Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
This standard replaces NB/T 31018-2011 Wind turbine generator system technical specification of electric pitch system, in addition to a number of editorial changes, the following main technical changes have been made with respect to NB/T 31018-2011.
——The requirements of the use place are modified;
——The normal test environment requirements are modified as that the relative humidity shall be ≤90% below the environmental temperature of 20℃;
——The function of manually switching on and off the pitch has been modified, and the requirements are added that only one blade be allowed to be controlled at the same time and that the other blade be driven only after the controlled one returns to a safe position;
——The man-machine service operation function is modified; for the speed control and position control, the requirement is added that they be controlled only with the pitch control system in manual mode or maintenance mode;
——The requirement is modified as that maximum pitch rate of the three blades shall not be greater than the maximum design speed of the generator system
——The communication interface mode of the pitch system is modified;
——The requirement is modified as that the charge time of the capacitor-based backup power system from 0V to rated voltage should be less than 15min;
——The requirements for grid adaptability are modified;
——The requirement is modified as that in the type inspection items the loading property shall not be subject to end-of-manufacturing inspection;
——The fault of pitch controller (including pitch system with centralized controller) in fault diagnosis is modified;
——The requirement of cabinet body being made of stainless steel is canceled;
——The requirement of pitch acceleration control is canceled;
——The requirement is deleted that when the safe chain is disconnected, the safe chain of the pitch system include the following parts: emergency shutdown button, pitch controller fault (for pitch system including controller) and fault of any driver:
——The requirement of ride-through fault at grid voltage is added;
——The requirement is added that should the electromagnetic compatibility test standard be exceeded, it shall be negotiated with the customers.
This standard was proposed by China Electrical Equipment Industrial Association.
This standard is under the jurisdiction of Subcommittee on Wind Power Electrical Equipment of the National Technical Committee on Wind Power in Energy Industry of Standardization Administration of China
The previous edition of this standard is as follows:
——NB/T 31018-2011.
Technical specification for electric pitch system of wind turbine generator system
1 Scope
This standard specifies the technical requirements, test methods, inspection rules as well as marking, operation instructions, packaging, transport and storage of electric pitch control system of variable-speed constant-frequency wind turbine generator system.
This standard is applicable to the electric pitch control system of grid-connected onshore horizontal axis wind turbine generator system, serving as the basis for design, manufacturing, testing and certification.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 191 Packaging - Pictorial marking for handling of goods
GB 755-2008 Rotating electrical machines - Rating and performance
GB/T 2422 Environmental testing - Guide to drafting of test methods - Terms and definitions
GB/T 2423.1-2008 Environmental testing - Part 2: Test methods - Tests A: Cold
GB/T 2423.2-2008 Environmental testing - Part 2: Test methods - Tests B: Dry heat
GB/T 2423.3-2016 Environmental testing - Part 2: Testing method - Test Cab: Damp heat, steady state
GB/T 2423.4-2008 Environmental testing for electric and electronic products - Part 2: Test method - Test Db: Damp heat, cyclic (12h+12h cycle)
GB/T 2900.1 Electrotechnical terminology - Fundamental terms
GB/T 2900.53 Electro-technical terminology - Wind turbine generator systems
GB/T 2900.57 Electrotechnical terminology - Generation, transmission and distribution of electricity - Operation
GB/T 3797-2016 Electrical control assemblies
GB/T 3859.1-2013 Semiconductor converters - General requirements and line commutated converters - Part 1-1: Specification of basic requirements
GB/T 4208 Degrees of protection provided by enclosure (IP code)
GB/T 4365 Electrotechnical terminology - Electromagnetic compatibility
GB 5226.1-2008 Electrical safety of machinery - Electrical equipment of machines - Part 1: General requirements
GB/T 7251.1-2013 Low-voltage switchgear and controlgear assemblies - Part 1: General rules
GB/T 9969 General principles for preparation of instructions for use of industrial products
GB/T 11287-2000 Electrical relays - Part 21: Vibration, shock, bump and seismic tests on measuring relays and protection equipment - Section one: Vibration tests (sinusoidal)
GB/T 14537-1993 Shock and bump tests on measuring relays and protection equipment
GB/T 15543-2008 Power quality - Three-phase voltage unbalance
GB/T 15969.1 Programmable controllers - Part 1: General information
GB/T 15969.2 Programmable controllers - Part 2: Equipment requirements and tests
GB/T 17626.2-2018 Electromagnetic compatibility (EMC) - Testing and measurement techniques - Electrostatic discharge immunity test
GB/T 17626.3-2016 Electromagnetic compatibility - Testing and measurement techniques - Radiated radio-frequency electromagnetic field immunity test
GB/T 17626.4-2018 Electromagnetic compatibility - Testing and measurement techniques - Electrical fast transient/burst immunity test
GB/T 17626.5-2008 Electromagnetic compatibility - Testing and measurement techniques - Surge immunity test
GB/T 17626.6-2017 Electromagnetic compatibility - Testing and Measurement Techniques - Immunity to Conducted Disturbances Induced by Radio-frequency Fields
GB/T 18451.1-2012 Wind turbine generator systems - Design requirements
GB/T 19608.1 Classification of special environmental condition - Part 1: Dry heat
GB/T 19608.2 Classification of special environmental condition - Part 2:Dry heat-desert
GB/T 19608.3 Classification of special environmental condition - Part 3: Plateau
GB/T 19963 Technical rule for connecting wind farm to power system
GB/T 20641 Empty enclosures for low-voltage switchgear and controlgear assemblies - General requirements
GB/T 21714.4-2015 Protection against lightning - Part 4: Electrical and electronic systems within structures
GB/T 20540 Digital data communication for measurement and control - Fieldbus for use in industrial systems - Type 3: PROFIBUS specification - Part 6: Application layer protocol specification
ISO 11898 Road vehicles - Controller area network (CAN)
EN 175301-801 Detail Specification: High density rectangular connectors, round removable crimp contacts
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2422, GB/T 2900.1, GB/T 2900.53, GB/T 2900.57 and GB/T 4365 as well as the following ones apply.
3.1
supply disconnection
influential long-term interruption of power supply due to the disconnection of the switch
3.2
failure
termination of the implementation of certain specified function
Notes:
1 This concept of “failure” as definition does not apply to function items consisting of software only.
2 After failure the function item has a fault.
3 "Failure" is an event, as distinguished from "fault", which is a state.
3.3
safe-chain
hardware protection circuit constituted by several key protection nodes in series of a wind turbine generator, which is independent of control system
3.4
fault
state characterized by inability to perform a specified function, which does not include the states where the specified function cannot be implemented during preventative maintenance and other planned action, or for lack of external resources and which
is often the result of a failure of a function item itself, but may exist prior to failure
3.5
normal shutdown
shutdown with the whole process under the control of the control system
3.6
emergency shutdown
wind turbine generator system being made shutdown quickly due to triggering of the safe-chain
3.7
electric pitch control system
device for adjusting the blade angle which mainly comprises a pitch controller, a pitch motor, a pitch driver, a backup power supply and other components
3.8
pitch driver
device for adjusting the blade angle of wind turbine generator system by driving the pitch motor
3.9
backup power supply
power supply that provides energy support for the electric pitch control system when the power grid is powered down
3.10
feathering
geometric angle of attack of the wind turbine blades changing to a state where the sum of the wind turbine blades approaches zero lift, which is usually divided into normal feathering and emergency feathering
3.11
pitch angle
included angle between the blade chord line and the wind turbine blade rotating surface at the specified blade radial position
3.12
operating blade angle range
working range of the blade pitch angle corresponding to the normal operating range of the wind turbine generator system
3.13
the maximum pitch rate
maximum allowable pitch angle change rate
3.14
redundancy
technology of using two sets of devices or systems, with the objective of ensuring that in the event of failure of one set the other set is able to effectively perform the required function
3.15
blade
components that absorb wind energy to drive the wind wheel to rotate
4 Technical requirements
4.1 Service conditions
4.1.1 Normal operating environment conditions
It shall be suitable for the following conditions and can work normally:
a) working environment temperature.
1) normal temperature type: -20℃~+45℃.
2) low temperature type: -30℃~+45℃.
b) relative humidity.
The air shall be clean, the relative humidity shall not exceed 50% at a maximum temperature of +45 °C. At low temperatures, higher relative humidity is allowed. For example, the relative humidity is 95% at +20℃, considering that condensation may occur in case of temperature changes.
c) altitude ≤ 2,000m.
4.1.2 Normal test environment conditions
Operating climate conditions are mainly included, test shall be carried out under the following atmospheric environment:
a) environmental temperature: below 20℃.
b) relative humidity: ≤90%.
c) atmospheric pressure: 86kPa~106kPa.
4.1.3 Power supply conditions
4.1.3.1 AC power supply
a) Power frequency range: 47.5 Hz ~ 51.5 Hz.
b) Allowable fluctuation range of the power supply voltage: -10% to +10% of the voltage rating.
c) The unbalancedness of power supply shall meet the provisions of GB/T 15543-2008, Clause 4, and work normally within the scope.
d) The power supply waveform is sinusoidal wave with a total harmonic content of less than 5%.
4.1.3.2 DC power supply
a) The permissible deviation range of power supply voltage: -15%~+10%.
b) The power supply voltage ripple coefficient shall be less than 5%.
4.1.4 Requirements of the use place
a) In the environment, there shall be no corrosive gas or conductive medium that damages insulation, no medium that causes fire or explosion, and no obvious and serious mold.
b) The use place shall prevent the ingress of rain, snow and sand.
c) The grounding resistance of the use place shall be less than or equal to 4Ω.
d) The requirements for special use places are specified in GB/T 19608.1, GB/T 19608.2 and GB/T 19608.3.
4.1.5 Other service conditions
When the environmental conditions specified in 4.1.1~4.1.4 are exceeded, the manufacturer shall sign a special agreement with the user.
4.2 Structural requirements
4.2.1 Cabinet design requirements
a) The construction of cabinet shall comply with the provisions of GB 20641.
b) The enclosure, appearance and surface shall be free of scratch or deformation, and shall meet the provisions of 6.2.1 in GB/T 3797-2016.
c) Refer to GB 4208 for the description of protection level. The specific requirements are as follows:
1) The cabinet body protection level is IP 54.
2) The protection level of exposed connectors is IP 65.
3) The protection level of all external sensors and switches are IP 65.
If the user has special requirements, it shall be determined by the manufacturer and the user through negotiation.
4.2.2 Electrical connection requirements
They shall meet the requirements specified in GB 5226.1, Clause 13.
4.2.3 Components and parts requirements
Components and parts used in the system shall meet the requirements specified in the corresponding standards. Where,
a) The programmable controller shall meet the provisions of GB/T 15969.1 and GB/T 15969.2.
b) The wires and cables of the cabinet body shall meet the requirements of GB 5226.1, Clause 13.
c) The cabinet connector shall meet the requirements of EN 175301-801.
4.3 Functional requirements
4.3.1 Pitch function
4.3.1.1 Manual switch pitch function
The system shall have the function of manually switching on and off the pitch, and be capable of inching control on each blade separately. Only one blade is allowed to be controlled at the same time and the other blade can be driven only after the controlled one returns to a safe position.
4.3.1.2 Automatic pitch function
During normal operation, the pitch system shall be able to receive instructions from the control system of the wind turbine generator system, adjust the pitch angle in real time, reduce the load level borne by the generator system, and achieve the optimal and safe operation of the generator system. The pitch system shall be able to start automatically, change the pitch automatically and achieve feathering automatically according to the requirements of the main control, for example, it can control the pitch by issuing speed and pitch position instructions with the control system of the wind turbine generator system. The pitch system shall be able to work normally in the whole pitch control range, with the blades synchronous. The pitch performance shall meet the following technical requirements:
a) The maximum pitch rate of the three blades shall not be greater than the maximum design speed of the generator system.
b) The control precision of the pitch driver is not more than 0.05°.
c) The recommended value of the asynchrony of the three blades shall not be more than 1°.
d) In case of continuous pitch, the time from the time when the pitch system receives the pitch change instruction issued by the main control system to the time when the pitch bearing starts to act shall not be greater than 200 ms.
e) The pitch controller instruction scanning cycle shall not be more than 20 ms.
4.3.1.3 Man-machine service operation function
Information interaction: inquiry and setting of pitch control system parameters, system status check and fault diagnosis information check.
Speed control: where the pitch control system is in manual mode or maintenance mode, inching control may be carried out on the pitch direction and pitch rate of each blade through the man-machine interface.
Position control: where the pitch control system is in manual mode or maintenance mode, position control may be carried out on each blade through the man-machine interface. The blade pitch speed and given position may be set.
Calibration: the pitch control system has the function of calibrating the 0 position of the encoder or the position of the limit switch.
4.3.2 Safe feathering
4.3.2.1 Power failure of the system
In case of power failure of the system, the backup power supply of the pitch system shall be automatically switched on to complete safe feathering.
4.3.2.2 Communication fault
The pitch system shall be able to automatically complete safe feathering in case of any communication fault between the pitch system and the main control system.
4.3.2.3 Safe-chain disconnection
The safe-chain is divided into two parts: the safe-chain of the pitch system and that from the main control system to the pitch system. If the safe-chain is disconnected, the pitch system shall be able to automatically complete safe feathering.
4.3.3 Fault diagnosis
The pitch system shall have self-diagnosis and protection functions to detect the fault or abnormal conditions of the equipment in real time, and it shall be provided with a good security policy for processing. It shall have complete accident record information to facilitate fault diagnosis, and the information can be timely sent to the control system. The diagnosis and protection may cover the following aspects:
a) lightning protection action.
b) action of fuse or protection switch.
c) abnormal cabinet body temperature.
d) communication timeout or interruption.
e) pitch controller fault (for pitch system with centralized controller).
f) driver fault, which generally includes the following items:
1) low voltage of DC bus;
2) DC bus overvoltage;
3) overcurrent of the driver;
4) overtemperature of the driver;
5) power switch fault;
6) abnormal internal power supply;
7) braking resistor circuit fault;
8) phase loss of the motor:
9) short circuit, open circuit and numerical abnormality of speed and position sensor;
10) fault of internal fan.
g) motor fault, which shall generally include the following items:
1) overtemperature of the motor;
2) overcurrent of the motor;
3) motor stall protection;
4) abnormal braking of the motor.
h) charger fault.
i) open-circuit of charger circuit.
j) abnormal voltage of backup power supply, including overvoltage and undervoltage.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Technical requirements
5 Test methods
6 Test rules
7 Marking and operation instructions
8 Packaging, transport and storage
Annex A (Informative) Calculation of charge and discharge time of capacitor
NB/T 31018-2018, NB 31018-2018, NBT 31018-2018, NB/T31018-2018, NB/T 31018, NB/T31018, NB31018-2018, NB 31018, NB31018, NBT31018-2018, NBT 31018, NBT31018
Introduction of NB/T 31018-2018
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
This standard replaces NB/T 31018-2011 Wind turbine generator system technical specification of electric pitch system, in addition to a number of editorial changes, the following main technical changes have been made with respect to NB/T 31018-2011.
——The requirements of the use place are modified;
——The normal test environment requirements are modified as that the relative humidity shall be ≤90% below the environmental temperature of 20℃;
——The function of manually switching on and off the pitch has been modified, and the requirements are added that only one blade be allowed to be controlled at the same time and that the other blade be driven only after the controlled one returns to a safe position;
——The man-machine service operation function is modified; for the speed control and position control, the requirement is added that they be controlled only with the pitch control system in manual mode or maintenance mode;
——The requirement is modified as that maximum pitch rate of the three blades shall not be greater than the maximum design speed of the generator system
——The communication interface mode of the pitch system is modified;
——The requirement is modified as that the charge time of the capacitor-based backup power system from 0V to rated voltage should be less than 15min;
——The requirements for grid adaptability are modified;
——The requirement is modified as that in the type inspection items the loading property shall not be subject to end-of-manufacturing inspection;
——The fault of pitch controller (including pitch system with centralized controller) in fault diagnosis is modified;
——The requirement of cabinet body being made of stainless steel is canceled;
——The requirement of pitch acceleration control is canceled;
——The requirement is deleted that when the safe chain is disconnected, the safe chain of the pitch system include the following parts: emergency shutdown button, pitch controller fault (for pitch system including controller) and fault of any driver:
——The requirement of ride-through fault at grid voltage is added;
——The requirement is added that should the electromagnetic compatibility test standard be exceeded, it shall be negotiated with the customers.
This standard was proposed by China Electrical Equipment Industrial Association.
This standard is under the jurisdiction of Subcommittee on Wind Power Electrical Equipment of the National Technical Committee on Wind Power in Energy Industry of Standardization Administration of China
The previous edition of this standard is as follows:
——NB/T 31018-2011.
Technical specification for electric pitch system of wind turbine generator system
1 Scope
This standard specifies the technical requirements, test methods, inspection rules as well as marking, operation instructions, packaging, transport and storage of electric pitch control system of variable-speed constant-frequency wind turbine generator system.
This standard is applicable to the electric pitch control system of grid-connected onshore horizontal axis wind turbine generator system, serving as the basis for design, manufacturing, testing and certification.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 191 Packaging - Pictorial marking for handling of goods
GB 755-2008 Rotating electrical machines - Rating and performance
GB/T 2422 Environmental testing - Guide to drafting of test methods - Terms and definitions
GB/T 2423.1-2008 Environmental testing - Part 2: Test methods - Tests A: Cold
GB/T 2423.2-2008 Environmental testing - Part 2: Test methods - Tests B: Dry heat
GB/T 2423.3-2016 Environmental testing - Part 2: Testing method - Test Cab: Damp heat, steady state
GB/T 2423.4-2008 Environmental testing for electric and electronic products - Part 2: Test method - Test Db: Damp heat, cyclic (12h+12h cycle)
GB/T 2900.1 Electrotechnical terminology - Fundamental terms
GB/T 2900.53 Electro-technical terminology - Wind turbine generator systems
GB/T 2900.57 Electrotechnical terminology - Generation, transmission and distribution of electricity - Operation
GB/T 3797-2016 Electrical control assemblies
GB/T 3859.1-2013 Semiconductor converters - General requirements and line commutated converters - Part 1-1: Specification of basic requirements
GB/T 4208 Degrees of protection provided by enclosure (IP code)
GB/T 4365 Electrotechnical terminology - Electromagnetic compatibility
GB 5226.1-2008 Electrical safety of machinery - Electrical equipment of machines - Part 1: General requirements
GB/T 7251.1-2013 Low-voltage switchgear and controlgear assemblies - Part 1: General rules
GB/T 9969 General principles for preparation of instructions for use of industrial products
GB/T 11287-2000 Electrical relays - Part 21: Vibration, shock, bump and seismic tests on measuring relays and protection equipment - Section one: Vibration tests (sinusoidal)
GB/T 14537-1993 Shock and bump tests on measuring relays and protection equipment
GB/T 15543-2008 Power quality - Three-phase voltage unbalance
GB/T 15969.1 Programmable controllers - Part 1: General information
GB/T 15969.2 Programmable controllers - Part 2: Equipment requirements and tests
GB/T 17626.2-2018 Electromagnetic compatibility (EMC) - Testing and measurement techniques - Electrostatic discharge immunity test
GB/T 17626.3-2016 Electromagnetic compatibility - Testing and measurement techniques - Radiated radio-frequency electromagnetic field immunity test
GB/T 17626.4-2018 Electromagnetic compatibility - Testing and measurement techniques - Electrical fast transient/burst immunity test
GB/T 17626.5-2008 Electromagnetic compatibility - Testing and measurement techniques - Surge immunity test
GB/T 17626.6-2017 Electromagnetic compatibility - Testing and Measurement Techniques - Immunity to Conducted Disturbances Induced by Radio-frequency Fields
GB/T 18451.1-2012 Wind turbine generator systems - Design requirements
GB/T 19608.1 Classification of special environmental condition - Part 1: Dry heat
GB/T 19608.2 Classification of special environmental condition - Part 2:Dry heat-desert
GB/T 19608.3 Classification of special environmental condition - Part 3: Plateau
GB/T 19963 Technical rule for connecting wind farm to power system
GB/T 20641 Empty enclosures for low-voltage switchgear and controlgear assemblies - General requirements
GB/T 21714.4-2015 Protection against lightning - Part 4: Electrical and electronic systems within structures
GB/T 20540 Digital data communication for measurement and control - Fieldbus for use in industrial systems - Type 3: PROFIBUS specification - Part 6: Application layer protocol specification
ISO 11898 Road vehicles - Controller area network (CAN)
EN 175301-801 Detail Specification: High density rectangular connectors, round removable crimp contacts
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2422, GB/T 2900.1, GB/T 2900.53, GB/T 2900.57 and GB/T 4365 as well as the following ones apply.
3.1
supply disconnection
influential long-term interruption of power supply due to the disconnection of the switch
3.2
failure
termination of the implementation of certain specified function
Notes:
1 This concept of “failure” as definition does not apply to function items consisting of software only.
2 After failure the function item has a fault.
3 "Failure" is an event, as distinguished from "fault", which is a state.
3.3
safe-chain
hardware protection circuit constituted by several key protection nodes in series of a wind turbine generator, which is independent of control system
3.4
fault
state characterized by inability to perform a specified function, which does not include the states where the specified function cannot be implemented during preventative maintenance and other planned action, or for lack of external resources and which
is often the result of a failure of a function item itself, but may exist prior to failure
3.5
normal shutdown
shutdown with the whole process under the control of the control system
3.6
emergency shutdown
wind turbine generator system being made shutdown quickly due to triggering of the safe-chain
3.7
electric pitch control system
device for adjusting the blade angle which mainly comprises a pitch controller, a pitch motor, a pitch driver, a backup power supply and other components
3.8
pitch driver
device for adjusting the blade angle of wind turbine generator system by driving the pitch motor
3.9
backup power supply
power supply that provides energy support for the electric pitch control system when the power grid is powered down
3.10
feathering
geometric angle of attack of the wind turbine blades changing to a state where the sum of the wind turbine blades approaches zero lift, which is usually divided into normal feathering and emergency feathering
3.11
pitch angle
included angle between the blade chord line and the wind turbine blade rotating surface at the specified blade radial position
3.12
operating blade angle range
working range of the blade pitch angle corresponding to the normal operating range of the wind turbine generator system
3.13
the maximum pitch rate
maximum allowable pitch angle change rate
3.14
redundancy
technology of using two sets of devices or systems, with the objective of ensuring that in the event of failure of one set the other set is able to effectively perform the required function
3.15
blade
components that absorb wind energy to drive the wind wheel to rotate
4 Technical requirements
4.1 Service conditions
4.1.1 Normal operating environment conditions
It shall be suitable for the following conditions and can work normally:
a) working environment temperature.
1) normal temperature type: -20℃~+45℃.
2) low temperature type: -30℃~+45℃.
b) relative humidity.
The air shall be clean, the relative humidity shall not exceed 50% at a maximum temperature of +45 °C. At low temperatures, higher relative humidity is allowed. For example, the relative humidity is 95% at +20℃, considering that condensation may occur in case of temperature changes.
c) altitude ≤ 2,000m.
4.1.2 Normal test environment conditions
Operating climate conditions are mainly included, test shall be carried out under the following atmospheric environment:
a) environmental temperature: below 20℃.
b) relative humidity: ≤90%.
c) atmospheric pressure: 86kPa~106kPa.
4.1.3 Power supply conditions
4.1.3.1 AC power supply
a) Power frequency range: 47.5 Hz ~ 51.5 Hz.
b) Allowable fluctuation range of the power supply voltage: -10% to +10% of the voltage rating.
c) The unbalancedness of power supply shall meet the provisions of GB/T 15543-2008, Clause 4, and work normally within the scope.
d) The power supply waveform is sinusoidal wave with a total harmonic content of less than 5%.
4.1.3.2 DC power supply
a) The permissible deviation range of power supply voltage: -15%~+10%.
b) The power supply voltage ripple coefficient shall be less than 5%.
4.1.4 Requirements of the use place
a) In the environment, there shall be no corrosive gas or conductive medium that damages insulation, no medium that causes fire or explosion, and no obvious and serious mold.
b) The use place shall prevent the ingress of rain, snow and sand.
c) The grounding resistance of the use place shall be less than or equal to 4Ω.
d) The requirements for special use places are specified in GB/T 19608.1, GB/T 19608.2 and GB/T 19608.3.
4.1.5 Other service conditions
When the environmental conditions specified in 4.1.1~4.1.4 are exceeded, the manufacturer shall sign a special agreement with the user.
4.2 Structural requirements
4.2.1 Cabinet design requirements
a) The construction of cabinet shall comply with the provisions of GB 20641.
b) The enclosure, appearance and surface shall be free of scratch or deformation, and shall meet the provisions of 6.2.1 in GB/T 3797-2016.
c) Refer to GB 4208 for the description of protection level. The specific requirements are as follows:
1) The cabinet body protection level is IP 54.
2) The protection level of exposed connectors is IP 65.
3) The protection level of all external sensors and switches are IP 65.
If the user has special requirements, it shall be determined by the manufacturer and the user through negotiation.
4.2.2 Electrical connection requirements
They shall meet the requirements specified in GB 5226.1, Clause 13.
4.2.3 Components and parts requirements
Components and parts used in the system shall meet the requirements specified in the corresponding standards. Where,
a) The programmable controller shall meet the provisions of GB/T 15969.1 and GB/T 15969.2.
b) The wires and cables of the cabinet body shall meet the requirements of GB 5226.1, Clause 13.
c) The cabinet connector shall meet the requirements of EN 175301-801.
4.3 Functional requirements
4.3.1 Pitch function
4.3.1.1 Manual switch pitch function
The system shall have the function of manually switching on and off the pitch, and be capable of inching control on each blade separately. Only one blade is allowed to be controlled at the same time and the other blade can be driven only after the controlled one returns to a safe position.
4.3.1.2 Automatic pitch function
During normal operation, the pitch system shall be able to receive instructions from the control system of the wind turbine generator system, adjust the pitch angle in real time, reduce the load level borne by the generator system, and achieve the optimal and safe operation of the generator system. The pitch system shall be able to start automatically, change the pitch automatically and achieve feathering automatically according to the requirements of the main control, for example, it can control the pitch by issuing speed and pitch position instructions with the control system of the wind turbine generator system. The pitch system shall be able to work normally in the whole pitch control range, with the blades synchronous. The pitch performance shall meet the following technical requirements:
a) The maximum pitch rate of the three blades shall not be greater than the maximum design speed of the generator system.
b) The control precision of the pitch driver is not more than 0.05°.
c) The recommended value of the asynchrony of the three blades shall not be more than 1°.
d) In case of continuous pitch, the time from the time when the pitch system receives the pitch change instruction issued by the main control system to the time when the pitch bearing starts to act shall not be greater than 200 ms.
e) The pitch controller instruction scanning cycle shall not be more than 20 ms.
4.3.1.3 Man-machine service operation function
Information interaction: inquiry and setting of pitch control system parameters, system status check and fault diagnosis information check.
Speed control: where the pitch control system is in manual mode or maintenance mode, inching control may be carried out on the pitch direction and pitch rate of each blade through the man-machine interface.
Position control: where the pitch control system is in manual mode or maintenance mode, position control may be carried out on each blade through the man-machine interface. The blade pitch speed and given position may be set.
Calibration: the pitch control system has the function of calibrating the 0 position of the encoder or the position of the limit switch.
4.3.2 Safe feathering
4.3.2.1 Power failure of the system
In case of power failure of the system, the backup power supply of the pitch system shall be automatically switched on to complete safe feathering.
4.3.2.2 Communication fault
The pitch system shall be able to automatically complete safe feathering in case of any communication fault between the pitch system and the main control system.
4.3.2.3 Safe-chain disconnection
The safe-chain is divided into two parts: the safe-chain of the pitch system and that from the main control system to the pitch system. If the safe-chain is disconnected, the pitch system shall be able to automatically complete safe feathering.
4.3.3 Fault diagnosis
The pitch system shall have self-diagnosis and protection functions to detect the fault or abnormal conditions of the equipment in real time, and it shall be provided with a good security policy for processing. It shall have complete accident record information to facilitate fault diagnosis, and the information can be timely sent to the control system. The diagnosis and protection may cover the following aspects:
a) lightning protection action.
b) action of fuse or protection switch.
c) abnormal cabinet body temperature.
d) communication timeout or interruption.
e) pitch controller fault (for pitch system with centralized controller).
f) driver fault, which generally includes the following items:
1) low voltage of DC bus;
2) DC bus overvoltage;
3) overcurrent of the driver;
4) overtemperature of the driver;
5) power switch fault;
6) abnormal internal power supply;
7) braking resistor circuit fault;
8) phase loss of the motor:
9) short circuit, open circuit and numerical abnormality of speed and position sensor;
10) fault of internal fan.
g) motor fault, which shall generally include the following items:
1) overtemperature of the motor;
2) overcurrent of the motor;
3) motor stall protection;
4) abnormal braking of the motor.
h) charger fault.
i) open-circuit of charger circuit.
j) abnormal voltage of backup power supply, including overvoltage and undervoltage.
Contents of NB/T 31018-2018
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Technical requirements
5 Test methods
6 Test rules
7 Marking and operation instructions
8 Packaging, transport and storage
Annex A (Informative) Calculation of charge and discharge time of capacitor
