BEF

Hydroaggregate model

Purpose

To provide a quick startup of a hydro turbine regulator on the customer"s object it is necessary for the supplier to make the full test of the system. To our mind, the only way, which allows making such a test, is to create a complex model.

The hydro-aggregate model, which we created, is a program-hardware complex imitating aggregate"s behavior in different modes and run by different controlling operations. It is essential that the model should be external and independent from the control panel since it is switched to it via the regular terminal strip. The model receives the controlling signals from the regulator control panel and forms electrical signals from the turbine "sensors".

Model structure

Functionally the model includes:

• mathematical models of a hydro aggregate and power system, which imitate the aggregate"s behavior during its work in various circuit-operating conditions (isolated region with varied parts of ohmic and engine load, powerful circuit with different level of aggregate"s influence on the frequency within it);
  
• mathematical models of a regulator and electro hydraulic control system;
  
• software imitator for regulator control commands and its signals with graphic interface;
  
• communication device for the model and the regulator. Communication to be implemented via regular i/o channels.
  

Mathematical model of hydro aggregate allows approximating dependences of static torque and consumption characteristics from positions of regulating organs (one or two) and the current pressure for the concrete runner. Preciseness of modeling is definitely determined by the data provided by the runners suppliers or the information received after natural testing. Modeling of hydroblow is implemented with or without regard to penstock elasticity depending on the characteristics of the latter. Hydroblow parameters and rotor"s time constant are configured. The load self-regulation factor can be also configured (when imitating work on isolated region).

The model of a power system allows taking into account such elements as time constant stiffness coefficient and synchronous pump damping factor. All these parameters can be changed in wide specter.

Models of regulator and electro hydraulic control system are included into a complex model set for the sake of doing a preliminary test for characteristics entry correctness and configuring settings factors for mathematical models of hydro aggregate and of the electric system.

Except the modeling preciseness control this ensures making a preliminary fitting of real regulator settings coefficient, which sufficiently speeds up the process of regulator"s delivery the customer.

Software imitator of regulator commands and controlled signals ensures forming the commands necessary for the regulator"s detailed test as well as external signals (including current pressure, group control signal and necessary digital information).

The device of model"s mathematical connection to the regulator via the regular i/o channels ensures their mutual work on the closed-circuit schedule with full galvanic bypass of all power and signal circuits. The tested regulator transmits (as a current signal 4-20mA) the values of controlling organs. The model transmits to the regulator the present calculated values of power, pressure and group task (current signals), the state of the generator switch (digital signal) and also the rotor"s rotation speed value and power system frequency value (as meanders).

Software features

Software has a two-level structure:

• lower level is the processes executing real time tasks;
  
• upper level maintains task of interaction with the user.
  

The software allows:

• saving to and load up parameters and characteristics of aggregate model from a separate file, which gives an opportunity to check the up-state of regulator with different types of hydro aggregates;
  
• modeling processes passing in the hydro aggregate, sampling increment 10 ms.
  
• Archiving regulator"s controlling commands and response signals (this ensures the control for the correct events archiving by making records)
  
• Recording and reviewing the diagrams of transients and printing out (up to 8 parameters).