IS220PGENH1A - IO PACK, GENERATOR PLU

The IS220PGENH1A is a Turbine Generator Monitor Module designed for the Mark VIe system. The electrical interface between one I/O Ethernet network and the TGNA turbine generator is provided by the Mark VIe Turbine-Generator Monitor (PGEN). The pack includes a processor board that is shared by all Mark VIe distributed I/O packs as well as an acquisition board. The pack monitors turbine mechanical power using three analog channels and voltage or 4-20 mA sensors.

Functional Description

A current transformer input is used to monitor each phase of the generator armature current. The PGEN performs the power load unbalances (PLU) function that the Mark VI VGEN did. It lacks the power calculations (kW, kVARS, KVA) and early valve actuation logic found in the VGEN. Dual RJ45 Ethernet connectors and a 3-pin power input provide power to the pack. For simplex or TMR applications, the PGEN supports single Ethernet networks. Output is via a DC-37 pin connector that is directly connected to the associated terminal board connector. LED indicator lights provide visual diagnostics.

Compatibility

PGENH1A functions with the turbine-generator Terminal Board (TGNA). The number of I/O packs used in a signal path is referred to as the control mode:

• Simplex employs a single I/O pack and a single network connection.
• TMR employs three I/O packs, each with one network connection.

IS220PGENH1A Installation

• Securely mount the terminal board of choice.
• Insert one PGEN I/O pack for simplex or three PGEN I/O packs for TMR directly into the terminal board connectors.
• Use the threaded studs next to the Ethernet ports to mechanically secure the packs. The studs fit into a terminal board-specific mounting bracket. The bracket should be positioned so that no right angle force is applied to the DC-37 pin connector between the pack and the terminal board. The adjustment should only be needed once during the product's lifetime.
• Connect only one Ethernet cable. The pack can be used with either port.
• Connect the pack to power by plugging in the connector on the pack's side. Because the I/O pack has inherent soft-start capability that controls current inrush on power application, it is not necessary to disconnect power from the cable before plugging it in.
• Configure the I/O pack as needed using the ToolboxST application.

Processor features

• Processor with high speed, RAM, and flash memory
• Two 10/100 Ethernet ports with connectors that are completely independent of one another
• Reset circuit and hardware watchdog timer
• Sensor for local ambient temperature
• LED status indicators
• Electronic identification and the ability to read IDs from other boards
• Significant programmable logic to support the acquisition board
• Soft start/current limiter input power connector
• Power supplies on-site, including sequencing and monitoring

Auto-Reconfiguration

• The Auto-Reconfiguration feature allows the operator to replace I/O packs without having to manually reconfigure each pack or module. When the controller detects an I/O pack booting with a different configuration and the Auto-Reconfiguration feature is enabled, a reconfiguration file is automatically downloaded from the controller to the I/O pack.
• The bootload, baseload, firmware, and parameters are all reconfigured. Unless it already has the latest version, each I/O pack is updated with the current configuration that matches the configuration used by the controller.
• While an Auto-Reconfiguration is running, the controller will not allow a reboot until the Auto-Reconfiguration is complete. Other I/O pack downloads cannot be started while it is being Auto-Reconfigured. Auto-Reconfiguration only performs diagnostics if an I/O pack is already running.

Turbine-Generator Monitoring Hardware

• An analog filter acquisition board is part of the PGEN application-specific hardware (BPAIH3). To improve analog-to-digital resolution, the analog filter acquisition board provides signal conditioning to center and amplify the signal.
• For three mechanical power sensors and three CT currents, the PGEN accepts analog input signals from the terminal board. An analog multiplexer block, several gain and scaling sections, and a 16-bit analog-to-digital converter comprise the analog input section (ADC).
• Depending on the input configuration, the three analog mechanical power inputs can be configured as 5 V, 10 V, or 4-20 mA scaled signals.
• The three current inputs are brought through 250 burden resistors on the terminal board if configured as 4-20 mA signals. At 20 mA, this resistance produces a 5 V signal. When configured for current inputs, the terminal board includes a 250 burden resistor that produces a 5 V signal at 20 mA.

Power Load Unbalance Overspeed Control

• The Power Load Unbalance (PLU) function measures the difference between per unit steam turbine power and per unit generator power based on generator current. A PLU event occurs when the turbine per unit power is 40% greater than the generator power and the difference meets both the rate of change and the duration requirements. When a PLU event is detected, the steam turbine control and intercept valves (CVs) are closed to reduce power. The Iopack (PGEN) and the (TGNA) terminal board monitor the PLU.
• The PLU function can be used in either a TMR or a Simplex configuration. The steam turbine CV and IV valves are controlled by the Mark VIe Digital Output IOpack, PDOA, and TRLY (Simplex, H1F TMR) (TRLY) or terminal board. The PGEN controls the relay state on the PDOA.
• A peer-to-peer multicast packet that provides a fast communication path improves the control of the relays in the PDOA. The fast communication path runs alongside the normal pack-to-pack communication, which is routed through the signal space by the controller to transfer relay commands. The multicast path is only used to send commands to the relays.

IS220PGENH1A Diagnostics

The following self-diagnostic tests are performed by the pack:

• A power-on self-test that includes RAM, flash memory, Ethernet ports, and most processor board hardware checks.
• Constant monitoring of internal power supplies for proper operation
• A check of the terminal board, acquisition board, and processor board electronic ID information to confirm that the hardware set matches, followed by a check that the application code loaded from flash memory is correct for the hardware set.
• Hardware limit checking is performed on each analog or current input based on preset high and low levels near the end of the operating range. If this limit is exceeded, a logic signal in signal space is set to Unhealthy, and the unhealthy signal is forced to zero volts or mA. If the signal returns to its limits, the signal state returns to Healthy. If any of the signals is abnormal, the logic signal L3DIAG-PGEN is activated.
• System limit checking is performed on each input based on configurable high and low levels. These limits can be used to generate alarms, enable/disable devices, and as latching/non-latching switches.
• Precision reference voltages are included in each scan by the analog input hardware. The measured values are compared to the expected values to confirm the health of analog to digital circuits.