Polish Ministry of State Treasury

Prestigious order for Yaskawa

Polish company Sterdzwig has received the contract to progressively retrofit the lift installations at the Warsaw Ministry of State Treasury with Yaskawa regenerative lift drives. This will dramatically reduce the total energy consumption of the building.

Depending on the load, energy is generated whenever a lift is in operation. In the case of conventional drive solutions this energy is lost as surplus braking energy or waste heat. The D1000 feeder and regenerative inverter unit enable the feedback of regenerative energy into the network. The energy is thus available to other consumers in the building, e.g. for lighting, and these consumers do not need to draw it from the mains supply. This significantly reduces the total electrical energy requirements, preserves the environment and cuts operating costs. According to measurements on the lifts at the Polish Ministry of State Treasury, the amount of recovered energy is equal to 74% of the consumed energy.

Efficiency by regeneration

Particularly in lift installations, the use of the D1000 in combination with Type L1000A frequency inverters produces ideal results. In a duplex system, as in Warsaw, two of these inverters are coupled in the intermediate circuit and fed by a D1000 unit. The inverters can exchange energy directly with one another or feed it back to the system.

Due to the elimination of conventional braking transistors and resistors, the D1000 requires less space and maintenance expenses are reduced. In addition, the inverter enables a sinusoidal current input. It thus reduces the load on transformers and other parts of the power supply thanks to lower harmonics. Reliable system operation is thus possible with fluctuating input voltage, as intermediate circuit stabilization compensates for such fluctuations.

The D1000 is available for mains voltages of 200 and 400 V AC in a power range from 5 to 630 kW. It is ideally suited for multiple inverters or servo axes in a DC link system or for one-to-one applications. Applications are to be found not only in passenger and freight lifts, but also in cranes, escalators, test rigs and winder applications.

Lift-specific frequency inverters

The L1000A offers all lift-specific advantages of the L1000 series over a wide power range from 1.5 to 110 kW. It enables the operation of both asynchronous and permanent-magnet motors with speed sensor and can satisfy the highest standards of riding comfort and stopping accuracy. The installed SIL3 STO function permits operation without travel contactors.

In addition, the L1000A incorporates brake monitoring according to EN 81-1 A3 and a DCP interface for controller connectivity. With its diverse control options the L1000A can be combined with virtually any lift control system. Thanks to a plain text display in lift terminology and units, commissioning entails relatively little time and effort. The menu provides a choice of 13 languages.