**7.2 Microprocessor simulation**

344 Grid Computing – Technology and Applications, Widespread Coverage and New Horizons

Fig. 16. Circuit schematic of inverter power supply

Fig. 17. PWM model in the MTU microprocessor unit

The modulation ratio, the carrier frequency, the reference frequency were changed

m = VC /Vcarrier (1)

manually. Equation (1) describes the relation among all three parameters.

In the inverter power supply applications, the microprocessor is used to control the switching period of the transistors as a digital controller. This microprocessor has two main units which are used to control both the DC/DC and DC/AC stages of the inverter power supply. Each unit is controlled by a software program; this embedded software function can be divided into two main parts which are the control program (control algorithm) and the PWM generation program.
