Researchers from Taiyuan University of Technology developed a novel control technology to enhance productivity of direct current (DC) electrical power
Decreasing fossil fuel and increasing demand for energy has led high adoption of renewable energy sources such as wind and solar energy. Several studies are focused on enhancing photovoltaic (PV) power generation systems that convert solar energy to electricity. However, high reliance on the irradiance and temperature conditions reduces the efficiency of direct-coupled PV systems. Continuous tracking of maximum power point (MPP) of the system at varied conditions of irradiance and temperature through maximum power point tracking (MPPT) can help to overcome the issue. DC/DC converters are commonly used in the PV power system to implement MPPT.
Series connection in PV modules helps to increase output of direct current (DC) voltage. However, the phenomenon also creates a multi-peak effect that offers hindrance in retaining equal terminal voltage across PV modules. Now, a team of researchers from Taiyuan University of Technology developed a new discontinuous pulse width modulation (DPWM) scheme in order to attain optimum control of PV inverters along with MPPT in a boost DC/DC converter. The approach is based on two-level space vector pulse width modulation (SVPWM) control technology and integrates DPWM and overmodulation to decrease device conducting periods. This helps to decrease device power losses. The overmodulation segment control method can decrease harmonic distortion of the output voltage and enhance the DC-link voltage utilization. Therefore, the approach can aid in enhancing the efficacy of the overall system.
The team found that approach is simple to implement in practical PV inverters and can be applied to other grid-tie inverters to enhance their performance. The DPWM overmodulation algorithm can decrease harmonic distortion of the three-phase output voltage and current and enhance the conversion efficiency of photovoltaic systems. The switching losses in the power electronic devices are reduced when the algorithm is implemented. The control technology helps to better utilize the DC-link voltage and effectively harvest solar energy and transform to DC electricity. The research was published in the journal MDPI Energies on May 09, 2019.