I would like to design and develop a control system based on FPGA ALTERA DE0, this system control a bridge inverter with PWM technique, I need to sens the load current and control it at thier reference.
The DE0 board seems not to have analog inputs. Therefore you have to attach a suitable external ADC (analog to digital converter) to the DE0 expansion connector. There are ADC modules with SPI interface around.
Your bridge should provide a voltage measurement signal which is proportional to the load current. If not, you have to provide a suitable shunt resistor for the purpose and measure the voltage drop over the shunt.
Attention: There may be higher voltages in your bridge than the DE0 or an ADC (or a human) can tolerate. Careful design of measurement circuit is necessary!
Dear Nabil;
Altera board doesn't have direct capabilities to operate with the power electronics of the bridge inverter. It is a good idea to have a digital to analog converter to convert the signal and power associated switching relays. Please, carefully check power flow in the system, as you can easily burn DA converter and Altera board, if you connect it directly to the power line- current and voltage levels should be carefully calculated.
Overall, you should consider separate design for the power-related signals and Altera signals, combined with the sensors for the control system, if necessary.
FPGA's accept only digital format data types. Attenuate the signals as per the voltage level of ADC. I would recommend using the control algorithm in the DSP and generating the gate signals in the FPGA. Prefer model based design in the Simulink platform.
Why did you decide to use the FPGA? This approach involves the use of additional analog converters to control current and voltage. Many microcontrollers with a multiphase generator are available. For example, Atmel AT90PWM3 microcontroller with integrated PSC controller and analog comparator to control the inverter current level.
I decided to use FPGA plateform because I could for example regulate a reference current with high frequency. For this, a very high swithing frequency is required
At what frequency do you plan to use the inverter? Typical frequency of drive inverters is 8-16 kHz. The microcontroller in the previous message copes with the regulation. It is designed for this purpose. A further increase in the conversion frequency will lead to additional dynamic losses in the inverter and an increase in dynamic losses in the motor if it operates without an output filter.
I'd like to operate the inventer at 40-50 kHz, I use a SIC power devices
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