The invention provides an apparatus for integrating low voltage Photovoltaic (PV) power with three-phase AC power. The apparatus includes a three-phase transformer with a zigzag secondary winding, an AC to DC converter, a DC bus capacitor, and a three-phase control circuit. The zigzag transformer integrates PV voltage with three-phase AC to produce an AC superimposed DC voltage. The AC to DC converter then converts this voltage to DC. The control circuit maintains a predefined reference DC bus voltage, ensuring stable power delivery to the DC bus capacitor and any connected loads. This method offers efficient integration of PV power with three-phase AC systems.
Figure (1) It illustrates voltage source current controlled Pulse Width Modulation (PWM) rectifier circuit, according to prior art; (2) It illustrates the proposed apparatus, according to embodiments as disclosed herein.
- The current challenge in integrating photovoltaic (PV) energy with three-phase AC voltage systems lies in the need for dedicated converters to extract and feed PV energy to a common bus. These converters significantly increase the overall cost, size, and weight of the system.
- Moreover, the conventional power transfer, which relies on single-frequency form, demands high voltage boosting.
- There is a need for developing converter topologies and control methods that facilitate multi-frequency power transfer, allowing AC superimposed DC voltage and current, thereby improving the efficiency and cost-effectiveness of integrated PV-based systems.
- Integration of Low Voltage PV Power: The apparatus integrates low voltage photovoltaic (PV) power with three-phase AC power without requiring complex high-gain DC-DC converters, simplifying the overall system design and increasing efficiency.
- Reduced Size, Weight, and Cost: By using transformer leakage inductance as inductance between the source and the AC to DC converter, the system reduces the size, weight, and cost of magnetic components in the Variable Frequency Drive (VFD) system.
- Avoidance of Transformer Core Saturation: The zigzag connection in the secondary winding of the transformer prevents core saturation due to DC current, enhancing the reliability and efficiency of the system.
- High-Frequency Transformer Benefits: The inclusion of a High-Frequency (HF) transformer in the Dual Active Bridge (DAB) converter stage in the Solid State Transformer (SST) reduces the size and weight significantly compared to traditional transformers.
- Enhanced Control and Stability: The three-phase control circuit maintains a predefined reference DC bus voltage, ensuring stable and efficient power conversion and delivery to the load.
A working prototype of the proposed apparatus has been developed. This includes the integration of a three-phase transformer with a zigzag connection, AC to DC converter, DC bus capacitor, and three-phase control circuit.
Detailed simulation models have been created to analyze the performance of the proposed apparatus. These models simulate various scenarios, including different PV power outputs, grid conditions, and load demands.
Working prototype has been developed, including key components such as the zigzag-connected transformer, AC to DC converter, DC bus capacitor, and control circuit. Detailed simulation models have been created to evaluate its performance under different conditions. The technology is also available for licensing
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- It enhances renewable energy integration, leading to reduced greenhouse gas emissions and a cleaner environment.
- Applications include residential and commercial solar power systems, electric vehicle charging stations, and smart grids, improving energy efficiency and accessibility.
- By decreasing the size, weight, and cost of power conversion components, it makes advanced energy solutions more affordable and widespread.
Applications include residential and commercial solar power systems, electric vehicle charging stations, and smart grids, improving energy efficiency and accessibility.
Geography of IP
Type of IP
201721015209
470974