Functional Design of the mCCHP-RES System - Design for Micro-Combined Cooling, Heating and Power Systems - page 277

Actual load
model

Specific load

model

PV
source

P PV

P sl

P al

u p

Electrical

P Se

energy

balance

u St Stirling

engine

P Bi

Electrical
subsystem

P St

P Bo

V

V

Battery

P St u p

Voltage controller

V sp

Fig. 19 Balance of both produced and consumed powers in the electrical subsystem

maintaining the possibility of considering any other plausible values of the
weather conditions and for the temperature values imposed inside the residence.
9. In order to test the system

' s capacity to ensure the comfort requirements, even

cult situations, the analysis of the dynamic performances (in
winter regime, as well as in summer regime), not only the normal meteoro-
logical condition, but the extreme ones must be considered.
10. The control system must include monitoring functions, which can provide
information regarding the quality standards of the mCCHP system.

in the most dif

Figure 19 presents the balance of produced and consumed powers in the elec-
trical subsystem using the control loop for the battery voltage adjusting, V. The
voltage controller, with a setpoint of V sp , modi es the Stirling engine power,

through u St control.
The power delivered into the local electrical grid includes the following
components:

￿ the power supplied by Stirling engine, P Se ;

￿ the power of the PV (photovoltaic system) source, during the interval when it is

active, P PV ; and

the power delivered by the battery, P Bo , when the sum of powers delivered by
the sources mentioned above does not cover the whole consumption.

￿

The electrical load contains the following components:

the useful load of the residence, P al ;

￿