GE IS420ESWBH2A Excitation System Control Processor Product Introduction

The GE IS420ESWBH2A​ is a critical Excitation Control Module,a core component of the GE EX2100e digital excitation system used in gas and steam turbine-driven generators.It functions as the intelligent control interface between the Mark VIe turbine control system and the generator’s field winding,responsible for precise regulation of generator terminal voltage,reactive power(VArs),and power factor.This module is essential for maintaining grid stability,generator synchronization,and overall power plant performance.

Application Scenario

In a 400 MW combined-cycle power plant,the gas turbine generator is synchronized to the high-voltage grid.During a sudden grid fault causing a 10%voltage sag,the generator must inject reactive power(VArs)to support the grid—a critical grid code requirement.The GE IS420ESWBH2A​excitation control module,receiving voltage and current feedback in real-time,instantly calculates the required field current boost.It sends a high-speed PWM(Pulse Width Modulation)signal to the thyristor-based power stage,forcing a rapid increase in the generator’s field excitation.Within 100 milliseconds,the generator ramps up its reactive power output,helping to stabilize the grid voltage.Simultaneously,the module’s advanced algorithms prevent the generator from exceeding its under-excitation or over-excitation limits,protecting the rotor windings from thermal damage.This event,managed autonomously by the IS420ESWBH2A,prevented a potential unit trip and demonstrated its role as the guardian of generator stability and a key asset for Transmission System Operator(TSO)compliance.The module’s precise control and protective functions directly contribute to grid reliability and the plant’s value as a grid-supporting asset.

Key Parameters

Main Parameters

Value/Description

Product Model​

GE IS420ESWBH2A​

Manufacturer​

General Electric(GE)

Product Category​

Excitation Control Module(EX2100e System)

System Compatibility​

GE EX2100e Digital Excitation System,Mark VIe Turbine Control

Primary Function​

Generator terminal voltage and reactive power(VAr)regulation.

Control Inputs​

Generator terminal voltage(VT),generator current(CT),field voltage/current feedback.

Control Output​

PWM signals to control the thyristor firing in the power stage.

Communication​

Integral to the Mark VIe VME rack;communicates with the turbine control processor(TCP)and HMI.

Protection Functions​

Includes over/under excitation(V/Hz)limiting,field overcurrent,and loss of signal detection.

Redundancy​

Often deployed in a dual-channel(1oo2)configuration for high availability.

Technical Principles and Innovative Values

Advanced,Multi-Loop Digital Control Architecture:​The GE IS420ESWBH2A​replaces analog regulators with a sophisticated digital control system.It runs multiple,interlinked control loops simultaneously.The primary Automatic Voltage Regulator(AVR)loop maintains terminal voltage.A parallel Power System Stabilizer(PSS)loop damps low-frequency power oscillations that can threaten grid stability.These loops use digital filters and PID algorithms that are far more precise,adaptable,and immune to drift than their analog predecessors.Parameters can be tuned via software to match the exact generator and grid characteristics,optimizing performance.

Integrated Protective Functions and Limiters:​The module is not just a controller;it is a protector.It continuously monitors for dangerous conditions.Key limiters,such as the Minimum Excitation Limiter(preventing loss of synchronism)and the Over-Excitation Limiter(protecting the rotor from thermal overload),are integrated directly into the control firmware.These are not separate devices.When a limit is approached,the module seamlessly and instantaneously overrides the normal voltage control to enforce the limit,providing smooth,bumpless protection that prevents generator trips during system disturbances.

Seamless Integration with Mark VIe for Unified Turbine-Generator Control:​The IS420ESWBH2A​is a native component of the Mark VIe control platform.It shares the same VME rack,engineering tools(ToolboxST),and HMI as the turbine controls.This integration allows for coordinated control strategies.For example,during turbine startup,the module can receive a”raise/lower”command directly from the turbine sequencing logic.More importantly,it provides a unified data environment where excitation alarms,trends,and oscillography are available alongside turbine data,giving operators and engineers a complete picture of the turbine-generator set’s health and performance.

Application Cases and Industry Value

Case Study:Black Start Capability Enhancement for a Peaking Plant

A municipal utility’s peaking plant was required to upgrade its”black start”capability—the ability to start without external grid power.A key challenge was reliably building generator voltage from residual magnetism using only the plant’s diesel starter.The existing analog exciter was unreliable.The plant retrofitted with an EX2100e system featuring the GE IS420ESWBH2A​module.The plant’s electrical supervisor explained:”The digital control of the IS420ESWBH2A​made the black start sequence bulletproof.Its software allows us to implement a precise,soft-start voltage ramp-up profile.The integrated protection prevents overvoltage during this delicate process.Since the retrofit,we have a 100%success rate on black start tests.Furthermore,the power system stabilizer(PSS)function,easily enabled in software,resolved a long-standing 0.8 Hz oscillation on our local grid,which the local transmission operator had cited us for.The excitation system,centered on this module,has transformed our unit from a simple generator into a flexible,grid-supporting resource.”This demonstrates the module’s value in enabling advanced grid support functions,enhancing plant reliability for critical missions like black start,and solving complex power quality issues through software-configurable features.

Installation,Maintenance,and Full-Cycle Support

Installation and commissioning of the GE IS420ESWBH2A​are complex tasks requiring specialized knowledge of excitation systems.The module is installed in a designated slot in the EX2100e or Mark VIe rack.Configuration involves meticulous setup of VT/CT ratios,control loop parameters,and protective limits using ToolboxST.Commissioning tests,including open-circuit and short-circuit generator characteristic tests,are critical to validate the system’s performance.

Routine maintenance is heavily reliant on the system’s diagnostic capabilities.Monitoring field winding temperature,field voltage/current trends,and the module’s internal diagnostic messages is key.Redundant channel configurations allow for testing and maintenance of one channel while the other remains in service.Our support provides access to genuine,factory-reconditioned GE IS420ESWBH2A​modules.We understand the criticality of generator excitation and can assist with compatibility verification for your specific EX2100e system and generator.We are committed to being a reliable partner in maintaining the heart of your generator’s control system,ensuring grid compliance and operational reliability.

Secure your generator’s performance and grid compliance with a digital excitation powerhouse.Contact us for a genuine GE IS420ESWBH2A excitation control module and expert support for your EX2100e system.