-POWERFUL SOLUTIONS-HITACHI EXCITATION SYSTEM

VCS-6000

The HITACHI VCS-6000 State-of-the-Art Voltage Regulator

System Meets or Exceeds all U.S., Canadian & European

Engineering Standards

Power Plant Needs and Our Solution

Stable Power Supply

Flexible Plant Management

Centralization of Information

Quick Response & High Efficiency

Easy System Maintenance

Systems Integration

Digital-AVR

Power System Stabilizer

Human Machine Interface

Information Network

Maintenance Tool

The expansion of the power distribution

network in recent years increased the necessity for

stable operation of individual generators. Known issues

in this context are a decrease in stability as transmission

distances and load inconsistencies increase. For green

site unit projects and modernization projects, high

system efficiency and easy maintenance of control

devices are mandatory in the electric power industry.

For modernization projects, system and spare part

obsolescence are also important decision factors in

deploying a new excitation system.

The Digital Automatic Voltage Regulator and Power

System Stabilizer are the most cost effective measures

in power transmission stabilization strategies.

HITACHI’s solution is the digital, static VCS-6000

Excitation System with the integrated Power System

Stabilizer. Using a state-of-the-art 32 bit RISC

processor, the VCS-6000 integrates various functions

into the voltage control system to achieve a responsive

and reliable network.

Reasons for Excitation System Upgrade

Power Line Network

G Distribution

Network

Local

Network

Industries

& Consumer

2

Key Components of Digital-AVR Control

The primary function of the Digital AVR is regulating the

generator voltage and matching it with the voltage

reference value (90R set point). Hence, the AVR has a key

role in supplying stable voltage during power swings in the

power generation network.

Required Functions:

- Multifunction Controller

- High Reliability (system redundancy, self-diagnostic

function, compact design)

- Centralized System Supervision

- Ease of Operation, Maintenance, and Safety

- Power System Stabilizer

AVRPSS

T

G2

VG

AVR setting value

+−

Main

TransformerMain Breaker

Gn

G1

AVR: Automatic Voltage Regulator

PSS: Power System Stabilizer

Turbine

Generator

Power Grid 2

(Generator Voltage)

Local Power Oscillation(1.0Hz)

PT

Proposed improvement by means of genarator Excitation System

Inter-systemPower Oscillation

(0.3-0.5Hz)

Rotational Torque

Outline of Digital-AVR Power Stability

AVR: Maintenance of Generator Voltage

PSS: Improvement of the power system stability

Transient

Dynamic

Power Grid 1

Decrease inPower Stability

KA

3

CONTROL SYSTEM CONFIGURATION

SignalDetect

AI Control

G

DI

DO

Optic

Optic

Optic

Max 10 Parallel AC

DC

DC

DR

41 THY#n

VCMI(A)

VCMI(B)

PT-A

PT-B

EX-TR

52

Crow-

Bar

TB

PS(A)

PS(B)

GPG; Gate Pulse Generator

EX-TR; Excitation Transformer

GDIO; Gate Driver & I/O

CBC; Craw-Bar Circuit

HMI; Human Machine Interface

RDIO; Remote Digital I/O

PS; Power Source

THY#1

GDIO

AC-FCB

THY(1)

THY(2)

AVR

HMI90.6"

(2,300)

47.2"

(1,200)

(1,000)

39.4"

(1,100)

43.3"

(1,100)

43.3"

(1,000)

39.4"

(mm)inches

Typical dimensions for 375VDC / 2000ADC class

CBC

RDIORDIO

RDIORDIO

GPGSignalDetect

AI Control

HMI

GPG

VCMI; Voltage Control Module Integrated

Typical Thyristor Excitation System VCS-6000 (Redundant AVR)

Each control channel A/B has the capability to fire 10 parallel thyristor bridges. Hence, there is no limitation to the excitation rating.

Each control channel A/B has parallel control hardware for gate signal control and for I/O signal interface. Hence, there is no impact on plant operation if one channel failure occurs.

Tool

Parallel Redundant Control System Capacity Expansion

Diagnostic Identification

165.4" (4,200)

The HMI stores fault information with time stamp for both control channels.

4

VCS-6000 COMPONENTS

Example of AC Field Circuit Breaker Control System Arrangement

MAIN MENU ONLINE PROCESS MONITOR CONTROL PANEL

Fault IndicationLimiter ActionMode Selection(Local-Remote)

Channel On-Off(Master/Slave)

Scroll buttonMode SelectionAVR-AER (FCR)Var/PF On-Off

� LOCAL OPERATION / MONITORING

� COOLING FANEach THY panel has on-linemaintenance capability of the fan (hot-swap)

� GDIOGDIO supplies the gate pulse to the thyristor from the gate trigger signal received from VCMI.Functions:*Gate pulse adjustment*Digital input: 16 points*Digital output: 6 points

� RDIOMain field circuit breaker provides disconnect from excitation field circuit.AC-FCB is applicable for the ratings; 690V AC, 4,000 ADC.

� VCMI*Signal detection (V, P, Q, f, Vfdc etc.)*AVR control*Analog input: 20 points*Analog output: 7 points*Gate pulse generator*Historical trend datarecord

� FAN POWER SUPPLY

CONTACTOR

� THYRISTOR BRIDGE SECTION

Hitachi design is based on N+1 parallel redundancy as a standard.

VCMI controls these I/O signals through the optical cable transmission between RDIO and VCMI.*Digital input: 16 points*Digital output: 10 points

� AC FIELD CIRCUIT

BREAKER (41)

� HPSIHigh potential signal inter-face for signal calculation at VCMI.Input Signals:*EX-TR secondary voltage*Generator field voltage*Generator field current*Crow-bar voltage

AVR/AER SelectorExcitation ON/OFF

SelectorFCB ON/OFF

Selector

Release

Reset Alarm

� HMI(mounted on the front panel of AVR)

5

HITACHI Excitation System VCS-6000 Uses State-of-the-Art Digital Control Technology for Synchronous Machines, Providing Excellent Control and Easy Maintenance.

One simple local operation screen on front door of AVR panel prevents confusion and potential for misoperation.

Enhanced crow-bar circuit prevents energy from coming back into the control system following a collapse of the field (CEMF)

Auto tracking function between actual operating mode and other control modes for bumpless transfer.

Application of optical cable minimizes electro-magnetic

influence of signals. Application of fiber-optic cables

for gate-firing signals eliminates susceptibility to

electromagnectic interference.

VCS-6000 FEATURES

RELIABILITY

LOCAL OPERATION STABILITY & REDUNDANCY

EASE OF USE

MAINTAINABILITY

The VCS-6000 Automatic Voltage Regulator has been installed in all sizes of applications from small rotating excitation system to large static excitation system.

Selection of simplex or redundant system is available as required by the customer.

VCS-6000 assures high component reliability as a result of the following approach:

• Consolidated design results in fewer boards and less

internal wiring.

• Varnish coating for of all boards inhibits corrosion and

extends life.

Complete parallel redundant Excitation Systemthrough the following design features:

• Assuring stable plant operation by application of two parallel control channels.

• Assuring stable plant operation by implementation of N+1 Thyristor bridge circuits as standard design.

• Assuring stable plant operation by application of DC/DC & AC/DC control power supplies.

VCS-6000 provides diagnostic functions, controlfunctions and limiters as follows:

• Fault detection of each module by sophisticated self-diagnostic function.

• High-speed historical trend; records data for testing and fault analysis.

• Soft start function for prevention of generator voltage over-shooting.

•

•

• Local control panel support for quick troubleshooting using alarm history log (historian).

VCS-6000 provides excellent maintainability of the excitation control system using the Commissioning & Maintenance Tool.

• Facilitates online replacement by isolation of disfunctional control channel from operation.

• One thyristor bridge per panel assembly improves maintainability and easy identification of disfunctional bridge.

• Safe maintenance, online monitoring and tuning with Commissioning & Maintenance Tool.

ELECTRO-MAGNETIC INTERFERENCE

FLEXIBILITY

ADAPTABILITY

• Displays system parameters (Vg, Pg, Qg, etc;.) • Raise/Lower commands of reference value. • ON/OFF command and control mode selection command for excitation control for both channels in redundant system.

• Aging test for all boards.

6

EXAMPLES

VCS-6000... Competitive Advantage Through High-Tech Engineering

Fig 5 Brushless Exciter with PMG (Mainly apply for fossil power plant)

Fig 6 Brushless Exciter without PMG

Fig 7 AVR cubicle dimension (Sample)

Fig 8 AC-EX with HFG

(Mainly apply for hydro power plant)

Fig 4 500VDC

8,000A DC class

cubicle dimension

(Sample)

CT

PT

G AC -EX PMG

AVR(VCMI) CT

PT

G

PWM

AVR

HMI

(800)

31.5"

EX-TR

Brushless Exciter(BL-EX) Potential Source Rectifier Exciter(THY-EX)

Alternator-Rectifier Exciter(AC-EX)

AVR(VCMI)

PWM

110 V, 3 phase

15 A continuous, 22.5 A, 60 S

60 A continuous, 90 A, 60 S

Input

Output

PWM Rating

90.6"

(2,300)

(1,000)39.4"

Fig 9 200 VDC 200 A class

Cubicle Dimension

(Sample) 47.2"

(1,200)

AVR THY

HMI

90.6"

(2,300)

(1,000)

39.4"

(1,100)

43.3"

(mm)

inches

(mm)inches

Fig 2

375VDC 2,000 A DC class cubicle dimension

(Sample)

AC- FCB

THY (1)

THY (2) AVR

HMI

90.6"

(2,300)

47.2"

(1,200)

(1,000)

39.4"

(1,000)

39.4"

(1,100)

43.3"

(1,100)

43.3"

165.4" (4,200)

(mm)

inches

• Available maximum 10 thyristor (THY) cubicles depending on required exciter rating.

• AVR cubicle is same dimension for both single or duplicate AVR.

AC -EX

CT PT

G HFG

41 PWM

AVR (VCMI)

AC -EX

EX-TR

CT

PT

AC-FCB

AVR (VCMI)

THY

31

G

Fig 1 Apply AC-FCB (Applicable for medium capacity generator)

Tool

AVR (VCMI)

G

EX-TR

CT

PT

DC- FCB

THY

31

Fig 3 Apply DC-FCB (Applicable for large capacity generator)

AC- BUS FS

DC- BUS

THY (1)

THY (2)

THY (3)

THY (10) AVR

HMI

90.6"

(2,300)

63"

(1,600)

(mm)

inches

(800)

31.5"

(1,200)

47.2"

(1,200)

47.2"

(1,200)

47.2"

(1,200)

47.2"

(1,000)

39.4"

(1,000)

39.4"

(800)

31.5"

7

No.VCS-6000-CATA-01E2

Printed in the USA 2009(MD&A)

® Copyright 2010 Hitachi,Ltd.

All rights reserved

WORLD WIDE SUPPORT

5-2-1, Omika-cho, Hitachi-shi, Ibaraki-ken,

19 British American Blvd.

Latham, NY 12110 USA

Tel: +1 (518) 399-3616

Fax: +1 (518) 399-3929

319-1293 Japan

Tel: +81 (294) 53-1111

Fax: +81 (294) 53-2230

(Brisbane office)Sky Level. 301 Coronation Drive Milton. QLD 4064 Tel: +61 (7) 3369-3962Fax: +61 (7) 3369-8155

(European Headquarters)Power & Industrial GroupWhitebrook Park Lower Cookham RoadMaidenhead, Berkshire SL6 8YA,UKTel: +44 (1628) 58-5000Fax: +44 (1628) 58-5373

HITACHI Provides Innovative & Reliable Solutions, Products & Services World-Wide:

Hitachi Canada, Ltd.

Power & Industry Division460-10655 Southport Road S.W.Calgary, AlbertaT2W 4Y1Tel : +1 (403) 278-1881Fax: +1 (403) 278-1810

MD&A Control Systems

3825 E. Mulburry Street, Suite 2Fort Collins, CO 80524Tel: +1 (970) 224-2223Fax: +1 (970) 224-1700Email: Beckstien@mdaturbines.comwww.MDAturbines.com

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10th Floor, Hindustan Times House18-20, Kasturba Gandhi MargNew Delhi-110001Tel: +91 (11) 2331-5635Fax: +91 (11) 2331-3742

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(Headquarters)Power & Industrial Group16 Collyer Quay#20-00 Hitachi Tower,Singapore 049318Tel: +65 (6535) 2100Fax: +65 (6535) 1533

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Head Office Hitachi, Ltd.,Power SystemsAkihabara Daibiru Building, 18-13, Soto-Kanda 1-chome, Chiyoda-ku,Tokyo, 101-8608 JapanTel: +81 (3) 3258-1111

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Beijing Headquarters18/F., Beijing Fortune Building5 Dong San Huan Bei LuChao Yang DistrictBeijing 100004Tel: +86 (10) 6590-8111Fax: +86 (10) 6590-8110

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Hitachi, Ltd.Information & Control Systems DivisionPower Plant Control Systems Engineering Dept.

Mechanical Dynamics & Analysis, Ltd.

This product is protected by the following patents

and/or patent pendings.

Patent: JP3314035, JP3706960 (US5594350)

Patent Pending: JP2006-129631,

JP2005-333486, JP2003-204699