NB/T 31004-2011Guidelines for vibration condition monitoring and diagnosis of wind turbine generator (English PDF)

3.1 Breakdown maintenance

Maintenance after wind turbine failure.

3.2 Condition-based maintenance

Maintenance determined according to wind turbine condition.

3.3 Condition monitoring

Detected and gathered information and data that reflect wind turbine condition.

3.4 Diagnostics

Symptom and syndrome inspections for determination of nature (type, condition, degree) of the fault or failure.

3.5 Failure

The ability of failing to perform certain specified function.

3.6 Fault

The condition of parts when a part or a module of wind turbine degrades, or anomalous condition occurs, which may cause wind turbine failure.

3.7 Alarm

The operating signal or message designed for informing staff when selected parameter or its logical combination is abnormal.

3.8 Alert

The operating signal or message designed for informing staff when selected parameter or its logical combination is abnormal and requires more attention.

3.9 Sign

Characteristic parameters of signal that indicate the condition of relative information.

3.10 Vibration signal

Measurement of all frequency components that are contained in a system vibration.

3.11 Frequency domain

Physical quantity that takes frequency as measurement.

3.12 Time domain

Physical quantity that takes time as measurement.

3.13 Cross-channel analysis

Using two or more analyzers of input channel to realize functions such as phase, relevance and transfer function calculation.

3.14 Baseline

Single or a group of descriptors that provides baseline for wind turbine's normal condition in various processes.

3.15 Waterfall

Three-dimensional multi-spectral display of relative time or speed.

4.1 Types of vibration condition monitoring system

Vibration condition monitoring system is divided into fixed installation system, semi-fixed installation system and portable system.

4.1.1 Fixed installation system

System sensor and data collection device adopt fixed installation. Data collection shall be continuous or periodic. Fixed installation system usually is used for wind turbine with complex monitoring tasks.

4.1.2 Semi-fixed installation system

System sensor adopts fixed installation. Data collection device adopts non-fixed installation; connect only during data collection. Data collection is periodic.

4.1.3 Portable system

System sensor and data collection device all adopt non-fixed installation. Data shall be collected by portable data collector. Data collection is periodic.

4.1.4 System selection principle

a) Offshore wind turbine shall adopt fixed installation system;

b) Onshore wind turbine of over 2 MW (including 2 MW) shall adopt fixed installation system;

c) Onshore wind turbine of under 2 MW can choose semi-fixed installation or portable system;

d) When the warranty expires, during the acceptance of wind turbine, it shall present the vibration condition report that is provided by wind turbine vibration condition monitoring system.

4.2 Procedure of condition monitoring

The procedure of wind turbine vibration condition monitoring includes pre-test of vibration, vibration monitoring technology, vibration baseline test, vibration routine test, etc.

3) Harmonic content. not less than 5%.

f) Voltage caused by ground potential rise that monitoring system shall be able to withstand. not less than 2000 V.

6.2 Extreme ambient temperature for storage and transport

Permissible extreme ambient temperature for device's storage and transport is -45°C ~ +85°C.

6.3 Detection unit

6.3.1 Overview

Detection unit is in wind turbine's cabin to realize the measured parameter's collection, signal conditioning, modulus conversion and data pre-processing.

6.3.2 Uncertainty

The uncertainty of sensor measurement shall be within ±1%. The uncertainty of detection unit shall be within ±2%.

6.3.3 Frequency range Sensor's linear

frequency range shall cover from 0.2 times the minimum rotation frequency to 3.5 times concerned highest signal frequency (usually it shall not exceed 40 kHz).

a) Frequency range of accelerometer sensor. 0.1Hz ~ 30kHz;

b) Frequency range of speed sensor. 1Hz ~ 2kHz;

c) Frequency range of displacement sensor. 0Hz ~ 10kHz.

6.3.4 Insulating properties

Under normal test atmospheric conditions (ambient temperature. +15°C ~ +35°C; relative humidity. 30%~60%; atmospheric pressure. 86kPa~106kPa), detect unit's energized parts such as BETWEEN power, signal and data input loop-circuit AND non-conductive metal and shell, BETWEEN unconnected electrical circuits; the insulation shall meet requirements in 6.3.4.1 ~ 6.3.4.3.

6.3.4.1 Insulation resistance

Under normal test atmospheric conditions, each circuit insulation resistance of different rated voltages shall be less than the stipulated values in Table 2.

Rated working voltage Insulation resistance requirements (measuring c) Electrical fast transient burst immunity. test grade/voltage is grade 4, ±4 kV;

d) Surge (impact) immunity. test grade/voltage is grade 4, ±4 kV;

e) Conducted disturbance immunity induced by RF field. test grade/voltage is grade 3, 10 V;

f) Power-frequency magnetic field immunity. test grade/magnetic field intensity is grade 5, 100 A/m;

g) Pulse magnetic field immunity. test grade/magnetic field intensity is grade 5, 100 A/m;

h) Damped oscillatory magnetic field immunity. test grade/magnetic field intensity is grade 5, 100 A/m; […]