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Eco-efficient solutions that get you where you need to be

KONE Corporation
KONE was the first company to offer regenerative drives for high-speed elevators with gearless async motors over two decades ago. It was also the first again – in 2009 – when it launched high-performance regenerative drives combined with its advanced KONE EcoDisc® machines for a full range of applications, from low-speed elevators to high-speed units designed for the world’s highest buildings.

Advanced elevator technology offers some major opportunities for saving energy and helping keep operating costs as low as possible. To really deliver here, however, systems need not only to be inherently energyeffi cient, they must also be capable of handling power surges and not be affected by or affect other electrical equipment.

KONE set the standard in energy-efficiency for the high-speed elevators used in high-rises, and has now brought these benefits to low- and mid-rise buildings.

KONE was the first elevator company to really realise the importance of energy efficiency when it introduced its permanent magnet synchronous motor technology. These motors use up to 70% less energy and have a 30-40% lower peak starting current requirement than traditional solutions. KONE was also the first company to offer regenerative systems, which recover up to 35% of the total energy used by an elevator system.

They do this by converting the excess energy generated when full cars descend or empty ones ascend into electrical current and feeding it back into a building’s electrical network or the grid. This eliminates the braking energy that normally goes to waste and has to be dissipated using braking resistors, which in turn need to be cooled or provided with ventilation.

KONE set the standard in energy-efficiency for the high-speed elevators used in high-rises, and has now brought these benefits to low- and mid-rise buildings.

Designed for an energy-conscious world

KONE’s high-speed, high-capacity regenerative drives offer maximum performance for mid- to high-rise structures, such as residential, office, and public buildings.

Designed to work with KONE EcoDisc® machines, solutions for high-speed elevators offer speeds up to 10 m/s, carrying loads up to 1,600 kg, and can handle up to 240 starts/h. Those for mid-rise buildings offer speeds up to 3 m/s with similar load and start capacities, while those for low-speed installations offer a speed of 1.6 m/s, carrying a maximum of 630 kg, and 1.0 m/s carrying 1,000 kg, and can handle up to 180 starts/h.

Electromagnetic interference and harmonic distortion are kept well below code requirements, resulting in very ‘clean’ regenerated power.

Depending on building height and elevator speed, energy savings of between 20% and 35% can be achieved using KONE’s regenerative solutions.

KONE drives also offer extremely accurate stopping and can be programmed to match a customer’s specific acceleration/jerk values and target ride comfort very closely. KONE drives use Modulated Line Bridge technology to make the counterweight or car act a motor and a KONE EcoDisc® as a generator, while a regenerative drive recovers this energy and converts it into electricity for use in other applications, such as lighting or to drive other elevators.

Sophisticated converter technology allows for a minimum line current and power factor of 0.95 or better, enabling peak power demand to be reduced by 30-40% during acceleration and making it possible to reduce the size of fuses, cabling, and generators.

A KONE regenerative drive, coupled with a KONE EcoDisc® motor, results in a less costly installation, reduced power consumption on a day-to-day basis, and significant savings over many years of reliable operation.

Benefits for all types of buildings

KONE regenerative technology offers energy-saving solutions for high-speed, mid-range, and low-speed elevators – in terms of economy and seamless integration with the power supply:

  • Energy savings of up to 35% can be achieved thanks to regeneration in high-speed use, up to 30% in mid-range elevators, and up to 20% in low-speed installations
  • Systems have a low-amp requirement when starting up and a low kWh requirement when running
  • Low harmonic distortion, low electromagnetic interference, and high undervoltage tolerance guarantee minimum power supply issues.

A better ride

In addition to significantly better energy performance, KONE’s regenerative solutions also offer top-quality ride comfort, which is a particular plus in mid- and high-rise buildings.

They do this by offering optimum speed and acceleration curves, thanks to acceleration and deceleration pro les that can be closely tailored to meet local expectations, while still optimising overall energy performance.

Elevator motor torque and speed are kept under close control to eliminate resonance in the sheave and resulting vibration.

Ultra-precise speed and position measurement provides exact position feedback for position controllers, while a top car encoder measures actual car movement to eliminate rope elongation effects in high-rise buildings. A highspeed positioning system xed to landing doorsills guarantees floor levelling within a margin of +/- 2 mm.

> Simon Barrette
(Published in HighTech Finland 2010)