制定约束时的 Pyomo 错误

Question

我正在尝试制定一个电池优化问题来优化电池充电/放电。 配方如下：

model = pyo.ConcreteModel()

#Set time period
model.timesteps = pyo.Set(initialize=pyo.RangeSet(len(pv)),ordered=True)

#Parameters
model.b_efficiency  = pyo.Param(initialize=etta)
model.b_cap = pyo.Param(initialize=battery_capacity)
model.b_min_soc = pyo.Param(initialize=battery_soc_min)
model.b_max_soc = pyo.Param(initialize=battery_soc_max)
model.b_charging_rate = pyo.Param(initialize=battery_charge_rate)

model.Ppv = pyo.Param(model.timesteps,initialize=dict(enumerate(pv,1)),within=pyo.Any)
model.Pdemand = pyo.Param(model.timesteps, initialize=dict(enumerate(demand,1)),within=pyo.Any)

#Variables
model.Pbat_ch = pyo.Var(model.timesteps, within = pyo.NonNegativeReals)
model.Pbat_dis = pyo.Var(model.timesteps, within = pyo.NonNegativeReals)
model.Ebat = pyo.Var(model.timesteps, within = pyo.NonNegativeReals)
model.Pgrid = pyo.Var(model.timesteps, within = pyo.NonNegativeReals)

# Define the constraints of the model

def BatEnergyBounds(model, t):
    return model.b_min_soc * model.b_cap <= model.Ebat[t] <= model.b_max_soc * model.b_cap

model.cons1 = pyo.Constraint(model.timesteps, rule = BatEnergyBounds)

def BatChargingBounds(model, t):
    return 0 <= model.Pbat_ch[t] <= model.b_charging_rate

model.cons2 = pyo.Constraint(model.timesteps, rule = BatChargingBounds)

def BatDischargingBounds(model, t):
    return 0 <= model.Pbat_dis[t] <= model.b_charging_rate

model.cons3 = pyo.Constraint(model.timesteps, rule = BatDischargingBounds)

def BatEnergyRule(model, t):
    if t == model.timesteps.first():
        return model.Ebat[t] == model.b_cap/2
    else:  
        return model.Ebat[t] == model.Ebat[t-1] + (model.b_efficiency * model.Pbat_ch[t] - model.Pbat_dis[t]/model.b_efficiency)

model.cons4 = pyo.Constraint(model.timesteps, rule = BatEnergyRule)

def PowerBalanceRule(model, t):
    return model.Pgrid[t] == model.Ppv[t] - model.Pdemand[t] + model.Pbat_dis[t] - model.Pbat_ch[t] 

model.cons5 = pyo.Constraint(model.timesteps, rule = PowerBalanceRule)

# Define the objective function
def ObjRule(model):
    return sum(model.Pgrid[t] for t in model.timesteps)

model.obj = pyo.Objective(rule = ObjRule, sense = pyo.minimize)

但是，我收到以下错误：

PyomoException: Cannot convert non-constant Pyomo expression (1.0  <=  Ebat[1]) to bool.
This error is usually caused by using a Var, unit, or mutable Param in a
Boolean context such as an "if" statement, or when checking container
membership or equality. For example,
    >>> m.x = Var()
    >>> if m.x >= 1:
    ...     pass
and
    >>> m.y = Var()
    >>> if m.y in [m.x, m.y]:
    ...     pass
would both cause this exception.

似乎该错误是由我在 cons4 中使用的 IF 语句引起的。 知道是什么导致了错误吗？

Answer 1

目前尚不清楚是什么导致了错误。 如果您正在寻求有关错误的帮助，最好提供一个示例，该示例通过确切的堆栈跟踪等自行产生错误。

您的“示例”代码会产生错误，因为您使用的条件if语句取决于变量的值，这是不允许的。 您在主程序中的代码没有这样做，所以看起来不错。

如果您遇到困难，请使用完全可重现的示例编辑您的帖子。