MNU-MP

Control system for oil pressure plants

Purpose

Control system for oil pressure plants is built up for maintaining the levels and pressure keeping within the hydraulic drive control system.

For controling middle and high power oil pressure plants "Promautomation" supplies the MNU-Mp system, which functions are maintaining the levels and pressure keeping within the hydraulic drive oil supply system and also automatic control for leakage pumps and oil cooling system.

Basic Functions

• manual and automatic keeping of the levels and pressure within the oil-supply system.
• control for oil-pumps (up to three pumps) with an option of manual and automatic priority adjustment.
• manual and automatic control for one or two leakage aggregates.
• automatic control for air compressor.
• manual and automatic control for oil cooling system.
• forming warning and emergency signals in case of failing to keep up the necessary parameters of the oil pressure plant.
• events registering.

Automatic keeping the level of pressure and oil level in the oil tank is maintained by joint operation of oil pumps and air compressor (one or two). If pressure sensor breaks down the system can keep on working for some time using level sensor only. Control for air compressor is blocked.

The basic mode of functioning for the system is automatic. But at any moment it is possible to switch to manual control for oil pumps and leakage aggregates (for example when a definite sensor breaks down), in this case warning signalization turns on automatically.

In case of emergency fall of oil level the corresponding informational relays switch on. All the malfunctions stated in the process of work are registered in the events archive (in addition to warning signalling system)

Control system structure

The autonomously made system is placed in a panel of one-side access. Size - 1600x600x600 mm. The system contains the complete set of equipment necessary for control of all elements of an oil pressure device: pumps, bypass valves, air compressors, oil coolers and leakage aggregates.

The electronic part of control system is made on PC compatible controllers produced by the US company OCTAGON SYSTEMS. These controllers are to be used in hard industrial conditions and they showed the high safety.

The electric supply system is double. Input and output lines of the system meet all the requirements for a hydroelectric plant. Discreet and analogous input and output modules ensure the galvanic division of the controller lines and of the sources of signals with potentials distinction up to 2500 V. For commutation of governing lines relays are used.

Software features

The software is developed using graphic programming environment POLYGON (created by Promautomation). The debugger integrated into development environment ensures the real time control for the values of any input or output signals. The debugger also controls any known to the controller parameters of control process for the subsystems of the device.

Control algorithms were developped jointly with specialists from "LMZ" factory. Except the standard functioning modes there is also the mode with automatic switching of pumps priorities. This mode ensures the proportional load distribution on all pumps working, thus improving their thermal conditions and making possible to find possible malfunctions in the control lines and in the pumps.

The efficiency test is implemented on a special imitating device displaying the processes of oil accumulation in the tanks, changes of pressure, level and temperature in the accumulating tank, oil pumps, air compressor, bypass and non-return valves turned on.

Control systems for smaller hydro power plants aggregates

For the control of smaller hydro power plants aggregates there was developed a system uniting controling functions of oil pressure plant and auxiliary mechanisms, rate governor, rotation frequency relay and monitoring function for all units of the turbine. The project includes the technical decisions used in EGR-MP and MPU-MP, which proved their high reliability in work. The software is developed on the basis of serial software supplied with the above described panels.

There is an option of supplying the system without operations staff. Serial turnout starts in the 3rd quarter of year 2003. Full readiness to supply with the system is four months after the signing an agreement.