DC Generators
DC generators are directly connected to a DC bus, in order to also model ideal voltage sources on the DC side, which can be handy for initialisation of dynamic simulation models.
Parameters
Set of parameters used to model DC branches as defined in the input data
| name | symb. | unit | type | default | definition |
|---|---|---|---|---|---|
| index | $dg$ | - | Int | - | unique index of the generator |
| gen_bus | $e$ | - | Int | - | unique index of the bus to which the generator is connected to |
| pgdcset | $P^{dc,set}_{g}$ | p.u. | Real | - | reference active power generation set point - used as input in power flow calculations |
| pmin | $\underline{P^{dc}_{g}}$ | p.u. | Real | - | minimum stable operating power of the generator |
| pmax | $\overline{P^{dc}_{g}}$ | p.u. | Real | - | maximum power rating of the generator |
| gen_status | $\delta_{dc}$ | - | Int | - | status indicator of the generator |
| mbase | $P_{base}$ | p.u. | Real | - | MW base of the generator |
| vgdc | $V_{g}^{dc,set}$ | p.u. | Real | - | target voltage of generator - used in power flow calculations for constant and droop control modes |
| idle cost | $c_{g,1}$ | Currency / p.u. | Real | - | Generator cost when idle in currency of your choice |
| linear cost | $c_{g,2}$ | Currency / p.u. | Real | - | Generator cost in currency / MW(h) |
| quadratic cost | $c_{g,3}$ | Currency / p.u. | Real | - | Generator cost in currency / (MW(h))^2 |
| idle cost | $c_{g,1}$ | Currency / p.u. | Real | - | Generator cost when idle |
| control_type | $\kappa^{dc}_{g}$ | - | Int | 2 | Used in power flow calculations, 1 = const. power, 2 = const. voltage (slack), 3 = droop |
| droop_const | $k^{dc}_{g}$ | - | Real | - | generator active power droop in MW/V, implemented in pu (MW) / pu (kV) |
Warning: THE UNIT COMMITMENT MODEL IS NOT YET IMPLEMENTED FOR DC GENERATORS!
| name | symb. | unit | type | default | definition |
|---|---|---|---|---|---|
| mut | $mut_{g}$ | - | Int | - | minimum up time for generator used in unit commitment problems, expressed as a multiple of the UC time step |
| mdt | $mdt_{g}$ | - | Int | - | minimum down time for generator used in unit commitment problems, expressed as a multiple of the UC time step |
| ramp_rate | $\Lambda_{g}$ | p.u. / time step | Real | - | ramp rate of the generator used in UC problem |
| ramprateper_s | $\Lambda_{g}^{s}$ | p.u. / s | Real | - | ramp rate of the generator used in frequency constrained UC problem |
| inertia_constant | $H_{g}$ | s | Real | - | inertia constant of the generator used in frequency constrained UC problem |
| fcr_contribution | $\delta_{g}^{fcr}$ | - | Int | - | Indicator if generator g participates in providing frequency containtment reserves |
| area | $a_{g}$ | - | Int | - | Area in which the generator is located, used for tie line contingencies in frequency constrained UC problem |
| zone | $z_{g}$ | - | Int | - | Zone in which the generator is located, used for loss of infeed contingencies in frequency constrained UC problem |
| model | $m_{g}$ | - | Int | - | Generator cost model, 1 = piecewise linear, 2 = polynomial (matpower style) |
| ncost | $n_{g}$ | - | Int | - | Number of polynomial coefficients for generator costs |
| startup | $c_{g}^{suc}$ | Currency | Real | - | Start-up cost in the currency of your choice |
| shutdown | $c_{c}^{sdc}$ | Currency | Real | - | Shut-down cost in the currency of your choice |
| res | $res_{g}$ | - | Int | - | True / false indicator for RES generators |
Variables
Optimisation variables representing DC generator behaviour
| name | symb. | unit | formulation | definition |
|---|---|---|---|---|
| pgdc | $P^{dc}_{g}$ | p.u. | ACP, ACR, LPAC, SOC, DCP, NF | Active power set point of generator g |
Not yet defined for IVR!
Constraints
Active power limits
\[\begin{align} \underline{P^{dc}_{g}} &\leq P^{dc}_{g} \leq \overline{P^{dc}_{g}} \\ \end{align}\]
Generator control mode: used in power flow
\[\begin{align} if~~~~\kappa^{dc}_{g} = 1:& \\ P^{dc}_{g} &= P^{dc,set}_{g} \\ if~~~~\kappa^{dc}_{g} = 2:& \\ vdc_{e} &= V_{g}^{dc,set} \\ if~~~~\kappa^{dc}_{g} = 3:& \\ P^{dc}_{g} &= P^{dc,set}_{g} - 1 / k^{dc}_{g} * (vdc_{e} - V_{g}^{dc,set}) \end{align}\]