Battery Energy storage

GridLAB-D™ contains both a generic energy storage object as well as a battery energy storage object. Both are described here.

Synopsis

battery

A battery energy storage device is defined using the battery object.

    module generators;
class battery {
    enumeration {UNKNOWN, CONSTANT_V, CONSTANT_PQ, CONSTANT_PF, SUPPLY_DRIVEN, POWER_DRIVEN, VOLTAGE_CONTROLLED, POWER_VOLTAGE_HYBRID} generator_mode ;
    enumeration {NONE=0, LINEAR_TEMPERATURE=1} additional_controls;
    enumeration {OFFLINE=1, ONLINE=2} generator_status;
    enumeration {HOUSEHOLD, SMALL=1, MED_COMMERCIAL, MED_HIGH_ENERGY, LARGE} rfb_size;
    enumeration {AC=2, DC=1} power_type;
    enumeration {CHARGING=1, DISCHARGING=2, WAITING=0, FULL=3, EMPTY=4, CONFLICTED=5} battery_state;
    double number_battery_state_changes;
    double monitored_power[W];
    double power_set_high[W];
    double power_set_low[W];
    double power_set_high_highT[W];
    double power_set_low_highT[W];
    double check_power_low[W];
    double check_power_high[W];
    double voltage_set_high[V];
    double voltage_set_low[V];
    double deadband[V];
    double sensitivity;
    double high_temperature;
    double midpoint_temperature;
    double low_temperature;
    double scheduled_power[W];
    double Rinternal[Ohm];
    double V_Max[V];
    double I_Max[A];
    double E_Max[Wh];
    double P_Max[W];
    double power_factor;
    double Energy[Wh];
    double efficiency[unit];
    double base_efficiency[unit];
    double parasitic_power_draw[W];
    double Rated_kVA[kVA];
    complex V_Out[V];
    complex I_Out[A];
    complex VA_Out[VA];
    complex V_In[V];
    complex I_In[I];
    complex V_Internal[V];
    complex I_Internal[A];
    complex I_Prev[A];
    double power_transfered;
    set {A,B,C,N,S} phases;
    bool use_internal_battery_model; 
    enumeration {UNKNOWN, LI_ION, LEAD_ACID} battery_type; 
    double nominal_voltage[V];
    double rated_power[W];
    double battery_capacity[Wh];
    double round_trip_efficiency[pu];
    double state_of_charge[pu];
    double battery_load[W];
    double reserve_state_of_charge[pu];
}

energy_storage

A generic, technology agnostic energy storage device is defined with the energy_storage object.

module generators;
class energy_storage {
    enumeration {SUPPLY_DRIVEN=4, CONSTANT_PF=3, CONSTANT_PQ=2, CONSTANT_V=1, UNKNOWN=0} generator_mode;
    enumeration {ONLINE=2, OFFLINE=1} generator_status;
    enumeration {DC=0, AC=1} power_type;
    double Rinternal;
    double V_Max[V];
    complex I_Max[A];
    double E_Max;
    double Energy;
    double efficiency;
    double Rated_kVA[kVA];
    complex V_Out[V];
    complex I_Out[A];
    complex VA_Out[VA];
    complex V_In[V];
    complex I_In[A];
    complex V_Internal[V];
    complex I_Internal[A];
    complex I_Prev[A];
    set {S=112, N=8, C=4, B=2, A=1} phases;
}

Properties

Property Table

Property name	Type	Unit	Description
generator_mode	enumeration	none	(UNKNOWN, CONSTANT_V, CONSTANT_PQ, CONSTANT_PF, SUPPLY_DRIVEN, POWER_DRIVEN, VOLTAGE_CONTROLLED, POWER_VOLTAGE_HYBRID) All modes are implemented except for VOLTAGE_CONTROLLED.
generator_status	enumeration	none	(ONLINE, OFFLINE)
additional_controls	enumeration	none	(NONE, LINEAR_TEMPERATURE) Allows for additional controls to account for the climate region battery is in.
rfb_size	enumeration	none	(HOUSEHOLD, SMALL,MED_COMMERCIAL, MED_HIGH_ENERGY, LARGE) Selection sets different defaults for maximum voltage, power, energy capacity, current, and the battery efficiency.
power_type	enumeration	none	(AC, DC) Not currently used
battery_state	enumeration	none	(CHARGING, DISCHARGING, WAITING, FULL, EMPTY, CONFLICTED)
number_battery_state_changes	double
monitored_power	double	W
power_set_high	double	W
power_set_low	double	W
power_set_high_highT	double	W
power_set_low_highT	double	W
check_power_low	double	W
check_power_high	double	W
voltage_set_high	double	V
voltage_set_low	double	V
deadband	double	V
sensitivity	double
high_temperature	double	degF
midpoint_temperature	double	degF
low_temperature	double	degF
scheduled_power	double	W
Rinternal	double	Ohm
V_Max	double	V
I_Max	complex	A
E_Max	double	Wh
P_Max	double	W
power_factor	double	pu
Energy	double	Wh
efficiency	double	unit
base_efficency	double	unit
parasitic_power_draw	double	W
rated_kVA	double kVA
V_Out	complex	V
I_Out	complex	A
VA_Out	complex	VA
V_In	complex	V
V_Internal	complex	V
I_Internal	complex	A
I_Prev	complex	A
power_transfered	double
phases	set	none	(A, B, C, N, S)

Table 1: Properties only used for internal battery module
Property Name	Type	Unit	Description
use_internal_battery_model	bool	none	Boolean flag to use internal battery model. Default is FALSE.
nominal_voltage	double	V	Battery's nominal voltage
rated_power	double	W	Maximum rated power of battery. Can be set in inverter in rated_battery_power.
battery_capacity	double	Wh	Maximum energy capacity of battery
round_trip_efficiency	double	pu	Round-trip efficiency of battery
state_of_charge	double	pu	Battery's current state of charge (SOC)
battery_load	double	W	Battery's current load. This is the value of power_in from the parent inverter.
reserve_state_of_charge	double	pu	The state of charge which the battery may not go below

Status

TODO - Status - update with energy storage models status

Example

TODO - Example - add example demonstrating energy storage model use case

Modules
- Generators
  - inverter
  - Centralized DG Controller