JP3389834B2 - DC power supply - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chopper-operated DC power supply incorporating a chopper inductor / chopper switch. 2. Description of the Related Art FIG. 2 shows a known circuit in which an inverter device 200 is connected to a stage subsequent to a DC power supply device 100. FIG. 2 will be described. The DC power supply 100 includes a rectified power supply 36 for rectifying the voltage of the AC power supply 10. 32 to 35 are rectifying diodes belonging to the rectifying power supply 36. A chopper inductor 20 and a chopper switch 31 for intermittently applying a rectified power supply 36 voltage to the chopper inductor 20 are provided. The chopper switch 31 is a transistor,
A control circuit (not shown) for appropriately switching it is attached. Reverse blocking diode 53 that emits electromagnetic energy stored in chopper inductor 20 and smoothing capacitor 4 that is charged by receiving the output of reverse blocking diode 53
3 is provided. The inverter device 200 is of a half-bridge type in which a pair of capacitors 44 and 45 and a pair of inverter switches 61 and 62 are connected in a bridge shape, and an inverter load 80 is connected between connection points of the paired elements. 71 and 72 are inverter switches 61 and 62
And a flywheel diode connected in anti-parallel.
Consider the position of the chopper switch 31 in the DC power supply 100. The chopper switch 31 has a rectifier circuit 32 to
It is arranged after 35. In this sense, it is a switch type configuration after rectification. [0005] The voltage of the smoothing capacitor 43 shown in FIG. 2 is applied to the chopper switch 31 when the reverse blocking diode 53 is on. Chopper switch 31
, A high voltage corresponding to the output voltage of the DC power supply device 100 is applied. It threatens the pressure resistance of the chopper switch 31.
Also, a large switching loss is generated. An object of the present invention is to reduce the withstand pressure load of a chopper switch. [0004] The device of the present invention includes an AC power supply. A chopper inductor is provided. An AC operation type chopper switch for intermittently applying an AC power supply voltage to the chopper inductor is provided. A first smoothing capacitor and a second smoothing capacitor are connected in series. A first auxiliary diode for applying a positive voltage of the AC operation type chopper switch to the first smoothing capacitor; A second auxiliary diode for applying a negative voltage of the AC operation type chopper switch to the second smoothing capacitor; The first smoothing capacitor, the second smoothing capacitor, the first auxiliary diode, and the second auxiliary diode form a voltage doubler rectifier circuit. The AC-operated chopper switch is arranged in front of such a voltage doubler rectifier circuit. This is a switch-type configuration before rectification. Therefore, the withstand pressure load of the AC operation type chopper switch is reduced. An embodiment of the present invention will be described with reference to FIG. In this description, the part numbers in FIG. 2 are used as much as possible, and a part of the overlapping description is omitted. The DC power supply device 100 according to the present invention shown in FIG. A chopper inductor 20 is provided. An AC operation type chopper switch 30 for intermittently applying a voltage of the AC power supply 10 to the chopper inductor 20 is provided. A first smoothing capacitor 41 and a second smoothing capacitor 42 are connected in series. A first auxiliary diode 51 for applying a positive voltage of the AC operation type chopper switch 30 to the first smoothing capacitor 41 is provided. A second auxiliary diode 52 for applying the negative voltage of the AC operation type chopper switch 30 to the second smoothing capacitor 42 is provided. The AC operation type chopper switch 30 is obtained by converting the characteristics of the unidirectional switch 31 into bidirectional characteristics using a rectifier circuit including diodes 32-35. Unidirectional switch 31
Is a transistor. The first smoothing capacitor 41 and the second smoothing capacitor 42 are the capacitor arms of the half-bridge inverter device 200 (two sides of the bridge circuit).
Doubles. The operation during the period in which the AC power supply 10 voltage is positive is as follows. When the AC operation type chopper switch 30 is turned on, a current flows through a closed circuit of 10-30-20-10, and electromagnetic energy is accumulated in the chopper inductor 20. When the AC operation type chopper switch 30 is turned off, 2
The closed circuit of 0-10-51-41-20 is energized, the electromagnetic energy of the chopper inductor 20 is released, and the first smoothing capacitor 41 is charged. The operation during the period when the voltage of the AC power supply 10 has the negative and positive polarity is as follows. When the AC operation type chopper switch 30 is turned on, 10-20-30-
When the closed circuit 10 is energized, electromagnetic energy is stored in the chopper inductor 20. AC operation type chopper switch 3
When 0 is turned off, the closed circuit of 20-42-52-10-20 is energized, the electromagnetic energy of the chopper inductor 20 is released, and the second smoothing capacitor 42 is charged. A first smoothing capacitor 41, a second smoothing capacitor 42, a first auxiliary diode 51, and a second auxiliary diode 52 are operated by receiving an AC voltage formed across the AC-operated chopper switch 30. Configure the circuit. The AC operation type chopper switch 30 is arranged in front of the voltage doubler rectifier circuits 41, 42, 51, 52. This is a switch-type configuration before rectification. FIG. 2 shows a switch type after rectification. In the present invention, the switch type after rectification is changed to a switch type before rectification. The present invention is particular about this difference. The voltage applied to the chopper switch 30 is a double voltage in the case of the switch type after rectification, and is a single voltage half that in the case of the switch type before rectification. The present invention is the latter, and performs a single-voltage switch operation, so that the withstand pressure load of the chopper switch 30 is reduced. Also, the switching loss of the chopper switch 30 is reduced. The output voltage of the DC power supply 100 is the voltage across the first smoothing capacitor 41 and the second smoothing capacitor 42 and is a doubled voltage. When the first auxiliary diode 51 or the second auxiliary diode 52 is on, the voltage of the first smoothing capacitor 41 or the second smoothing capacitor 42 is applied to the AC operation type chopper switch 30. It is a single voltage of output voltage / 2. The voltage applied to the AC-operated chopper switch 30 in the course of turning off is a low-level single voltage. Therefore, the turn-off loss is reduced. Depending on the operation mode, the AC operation type chopper switch 30 may be turned on before the first auxiliary diode 51 or the second auxiliary diode 52 is turned off. In this case, the voltage of the first smoothing capacitor 41 or the voltage of the second smoothing capacitor 42 is turned on through the first auxiliary diode 51 or the second auxiliary diode 52 whose reverse blocking characteristic is being recovered, and the AC operation type chopper is being turned on. Apply to switch 30. It causes an increase in turn-on loss. However, the operating voltage in this case of the present invention is not a double voltage but a single voltage. Therefore, the turn-on loss is also reduced. According to the present invention, an AC-operated chopper switch is provided in a stage preceding a voltage doubler rectifier circuit. According to this, the withstand pressure load of the AC operation type chopper switch is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of the device of the present invention. FIG. 2 is a circuit diagram of a conventional device. [Description of Signs] 10: AC power supply, 20: Chopper inductor, 30:
AC operation type chopper switch, 41: first smoothing capacitor, 42: second smoothing capacitor, 51: first auxiliary diode, 52: second auxiliary diode, 100: DC power supply device, 200: inverter device

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02M 7/5387 H02M 7/06

Claims (1)

(1) An AC power supply (10) , a chopper inductor (20) is provided, and a voltage of the AC power supply (10 ) is intermittently supplied to the chopper inductor (20). An AC-operated chopper switch (30) to be applied, a first smoothing capacitor (41) and a second smoothing capacitor (42) connected in series, and a positive polarity voltage of the AC-operated chopper switch (30). The first smoothing capacitor
Comprising a first auxiliary diode to be applied to (41) (51), a second auxiliary diode for applying a negative voltage of the AC operating type chopper switch (30) to the second smoothing capacitor (42) (52) A DC power supply device comprising: