Device and method for reducing the power of the supply connection in lift systems

• US 20030089557A1
• Filed: 09/24/2002
• Published: 05/15/2003
• Est. Priority Date: 03/31/2000
• Status: Active Grant

• Current Assignee: Inventio AG (Schindler Holding AG)
• Original Assignee: Inventio AG (Schindler Holding AG)
• Inventors: Eilinger, Thomas
• Granted Patent: US 6,742,630 B2
• Time in Patent Office: Days
• US Class Current: 187/296
• CPC Class Codes: B66B 1/30 effective on driving gear , e.g. acting on power electronics, on inverter or rectifier controlled motor
• CPC Class Codes: Y02B 50/00 Energy efficient technologies in elevators, escalators and moving walkways, e.g. energy saving or recuperation technologies

Abstract

Elevator installations with electric drive systems are equipped with devices (10) to reduce the power supply connection rating which have energy storage units (11) which are formed entirely or partly from so-called supercapacitors (13). The device (10) according to the invention has the effect on the one hand that power peaks during starting and braking operations are compensated by the exchange of energy between the storage unit (11) and motor supply, and on the other hand that the power consumption occurring during a trip is also spread over a part of the at-rest time. Supercapacitors (13) as energy stores tolerate by comparison with electrochemically acting accumulators a much higher number of charging and discharging cycles at high values of current.

Claims

1. Device to reduce the power supply connection rating of elevator installations with electric drive systems which has an energy storage unit (11) for electric energy characterized in that

the energy storage unit (11) contains capacitors in the form of supercapacitors (13).

2. Device according to claim 1, characterized in that the energy storage unit (11) contains as storage medium only supercapacitors (13).

3. Device according to claim 1, characterized in that the energy storage unit (11) contains as storage medium a combination of supercapacitors (13) with accumulators (14), i.e. with electrically-acting secondary elements.

4. Device according to claim 1, characterized in that the energy storage unit (11) consists of a combination of supercapacitors (13) with fuel cells.

5. Device according to one of claims 1 to 4, characterized in that

it operates in conjunction with one or more frequency converters (1) with each of which the rotational speed of an associated three-phase elevator motor (9) and thereby the traveling speed of the corresponding elevator is regulated.

6. Device according to one of claims 1 to 5, characterized in that

braking energy which occurs is fed into the energy storage unit (11) until its capacity is fully utilized and that if the need arises excess braking energy is converted into heat in the braking module (7) of the frequency converter (1).

7. Device according to one of claims 1 to 6, characterized in that

it is installed either in stationary fashion in the building or in mobile fashion on elevator vehicles with integral drives for travel.

8. Device according to one of claims 1 to 6, characterized in that

in a group of several elevators with frequency-controlled drives the DC links (5) of several motorside inverters are connected in parallel to a common DC link (16) and supplied with power from a single power supply module (15), and that a single energy storage unit according to the invention (11) is connected to the common voltage-controlled DC link (16).

9. Method to reduce the power supply connection rating of elevator installations with electric drive systems, characterized in that

electric energy is stored in an energy storage unit (11) which contains capacitors in the form of supercapacitors (13) and that before each elevator trip the energy required for the forthcoming trip is determined based on available information such as the load situation and trip destination, that a check is made whether the energy content momentarily present in the energy storage unit (11) together with the continuous supply from the power supply is sufficient for the trip, and that if necessary the start is delayed until the energy storage unit is sufficiently charged.