IGBT leg

A block diagram and input parameters for IGBT leg are given in Table 1.

Table 1. An IGBT leg component in the Schematic Editor core library

component	component dialog window	component parameters
IGBT Leg		Control (Digital inputs, Internal modulator, Digital input per leg, Model) Digital input pins for: S1 (1..32(64)) S2(1..32(64)) gate_logic (active high, active low) Weight = 1

A schematic block diagram of the IGBT leg with corresponding IGBT arrangement and naming is given in Figure 1.

Selecting Digital inputs as the Control parameter enables assigning gate drive inputs to any of the digital input pins (from 1 to 32(64)). For example, if S1 is assigned to 1, the digital input pin 1 will be routed to theS1switch gate drive. In addition, the gate_logic parameter selects either active high(High-level input voltage VIH turns on the switch), or active low(Low-level input voltage VIL turns on the switch) gate drive logic, depending on the design of the external controller.

Selecting Internal modulator as the Control parameter, enables use of the internal PWM modulator for driving S_top and S_bot switches instead of digital input pins. In this configuration, two additional component inputs will be present. The En input is used to enable/disable the internal PWM modulator, while In is used as a reference signal input.

Selecting Digital input per leg as the Control parameter enables assigning the leg drive input to any of the digital input pins (from 1 to 32(64)). For example, if S_top is assigned to 1, the digital input pin 1 will be routed through the internal dead time module, to the S_top and S_bot switch gate drives.

Selecting Model as the Control parameter, enables setting of the IGBTs gate drive signals directly from the signal processing model. The input pin gates appears on the component. It is a 2-element vector input, where the first value (index 0) controls the S_top gate and the second value (index 1) controls the S_bot gate. When controlled from the model, logic is always active high.

DTV detection, when enabled DTV detection will be signaled during simulation runtime.

Timing

When Enable delays is enabled, turn on and turn off delay of the IGBTs will be included in the simulation. More information about this feature can be found on the dedicated section switching delay.

PESB Optimization

The PESB Optimization option is available in certain converter models. When PESB Optimization is enabled, all converter's short circuit state space modes will be merged and treated as the same state space mode. For example, if one converter leg within the three phase converter is short circuited and PESB Optimization is enabled, all of the legs within the three phase converter will also be short circuited. This simplification for short circuit modeling can save a significant amount of matrix memory.

Losses calculation

When the Losses calculation property is enabled, the component will calculate switching and conduction power losses for all switching elements (IGBTs and Diodes or MOSFETs). In the case of MOSFET switching elements, the Diode characteristic represents an internal MOSFET body diode. Switching power losses are calculated as a function of current, voltage, and temperature using 3D Look-up tables (LUTs). Also, 2D input for losses is supported. When a 2D losses table is inserted, it assumes only current and temperature dependance. From version 2020.3, conduction power losses can be defined as a function of current and temperature using Vt and Vd Look-up tables (the previous definition using Vce, Rce, Vd, and Rd properties are removed). These LUTs can be either 1D or 2D. If the LUT is a 1D table, the forward voltage drop depends only on current. If the LUT is a 2D table, the forward voltage drop dependence on the junction temperature is included.

In the MOSFET case under reverse current conduction, the current sharing calculation between the MOSFET channel and the internal body diode is performed. Import options and an explanation of how to correctly fill in all the necessary power loss parameters is described in the import power losses section.

Input/output power losses ports receive/generate vectors of four elements in the case of an IGBT switch type. The first element (index 0) is the upper IGBT, the second element (index 1) is the upper IGBT's diode. The last two elements are the bottom IGBT and its diode, respectively. In the case of a MOSFET switch type, power losses ports receive/generate vectors of 2 elements. The first element (index 0) is the upper MOSFET and the second element (index 1) is the bottom MOSFET.

• Switch type - property to select semiconductor type. Available options are IGBT and MOSFET.
• Current values - Switching elements current axis [A]
• Voltage values - Switching elements switching losses, voltage axis [V]
• Temp values - Switching elements temperature axis [°C]
• Forward voltage drop definition method - property to select how FVD will be defined. Available options are Voltage and Resistance and LUT - discontinued from the 2020.3 release
• Vce - IGBT collector emitter saturation voltage [V] - discontinued from the 2020.3 release
• Rce - IGBT on state slope resistance [Ohm] - discontinued from the 2020.3 release
• Vd - IGBT Diode voltage drop [V] - discontinued from the 2020.3 release
• Rd - IGBT Diode slope resistance [Ohm] - discontinued from the 2020.3 release
• Vt table - Switch forward voltage drop, f(I,T) [V]
• Vd table - Diode forward voltage drop, f(I,T) [V]
• Et on table - Switch switching ON losses, output energy, f(I, V, T) [J]
• Et off table - Switch switching OFF losses, output energy, f(I, V, T) [J]
• Ed off table - Diode switching OFF losses, output energy, f(I, V, T) [J]

Forward voltage drop

For IGBT switches, the input values for FVD are vectors of four elements. The first element (index 0) is the upper IGBT, the second element (index 1) is the upper IGBT's diode. The final two elements are the bottom IGBT and its diode, respectively. For MOSFET switches, the input/output ports are vectors of 2 elements. The first element (index 0) is the upper MOSFET and the second element (index 1) is the bottom MOSFET.

Temperatures calculation

Output Voltage Comparator

Output Voltage Comparator signal is available in the digital signal list of models that contain IGBT Leg components. One such signal is generated for each IGBT Leg used in the model, under the name "component_name_vout_cmp", where component_name is IGBT Leg component's name in the Schematic Editor.

Digital Alias

If a converter is controlled by digital inputs, an alias for every digital input used by the converter will be created. Digital input aliases will be available under the Digital inputs list alongside existing Digital input signals. The alias will be shown as Converter_name.Switch_name, where Converter_name is name of the converter component and Switch_name is name of the controllable switch in the converter.

Oversampling setting (Advanced tab)

With this property, you can select which GDS oversampling algorithm will be used in the component. There are two options: Global GDS oversampling and Switch-level GDS oversampling. More informations about these algorithms can be found in the dedicated documentation pages. Switch-level GDS oversampling is suitable for applications which use a high switching frequency and where more than one GDS transition can happen during one simulation step. Typical examples are Dual-Active-Bridge and Resonant converter applications.