PWM

in the palette on the schematic

The block is used in the BDCM and implements PWM modulation inside the pulses coming from the selector of the inverter keys.

The figure below explains the dependency between the parameters of the triangular PWM reference signal and the values set in the block properties (Figure 1).


Figure 1. PWM triangular reference signal parameters

The six-channel signal "PWM" manages the IGBT bridge keys. The distribution of the output signals (VT1...VT6) when controlling the half-bridges of the three-phase inverter is shown in the figure (Figure 2).



Figure 2. Distribution of output signals

The block allows you to implement three types of PWM modulation:

PWM 1 (Figure 3):
  • It can be used with sufficiently large winding inductances.
  • The reactive currents are closed through the inverter power supply.


Figure 3. Type of PWM signals for the "PWM - 1" circuit
PWM 2 (Figure 4):
  • Provides minimum current pulsations in the motor windings.
  • Reactive currents are closed through the motor windings and inverter diodes.
  • It provides a minimum of losses in the lower keys of the inverter.


Figure 4. Type of PWM signals for the "PWM - 2" circuit
PWM 3 (Figure 5):
  • It can be used for bootstrap power supply of inverter key drivers.
  • Provides minimum current pulsations in the motor windings.
  • Reactive currents are closed through the motor windings and the inverter keys.


Figure 5. Type of PWM signals for the "PWM - 3" circuit

Inputs

Parameter Description Communication line type
U Modulated signal Mathematical
S Six-channel signal input from BDCM key selector Mathematical

Outputs

Name Description Communication line type
PWM Six-channel control signal of the IGBT bridge keys Mathematical

Properties

Name Name Description Default value Data type
Maximum value of the reference signal, ([V] or [r.u.]) max Maximum PWM reference triangle value 1 Вещественное
Minimum reference signal value min Minimum PWM reference triangle value -0.0037 Вещественное
Period, s Tpwm PWM period 5E-5 Вещественное
Protective pause time, s tz Inverter rack keys ON protection pause time 1E-6 Вещественное
PWM diagram mode PWM type selection The possible values are:
  • “PWM 1";
  • “PWM 2";
  • “PWM 3"
 PWM 1 Перечисление

Parameters

The block has no parameters.

Examples

Examples of block application:
  • Position of the BDCM