Calculate efficiency as a function of dissipated power losses

`efficiency = pe_getEfficiency('loadIdentifier',node)`

`efficiency = pe_getEfficiency('loadIdentifier',node,startTime,endTime)`

```
[efficiency,lossesTable]
= pe_getEfficiency('loadIdentifier',node)
```

returns the efficiency of a circuit based on the data extracted from a Simscape™ logging node.`efficiency`

= pe_getEfficiency(`'loadIdentifier'`

,`node`

)

Before you call this function, generate or load the simulation log variable to your
workspace. To generate the variable, simulate the model with simulation data logging
enabled. For more information, see About Simulation Data Logging (Simscape). To load a
previously saved variable from a file, right-click on the file and select
**Load**.

Checking efficiency allows you to determine if circuit components are operating within
their requirements. Blocks in the Semiconductor > Fundamental Components library and the
Delta-Connected Load, Wye-Connected Load, and
RLC (Three-Phase) blocks have an internal block variable
called *power_dissipated*. This variable represents the instantaneous
dissipated power, which includes only the real power (not the reactive or apparent power)
that the block dissipates. When you log simulation data, the time-value series for this
variable represents the power dissipated by the block over time. You can view and plot this
data using the Simscape Results Explorer. The `ee_getPowerLossTimeSeries`

function also allows you to access this data.

The `pe_getEfficiency`

function calculates the efficiency of the
circuit based on the losses for blocks that have a *power_dissipated*
variable and that you identify as a load block. The equation for efficiency is

$$Eff=100*\frac{{P}_{load}}{{P}_{loss}+{P}_{load}},$$

where:

*Eff*is the efficiency of the circuit.*P*is the output power, that is, the power dissipated by load blocks._{load}*P*is the power dissipated by nonload blocks._{loss}

This equation assumes that all loss mechanisms are captured by blocks containing at
least one *power_dissipated* variable. If the model contains any lossy
blocks that do not have this variable, the efficiency calculation gives incorrect
results.

Some blocks have more than one *power_dissipated* variable, depending
on their configuration. For example, for the MOSFET (Ideal, Switching) block,
both the `diode`

node and the `ideal_switch`

node have a
`power_dissipated`

logging node. The function sums the power losses for
both nodes to provide the total power loss for the block, averaged over simulation time. The
function uses the loss data to calculate the efficiency of the circuit.

The nonideal semiconductor blocks also have thermal variants. Thermal variants have thermal ports that allow you to model the heat that is generated due to switching events and conduction losses. If you use a thermal variant, the function calculates power losses and efficiencies based on the thermal parameters that you specify. Essentially, the power dissipated is equal to the heat generated.

If you use a variant without a thermal port, the function calculates power losses and efficiencies based on the electrical parameters that you specify, such as on-state resistance and off-state conductance.

`efficiency = pe_getEfficiency(`

returns the efficiency of a circuit based on the `'loadIdentifier'`

,`node`

,`startTime`

,`endTime`

)*power_dissipated* data
extracted from a Simscape logging node within a time interval. `startTime`

and
`endTime`

represent the start and end of the time interval for
calculating the efficiency. If you omit these two input arguments, the function calculates
the efficiency over the whole simulation time.

`[`

returns the efficiency of a circuit and the power loss contributions of the nonload blocks
in a circuit based on the data extracted from a Simscape logging node.`efficiency`

,`lossesTable`

]
= pe_getEfficiency(`'loadIdentifier'`

,`node`

)

The output power equals the total power dissipated by blocks that you identify as load blocks.

The input power equals the output power plus the total power dissipated by blocks that you do not identify as load blocks.

The

*power_dissipated*variables capture all loss contributions.

`ee_getEfficiency`

| `ee_getPowerLossSummary`

| `ee_getPowerLossTimeSeries`

| `sscexplore`

- Perform a Power-Loss Analysis
- Data Logging (Simscape)
- About the Simscape Results Explorer (Simscape)