EGR-MP

Hydraulic turbines governor

Purpose

Digital governor of frequency and power for hydraulic turbines is aimed on the control of hydraulic turbines of any types: radial-axis, Kaplan, bucket and converted. For Kaplan and bucket turbines the program supports the combinatory control of the regulating organs, which depends on the opening (power) and pressure.

Basic functions:

• automatic start and stop of hydroelectric generator.
• automatic frequency adjustment of hydroelectric generator at synchronizing mode.
• runing processing methods while in the network.
• precise and high-speed execution of the task without overshoot.
• standard work during the initial frequency regulation in the network task.
• automatic switching to frequency regulation in the isolated region mode.
• integration with the systems of upper level on the basis of industrial computer networks.
• built-in rotation relays and command-apparatus.
• control of hydroagregate with one or two regulating organs.
• anti-acceleration relay protection.

Structure of control system

Governor controllers, frequency relay and intellectual operator"s panel form the local network which helps to maintain doubling the main protection function of the control system - the function of regulation of rotating speed. A special controller is used for the electro-hydraulic servo drive control.

There was developped a modification of the regulator using the DeviceNet industrial network. At the decrease of quantity of discrete and analogous channels this ensures the increase of volume and preciseness for the informational exchange with the station"s upper level.

In standard set the panel contains:

• frequency and active power regulator controller;
• rotation frequency relay and command-apparatus controller;
• Control system of servomechanism;
• Autonomous protection from aggregate"s acceleration;
• Special power supplies for solenoids of turbine automation.

The electronic part of control system is made on PC-compatible controllers manufactured for operating in hard industrial conditions and having a high reliability index.

The backed up system of electric supply, correct protection of external electric lines, high-voltage (2500V) optoisolation modules with minimal through capacities between input and output lines and corresponding controller"s modules ensure high exploitation safety and wide usage of the regulator as the part of the automated systems for different types of hydroelectric plants.

The control of servomechanism is made as a separate block on the basis of microcontroller with RISC architecture. The controller is connected with the regulator by the parallel interface. This ensures to make the process of the control system of servomechanism setup easier, provide the high accuracy and the stability of its functioning. The usage of the relay with memory as the discreet output elements fixing the regulator"s state ensures the saving of the aggregate"s condition and restoring the up-state of control system in case of occasional breakdown of controller.

Software features

Our software was developed taking into consideration the long-year experience of using the control systems for hydro-electric plant aggregates.

The system of automation of program developing for controllers is based on the function block language and is positively corresponding to the IEC 3111-3 standard requirements.

The library of function blocks contains the structures of regulators for hydro turbines recommended by the International Code of publication IEC-61362 (1997) and specially synthesized for non-minimum phase objects of the PID-laws structure, fully compensating the influence of this factor on the regulation head loop stability.

The usage of this or that structure is decided by the technical task on the control system. The options available for the operators ensure the efficient usage in the most difficult conditions of the power system.

The programs providing the automation of the setup of the electro-hydraulic servomechanism, the clean data are included in the Mathematic functions of the regulator. Also in case of controlling the Kaplan turbine within the mathematic functions there are also identifying the combinatory related functions either by the minimal shaft vibration (if accelerometer"s present) or by the maximum efficiency (if sensors of pressure in a spiral chamber are present).

Besides, the Microrocontroller of the governor controls the safe functioning of sensors, the certainty of the signals of the object and up-level control system connection line. The microcontroller also makes the events archive.

For testing a governor and for training power plant staff the specially developped sw/hw model is used. It imitates the control object (hydroaggregate) and functions on a separate PC. The model is connected to the regulator via USO interface using the opto-isolated modules.