Hello.
How can I model in PSSE an equipment to control the power flow on a particular branch? Lets say I don't want that the power that flows on a branch to be bigger than 10MW, but if from the power flow computation results 5MW this equipment should not change the circulation. If PSSE doesn't support this how can I simulate this situation?
In order to get a load flow case with the P and Q flow between two busses at a particular level, do an iterative process: - run load flow - measure P and Q flow - adjust P and Q for the generator
here is some sample code:
def dispatch_p_and_pf(p_setpoint, pf_setpoint, p_gen_bus, q_gen_bus, Q_from_bus, Q_to_bus, P_from_bus, P_to_bus):
# iteratively adjusts two machines in the load flow case, until the P and Q flows between the meas_bus and poc_bus match the setpoints.
# The machines at which P and Q are adjusted are allowed to be different, for cases where P is set by a generator and Q by a STATCOM
p_sched = p_setpoint
q_sched = default_p_sp *sqrt((1/pf_setpoint)**2 - 1) * np.sign(pf_setpoint)
count = 0
p_gen = p_sched
q_gen = q_sched
print('Perror \tQerror \tPctrl \tQctrl \tPgen \tQgen' )
while count < nbr_solve_iterations:
psspy.machine_chng_2(p_gen_bus,r"""1""",[_i,_i,_i,_i,_i,_i],[ p_gen,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f])
psspy.machine_chng_2(q_gen_bus,r"""1""",[_i,_i,_i,_i,_i,_i],[ _f,q_gen,q_gen,q_gen,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f])
psspy.fdns([0,2,0,0,0,0,99,0])
psspy.fdns([0,2,0,0,0,0,99,0])
ierr, p_control = psspy.brnmsc(P_from_bus, P_to_bus, '1','P')
ierr, q_control = psspy.brnmsc(Q_from_bus, Q_to_bus, '1','Q')
p_error = p_sched - p_control
q_error = q_sched - q_control
if abs(p_error) < error_tol and abs(q_error) < error_tol :
break # the systesm is now set up correctly
p_gen = p_gen + p_error
if p_gen > Pbase:
p_gen = Pbase
q_gen = q_gen + q_error
count +=1
print('%3.2f \t%3.2f \t%3.2f \t%3.2f \t%3.2f \t%3.2f' % (p_error, q_error, p_control, q_control, p_gen, q_gen))
To maintain a flow below a level: - Change the dispatch of nearby generation according to their generation shift factor relative to the branch whenever the branch flow is closed to reach its limit.
On higher power levels (Pflow > 50 MW), to maintain a fix flow on a branch: - Add a phase-shifter transformer in series with the branch. or - Add a HVDC line in series with the branch.
Asked: 2023-08-23 02:47:42 -0500
Seen: 209 times
Last updated: Aug 28 '23
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