Sensorless Passivity Based Control of a DC Motor

In last couple of decades, the control of motors has increased drastically. With this increase, current control techniques are developed. In sensor-less passivity control of a DC Motor the term passivity means the property of stability in an input and output. To maintain the stability at the input side the solar pv panel is connected with MPPT which extract maximum and stable voltage. For output we simultaneously regulate, both, the output voltage of the SEPIC-converter to a value larger than the solar panel output voltage, and the speed of motor, in any of the turning senses, so that it tracks a prespecified constant reference. For a sensor less current control of a PMDC motor, its small-signal model that contains a number of parasitic parameters the observed current may diverge due to the parasitic resistors and the forward conduction voltage of the diode. Moreover, the divergence of the observed current will cause steady state errors in the output voltage a self-correction differential current observer (SDCO) is proposed to eliminate this steady-state error and gain high transient response speed. By carrying out a series of MATLAB simulation verifications, further investigation proves that the proposed algorithm has good robustness.