Electric Motors


PowerSines pioneered the market in the development of motor drives and soft starts for electric motors. Leveraging 20 years of R&D and engineering experience, plus an in-depth understanding of AC motor design, PowerSines has invented an innovative method for controlling efficiency of AC motors based on utilization of voltage vectors in 3-phase electric systems.

The Voltage Vector Combination (VVC) controls voltage and power supply to AC motors keeping pure sinusoidal waveform, thus enabling energy efficiency and motor improvements.

Electric motor efficiency techniques currently offer the biggest potential for energy savings while improving efficiency of motor components and systems.

  • Add production capacity with no increase to electrical consumption
  • Add more machinery on same infrastructure
  • Improve motor start up using pure sinusoidal voltage and eliminate the need for VSD
  • Reduce maintenance costs and replacement parts
  • Simple installation with no programming or set up required

As a pioneer in motor technology, the family of Soft Starters from PowerSines continues to be used and sold to loyal customers. 

PowerSines electric motor control solution sold under the SinuMEC brand,  is a new category of AC motor controller that uses Sinusoidal voltage control to save energy and improve operations. The SinuMEC uses the patented V V C technology to provide complete electric motor efficiency and energy savings. The SinuMEC product is designed to work with AC motors running at constant speed while carrying variable loads. 




A Sinusoidal Motor Efficiency Controller

SinuMEC, the Sinusoidal Motor Efficiency Controller, is a multifunctional controller for constant speed, variable load AC motors.  SinuMEC is built around power transformers controlled by microprocessor. This patented VVC technology enables dynamic control of the voltage level and power consumption according to the escalator motor load conditions, reducing losses and saving energy. 

Unlike Soft Starters and VSDs that alter sinusoidal waveform or change frequency, generating harmonics and electromagnetic interferences- SinuMEC supplies a pure sinusoidal waveform to the motor and guarantees smooth motor start and energy savings improving power quality and reliability. 

Here is a typical escalator scenario, with energy efficiency provided by SinuMEC:
The fact that even at rush hour where a typical escalator is loaded only about 50%, SinuMEC is able to reduce the voltage and improve motor performance, since it automatically detects the partial load and adjusts the voltage accordingly.  When the number of riders on the escalator decreases, SinuMEC reduces voltages levels even further improving motor performance. In a typical scenario, such as this one, the total energy savings for escalators with SinuMEC can reach between 10–25%.

In a typical escalator application, SinuMEC provides energy savings of 10-25%, an ROI of around two years and overall reduction of 50% on motor Life Cycle Cost (LCC).

SinuMEC Advantages for Escalators:

  • Reliable and Robust
    A heavy-duty motor efficiency controller that can work in harsh electric environments, such as public transportation sites, where accelerating or slowing down electric trains generates severe electrical disturbances
  • Re-generative Energy
    Uniquely designed to cope with re-generative energy, due to a down-loaded escalator, returning the energy back to the network without any additional filters or bypasses
  • Improved Power Quality
    SinuMEC has a very low THD and unlike VSDs it does not require any additional filters for suppressing harmonics
  • Motor Starter
    Smooth motor starting with typical startup current at only 2 x the nominal, thereby reducing electric stress on the motor and electric network;
    Continued monitoring of motor performance improves electric efficiency while motor is running 

SinuMEC Energy Savings for Escalator Motors:

  • Reduced direct kWh reading by 10% to 25%
  • Reduced network losses by up to 75% (equaling 5% from kW)
  • Reduced reactive energy by 50% (which saves around 2% from kW due to capacitors self losses and harmonics increase)
  • Reduced motor waste heat; reduces air conditioning costs by up to 20% (equiv. 1%  of kW)

Optimizing energy efficiency in escalator motors

Problems Associated with Changing Escalator Speed:

Using sensors to switch escalators into “intermittent” or “sleep” modes in order to reduce energy consumption is not a relevant solution for retail and busy transportation sites. For example, in shopping malls, department stores, subways and train stations, where escalators are in constant use, savings cannot be generated by simply changing the motor speed. Not only is the solution not efficient it also causes a negative customer experience and generates a poor perception of business’ operation. 


SinuMEC – The Ideal Solution:

SinuMEC is a Sinusoidal Motor Efficiency Controller, it is a multifunctional controller for constant speed, variable load AC motors. It dynamically controls the voltage level and power consumption according to the escalator motor load conditions, and as a result it reduces losses, saves energy and extends the equipment lifetime.

In a typical escalator application, SinuMEC provides between 10-25% energy savings, an ROI of around two years and overall reduction of 50% on motor Life Cycle Cost (LCC).

Market Needs - Escalators

The Misconception

Escalators play an essential function in commercial facilities and public transportation locations. They operate continuously providing easy accessibility to all parts of the business site.

Typically each escalator strip is equipped with a 7.5 – 15KW inductive AC motor, which operates long hours and consumes a significant amount of electricity. The solution of using sensors for “intermittent” or “sleep” modes to reduce energy consumption has very limited applicability. This approach is not suitable for shopping malls and department stores, where escalators are in constant use, leaving no opportunity for long enough “intermittent” intervals to generate reasonable savings. And, in fact, slowing or stopping escalators will actually cause a negative customer experience and poor perception of the business.

A similar situation occurs in busy public transportation sites, such as subways and train stations, where people are continuously entering and exiting the station. These conditions force escalators to be in constant motion, nearly without any ‘intermittent’ intervals where energy savings can be implemented by the stopping or slowing down the escalators.

The solutions for changing escalator mode do not meet the market requirements to save energy.


The Right Approach

The typical design of AC motors for escalators assumes the worst-case scenario, whereby an escalator is fully loaded, which may be with two riders per step. Realistically the fully loaded scenario is seldom the case, since escalators usually operate with fewer riders.  As a result, the escalator motor are partially loaded and in this mode they are inefficient, wasting energy, with high copper and iron losses, and a low Power Factor.

The efficiency of partially loaded AC motors can be improved and losses can be decreased by reducing the voltage level supplied to the motor.  

PowerSines has developed the new generation of motor controllers (SinuMEC) that enable improving the energy efficiency of escalators without changing its speed or stopping it.