Battery Voltage Monitoring

Monitor for battery voltage

Since R2022b

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Libraries:
Simscape / Battery / BMS / Protection

Description

The Battery Voltage Monitoring block monitors the voltage of a battery. Voltage protection is necessary in electrical circuits. A battery that is exposed to extremely high or extremely low voltages can enter a dangerously unstable state.

You can switch between continuous and discrete implementations of the block by using the Sample time (-1 for inherited) parameter. To configure the block for continuous time, set the Sample time (-1 for inherited) parameter to 0. To configure the block for discrete time, set the Sample time (-1 for inherited) parameter to a positive, nonzero value, or to -1 to inherit the sample time from an upstream block.

This diagram shows the structure of the block:

Equations

This block computes the undervoltage symptom with this equation:

$$UndervoltageSymptom=min\left(CellVoltage\right)\le UndervoltageLimit$$

This block computes the overvoltage symptom with this equation:

$$OvervoltageSymptom=\max \left(CellVoltage\right)\ge OvervoltageLimit$$

This block computes the faulty sensor symptom with this equation:

$$FaultySensorSymptom=\left|PackVoltage-{\displaystyle \sum _{i-1}^{n}CellVoltag{e}^i}\right|\ge FaultySensorThreshold$$

The check on the sum of the cell voltages assumes that all the cells are in series.

The Battery Voltage Monitoring block then passes these symptoms to a Fault Qualification block, which qualifies the errors.

Examples

Battery Monitoring

Use battery management system blocks to monitor the current and temperature of a battery. A random current and temperature profile is applied to the battery which is then simulated for 6 hours.

• Open Model

Ports

Input

CellVoltage — Cell voltage, V

scalar | vector

Cell voltage, in volt, specified as a scalar for a single cell or a vector for multiple cells.

PackVoltage — Battery pack voltage, V

scalar

Battery pack voltage, in volt, specified as a scalar.

Output

UndervoltageError — Indication of undervoltage error

0 | 1

Indication of an undervoltage error. If this output is equal to 1, the battery is in an undervoltage state.

OvervoltageError — Indication of overvoltage error

0 | 1

Indication of an overvoltage error. If this output is equal to 1, the battery is in an overvoltage state.

SensoryFaultyError — Indication of sensor faulty error

0 | 1

Indication of a sensor faulty error. If this output is equal to 1, the sensor is faulty.

Parameters

Undervoltage limit (V) — Undervoltage limit

2.5 (default) | positive scalar

Voltage limit under which the battery is in an undervoltage state, in volt.

Overvoltage limit (V) — Overvoltage limit

4.5 (default) | positive scalar

Voltage limit over which the battery is in an overvoltage state, in volt. The value of this parameter must be greater than the value of the Undervoltage limit (V) parameter.

Voltage sensor fault threshold (V) — Threshold for voltage sensor fault

0.25 (default) | positive scalar

Voltage threshold over which the sensor is faulty, in volt.

Qualification time undervoltage (s) — Undervoltage qualification time

2 (default) | positive scalar

Time required to qualify the undervoltage error, in seconds.

Disqualification time undervoltage (s) — Undervoltage disqualification time

0 (default) | nonnegative scalar

Time required to disqualify the undervoltage error, in seconds. If you set this parameter to 0, the block does not disqualify the error.

Qualification time overvoltage (s) — Overvoltage qualification time

2 (default) | positive scalar

Time required to qualify the overvoltage error, in seconds.

Disqualification time overvoltage (s) — Overvoltage disqualification time

0 (default) | nonnegative scalar

Time required to disqualify the overvoltage error, in seconds. If you set this parameter to 0, the block does not disqualify the error.

Qualification time faulty sensor (s) — Faulty sensor qualification time

2 (default) | positive scalar

Time required to qualify the faulty sensor error, in seconds.

Disqualification time faulty sensor (s) — Faulty sensor disqualification time

0 (default) | nonnegative scalar

Time required to disqualify the faulty sensor error, in seconds. If you set this parameter to 0, the block does not disqualify the error.

Sample time (-1 for inherited) — Block sample time

-1 (default) | 0 | positive integer

Time between consecutive block executions. During execution, the block produces outputs and, if appropriate, updates its internal state. For more information, see What Is Sample Time? and Specify Sample Time.

For inherited discrete-time operation, specify this parameter as -1. For discrete-time operation, specify this parameter as a positive integer. For continuous-time operation, specify this parameter as 0.

If this block is in a masked subsystem or a variant subsystem that allows you to switch between continuous operation and discrete operation, promote the sample time parameter. Promoting the sample time parameter ensures correct switching between the continuous and discrete implementations of the block. For more information, see Promote Block Parameters on a Mask.

Algorithm data type — Option to choose data type for block algorithm

Inherit: auto (default) | double | single | <data type expression>

Since R2025a

Option to choose the data type for the block algorithm, specified as one of these values:

• Inherit: auto — You can simulate the block in both single and double precision. You must explicitly provide the inputs and parameters as either single or double.

• double — The block algorithm casts all inputs and parameters to double data type.

• single — The block algorithm casts all inputs and parameters to single data type.

• <data type expression> — The block algorithm casts all inputs and parameters to the data type object you specify.

Click the Show data type assistant button to display the Data Type Assistant, which helps you set the data type attributes. For more information, see Specify Data Types Using Data Type Assistant and Control Data Types of Signals.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2022b

R2025a: Switch between single-precision and double-precision floating-point simulation using Algorithm data type parameter

You can now easily switch between single-precision and double-precision floating-point simulation of the block algorithm by using the Algorithm data type parameter.