I am trying to apply q-learning to my custom reinforcement learning environment that is representing energy storage arbitrage (electricity trading with a battery,charge when prices are low and discharge when prices increase). The environment works but I am not able to apply q-learning to it. Below the environment is a script that is able to run the environment but I am unsure what I should make the state variable. Any ideas on how to apply q-learning to optimize the charge/discharge cycles? the reset function starts the next day from a dataset with hourly prices for electricity. picture of the dataframe is below.
class BatteryEnv(gym.Env):
def __init__(self, df):
self.dict_actions = {0:'discharge',1:'charge',2:'wait'}
self.df = df
self.action_space = spaces.Discrete(3)
self.observation_space = spaces.Box(low=0, high=100, shape=(1,1))
self.reward_list = []
self.actual_load_list = []#observations
self.SOE_list=[] #State of energy
self.state_idx = 0 #iteration (hour of the day)
self.SOE = 0 #SOE
self.MAX_charge = 20 #C-rate kinda
self.Capacity =100
def step(self, action):
#mapping integer to action for actual load calculation
str_action = self.dict_actions[action]
#increase state idx within episode (1= 1 hour)
self.state_idx+=1
#calculating our actual load
if str_action == 'charge' and self.SOE < self.Capacity:
SOE_charge = np.clip(self.Capacity - self.SOE, 0, self.MAX_charge)
self.SOE += SOE_charge
obs = SOE_charge * self.df['prices'][self.state_idx]
elif str_action == 'discharge' and self.SOE > 0:
SOE_discharge = np.clip(self.SOE, 0, self.MAX_charge)
self.SOE -= SOE_discharge
obs = -SOE_discharge * self.df['prices'][self.state_idx]
else:
self.SOE += 0
obs = 0 * self.df['prices'][self.state_idx]
# appending actual load to list for monitoring and comparison purposes
self.actual_load_list.append(obs)
self.SOE_list.append(self.SOE)
#reward system
if obs<0: #if observation is positive we spending money. if negative we earning
reward =1
else:
reward =-1
# appending curr reward to list for monitoring and comparison purposes
self.reward_list.append(reward)
#checking whether our episode (day interval) ends
if self.df.iloc[self.state_idx,:].Daynum != self.df.iloc[self.state_idx-1].Daynum:
done = True
else:
done = False
return obs, reward, done
def reset(self):
return df.iloc[self.state_idx,:]
def render():
pass
The below codes are able to to show that the environment is working.
for episode in range(7):
observation = env.reset()
for t in range(24): #can't be smaller than 24 as 24 time points equal to 1 episode (1 day)
#print(observation)
action = env.action_space.sample() #random actions
observation, reward, done = env.step(action)
if done:
print("Episode finished after {} timesteps".format(t+1)), print (observation), print(reward)
break
I think I was able to make the code sort of work with Q-learning. However, the reward and reset function needs some work to perform better.
class BatteryEnv(gym.Env):
def __init__(self, prices = np.array(df.prices), daynum = np.array(df.Daynum)):
#self.df = df
self.prices = prices
self.daynum = daynum
self.dict_actions = {0:'discharge',1:'charge',2:'wait'}
self.action_space = spaces.Discrete(3)
# our observation space is just one float value - our load
self.observation_space = spaces.Box(low=0, high=100, shape=(1,1))
# reward list for monitoring
self.reward_list = []
# lists 4 monitoring
self.actual_load_list = []
self.SOE_list=[] #State of energy
self.chargio = [] #charge & discharge
self.SOEe=[] #State of energy
# index of current state within current episode
self.state_idx = 0 #iteration
self.SOE = 0 #SOE
self.MAX_charge = 20 #C-rate kinda
self.Capacity =100
self.state = 0
def step(self, action):
#mapping integer to action for actual load calculation
str_action = self.dict_actions[action]
#increase state idx within episode (day)
self.state_idx+=1
#calculating our actual load
if str_action == 'charge' and self.SOE < self.Capacity:
SOE_charge = np.clip(self.Capacity - self.SOE, 0, self.MAX_charge)
self.state += SOE_charge
self.SOEe.append(self.SOE)
self.chargio.append(SOE_charge)
obs = SOE_charge * self.prices[self.state_idx]
elif str_action == 'discharge' and self.SOE > 0:
SOE_discharge = np.clip(self.SOE, 0, self.MAX_charge)
self.state -= SOE_discharge
self.SOEe.append(self.SOE)
self.chargio.append(-SOE_discharge)
obs = -SOE_discharge * self.prices[self.state_idx]
else:
self.state += 0
self.chargio.append(0)
self.SOEe.append(self.SOE)
obs = 0
# appending actual load to list for monitoring and comparison purposes
self.actual_load_list.append(obs)
self.SOE_list.append(self.SOE)
#reward system
if obs<0: #if observation is positive we spending money. if negative we earning
reward =1
else:
reward =-1
# appending curr reward to list for monitoring and comparison purposes
self.reward_list.append(reward)
#checking whether our episode (day interval) ends
if self.daynum[self.state_idx] != self.daynum[self.state_idx-1]:
done = True
else:
done = False
info = {
#'step': self.state_idx,
'SOE': self.SOE,
#'reward': reward,
'chargio': self.chargio
}
return obs, reward, done, info
def reset(self):
self.state = 0
return self.state
def render():
pass
applying q-learning:
env.reset()
env = BatteryEnv()
discrete_os_size = [20] * len(env.observation_space.high)
discrete_os_win_size = (env.observation_space.high -
env.observation_space.low)/discrete_os_size
discrete_os_win_size #buckets of 10
learning_rate = 0.1
discount =0.95 #measure of how important future actions are
episodes =25000
q_table = np.random.uniform(low=-2, high=2, size=(discrete_os_size + [env.action_space.n]))
def get_discrete_state(state): #change SOE for other states
discrete_state = (state - env.observation_space.low)/discrete_os_win_size
return tuple(discrete_state.astype(np.int))
discrete_state =get_discrete_state(env.reset())
SOE=[]
for episode in range (episodes):
if episode % 5000 ==0:
print(episode)
discrete_state =get_discrete_state(env.reset())
done = False
while not done:
action = np.argmax(q_table[discrete_state])
new_state, reward, done, _ =env.step(action)
new_discrete_state = get_discrete_state(new_state)
if not done:
max_future_q = np.max(q_table[new_discrete_state])
current_q = q_table[discrete_state + (action,)]
new_q = (1-learning_rate) * current_q + learning_rate *(reward + discount * max_future_q)
q_table[discrete_state +(action,)] = new_q
#elif new_state[0] >= env.go:
discrete_state = new_discrete_state
SOE.append(new_state)
print(reward, new_state)