The use of frequency converters and their economic efficiency in the elevator industry

Improve driving comfort, ensure high stopping accuracy and quietness, increase the operating time of mechanical equipment and reduce power consumption by up to 60% - all this becomes possible thanks to the use of a frequency-controlled electric wire of the lifting winch (device) of the elevator

Each year, the use of elevator equipment consumes more than a billion kilowatt-hours of energy, so the elevator industry can be called an industry that has a large energy capacity

It is not surprising that the most important task at present is the introduction of modern energy-saving technologies while improving elevator equipment. Due to the systematic analysis of this information by installation, design and construction organizations, we can conclude that the introduction of various frequency-controlled electric drives, the main components of which is a  frequency converter, should be considered as a basic program for saving energy on elevators

The use of a frequency converter will allow for a complete adjustment of the rotation speed. Such an adjustment, in turn, will allow: 

• most often to abandon the use of gearboxes, variators, throttles and other control equipment. This will lead to a significant simplification of the mechanical system, increase its reliability, as well as reduce operating costs

• reduce the load on the engine and mechanisms, increase their service life with the help of a soft start of the engine, without various kinds of shocks and starting currents

• ensure the operation of mechanisms for a large amount of time at reduced speeds with a decrease in cyclically dynamic and vibration loads on bearings, seals, electric motors and foundations of mechanisms, as well as a corresponding increase in their resources and overhaul life

The use of a frequency-controlled drive in the elevator industry will allow:

• thanks to smooth transitions between processes, increase the comfort performance when driving the cab and the long life of mechanical equipment 

• due to the strong reduction of dynamic loads in various elements of the kinematic chain, reduce the operating costs associated with the overhaul of equipment

• due to a significant decrease in the rotating masses of the winch, reduce the consumption of electrical energy, thereby eliminating involuntary losses during transient starting-braking modes

Due to energy savings, the following indicators of economic efficiency of the use of frequency converters in the elevator industry are achieved (data are given for a  11 kW motor installed in a business center):

- Daily energy savings is 16.3 kWh, annual - 5930 kWh per year

- Consumed electrical energy:

а) Variable frequency drives 12 kW/h per day, 4380 kW/h per year

b) Drives of unregulated type 28.5 kW/h per day, 10402 kW/h per year

- The average machine operating time of the elevator is 6.8 kW / h per day, 2482 kW / h per year ;              

- The average number of launches per hour is 108

The annual average energy savings on each elevator with a frequency-controlled type electric drive exceeds 6 thousand kW / h Delta Electronics produces special converters of the VFD-VE series, which have the best quality-price ratio in the industry, for the purpose of using winches and lifting mechanisms