The firing block accepts the field current reference and the field voltage reference and then selects the least of the two. This signal is passed on to the bridge only if the instantaneous overcurrent or the stop commands are not a ctivated. If either of these are active, the firing signal is a preset retard limit (refer to Figure 3-9).
GEH-6375A User's Guide Chapter 3 Software System Overview • •• • 3-5
Table 3-1. Standard Software Functions
Function Inputs Adjustable Constants Outputs AVR Ramp Auto Increase (RF1@IN)
Auto Decrease (RF1@DC) Manual Active (RF1@VE) Go to Preset (RF1@3E) Track Enable(RF1@T2) Track Value(RF1@2E)
High limit (RF1THO) Low limit (FR1TLO) Ramp rate (RF1NRT) Preset value (RF1@T3) Track lag (RF1WLG) Reference out AVR Setpoint Frequency (ASP@FQ) React. Cur.(ASP@IQ) REF Out (ASP@RO) UEL Out (ASP@UE) PSS Out (ASP@PV) Auto/Man (ASP@AC)
Extra Input (ASP@EX) PT Fail (ASP@PT) Gen Volts (ASP@VM) PSS Armed (ASP@PC) Gen Watts (ASP@WT) PT Fail Reset (ASP@PR)
ASP Limit High (ASPHLM) V/Hz Gain (ASPVHZ) RCC Gain (ASPRCC) PSS High Watt (ASPHIW) PSS Low Watts (ASPLOW)
AVR Ref Auto Active Man Active PSS Active V/Hz Active UEL Active Setpoint In Limit Latched PT Fail FCR FCR Setpoint FCR@SP FCR Enable FCR@EN FCR Alternate Setpoint FCA@SP FCR Alternate Enable EFA@EN FCR Prop Gain (RGKC0) FCR Integral Gain (IRWIC0) Alt FCR Prop Gain (IRGKA0) Alt FCR Integral Gain
(IRWIA0)
FCR Output ILOP0
AVR Generator Volts (AVR@FB) FVR Output (AVR@TV) AVR Ref (AVR@SP)
Manual Active (AVR@TC) Bridge Fire Enabled (AVR@ZC)
High Limit (AVRPLM) Low Limit (AVRNLM) Prop. Gain (AVRPGN) Integral Gain (AVRIGN) Tracking Gain (AVRTGN)
AVR Out AVR In Limit AVR Error
FVR Ramp Manual Increase (SS) Manual Decrease (SS) Auto Active (RF2@2E)
Go To Preset (RF2@3E) High limit (RF2TH0) Low limit (RF2THL) Ramp rate (RF2NRT) Preset value (RF2@T3) Reference Out
FVR Field Current (IFE) AVR Out (EFR@TV)
FVR Ref (EFR@SP) Auto Active (EFR@EN)
Bridge Fire Enabled (MPWRENAB)
FVR Turn Off (FLDZVL) Tracking Gain (FLDTGO) Proportional Gain (FLDPGO) Integral Gain (FLDIGO)
3-6 •• • • Chapter 3 Software System Overview EX2000, PWM Digital Regulator GEH-6375A
Table 3-1. Standard Software Functions - Continued
Function Inputs Adjustable Constants Outputs UEL Watts (RA1@I1)
Gen. Volts(@INPUT) Vars (R2@FBO)
Vars Ref. 0 (FGENYO) Watts Ref. 1 (FGENX1) Vars Ref. 1 (FGENY1) Watts Ref. 2 (FGENX2) Vars Ref. 2 (FGENY2) Watts Ref. 3 (FGENX3) Vars Ref. 3 (FGENY3) Watts Ref. 4 (FGENX4) Vars Ref. 4 (FGENY4) Prop. Gain KP (R2KFBO) Integral Gain KI (R2WI_0) High Limit (R2LMPO) Low Limit (R2LMNO)
UEL Output
OEL Field Current (CURRENT)
High Limit (CRLMHI) Low Limit (I2tAFL) FCR Preset (PIT@RS) Inst. Overcur. Lim (PITPU) IIT Limit (PITLM)
FCR Pos. Limit (FCRPLM) IIT Cooling Mult. (I2tCMT)
OEL Act (FLDMOD) IIT Acc (PITIACCM)
Firing Block FVR Out FCR Out IOC Active Start/Stop
GEH-6375A User's Guide Chapter 3 Software System Overview • •• • 3-7 SETPOINT EXIREAC RCC EXWATTS UEL EXXMAG EXVMAG DETECT PT FAIL LOWER RAISE SETPOINT REG AUTO EXVFREQ V/HZ + + + LOWER RAISE REG. MAN AUTO/MAN MAN AUTO PI LOGIC SELECT REGULATOR REGULATOR IFE EXVMAG - + PI - + PI FIRING BRIDGE AUTO EXCITER FIELD
VAR/PF CONTROL, POWER SYSTEM STABILIZER AND PT FAIL DETECTION ARE OPTIONAL. ALL OTHER FUNCTIONS SHOWN ARE STANDARD.
IFE EXVARS EXVMAG VOLTAGE LIMIT GATE LOW VALUE SPARE - PSS EXWATTS Pa ZERO LEVEL + ARM PSS VAR CONTROL /PF EXWATTS EXVARS RUNNING 1177S AND FCR@SP FCA@SP SLD1 52G HIGH SP LOW SP OFFLINE ONLINE I*T LIM
3-8 •• • • Chapter 3 Software System Overview EX2000, PWM Digital Regulator GEH-6375A
Figure 3-2. Automatic Voltage Regulator (AVR) Ramp
] ] ] ] ] ] ] ] ] ] ] ] ] ] ] ] ] ] ] + + + + + + -
GEH-6375A User's Guide Chapter 3 Software System Overview • •• • 3-9
Figure 3-4. Automatic Voltage Regulator (AVR )
3-10 • •• • Chapter 3 Software System Overview EX2000, PWM Digital Regulator GEH-6375A
Figure 3-6. Field Regulator (FVR )
GEH-6375A User's Guide Chapter 3 Software System Overview •• • • 3-11
3-12 • •• • Chapter 3 Software System Overview EX2000, PWM Digital Regulator GEH-6375A
GEH-6375A User's Guide Chapter 4 Software Configuration and Scaling • •• • 4-1
Chapter 4 Software Configuration and
Scaling
Introduction
This chapter gives examples of the scaling for specific parameters in a generic brushless regulator generator application.
Section Page
Configuration and Scaling Example... ... 4-2 Example Generator, Exciter, and Regulator... ... 4-3 General Configuration ... 4-4 Feedback Scaling ... 4-6 Generator Feedback... ... 4-6 Bridge Voltage Feedback... ... 4-7 Bridge Current Feedback ... 4-8 Feedback Offsets... 4-8 Instantaneous Overcurrent Trip... 4-9 Regulator Scaling... 4-9 Automatic Voltage Regulating System... 4-9 Under Excitation Limiter (UEL) ...4-13 Reactive Current Compensator (RCC) ...4-16 VAR/Power Factor Control ...4-17 Field Regulator (FVR)...4-18 Field Current Regulator (FCR) ...4-20 Optional Functions Scaling and Configuration...4-23 Transducer Outputs ...4-23 Ground Detector and Diode Fault Monitor...4-24 Field Thermal Model...4-25 The software to configure various regulators, metering, and protective functions within the regulator operates on a count system representing actual feedback values. These feedbacks are generated by current transformers, voltage transformers, and dc shunts. The signals may pass through isolators and amplifiers. These analog signals are transformed to digital signals by voltage controlled oscillators.
4-2 •• • • Chapter 4 Software Configuration and Scaling EX2000, PWM Digital Regulator GEH-6375A
The regulator controls use standard normalized values to represent the variable being monitored or regulated. This enables the use of software that, to a large extent, is not application dependent. For example, the automatic voltage regulator (AVR) controls the generator terminal voltage based on a setpoint chosen by the operator. For any machine, 1 per unit (or rated terminal voltage) is defined within the AVR to be 20000 counts. If the operator chooses to set the terminal voltage at rated then the reference to the AVR is 2 0000 counts. The voltage feedback counts are compared to this reference to generate an error signal and the appropriate control action takes place to maintain the feedback counts at 20000.
The actual generator terminal voltage being regulated is n ot referenced at this control level. It is therefore necessary to ensure that the feedback counts seen by the
regulators are adjusted to provide the standard n umber of counts when the generator is operating at rated. This is r eferred to as scaling.
An EX2000 system can be constructed several ways to accommodate customer system requirements. For example, the regulator can be fed from the permanent magnet generator or from an auxiliary bus. It can be a brushless regulator or an SCT control winding regulator. The controls are set to match the hardware used. This is known as configuration.