user manual

Functions

Below we provide a description of the predefined functions that can be used in the formulas.

Table: Functions, which can be used in formulas

SQR	Square For example, SQR(4) returns the value 16.
SIN	Sine in radians For example, SIN(1.571) returns the value 1.
COS	Cosine, see also SIN
TAN	Tangent, see also SIN
SINH	Hyperbolic sine, see also SIN
COSH	Hyperbolic cosine, see also SIN
ATAN	Arctangent, see also SIN
COTAN	Cotangent, see also SIN
EXP	Exponential function For example, EXP(1) returns the value 2.718.
LN	Natural logarithm For example, LN(4) returns the value 1.386.
LOG	Decadic logarithm For example, LOG(10) returns the value 1.
SQRT	Square root For example, SQRT(4) returns the value 2.
ABS	Absolute value For example, ABS(-4) returns the value 4.
SIGN	Sign, returns -1 for negative, 1 for positive and 0 for 0 For example, SIGN (-4) returns the value -1.
TRUNC	Integer part For example, TRUNC(-3.7) returns the value -3.
CEIL	Round up to the next higher integer For example, CEIL(-3.7) returns the value -3.
FLOOR	Round down to the next lower integer For example, FLOOR(-3.7) returns the value -4.
RND	Integer random number The upper limit of the random number should be specified as an argument.
RANDOM	Random number with decimal places The lower limit of the random number should be specified as an argument.
MIN	Minimum value For example, MIN(2, 3) returns the value 2.
MAX	Maximum value For example, MAX(2, 3) returns the value 3.
IF	If (condition, return value for condition complied with, return value for condition non complied with). If the condition is complied with, the first return value will be returned as a result, otherwise the second. Operations too may be used as a return value; depending on the condition, only the appropriate return value will be evaluated. Several IF functions may be nested in one another. For example, IF(1>2, 3, 4) returns the value 4.
SUM	Sum of any number of arguments. For example, SUM(1, 2, 3) returns the value 6.
MATCHFLOW (\(T_{i}\), \(Q\), \(T_{a}\), \(C_{p}\), \({\dot{V}}_{\min}\), \({\dot{V}}_{\max}\))	Regulation of a flow-rate in l/to the desired temperature MATCHFLOW( \(T_{i}\) Inlet temperature in °C, for example to the collector, \(Q\) Power in W, for example power of the collector,  \(T_{a}\) Outlet temperature in °C, for example the desired target temperature, \(C_{p}\) Heat capacity in J/(l*K), for example, the heat capacity of the fluid, \({\dot{V}}_{\min}\) min. flow-rate in l/h, for example the lower limit of the pump, \({\dot{V}}_{\max}\) max. flow-rate in l/h, for example the upper limit of the pump) \(\dot{V} = \dot{\frac{Q}{C_{p}*\left( T_{a} – T_{i} \right)}}*3600\)
MATCHPOWER (\(T_{i}\), \(\dot{V}\), \(T_{a}\), \(C_{p}\), \({\dot{Q}}_{\min}\), \({\dot{Q}}_{\max}\))	Regulation of a flow-rate in W to the desired temperature MATCHPOWER( \(T_{i}\) Inlet temperature in °C, for example to the boiler \(\dot{V}\) Flow-rate in l/h, for example, flow-rate of the boiler pump, \(T_{a}\) Outlet temperature in °C, for example the desired target temperature, \(C_{p}\) Heat capacity in J/(l*K), for example, the heat capacity of the fluid, \({\dot{Q}}_{\min}\) min. power in W, for example the lower limit of the boiler pump, \({\dot{Q}}_{\max}\) max. power in W, for example, the upper limit of the boiler pump) \(\dot{Q} = \left( T_{a} – T_{i} \right)*C_{p}*\dot{V}/3600\) If Qmin / Qmax 0 the values will not be taken into account; otherwise, the  result Q will be restricted to these minimum/maximum values before being returned.
MATCHRATE (\(T_{u}\), \(T_{l}\), \(T_{o}\))	Regulation of a mixing ratio to the desired temperature MATCHRATE( \(T_{u}\) Upper level temperature in °C, for example hot water inlet to mixing valve, \(T_{l}\) Lower level temperature in °C, for example cold water inlet to mixing valve, \(T_{o}\) Outlet temperature in °C, for example the desired target temperature) \(p = \frac{T_{u} – T_{o}}{T_{u} – T_{l}}\)
MEANVALUE (\(a\), \(b\))	Arithmetic mean value of two values MEANVALUE ( \(a\) value 1, for example a temperature value from the latest time step \(b\) value 2, for example a temperature value from the current time step) \(m = \frac{a + b}{2}\)
HEATINGCURVE(Tsoll, Ta_norm, a, Ta)	Regulation of temperature based on the heating curve  (function HEATINGCURVE) The function adopts 4 parameters: Tsoll: nominal inlet temperature heating elements  (= max VL in the chart)  [°C] Ta_norm: design outdoor temperature (for the Tsoll gilt (= -14°C in the chart)[°C] a: heating curve gradient Ta: current outdoor temperature [°C] The point (= 20°C in the chart) where the curve meets the x-axis is determined from the remaining parameters.
PVPROG (\(t,\ P_{pv}, \ P_{ld},\ p_{gfl},\ P_{gsl},\), \(t_{fpast}, \ t_{fhor}, \ \mathrm{\Delta}t_{freq}, \ \mathrm{\Delta}t_{f})\))	Forecast-based battery control with measurement-based PV- and consumption forecasts. PVPROG (\(t\ \) current simulation time in s, \(P_{pv}\) PV production AC (before curtailment) in W, \(P_{ld}\) electricity consumption in W, \(p_{gfl}\) Feed-in limit normalised to the installed nominal PV capacity (0 to deactivate dynamic feed-in limitation through the battery), \(P_{gsl}\ \) grid supply limit for the electricity consumption in W (0 to deactivate grid supply limitation), \(t_{fpast}\ \) time frame in h in which the weather situation is incorporated into the PV forecasts, \(t_{fhor}\ \) forecast horizon of the PV and load forecasts in h, \(\mathrm{\Delta}t_{freq}\ \) freqency of the forecast updates in min [1 (recommended) or 15 (for a faster simulation but with a slightly reduced control accuracy and therefore with decreased system performance] – The recommended value is used without warning for unexpected inputs, \(\mathrm{\Delta}t_{f}\ \) temporal resolution of the PV- and load forecasts [1 or 15 (recommended)] – The recommended value is used without warning for unexpected inputs)