Hi all, I would like to model constant impedance and constant current loads in Matpower. With some help of the manual and Ray Zimmerman I managed to change the newtonpf.m file as follows:
mis = V .* conj(Ybus * V) - Sbus .* (V.^n); (line 74) mis = V .* conj(Ybus * V) - Sbus .* (V.^n); (line 124) with n = 0 for constant power, n =1 for constant current and n = 2 for constant impedance. However, this affects the Jacobian therefore I must edit dSbus_dV.m as well. In my attempt to do this I am stuck since I do not know how to do this properly. I know, from TN2-OPF-Derivatives.pdf, that: I_load = [Y_load] V - see (22) and (23) S_load = [V] I_load* - see (27) - (32) Where [Yload] = [conj(Sd)]. This leads to g(x) = Sbus + Sd - Cg Sg. With Sbus = [V] Ibus* and Sd = [V] Iload*. For the partial derivatives of the Jacobian dSbus_dVm and dSbus_dVa I found: dSbus_dVm = diagV * conj(Ybus * diagVnorm) + conj(diagIbus) * diagVnorm + diagV * conj(Yload * diagVnorm) + conj(diagIload) * diagVnorm; dSbus_dVa = 1j * diagV * conj(diagIbus - Ybus * diagV) + 1j * diagV * conj(diagIload - Yload * diagV); Are these two equations for the partial derivatives correct? Any help would be appreciated. Thanks in advance. Regards, Jip
