New Mitsubishi EV motor Smaller and more efficient

[MitchJi]

Hi,

New EV motor from Mitsubishi Electric increases efficiency, reduces size

PRESS RELEASE

Mitsubishi Electric Develops EV Motor System with Built-in Silicon Carbide Inverter

Industry's smallest inverter-equipped EV motor system is half the dimensions of existing systems

Tokyo, March 8, 2012 - Mitsubishi Electric Corporation (TOKYO: 6503) announced today it has developed a prototype electric vehicle (EV) motor system with a built-in silicon carbide inverter. The EV motor system is the smallest of its kind, measuring just half the dimensions of Mitsubishi Electric's existing motor system that uses an external inverter, and loss is below half that of silicon-based systems.

The new motor system is expected to enable manufacturers to develop EVs offering more passenger space and greater energy efficiency. The company plans to commercialize the motor system after finalizing other technologies for motor/inverter cooling, downsizing and efficiency.

The global demand for EVs and hybrid EVs (HEVs) has been growing in recent years, reflecting increasingly strict regulation of fuel efficiency and growing public interest in saving energy resources and reducing carbon dioxide emissions. As EVs and HEVs require relatively large spaces to accommodate their robust battery systems, there is a strong need to reduce the size and weight of motor systems and other equipment to ensure sufficient room in passenger compartments.

Key Developments of New EV Motor System
1) Inverter-equipped design just half the dimensions of existing system
• Mitsubishi Electric's existing system consists of separate motors and inverters driving the motors, which requires more space for these components and their wiring.

• The newly developed cylinder-shaped inverter matches the diameter of the motor, enabling them to be connected coaxially within a chassis, resulting in a substantial downsizing of the motor system.

2) SiC inverter loss is reduced by more than 50% compared to silicon-based systems
• Silicon chips have been widely used in power devices for inverter switching. Silicon carbide, however, is now recognized as a more suitable material for chips owing to its electrical characteristics, including a breakdown electric field that is 10 times greater compared to silicon chips. This greater breakdown electric field enables thinner chips, which reduces electrical resistance and lowers loss.

• All power chips in the inverter are silicon carbide-based, resulting in over 50% reduction of loss compared to the company's silicon-based inverter system.

3) Improved winding density and magnetic efficiency achieve smaller motor with higher output
• The motor is a permanent magnet motor that uses a neodymium magnet. Mitsubishi Electric's proprietary dense-winding structure enabled the company to utilize its poki-poki motor production technologies to reduce the size of the motor.

• The size and configuration of the stator and rotator poles were optimized using Mitsubishi Electric's high-level magnetic-design technology. As a result, magnetic efficiency was increased and power output was improved by 5% over previous motors.

 

[Lock]

Mitsubishi Electric's proprietary dense-winding structure...

Had to go look that up... here maybe:
http://www.google.com/patents?id=Ti...a=X&ei=ZtxfT_K3KuHf0QH3k-WkBw&ved=0CDsQ6AEwAg

DISCLOSURE OF THE INVENTION Problem to Be Solved by the Invention

[0004] However, as for example in a stator core 104 shown in FIG. 25, when each slot 105 is tapered so that the distance W2 between both the side surfaces 109, 109 of the slot 105 gradually decreases with approach from the bottom 1 07 to the distal opening 108 of the slot 105, a magnet wire 141 having a constant width W1 over the length thereof produces large gaps S from both the side surfaces 109, 109 particularly in the vicinity of the bottom 107 of the slot 105. Therefore, the magnet wire 141 carmot be placed in the slot 105 so that it can attain a high space factor.

[0005] In view of the above, an object of the present invention is to provide a linear material suitable as a magnet wire attaining a high space factor in each slot of a stator core. Furthermore, another object of the present invention is to provide a stator structure in which such linear materials are applied as magnet wires and fitted on a stator core.

Means to Solve the Problem

[0006] To attain the above objects, a linear material according to the present invention is a linear material of rectangular cross section in which an insulating coating is formed on the outer surface of a metal wire, the linear material changing the width continuously or stepwise over the length thereof. [0007] The linear material may be formed so that the transverse cross-sectional area of the metal wire is constant over the length thereof.

[0008] A stator structure according to the present invention includes: a stator core having a large number of concave slots and a large number of convex magnetic poles circumferentially alternately arranged; and magnet wires of rectangular cross section in each of which an insulating coating is formed on the outer surface of a metal wire, wherein each of the slots is formed so that the distance between both the side surfaces of the slot gradually decreases from the bottom to a distal opening of the slot, each of the magnet wires is wound around the associated magnetic pole and inserted in tiers in the associated slot, and the magnet wire is placed in the slot so that the width thereof continuously or stepwise decreases from the bottom to the distal opening of the slot.

[0009] The magnet wire may be formed so that the transverse cross-sectional area of the metal wire is constant over the length of the metal wire.

EFFECTS OF THE INVENTION

[0010] The present invention exhibits the following significant effects.

[0011] According to a linear material (magnet wire) and a stator structure according to the present invention, the width of the magnet wire to be inserted in tiers in each slot (concave groove) of a stator core of a motor can be configured according to the width of the slot. Thus, the magnet wire can be placed in the slot with little gap left in the slot, thereby significantly increasing the space factor of the magnet wire in the slot. This enables the production of a motor that can efliciently obtain large rotational torque. In other words, a motor with a small size can attain equivalent torque to that of conventional motors. This provides a motor reduced in size and weight and in turn attains energy saving.

 

[Hillhater]

I guess someone needs a new , smaller, more powerful, motor..?
..but EVERYONE needs a new , smaller, more powerful, BATTERY !

 

[jonescg]

A smaller more powerful motor suits me and my applications - just leaves room for more batteries anyway...