Three Phase T Type Inverter

Schematic Block Diagram

A schematic block diagram of the inverter switching block with corresponding switch arrangement and naming, is given in Figure 2.

Weight of a Three phase T-type inverter component for real-time/VHIL simulation is 3.

Control

Selecting Digital input per switch as the Control parameter enables assigning gate drive inputs to any of the digital input pins (from 1 to 32(64)). For example, if Phase A S1 is assigned to 1, the digital input pin 1 will be routed to the Phase A S1 switch gate drive. In addition, the gate_logic parameter is set to 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 external controller design. In TyphoonSim, digital signals are read from the internal virtual IO bus. Hence, if some signal is sent to digital ouput 1, it will appear on digital input 1.

Selecting Internal modulator as the Control parameter, enables use of the internal PWM modulator for driving the switches instead of the digital input pins. In this configuration, four additional component inputs will be present. The En input is used to enable/disable the internal PWM modulator, while InA, InB, and InC are used as reference signal inputs. Overall, 6 PWM channels are used to drive the three level three phase NPC T type converter, 2 per phase. Reference signals for the 2 modulators that control the switches of a single phase leg are created from a single reference input. The block diagram of a one phase leg controlled by PWM modulators is shown in Figure 3. The input reference signal for one modulator has a value range between -1.0 and 1.0. This signal is split into two reference signals for two modulators, and set in a range from 0.0 to 1.0.

Internal modulator separated, when selected as the Control parameter, enables you to use the internal PWM modulator for driving the converter's switches instead of digital input pins. The additional component inputs and the number of created internal PWM modulators is the same as described above for the Internal modulator. Reference signals for 2 modulators, that are controlling the switches of a single phase leg, are provided to the component through a vectorized input (the value on index 0 controls the PWM_A_Ch1 modulator, while the value on index 1 controls the PWM_A_Ch2 modulator). The block diagram of a one phase leg separately controlled by PWM modulators is shown in Figure 4. The permissible range for the input reference signals is adjustable from the component mask.

Model, when selected as the Control parameter, enables you to set the IGBTs' gate drive signals directly from the signal processing model. The input pin 'gates' appears on the component and requires a vector input of twelve gate drive signals in the following order: [Phase A S1, Phase A S2,…, Phase B S1, Phase B S2,…, Phase C S1, Phase C S1,...]. When controlled from the model, logic is always active high.

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 switching delay section.

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 tables for losses is supported. When a 2D losses table is inserted, it assumes only current and temperature dependance. Conduction power losses can be defined as a function of current and temperature using Vt and Vd Look-up tables. 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, a current sharing calculation between the MOSFET channel and the internal body diode is performed. Import options and an explanation how to correctly fill all necessary power losses parameters is described in the import power losses section.

In the case of IGBT switch type for both Losses groups, input/output terminals for power losses power losses receive/generate vectors of 24 elements (every index in the vector represent one switching element). The first 8 elements (indexes 0-7) are related to the switching elements in phase A, the second 8 elements (indexes 8-15) are related to the switching elements in phase B and the last 8 elements (indexes 16-23) are related to the switching elements in phase C. In the case of MOSFET switch type for both Losses groups, input/output terminals for power losses receive/generate vectors of 12 elements (every index in the vector represent one switching element). The first 4 elements (indexes 0-3) are related to the switching elements in phase A, the second 4 elements (indexes 4-7) are related to the switching elements in phase B, and the last 4 elements (indexes 8-11) are related to the switching elements in phase C. If different switch types are used for Losses groups, input/output terminals for power losses receive/generate vectors of 18 elements, with the same ordering logic as previously described. Switching element ordering and group definition for each phase are described in the Losses calculation section. All switches are distributed in two groups, and for each group, different power loss parameters can be specified (Phase A S1, Phase A S4, Phase B S1, Phase B S4, Phase C S1, and Phase C S4 are in group 1, Phase A S2, Phase A S3, Phase B S2, Phase B S3, Phase C S2, and Phase C S3 are in group 2). Available Mask properties are:

• Losses groups - Switching elements group
• Current values - Switching elements current axis [A]
• Voltage values - Switching elements voltage axis [V]
• Temp values - Switching elements temperature axis [°C]
• Vt table - Switch forward voltage drop, f(I,T) [V]
• Vd table - Diode forward voltage drop, f(I,T) [V]
• Et on table out - Switch switching ON losses, output energy, f(I, V, T) [J]
• Et off table out - Switch switching OFF losses, output energy, f(I, V, T) [J]
• Ed off table out- Diode switching OFF losses, output energy, f(I, V, T) [J]

Temperatures calculation

When the Temperatures calculation property is enabled, the component will calculate the combined power losses (P_loss) and junction temperatures (T_junctions) for all switching elements (IGBTs and diodes). Combined power losses represent the sum of the calculated switching and conduction losses transferred through an internally generated Thermal network component. The internally generated Thermal network component also calculates junction temperatures from power losses, input case temperatures, and the provided thermal model parameters. Input/output ports for temperatures calculation are vectors of up to 24 elements and they are indexed in the same way as explained in the Losses calculation section.

Additional temperatures calculation mask properties include:

• Thermal networks type - Defines the type of internal thermal network
• Rth switch - List of thermal resistances for the IGBT switch
• Tth switch / Cth switch - List of thermal time constants or thermal capacitances for the IGBT switch
• Rth diode - List of thermal resistance for the diode
• Tth diode / Cth diode - List of thermal time constants or thermal capacitances for the diode
• Calculation execution rate - Execution rate in [s] for the losses and temperatures calculation logic

Vienna rectifier optimization

Vienna rectifier optimization is activated through the corresponding checkbox in the Advanced tab. Sx_1 and Sx_4 IGBTs of each leg are removed, leaving only the diodes. This results in a topology commonly known as a Vienna rectifier. This reduces time slot utilization and can enable the model to run at a shorter simulation time step.

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.

Ports

• DC+ (electrical)
  • DC side + port.

• DCn (electrical)
  • DC side neutral port.

• DC- (electrical)
  • DC side - port.

• A (electrical)
  • AC side port - phase A
• B (electrical)
  • AC side port - phase B

• C (electrical)
  • AC side port - phase C

• gates (in)
  • Available if model control is selected
  • Vector of 12 input gate signals for switches

• En (in)
  • Available if Internal modulator/Internal modulator separated control is selected
  • Used to enable/disable internal modulator

• InA (in)
  • Available if Internal modulator/Internal modulator separated control is selected
  • Used to specify modulation signal value for internal modulator phase A

• InB (in)
  • Available if Internal modulator/Internal modulator separated control is selected
  • Used to specify modulation signal value for internal modulator phase B

• InC (in)
  • Available if Internal modulator/Internal modulator separated control is selected
  • Used to specify modulation signal value for internal modulator phase C

• Freq (in)
  • Available if Internal modulator/Internal modulator separated control is selected and Variable carrier frequency is selected as the modulator's operation mode
  • Used to specify modulator's carrier frequency

• T_junctions (in)
  • Available if Losses calculation is enabled and Temperature calculation is disabled
  • Used to provide junction temperatures for switch losses calculations
  • If the switch type is IGBT, then T_junctions consists of 24 temperature values, one for every switch and diode for all three phases
  • If the switch type is MOSFET, then T_junctions consists of 12 temperature values (MOSFET and body diode are having the same temperature)
  • If different switch type is used for Losses groups, then T_junctions consists of 18 temperature values

• T_cases (in)
  • Available if Temperature calculation is enabled
  • Used to provide case temperatures for the thermal model
  • If switch type is IGBT, then T_cases consists of 24 temperature values, one for every switch and diode for all three phases
  • If switch type is MOSFET, then T_cases consists of 12 temperature values (MOSFET and the body diode have the same temperature)
  • If different switch type is used for Losses groups, then T_cases consists of 18 temperature values

• cond_losses (out)
  • Available if Losses calculation is enabled
  • Represents conduction losses of the switching elements
  • If the switch type is IGBT, then cond_losses consists of 24 values
  • If switch type is MOSFET, then cond_losses consists of 12 values (MOSFET and the body diode have the same temperature): otherwise it consists of 18 values

• sw_losses (out)
  • Available if Losses calculation is enabled
  • Represents switching losses of the switching elements
  • If the switch type is IGBT, then sw_losses consists of 24 values
  • If switch type is MOSFET, then sw_losses consists of 12 values (MOSFET and the body diode have the same temperature): otherwise it consists of 18 values

• P_loss (out)
  • Available if both Losses and Temparature calculation are enabled
  • Represents sum of conduction and switching losses of the switching elements
  • If the switch type is IGBT, then P_loss consists of 24 values
  • If switch type is MOSFET, then P_losses consists of 12 values (MOSFET and the body diode have the same temperature): otherwise it consists of 18 values

• T_junctions (out)
  • Available if both Losses and Temparature calculation are enabled. In this case T_junctions is an output since the case thermal model is inside the component and case temperatures are provided as an input to the component.
  • Represents the junction temperatures of the switching elements
  • If the switch type is IGBT, then T_junctions consists of 24 values
  • If switch type is MOSFET, then T_junctions consists of 12 values (MOSFET and the body diode have the same temperature): otherwise it consists of 18 values

General (Tab)

• Control
  • Specifies how switches are controled. It is possible to choose between: Digital input per swich, Internal modulator, Internal modulator separated, and Model
  • More details about each type of control can be found in the Control section

• If Digital inputs per switch is selected as Control, the following properties can be used:
  • Phase A S1
    • Digital input that is used to control phase A S1 switch
  • Phase A S1 logic
    • Logic that will be applied to control signal for phase A S1
    • Active high or active low
  • Phase A S2
    • Digital input that is used to control phase A S2 switch
  • Phase A S2 logic
    • Logic that will be applied to control signal for phase A S2
    • Active high or active low
  • Phase A S3
    • Digital input that is used to control phase A S3 switch
  • Phase A S3 logic
    • Logic that will be applied to control signal for phase A S3
    • Active high or active low
  • Phase A S4
    • Digital input that is used to control phase A S4 switch
  • Phase A S4 logic
    • Logic that will be applied to control signal for phase A S4
    • Active high or active low
  • Phase B S1
    • Digital input that is used to control phase B S1 switch
  • Phase B S1 logic
    • Logic that will be applied to control signal for phase B S1
    • Active high or active low
  • Phase B S2
    • Digital input that is used to control Phase B S2 switch
  • Phase B S2 logic
    • Logic that will be applied to control signal for phase B S2
    • Active high or active low
  • Phase B S3
    • Digital input that is used to control phase B S3 switch
  • Phase B S3 logic
    • Logic that will be applied to control signal for phase B S3
    • Active high or active low
  • Phase B S4
    • Digital input that is used to control Phase B S4 switch
  • Phase B S4 logic
    • Logic that will be applied to control signal for phase B S4
    • Active high or active low
  • Phase C S1
    • Digital input that is used to control phase C S1 switch
  • Phase C S1 logic
    • Logic that will be applied to control signal for phase C S1
    • Active high or active low
  • Phase C S2
    • Digital input that is used to control Phase C S2 switch
  • Phase C S2 logic
    • Logic that will be applied to control signal for phase C S2
    • Active high or active low
  • Phase C S3
    • Digital input that is used to control phase C S3 switch
  • Phase C S3 logic
    • Logic that will be applied to control signal for phase C S3
    • Active high or active low
  • Phase C S4
    • Digital input that is used to control Phase C S4 switch
  • Phase C S4 logic
    • Logic that will be applied to control signal for phase C S4
    • Active high or active low
  • Switching enabling
    • If enabled, gives a possibility to control if changes in the gate control signal are applied or not
  • Sen
    • Available if Gate control enabling is enabled
    • Digital input that enables/disables switching
  • Sen_logic
    • Available if Gate control enabling is enabled
    • Logic that will be applied to Sen signal

• If Model is selected as Control, the following properties can be used:
  • Execution rate
    • Defines the period between two updates of gate signals for the component. Gate signals are provided as a signal processing input to component.

• If Internal modulatoror Internal modulator separated is selected as Control, the following properties can be used:
  • Operation mode
    • Specifies the source of the internal modulator carrier frequency
    • If Operation mode is Fixed carrier frequency, then frequency can be specified on the component properties
    • If Operation mode is Variable carrier frequency, then the frequency can be specified using a signal processing port
  • Carrier frequency (Hz)
    • Available if the Operation mode is a Fixed carrier frequency
    • Specifies the internal modulator's carrier frequency
  • Carrier phase offset
    • Specifies the internal modulator's carrier phase offset in degrees.
  • Dead time
    • Specifies dead time for the internal modulator in seconds
  • Reference signal [min, max]
    • If the Control is set to Internal modulator separated, this property is changeable
    • If the Control is set to Internal modulator, this property is set to [-1.0, 1.0] and cannot be changed
    • Specifies carrier signal minimal and maximal value
    • Vector containing two values: the minimal carrier signal value, followed by the maximal carrier signal value
  • Load mode
    • Specifies on which event the new value of the modulation signal will be applied in the internal modulator
      • If on min is selected, new value will be applied when carrier reaches minimal value
      • If on max is selected, new value will be applied when carrier reaches maximal value
      • If on either is selected, new value will be applied when carrier reaches minimal or maximal value
• DTV detection
  • DTV detection is not supported in TyphoonSim yet and changing its value will not affect TyphoonSim simulation at all.
  • Enables/disables dead time violation detection.
  • DTV flag is available in HIL SCADA.

Timing (Tab)

• Enable delays
  • Not supported in TyphoonSim yet, hence this signal will be zeroed. Enabling this signal will not affect TyphoonSim simulation at all.
  • Enables delays for turn on and off events

• Turn on delay
  • Specifies the delay that is applied to turn on events

• Turn off delay
  • Specifies the delay that is applied to turn off events
    • Vector consisting of current values and corresponding turn off delay. Every current value must be followed by the expected turn off delay.

Losses (Tab)

• Losses calculation
  • Enables/disables losses calculation for converter. More details can be found in the dedicated Losses calculation section.
• Losses groups
  • Available if Losses calculation is enabled
  • Specifies switch losses group: Group1or Group2

• Switch xml file1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • Used to load losses data for a switch from an xml file. More information about supported file formats can be found in the Losses calculation section.

• Diode xml file1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • Used to load losses data for the diode from an xml file. More information about supported file formats can be found in the Losses calculation section.

• Switch Group 1/2 type
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • Specifies switch type: MOSFET or IGBT. If information about switch type can be found in an xml file, it will be automatically applied.

• Current values1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • Vector of current values that are used to specify converter losses at specific points. If losses data are loaded from an xml file, it will be filled automatically.

• Voltage values1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • Vector of voltage values that are used to specify converter losses at specific points. If losses data are loaded from an xml file, it will be filled automatically.

• Temp Values1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • Vector of temperature values that are used to specify converter losses at specific points. If losses data are loaded from an xml file, it will be filled automatically.

• Vt table1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • 2D look up table for switch conduction voltage drop values. If losses data is loaded from xml file, it will be filled automatically. More information about table formats can be found in the Losses calculation section.

• Vd table1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • 2D look up table for diode conduction voltage drop values. If losses data is loaded from xml file, it will be filled automatically. More information about table formats can be found in the Losses calculation section.

• Et on table out1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • 3D look up table for switch turn on switching losses. If losses data is loaded from xml file, it will be filled automatically. More information about table formats can be found in the Losses calculation section.

• Et off table out1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • 3D look up table for switch turn off switching losses. If losses data is loaded from xml file, it will be filled automatically. More information about table formats can be found in the Losses calculation section.

• Ed off table out1/2
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • 3D look up table for diode turn off switching losses. If losses data is loaded from an xml file, it will be filled automatically. More information about table formats can be found in the Losses calculation section.

• Temperatures calculation
  • Available if Losses calculation is enabled
  • Enables/disables losses temperature calculation for converter. Thermal model must be provided. More details can be found in the dedicated Temperatures calculation section.

• Thermal networks type1/2
  • Available if Temperature calculation is enabled
  • Can be specified for both Group1 and Group2
  • Specifies the type of thermal network model: Foster or Cauer

• Rth switch1/2
  • Available if Temperature calculation is enabled
  • Can be specified for both Group1 and Group2
  • Switch thermal resistance
  • Vector

• Rth diode1/2
  • Available if Temperature calculation is enabled
  • Can be specified for both Group1 and Group2
  • Diode thermal resistance
  • Vector

• Tth switch1/2
  • Available if Temperature calculation is enabled and the Thermal network type is Foster
  • Can be specified for both Group1 and Group2
  • Switch thermal time constant
  • Vector

• Tth diode1/2
  • Available if Temperature calculation is enabled and the Thermal network type is Foster
  • Can be specified for both Group1 and Group2
  • Diode thermal time constant
  • Vector

• Cth switch1/2
  • Available if Temperature calculation is enabled and the Thermal network type is Cauer
  • Can be specified for both Group1 and Group2
  • Switch thermal capacitance
  • Vector

• Cth diode1/2
  • Available if Temperature calculation is enabled and the Thermal network type is Cauer
  • Can be specified for both Group1 and Group2
  • Diode thermal time constant
  • Vector

• Calculations execution rate
  • Available if Losses calculation is enabled
  • Can be specified for both Group1 and Group2
  • Execution rate for losses calculation. Defines interval that will be used to update losses calculation inputs and outputs.

Advanced (Tab)

• Vienna rectifier optimization
  • Vienna rectifier optimization is specific for optimization of real-time simulation and it is not applied to TyphoonSim at all. Changing its value will not affect TyphoonSim simulation at all.
  • Enables converter optimization for Vienna rectifier use. More information can be found in the Vienna rectifier optimization section.

• Model complexity
  • Model complexity is specific for real-time simulation and it is not applied to TyphoonSim at all. Changing its value will not affect TyphoonSim simulation at all.
  • Specifies model complexity: Full or Optimize resources. If 'Optimize resources' is selected, the leg will use less matrix memory in some cases, but model will be slighly simplified.The simplification is most likely to be visible in passive rectification operation.

Extras (Tab)