Electrical streams

Possible are

• Direct current streams,
• Alternating current streams and
• Three-phase alternating current streams

The type of current NPHAS can be defined in a power-generating component (e.g. 11 or 158) or in a component 1 (or 33).

 

On electric streams the values

• Power Q        
• frequency F       
• voltage U and
• difference between the phase of the voltage and the phase of the current PHEL

are passed on.

 

In order to model electrical networks with branching and merging (resistor network), additional information on electrical streams is required, since in the case of a merge, the phase shift between the currents of the two input streams is also relevant in the case of a branching, the specification of the power distribution is not sufficient to unambiguously determine current strengths and phases on the two output lines.      

In reality, the currents and phases downstream of a branch will adjust due to the resistances or impedances of the two sub-streams.

In the splitter component (component 18) it is possible to calculate this division (see component 18: Regulated branching). During the subsequent merging, a phase-correct addition of the current strengths is then carried out.

To make this possible, information must be forwarded internally on the electrical streams, that is required for calculation by splitting and mixing components. This is

• Real and imaginary part of the resistance in the string: This information is written by the components Component 13: Lines used as electrical resistance (FDN=9) to their input line. For this, component 13 adds its own resistance to the resistance it finds on its output line. In the course of the iteration, the information about the total resistance of the string then ends up at the branch (component 18).
  
• Real and imaginary part of the current I in the string: This information is written to the two output lines by component 18 and passed on from the input to the output by component 13. In the course of the iteration, the information about the current strength in the string ends up at the merge (component 60: controlled merge).

Components 80 (separator) and 81 (line coupling) can also be installed in the stream. They also forward the information.

Note: The forwarding of the real and imaginary parts of the current intensity represents a certain redundancy, since the amount of the current intensity can usually be calculated from power, voltage and phase shift according to I = Q / (U*cos(phi)).
However, by forwarding the real and imaginary parts of the current intensity, pure reactive current (cos(phi) = 0) and the current flow on a voltage-free line (U=0) can also be modelled. The mixer (component 60) then checks the consistency between power and amperage. If there is a discrepancy, the power is given priority (as maintaining the energy balance is considered more important for Ebsilon) and a comment message is issued.

With component 45 (see component 45: value display), the data stored internally on the electrical stream can be displayed (RESULT, RESULT2).

Multiple nested branches and merges cannot be handled by this mechanism. The forwarding of the resistance information always ends at the innermost branch. For modeling more complex networks, however, it is possible to transmit the resistor information to component 18 with a logic line (see component 18: Splitter with ratio specification).

 

Initialization

The usual initial values are

• for frequencies 3000/min and
• for voltages with 1000 V

In particular, too small values for the voltage lead to extremely high values for the current, which causes problems with electrical resistors during the initialization phase.

Especially for the generator (component 11), 3-phase alternating current (three-phase current) is assumed as default. If required, the default value NPHAS can be changed at the generator.