Diagnostics. Lesson 3. Ewen Ritchie Krisztina Leban

Transcription

1 Diagnostics Lesson 3 Ewen Ritchie Krisztina Leban 1

2 1. Converter faults - General 2. PMSM + Inverter 3. IM + Inverter 4. DFIG + Inverter 6. Hybrid EV + Matrix converter 8. Monitoring - SCADA 5. References 2

3 When Dealing with Faults Monitor healthy systems Prevent system shutdown the fault is incipient Identify fault after shutdown Fault ride-through surviving the fault [11] 3

4 Fault Industrial Plants high nonlinearity noisy signals uncertainty [11] 4

5 Fault Diagnosis Systems Using Hardware Redundancy - uses multiplication of physical devices - voting system - detects the fault and its location in the system - expensive need of extra equipment Using Analytical Redundancy. - redundant functions between system variables - no extra equipment is necessary [11] 5

6 Fault diagnosis Task -consists of two main stages: residual* generation algorithm decision making - examining the residual signals to locate and isolate the fault *A residual - procedure for extracting fault symptoms from the system, using available input and output information;fault indicator, based on deviation between measurements and modelequation-based computations [11] 6

7 Modeling Systems with Faults Compromise between model complexity and fault simulation results If linearity cannot be assumed, linearise the system around a few operating points Modeling errors affect the performances of the fault diagnosis - especially for nonlinear systems [11] 7

8 Modeling Systems with Faults - Approaches stochastic algorithms -for random processes - neural networks - fuzzy logic-based systems - neuro-fuzzy hybrids evolutionary - genetic algorithms [11] 8

9 PMSM+INVERTER 9

10 Inverter + PMSM 10

11 Faults in the voltage source inverters (PMSM) 1) DC link capacitor short-circuit fault 2) Open-circuit fault of inverter switch When the short 3) Short-circuit fault of inverter switch [1] 11

12 Faults in the voltage source inverters (PMSM) 1) DC link capacitor short-circuit fault detected by the DC link voltage sensing circuits. 2) Open-circuit fault of inverter switch - abnormal over-current flows through inverter and machine, - one of the over-current effects demagnetization fault of the PMSM - the current distortion of the machine causes noise and vibration in the driving system - bearing problem. - open-circuit fault slow response compared with short-circuit fault. - detection methods for open-circuit damage of a switch voltage sensing devices - some methods have slow responses - several current vector cycles pass before detecting - possibility of wrong detection due to the indirect current sensing. 3) Short-circuit fault of inverter switch - over-current - detection circuit. [1] 12

13 Conventional Switch Open Fault Detection Method -use of a voltage sensor - sense the actual voltage applied to each phase of the machine for the open-switch fault detection. The voltage sensors can be inserted at the desired location to detect the open-switch fault. According to the location of voltage sensors, the detection techniques can be classified as follows. 1) Terminal voltage measure method 2) Line voltage measure method 3) Phase voltage measure method 4) Neutral voltage measure method [1] 13

14 Open Fault Detection Method voltage sensor These methods -have the relatively short fault detection time fault measured when happens -require the additional hardware - voltage sensors and isolation circuits. -inverter output is PWM generated expensive: voltage sensors and isolation circuits which detect the small amount of voltage drops in the switches, large reverse voltages, and turn on/off delay time are required to have high resolution gate drive circuit for the open-switch fault detection. -When the switches are turn on, the fault is judged by measuring the voltage drops of the switches. 14

15 Open Switch Diagnosis 1. Built in voltage sensor *only applicable to a specific gate drive circuit, *hard to detect the faults when the gate drive circuit is broken. [1] 15

16 Open Switch Diagnosis 2. Analyzing Current Vector Trajectory *detects the open-circuit fault in a phase leg without additional hardware *detection by observing the difference between actual current and reference current. * causes fault detection time delay - observing and saving the current vector trajectory of one cycle. *needs large memory space to save the current vector trajectory *no practical use in slow speed region - requires more memory space. *fault detection method suited for sinusoidal current control scheme. *may give detection errors at the high speed region and transient state (when the current suddenly changes). [1] 16

17 Voltage Distortion In The Normal Switches [1] 17

18 IM+INVERTER 18

19 InductionMotor Drive Faults [3] 19

20 Voltage fed inverter induction motor drive system Various types of faults that can be classified as follows: 1) Input supply faults. 2) Three phase rectifier faults. 3) Three phase inverter faults. 4) Induction motor faults. [3] 20

21 DFIG+INVERTER 21

22 Doubly-FedInductionGenerator [6] 22

23 Open Switch Faults on Doubly-fed Induction Generator -local effect - current flowing through the faulty converter -global effect is an effect on other system variables. the current of the faulty phase loses one half cycle every period, either positive or negative depending on whether the top or bottom switch is faulty. The current waveform of the faulty phase is similar to the current waveform of a halfwave rectifier. According to the assumption that the summation of all three-phase currents is zero (ia + i + ic = 0) the other two healthy phase currents have DC offset. This local effect is presented in Fig 2. [6] 23

24 Fault Waveforms Rotor currents with one open switch fault of the machine side converter open Line side converter currents with one open switch fault of the line-side converter open [6] 24

25 OpenSwitch Fault Global effects -open switch fault does not immediately damage the converter or cause any protection system to trip, -can cause severe damage to the mechanical parts of the generator and the turbine. Generally, the operating speed of the DFIG is in the range of 3300 above and below synchronous speed. The frequency of the rotor current referred to a stationary reference frame will then vary from 0 to 3300 of line frequency. [6] 25

26 Open Switch Fault Stator Currents Line Side Converter Currents Figures: the effect of an open switch fault at phase A of the machine-side converter under super synchronous generation. [6] 26

27 Open Switch Fault Machine Side Converter Electromagnetic Torque Stator Active and Reactive Power [6] 27

28 DFIG Inverter Open Switch Fault Symphtoms machine-side converter fault : - torque oscillations which may cause - low frequency speed oscillations and - low frequency vibration of the generator shaft an open switch fault in the machine side converter can also cause a low frequency oscillation of the stator P and Q of the generator. [6] 28

29 Spectrumof Torque Under Healthy Condition Open Switch Fault Machine Side Converter [6] 29

30 Line-Side Converter An open switch fault has less effect than a fault in the machineside converter. The effect on generator variables is negligible. There is no significant oscillation appearing on the stator active power and reactive power signal as well as stator current. However, once the open switch fault appears in the line side converter, there is a DC component appearing on all three phase currents of the line-side converter. This can cause saturation in the inductor filter and the transformer. 30

31 Open Switch Fault Line-Side Converter Stator Active and Reactive Power Stator Currents 31

32 Open Switch Fault Diagnosis Methods Park's Vector Method Slope Method Control Deviation Method Normalized DC Current Method Modified Normalized DC Current Method Simple DC Current Method [1] 32

33 HYBRIDEV Dirive 33

34 Hybrid Electric Vehicle [7] 34

35 Control of HEV Drive [7] 35

36 By using the matrix converter-the large dc-bus capacitor can be removed. [7] 36

37 Four-leg-based fault tolerant matrix converter faulty module is isolated the controller replaces the faulty leg with the redundant one the developed fault-tolerant matrix converter drive can maintain sinusoidal input and output currents, even under fault situations. the function of breaking is performed by the clamp circuit of the matrix converter [7] 37

38 Fault Tolerant Control Flowchart [7] 38

39 SCADA Supervisory Control And Data Acquisition 39

40 SCADA SCADA is an application that collects data from a system and send them to a central computer for monitoring and control usages. Remote measurements, reporting data and monitoring information are known as telemetry. SCADA Hardware: -A SCADA (RTU) system is made of a number of remote terminal units - collects data and sending them back to the main station. (wire, fiber optic, radio, telephone line, GPRS and even satellite.) -The main station (or centre) collects data from the different RTUs and drives an interface to display information and control the remote sites. SCADA Software: -open source or proprietary; compatibility problems between the two [12] 40

41 Condition monitoring [12] The collection of data, communicating, transferring, analysing and finally displaying the information on operator screens is extremely important and can be seen in a supervisory control system known as SCADA 41

42 Obtaining Residuals Signal analysis: a model-free method based on time and frequency signal analysis which are state-of-the-art in process monitoring. Spectrum analysis method - includes Fourier Transformer - developed curves which derive faults. This method has successfully been applied to estimate lifetime and other diagnosis purposes especially in rotating machinery [12] 42

43 Methodology [12] 43

44 FACTS Background Fault Ride-Through Flexible AC Transmission System (FACTS) -solutions for fast dynamic control of the interrelated parameters (voltage, impedance, and phase angle) of high voltage AC transmission systems results: increased power transfer capability, increased power system security, reliability availability increased dynamic and transient stability of the power system grid. Devices for controlling and optimizing the dynamic performance of power system include STATCOM Static Synchronous Series Compensator (SSSC) Unified Power Flow Controller (UPFC). [14] 44

45 The STATCOM Fault Ride-Through The STATic Synchronous COMpensator (STATCOM) is a shuntconnected reactive power compensation device has the capability of absorbing and/or generating reactive power. Reactive power must be fed into the short circuit- VPP-fault ride-through The STATCOM output varied to control the interrelated parameters of an electric power system. The main building block of STATCOM is a Voltage Source Converter (VSC) -the VSC output+ relatively small reactance (which is provided by either a reactor or the leakage inductance of a coupling transformer). [14] 45

46 End. see refs.. 46

47 [1]Simple Switch Open Fault Detection Method of Voltage Source Inverter Shin-MyungJung, Jin-SikPark, Hyoung-SukKim, Hag-WoneKim, and Myung-Joong Youn Department of Electrical Engineering and Computer Science, KAIST /09/$ IEEE [2]Failure-Mode Analysis and Protection of Three-Level Neutral-Point-Clamped PWM Voltage Source Converters Fei Wang, Fellow, IEEE, Rixin Lai, Student Member, IEEE, Xibo Yuan, Student Member, IEEE, Fang Luo, Student Member, IEEE, Rolando Burgos, Member, IEEE, and Dushan IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 46, NO. 2, MARCH/APRIL 2010 [3]DEVELOPMENT OF AN EXPERT SYSTEM TO FAULT DIAGNOSIS OF THREE PHASE INDUCTION MOTOR DRIVE SYSTEM A.M.Elsaadawi- A.E.Kalas and M.Fawzi /08/$ IEEE /08/$ IEEE [4]Low Order PWM Inverter Harmonics Contributions to the Inverter-Fed Induction Machine Fault Diagnosis BilalAkin, Student Member, IEEE, UmutOrguner, Student Member, IEEE, HamidA. Toliyat, Fellow, IEEE, and Mark RaynerIEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 55, NO. 2, FEBRUARY 2008; /$ IEEE [5]Fault Diagnosis of Frequency Convert System Based on Networked Virtual Instrument YunfeiLi GeChen /09/$ IEEE [6]Open Switch Fault Diagnosis for a Doubly-Fed Induction Generator W. Sae-Kokand D M Grant Department of Electronic and Electrical Engineering, University /07/$ IEEE [7]Phase-Redundant-Based Reliable Direct AC/AC Converter Drive for Series Hybrid Off-Highway Heavy Electric Vehicles SangshinKwak, Member, IEEE, TaehyungKim, Member, IEEE, and GwangminPark /$ IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 59, NO. 6, JULY 2010 [8]Convert System Based on Networked Virtual Instrument Yunfei Li Ge Chen /09/$ IEEE [9]Failure-Mode Analysis and Protection of Three-Level Neutral-Point-Clamped PWM VoltageSource Converters Fei Wang, Fellow, IEEE, Rixin Lai, Student Member, IEEE, XiboYuan, Student Member, IEEE, IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 46, NO. 2, MARCH/APRIL 2010 [10]Fang Luo, Student Member, IEEE, Rolando Burgos, Member, IEEE, and Dushan /$ IEEE SEMI-CONVERTER FAULT DIAGNOSIS IN DC MOTOR DRIVES, BY PARK'S VECTOR APPROACH A. J. Marques Cardoso and A. M. S. MendesPower Electronics and Variable Speed Drives', September 1996, Conference Publication No. 429, 0 IEE, 1996 [11] Computational Intelligence in Fault Diagnosis Advanced Information and Knowledge Processing, Computational Intelligence Methodologies in Fault Diagnosis: Review and State of the Art Cosmin danut Bocaneala and Vasile Palade, 2006, 1-36, DOI: / _1 47

48 [12] Wind Turbine Condition Monitoring System 3 Month PhD Progress Report By Mani EntezamiSupervisors Dr. Stuart HillmansenDr. Clive Roberts 11 January 2010 University of Birmingham SCHOOL OF ELECTRONIC, ELECTRICAL AND COMPUTER ENGINEERING [13]High Voltage Ride Through with FACTS for DFIG Based Wind urbinesc. Wessels, F.W. Fuchs Institute of Power Electronics and Electrical Drives, [14]Modelling of Two-level, Multi-Pulse Voltage Source Converter for FACTS Systems M. K. Jalboub, H. S. Rajamani, J.C. Readle, R. A. Abd-Alhameed, A. M. Ihbal ICEGES 2009 Le Royal Hotel Amman, Jordan November, International Conference and Exhibition on Green Energy & Sustainability for Arid Regions & Mediterranean Countries School of Engineering, and Design and technology 48