GESPEEDTRONIC™ Mark VI Turbine Control System

Introduction

The SPEEDTRONIC™ Mark VI turbine control

is the current state-of-the-art control for GE turbines that have a heritage of more than 30 years

of successful operation. It is designed as a complete integrated control, protection, and monitoring system for generator and mechanical

drive applications of gas and steam turbines. It is

also an ideal platform for integrating all power

island and balance-of-plant controls. Hardware

and software are designed with close coordination between GE’s turbine design engineering

and controls engineering to insure that your control system provides the optimum turbine performance and you receive a true “system” solution. With Mark VI, you receive the benefits of

GE’s unmatched experience with an advanced

turbine control platform. (See Figure 1.)

Architecture

The heart of the control system is the Control

Module, which is available in either a 13- or 21-

slot standard VME card rack. Inputs are

received by the Control Module through termination boards with either barrier or box-type

terminal blocks and passive signal conditioning.

Each I/O card contains a TMS320C32 DSP

processor to digitally filter the data before conversion to 32 bit IEEE-854 floating point format.

The data is then placed in dual port memory

that is accessible by the on-board C32 DSP on

one side and the VME bus on the other.

In addition to the I/O cards, the Control

Module contains an “internal” communication

card, a main processor card, and sometimes a

flash disk card. Each card takes one slot except

for the main processor that takes two slots.

Cards are manufactured with surface-mounted

technology and conformal coated per IPC-CC830.

I/O data is transmitted on the VME backplane

between the I/O cards and the VCMI card

located in slot 1. The VCMI is used for “internal” communications between:

■ I/O cards that are contained within its

card rack

■ I/O cards that may be contained in

expansion I/O racks called Interface

Modules

■ I/O in backup <P> Protection

Modules

■ I/O in other Control Modules used in

triple redundant control

configurations

■ The main processor card

The main processor card executes the bulk of

the application software at 10, 20, or 40 ms

depending on the requirements of the application. Since most applications require that speSPEEDTRONIC™ Mark VI Turbine Control System

GE Power Systems ■ GER-4193A ■ (10/00) 1

Figure 1. Benefits of Speedtronic™ Mark VI

• Over 30 years experience

• Complete control, protection, and

monitoring

• Can be used in variety of applications

• Designed by GE turbine and controls

engineering

ific parts of the control run at faster rates (i.e.

servo loops, pyrometers, etc.), the distributed

processor system between the main processor

and the dedicated I/O processors is very important for optimum system performance. A QNX

operating system is used for real-time applications with multi-tasking, priority-driven preemptive scheduling, and fast-context switching.

Communication of data between the Control

Module and other modules within the Mark VI

control system is performed on IONet. The

VCMI card in the Control Module is the IONet

bus master communicating on an Ethernet

10Base2 network to slave stations. A unique poling type protocol (Asynchronous Drives

Language) is used to make the IONet more

deterministic than traditional Ethernet LANs.

An optional Genius Bus™ interface can be provided on the main processor card in Mark VI

Simplex controls for communication with the

GE Fanuc family of remote I/O blocks. These

blocks can be selected with the same software

configuration tools that select Mark VI I/O

cards, and the data is resident in the same database.

The Control Module is used for control, protection, and monitoring functions, but some

applications require backup protection. For

example, backup emergency overspeed protection is always provided for turbines that do not

have a mechanical overspeed bolt, and backup

synch check protection is commonly provided

for generator drives. In these applications, the

IONet is extended to a Backup Protection

Module that is available in Simplex and triple

redundant forms. The triple redundant version

contains three independent sections (power

supply, processor, I/O) that can be replaced

while the turbine is running. IONet is used to

access diagnostic data or for cross-tripping

between the Control Module and the

Protection Module, but it is not required for

tripping.

Triple Redundancy

Mark VI control systems are available in

Simplex and Triple Redundant forms for small

applications and large integrated systems with

control ranging from a single module to many

distributed modules. The name Triple Module

Redundant (TMR) is derived from the basic

architecture with three completely separate and

independent Control Modules, power supplies,

and IONets. Mark VI is the third generation of

triple redundant control systems that were pioneered by GE in 1983. System throughput

enables operation of up to nine, 21-slot VME

racks of I/O cards at 40 ms including voting the

data. Inputs are voted in software in a scheme

called Software Implemented Fault Tolerance

(SIFT). The VCMI card in each Control

Module receives inputs from the Control

Module back-plane and other modules via “its