Floating Neutral (Three-Phase)

Internal floating neutral point for wye-connected network

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Libraries:
Simscape / Electrical / Connectors & References

Description

The Floating Neutral (Three-Phase) block connects the individual phases of a three-phase system to form a floating neutral point.

Note

To create a neutral point that you can connect to blocks with single-phase ports, use the Neutral Port (Three-Phase) block. To create a neutral point that is connected to ground, use the Grounded Neutral (Three-Phase) block.

Examples

Earthing Effects with Unbalanced Load

The effects of three different types of earthing connections on network voltages and currents.

• Open Model

Control Speed of Induction Machine with Direct Torque Control Method

Control an asynchronous machine (ASM) using the direct-torque control method. A PI-based speed controller supplies the torque reference. The direct-torque controller generates the inverter pulses.

• Open Model

Asynchronous Machine Scalar Control

Control the rotor speed in an asynchronous machine (ASM) drive using the scalar V/f control method. The converter transforms a reference speed to a reference electrical frequency. The controller generates reference voltages from the reference frequency by maintaining a constant voltage-to-frequency ratio through scalar V/f control.

• Open Model

Electric Engine Dyno

Model an electric vehicle dynamometer test. The test environment contains an asynchronous machine (ASM) and an interior permanent magnet synchronous machine (IPMSM) connected back-to-back through a mechanical shaft. Both machines are fed by high-voltage batteries through controlled three-phase converters. The 164 kW ASM produces the load torque. The 35 kW IPMSM is the electric machine under test. The Control Machine Under Test (IPMSM) subsystem controls the torque of the IPMSM. The controller includes a multi-rate PI-based control structure. The rate of the open-loop torque control is slower than the rate of the closed-loop current control. The task scheduling for the controller is implemented as a Stateflow® state machine. The Control Load Machine (ASM) subsystem uses a single rate to control the speed of the ASM. The Visualization subsystem contains scopes that allow you to see the simulation results.

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Ports

Conserving

~ — Composite three-phase port

electrical

Electrical conserving port representing the three phases of the three-phase block. For more information, see Three-Phase Ports.

Dependencies

To enable this port, set the Electrical connection parameter to Composite three-phase ports.

a — Phase a of three-phase system

electrical

Electrical conserving port associated with the phase a of the three-phase block.

Dependencies

To enable this port, set the Electrical connection parameter to Expanded three-phase ports.

b — Phase b of three-phase system

electrical

Electrical conserving port associated with the phase b of the three-phase block.

Dependencies

To enable this port, set the Electrical connection parameter to Expanded three-phase ports.

c — Phase c of three-phase system

electrical

Electrical conserving port associated with the phase c of the three-phase block.

Dependencies

To enable this port, set the Electrical connection parameter to Expanded three-phase ports.

Parameters

Electrical connection — Whether to model composite or expanded three-phase ports

Composite three-phase ports (default) | Expanded three-phase ports

Since R2026a

Whether to model composite or expanded three-phase ports.

Composite three-phase ports represent three individual electrical conserving ports with a single block port. You can use composite three-phase ports to build models that correspond to single-line diagrams of three-phase electrical systems.

Expanded three-phase ports represent the individual phases of a three-phase system using three separate electrical conserving ports.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

Parameter:	port_option
Values:	"ee.enum.threePhasePort.composite" (default) | "ee.enum.threePhasePort.expanded"

Parasitic ground conductance — Parasitic ground conductance

1e-12 1/Ohm (default)

Parasitic conductance to ground. A nonzero value is required for the simulation of some circuit topologies.

Extended Capabilities

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

Version History

Introduced in R2013b

R2026a: The Modeling option parameter has changed

The Modeling option parameter has been replaced with the Electrical connection parameter. You can now also set this parameter value programmatically by using the set_param function.

If you created a model containing this block in an earlier release, the software now automatically sets the value of the Electrical connection parameter to the previous value of the Modeling option parameter.