method may comprise determining the operating state of the elevator based on at least electrical input power of the elevator. Alternatively or in addition, one or several other parameters may be taken into account such as position, speed, acceleration/deceleration or rate of acceleration/deceleration of the elevator car or the electric motor of the elevator for determining the operating state.
  • the charging may comprise charging the electrical energy storage by electrical power drawn from a main electrical power supply connection of the elevator.
  • the charging may comprise charging the electrical energy storage by electrical power generated by an electric motor of the elevator when the electric motor is being electrically decelerated, i.e., by regenerative electrical energy.
  • the charging may comprise charging the electrical energy storage through an intermediate circuit of an electrical drive or an input circuit of an inverter operating the electric motor of the elevator.
  • the deactivating may comprise deactivating the elevator brake by electrical power drawn from a main electrical power supply connection of the elevator, if a state-of-charge value of the electrical energy storage is lower than a predetermined state-of-charge threshold.
  • the deactivating may comprise deactivating the elevator brake by electrical power drawn from the electrical energy storage, if an electrical input power of an elevator is higher than a predetermined electrical input power threshold.
  • an elevator control unit for controlling electrical input power of an elevator.
  • the elevator comprises an elevator brake arrangement, wherein the elevator brake arrangement comprises an elevator brake and an electrical energy storage electrically coupled to the elevator brake.
  • the elevator control unit comprises at least one processor, and at least one memory storing at least one portion of computer program code. The at least one processor being configured to cause the elevator control unit at least to perform:
  • a computer program product comprising program instructions. Said instructions, when executed by an elevator control unit, cause the elevator control unit to perform the method according to the first aspect.
  • an elevator for controlling electrical input power of the elevator is provided.
  • the elevator brake arrangement comprises an elevator brake and an electrical energy storage electrically coupled to the elevator brake.
  • the elevator further comprises an elevator control unit configured to at least charge the electrical energy storage through an electrical connection of the elevator brake arrangement, and deactivate the elevator brake by electrical energy from the electrical energy storage.
  • the elevator control unit and the elevator brake arrangement are communicatively coupled to each other.
  • the present invention provides a method for controlling electrical input power of an elevator utilizing an electrical energy storage for deactivating the elevator brake.
  • the method provides advantages over known solutions such that the electrical input power of the elevator may be reduced by charging the electrical energy storage of the elevator brake arrangement when the elevator power demand is low or by utilizing regenerative power from the electric motor of the elevator, and then utilizing stored electrical energy in the electrical energy storage to deactivate the elevator brake, thus avoiding drawing the power from the electrical supply grid.
  • a plurality of refers herein to any positive integer starting from two, e.g. to two, three, or four.
  • the terms “first”, “second”, “third”, “fourth” and “fifth” do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.
  • FIG 1 illustrates schematically an elevator according to an embodiment of the present invention.
  • Figure 2 illustrates a flow diagram presenting an embodiment of a method in accordance with the present invention.
  • Figures 3A and 3B illustrate examples of the electrical drive in accordance with embodiments of the present invention.
  • FIGS 4A and 4B illustrate schematically embodiments of an elevator brake arrangement in accordance with embodiments of the present invention.
  • Figure 5 illustrates an elevator brake arrangement according to an embodiment of the present invention.
  • Figure 6 illustrates an elevator brake arrangement according to an embodiment of the present invention.
  • FIG. 7 illustrates schematically an elevator control unit according to an embodiment of the present invention. DESCRIPTION OF SOME EMBODIMENTS
  • FIG. 1 illustrates schematically an elevator 1000 according to an embodiment of the present invention.
  • the elevator 1000 may comprise an electric motor 155 for moving an elevator car 130 comprised in the elevator 1000.
  • the elevator car 130 may be mechanically coupled to the electric motor 155, for example, by a hoisting rope 140, hydraulic means or in more direct manner in case of a linear motor.
  • the operation of the electric motor 155 may be controlled by an electrical drive 105 such as a frequency converter or an inverter.
  • the hoisting rope 140 may comprise, for example, steel or carbon fibers.
  • the term 'hoisting rope' does not limit the form of the element anyhow.
  • the hoisting rope 140 may be implemented as a rope, a belt, or a track in ropeless or rope-free elevators.
  • the elevator 1000 may comprise an elevator control unit 1 100 for controlling the operation of the elevator 1000.
  • the elevator control unit 1 100 may be a separate device or may be comprised in the other components of the elevator 1000 such as in or as a part of the electrical drive 105.
  • the elevator control unit 1 100 may also be implemented in a distributed manner so that, e.g., one portion of the elevator control unit 1 100 may be comprised in the electrical drive 105 and another portion in the elevator car 130.
  • the elevator control unit 1 100 may also be arranged in distributed manner at more than two locations or in more than two devices.
  • the elevator 1000 may comprise an elevator brake arrangement 1 10 comprising an elevator brake 1 16, preferably, an electromechanical elevator brake 1 16.
  • the elevator brake arrangement 1 10 may be connected to an intermediate circuit of a frequency converter, an input circuit of an inverter or directly to the main electrical power supply connection 100 of the elevator 1000.
  • the elevator brake arrangement 1 10 may comprise an electrical converter 1 12 for converting voltage and/or current to suitable levels to operate the elevator brake arrangement 1 10. There may also be such an electrical converter 1 12 if the elevator brake arrangement 1 10 is connected to the intermediate circuit or the input circuit of the electrical drive 105.
  • the elevator 1000 may comprise, for example, as a part of the brake arrangement 1 10, a brake controlling unit for controlling the operation of the elevator brake 1 16, such as, to deactivate and/or activate the elevator brake 1 16.
  • the brake(s) 1 16 may operate such as the magnetization of the coils of the brake(s) 1 16 deactivates the brake(s) 1 16 by force applied via magnetic field.
  • the brake controlling unit may be integrated into the brake 1 16 or may be a separate brake controller device.
  • the electrical energy storage 1 14 may be used in normal operating conditions and/or in emergency conditions of the elevator 1000.
  • the normal operating conditions refer to conditions in which the elevator 1000 serves its landing floors in normal manner.
  • the emergency conditions refer to conditions in which there is, for example, a failure or loss of the main electrical power supply 125.
  • the emergency conditions may refer also to conditions in which the safety circuit of the elevator 1000 has been interrupted thus indicating conditions apart from the normal operating conditions.
  • the elevator brake arrangement 1 10 may comprise an electrical energy storage 1 14.
  • the electrical energy storage 1 14 may be connected to the intermediate circuit or the input circuit of the electrical drive 105, preferably, via the electrical converter 1 12 such as a voltage step-down converter.
  • the elevator brake arrangement 1 10 may also comprise a brake control unit or a part of the elevator control unit 1 100.
  • a main electrical power supply 125 such as a three- or single-phase electrical power grid
  • an electrical connection 120 of the elevator brake arrangement 1 10 connection means 165 between the electrical drive 105 and the electric motor 155.
  • the elevator car 130 may operate in a hoistway 145 serving landing floors 160.
  • the electric motor 155 may be a single-phase, two-phase or three-phase electric motor 155.
  • the electric motor 155 may be a permanent magnet motor such as a surface- mounted or an interior permanent magnet motor.
  • the electric motor 155 may be a linear, radial, axial, or transverse type of a motor.
  • a rotor of the permanent magnet motor has at least one permanent magnet providing magnetization of the rotor, i.e. excitation.
  • the electric motor 155 may be a synchronous motor comprising a magnetizing circuit or an exciter in connection with the rotor.
  • the electric motor 155 may be an asynchronous electric motor such as an induction motor, or a doubly-fed induction motor or an asynchronous slip ring motor capable of being excited externally via the slip ring, for example, via brushes or wirelessly such as by induction.
  • the excitation may be provided by, for example, a permanent magnet or a battery-operated exciter.
  • the excitation may be based on injecting direct current (DC) into a magnetization circuit of the rotor, thus magnetizing the rotor.
  • the exciter may be at least partly coupled to the rotor.
  • the elevator 1000 may have an auxiliary electrical power supply.
  • the auxiliary electrical power supply may be utilized, for example, in situations in which there is a failure of a main electrical power supply of the elevator 1000, such as failure in an electrical power grid having, for example, a fundamental frequency of 50 or 60 Hz, the elevator 1000.
  • the auxiliary electrical power supply may be an electrical supply grid other than the main electrical power supply or an electrical power source such as a gas turbine engine, an internal combustion engine or a fuel cell.
  • the auxiliary electrical power supply may be used to feed power to operate the electrical drive 105 as well as other components required to be operable during conditions without power available from the main electrical power supply.
  • the other components required to be operable may be, for example, part of the elevator controlling system, components of the elevator car 130, the magnetizing circuit or the exciter of the electric motor 155, or elements of the elevator hoistway 145 such as lighting.
  • the auxiliary electrical power supply may comprise a battery or battery bank or, e.g., an internal combustion engine.
  • the elevator 1000 may comprise a back-up energy supply system or an auxiliary energy storage system such as an internal combustion engine, a fuel cell, a flywheel, or a lead, nickel-cadmium, nickel-metal hybrid, lithium ion, or lithium polymer battery delivering a voltage of 12 V, 24 V or 48 V, or at least a connection to such as a system or systems if not part of the elevator 1000.
  • the back-up energy supply system or the auxiliary energy storage system may be used to operate the elevator 1000 such as by energizing the elevator control unit 1 100.
  • FIG. 2 shows at 200 a flow diagram of a method in accordance with an embodiment of the present invention.
  • Step 210 refers to a start-up phase of the method. Suitable equipment and components are obtained and systems assembled and configured for operation. Step 220 refers to charging the electrical energy storage 1 14 by through an electrical connection 120 of the elevator brake arrangement 1 10.
  • the charging at 220 may be performed by drawing electrical energy from the main electrical power supply or from the electric motor 155 decelerating and producing regenerative power.
  • Regenerative power refers herein to electrical power which may be produced by controlling the torque of the electric motor 155 appropriately, e.g. by an electrical drive 105, thus converting kinetic energy of the elevator car 130 into electrical power.
  • the charging may be performed by utilizing both electrical energy from the main electrical power supply 125 and the regenerative power from the electric motor 155, simultaneously or sequentially.
  • Step 230 refers to deactivating the elevator brake 1 16 by electrical power from the electrical energy storage 1 14.
  • the deactivating at 230 may additionally be performed by electrical energy from the main electrical power supply 125 of the elevator 1000 and the regenerative power from the electric motor simultaneously or sequentially.
  • Deactivating refers herein to changing the state of the elevator brake from activated to deactivated and/or to keep or maintain the elevator brake in the deactivated state.
  • the latter may occur, for example, when the brake has been deactivated and kept deactivated by electrical power from the main power supply and, subsequently, the source of power for deactivation the brake is being changed so as to draw power from the electrical energy storage 1 14 to maintain the brake in deactivated stated without activating the brake when changing the source of power.
  • the charging 220 and the deactivating 230 may be performed simultaneously or sequentially.
  • Method execution is stopped at step 240. Operating the elevator 1000 or the elevator brake 1 16 utilizing stored energy in the electrical energy storage 1 14 comprised in the elevator brake arrangement 1 10 is no longer needed.
  • electrical energy from the electrical energy storage 1 14 may be used to maintain the elevator brake 1 16 deactivated while driving the electric motor 155 by electrical energy from the main electrical power supply connection 100 of the elevator 1000.
  • This is advantageous because during operating the electric motor 155 to move the elevator car 130, the electrical power required to maintain the brake 1 16 deactivated is not simultaneously drawn from the main electrical power supply, thus, decreasing the input power of the elevator, for example, to utilize the capacity, for example limited by a fuse or protection device, of the main electrical power supply connection better, which may be particularly beneficial, for example, in case of a single-phase connection to the main electrical power supply 125.
  • the method according to an embodiment illustrated in Fig. 2 may be performed by the elevator control unit 1 100.
  • the method may be implemented at least partially with the electrical drive 105 or by an auxiliary controlling unit comprised in the elevator 1000.
  • the method may be performed once, intermittently or continuously (as depicted by the arrow 235 in Fig. 2), depending on or relative to, for example, an operating state of the elevator 1000.
  • Some operating states or modes of the elevator 1000 may relate to situations as described by way of example, and not by way of limitation, below.
  • the operating states or modes of the elevator 1000 described below may occur either during normal operating conditions or in emergency conditions.
  • First operating state or mode is such that the elevator car 130 is accelerating/decelerating and the elevator brake 1 16 is deactivated.
  • the accelerating/decelerating which may depend on the balance/unbalance between the elevator car 130 and the counter-weight 135, if any, may mean either consuming electrical power by the electric motor 155 or that the electric motor 155 is producing regenerative power. Whether the electric motor 155 is consuming or producing may depend on the loading condition of the elevator car 130 with respect to the mass of the counter-weight 135.
  • the accelerating/decelerating means that the electric motor 155 is consuming electrical power.
  • Second operating state or mode is such that the elevator car 130 is accelerating/decelerating and the elevator brake 1 16 is deactivated.
  • the accelerating/decelerating means that the electric motor 155 is producing regenerative power.
  • Third operating state or mode is such that the elevator car 130 is moving at about a constant speed and consuming electrical power which is typically less than in the first operating state or mode of the elevator 1000, and the elevator brake 1 16 is being deactivated.
  • Fourth operating state or mode is such that the elevator car 130 is moving at about a constant speed and produces regenerative electrical power which is typically less than in the second operating state or mode of the elevator 1000, and the elevator brake 1 16 is being deactivated.
  • Fifth operating state or mode is such that the elevator car is stopped and the elevator brake 1 16 is activated.
  • the elevator brake 1 16 in case of a typical electromechanical brake, does not consume electrical power for braking.
  • the operating state or mode of the elevator 1000 may be determined, for example, based on at least one of various parameters such as determined input power of the elevator 1000 or electrical drive 105, current or voltage determined by the electrical drive 105, load of the elevator car 130, position in the hoistway 145, acceleration/deceleration and speed of the elevator car 130, etc.
  • the operating state or mode of the elevator 1000 may be determined, for example, based on the electrical input power of the elevator 1000.
  • the electrical input power of the elevator 1000 may be determined by measurement of the input current of the elevator 1000 or current of the intermediate circuit of the electrical drive.
  • the determination of the electrical input power of the elevator 1000 may also utilize measurement of the input voltage of the elevator 1000 or the DC voltage of the intermediate circuit.
  • the determination of the operating state or mode may also include other parameters described hereinabove such as the load, speed and acceleration of the elevator car or the electric motor for moving the car.
  • the operating state or mode may be determined without regard to the electrical power, i.e., based on, for example, the load, speed, position and/or acceleration/deceleration of the elevator car 130.
  • the electrical energy storage 1 14 may be charged relative to or depending on the operating state or mode of the elevator 1000.
  • the electrical energy storage 1 14 may be charged at least in the first operating state or mode of the elevator 1000, if the electrical input power of the elevator 1000 is lower than a first threshold.
  • the first threshold may be selected, e.g., to be less than 25, 50 75, or 90 percent of the maximum electrical input power of the elevator 1000.
  • the first threshold depends on the power level required by the elevator brake 1 16.
  • Various embodiments of the present invention are particularly advantageous in connection with small power elevators having duty cycle (ED) approximately 40 percent or less than 40 percent, for example, 30 percent or 20 percent.
  • ED duty cycle
  • the electrical energy storage 1 14 may be charged at least in the second operating state or mode of the elevator 1000.
  • the electrical energy for charging may be drawn from the main electrical power supply 125 or from the electric motor 155 producing regenerative power.
  • the electrical energy storage 1 14 may be charged at least in one or both of the fourth and the fifth operating states or modes of the elevator 1000.
  • the elevator brake 1 16 may be deactivated by utilizing electrical energy from the electrical energy storage 1 14 relative to or depending on the operating state or mode of the elevator 1000.
  • the elevator brake 1 16 may be deactivated by utilizing electrical energy from the electrical energy storage 1 14 at least in the first operating state or mode of the elevator 1000.
  • the elevator brake 1 16 may be deactivated at least in the first operating state or mode of the elevator 1000 by utilizing electrical energy from the electrical energy storage 1 14, if the electrical input power of the elevator 1000 is higher than a predetermined electrical input power threshold, thus, avoiding drawing electrical power for braking from the main electrical power supply during the first operating state or mode.
  • the elevator brake 1 16 may be deactivated by utilizing electrical energy from the electrical energy storage 1 14 at least in one or several of the second, third and fourth operating states or modes of the elevator 1000.
  • the elevator brake 1 16 may be deactivated, thus consuming electrical power from the electrical energy storage 1 14, and the elevator car 130 is accelerating.
  • the charging of the electrical energy storage 1 14 may thus be avoided during the times when the elevator car 130 is being accelerated, or at least during the peak power time, in order to reduce the electrical input power of the elevator 1000.
  • the charging may be avoided during the times when the electrical input power of the elevator 1000 exceeds a predetermined electrical input power threshold so that protection devices, such as fuses, do not operate.
  • the predetermined electrical input power threshold may be, e.g., a maximum current that may be drawn from the main electrical power supply 125.
  • the charging of the electrical energy storage 1 14 may take place. This may be, for example, when the loading condition of the elevator car 130 is such that low level of electrical power is required to move the elevator car 130 at a constant speed.
  • the elevator brake 1 16 may always, when the electrical energy storage 1 14 has sufficient amount of electrical energy stored on it, deactivated by electrical power from the electrical energy storage 1 14. According to another embodiment of the present invention, the elevator brake 1 16 may be deactivated by electrical power from the electrical energy storage 1 14 only when the electrical input power of the elevator 1000 is higher than a predetermined electrical input power threshold thus reducing the amount of charging/discharging cycles of the electrical energy storage 1 14.
  • Figures 3A and 3B illustrate two examples of the electrical drive 105 in accordance with embodiments of the present invention.
  • the electrical drive 105 may be a frequency converter 31 which input may be connected to the main electrical power supply 125, in this case a single-phase, a two-phase or a three-phase electrical grid, and its output to the electric motor 155 of the elevator 1000.
  • the optional phase is shown with dashed line in Figs. 3A, 4A, 5 and 6.
  • the frequency converter 31 is capable of converting, for example, a voltage or a current having a first frequency to a voltage with a second frequency which is the same or different with respect to the first frequency.
  • the frequency converter 31 may comprise a rectifier with a switch and capable of operating in one or more quadrants.
  • the rectifier may be capable of converting the alternating current (AC) voltages and currents of the main electrical power supply into DC currents and DC voltages.
  • the frequency converter 31 may also comprise an inverter 32 capable of converting the DC voltages or currents into AC voltages or currents, thus controlling the operation of the electric motor 155, and capable of operating in one or more quadrants.
  • There may also be an intermediate circuit connected between the rectifier and the inverter 32.
  • the intermediate circuit may comprise an electrical storage element such as a capacitor or an inductor for smoothing a DC voltage or current.
  • FIGS 4A and 4B illustrate schematically embodiments of the elevator brake arrangement 1 10 in accordance with embodiments of the present invention.
  • Fig. 4A illustrates an embodiment utilizing an electrical drive 105 and in which the electrical power for the elevator brake arrangement 1 10, i.e. the electrical connection 120 of the elevator brake arrangement 1 10, may be drawn directly from the main electrical power supply 125.
  • the elevator brake arrangement 1 10 may comprise an electrical converter for converting the voltages and currents of the main electrical power supply to be suitable for the components of the elevator brake arrangement 1 10.
  • Figure 4B illustrates an electrical drive 105, either an intermediate circuit of a frequency converter 31 or an input circuit of an inverter 32.
  • the intermediate circuit or the input circuit may or may not comprise an energy storage element for smoothing voltage or current.
  • the electrical connection 120 of the elevator brake arrangement 1 10 is connected to the intermediate circuit or the input circuit of the electrical drive 105.
  • the elevator brake arrangement 1 10 comprises an electrical converter 1 12 capable of stepping down the voltage of the intermediate circuit or the input circuit to a level suitable for the electrical energy storage 1 14 of the elevator brake arrangement 1 10.
  • the voltage level may be, for example, 24 V or 48 V.
  • the elevator brake arrangement 1 10 comprises another electrical converter 1 12 capable of stepping up the voltage of the electrical energy storage of the elevator brake arrangement 1 10 to a level suitable for the elevator brake 1 16.
  • the elevator control unit 1 100 may monitor the condition and/or state-of-charge of the electrical energy storage 1 14 of the elevator brake arrangement 1 10.
  • the elevator brake arrangement 1 10 may comprise a functionality to monitor and prevent the state-of-charge of the electrical energy storage 1 14 to become too low.
  • the elevator brake arrangement 1 10 may also be configured to prevent the electrical converters 1 12 of the elevator brake arrangement 1 10 to cause short-circuit for the electrical energy storage 1 14.
  • Figure 5 illustrates an elevator brake arrangement 1 10 according to an embodiment of the present invention having the electrical energy storage 1 14 connected between two electrical converters 1 12A, 1 12B.
  • One of the electrical converters 1 12A, 1 12B may be a voltage step-down converter 1 12A for reducing a DC input voltage or the voltage of the intermediate circuit 600 to appropriate level for the electrical energy storage 1 14.
  • the electrical converter 1 12A may also be capable of convert AC into DC.
  • the other electrical converter 1 12B may be a voltage step-up converter 1 12B for increasing the voltage of the electrical energy storage 1 14 to appropriate level for the elevator brake 1 16.
  • the electrical converter 1 12 may comprise both the voltage step-down 1 12A and the voltage step-up converter 1 12B.
  • FIG. 6 illustrates schematically an elevator brake arrangement 1 10 according to an embodiment of the present invention.
  • the elevator brake 1 16 may be operated by electrical energy from the electrical energy storage 1 14.
  • the elevator brake 1 16 may be operated with electrical energy from the main electrical power supply 125.
  • the elevator brake arrangement 1 10 may comprise a brake controlling unit that may be configured to choose whether the elevator brake 1 16 may be operated by electrical energy from the electrical energy storage 1 14 or from the main electrical power supply 125.
  • the elevator brake arrangement 1 10 may comprise a switching device 61 .
  • the switching device 61 may be controlled by the elevator control unit 1 100 or by the brake control unit to decide wherefrom the electrical energy is being drawn.
  • the switching device 61 may comprise, for example, a switch or set of switches for choosing where the electrical power is drawn and/or a rectifier for converting the AC voltages and currents drawn from the main electrical power supply into suitable DC values for the elevator brake arrangement 1 10.
  • the elevator brake 1 16 may be operated by electrical energy from the main electrical power supply in case the electrical energy storage 1 14 is unavailable due to a failure or breakdown, or has too low a state-of-charge, such as lower than a predetermined state-of-charge threshold.
  • the predetermined state-of-charge threshold may be 10, 20, 30, 40 or 50%.
  • FIG. 7 illustrates schematically an elevator control unit 1 100 according to an embodiment of the present invention.
  • External units 701 may be connected to a communication interface 708 of the elevator control unit 1 100.
  • External unit 701 may comprise wireless connection or a connection by a wired manner.
  • the communication interface 708 provides interface for communication with external units 701 such as the elevator car 130, the electric motor 155, the doors of the landing floors 160, or the electrical drive 105 to the elevator control unit 1 100.
  • the elevator control unit 1 100 may comprise one or more processors 704, one or more memories 706 being volatile or non-volatile for storing portions of computer program code 707A-707N and any data values and possibly one or more user interface units 710.
  • the mentioned elements may be communicatively coupled to each other with e.g. an internal bus.
  • the processor 704 of the elevator control unit 1 100 is at least configured to implement at least some method steps as described.
  • the implementation of the method may be achieved by arranging the processor 704 to execute at least some portion of computer program code 707A-707N stored in the memory 706 causing the processor 704, and thus the elevator control unit 1 100, to implement one or more method steps as described.
  • the processor 704 is thus arranged to access the memory 706 and retrieve and store any information therefrom and thereto.
  • the processor 704 herein refers to any unit suitable for processing information and control the operation of the elevator control unit 1 100, among other tasks.
  • the operations may also be implemented with a microcontroller solution with embedded software.
  • the memory 706 is not limited to a certain type of memory only, but any memory type suitable for storing the described pieces of information may be applied in the context of the present invention.

Abstract

A method for controlling electrical input power of an elevator (1000) relative to an operating state of the elevator (1000), wherein the elevator (1000) comprises an elevator brake arrangement (110) comprising an elevator brake (116) and an electrical energy storage (114) electrically coupled to the elevator brake (116), the method comprising charging (220) the electrical energy storage (114) through an electrical connection (120) of the elevator brake arrangement (110), and deactivating (230) the elevator brake (116) by electrical energy from the electrical energy storage (114).

Description

METHOD FOR CONTROLLING ELECTRICAL INPUT POWER OF ELEVATOR, ELEVATOR CONTROL UNIT, COMPUTER PROGRAM PRODUCT, AND ELEVATOR UTILIZING THE METHOD THEREOF
TECHNICAL FIELD The invention concerns in general the technical field of elevators. The invention concerns especially methods for controlling the electrical input power of an elevator.
BACKGROUND
Electrical power required for operating an elevator is typically drawn from an electrical power grid through an electrical supply connection of the elevator. The elevator draws power at all times to match the required amount of power for operating the elevator car and energizing all components and sub-systems of the elevator. These components and sub-systems typically include an electric motor, lighting equipment, safety equipment, an electrical drive, an elevator brake, etc.
Typical elevators utilize electro-mechanical brakes, which are operated so that electrical power is required to energize an electromagnet which then deactivates the brake by applying a force via magnetic field. The deactivation of the brake consumes electrical energy. This typically happens when the elevator car of the elevator is moving or when the elevator car is about to be moved. Less or no power is consumed when the electro-mechanical brake is activated which happens so that, for example, a spring element pushes the brake into the activated state thus producing significant friction to decelerate, to stop or to keep the elevator car in its position. The drawback of the prior art solutions is that the power drawn from the electrical power grid may become too high, such as with respect to the properties or specifications of the point of coupling of the elevator to the grid or due other technical or economic reasons, when the elevator is accelerating or moving at a constant speed, and when at the same time the brake is in the deactivated state requiring significant level of electrical power. There is thus a need to control the electrical input power of the elevator, especially, relative to the operating state or mode of the elevator. SUMMARY
An objective of the present invention is to provide a method, an elevator control unit, a computer program product, and an elevator for controlling electrical input power of the elevator relative to the operating state of the elevator. Another objective of the present invention is that the method, the elevator control unit, the computer program product, and the elevator reduce the input power of the elevator at least in some conditions in which the reduction is needed.
The objectives of the invention are reached by a method, an elevator control unit and a computer program product as defined by the respective independent claims.
According to a first aspect, a method for controlling electrical input power of an elevator relative to an operating state of the elevator is provided. The elevator comprises an elevator brake arrangement comprising an elevator brake and an electrical energy storage electrically coupled to the elevator brake. The method comprises
- charging the electrical energy storage through an electrical connection of the elevator brake arrangement, and
- deactivating the elevator brake by electrical energy from the electrical energy storage.
The method may comprise keeping or maintaining the elevator brake deactivated by electrical energy from the electrical energy storage while simultaneously driving electric motor by electrical energy from the main electrical power supply connection of the elevator. The method may comprise determining the operating state of the elevator based on at least electrical input power of the elevator. Alternatively or in addition, one or several other parameters may be taken into account such as position, speed, acceleration/deceleration or rate of acceleration/deceleration of the elevator car or the electric motor of the elevator for determining the operating state.
The charging may comprise charging the electrical energy storage by electrical power drawn from a main electrical power supply connection of the elevator. The charging may comprise charging the electrical energy storage by electrical power generated by an electric motor of the elevator when the electric motor is being electrically decelerated, i.e., by regenerative electrical energy.
The charging may comprise charging the electrical energy storage through an intermediate circuit of an electrical drive or an input circuit of an inverter operating the electric motor of the elevator.
The deactivating may comprise deactivating the elevator brake by electrical power drawn from a main electrical power supply connection of the elevator, if a state-of-charge value of the electrical energy storage is lower than a predetermined state-of-charge threshold.
The deactivating may comprise deactivating the elevator brake by electrical power drawn from the electrical energy storage, if an electrical input power of an elevator is higher than a predetermined electrical input power threshold.
According to a second aspect, an elevator control unit for controlling electrical input power of an elevator is provided. The elevator comprises an elevator brake arrangement, wherein the elevator brake arrangement comprises an elevator brake and an electrical energy storage electrically coupled to the elevator brake. The elevator control unit comprises at least one processor, and at least one memory storing at least one portion of computer program code. The at least one processor being configured to cause the elevator control unit at least to perform:
- charge the electrical energy storage through an electrical connection of the elevator brake arrangement, and
- deactivate the elevator brake by electrical energy from the electrical energy storage.
According to a third aspect, a computer program product comprising program instructions is provided. Said instructions, when executed by an elevator control unit, cause the elevator control unit to perform the method according to the first aspect. According to a fourth aspect, an elevator for controlling electrical input power of the elevator is provided. The elevator brake arrangement comprises an elevator brake and an electrical energy storage electrically coupled to the elevator brake. The elevator further comprises an elevator control unit configured to at least charge the electrical energy storage through an electrical connection of the elevator brake arrangement, and deactivate the elevator brake by electrical energy from the electrical energy storage. The elevator control unit and the elevator brake arrangement are communicatively coupled to each other.
The present invention provides a method for controlling electrical input power of an elevator utilizing an electrical energy storage for deactivating the elevator brake. The method provides advantages over known solutions such that the electrical input power of the elevator may be reduced by charging the electrical energy storage of the elevator brake arrangement when the elevator power demand is low or by utilizing regenerative power from the electric motor of the elevator, and then utilizing stored electrical energy in the electrical energy storage to deactivate the elevator brake, thus avoiding drawing the power from the electrical supply grid.
Various other advantages will become clear to a skilled person based on the following detailed description.
The expression "a plurality of" refers herein to any positive integer starting from two, e.g. to two, three, or four. The terms "first", "second", "third", "fourth" and "fifth" do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.
The exemplary embodiments of the present invention presented herein are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used herein as an open limitation that does not exclude the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated.
The novel features which are considered as characteristic of the present invention are set forth in particular in the appended claims. The present invention itself, however, both as to its construction and its method of operation, together with additional objectives and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF FIGURES
The embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.
Figure 1 illustrates schematically an elevator according to an embodiment of the present invention.
Figure 2 illustrates a flow diagram presenting an embodiment of a method in accordance with the present invention. Figures 3A and 3B illustrate examples of the electrical drive in accordance with embodiments of the present invention.
Figures 4A and 4B illustrate schematically embodiments of an elevator brake arrangement in accordance with embodiments of the present invention.
Figure 5 illustrates an elevator brake arrangement according to an embodiment of the present invention.
Figure 6 illustrates an elevator brake arrangement according to an embodiment of the present invention.
Figure 7 illustrates schematically an elevator control unit according to an embodiment of the present invention. DESCRIPTION OF SOME EMBODIMENTS
Figure 1 illustrates schematically an elevator 1000 according to an embodiment of the present invention. The elevator 1000 may comprise an electric motor 155 for moving an elevator car 130 comprised in the elevator 1000. The elevator car 130 may be mechanically coupled to the electric motor 155, for example, by a hoisting rope 140, hydraulic means or in more direct manner in case of a linear motor. The operation of the electric motor 155 may be controlled by an electrical drive 105 such as a frequency converter or an inverter. The hoisting rope 140 may comprise, for example, steel or carbon fibers. The term 'hoisting rope' does not limit the form of the element anyhow. For example, the hoisting rope 140 may be implemented as a rope, a belt, or a track in ropeless or rope-free elevators. The elevator 1000 may comprise an elevator control unit 1 100 for controlling the operation of the elevator 1000. The elevator control unit 1 100 may be a separate device or may be comprised in the other components of the elevator 1000 such as in or as a part of the electrical drive 105. The elevator control unit 1 100 may also be implemented in a distributed manner so that, e.g., one portion of the elevator control unit 1 100 may be comprised in the electrical drive 105 and another portion in the elevator car 130. The elevator control unit 1 100 may also be arranged in distributed manner at more than two locations or in more than two devices.
The elevator 1000 may comprise an elevator brake arrangement 1 10 comprising an elevator brake 1 16, preferably, an electromechanical elevator brake 1 16. The elevator brake arrangement 1 10 may be connected to an intermediate circuit of a frequency converter, an input circuit of an inverter or directly to the main electrical power supply connection 100 of the elevator 1000. In the last case, the elevator brake arrangement 1 10 may comprise an electrical converter 1 12 for converting voltage and/or current to suitable levels to operate the elevator brake arrangement 1 10. There may also be such an electrical converter 1 12 if the elevator brake arrangement 1 10 is connected to the intermediate circuit or the input circuit of the electrical drive 105.
The elevator 1000 may comprise, for example, as a part of the brake arrangement 1 10, a brake controlling unit for controlling the operation of the elevator brake 1 16, such as, to deactivate and/or activate the elevator brake 1 16. The brake(s) 1 16 may operate such as the magnetization of the coils of the brake(s) 1 16 deactivates the brake(s) 1 16 by force applied via magnetic field. The brake controlling unit may be integrated into the brake 1 16 or may be a separate brake controller device.
The electrical energy storage 1 14 may be used in normal operating conditions and/or in emergency conditions of the elevator 1000. The normal operating conditions refer to conditions in which the elevator 1000 serves its landing floors in normal manner. The emergency conditions refer to conditions in which there is, for example, a failure or loss of the main electrical power supply 125. The emergency conditions may refer also to conditions in which the safety circuit of the elevator 1000 has been interrupted thus indicating conditions apart from the normal operating conditions. The elevator brake arrangement 1 10 may comprise an electrical energy storage 1 14. The electrical energy storage 1 14 may be connected to the intermediate circuit or the input circuit of the electrical drive 105, preferably, via the electrical converter 1 12 such as a voltage step-down converter. The elevator brake arrangement 1 10 may also comprise a brake control unit or a part of the elevator control unit 1 100.
Other elements shown in Fig. 1 , which may or may not be utilized in embodiments of the present invention, are a main electrical power supply 125 such as a three- or single-phase electrical power grid, an electrical connection 120 of the elevator brake arrangement 1 10, connection means 165 between the electrical drive 105 and the electric motor 155. The elevator car 130 may operate in a hoistway 145 serving landing floors 160. There may or may not be a counter-weight 135 utilized in an embodiment of the present invention.
According to an embodiment of the present invention, the electric motor 155 may be a single-phase, two-phase or three-phase electric motor 155. The electric motor 155 may be a permanent magnet motor such as a surface- mounted or an interior permanent magnet motor. The electric motor 155 may be a linear, radial, axial, or transverse type of a motor. A rotor of the permanent magnet motor has at least one permanent magnet providing magnetization of the rotor, i.e. excitation. In some embodiments, the electric motor 155 may be a synchronous motor comprising a magnetizing circuit or an exciter in connection with the rotor. According to another embodiment, the electric motor 155 may be an asynchronous electric motor such as an induction motor, or a doubly-fed induction motor or an asynchronous slip ring motor capable of being excited externally via the slip ring, for example, via brushes or wirelessly such as by induction. The excitation may be provided by, for example, a permanent magnet or a battery-operated exciter. The excitation may be based on injecting direct current (DC) into a magnetization circuit of the rotor, thus magnetizing the rotor. In various embodiments, the exciter may be at least partly coupled to the rotor. According to an embodiment of the present invention, the elevator 1000 may have an auxiliary electrical power supply. The auxiliary electrical power supply may be utilized, for example, in situations in which there is a failure of a main electrical power supply of the elevator 1000, such as failure in an electrical power grid having, for example, a fundamental frequency of 50 or 60 Hz, the elevator 1000. According to an embodiment of the present invention, the auxiliary electrical power supply may be an electrical supply grid other than the main electrical power supply or an electrical power source such as a gas turbine engine, an internal combustion engine or a fuel cell. The auxiliary electrical power supply may be used to feed power to operate the electrical drive 105 as well as other components required to be operable during conditions without power available from the main electrical power supply. The other components required to be operable may be, for example, part of the elevator controlling system, components of the elevator car 130, the magnetizing circuit or the exciter of the electric motor 155, or elements of the elevator hoistway 145 such as lighting. The auxiliary electrical power supply may comprise a battery or battery bank or, e.g., an internal combustion engine.
According to an embodiment of the present invention, the elevator 1000 may comprise a back-up energy supply system or an auxiliary energy storage system such as an internal combustion engine, a fuel cell, a flywheel, or a lead, nickel-cadmium, nickel-metal hybrid, lithium ion, or lithium polymer battery delivering a voltage of 12 V, 24 V or 48 V, or at least a connection to such as a system or systems if not part of the elevator 1000. The back-up energy supply system or the auxiliary energy storage system may be used to operate the elevator 1000 such as by energizing the elevator control unit 1 100. If the back-up energy supply system or the auxiliary energy storage system is insufficient for operating the electric motor 155 to drive the elevator car 130, the operator may manually operate, such as deactivate, an elevator brake arrangement in order to cause the movement of the elevator car 130. Figure 2 shows at 200 a flow diagram of a method in accordance with an embodiment of the present invention.
Step 210 refers to a start-up phase of the method. Suitable equipment and components are obtained and systems assembled and configured for operation. Step 220 refers to charging the electrical energy storage 1 14 by through an electrical connection 120 of the elevator brake arrangement 1 10.
According to an embodiment of the present invention, the charging at 220 may be performed by drawing electrical energy from the main electrical power supply or from the electric motor 155 decelerating and producing regenerative power. Regenerative power refers herein to electrical power which may be produced by controlling the torque of the electric motor 155 appropriately, e.g. by an electrical drive 105, thus converting kinetic energy of the elevator car 130 into electrical power. According to an embodiment, the charging may be performed by utilizing both electrical energy from the main electrical power supply 125 and the regenerative power from the electric motor 155, simultaneously or sequentially.
Step 230 refers to deactivating the elevator brake 1 16 by electrical power from the electrical energy storage 1 14. According to an embodiment of the present invention, the deactivating at 230 may additionally be performed by electrical energy from the main electrical power supply 125 of the elevator 1000 and the regenerative power from the electric motor simultaneously or sequentially. Deactivating refers herein to changing the state of the elevator brake from activated to deactivated and/or to keep or maintain the elevator brake in the deactivated state. The latter may occur, for example, when the brake has been deactivated and kept deactivated by electrical power from the main power supply and, subsequently, the source of power for deactivation the brake is being changed so as to draw power from the electrical energy storage 1 14 to maintain the brake in deactivated stated without activating the brake when changing the source of power.
According to an embodiment of the present invention, the charging 220 and the deactivating 230 may be performed simultaneously or sequentially.
Method execution is stopped at step 240. Operating the elevator 1000 or the elevator brake 1 16 utilizing stored energy in the electrical energy storage 1 14 comprised in the elevator brake arrangement 1 10 is no longer needed.
According to an embodiment of the present invention, electrical energy from the electrical energy storage 1 14 may be used to maintain the elevator brake 1 16 deactivated while driving the electric motor 155 by electrical energy from the main electrical power supply connection 100 of the elevator 1000. This is advantageous because during operating the electric motor 155 to move the elevator car 130, the electrical power required to maintain the brake 1 16 deactivated is not simultaneously drawn from the main electrical power supply, thus, decreasing the input power of the elevator, for example, to utilize the capacity, for example limited by a fuse or protection device, of the main electrical power supply connection better, which may be particularly beneficial, for example, in case of a single-phase connection to the main electrical power supply 125.
The method according to an embodiment illustrated in Fig. 2 may be performed by the elevator control unit 1 100. According to an embodiment of the present invention, the method may be implemented at least partially with the electrical drive 105 or by an auxiliary controlling unit comprised in the elevator 1000. Furthermore, the method may be performed once, intermittently or continuously (as depicted by the arrow 235 in Fig. 2), depending on or relative to, for example, an operating state of the elevator 1000.
Some operating states or modes of the elevator 1000 may relate to situations as described by way of example, and not by way of limitation, below. The operating states or modes of the elevator 1000 described below may occur either during normal operating conditions or in emergency conditions. First operating state or mode is such that the elevator car 130 is accelerating/decelerating and the elevator brake 1 16 is deactivated. The accelerating/decelerating, which may depend on the balance/unbalance between the elevator car 130 and the counter-weight 135, if any, may mean either consuming electrical power by the electric motor 155 or that the electric motor 155 is producing regenerative power. Whether the electric motor 155 is consuming or producing may depend on the loading condition of the elevator car 130 with respect to the mass of the counter-weight 135. In the first operating state or mode, particularly, the accelerating/decelerating means that the electric motor 155 is consuming electrical power. Second operating state or mode is such that the elevator car 130 is accelerating/decelerating and the elevator brake 1 16 is deactivated. In the second operating state or mode, the accelerating/decelerating means that the electric motor 155 is producing regenerative power. Third operating state or mode is such that the elevator car 130 is moving at about a constant speed and consuming electrical power which is typically less than in the first operating state or mode of the elevator 1000, and the elevator brake 1 16 is being deactivated. Fourth operating state or mode is such that the elevator car 130 is moving at about a constant speed and produces regenerative electrical power which is typically less than in the second operating state or mode of the elevator 1000, and the elevator brake 1 16 is being deactivated.
Fifth operating state or mode is such that the elevator car is stopped and the elevator brake 1 16 is activated. In the fifth operating state or mode, the elevator brake 1 16, in case of a typical electromechanical brake, does not consume electrical power for braking.
The operating state or mode of the elevator 1000 may be determined, for example, based on at least one of various parameters such as determined input power of the elevator 1000 or electrical drive 105, current or voltage determined by the electrical drive 105, load of the elevator car 130, position in the hoistway 145, acceleration/deceleration and speed of the elevator car 130, etc.
According to an embodiment of the present invention, the operating state or mode of the elevator 1000 may be determined, for example, based on the electrical input power of the elevator 1000. The electrical input power of the elevator 1000 may be determined by measurement of the input current of the elevator 1000 or current of the intermediate circuit of the electrical drive. The determination of the electrical input power of the elevator 1000 may also utilize measurement of the input voltage of the elevator 1000 or the DC voltage of the intermediate circuit. In addition to the input power, the determination of the operating state or mode may also include other parameters described hereinabove such as the load, speed and acceleration of the elevator car or the electric motor for moving the car. According to some embodiment of the present invention, the operating state or mode may be determined without regard to the electrical power, i.e., based on, for example, the load, speed, position and/or acceleration/deceleration of the elevator car 130. According to various embodiments of the present invention, the electrical energy storage 1 14 may be charged relative to or depending on the operating state or mode of the elevator 1000.
According to an embodiment of the present invention, the electrical energy storage 1 14 may be charged at least in the first operating state or mode of the elevator 1000, if the electrical input power of the elevator 1000 is lower than a first threshold. The first threshold may be selected, e.g., to be less than 25, 50 75, or 90 percent of the maximum electrical input power of the elevator 1000. According to an embodiment of the present invention, the first threshold depends on the power level required by the elevator brake 1 16.
Various embodiments of the present invention are particularly advantageous in connection with small power elevators having duty cycle (ED) approximately 40 percent or less than 40 percent, for example, 30 percent or 20 percent. This means that elevator 1000 is on average standing idle long enough to enable charging during standing idle, i.e., the idle state, for example, during the fifth operating state or mode.
According to an embodiment of the present invention, the electrical energy storage 1 14 may be charged at least in the second operating state or mode of the elevator 1000. The electrical energy for charging may be drawn from the main electrical power supply 125 or from the electric motor 155 producing regenerative power.
According to an embodiment of the present invention, the electrical energy storage 1 14 may be charged at least in one or both of the fourth and the fifth operating states or modes of the elevator 1000. According to various embodiments of the present invention, the elevator brake 1 16 may be deactivated by utilizing electrical energy from the electrical energy storage 1 14 relative to or depending on the operating state or mode of the elevator 1000.
According to an embodiment of the present invention, the elevator brake 1 16 may be deactivated by utilizing electrical energy from the electrical energy storage 1 14 at least in the first operating state or mode of the elevator 1000. The elevator brake 1 16 may be deactivated at least in the first operating state or mode of the elevator 1000 by utilizing electrical energy from the electrical energy storage 1 14, if the electrical input power of the elevator 1000 is higher than a predetermined electrical input power threshold, thus, avoiding drawing electrical power for braking from the main electrical power supply during the first operating state or mode. According to an embodiment of the present invention, the elevator brake 1 16 may be deactivated by utilizing electrical energy from the electrical energy storage 1 14 at least in one or several of the second, third and fourth operating states or modes of the elevator 1000.
According to an embodiment of the present invention, the elevator brake 1 16 may be deactivated, thus consuming electrical power from the electrical energy storage 1 14, and the elevator car 130 is accelerating. The charging of the electrical energy storage 1 14 may thus be avoided during the times when the elevator car 130 is being accelerated, or at least during the peak power time, in order to reduce the electrical input power of the elevator 1000. According to an embodiment of the present invention, the charging may be avoided during the times when the electrical input power of the elevator 1000 exceeds a predetermined electrical input power threshold so that protection devices, such as fuses, do not operate. The predetermined electrical input power threshold may be, e.g., a maximum current that may be drawn from the main electrical power supply 125.
According to an embodiment of the present invention, during times when the electrical input power of the elevator 1000 is less than the predetermined threshold value, the charging of the electrical energy storage 1 14 may take place. This may be, for example, when the loading condition of the elevator car 130 is such that low level of electrical power is required to move the elevator car 130 at a constant speed.
According to another embodiment of the present invention, the elevator brake 1 16 may always, when the electrical energy storage 1 14 has sufficient amount of electrical energy stored on it, deactivated by electrical power from the electrical energy storage 1 14. According to another embodiment of the present invention, the elevator brake 1 16 may be deactivated by electrical power from the electrical energy storage 1 14 only when the electrical input power of the elevator 1000 is higher than a predetermined electrical input power threshold thus reducing the amount of charging/discharging cycles of the electrical energy storage 1 14.
Figures 3A and 3B illustrate two examples of the electrical drive 105 in accordance with embodiments of the present invention. In Fig. 3A, the electrical drive 105 may be a frequency converter 31 which input may be connected to the main electrical power supply 125, in this case a single-phase, a two-phase or a three-phase electrical grid, and its output to the electric motor 155 of the elevator 1000. The optional phase is shown with dashed line in Figs. 3A, 4A, 5 and 6. The frequency converter 31 is capable of converting, for example, a voltage or a current having a first frequency to a voltage with a second frequency which is the same or different with respect to the first frequency. The frequency converter 31 may comprise a rectifier with a switch and capable of operating in one or more quadrants. The rectifier may be capable of converting the alternating current (AC) voltages and currents of the main electrical power supply into DC currents and DC voltages. The frequency converter 31 may also comprise an inverter 32 capable of converting the DC voltages or currents into AC voltages or currents, thus controlling the operation of the electric motor 155, and capable of operating in one or more quadrants. There may also be an intermediate circuit connected between the rectifier and the inverter 32. The intermediate circuit may comprise an electrical storage element such as a capacitor or an inductor for smoothing a DC voltage or current.
Figures 4A and 4B illustrate schematically embodiments of the elevator brake arrangement 1 10 in accordance with embodiments of the present invention. Fig. 4A illustrates an embodiment utilizing an electrical drive 105 and in which the electrical power for the elevator brake arrangement 1 10, i.e. the electrical connection 120 of the elevator brake arrangement 1 10, may be drawn directly from the main electrical power supply 125. In this case, the elevator brake arrangement 1 10 may comprise an electrical converter for converting the voltages and currents of the main electrical power supply to be suitable for the components of the elevator brake arrangement 1 10.
Figure 4B illustrates an electrical drive 105, either an intermediate circuit of a frequency converter 31 or an input circuit of an inverter 32. The intermediate circuit or the input circuit may or may not comprise an energy storage element for smoothing voltage or current. According to the embodiment in Fig. 4B, the electrical connection 120 of the elevator brake arrangement 1 10 is connected to the intermediate circuit or the input circuit of the electrical drive 105.
According to an embodiment of the present invention, the elevator brake arrangement 1 10 comprises an electrical converter 1 12 capable of stepping down the voltage of the intermediate circuit or the input circuit to a level suitable for the electrical energy storage 1 14 of the elevator brake arrangement 1 10. The voltage level may be, for example, 24 V or 48 V. According to another embodiment, the elevator brake arrangement 1 10 comprises another electrical converter 1 12 capable of stepping up the voltage of the electrical energy storage of the elevator brake arrangement 1 10 to a level suitable for the elevator brake 1 16.
According to an embodiment of the present invention, the elevator control unit 1 100 may monitor the condition and/or state-of-charge of the electrical energy storage 1 14 of the elevator brake arrangement 1 10. According to an embodiment of the present invention, the elevator brake arrangement 1 10 may comprise a functionality to monitor and prevent the state-of-charge of the electrical energy storage 1 14 to become too low. The elevator brake arrangement 1 10 may also be configured to prevent the electrical converters 1 12 of the elevator brake arrangement 1 10 to cause short-circuit for the electrical energy storage 1 14.
Figure 5 illustrates an elevator brake arrangement 1 10 according to an embodiment of the present invention having the electrical energy storage 1 14 connected between two electrical converters 1 12A, 1 12B. One of the electrical converters 1 12A, 1 12B may be a voltage step-down converter 1 12A for reducing a DC input voltage or the voltage of the intermediate circuit 600 to appropriate level for the electrical energy storage 1 14. The electrical converter 1 12A may also be capable of convert AC into DC. The other electrical converter 1 12B may be a voltage step-up converter 1 12B for increasing the voltage of the electrical energy storage 1 14 to appropriate level for the elevator brake 1 16. According to an embodiment of the present invention, the electrical converter 1 12 may comprise both the voltage step-down 1 12A and the voltage step-up converter 1 12B.
Figure 6 illustrates schematically an elevator brake arrangement 1 10 according to an embodiment of the present invention. As can be seen, the elevator brake 1 16 may be operated by electrical energy from the electrical energy storage 1 14. Alternatively or in addition, the elevator brake 1 16 may be operated with electrical energy from the main electrical power supply 125.
According to an embodiment of the present invention, the elevator brake arrangement 1 10 may comprise a brake controlling unit that may be configured to choose whether the elevator brake 1 16 may be operated by electrical energy from the electrical energy storage 1 14 or from the main electrical power supply 125. The elevator brake arrangement 1 10 may comprise a switching device 61 . The switching device 61 may be controlled by the elevator control unit 1 100 or by the brake control unit to decide wherefrom the electrical energy is being drawn. The switching device 61 may comprise, for example, a switch or set of switches for choosing where the electrical power is drawn and/or a rectifier for converting the AC voltages and currents drawn from the main electrical power supply into suitable DC values for the elevator brake arrangement 1 10.
According to an embodiment, the elevator brake 1 16 may be operated by electrical energy from the main electrical power supply in case the electrical energy storage 1 14 is unavailable due to a failure or breakdown, or has too low a state-of-charge, such as lower than a predetermined state-of-charge threshold. According to an embodiment of the present invention, the predetermined state-of-charge threshold may be 10, 20, 30, 40 or 50%.
Figure 7 illustrates schematically an elevator control unit 1 100 according to an embodiment of the present invention. External units 701 may be connected to a communication interface 708 of the elevator control unit 1 100. External unit 701 may comprise wireless connection or a connection by a wired manner. The communication interface 708 provides interface for communication with external units 701 such as the elevator car 130, the electric motor 155, the doors of the landing floors 160, or the electrical drive 105 to the elevator control unit 1 100. There may also be connecting to the external system, such as a laptop or a handheld device. There may also be a connection to a database of the elevator 1000 or an external database including information used in controlling the operation of the elevator 1 000.
The elevator control unit 1 100 may comprise one or more processors 704, one or more memories 706 being volatile or non-volatile for storing portions of computer program code 707A-707N and any data values and possibly one or more user interface units 710. The mentioned elements may be communicatively coupled to each other with e.g. an internal bus.
The processor 704 of the elevator control unit 1 100 is at least configured to implement at least some method steps as described. The implementation of the method may be achieved by arranging the processor 704 to execute at least some portion of computer program code 707A-707N stored in the memory 706 causing the processor 704, and thus the elevator control unit 1 100, to implement one or more method steps as described. The processor 704 is thus arranged to access the memory 706 and retrieve and store any information therefrom and thereto. For sake of clarity, the processor 704 herein refers to any unit suitable for processing information and control the operation of the elevator control unit 1 100, among other tasks. The operations may also be implemented with a microcontroller solution with embedded software. Similarly, the memory 706 is not limited to a certain type of memory only, but any memory type suitable for storing the described pieces of information may be applied in the context of the present invention.
The specific examples provided in the description given above should not be construed as limiting the applicability and/or the interpretation of the appended claims. Lists and groups of examples provided in the description given above are not exhaustive unless otherwise explicitly stated.

Claims

1 . A method for controlling electrical input power of an elevator (1000) relative to an operating state of the elevator (1000), wherein the elevator (1000) comprises an elevator brake arrangement (1 10) comprising an elevator brake (1 16) and an electrical energy storage (1 14) electrically coupled to the elevator brake (1 16), the method comprising
- charging (220) the electrical energy storage (1 14) through an electrical connection (120) of the elevator brake arrangement (1 10), and
- deactivating (230) the elevator brake (1 16) by electrical energy from the electrical energy storage (1 14).
2. The method according to claim 1 , comprising keeping the elevator brake (1 16) deactivated by electrical energy from the electrical energy storage (1 14) while simultaneously driving electric motor by electrical energy from the main electrical power supply connection (100) of the elevator (1000).
3. The method according to claim 1 or 2, comprising determining the operating state of the elevator (1000) based on at least said electrical input power of the elevator (1000).
4. The method according to any one of the preceding claims, wherein the charging (220) comprises charging the electrical energy storage (1 14) by electrical power drawn from a main electrical power supply connection (100) of the elevator (1000).
5. The method according to any one of the preceding claims, wherein the charging (220) comprises charging the electrical energy storage (1 14) by electrical power generated by an electric motor (155) of the elevator (1000) when the electric motor (155) is being electrically decelerated.
6. The method according to any one of the preceding claims, wherein the charging (220) comprises charging the electrical energy storage (1 14) through an intermediate circuit (600) of an electrical drive (105) or an input circuit of an inverter (32) operating the electric motor (155) of the elevator (1000).
7. The method according to any one of the preceding claims, wherein the deactivating (230) comprises deactivating the elevator brake (1 16) by electrical power drawn from a main electrical power supply connection (100) of the elevator (1000), if a state-of-charge value of the electrical energy storage (1 14) is lower than a predetermined state-of-charge threshold.
8. The method according to any one of the preceding claims, wherein the deactivating (230) comprises deactivating the elevator brake (1 16) by electrical power drawn from the electrical energy storage (1 14), if an electrical input power of an elevator (1000) is higher than a predetermined electrical input power threshold.
9. An elevator control unit (1 100) for controlling electrical input power of an elevator (1000) comprising an elevator brake arrangement (1 10), wherein the elevator brake arrangement (1 10) comprises an elevator brake (1 16) and an electrical energy storage (1 14) electrically coupled to the elevator brake (1 16), the elevator control unit (1 100) comprising:
- at least one processor (704), and - at least one memory (706) storing at least one portion of computer program code (707A-707N), wherein the at least one processor (704) being configured to cause the elevator control unit (1 100) at least to perform:
- charge (220) the electrical energy storage (1 14) through an electrical connection (120) of the elevator brake arrangement (1 10), and
- deactivate (230) the elevator brake (1 16) by electrical energy from the electrical energy storage (1 14).
10. A computer program product comprising program instructions which when executed by an elevator control unit (1 100) cause the elevator control unit (1 100) to perform the method according to any one of the preceding claims 1 -8.
1 1 . An elevator (1000) for controlling electrical input power of the elevator (1000), wherein the elevator brake arrangement (1 10) comprises an elevator brake (1 16) and an electrical energy storage (1 14) electrically coupled to the elevator brake (1 16), the elevator (1000) further comprising an elevator control unit (1 100) configured to at least: - charge (220) the electrical energy storage (1 14) through an electrical connection (120) of the elevator brake arrangement (1 10), and
- deactivate (230) the elevator brake (1 16) by electrical energy from the electrical energy storage (1 14), and wherein the elevator control unit (1 100) and the elevator brake arrangement (1 10) are communicatively coupled to each other.
PCT/FI2017/050036 2017-01-24 2017-01-24 Method for controlling electrical input power of elevator, elevator control unit, computer program product, and elevator utilizing the method thereof WO2018138403A1 (en)

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Publication number Priority date Publication date Assignee Title
US11840423B2 (en) 2018-12-14 2023-12-12 Otis Elevator Company Hybrid energy storage system architectures

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EP1067081A1 (en) * 1999-01-25 2001-01-10 Mitsubishi Denki Kabushiki Kaisha Elevator brake control device
US20010017237A1 (en) * 2000-02-28 2001-08-30 Shinji Tominaga Elevator control apparatus
WO2005040027A1 (en) * 2003-10-07 2005-05-06 Otis Elevator Company Electrical elevator rescue system
WO2011001197A1 (en) * 2009-07-02 2011-01-06 Otis Elevator Company Elevator rescue system
EP2289832A1 (en) * 2008-06-27 2011-03-02 Mitsubishi Electric Corporation Elevator apparatus and operating method thereof

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Publication number Priority date Publication date Assignee Title
EP1067081A1 (en) * 1999-01-25 2001-01-10 Mitsubishi Denki Kabushiki Kaisha Elevator brake control device
US20010017237A1 (en) * 2000-02-28 2001-08-30 Shinji Tominaga Elevator control apparatus
WO2005040027A1 (en) * 2003-10-07 2005-05-06 Otis Elevator Company Electrical elevator rescue system
EP2289832A1 (en) * 2008-06-27 2011-03-02 Mitsubishi Electric Corporation Elevator apparatus and operating method thereof
WO2011001197A1 (en) * 2009-07-02 2011-01-06 Otis Elevator Company Elevator rescue system

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* Cited by examiner, † Cited by third party
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US11840423B2 (en) 2018-12-14 2023-12-12 Otis Elevator Company Hybrid energy storage system architectures

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