Hardware and Software Implementation of AC Regulation Using Electromagnetic Relays

Hardware

The actual hardware of regulatory circuitry is shown in figure 1. The detail of each component used in this circuit has already been described in previous articles. 

Figure 1: Actual hardware of the regulatory circuitry

Figure 1 does not show the measuring circuit and dc converter circuit for relays. The complete setup for electromagnetic relay technique is shown in figure 2. The setup is flexible and easy to debug. Two knobs are present at the output to do power quality analysis of this technique.

Figure 2: Complete hardware setup for electromagnetic relay technique

Software

Microcontroller STM32F407 is used for the generation of control signal and sensing. Programming is done on MATLAB Simulink, compatible with the controller. Figure 3, shows the block programming done for this technique.

Description of each block used is given below:

•          Target block, setup Simulink for STM microcontroller
•          Regular ADC block is used for the sampling of analog signal to convert      it into digital signal
•           As the output put of ADC block is 16 bits’ raw data, to convert it into      meaningful value, divide its        raw value with 4096 and multiply          with the reference voltage of controller
•          Constant block is used to make constant variable of any type
•          Compare block is used to compare some value with some constant
•          NOT and AND blocks are used to implement NOT and AND logic
•          Digital output block is used to get digital output at any pin of                  controller
•      Analog signal is first converted to digital signal which is then                  compared with constants to generate desired pulses. At any instant        of time, only one pin is at digital high.

Figure 3: MATLAB (Simulink) Block Programming