[0021] The technical solutions of the present invention will be further described below in conjunction with the drawings and specific embodiments.
[0022] A PFC inductor and battery step-up transformer integrated topology, including a voltage stabilizing module and a power supply step-up module;
[0023] The voltage stabilizing module works in the mains mode, and the voltage stabilizing module provides stable positive and negative BUS voltages and correct power factor;
[0024] The power supply boost module switches to a battery-powered working state when the mains power is abnormal, and boosts the battery voltage into a stable positive and negative BUS.
[0025] Such as figure 1 with figure 2 As shown, the topology of the present invention is a front-end circuit unit of an online UPS, which aims to provide a stable positive and negative BUS power supply for the following inverter unit (a circuit that converts direct current to alternating current). The voltage stabilizing module is in the mains mode, and plays the role of stably providing positive and negative BUS voltage and power factor correction. The power supply boost module is switched to a battery-powered working state when the mains power is abnormal. Since the battery voltage is relatively low (generally between 24-72V), it is necessary to boost the battery voltage into a stable positive and negative BUS.
[0026] figure 1 The middle circuit uses BUS as the dividing line, and the mains power factor correction with TR1, M1, etc. as the core on the left, works under normal mains power supply. At this time, the booster part of the battery composed of TX1, M3, M4, etc. on the right side is not working. Conversely, when the mains power is abnormal, the battery boost part composed of TX1, M3, M4, etc. on the right starts to work, and the mains power factor correction circuit on the left with TR1, M1, etc. as the core stops working. TR1 and TX1 are the core components of these two unit circuits and are also relatively expensive components. At any time, only one of TR1 and TX1 is working, and the other is idle. The topological structure proposed by the present invention is to integrate TR1 and TX1 into an integrated design, so that two parts are combined into one part, thereby reducing costs and improving part utilization.
[0027] figure 1 The M3 and M4 form a typical push-pull power conversion circuit, but the peak energy generated by the leakage inductance of the 456 coil of TX1 cannot be completely returned to the battery through the parasitic diodes of M3 and M4, so this circuit requires a higher withstand voltage The switch tube usually takes more than 3.5 times the power supply voltage. figure 2 The M3 and M4 in the two forward power conversion circuits are cross-connected, and the parasitic diode of any one tube is used as the peak absorption circuit of the other tube. Although the peak energy generated by the leakage inductance of the 456 coil of TX1 still exists, its The peak energy can be stored in the shortest path back to the capacitor C7, and the peak voltage is also clamped to a lower potential by the capacitor C7 (the voltage of the capacitor C7 is approximately equal to the battery voltage) and then used during work. Therefore, the topological structure of the present invention has lower requirements for M3 and M4, usually 2.5 times the power supply voltage.
[0028] To further illustrate, the voltage stabilizing module includes diodes D2, D3, D4, D5, D6, D7, D8, D9, D11 and D13, coupled inductors TL1, TL2, inductors LR1, LR2, MOS transistors M1, capacitors C1, C2 and current detection element RS1;
[0029] One end of the diode D2 is connected to the diode D5, the diode D8 is connected in parallel with the capacitor C1 and then connected in series with the diode D5, one end of the diode D8 is connected to the inductor LR1, and one end of the inductor LR1 is connected to One end of the coupled inductor TL1 is connected to the diode D3, one end of the diode D4 is connected to the diode D3, and the other end of the diode D4 is connected to one of the diode D9 and the diode D11. In between, one end of the diode D11 is connected to the capacitor C2, one end of the branch after the diode D6 and the diode D7 are connected in series is connected to the diode D8, and the other end is connected to the diode D13. One end of the diode D13 is connected between the capacitor C2 and the diode D11, the other end of the diode D13 is connected to the inductor LR2, one end of the inductor LR2 is connected to the coupled inductor TL2, and the MOS transistor M1 The gate is connected to the driving pulse of the circuit, the drain and source of the MOS transistor M1 are respectively connected to the inductor LR1 and one end of the current detection element RS1, and the other end of the current detection element RS1 is connected to the inductor LR2 .
[0030] To further illustrate, the power supply boost module includes a MOS tube M3, a MOS tube M4, a coupled inductor TL3, a coupled inductor TL4, and a capacitor C7;
[0031] The MOS transistor M3, the coupled inductor TL3, the MOS transistor M4, and the coupled inductor TL4 form a closed series loop, and both ends of the capacitor C7 are connected to the MOS transistor M3 and the MOS transistor M4, respectively.
[0032] To further illustrate, the capacitor C1 is an electrolytic capacitor.
[0033] To further illustrate, the capacitor C2 is an electrolytic capacitor.
[0034] To further illustrate, the current detection element RS1 is a resistor or other element capable of detecting current.
[0035] figure 2 Among them, RS1 is a current detection element, which can be any type of element that can detect current, and is not limited to the form of resistance.
[0036] To further illustrate, one end of the current detection element RS1 is connected to the sensing end of the circuit, and the other end of the current detection element RS1 is connected to the ground end of the circuit.
[0037] To further illustrate, one end of the diode D2 is connected to the live wire of the alternating current.
[0038] To further illustrate, the diode D3 and the diode D4, the diode D6 and the diode D7, the capacitor C1 and the capacitor C2 are respectively connected to the neutral line of the alternating current.
[0039] The technical principle of the present invention has been described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention, and cannot be construed as limiting the protection scope of the present invention in any way. Based on the explanation here, those skilled in the art can think of other specific implementation manners of the present invention without creative work, and these manners will fall within the protection scope of the present invention.
