Design criteria for water cooled systems of induction machines

Multidisciplinary analysis of a 750 kW PMSM for marine propulsion including shock loading response

“…In view of the above, the principal criteria followed in the design of the water-jacket, besides dimensional constraints, are listed below [29]:…”

“…In this regard, the analysis of this cooling arrangement is not very common in the literature [35], although some analysis of specific elements within the IC81W cooling system can be found [57–60]. Owing to manufacturing constraints, in all cases a bifurcated axial‐type water‐jacket has been considered even if it is known that solenoid‐type water‐jackets lead to lower pressure drops [29]. This choice results in the need to model the whole machine, without symmetries or periodicities, due to the appearance of axial and circumferential temperature gradients.…”

“…In this case, the pressure drop along the water‐jacket for a coolant flow rate of 75 l/min is lower than 0.1 bar, below the established limit of 0.5 bar (see Table 1). The employed coolant fluid is water–glycol 50–50, which has the following benefits over plain water: Contains anti‐corrosion additives, greatly reducing maintenance costs. Glycol systems are closed and dirt‐free, so no side stream or full‐flow filtration is required. However, in a 50% glycol solution, the specific heat capacity decreases by ∼20% compared to water, thus usually requiring an increase in the fluid flow. In view of the above, the principal criteria followed in the design of the water‐jacket, besides dimensional constraints, are listed below [29]: Achieve a turbulent flow along the whole water‐jacket to maximise the heat transfer between the coolant and the housing. Minimise the coolant temperature gradient between the inlet and the outlet in order to avoid inhomogeneous temperature distributions along the motor stack (Δ T coolant <5°C). For the physical setup, fluids (air and water–glycol) have been considered incompressible and have been modelled with the properties given in Table 3.…”

“…Moreover, experimentally validated analytical tools for the thermal analysis of different cooling arrangements for PM machines are available [22][23][24][25][26]. Furthermore, optimisation methods and design criteria for different cooling elements have been developed in the last years [27][28][29][30]. In this regard, this paper presents a comparative of the current trend in this sector based on the IC7XW cooling systems [31] (cooling through a water-jacket), which are replacing the widespread IC8XW systems (machine-mounted heat exchangers).…”

A Novel Thermal Network Model Used for Temperature Calculation and Analysis on Brushless Doubly-Fed Generator With Winding Encapsulating Structure

“…Another way can be adopted for motor is water cooling. Its cooling effect is found better than [18]- [22]. For the cooling ways introduced above, they both need auxiliary devices such as fan and water pump, which lead to a reduction in motor efficiency.…”