Ultra Premium Efficiency (IE5) magnet-free synchronous reluctance motor

 Research and Development company EMACH specializes in the development of energy-efficient electric motors and generators for electric machines manufacturers. Main types of motors designed by EMACH are synchronous reluctance motors and flux reversal motors. Synchronous reluctance motors are described below.

More than 60% of electric energy in industry is consumed by induction motors. The efficiency of the induction motors is low due to high rotor losses. Company EMACH has developed an efficient magnet-free synchronous reluctance motor  (SynRM) which efficiency significantly exceeds efficiency of induction motors as well as of other motors.   The results of the experimental comparison of the SynRM developed by the company EMACH and motors of other manufacturers are presented below.

Table 1. The characteristics of 1500 W, 3000 rpm motors

Motor type

Induction motor

Magnet-free SynRM

Motor with magnets

Magnet-free SynRM

Manufacturer

ABB

ABB

Hyosung

EMACH

Rated efficiency, %

84

87.9

89.3

90.7

Efficiency class

(New standard IEC 60034-30-2)

IE3

IE4

IE5

Much higher than IE5

Weight, kg

15.5

13

7.5

13

  EMACH’s SynRM has lower manufacturing cost due to absence of squirrel cage and has 2.5 kg (19 %) lower weight than ABB’s induction motor. Also EMACH’s SynRM production cost is much lower than of Hyosung’s synchronous motor with rare-earth magnets due to absence expensive of magnets in motor design.

  The IE efficiency class levels of 1500 W, 3000 rpm motors according to the standard IEC 60034-30-2 «Rotating electrical machines – Part 30-2: Efficiency classes of variable speed AC motors (IE-code)» are as follows: IE2=81.3 %, IE3=84.2 %, IE4=86.5 %, IE5=88.9 %. The rated efficiency of the EMACH’s SynRM is much higher than rated efficiency of ABB’s and Hyosung’s motors and much higher than efficiency of IE5 class level.

Figure shows the experimental comparison of the EMACH’s SynRM (green line) with the ABB’s induction motor (blue line), ABB’s SynRM (purple line) and Hyosung’s motor with magnets (red line) at the pump load (quadric dependence of torque on speed). As it can be seen the EMACH’s SynRM efficiency has highest efficiency among all motors considered here in wide range of speed and power.        

  The efficiency of the motors was measured according to IEC 60034-2-3 "Rotating electrical machines – Part 2-3: Specific test methods for determining losses and efficiency of converter-fed AC induction motors" (Method 2-3-C: Input-output method).                                                                           

Table 2. Characteristics of 1500 W 3000 rpm motors 

Motor type

Induction motor

Magnet-free SynRM

Motor with magnets

Magnet-free SynRM

Manufacturer

ABB

ABB

Hyosung

EMACH

Eff1,% (torque 100%, speed 100%)

84

87.9

89.3

90.7

Eff2, % (torque 50%, speed 75%)

83.5

84.3

86.9

90.5

Eff3, % (torque 25%, speed 50%)

75.4

79.1

78.5

90.2

In table 2    Effis the efficiency at the rated speed and the rated torque, Eff2 is the efficiency at the speed equal to 75% of the rated speed and the torque equal to 50% of the rated torque, Eff3 is the efficiency at the speed equal to 50% of the rated speed and the torque equal to 25% of the rated torque.

So EMACH’s SynRM efficiency succeeds the SynRM efficiency of other manufactures not only at rated point but also at underload conditions.

High values of efficiency has been reached due to unique rotor geometry including the form of flux carrying paths and flux barriers. The magnet-free SynRM technology developed by EMAСH is protected by the patent.

The magnet-free SynRMs can replace the induction or permanent magnet synchronous motors and can be applied in variable speed applications such as pumps, fans, compressors, extruders, conveyors, mixers, electric vehicles, power tools, household appliances, servo drives, electric spindles etc.

EMACH can develop magnet-free synchronous reluctance motor in the various housing (general-purpose, explosion-proof or any housing chosen by client) in wide range of power.