Electrical motors are one of the most utilised items employed by plants. A key design issue is removing unwanted heat caused by winding and core losses in the motor. This paper investigates the incorporation of a new technology, Thermoelectric Electric Coolers (TEC) to improve the heat flow from the core and casing to the surrounding air. Three test configurations are used. The first one is the heat sink system because of its simple construction arrangement capable of being simply adapted to a motors external casing. The second one is the heat displacement system “heat pipes” because of very large number of motors mounted in confined areas and the third one is the water-cooled heat sink arrangement extensively used in critical areas. The aim of this study is to evaluate the incorporation of TEC to each of these systems to remove unwanted heat more than the current systems. Experimental results show that the addition of the above systems with TEC reduce slot temperatures by 14.9%, 12%, and 18.96%, respectively. The reduction in insulation temperatures will result in increased motor insulation life or allow the motors to be overloaded (increased output) without exceeding insulation thermal ratings.

Cooling by Peltier Effect and Active Control Systems to Thermally Manage Operating Temperatures of Electrical Machines (Motors and Generators)

Electrical motors are one of the most utilised items employed by plants. A key design issue is removing unwanted heat caused by winding and core losses in the motor. This paper investigates the incorporation of a new technology, Thermoelectric Electric Coolers (TEC) to improve the heat flow from the core and casing to the surrounding air. Three test configurations are used. The first one is the heat sink system because of its simple construction arrangement capable of being simply adapted to a motors external casing. The second one is the heat displacement system “heat pipes” because of very large number of motors mounted in confined areas and the third one is the water-cooled heat sink arrangement extensively used in critical areas. The aim of this study is to evaluate the incorporation of TEC to each of these systems to remove unwanted heat more than the current systems. Experimental results show that the addition of the above systems with TEC reduce slot temperatures by 14.9%, 12%, and 18.96%, respectively. The reduction in insulation temperatures will result in increased motor insulation life or allow the motors to be overloaded (increased output) without exceeding insulation thermal ratings. 

Cooling by Peltier effect and active control systems to thermally manage operating temperatures of electrical Machines (Motors and Generators)

Symulacja maszyny synchronicznej z magnesami trwałymi

There is a strong general demand for the permanent improvement of electrical machines. Nowadays, these are at their near maximum potential, and even small further improvements can only be achieved with great effort and high cost. The single solution should be a paradigm shift in their development, by using radically new approaches to topology, materials, and fabrication. Therefore, the application of diverse 3D printing techniques for advanced fabrication in this field is inevitable. Therefore, these new approaches are receiving a great deal of attention among electrical machines designers. In the paper, the possible applications of these new fabrication technologies in the field of electrical machines are surveyed. The focus is set on emphasizing the advancement over the traditional manufacturing approaches.

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The Key Role of 3D Printing Technologies in the Further Development of Electrical Machines

Power flow in three-phase distribution grids containing single-phase prosumer voltage sources strongly depend on the RMS value of the voltage of these sources and their phase shifts in relation to the grid voltage. The ideal way to control single-phase prosumer sources should guarantee no return active power to the MV grid through a distribution transformer and no additional reactive power flows in the LV grid. This means that the active power of one-phase voltage source is consumed by other single-phase customers (in the same phase or in others phases) and the reactive power of this source is equal zero. The paper presents the results of the investigations of the dynamic control system a single-phase voltage source which allows meeting these conditions. On the basis of steady states calculations, static characteristics of the above mentioned control, needed to determine of the proper working point of a prosumer source were also obtained. Control process is as control of the RMS value and phase angle of the voltage source against the phase voltage of the LV grid, to which the source is connected, with simultaneous control of the current phase angle issued by the power source against voltage. The obtained results of dynamic simulations and static calculations would help to develop an area-wide uniform algorithm to control prosumer sources.

Control of prosumer voltage sources in distribution grids

Modelowanie maszyn elektrycznych z magnesami trwałymi

The co-operation of single-phase, prosumer power sources with three-phase grid powered by a distribution transformer Medium Voltage / Low Voltage (MV/LV), depends on the transformer windings arrangement and the control of the prosumers inverters. In the paper, the influence of the transformer windings arrangement on the flow of active power in a three-phase grid is discussed and the inverter control is shown, limiting the return of active power to the MV grid by the transformer. The control also reduces the power losses in the transformer and power losses in the MV grid. The transformer winding arrangement was chosen because of the possibility of transforming the energy from a single-phase prosumers source to the loads connected to the other phases of the transformer's LV side. Inverter control system was studied by simulation. Analysis and experiments are carried out to verify the effectiveness of the proposed solution.

Control of prosumer energy sources in power grid feeded by three-phase distribution transformer

The article presents a concept for a new design of the well-known Transverse Flux Machine (TFM) made with the use of a flat core used in classical electrical machines. The proposed design was first analytically verified and was subsequently verified using the finite element method, which fully corroborated the results. The simulations show that a set of three single-phase TFM machines with slotted flat rotor yokes generates a torque over three times greater than that of an induction motor and twice as large as Fractional Slot Concentrated Winding—Permanent Magnet Synchronous Machines (FSCW-PMSM). The performed comparative calculations confirmed that the torque generated by machines operating on principles similar to TFM can generate a torque much greater than those currently in common use.

Tomasz Drabek

Papers

Modelowanie maszyn elektrycznych z magnesami trwałymi

Symulacja maszyny synchronicznej z magnesami trwałymi

Control of prosumer voltage sources in distribution grids

Control of prosumer energy sources in power grid feeded by three-phase distribution transformer

A Novel Approach to Transverse Flux Machine Construction