Energy Savings Through the Use of Frequency Converters
In the industrial, residential sector, construction, and public services, the use of various types of drive equipment leads to significant electricity costs. Constant maintenance, repair, and adjustment of motors require setting rotation speeds, which often necessitates adjustments to the supply voltage or the use of mechanical variators and frequency converters. However, some traditional control methods have their downsides:
- - limited regulation range;
- - unreasonable application;
- - complexity in operation.
Advantages of Modern Frequency Converters
Modern frequency converters increase the efficiency (COP) up to 98%, making them extremely effective when used in automatic control systems:
- - transport mechanisms and conveyor belts;
- - lift units, hoists, and cranes;
- - pumping, smoke extraction, and ventilation systems.
Thanks to their application, savings are increased on existing units, unnecessary elements are eliminated, smooth acceleration and deceleration are achieved, speed is regulated, and the operational life of mechanisms is extended. The economically justified use of frequency converters can be illustrated by simple calculations.
Example Calculation of Electricity Savings
Let’s consider a system for pumping water that operates under stable loads. Our company recommends using Bosch vfc5610 frequency converters with a power of 75 kilowatts. The electricity savings when using converters is approximately 35-45%, with an average value of 40%.
Let’s calculate the energy consumed with the frequency converter over a year:
E (kilowatt-hours) = P * 40% / 100 * T1 * T2 * T3 = 75 * 40% / 100 * 24 * 30 * 12 = 259200 kilowatt-hours,
where:
- P – power of the drive mechanism;
- T1 – number of working hours per day;
- T2 – reserve factor;
- T3 – number of months in a year.
The cost of consumed electricity in Ukraine (for example, in Kyiv) is 1.7 UAH/kW, so the annual cost will be:
Cost = 259200 * 1.7 = 440640 hryvnias per year.
The payback period of the frequency converter will be: 100000 / 440640 = 0.24 years (approximately 5 months).
Thus, at a price of Bosch vfc5610 R912005971 frequency converter at 100000 UAH, its payback period will be approximately 4.5 months.
Considering Downtime in Production
If we assume that the pumping equipment will be idle one day a week, and for a year the system will stop for a month, then the calculations will look like this:
E = 75 * 40% / 100 * 24 * 26 * 11 = 205920 kWh per year.
Cost for electricity: 205920 * 1.7 = 350064 UAH per year.
Payback: 100000 / 350064 = 0.28 years (approximately 5 months).
Given the rare mode of operation, an increase in the payback period is possible. However, when using many such facilities, the savings will be greater than projected. If needed, our specialists can conduct calculations and select frequency converters according to the technological and operational characteristics of your production.