Complex Impedance Matching for Electromagnetic Vibration Energy Harvesting: Key Parameters and Low Power Consumption Implementation
Zhijie Feng, Han Peng, Yong Kang
Abstract
Complex impedance matching of electromagnetic vibration energy harvesting (EMVEH) will have maximum power delivery under complex impedance matching. However, state of the arts on complex impedance matching suffered from complex implementation, high control loss, and no improvement of output power compared with conventional resistive matching. To overcome these limitations, the implementation of complex impedance matching with low power consumption and significant output power improvement is proposed in this article. The power improvement effect of complex impedance matching is established and the critical parameters affecting the improvement are derived. The influence of the coil on the control realization, the selection of the power transistor is analyzed. The hardware implementation of complex impedance matching circuit with low power consumption is also proposed. The design prototype of EMVEH achieves 65 mW under resonance at 0.3 g. Compared with resistance matching, the max. extraction power of the harvester is increased by 22.7 mW, and the total loss of the system is only 10 mW. It is demonstrated that output power of the harvester over the wide frequency range is significantly enhanced with low controller loss under complex impedance matching.