A coordinated control method for static PV model fed pump motor system under rapid irradiation drop

초록

Photovoltaic (PV)-fed motor pump system employs an advanced system that eliminates the need for batteries to reduce maintenance and equipment costs during the day in desert areas. Real-time adjustment of the motor output speed stops the motor from drawing power from a storage capacitor in the DC link so that sensors and microcontrollers (MCU) do not lose power and restart. This paper proposes an extremum seeking control (ESC) to achieve high accuracy of the maximum power point tracking (MPPT) algorithm by improving the accuracy of current and voltage measurements. MPPT-based motor speed vector control rule is proposed. A field-oriented control (FOC) scheme and sensorless direct torque control (DTC) scheme are introduced for comparison. The control method and interior permanent magnet synchronous motor (IPMSM) are tested on the PV simulator and dynamometer experimental test-rig. The test results show that the sensorless DTC can regulate the motor speed and torque to the desired value without system power failure. In contrast, the speed fluctuation of FOC control is lower than sensorless DTC. However, the system tuning time of DTC is faster and easy to support the whole system operation. The main technical contribution of this study is to provide a coordinated control method to maintain the continuous operation of the entire system during the daytime.

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