From 06bccb6543deb3ca498d43ba7dd077e7b918cabe Mon Sep 17 00:00:00 2001
From: Clair Mould <86794332+clmould@users.noreply.github.com>
Date: Mon, 18 May 2026 12:13:10 +0100
Subject: [PATCH] convert pf power vars to dataclass

---
 process/core/init.py                         |   2 -
 process/core/input.py                        |   8 +-
 process/core/model.py                        |   2 +
 process/core/solver/constraints.py           |   6 +-
 process/core/solver/objectives.py            |   3 +-
 process/data_structure/pf_power_variables.py | 120 ++++++++-----------
 process/models/costs/costs.py                |  21 ++--
 process/models/costs/costs_2015.py           |   3 +-
 process/models/power.py                      |  65 +++++-----
 process/models/pulse.py                      |   3 +-
 tests/unit/models/test_costs_1990.py         |  13 +-
 tests/unit/models/test_costs_2015.py         |   3 +-
 tests/unit/models/test_power.py              |  43 ++++---
 tests/unit/models/test_pulse.py              |   3 +-
 14 files changed, 130 insertions(+), 165 deletions(-)

diff --git a/process/core/init.py b/process/core/init.py
index 348267f1b..badd1c714 100644
--- a/process/core/init.py
+++ b/process/core/init.py
@@ -20,7 +20,6 @@
     init_impurity_radiation_module,
 )
 from process.data_structure.neoclassics_variables import init_neoclassics_variables
-from process.data_structure.pf_power_variables import init_pf_power_variables
 from process.data_structure.physics_variables import (
     init_physics_module,
     init_physics_variables,
@@ -250,7 +249,6 @@ def init_all_module_vars():
     init_superconducting_tf_coil_variables()
     init_tfcoil_variables()
     constants.init_constants()
-    init_pf_power_variables()
     init_rebco_variables()
     init_neoclassics_variables()
 
diff --git a/process/core/input.py b/process/core/input.py
index 1605ce419..565a13087 100644
--- a/process/core/input.py
+++ b/process/core/input.py
@@ -668,9 +668,7 @@ def __post_init__(self):
     "max_vv_stress": InputVariable(
         data_structure.tfcoil_variables, float, range=(100000.0, 500000000.0)
     ),
-    "maxpoloidalpower": InputVariable(
-        data_structure.pf_power_variables, float, range=(0.0, 2000.0)
-    ),
+    "maxpoloidalpower": InputVariable("pf_power", float, range=(0.0, 2000.0)),
     "pflux_fw_rad_max": InputVariable("constraints", float, range=(0.1, 10.0)),
     "mbvfac": InputVariable("buildings", float, range=(0.9, 3.0)),
     "mcdriv": InputVariable("ife", float, range=(0.1, 10.0)),
@@ -1266,9 +1264,7 @@ def __post_init__(self):
     "ireactor": InputVariable("costs", int, choices=[0, 1]),
     "irefprop": InputVariable("fwbs", int, choices=[0, 1]),
     "i_hcd_calculations": InputVariable("current_drive", int, choices=[0, 1]),
-    "i_pf_energy_storage_source": InputVariable(
-        data_structure.pf_power_variables, int, range=(1, 3)
-    ),
+    "i_pf_energy_storage_source": InputVariable("pf_power", int, range=(1, 3)),
     "istell": InputVariable("stellarator", int, range=(0, 6)),
     "isthtr": InputVariable("stellarator", int, range=(1, 3)),
     "istore": InputVariable("pulse", int, range=(1, 3)),
diff --git a/process/core/model.py b/process/core/model.py
index 1f7b03db9..37ae1e4e9 100644
--- a/process/core/model.py
+++ b/process/core/model.py
@@ -16,6 +16,7 @@
 from process.data_structure.fwbs_variables import FWBSData
 from process.data_structure.heat_transport_variables import HeatTransportData
 from process.data_structure.ife_variables import IFEData
+from process.data_structure.pf_power_variables import PFPowerData
 from process.data_structure.pfcoil_variables import PFCoilData
 from process.data_structure.power_variables import PowerData
 from process.data_structure.primary_pumping_variables import PrimaryPumpingData
@@ -59,6 +60,7 @@ class DataStructure:
     power: PowerData = initialise_later
     stellarator: StellaratorData = initialise_later
     stellarator_config: StellaratorConfigData = initialise_later
+    pf_power: PFPowerData = initialise_later
 
     def __post_init__(self):
         for f in fields(self):
diff --git a/process/core/solver/constraints.py b/process/core/solver/constraints.py
index 3b3ca07df..201d3a0c8 100644
--- a/process/core/solver/constraints.py
+++ b/process/core/solver/constraints.py
@@ -1376,15 +1376,15 @@ def constraint_equation_65(constraint_registration, _data):
 
 
 @ConstraintManager.register_constraint(66, "MW", "<=")
-def constrain_equation_66(constraint_registration, _data):
+def constrain_equation_66(constraint_registration, data):
     """Upper limit on rate of change of energy in poloidal field
 
     maxpoloidalpower: Maximum permitted absolute rate of change of stored energy in poloidal field (MW)
     peakpoloidalpower: Peak absolute rate of change of stored energy in poloidal field (MW) (11/01/16)
     """
     return leq(
-        data_structure.pf_power_variables.peakpoloidalpower,
-        data_structure.pf_power_variables.maxpoloidalpower,
+        data.pf_power.peakpoloidalpower,
+        data.pf_power.maxpoloidalpower,
         constraint_registration,
     )
 
diff --git a/process/core/solver/objectives.py b/process/core/solver/objectives.py
index ce3532890..716607e44 100644
--- a/process/core/solver/objectives.py
+++ b/process/core/solver/objectives.py
@@ -3,7 +3,6 @@
 from process.core.exceptions import ProcessValueError
 from process.core.model import DataStructure
 from process.data_structure import (
-    pf_power_variables,
     physics_variables,
     tfcoil_variables,
 )
@@ -70,7 +69,7 @@ def objective_function(minmax: int, data: DataStructure) -> float:
             objective_metric = physics_variables.pflux_fw_neutron_mw
         case 4:
             objective_metric = (
-                tfcoil_variables.tfcmw + 1e-3 * pf_power_variables.srcktpm
+                tfcoil_variables.tfcmw + 1e-3 * data.pf_power.srcktpm
             ) / 10.0
         case 5:
             objective_metric = physics_variables.p_fusion_total_mw / (
diff --git a/process/data_structure/pf_power_variables.py b/process/data_structure/pf_power_variables.py
index ae398ff10..fff22c041 100644
--- a/process/data_structure/pf_power_variables.py
+++ b/process/data_structure/pf_power_variables.py
@@ -2,80 +2,56 @@
 Module containing global variables relating to the PF coil power conversion system
 """
 
+from dataclasses import dataclass, field
+
 import numpy as np
 
-acptmax: float = None
-"""average of currents in PF circuits (kA)"""
 
-ensxpfm: float = None
-"""maximum stored energy in the PF circuits (MJ)"""
+@dataclass
+class PFPowerData:
+    acptmax: float = 0.0
+    """average of currents in PF circuits (kA)"""
+
+    ensxpfm: float = 0.0
+    """maximum stored energy in the PF circuits (MJ)"""
+
+    i_pf_energy_storage_source: int = 2
+    """Switch for PF coil energy storage option:
+    - =1 all power from MGF (motor-generator flywheel) units
+    - =2 all pulsed power from line
+    - =3 PF power from MGF, heating from line
+    (In fact, options 1 and 3 are not treated differently)
+    """
+
+    pfckts: float = 0.0
+    """number of PF coil circuits"""
+
+    spfbusl: float = 0.0
+    """total PF coil circuit bus length (m)"""
+
+    spsmva: float = 0.0
+    """sum of PF power supply ratings (MVA)"""
+
+    srcktpm: float = 0.0
+    """sum of resistive PF coil power (kW)"""
+
+    vpfskv: float = 0.0
+    """PF coil voltage (kV)"""
+
+    peakpoloidalpower: float = 0.0
+    """Peak absolute rate of change of stored energy in poloidal field (MW)"""
+
+    maxpoloidalpower: float = 1000.0
+    """Maximum permitted absolute rate of change of stored energy in poloidal field (MW)"""
+
+    poloidalpower: list[float] = field(default_factory=lambda: np.zeros(5))
+    """Poloidal power usage at time t (MW)"""
+
+    f_p_pf_energy_store_loss: float = 0.1
+    """Fraction of PF magnetic energy moved into/out of storage that is lost each time"""
+
+    f_p_pf_psu_loss: float = 0.1
+    """Fraction of inductive power flow lost in the PF power supplies/converters."""
 
-i_pf_energy_storage_source: int = None
-"""Switch for PF coil energy storage option:
- - =1 all power from MGF (motor-generator flywheel) units
- - =2 all pulsed power from line
- - =3 PF power from MGF, heating from line
-   (In fact, options 1 and 3 are not treated differently)
-"""
 
-pfckts: float = None
-"""number of PF coil circuits"""
-
-spfbusl: float = None
-"""total PF coil circuit bus length (m)"""
-
-spsmva: float = None
-"""sum of PF power supply ratings (MVA)"""
-
-srcktpm: float = None
-"""sum of resistive PF coil power (kW)"""
-
-vpfskv: float = None
-"""PF coil voltage (kV)"""
-
-peakpoloidalpower: float = None
-"""Peak absolute rate of change of stored energy in poloidal field (MW)"""
-
-maxpoloidalpower: float = None
-"""Maximum permitted absolute rate of change of stored energy in poloidal field (MW)"""
-
-poloidalpower: list[float] = None
-"""Poloidal power usage at time t (MW)"""
-
-f_p_pf_energy_store_loss: float = None
-"""Fraction of PF magnetic energy moved into/out of storage that is lost each time"""
-
-f_p_pf_psu_loss: float = None
-"""Fraction of inductive power flow lost in the PF power supplies/converters."""
-
-
-def init_pf_power_variables():
-    """Initialise PF coil power variables"""
-    global \
-        acptmax, \
-        ensxpfm, \
-        i_pf_energy_storage_source, \
-        pfckts, \
-        spfbusl, \
-        spsmva, \
-        srcktpm, \
-        vpfskv, \
-        peakpoloidalpower, \
-        maxpoloidalpower, \
-        poloidalpower, \
-        f_p_pf_energy_store_loss, \
-        f_p_pf_psu_loss
-
-    acptmax = 0.0
-    ensxpfm = 0.0
-    i_pf_energy_storage_source = 2
-    pfckts = 0.0
-    spfbusl = 0.0
-    spsmva = 0.0
-    srcktpm = 0.0
-    vpfskv = 0.0
-    peakpoloidalpower = 0.0
-    maxpoloidalpower = 1000.0
-    poloidalpower = np.zeros(5)
-    f_p_pf_energy_store_loss = 0.1
-    f_p_pf_psu_loss = 0.1
+CREATE_DICTS_FROM_DATACLASS = PFPowerData
diff --git a/process/models/costs/costs.py b/process/models/costs/costs.py
index 521ee7f6e..bc68a495e 100644
--- a/process/models/costs/costs.py
+++ b/process/models/costs/costs.py
@@ -7,7 +7,6 @@
 from process.core.exceptions import ProcessValueError
 from process.core.model import Model
 from process.data_structure import (
-    pf_power_variables,
     physics_variables,
     tfcoil_variables,
 )
@@ -2132,7 +2131,7 @@ def acc2252(self):
         #  Account 225.2.2 : PF coil instrumentation and control
 
         self.data.costs.c22522 = (
-            1.0e-6 * self.data.costs.ucpfic * pf_power_variables.pfckts * 30.0e0
+            1.0e-6 * self.data.costs.ucpfic * self.data.pf_power.pfckts * 30.0e0
         )
         self.data.costs.c22522 = self.data.costs.fkind * self.data.costs.c22522
 
@@ -2141,19 +2140,19 @@ def acc2252(self):
         self.data.costs.c22523 = (
             1.0e-6
             * self.data.costs.ucpfb
-            * pf_power_variables.spfbusl
-            * pf_power_variables.acptmax
+            * self.data.pf_power.spfbusl
+            * self.data.pf_power.acptmax
         )
         self.data.costs.c22523 = self.data.costs.fkind * self.data.costs.c22523
 
         #  Account 225.2.4 : PF coil burn power supplies
 
-        if pf_power_variables.pfckts != 0.0e0:  # noqa: RUF069
+        if self.data.pf_power.pfckts != 0.0e0:  # noqa: RUF069
             self.data.costs.c22524 = (
                 1.0e-6
                 * self.data.costs.ucpfbs
-                * pf_power_variables.pfckts
-                * (pf_power_variables.srcktpm / pf_power_variables.pfckts) ** 0.7e0
+                * self.data.pf_power.pfckts
+                * (self.data.pf_power.srcktpm / self.data.pf_power.pfckts) ** 0.7e0
             )
         else:
             self.data.costs.c22524 = 0.0e0
@@ -2165,22 +2164,22 @@ def acc2252(self):
         self.data.costs.c22525 = (
             1.0e-6
             * self.data.costs.ucpfbk
-            * pf_power_variables.pfckts
-            * (pf_power_variables.acptmax * pf_power_variables.vpfskv) ** 0.7e0
+            * self.data.pf_power.pfckts
+            * (self.data.pf_power.acptmax * self.data.pf_power.vpfskv) ** 0.7e0
         )
         self.data.costs.c22525 = self.data.costs.fkind * self.data.costs.c22525
 
         #  Account 225.2.6 : PF coil dump resistors
 
         self.data.costs.c22526 = (
-            1.0e-6 * self.data.costs.ucpfdr1 * pf_power_variables.ensxpfm
+            1.0e-6 * self.data.costs.ucpfdr1 * self.data.pf_power.ensxpfm
         )
         self.data.costs.c22526 = self.data.costs.fkind * self.data.costs.c22526
 
         #  Account 225.2.7 : PF coil AC breakers
 
         self.data.costs.c22527 = (
-            1.0e-6 * self.data.costs.ucpfcb * pf_power_variables.pfckts
+            1.0e-6 * self.data.costs.ucpfcb * self.data.pf_power.pfckts
         )
         self.data.costs.c22527 = self.data.costs.fkind * self.data.costs.c22527
 
diff --git a/process/models/costs/costs_2015.py b/process/models/costs/costs_2015.py
index be133393e..5ad234e4e 100644
--- a/process/models/costs/costs_2015.py
+++ b/process/models/costs/costs_2015.py
@@ -7,7 +7,6 @@
 from process.core.model import Model
 from process.data_structure import (
     global_variables,
-    pf_power_variables,
     physics_variables,
     tfcoil_variables,
 )
@@ -1087,7 +1086,7 @@ def calc_remaining_subsystems(self):
         #  For ITER value see
         #  K:\Power Plant Physics and Technology\PROCESS\PROCESS documentation papers\resistive diffusion time.xmcd or pdf
         self.data.costs_2015.s_k[51] = (
-            pf_power_variables.ensxpfm * 1.0e6 / physics_variables.t_plasma_res_diffusion
+            self.data.pf_power.ensxpfm * 1.0e6 / physics_variables.t_plasma_res_diffusion
         )
         self.data.costs_2015.s_kref[51] = 8.0e9 / 953.0e0
         self.data.costs_2015.s_cost[51] = (
diff --git a/process/models/power.py b/process/models/power.py
index 803907f0d..a81f0c06f 100644
--- a/process/models/power.py
+++ b/process/models/power.py
@@ -13,7 +13,6 @@
 from process.core.model import Model
 from process.data_structure import (
     numerics,
-    pf_power_variables,
     physics_variables,
     tfcoil_variables,
 )
@@ -109,6 +108,7 @@ def _pf_loss_power_supply_j(
         n_pf_cs_plasma_circuits: int,
         c_pf_coil_turn: np.ndarray,
         ind_pf_cs_plasma_mutual: np.ndarray,
+        f_p_pf_psu_loss: float,
     ) -> float:
         """
         Power supply conversion loss over interval idx_time_interval
@@ -126,6 +126,8 @@ def _pf_loss_power_supply_j(
             PF circuit current per turn at pulse times [A]
         ind_pf_cs_plasma_mutual : np.ndarray
             mutual inductance matrix between PF circuits [H]
+        f_p_pf_psu_loss: float
+            Fraction of inductive power flow lost in the PF power supplies/converters
 
         Returns
         -------
@@ -151,9 +153,7 @@ def _pf_loss_power_supply_j(
                 )
 
             e_loss_pf_psu_j += (
-                0.5e0
-                * pf_power_variables.f_p_pf_psu_loss
-                * abs(c_pf_sum_a * delta_flux_linkage_wb)
+                0.5e0 * f_p_pf_psu_loss * abs(c_pf_sum_a * delta_flux_linkage_wb)
             )
 
         return e_loss_pf_psu_j
@@ -267,6 +267,7 @@ def _pf_loss_interval_total_j(
             n_pf_cs_plasma_circuits=n_pf_cs_plasma_circuits,
             c_pf_coil_turn=c_pf_coil_turn,
             ind_pf_cs_plasma_mutual=ind_pf_cs_plasma_mutual,
+            f_p_pf_psu_loss=self.data.pf_power.f_p_pf_psu_loss,
         )
 
         e_loss_pf_bus_j = self._pf_loss_busbar_j(
@@ -300,7 +301,7 @@ def pfpwr(self, output: bool):
         c_pf_coil_turn = self.data.pf_coil.c_pf_coil_turn  # [A]
         ind_pf_cs_plasma_mutual = self.data.pf_coil.ind_pf_cs_plasma_mutual  # [H]
         f_p_pf_energy_store_loss = (
-            pf_power_variables.f_p_pf_energy_store_loss
+            self.data.pf_power.f_p_pf_energy_store_loss
         )  # [unitless]
         n_pf_cs_plasma_circuits = self.data.pf_coil.n_pf_cs_plasma_circuits  # [unitless]
 
@@ -333,7 +334,7 @@ def pfpwr(self, output: bool):
         # Map PF group to representative circuit index (used for busbar I^2R per circuit)
         pf_group_circuit_index = np.zeros((n_pf_coil_groups,), dtype=int)
 
-        pf_power_variables.srcktpm = 0.0e0
+        self.data.pf_power.srcktpm = 0.0e0
         pfbuspwr = 0.0e0
 
         for a_pf_bus_cm in range(n_pf_coil_groups):
@@ -392,7 +393,7 @@ def pfpwr(self, output: bool):
 
             #  Compute the sum of resistive power in the PF circuits, kW
             pfbuspwr += 1.0e-3 * res_pf_bus[a_pf_bus_cm] * cptburn**2
-            pf_power_variables.srcktpm += (
+            self.data.pf_power.srcktpm += (
                 1.0e3 * p_pf_circuit_resistive_peak[a_pf_bus_cm]
             )
 
@@ -490,7 +491,7 @@ def pfpwr(self, output: bool):
                 )
                 > 1.0e0
             ):
-                pf_power_variables.poloidalpower[idx_time_interval] = (
+                self.data.pf_power.poloidalpower[idx_time_interval] = (
                     poloidalenergy[idx_time_interval + 1]
                     - poloidalenergy[idx_time_interval]
                 ) / (
@@ -499,7 +500,7 @@ def pfpwr(self, output: bool):
                 )
             else:
                 # Flag when an interval is small or zero MDK 30/11/16
-                pf_power_variables.poloidalpower[idx_time_interval] = 9.9e9
+                self.data.pf_power.poloidalpower[idx_time_interval] = 9.9e9
 
             dt_pulse_phase_s = (
                 t_pulse_cumulative[idx_time_interval + 1]
@@ -536,22 +537,22 @@ def pfpwr(self, output: bool):
         #  Compute the maximum stored energy and the maximum dissipative
         #  energy in all the PF circuits over the entire cycle time, MJ
         # ensxpfm = 1.0e-6 * ensxpf
-        pf_power_variables.ensxpfm = 1.0e-6 * max(poloidalenergy)
+        self.data.pf_power.ensxpfm = 1.0e-6 * max(poloidalenergy)
         # Peak absolute rate of change of stored energy in poloidal field (MW)
-        pf_power_variables.peakpoloidalpower = (
-            max(abs(pf_power_variables.poloidalpower)) / 1.0e6
+        self.data.pf_power.peakpoloidalpower = (
+            max(abs(self.data.pf_power.poloidalpower)) / 1.0e6
         )
 
         #  Maximum total MVA requirements
         self.data.heat_transport.peakmva = max((powpfr + powpfi), powpfr2)
 
-        pf_power_variables.vpfskv = 20.0e0
-        pf_power_variables.pfckts = (
+        self.data.pf_power.vpfskv = 20.0e0
+        self.data.pf_power.pfckts = (
             self.data.pf_coil.n_pf_cs_plasma_circuits - 2
         ) + 6.0e0
-        pf_power_variables.spfbusl = pfbusl * pf_power_variables.pfckts
-        pf_power_variables.acptmax = 0.0e0
-        pf_power_variables.spsmva = 0.0e0
+        self.data.pf_power.spfbusl = pfbusl * self.data.pf_power.pfckts
+        self.data.pf_power.acptmax = 0.0e0
+        self.data.pf_power.spsmva = 0.0e0
 
         for idx_circuit in range(self.data.pf_coil.n_pf_cs_plasma_circuits - 1):
             #  Power supply MVA for each PF circuit
@@ -561,13 +562,13 @@ def pfpwr(self, output: bool):
             )
 
             #  Sum of the power supply MVA of the PF circuits
-            pf_power_variables.spsmva += psmva[idx_circuit]
+            self.data.pf_power.spsmva += psmva[idx_circuit]
 
             #  Average of the maximum currents in the PF circuits, kA
-            pf_power_variables.acptmax += (
+            self.data.pf_power.acptmax += (
                 1.0e-3
                 * abs(self.data.pf_coil.c_pf_coil_turn_peak_input[idx_circuit])
-                / pf_power_variables.pfckts
+                / self.data.pf_power.pfckts
             )
 
         #  PF wall plug power dissipated in power supply for ohmic heating (MW)
@@ -589,20 +590,20 @@ def pfpwr(self, output: bool):
             self.outfile,
             "Number of PF coil circuits",
             "(pfckts)",
-            pf_power_variables.pfckts,
+            self.data.pf_power.pfckts,
         )
         po.ovarre(
             self.outfile,
             "Sum of PF power supply ratings (MVA)",
             "(spsmva)",
-            pf_power_variables.spsmva,
+            self.data.pf_power.spsmva,
             "OP ",
         )
         po.ovarre(
             self.outfile,
             "Total PF coil circuit bus length (m)",
             "(spfbusl)",
-            pf_power_variables.spfbusl,
+            self.data.pf_power.spfbusl,
             "OP ",
         )
         po.ovarre(
@@ -616,14 +617,14 @@ def pfpwr(self, output: bool):
             self.outfile,
             "Total PF coil resistive power (kW)",
             "(srcktpm)",
-            pf_power_variables.srcktpm,
+            self.data.pf_power.srcktpm,
             "OP ",
         )
         po.ovarre(
             self.outfile,
             "Maximum PF coil voltage (kV)",
             "(vpfskv)",
-            pf_power_variables.vpfskv,
+            self.data.pf_power.vpfskv,
         )
         po.ovarre(
             self.outfile,
@@ -641,14 +642,14 @@ def pfpwr(self, output: bool):
             self.outfile,
             "Maximum stored energy in poloidal field (MJ)",
             "(ensxpfm)",
-            pf_power_variables.ensxpfm,
+            self.data.pf_power.ensxpfm,
             "OP ",
         )
         po.ovarre(
             self.outfile,
             "Peak absolute rate of change of stored energy in poloidal field (MW)",
             "(peakpoloidalpower)",
-            pf_power_variables.peakpoloidalpower,
+            self.data.pf_power.peakpoloidalpower,
             "OP ",
         )
 
@@ -658,7 +659,7 @@ def pfpwr(self, output: bool):
                 "Max permitted abs rate of change of stored energy in poloidal "
                 "field (MW)",
                 "maxpoloidalpower",
-                pf_power_variables.maxpoloidalpower,
+                self.data.pf_power.maxpoloidalpower,
             )
 
         if any(poloidalenergy < 0.0e0):
@@ -686,8 +687,8 @@ def acpow(self, output: bool):
 
         """
         ptfmw = self.data.heat_transport.p_tf_electric_supplies_mw
-        ppfmw = 1.0e-3 * pf_power_variables.srcktpm
-        if pf_power_variables.i_pf_energy_storage_source == 2:
+        ppfmw = 1.0e-3 * self.data.pf_power.srcktpm
+        if self.data.pf_power.i_pf_energy_storage_source == 2:
             ppfmw += self.data.heat_transport.peakmva
 
         #  Power to plasma heating supplies, MW
@@ -715,7 +716,7 @@ def acpow(self, output: bool):
 
         #  Add contribution from motor-generator flywheels if these are part of
         #  the PF coil energy storage system
-        if pf_power_variables.i_pf_energy_storage_source != 2:
+        if self.data.pf_power.i_pf_energy_storage_source != 2:
             self.data.heat_transport.pacpmw += self.data.heat_transport.fmgdmw
 
         # Estimate of the total low voltage power, MW
@@ -1036,7 +1037,7 @@ def calculate_cryo_loads(self):
                 tfcoil_variables.tfcryoarea,
                 self.data.structure.coldmass,
                 self.data.fwbs.p_tf_nuclear_heat_mw,
-                pf_power_variables.ensxpfm,
+                self.data.pf_power.ensxpfm,
                 self.data.times.t_plant_pulse_plasma_present,
                 tfcoil_variables.c_tf_turn,
                 tfcoil_variables.n_tf_coils,
diff --git a/process/models/pulse.py b/process/models/pulse.py
index 184e946f1..3adda0014 100644
--- a/process/models/pulse.py
+++ b/process/models/pulse.py
@@ -7,7 +7,6 @@
 from process.core.model import Model
 from process.data_structure import (
     numerics,
-    pf_power_variables,
     physics_variables,
 )
 
@@ -106,7 +105,7 @@ def tohswg(self, output: bool):
 
         #  Central Solenoid power source emf (volts)
 
-        v = pf_power_variables.vpfskv * 1.0e3
+        v = self.data.pf_power.vpfskv * 1.0e3
 
         #  Mutual inductance between Central Solenoid and plasma (H)
 
diff --git a/tests/unit/models/test_costs_1990.py b/tests/unit/models/test_costs_1990.py
index 452265d2e..164c7c414 100644
--- a/tests/unit/models/test_costs_1990.py
+++ b/tests/unit/models/test_costs_1990.py
@@ -7,7 +7,6 @@
 
 from process import data_structure
 from process.data_structure import (
-    pf_power_variables,
     physics_variables,
     tfcoil_variables,
 )
@@ -3649,17 +3648,17 @@ def test_acc2252(acc2252param, monkeypatch, costs):
 
     monkeypatch.setattr(costs.data.heat_transport, "peakmva", acc2252param.peakmva)
 
-    monkeypatch.setattr(pf_power_variables, "ensxpfm", acc2252param.ensxpfm)
+    monkeypatch.setattr(costs.data.pf_power, "ensxpfm", acc2252param.ensxpfm)
 
-    monkeypatch.setattr(pf_power_variables, "spfbusl", acc2252param.spfbusl)
+    monkeypatch.setattr(costs.data.pf_power, "spfbusl", acc2252param.spfbusl)
 
-    monkeypatch.setattr(pf_power_variables, "pfckts", acc2252param.pfckts)
+    monkeypatch.setattr(costs.data.pf_power, "pfckts", acc2252param.pfckts)
 
-    monkeypatch.setattr(pf_power_variables, "srcktpm", acc2252param.srcktpm)
+    monkeypatch.setattr(costs.data.pf_power, "srcktpm", acc2252param.srcktpm)
 
-    monkeypatch.setattr(pf_power_variables, "vpfskv", acc2252param.vpfskv)
+    monkeypatch.setattr(costs.data.pf_power, "vpfskv", acc2252param.vpfskv)
 
-    monkeypatch.setattr(pf_power_variables, "acptmax", acc2252param.acptmax)
+    monkeypatch.setattr(costs.data.pf_power, "acptmax", acc2252param.acptmax)
 
     monkeypatch.setattr(costs.data.costs, "c22", acc2252param.c22)
 
diff --git a/tests/unit/models/test_costs_2015.py b/tests/unit/models/test_costs_2015.py
index e5dc1d2b4..f619c7ef4 100644
--- a/tests/unit/models/test_costs_2015.py
+++ b/tests/unit/models/test_costs_2015.py
@@ -6,7 +6,6 @@
 import pytest
 
 from process.data_structure import (
-    pf_power_variables,
     physics_variables,
     tfcoil_variables,
 )
@@ -15944,7 +15943,7 @@ def test_calc_remaining_subsystems(calcremainingsubsystemsparam, monkeypatch, co
     )
 
     monkeypatch.setattr(
-        pf_power_variables,
+        costs2015.data.pf_power,
         "ensxpfm",
         calcremainingsubsystemsparam.ensxpfm,
     )
diff --git a/tests/unit/models/test_power.py b/tests/unit/models/test_power.py
index 11e8c5b23..f2e9f140a 100644
--- a/tests/unit/models/test_power.py
+++ b/tests/unit/models/test_power.py
@@ -5,7 +5,6 @@
 
 from process.data_structure import (
     numerics,
-    pf_power_variables,
     physics_variables,
     tfcoil_variables,
 )
@@ -1761,29 +1760,29 @@ def test_pfpwr(pfpwrparam, monkeypatch, power):
 
     monkeypatch.setattr(power.data.heat_transport, "peakmva", pfpwrparam.peakmva)
 
-    monkeypatch.setattr(pf_power_variables, "pfckts", pfpwrparam.pfckts)
+    monkeypatch.setattr(power.data.pf_power, "pfckts", pfpwrparam.pfckts)
 
     monkeypatch.setattr(
-        pf_power_variables, "maxpoloidalpower", pfpwrparam.maxpoloidalpower
+        power.data.pf_power, "maxpoloidalpower", pfpwrparam.maxpoloidalpower
     )
 
     monkeypatch.setattr(
-        pf_power_variables, "peakpoloidalpower", pfpwrparam.peakpoloidalpower
+        power.data.pf_power, "peakpoloidalpower", pfpwrparam.peakpoloidalpower
     )
 
-    monkeypatch.setattr(pf_power_variables, "spfbusl", pfpwrparam.spfbusl)
+    monkeypatch.setattr(power.data.pf_power, "spfbusl", pfpwrparam.spfbusl)
 
-    monkeypatch.setattr(pf_power_variables, "poloidalpower", pfpwrparam.poloidalpower)
+    monkeypatch.setattr(power.data.pf_power, "poloidalpower", pfpwrparam.poloidalpower)
 
-    monkeypatch.setattr(pf_power_variables, "spsmva", pfpwrparam.spsmva)
+    monkeypatch.setattr(power.data.pf_power, "spsmva", pfpwrparam.spsmva)
 
-    monkeypatch.setattr(pf_power_variables, "vpfskv", pfpwrparam.vpfskv)
+    monkeypatch.setattr(power.data.pf_power, "vpfskv", pfpwrparam.vpfskv)
 
-    monkeypatch.setattr(pf_power_variables, "ensxpfm", pfpwrparam.ensxpfm)
+    monkeypatch.setattr(power.data.pf_power, "ensxpfm", pfpwrparam.ensxpfm)
 
-    monkeypatch.setattr(pf_power_variables, "acptmax", pfpwrparam.acptmax)
+    monkeypatch.setattr(power.data.pf_power, "acptmax", pfpwrparam.acptmax)
 
-    monkeypatch.setattr(pf_power_variables, "srcktpm", pfpwrparam.srcktpm)
+    monkeypatch.setattr(power.data.pf_power, "srcktpm", pfpwrparam.srcktpm)
 
     monkeypatch.setattr(
         power.data.pf_coil, "n_pf_coil_groups", pfpwrparam.n_pf_coil_groups
@@ -1871,27 +1870,27 @@ def test_pfpwr(pfpwrparam, monkeypatch, power):
         pfpwrparam.expected_peakmva
     )
 
-    assert pf_power_variables.pfckts == pytest.approx(pfpwrparam.expected_pfckts)
+    assert power.data.pf_power.pfckts == pytest.approx(pfpwrparam.expected_pfckts)
 
-    assert pf_power_variables.peakpoloidalpower == pytest.approx(
+    assert power.data.pf_power.peakpoloidalpower == pytest.approx(
         pfpwrparam.expected_peakpoloidalpower
     )
 
-    assert pf_power_variables.spfbusl == pytest.approx(pfpwrparam.expected_spfbusl)
+    assert power.data.pf_power.spfbusl == pytest.approx(pfpwrparam.expected_spfbusl)
 
-    assert pf_power_variables.poloidalpower == pytest.approx(
+    assert power.data.pf_power.poloidalpower == pytest.approx(
         pfpwrparam.expected_poloidalpower
     )
 
-    assert pf_power_variables.spsmva == pytest.approx(pfpwrparam.expected_spsmva)
+    assert power.data.pf_power.spsmva == pytest.approx(pfpwrparam.expected_spsmva)
 
-    assert pf_power_variables.vpfskv == pytest.approx(pfpwrparam.expected_vpfskv)
+    assert power.data.pf_power.vpfskv == pytest.approx(pfpwrparam.expected_vpfskv)
 
-    assert pf_power_variables.ensxpfm == pytest.approx(pfpwrparam.expected_ensxpfm)
+    assert power.data.pf_power.ensxpfm == pytest.approx(pfpwrparam.expected_ensxpfm)
 
-    assert pf_power_variables.acptmax == pytest.approx(pfpwrparam.expected_acptmax)
+    assert power.data.pf_power.acptmax == pytest.approx(pfpwrparam.expected_acptmax)
 
-    assert pf_power_variables.srcktpm == pytest.approx(pfpwrparam.expected_srcktpm)
+    assert power.data.pf_power.srcktpm == pytest.approx(pfpwrparam.expected_srcktpm)
 
 
 class AcpowParam(NamedTuple):
@@ -2059,12 +2058,12 @@ def test_acpow(acpowparam, monkeypatch, power):
     monkeypatch.setattr(power.data.heat_transport, "pacpmw", acpowparam.pacpmw)
 
     monkeypatch.setattr(
-        pf_power_variables,
+        power.data.pf_power,
         "i_pf_energy_storage_source",
         acpowparam.i_pf_energy_storage_source,
     )
 
-    monkeypatch.setattr(pf_power_variables, "srcktpm", acpowparam.srcktpm)
+    monkeypatch.setattr(power.data.pf_power, "srcktpm", acpowparam.srcktpm)
 
     power.acpow(output=False)
 
diff --git a/tests/unit/models/test_pulse.py b/tests/unit/models/test_pulse.py
index b5cae3512..b0f1c96bf 100644
--- a/tests/unit/models/test_pulse.py
+++ b/tests/unit/models/test_pulse.py
@@ -5,7 +5,6 @@
 
 from process.data_structure import (
     numerics,
-    pf_power_variables,
     physics_variables,
 )
 
@@ -1198,7 +1197,7 @@ def test_tohswg(tohswgparam, monkeypatch, pulse):
         tohswgparam.t_current_ramp_up_min,
     )
 
-    monkeypatch.setattr(pf_power_variables, "vpfskv", tohswgparam.vpfskv)
+    monkeypatch.setattr(pulse.data.pf_power, "vpfskv", tohswgparam.vpfskv)
 
     monkeypatch.setattr(
         pulse.data.pf_coil,