Module: powerStorageBase

Executive Summary

The PowerStorageBase is a base class that is used generate a standard interface and list of features for modules that store electrical power. This class is used by other modules as a parent class and cannot be instantiated by itself. All Basilisk power storage modules based on this PowerStorageBase inherit the following common properties:

1. Writes out a PowerStorageStatusMsgPayload containing the current stored power (in Watt-Seconds or Joules), the current net power (in Watts), and the battery storage capacity (in Watt-Seconds or Joules).

2. Allows for multiple PowerNodeUsageMsgPayload corresponding to individual Module: powerNodeBase instances to be subscribed to using the addPowerNodeToModel method.

3. Iterates through attached PowerNodeUsageMsgPayload instances and computes the net power over all messages using sumAllInputs()

4. Computes the conversion between net power in and storage using the evaluateBatteryModel method, which must be overridden in child classes and is therefore module-specific.

Core functionality is wrapped in the evaluateBatteryModel protected virtual void method, which is assumed to compute power storage on a module specific mathematical model.

Protected methods prepended with custom are intended for module developers to override with additional, module-specific functionality.

For more information on how to set up and use classes derived from this module, see the simple power system example: scenarioPowerDemo

Module Assumptions and Limitations

The base class makes no specific energy storage device related assumptions.

Message Connection Descriptions

The following table lists all the module input and output messages. The module msg connection is set by the user from python. The msg type contains a link to the message structure definition, while the description provides information on what this message is used for.

Module I/O Messages

Msg Variable Name	Msg Type	Description
batPowerOutMsg	PowerStorageStatusMsgPayload	power storage status output message
nodePowerUseInMsgs	PowerNodeUsageMsgPayload	vector of power node input messages (these are linked through the addPowerNodeToModel(msg) method

User Guide

• The base class behavior requires the initial energy storage to be specified through storedCharge_Init.

• The integration time step is evaluated as the time between module calls.

• The user must set the output message name variable batPowerOutMsg

• The input message names are provided by calling the method addPowerNodeToModel(msg)

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class PowerStorageBase : public SysModel

#include <powerStorageBase.h>

power storage base class

Public Functions

PowerStorageBase()

This method initializes some basic parameters for the module.

Returns

void

~PowerStorageBase()

Destructor.

Returns

void

void Reset(uint64_t CurrentSimNanos)

This method is used to reset the module.

Returns

void

void addPowerNodeToModel(Message<PowerNodeUsageMsgPayload> *tmpNodeMsg)

Adds a PowerNodeUsageMsgPayload input message to iterate over

Parameters

tmpNodeMsg – Message name corresponding to a PowerNodeUsageMsgPayload.

Returns

void

void UpdateState(uint64_t CurrentSimNanos)

Implements readMessages, integratePowerStatus, and writeMessages for the rest of the sim.

Parameters

currentSimNanos – The current simulation time in nanoseconds

Returns

void

Public Members

std::vector<ReadFunctor<PowerNodeUsageMsgPayload>> nodePowerUseInMsgs

Vector of power node input message names.

Message<PowerStorageStatusMsgPayload> batPowerOutMsg

power storage status output message

double storedCharge_Init

[W-s] Initial stored charge set by the user. Defaults to 0.

BSKLogger bskLogger

&#8212; BSK Logging

Protected Functions

void writeMessages(uint64_t CurrentClock)

Writes out one PowerStorageStatusMsgPayload

Parameters

CurrentClock – The current time used for time-stamping the message

Returns

void

bool readMessages()

This method is used to read the incoming power supply/usage messages and store them for future use.

Returns

void

void integratePowerStatus(double currentTime)

Integrates the net power given the current time using a simple Euler method.

This method integrates the power use provided by the attached modules.

Returns

void

double sumAllInputs()

Sums over the input power consumption messages.

This method sums over the power used/generated by the attached simPowerNodes.

Returns

double currentSum: current net power in Watts

virtual void evaluateBatteryModel(PowerStorageStatusMsgPayload *msg) = 0

Virtual function to represent power storage computation or losses.

virtual void customReset(uint64_t CurrentClock)

Custom Reset() method, similar to customSelfInit.

Custom Reset() method. This allows a child class to add additional functionality to the Reset() method

Returns

void

virtual void customWriteMessages(uint64_t currentSimNanos)

Custom Write() method, similar to customSelfInit.

custom Write method, similar to customSelfInit.

Returns

void

virtual bool customReadMessages()

Custom Read() method, similar to customSelfInit.

Custom read method, similar to customSelfInit; returns true by default.

Returns

void

Protected Attributes

PowerStorageStatusMsgPayload storageStatusMsg

class variable

std::vector<PowerNodeUsageMsgPayload> nodeWattMsgs

class variable

double previousTime

Previous time used for integration.

double currentTimestep

[s] Timestep duration in seconds.

double storedCharge

[W-s] Stored charge in Watt-hours.

double currentPowerSum

[W] Current net power.