Implement three-phase circuit breaker opening at current zero crossing
The Three-Phase Breaker block implements a three-phase circuit breaker where the opening and closing times can be controlled either from an external Simulink® signal (external control mode), or from an internal control timer (internal control mode).
The Three-Phase Breaker block uses three Breaker blocks connected between the inputs and the outputs of the block. You can use this block in series with the three-phase element you want to switch. See the Breaker block reference pages for details on the modeling of the single-phase breakers.
If the Three-Phase Breaker block is set in external control mode, a control input appears in the block icon. The control signal connected to this input must be either 0 or 1, 0 to open the breakers, 1 to close them. If the Three-Phase Breaker block is set in internal control mode, the switching times are specified in the dialog box of the block. The three individual breakers are controlled with the same signal.
Series Rs-Cs snubber circuit are included in the model. They can be optionally connected to the three individual breakers. If the Three-Phase Breaker block happens to be in series with an inductive circuit, an open circuit or a current source, you must use the snubbers.
The initial status of the breakers. The initial status is the same for the three breakers. Depending on the initial status, the icon shows a closed contact or an open contact.
If selected, the switching of phase A is activated. If not selected, the breaker of phase A stays in its initial status specified in the Initial status of breakers parameter.
If selected, the switching of phase B is activated. If not selected, the breaker of phase B stays in its initial status specified in the Initial status of breakers parameter.
If selected, the switching of phase C is activated. If not selected, the breaker of phase C stays in its initial status specified in the Initial status of breakers parameter.
The Transition times(s) parameter is not visible in the dialog box if the External control of switching times parameter is selected.
Specify the vector of switching times when using the Three-Phase Breaker block in internal control mode. At each transition time the selected breakers opens or closes depending to their initial state.
If selected, adds a fourth input port to the Three-Phase Breaker block for an external control of the switching times of the breakers. The switching times are defined by a Simulink signal (0-1 sequence).
The internal breaker resistances, in ohms (Ω). The Breaker resistance Ron parameter cannot be set to 0.
The snubber resistances, in ohms (Ω). Set the Snubber resistance Rp parameter to inf to eliminate the snubbers from the model.
The snubber capacitances, in farads (F). Set the Snubber capacitance Cp parameter to 0 to eliminate the snubbers, or to inf to get resistive snubbers.
Select Breaker voltages to measure the voltage across the three internal breaker terminals.
Select Breaker currents to measure the current flowing through the three internal breakers. If the snubber devices are connected, the measured currents are the ones flowing through the breakers contacts only.
Select Breaker voltages and currents to measure the breaker voltages and the breaker currents.
Place a Multimeter block in your model to display the selected measurements during the simulation. In the Available Measurements list box of the Multimeter block, the measurements is identified by a label followed by the block name and the phase:
Ub <block name> /Breaker A: Ub <block name> /Breaker B:
Ub <block name> /Breaker C.
Ib <block name> /Breaker A: Ib <block name> /Breaker B:
Ib <block name> Breaker C.
If the Three-Phase Breaker block is set in external control mode, a Simulink input is added to the block to control the opening and closing of the three internal breakers.