COMBINED DC-DC CONVERTER FOR USE IN HYBRID POWER SYSTEM
FIG4 is an equivalent circuit diagram of the hybrid power supply system in FIG2 in a second working mode
FIG4 illustrates an equivalent circuit diagram of the hybrid power supply system in the second working mode. As illustrated in FIG4, the controller 28 controls the bidirectional DC-DC converters 22 & 25 to work to provide pulse width modulation signals to the switch transistors Q1 & Q3, respectively raise the DC voltage at the two ends of the photovoltaic cell 21 and the rechargeable battery 24 to the predetermined DC bus voltage, and meanwhile store, in the energy storage capacitor 23, the electric energy from the photovoltaic cell 21 and the rechargeable battery 24. Since 6 KW electric energy is provided to the energy storage capacitor 23 via the bidirectional DC-DC converters 22 & 25 collectively, the bidirectional DC-DC converters 22 & 25 with lower power (e.g. 3 KW) may be selected.
diagram
28
controller
4
combined DC-DC converter
2
combined DC-DC converter
10
andFIG.
3
embodiment
['1. A combined DC-DC converter for use in a hybrid power supply system, the hybrid power supply system comprising a renewable energy power generation device, a rechargeable battery, an energy storage capacitor, and an inverter connected to the energy storage capacitor, wherein the combined DC-DC converter comprises: a first bidirectional DC-DC converter and a second bidirectional DC-DC converter, output ends of the first and second bidirectional DC-DC converters being configured to be connected to the energy storage capacitor; and a switch group configured to connect input ends of the first and second bidirectional DC-DC converters to the two ends of the renewable energy power generation device or the rechargeable battery, or respectively connect the input ends of the first and second bidirectional DC-DC converters to the two ends of the renewable energy power generation device and the rechargeable battery.', '7. The combined DC-DC converter for use in the hybrid power supply system according to any one of claims 1-6, wherein the combined DC-DC converter for use in the hybrid power supply system further comprises a controller used for controlling the on/off state of the switch group and the working mode of the first and second bidirectional DC-DC converter.']