Design of an integrated oil cooled permanent magnet speed controller for energy-saving and emission reduction technological transformation decryption of electric motors

 Recently, there have been frequent policies in the field of energy conservation and emission reduction. General Secretary Xi Jinping called for the comprehensive promotion of green development at the National Ecological Environment Protection Conference, with a focus on adjusting the economic and energy structures, promoting comprehensive resource conservation and recycling, and achieving a circular chain connection between production and living systems.

Statistics show that China's energy utilization efficiency is only 33%, which is about 10 percentage points lower than developed countries. Among them, the average unit energy consumption of the main products in eight industries, including electricity, steel, non-ferrous metals, petrochemicals, building materials, chemicals, light industry, and textiles, is 40% higher than the international advanced level; The comprehensive energy consumption per unit product of steel, cement, and cardboard is 21%, 45%, and 12% higher than the international advanced level, respectively.

Permanent magnet speed regulator is a revolutionary new transmission method that utilizes Lenz's law, rare earth permanent magnets and alloy conductors, and adjusts the air gap between the permanent magnet disk and the conductor disk in a non-contact transmission mode to achieve free variation of motor output power, realize load equipment speed regulation and energy saving, and is a pure mechanical equipment that does not require electricity at all.

The average energy-saving efficiency of permanent magnet transmission energy-saving technology is over 15%, which can play an important role in the energy-saving transformation and consumption reduction of industrial enterprises' motors. However, there are multiple technical implementation routes for permanent magnet speed controllers. From the perspective of market usage over the years, in terms of supporting high-power loads and operating stability, disc type, symmetrical structure, and oil cooled permanent magnet speed controllers are currently a technology faction with excellent comprehensive performance in practical performance, supporting power (up to 5000kW), and operating stability.

       The oil cooled permanent magnet governor consists of an outer sleeve, a permanent magnet equipment body, an electric actuator, and other components. The permanent magnet equipment body is connected to the load shaft by a high-precision permanent magnet rotor assembly (containing high-strength permanent magnets), and to the motor shaft by a composite conductor rotor. There is no physical (mechanical) connection between the outer rotor and the inner rotor. The entire permanent magnet equipment is installed inside a sealed outer sleeve, and during operation, it is supplied with oil by a lubrication station to spray on the main body of the permanent magnet equipment for cooling and lubrication.

       The body of the oil cooled permanent magnet equipment and the cooling oil station are two separate devices. The pipelines between the oil station and the permanent magnet body are numerous and complex. During installation, in addition to the installation space of the permanent magnet body, a relatively large space needs to be provided for the cooling oil station. The product integration and space utilization are low, which not only occupies more installation space, but also increases the overall installation and renovation time and difficulty. 

       In order to solve the above problems, the R&D team from Wofu Permanent Magnet has designed an integrated oil cooled permanent magnet governor, which is an integrated oil cooled permanent magnet governor that integrates permanent magnets and lean oil stations. The integrated oil cooled permanent magnet governor integrates the cooling system of the permanent magnet body into a single device, optimizing the oil circuit, pipeline, and equipment cooling to form a compact and highly integrated integrated oil cooled permanent magnet governor.

At present, the electricity consumption of domestic motor systems in China accounts for about 60% of the national electricity consumption, and various load equipment such as fans and pumps driven by motors that are suitable for speed regulation and energy conservation account for about 60%, with a total of about 47 million units and a total installed capacity of about 35000MW. Compared with other energy-saving speed regulation devices, the energy-saving benefits of using oil cooled permanent magnet speed controllers for motor energy-saving and emission reduction technology renovation are very considerable, and general renovation projects can achieve energy-saving effects of 20% -50% or more.

Oil cooled permanent magnet governors have been widely promoted and applied in industries such as power and petrochemicals. The emergence of integrated oil cooled permanent magnet governors has been widely promoted and applied in various industries. For the whole society, the energy-saving potential of improving the operating efficiency of fan and water pump systems can reach 30-50 billion kW • h/year, which is equivalent to the annual power generation of 6-10 large-scale thermal power plants with an installed capacity of 1000MW. It meets the comprehensive resource conservation needs and responds to the call for national energy conservation and emission reduction. It has high practical and practical significance for establishing a sustainable ecological environment and achieving a harmonious society.