High Frequency Dual-Buck Full-Bridge Inverter Utilizing a Dual-Core MCU and Parallel Algorithm for Renewable Energy Applications

Abstract

Abstract:A high frequency dual-buck full-bridge inverter for small power renewable energy applications is proposed in this paper. The implementation of the wide band gap SiC (Silicon Carbide) power device contributes to the high switching frequency of 400 kHz. This high frequency contributes to reduced converter volume as well as improved power density, which greatly strengthens its portability and application range. For the control strategy, a voltage-current dual loop controller is employed. A three-pole-three-zero (3P3Z) compensator is applied in the current loop in order to track the current reference without static error. A voltage loop two-pole two-zero (2P2Z) compensator is used to generate the current reference for stabilizing the DC bus voltage. Not only is the inner current loop analyzed in detail, which includes the modeling of the equivalent inductor-capacitor-inductor (LCL)-type inverter and the design of the 3P3Z compensator, but also the outer voltage loop is discussed, the model of which is established based on the energy balance. Furthermore, a feedback linearization method is adopted to simplify the duty cycle calculation and helps to accelerate the control speed. A second-order generalized integrator software phase lock loop (SOGI-SPLL) is employed to obtain the phase angle and to synchronize the inverter output current with the grid voltage. A parallel structure algorithm is conducted based on a dual-core microcontroller unit (MCU) for the first time to control the high frequency inverter. This approach avoids the contradiction between the high frequency operation and the limited computing capacity of the conventional single-core MCUs. The software structure, time-consuming distribution, and interactive communication method are analyzed in detailed. Finally, this paper verifies the feasibility of the theoretical analyses through simulation and experiments based on a 1 kW prototype.

Parameters Design and Optimization of a High Frequency, Interleaved, Dual-Buck, Bidirectional, Grid-Connected Converter

“…The minimum value of Cf is at point B, which corresponds to a value of 0.4 uF. A smaller range of Cf can be obtained as shown in (17). Similarly, from Figure 12, it can be seen that K can meet the requirements of resonant frequency fres in the range of 3-7, so the range of K is still 3-7.…”

“…The minimum value of C f is at point B, which corresponds to a value of 0.4 uF. A smaller range of C f can be obtained as shown in (17).…”

“…Moreover, a series of research work about the design method of filter parameters has been carried out. In references [16,17], the inductance and capacitance of the filter were obtained by preset ripple, reactive power limitation, and resonant frequency. The design method was simple, feasible, and easy to calculate.…”

Extension of Zero Voltage Switching Capability for CLLC Resonant Converter

“…Recently, the small sized power converterhas become significant in various industries, such as lightings, TVs, computers, and other home appliances [1,2]. A power converter operating at a high switching frequency is one effective method to improve power density [3][4][5][6][7]. However, the high switching frequency operation induces a large switching loss for the turn-on and turn-off states.…”

A Digitally Controlled Power Converter for an Electrostatic Precipitator

“…Its differential gain is 31.25·10 −6 and it presents a high-frequency pole at 4 kHz to The authors in a previous work [33] performed the control of the converter with an analog control, C(jω). In this work, the design of the digital feedback loop [35,36] is based on classical control theory and small signal analysis (Figure 11). Other techniques based in digitally controlled power converter based on DSP [10] could be used always.…”