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Calculate efficiency as function of dissipated power losses

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

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

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

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

= elec_getEfficiency(`'loadIdentifier'`

,`node`

)

Before you call this function, you must have the simulation
log variable in your current workspace. Create the simulation log
variable by simulating the model with data logging turned on, or load
a previously saved variable from a file. If `node`

is
the name of the simulation log variable, then the table contains the
data for all semiconductor blocks in the model. If `node`

is
the name of a node in the simulation data tree, then the table contains
the data only for the blocks within that node.

Checking efficiency allows you to determine if circuit components
are operating within their requirements. All blocks in the Semiconductor
Devices library, as well as some other blocks, have an internal variable
called `power_dissipated`

, which represents the instantaneous
power dissipated by the block. This instantaneous dissipated power
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 `elec_getPowerLossTimeSeries`

function
also allows you to access this data.

The `elec_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

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

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, the N-Channel
MOSFET block has separate `power_dissipated`

logging
nodes for the MOSFET, the gate resistor, and for the source and drain
resistors if they have nonzero resistance values. The function sums
all these losses 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.

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

= elec_getEfficiency(`'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`

]
= elec_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.

`elec_getPowerLossSummary`

| `elec_getPowerLossTimeSeries`

- About Simulation Data Logging (Simscape)
- About the Simscape Results Explorer (Simscape)