This standard is the safety requirements for small wind turbine generator sets (SWTGS). It involves safety principles, quality assurance, engineering integrity and specific requirements, including design, installation, maintenance and operation under specific external conditions. Its purpose is to establish an appropriate level of protection to prevent accidents and damage to the unit during its planned life. This standard also involves various auxiliary systems of the unit, such as protection mechanisms, internal electrical systems, mechanical systems, support structures, foundations and electrical connections to loads. This standard applies to units with a swept area of ​​less than 40m2 and a voltage of less than 1000V (ac) or 1500V (dc). GB 17646-1998 Safety requirements for small wind turbine generator sets GB17646-1998 Standard download decompression password: www.bzxz.net

GB17646--1998bzxz.net
This standard is equivalent to IEC1400-2:1996 "Safety Requirements for Small Wind Turbine Generators". In order to make the small wind turbine generators produced in my country adapt to the needs of international trade, technology and exchanges as soon as possible, it is very necessary to fully adopt the safety requirements in the IEC standard. However, considering the actual situation that a large number of small wind turbine generators are used in northern my country, the ambient temperature is far lower than the normal temperature and extreme temperature requirements specified in the IEC standard. Therefore, in combination with the specific conditions of my country's environmental conditions, the standard in Chapter 3 will reduce the normal operating temperature range of the system for units used in high-cold areas and the temperature range for operation under extreme conditions by 5°C, increase the reference extreme wind speed by 5m/s, and take appropriate consideration of the environmental conditions containing sand and dust in the atmosphere. For other regions, it is still consistent with the international standard. In this way, the standard-level units for export still fully meet the requirements of the international standard. When the international standard IEC1400-2 is converted into a national standard, the chapters and article numbers are not changed. It is convenient for comparison and use. Appendix A of this standard is a prompt appendix.
This standard is proposed by the Ministry of Machinery Industry.
This standard is under the jurisdiction of the National Technical Committee for Standardization of Wind Power Machinery. The drafting unit of this standard is the Hohhot Animal Husbandry Machinery Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Shu Zhaoming and Song Jingxuan. 202
GB17646-1998
IEC Foreword
1) IEC (International Electrotechnical Commission) is a worldwide standardization organization composed of national electrotechnical committees (IEC National Committees). The goal of IEC is to promote international cooperation in standardization in the electrical and electrical fields. To achieve this goal and carry out other activities, IEC publishes international standards and entrusts technical committees to draft international standards; any IEC National Standards Committee interested in the project involved can participate in the drafting of the project, and international, governmental and non-governmental organizations that have established liaison relations with IEC can also participate in the drafting work. IEC and the International Organization for Standardization (ISO) work closely in accordance with the agreement established between the two organizations. 2) The formal resolutions or agreements formed by the IEC on technical aspects express the most consistent international opinions on the relevant items, because each technical committee is composed of representatives from the relevant national committees. 3) The resulting documents have the form of recommendations for international use and are published in the form of standards, technical reports or guidelines, and are accepted by the national committees.
4) In order to promote international unification, each IEC national committee should clearly and to the greatest extent possible adopt IEC international standards in its national and regional standards, and any differences between IEC standards and corresponding national or regional standards should be clearly pointed out in the latter. 5) IEC does not provide instructions for its approval process. It is not responsible for the requirement that any equipment must comply with one of its standards.
6) It should be noted that some units of this international standard may have patent rights, and IEC is not responsible for identifying any or all of these patent rights. International Standard IEC1400-2 has been drafted by IEC Technical Committee 88 (Technical Committee for Wind Power Equipment). The text of this standard is based on the following documents: FDIS
88/53/FDIS
Voting Report
88/65/RVD
The full details of the balloting for this standard can be found in the balloting report mentioned in the table above. Appendix A is for information only. 203
GB 17646—1998
This standard sets out the minimum safety requirements for small wind turbine generator systems and is not intended to be used as a complete design specification or structural specification. Compliance with this standard does not imply that any individual, organization or company is exempt from complying with other applicable specifications. 204
1 Overview
National Standard of the People's Republic of China
Safety requirements for small wind turbine generator systems
Safety of small wind turbine generator systems 1.1 Subject and scope
GB17646 - 1998
eqv IEC 1400-2: 1996
This standard sets out the safety requirements for small wind turbine generator systems (SWTGS) (hereinafter referred to as the unit). It covers safety principles, quality assurance, engineering integrity and specific requirements, including design, installation, maintenance and operation under specific external conditions. Its purpose is to establish an appropriate level of protection to prevent accidents and damage to the unit during its planned life cycle. This standard also covers the auxiliary systems of the unit, such as protection mechanisms, internal electrical systems, mechanical systems, support structures, foundations and electrical connections to the load. This standard applies to units with a swept area of ​​less than 40m2 and a voltage lower than 1000V (a·c.) or 1500V (dc.). This standard should be used in conjunction with relevant national standards, IEC and ISO standards (see 1.2). 1.2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of this standard, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T19001-1994 Quality system - Quality assurance model for design, development, production, installation and service (idt ISO 9001: 1994)
GB/T19002:1994 Quality system - Quality assurance model for production, installation and service (idtISO9002:1994)GB/T19003:1994 Quality system - Quality assurance model for final inspection and testing (idtISO9003:1994)IEC364 Electrical installation of buildings
IEC529:1989 Degrees of protection of enclosures (IP rule)IEC1000 Electromagnetic compatibility (EMC)
IEC1400-1:1994 Wind power generation equipment - Part 1: Safety requirementsIEC CISPR 11:1990 Industrial, scientific and medical (ISM) radio frequency equipment - Methods of measurement and limits of electromagnetic disturbance characteristics ISO2394:1986 General principles for structural reliability
Supplement 1 (1988)
1.3 Definitions
This standard adopts the following definitions.
1.3.1 Braking
A means that can effectively reduce the speed of the wind rotor or stop it from rotating. 1.3.2 Control system
An auxiliary device that receives signals from the status of the wind turbine and its operating environment and adjusts the wind turbine to keep it operating within a limited range. 1.3.3 Cut-in wind speed (vin)
The minimum wind speed at the hub height when the wind turbine starts to output useful power. 1.3.4 Cut-out wind speed (Vout)
The maximum wind speed at the hub height when the wind turbine outputs useful power as specified in the design. Approved by the State Administration of Quality and Technical Supervision on December 21, 1998, and implemented on October 1, 1999
1.3.5 Design limit
The maximum or minimum value used in the design.
1.3.6 Design condition
GB 17646 --1998
The possible operating mode of the unit (such as power generation, parking, etc.). 1.3.7 External condition
The factors affecting the operation of the wind turbine, including wind conditions and other meteorological factors (snow, ice, etc.). 1.3.8 Fail-safe
One of the design characteristics, that is, the safety of the equipment can be maintained in the event of an emergency failure. 1.3.9 Gust
The instantaneous change in wind speed. Its characteristics can be expressed by its formation time, strength and duration. 1.3.10 Horizontal axis wind turbine (HAWT)
A wind turbine with the rotor axis basically parallel to the wind direction. 1.3.11 Hub
The device that can mount the blades or blade assemblies on the rotor shaft. 1.3.12 Hub height
The height of the rotor center from the ground. The hub height of the vertical axis is the height of the swept surface center from the ground. 1.3.13 Snap
The state of the wind turbine running slowly without power output. 1.3.14 Limit state
A state in which the load acts on the structure. If this range is exceeded, the structure no longer meets the design requirements (see ISO2394). Note: The purpose of the design calculation (design requirements for limit states) is to determine the possibility of keeping the limit state within a certain specified value range, which is determined by the type of structure (see ISO2394).
1.3.15 Load case
The structural load resulting from the combined consideration of the design conditions and external conditions. 1.3.16 Average wind speed
The average statistical value of the instantaneous wind speed over a given period of time, which can range from a few seconds to many years. 1.3.17 Nacelle
The casing containing the transmission and other devices located at the top of the tower of a horizontal axis wind turbine. 1.3.18 Shutdown
The reset state of a wind turbine after normal shutdown. 1.3.19 Output power
The power output by a device in a special way to achieve a specific purpose. Note: The electrical power output by a wind turbine generator set. 1.3.20 Protection system
Safety protection device that keeps the unit within the design limit. 1.3.21 Rated power
The power that a component, device or equipment can achieve under specified operating conditions, usually given by the manufacturer. Note: The maximum continuous electrical output that the unit is designed to achieve under normal operating conditions. 1.3.22 Rated wind speed (VR)
The specific wind speed at which the wind turbine reaches rated power. 1.3.23 Reference extreme wind speed (vexr)
The maximum average wind speed at the hub height for 10 minutes that occurs once in 50 years. 1.3.24 Rotor speed
The speed at which the wind turbine rotor rotates around its axis. 1.3.25 Safety life
GB 17646 --1998
The expected service life, and the probability of serious failure should be indicated. 1.3.26 Shutdown
The process of the wind turbine changing between power generation and shutdown or idling. 1.3.27 Support structure
The tower and foundation of the wind turbine.
1.3.28 Swept area (for horizontal axis wind turbines) The projected area of ​​the circle made by the rotating motion of the rotor blade tip on the plane perpendicular to the wind speed vector. 1.3.29 End flow intensity
The ratio of the standard deviation of wind speed to the average wind speed, the average wind speed being determined from the wind speed sampling data measured in the same group during a given time period.
1.3.30 Wind shear
The variation of wind speed with height in a plane perpendicular to the wind direction. 1.3.31 Wind speed
The wind speed at a specific point in space, the instantaneous speed of air moving around that point. 1.3.32 Wind turbine
A device that converts wind energy into electrical energy.
1.3.33 Direction (for horizontal axis wind turbines) The rotation of the rotor shaft around the vertical axis.
1.4 Symbols and units
A Cross-sectional area
Aproi Projected area on the plane perpendicular to the wind directionB Number of blades
Ca Drag coefficient
Distance between rotor and tower center
Distance from rotor center of gravity to rotor axis of rotationF Force
FtB, FyB, FB Force acting on blade rootFx-, Fy- and Fz-Force acting on rotor connection point on rotor axisg Acceleration of gravity
h Height of rotor axis from ground
IB Moment of inertia of blade
lrb Distance between rotor center of gravity and front bearing
M Brake Nominal torque of mechanical brake
M, M, MB Torque acting on blade root Torque on the front bearing of the wind rotor
Mx-axis
Bending moment acting on the front bearing of the wind rotor
MB-axis
Blade mass
Rotor mass
Nacelle mass
Rotor speed
[m·s-?]
[kg·m”]
[N·m]
[N·m]
[N·m]
[r·min-}]
Maximum speed of wind rotor
Rotor speed at rated wind speed
Rated power of small wind turbine generator set
Rotor shaft torque at rated wind speed
RRotor radius
GB 17646 -1998
Distance between the center of gravity of the blade and the connection point between the blade root and the hubRehar
Material strength
Cut-in wind speed
Cut-out wind speed
Wind speed at hub height
Rated wind speed
Reference extreme wind speed
Section coefficient
Safety factor
Tip speed ratio at rated wind speed
Air density
Design strength (calculated by design load)
Equivalent strength
Shear strength
Angular velocity
Use a coordinate system to define the load direction, as shown in Figure 1. Adopt Note:
1] was originally sl, which should be changed to rad·s\1.208
[r·min-]
[r·min-
[N·m]
EN·m-2]
Em·s-]
[m·si]
[m·s-1]
[m·s--]
[m·s-\]
[kg·m-3]
[N·m-2]
[N·m\?]
[N?m-?]
[N·m-?]
[rad·s- 1
Note: The blade coordinate system rotates with the wind rotor.
The wind rotor axis coordinate system rotates with the cabin.
The tower coordinate system is fixed.
Abbreviations
Small wind turbine
HAWT horizontal axis wind turbine
2 Basic elements
2.1 Overview
GB17646—1998
Y blade
Figure 1 Definition of coordinate system for horizontal axis wind turbine
Engineering integrity includes structural design, mechanical, electrical and control systems, which should be achieved by the requirements of this standard for design, manufacturing and quality management.
The installation, operation and maintenance of the unit apply modern integrated technology, and the safety procedures established in these technical fields must be implemented. 2.2 Quality assurance
Quality assurance should be an integral part of the design, improvement and manufacturing of the unit and all its components, and an integral part of the assembly, installation, operation and maintenance documents.
It is recommended that the quality assurance system should meet the requirements of GB/T19001, GB/T19002 and GB/T19003. 209
3 External conditions
GB17646---1998
The design of the unit should take into account the external conditions described in this chapter, which depend on the intended site and site type of the unit. Two wind turbine grades are specified; standard grade and special grade. The standard grade is designed to meet most applications and its parameters can represent the characteristic values ​​of many different sites. Special grade wind turbines should be used where specific design conditions are required. The parameter values ​​of the external conditions of the special grade should be specified and explained by the designer.
The standard level should consider the following external conditions:
--The reference extreme wind speed Vexr at the hub height is 35m·s-1, and the high-cold areas in my country are 40m·s-1;--The temperature range for normal operation of the system is -10℃ to +40℃, and the high-cold areas in my country are -15℃ to +35℃;--The temperature range for the system to operate under extreme conditions is -20℃ to +50℃, and the high-cold areas in my country are -25℃ to +45℃;--Relative humidity is 95%;||t t||Equivalent to unpolluted inland atmosphere, the environmental conditions containing sand and dust in the atmosphere should be appropriately considered for units used in high-altitude and cold regions of my country;
Air density at sea level p==1225kg·m-3.4 Structural design
4.1 Overview
The structural design of the unit should be carried out on the basis of verifying the structural integrity of the load-bearing components. The ultimate and fatigue strength of its structural components should be verified by test or calculation to verify that its structural safety has appropriate safety indicators. The structural design should comply with the relevant provisions of ISO2394. The acceptable safety index should be verified by calculation or test to verify that its design load does not exceed the corresponding design resistance. 4.2 Design method
The engineering integrity should be verified by calculation and (or) test, and the selection of test conditions, including the test load, should consider appropriate safety indicators.
Appropriate design methods should be used for calculation, and the load index of any review test should consider the safety index consistent with the calculation verification.
The design of the unit should be based on the combination of the design value of the external conditions and the design conditions related to the unit. The design conditions are derived from the load conditions. Considering the integrity of the project, all relevant load conditions should be analyzed. It should be ensured that the limit state does not exceed the design value of the wind turbine. The limit and fatigue limit state require the following issues to be considered: - Structural balance, or the balance destruction of any component of the unit considered as a rigid body. - Failure caused by excessive deformation, fracture (including fracture caused by increased fatigue) or damage to the stability of the structure and any of its components, including the supporting structure.
4.3 Loads
The following types of loads shall be considered in the design:
Aerodynamic loads
Aerodynamic loads are static and dynamic loads caused by the interaction of airflow on the stationary and moving parts of the unit. The airflow depends on the rotation speed of the wind rotor, the average wind speed through the plane of rotation of the wind rotor, the flow, air density, aerodynamic shape and their interaction, including the influence of aeroelasticity.
Inertial and gravity loads
Static and dynamic loads caused by inertial forces and gravity loads acting on the unit due to vibration, rotation and gravity. The corresponding dynamic excitation and various vibration mode couplings shall be considered in the load calculation. 4.4 Load conditions
This clause describes the definition of the design load conditions of the unit and specifies the minimum values ​​of the load conditions to be considered. 210
GB 17646-1998
For design purposes, the life of the unit is divided into a series of design conditions, which represent the most important working conditions that the unit may be subjected to. In this standard, these design conditions are determined by the various operating modes of the unit. The load conditions should be determined in combination with specific design conditions and external conditions. All relevant load conditions for various types of units and reasonable probability of occurrence must be considered, and the performance of the control and protection systems should also be considered. Generally, the design load conditions used to determine the structural integrity of the unit should be specified in combination with normal design conditions and normal and extreme external conditions. The load conditions of the unit in the case of failure should be determined based on a reasonable probability of occurrence in combination with the design conditions of failure and the corresponding external conditions.
Clause 4.5 introduces an example of a simplified load calculation process. This method is only valid for horizontal axis wind turbines with rigid hubs and cantilever blades. In order to reduce the amount of calculation and simplify the calculation, only the limit values ​​of the load conditions are considered in this calculation process. If this method is used, the dynamic effects should be considered in the conservative calculation. In addition, the determination of load conditions and load calculations can be carried out according to IEC1400-1. This calculation is only used for small units. The load conditions considered to simplify the calculation are listed in Table 1. Table 1 Design load conditions for simplified load calculation method Design condition
Load condition
Normal operation
Cyclic wind load
Loss of electrical load
Normal shutdown
Minimum wind exposure
Maximum wind exposure
Cyclic
Vhub=UR
Uhub= Vexr
Vhub= VR
Vhub=1. 4Vexr
Vhub = Vexr
Analysis type
Extreme load
Extreme load
Extreme load
Extreme load
The power alternates between 1.5Pr and 0.5Pr in a cyclic manner. The rotor speed varies alternately between 1.5nR and 0.5nR
Maximum possible turning speed
Measured speed at normal wind speed Extrapolated to exr braking torque
Normal parking position
Maximum angle of attack range
If a special class of unit design is required, other design load cases related to safety should be considered. 4.5 Simplified load calculation
The calculation method for the load cases listed in Table 1 is described as follows. 4.5.1 Power generation
The following three load cases are considered.
4.5.1.1 Normal operation (load case A) The load case for normal operation is assumed to be a fatigue load. Determine the forces and moments at the blade root, assuming that: the aerodynamic force acts at 2/3R on the Z axis of the blade; the output power varies periodically between 1.5P and 0.5PR, PR is the rated power; the rotor speed varies periodically between 1.5nR and 0.5nR. The fatigue range is set to full amplitude.
The tip speed ratio (at rated wind speed) and the rotor torque QR (at rated wind speed) are determined by formula (1): AR
RnR yuan
WR × 30
PR×30
nR yuann
Adoption instructions:
17 The original text is 9.5PR, which should be changed to 0.5PR (1)
GB176461998
In the formula, if the efficiency n is not given, 0.8 can be used. Load at blade root
Centrifugal force at blade root is determined by formula (2)
FrB = 2mgRegB
Bending moment at blade root is determined by formula (3)
AMrB =
?+ 2mggRegB
AMyB = AR
Load on wind rotor shaft
The magnitude of thrust on wind rotor shaft is determined by formula (4)AFx-
The magnitude of torque and bending moment on wind rotor shaft is determined by formula (5)AMx-axis = QR
AMy-axis = 2miglrh +
：（3）
（4）
（5）
4.5.1.2 Steering (Load Case B)
For the steering load case, the extreme loads (gyroscopic forces and moments) should be assumed to occur at the maximum steering angular velocity mx. The design value should be used for the maximum steering angular velocity mx, and the measured maximum steering angular velocity value should be used as much as possible. If the design value or measured value of max is not available, the maximum angular velocity should be set to wmax=1 rad·s-1 in the design, and the calculation is simplified by setting it as a rigid hub. The load at the blade root
The maximum bending moment during steering is determined by formula (6): AnR
MyE,max = mgwmaxeRegB -+ 2wmxI b30
Other forces and moments are small and can be assumed to be 0. Load on the rotor shaft
For a two-blade wind turbine, the bending moment of the rotor shaft adjustment is determined by formula (7):Mg-phase,max = 2BwmaxIg
+ mrglb -
RAFx一axis
（6）
For three-blade and multi-blade wind turbines, the bending moment of the rotor shaft adjustment is determined by formula (8):nr
Mg-axis,max BumaxI g
+mrglrb +
When adjusting, other forces and moments are very small or not in the same phase, so they can be assumed to be 0. (7
·（8)
4.5.1.3 Loss of electrical load (Load case C) When the electrical load is lost, the maximum possible operating rotor speed nmax should be measured or calculated at normal wind speed and linearly derived to Vexr. If the rotor speed is limited by the action of the control and protection system, this should be taken into account in the deduction. Load at the blade root
The centrifugal force load at the blade root is determined by formula (9): Fas.mx = mpRe(\0)
/ yuan nma
Load on the rotor shaft
The rotor shaft moment caused by the unbalance of the rotor at the maximum speed is determined by formula (10): 212
（9）
Where: e.=0.001R
4.5.2 Shutdown (Load Condition D)
MB-axis,max
GB 17646 -1998
（10）
When a braking device (mechanical brake, electrical brake) is provided in the wind turbine transmission system, its braking torque should be greater than the maximum driving torque. Therefore, the braking torque M of the unit should be designed and calculated. Load at the blade root
When the machine is shut down, the bending moment at the leading edge of the blade root is determined by formula (11): Mx-axis.m + mgReg
Load on the rotor shaft
When shutting down, the maximum torque on the shaft is calculated by formula (12): Mx1 turn,max = Mmove+Q
In formula (12), it is assumed that braking occurs when the generator is connected to the load. 4.5.3 Shutdown
Consider the following two load conditions.
（11）
4.5.3.1 Normal shutdown of the unit (load condition E) In this load condition, the wind turbine is shut down in a normal favorable manner, most of which are under the minimum wind effect. When calculating, the load on the wind-exposed part of the unit should be assumed to be 1.4 times the gust factor with reference to the extreme wind speed. Load acting on each component:
Where: Ca-
Thrust coefficient (see Figure 2);
P(1· 4Vexr)?Aproi
Aproi—projected area of ​​the component on the plane perpendicular to the wind direction. (13)
4.5.3.2 Shutdown + failure (load condition F) When the steering mechanism is in failure, the unit will be under the action of wind from any direction. Therefore, when designing, the calculation of this load condition should adopt the windward area under the most unfavorable steering angle. When in the shutdown state under extreme wind speed, the force on the unit components should be determined according to formula (14):
Load acting on each component
pUexr? Aproi
Where: Ca-
Thrust coefficient (see Figure 2);
Projected area of ​​the component on the plane perpendicular to the wind direction (when in the most unfavorable position). D or [<0.1m
D or 1>0.1m
Figure 2 Thrust coefficient Ca
..........( 14 )
4.6 Stress calculation
The multiple stresses calculated from the individual forces and moments under various load conditions must be combined to find their equivalent stress. The combined equivalent stress must be compared with the allowable stress of the material (see 4.7). 213
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.