#51 first experiments

Author: Stefan Heid

experiments/issue51_new/stable_baselines.py

@@ -0,0 +1,103 @@
+from datetime import datetime
+from os import makedirs
+from typing import List
+
+import gym
+import numpy as np
+from stable_baselines3 import PPO
+from stable_baselines3.common.monitor import Monitor
+
+from openmodelica_microgrid_gym.env import PlotTmpl
+from openmodelica_microgrid_gym.net import Network
+from openmodelica_microgrid_gym.util import nested_map
+
+np.random.seed(0)
+
+timestamp = datetime.now().strftime(f'%Y.%b.%d %X ')
+makedirs(timestamp)
+
+# Simulation definitions
+net = Network.load('../../net/net_single-inv-curr.yaml')
+max_episode_steps = 300  # number of simulation steps per episode
+num_episodes = 1  # number of simulation episodes (i.e. SafeOpt iterations)
+iLimit = 30  # inverter current limit / A
+iNominal = 20  # nominal inverter current / A
+mu = 2  # factor for barrier function (see below)
+
+
+class Reward:
+    def __init__(self):
+        self._idx = None
+
+    def set_idx(self, obs):
+        if self._idx is None:
+            self._idx = nested_map(
+                lambda n: obs.index(n),
+                [[f'lc1.inductor{k}.i' for k in '123'], [f'inverter1.i_ref.{k}' for k in '012']])
+
+    def rew_fun(self, cols: List[str], data: np.ndarray) -> float:
+        """
+        Defines the reward function for the environment. Uses the observations and setpoints to evaluate the quality of the
+        used parameters.
+        Takes current measurement and setpoints so calculate the mean-root-error control error and uses a logarithmic
+        barrier function in case of violating the current limit. Barrier function is adjustable using parameter mu.
+
+        :param cols: list of variable names of the data
+        :param data: observation data from the environment (ControlVariables, e.g. currents and voltages)
+        :return: Error as negative reward
+        """
+        self.set_idx(cols)
+        idx = self._idx
+
+        Iabc_master = data[idx[0]]  # 3 phase currents at LC inductors
+        ISPabc_master = data[idx[1]]  # convert dq set-points into three-phase abc coordinates
+
+        # control error = mean-root-error (MRE) of reference minus measurement
+        # (due to normalization the control error is often around zero -> compared to MSE metric, the MRE provides
+        #  better, i.e. more significant,  gradients)
+        # plus barrier penalty for violating the current constraint
+        error = np.sum((np.abs((ISPabc_master - Iabc_master)) / iLimit) ** 0.5, axis=0) \
+            # + -np.sum(mu * np.log(1 - np.maximum(np.abs(Iabc_master) - iNominal, 0) / (iLimit - iNominal)), axis=0) \
+        # * max_episode_steps
+
+        return -np.clip(error.squeeze(), 0, 1e5)
+
+
+def xylables(fig):
+    ax = fig.gca()
+    ax.set_xlabel(r'$t\,/\,\mathrm{s}$')
+    ax.set_ylabel('$i_{\mathrm{abc}}\,/\,\mathrm{A}$')
+    ax.grid(which='both')
+    fig.savefig(f'{timestamp}/Inductor_currents.pdf')
+
+
+env = gym.make('openmodelica_microgrid_gym:ModelicaEnv_test-v1',
+               reward_fun=Reward().rew_fun,
+               viz_cols=[
+                   PlotTmpl([[f'lc.inductor{i}.i' for i in '123'], [f'inverter1.i_ref.{k}' for k in '012']],
+                            callback=xylables,
+                            color=[['b', 'r', 'g'], ['b', 'r', 'g']],
+                            style=[[None], ['--']]
+                            ),
+               ],
+               viz_mode='episode',
+               max_episode_steps=max_episode_steps,
+               net=net,
+               model_path='../../omg_grid/grid.network_singleInverter.fmu')
+
+with open(f'{timestamp}/env.txt', 'w') as f:
+    print(str(env), file=f)
+env = Monitor(env)
+
+model = PPO('MlpPolicy', env, verbose=1, tensorboard_log=f'{timestamp}/')
+model.learn(total_timesteps=1000000)
+model.save(f'{timestamp}/model')
+
+obs = env.reset()
+for _ in range(1000):
+    env.render()
+    action, _states = model.predict(obs, deterministic=True)
+    obs, reward, done, info = env.step(action)
+    if done:
+        break
+env.close()