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Implement first-order filter

**Library:**Simscape / Electrical / Specialized Power Systems / Control / Filters

The First-Order Filter block implements one of the following transfer
functions based on the **Filter type** selected in the block parameters
window.

Low-pass filter:

$$H(s)=\frac{1}{1+Ts}$$

High-pass filter:

$$\begin{array}{c}H(s)=\frac{Ts}{1+Ts}\\ s=\text{Laplaceoperator}\\ T=\text{timeconstant}\end{array}$$

The key characteristics of the First-Order Filter block are:

The input accepts a vectorized input of N signals and implements N filters. This feature is particularly useful for designing controllers in three-phase systems (

*N*= 3).You can initialize filter states for specified DC and AC inputs.

The block enables you to compute and plot filter response.

Direct Feedthrough | Yes |

Sample Time | Specified in the Sample Time
parameterContinuous if Sample
Time = 0 |

Scalar Expansion | Yes, of the parameters |

States | One state per filter |

Dimensionalized | Yes |

The `power_FirstOrderFilter`

example shows various uses of
the First-Order Filter block using two **Filter type**
parameter settings (`Lowpass`

and
`Highpass`

).

The model sample time is parameterized with variable Ts (default value Ts =
`50e-6`

). To simulate continuous filters, specify Ts =
`0`

at the MATLAB^{®} command prompt before you start.