Te Mihi Commissioning

Size: px

Start display at page:

Download "Te Mihi Commissioning"

Baldwin Holmes
6 years ago
Views:

1 Te Mihi Commissioning Te Mihi Power Station 01 May 2014

2 Contents 2 Part 1: Overview and Features Station Overview Control and Features Built-in Test Facilities Lessons Learnt Part 2: Testing and Mathematical Modelling Governor Testing Frequency Injection Excitation Testing PSS Part 3: Market Unit Vs Station Risk SPD Modelling

3 Part 1 THI Station Overview

4 Name Plate Data 4 Steam Turbine Generator» Make Toshiba» KVA 108,706» Phase 3» Poles 2» Hz 50» Volts 11,800» Amperes 5,319» Power Factor 0.85» Insulation Class F

5 Name Plate Data 5 Steam Turbine» Make Toshiba» Rated Output 83,507 kw» Maximum Output 91,857 kw» Rated Speed 3000 rpm» IP Steam Pressure 5.20 bara» IP Steam Temperature 153 o C» LP Steam Pressure 1.14 bara» LP Steam Temperature 103 o C» Exhaust Pressure 65 mbar

6 Steam Turbine Generator Overview 6

7 D-EHC Controller System Configuration 7

8 D-AVR Controller System Configuration 8

9 Operating & Control Features 9 Turbine» Governor Control» Automatic Load Regulation (ALR)» Load Limiter (LL)» Load Limiter Follow-up Load Regulation» Governor Follow-up Load Regulation» Inlet Pressure Regulation» Initial Pressure Control protection function» Vacuum Unloader protection function Generator» Voltage Control» Power Factor Control» MVAR Control

10 Governor Follow-up Load Regulation 10

11 Load Limiter Follow-up Load Regulation 11

12 EHC & AVR Test Facilities 12 EHC» Built-in Frequency Injection Function» Built-in Frequency Step Function» Transient Recording Capability AVR» Built-in Voltage Step Function» Built-in UEL, OQL, VPFL & OCL functions» Transient Recording Capability

13 Frequency Injection 13

14 Frequency Injection Faceplate 14

15 Transient Recorder 15

16 AVR Test Facility 16

17 Transient Recorder 17 Toshiba is capable of recording up to 5 groups of transient parameters Each group can record 8 Analog data and 32 digital Data Records faults automatically in a cyclic manner Recording can be manually triggered Currently set-up at 2 millisecond scan time and a record time of 19 seconds.

18 % Valve Position Load (MW) Factors Affecting Unit Performance Load vs Valve Position Flow Demand / Governor Setting Position (Design) Load (Design) Change in Speed Flow Demand Valve Position

19 Factors Affecting Unit Performance Steam and Ambient condition factors.» NCG in Steam» Steam Flow» Steam Pressure» Power Factors» SGW Temperature» Power Factor» Ambient Wetbulb Temperature 19

20 Good Practices 20 Good safety practices - No significant safety incidents» Constant safety vigilance pays off» Knowledge and experience of workers are vital SO s site visibility» Better coordination equals quick responses and better outcomes Open line communication to SO» Good business relationships makes good business outcomes» Things gets resolved in a more timely manner

21 Good Practices 21 OEM s professionalism and commitment to help» Site engineers in-depth knowledge of their equipment» Willingness to make system modifications to satisfy the Contract requirements Toshiba s built-in test functions» Made current and future testing alot easier

22 Areas of Improvement 22 PRESENTATION TITLE Safety procedures and documentations» Contactors should have a well-tested safety procedure and documentations for Transpower-Project interface works No definite overall project schedule» Last minute test notifications to SO/Transpower Better information dissemination down to field engineers» Vital information to be made available to commissioning engineers

23 MW System Frequency 12 November 2013 System Disturbance Time 46

24 Part 2 THI Turbine & Generator Tests and Mathematical Model

25 Governor Testing 25 EIPC requirement is to provide a verified set of modelling parameters Digital governor Therefore frequency injection selected Over frequency more relevant for geothermal Less influenced by steamfield performance

26 Frequency Injection 26

27 Gross Active Power & Speed Injection signal Turbine Speed (rpm) Over Frequency Te Mihi Over Frequency Injection Test Speed Injection Signal (rpm) Gross Active Power (MW) Turbine Speed (rpm) Time (s)

28 Excitation Testing 28 EIPC requirement is to provide a verified set of modelling parameters No significant difference for geothermal units to their hydro / thermal counterparts Step in AVR voltage setpoint tests both with PSS on and off Limiter tests (over & under excitation limits)

29 PSS Testing 29

30 Modelling Results 30

31 Modelling Results 31

32 Part 3 Market

33 Unit versus Station Risk 33 During commissioning both units are modelled as a Contingent Event (CE) risk status until each unit has passed its system ride through test (SRT). Proposed code changes in 2012 looked at causer pays for the additional reserves to cover unproven plant Contact went with unit risk and dispatch to offset the station risk - gap in the commissioning of the two units Downside is that metering changes are required

34 SPD Modelling 34 Post commissioning: Retain unit dispatch Move to station dispatch (metering changes required)

Legal Name of the Customer (or, if an individual, individual's name): Name: Contact Person: Mailing Address: Physical Address: City: State: Zip Code:

Legal Name of the Customer (or, if an individual, individual's name): Name: Contact Person: Mailing Address: Physical Address: City: State: Zip Code: Generating Facility Level 2 or 3 Interconnection Review (For Generating Facilities with Electric Nameplate Capacities no Larger than 20 MW) Instructions An Interconnection Customer who requests a Utah