Two effects, one is the role of damping the power system to play the role of damping, the second is the stator winding negative sequence current generated by the reverse rotation of the magnetic field generated in the rotor induced current to provide access. The damping windings consist of damped teeth and damp strips forming a squirrel cage similar to an asynchronous motor. The principle is very simple is that once the stator magnetic field and the rotor magnetic field has a relative movement, will be generated in the squirrel cage induced current, the formation of additional magnetic field (from the damping effect).

General large and medium synchronous motor rotor, in addition to the excitation winding, but also equipped with damping winding. The damper winding is similar to the cage winding structure of the rotor of the cage type asynchronous motor. The whole damper winding consists of copper rods and short-circuit copper rings welded in the pole hole. The damping winding has two main functions:

(1) When the synchronous motor is started asynchronously, the asynchronous motor generates the asynchronous starting torque by using the induced current in the damper winding and the stator rotating magnetic field as the cage type asynchronous motor to start the synchronous motor. So that the damper winding is the starting winding.

(2) the relative movement between the rotor and the rotating magnetic field occurs when the synchronous motor is oscillating in the operation of the synchronous motor, and the induced current is generated in the damper winding, which interacts with the rotating magnetic field to produce a torque which prevents the rotor from rotating relative to the rotating magnetic field, Of the shock, which is the "damping" meaning.

June 1, led by the National Development and Reform Commission, 40 departments of the "People's Republic of China Sustainable Development National Report" (the "Report") published in Beijing, which is China's first national report on sustainable development. "The report summarizes the efforts and progress made by China's implementation of the sustainable development strategy since 2001, analyzes the gaps and challenges, and clearly sets out future strategic initiatives." Du Ying, deputy director of the National Development and Reform Commission, Say.

40 departments involved in the preparation of "report"

Du Ying introduced the United Nations Conference on Sustainable Development will be held June 20 to 22 this year in Rio de Janeiro, Brazil. This conference is an important international conference in the field of international sustainable development, following the World Conference on the Environment in 1992 and the Johannesburg World Summit on Sustainable Development in 2002.

"The Chinese government attaches great importance to this conference, approved by the State Council, in April last year, set up by the National Development and Reform Commission, Ministry of Foreign Affairs, Ministry of Science and Technology, Ministry of Finance, Ministry of Environmental Protection and other 29 departments jointly composed of the General Assembly of the Chinese Preparatory Committee "Said Du Ying.

This reporter learned that in the "report" in the preparation process, a total of 40 departments and related research institutions from the hundreds of personnel to participate in several departments, non-governmental organizations and the community's views and suggestions. The report has a broad public base that fully reflects the progress made in China's sustainable development over the past decade.

Improve the level of energy security

China through efforts to eliminate backward production capacity, strengthen energy conservation in key areas, and actively develop new energy and renewable energy and other measures to improve the level of energy security. "Report" said that over the past decade, China's energy self-sufficiency rate has remained at 90% or more, in 2010 the total energy consumption reached 3.25 billion tons of standard coal, energy self-sufficiency rate of 91.4%.

China's energy structure to coal-based, oil shortage, China's energy use and environmental protection has become increasingly prominent contradictions. As Du Ying said: "save energy, adjust the energy structure, the development of new energy is the inevitable choice for China 's sustainable development of energy.

"Report" also pointed out that China will build a resource-saving society as a strategic task of economic and social development, energy saving, rational development and utilization of mineral resources, strict protection of arable land and water resources as the focus, and actively promote the sustainable use of resources.

Key areas of energy saving achievements

In order to save energy resources, protect the environment and improve economic efficiency, the Chinese government has actively promoted energy conservation in key areas: the implementation of ten key energy-saving projects in industrial boilers, combined heat and power, and other key energy-saving projects to carry out energy conservation initiatives Consumption of energy-saving management, to promote energy audits and energy efficiency standards; in the field of manufacturing technology, the promotion of green design technology, energy saving and environmental protection of the new processing technology, industrial products, green dismantling and recycling remanufacturing technology to promote industrial production processes and product use The process of energy saving; in the field of building energy efficiency, to improve the implementation of new energy-efficient building standards, speed up the existing building energy-saving transformation, to promote renewable energy in the construction of large-scale application of the public office area for energy conservation.

For example, the Chinese government to implement the 2006-2010 10 key energy-saving projects, the central budget investment arrangements more than 80 billion yuan, the central government energy-saving emission reduction special funds to arrange more than 220 billion yuan, a total of more than 5200 key energy-saving projects. As of the end of 2010, the top ten key energy-saving projects accumulated 340 million tons of standard coal energy-saving capacity.

Another example is in the field of construction, to take to enhance the implementation rate of mandatory construction of new energy-saving standards to speed up the pace of existing energy-saving building to promote renewable energy in the construction of large-scale application of the public office area of energy-saving transformation measures The As a result of the multi-measures, as of the end of 2010, the national urban new architectural design stage of the implementation of energy-saving mandatory standards ratio of 99.5%, the construction phase of the implementation of energy-saving mandatory standards ratio of 95.4%.

Energy efficiency continues to improve

"Report" said that the Chinese government vigorously promote structural energy efficiency, optimize the industrial structure and spatial layout, eliminate backward technology, equipment and products, increase the advanced application of energy-saving technology to promote efforts to comprehensively strengthen energy management, energy efficiency in major energy-consuming industries year by year improve. Compared with 2005, the energy consumption of enterprises above designated size in 2010 decreased by 26%; the power consumption of thermal power was reduced from 370 g standard coal / kWh to 333 g standard coal / kWh, down 10% Energy consumption decreased from 688 kg standard coal to 605 kg standard coal, down 12.1%; cement comprehensive energy consumption decreased by 28.6%; ethylene comprehensive energy consumption decreased by 11.3%; synthetic ammonia comprehensive energy consumption decreased by 14.3%. Steel industry CDQ technology penetration rate increased to 80% or more, the new cathode aluminum electrolyzer, high voltage inverter, rare earth permanent magnet motor, plasma oil-free ignition and a large number of highly efficient energy-saving technologies and products are widely used.

DC brushless motor and general DC motor has the same working principle and application characteristics, and its composition is not the same. In addition to the motor itself, the former also more than a commutation circuit, the motor itself and the commutation circuit closely together. Many low-power motor motor itself is combined with the commutation circuit, from the appearance of the DC brushless motor and DC motor exactly the same.

DC brushless motor itself is the electromechanical energy conversion part of the DC brushless motor in addition to motor armature, permanent magnet excitation two parts, but also with a sensor. The motor itself is the core of the brushless DC motor, brushless DC motor is not only related to performance indicators, noise vibration, reliability and service life, etc., brushless DC motor also involves manufacturing costs and product costs. As a result of the use of permanent magnetic field, so that the brushless DC motor from the general design and structure of the DC motor to meet the requirements of a variety of application markets, DC brushless motor and the province of copper materials, manufacturing simple direction. The development of permanent magnet magnetic field is closely related to the application of permanent magnet material. The application of the third generation permanent magnet material makes the brushless DC motor move towards high efficiency, miniaturization and energy saving.

DC brushless motor in order to achieve the electronic commutation must have a position signal to control the circuit. Early use of mechanical and electrical position sensor to obtain the position signal, has been gradually using electronic position sensor or brushless DC motor to get the position signal, the easiest way is to use the armature winding potential signal as the position signal. DC brushless motor to achieve the motor speed control must have a speed signal. The speed signal is obtained by obtaining the position signal similar method. The simplest speed sensor is the combination of the frequency measuring generator and the electronic circuit. DC brushless motor commutation circuit by the drive and control of two parts, these two parts are not easy to separate, especially low-power circuit is often integrated into a single dedicated ASIC.

DC Brushless Motor In the power of the larger motor, the drive circuit and control circuit can be integrated into one. The driving circuit outputs the electric power, drives the armature winding of the motor and is controlled by the control circuit. At present, the DC brushless motor drive circuit has been converted from the linear amplification state to pulse width modulation of the switch state, the corresponding circuit components from the transistor discrete circuits into modular integrated circuits. Modular integrated circuit with power bipolar transistor, power FET and isolation gate field effect bipolar transistor and other forms of composition. Although the isolation gate field effect bipolar transistor is more expensive, but from the point of view of reliable safety and performance, the choice of DC brushless motor is more appropriate.

Basic manufacturing equipment areas: with the "high-end CNC machine tools and basic manufacturing equipment," the implementation of major scientific and technological projects, focusing on strengthening high-precision, high-speed, intelligent, composite, heavy-duty CNC machine tools and special processing machine tools, large CNC forming stamping, heavy forging, cleaning Efficient casting and heat treatment equipment standards and research and development.

Key components of the field: focus on strengthening large, high-speed, precision bearings, high-performance, high reliability hydraulic components and systems, high-power high-reliability gears and chain drives, high-strength fasteners and other high-end base parts standards research and Development; around the "accelerate the development of sensors and intelligent instrumentation industry development action plan (2013-2025)" to promote the standardization of sensors and intelligent instrumentation work.

Intelligent manufacturing equipment field: with the "intelligent manufacturing equipment industry development special" implementation, focusing on strengthening the digital workshop (factory) and sensors, measuring instruments, transmission and execution devices, control systems, industrial robots and other intelligent core device standards research and development.

Energy saving and environmental protection equipment: focus on strengthening the prevention and control of heavy metals in water and soil, municipal solid waste and industrial solid waste reduction, waste electronic equipment reduction and harmless equipment, livestock and poultry manure regeneration equipment, waste heat recovery Devices and other standards of research and development.

Modern agricultural equipment: focus on strengthening the safety, harvesting machinery and complete sets of processing equipment, key components, multi-purpose transport equipment, and automation, intelligent electronic control standards such as research and development.

Internal combustion engine field: focus on strengthening the electronic fuel injection system, alternative fuel engine and its key components, internal combustion engine emission control and post-processing systems, efficient turbocharged, internal combustion engine and key components reliability standards and research and development.

Electrician electrical field: focus on strengthening the efficient clean power generation equipment, new energy and renewable energy power generation equipment, energy storage technology and equipment, smart grid equipment, UHV transmission equipment and other standards of research and development.

Safety production areas: focus on strengthening electrical safety standards, various operating safety standards, safety equipment and technical standards of research and development.

Energy conservation areas: focus on strengthening the electrical system energy efficiency standards, industrial boiler furnace energy consumption standards, fuel consumption limits of internal combustion engine products and measurement methods standards, energy-saving mechanical and electrical products standards research and development.

Clean production areas: focus on strengthening the design and formulation of ecological design standards.

Comprehensive utilization of resources: focus on strengthening the mechanical and electrical products remanufacturing standards, resource recycling technology and equipment standards research and development.

In June 23, 2017, Taizhou City, Zhejiang province held the 2016 annual reduction unit Machinery Industry Standardization Technical Committee Annual Meeting and "steering" gear 3 standard manuscript review conference.

Main contents of the meeting

1、 higher leadership speech;

2、 Read out the reply of the China Federation of machinery industry on the members of the Technical Committee for regulating the standardization of mechanical transmission reduction machines, and issue members' certificates;

3、chairman of the speech;

4、 informed the machine together "2017 machinery industry standardization work points";

5、Summarize the work in 2016 and the work plan for 2017;

6、 the construction machinery industry in 13th Five-Year "technical standard system

7、3 criteria for peer review.