JP2000184743A - Inverter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voltage doubler half bridge inverter of a high power factor. SOLUTION: A sub-half bridge type inverter having sub-capacitors 41, 42 as capacitor arms and switching elements 51, 52 as switching arms is formed, and an inductive load 90 to be an AC load is connected. An auxiliary inductor 33 connected to a position as an AC load of a main half bridge type inverter through an inductive load 90 is provided, and a rectifying power source 10 is connected in parallel with the arms of main capacitors 21, 22. A terminal of an AC power source 11 of the power source 10 is connected to a connecting point of the inductor 33 to the load 90. Auxiliary diodes 31, 32 are disposed to allow discharging of the capacitors 21, 22 to the capacitors 41 42 and to inhibit discharging from the latter to the former between the capacitors 21, 22 and the capacitors 41, 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage doubler type half-bridge type inverter device. In particular, it relates to a high power factor.

[0002]

2. Description of the Related Art A general double voltage type half-bridge type inverter device shown in FIG. 10 will be described. FIG.
The 0 device includes a rectified power supply 10 for rectifying an AC power supply 11 voltage. A large-capacity pair of main capacitors 21 and 22 are provided. It has a pair of switching elements 51 and 52 in a forward series controlled to be turned on and off alternately. It has flywheel diodes 61 and 62 connected in anti-parallel with the respective switching elements 51 and 52. Each main capacitor 21
22 is a capacitor arm and each switching element 51
Form a main half-bridge inverter with 52 as a switch arm. The main half-bridge inverter includes an inductive load 90 serving as an AC load. The rectified power supply 10 is connected in parallel with a capacitor arm composed of the main capacitors 21 and 22. The AC power supply terminal of the rectified power supply 10 is wired to a connection midpoint between the main capacitors 21 and 22. Rectifier power supply 10
14.1 of the rectifying diodes 12 to 15 belonging to
5 can be omitted.

[0003]

The voltage of each of the main capacitors 21 and 22 in FIG. 10 is approximately equal to the maximum value of the AC power supply 11 voltage, which is approximately equal to the inductive load 90 voltage. For this reason, a high inductive load 90 voltage comparable to a full bridge type (bridge type in which the capacitor arms 21 and 22 are switch arms not shown) inverters is obtained despite being a half bridge type. The AC power supply 11 (power supply from the AC power supply 11) in FIG.
This is done only for a very short period (phase) when one voltage (instantaneous value) exceeds the voltage of the main capacitor (21 or 22). For this reason, it is a low power factor type. SUMMARY OF THE INVENTION It is an object of the present invention to provide a high power factor increasing means suitable for a voltage doubler type half-bridge type inverter device.

[0004]

According to the present invention, there is provided a rectified power supply for rectifying an AC power supply voltage. It has a large-capacity pair of main capacitors. It has a pair of auxiliary diodes. It has a pair of small capacitors in series. It includes a pair of switching elements in a forward series controlled to be turned on and off alternately. A flywheel diode connected in antiparallel with each of the switching elements. A sub-half-bridge inverter is formed in which each sub-capacitor is a capacitor arm and each switching element is a switch arm. An inductive load serving as an AC load of the sub half-bridge inverter is provided. A main half-bridge type inverter having each of the main capacitors as a capacitor arm and each of the switching elements as a switch arm is formed. An auxiliary inductor is connected to the main half-bridge inverter at a position to be an AC load via the inductive load. The rectified power supply is connected in parallel with a capacitor arm of each of the main capacitors. An AC power supply terminal of the rectified power supply is connected to a connection point between the auxiliary inductor and the inductive load. Each of the auxiliary diodes is arranged between each of the main capacitors and the corresponding sub-capacitor so as to allow discharge from the former to the latter and prohibit discharge from the latter to the former.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An inverter device according to the present invention shown in FIG. 1 will be described. 1 includes a rectified power supply 10 for rectifying an AC power supply 11 voltage. A large-capacity pair of main capacitors 21 and 22 are provided. A pair of auxiliary diodes 3
1 ・ 32. A pair of small capacitors 4 in series
1.42. It has a pair of switching elements 51 and 52 in a forward series controlled to be turned on and off alternately. Flywheel diodes 61 and 62 are connected in anti-parallel with the switching elements 51 and 52, respectively. A sub half-bridge inverter is formed in which each of the sub capacitors 41 and 42 is a capacitor arm and each of the switching elements 51 and 52 is a switch arm. An inductive load 90 serving as an AC load of the sub half-bridge inverter is provided. A main half-bridge type inverter having the main capacitors 21 and 22 as capacitor arms and the switching elements 51 and 52 as switch arms is formed. An auxiliary inductor 33 is provided at a position to be an AC load of the main half-bridge type inverter via the inductive load 90. The rectified power supply 10 is connected in parallel with a capacitor arm composed of the main capacitors 21 and 22. An AC power supply 11 terminal of the rectified power supply 10 is connected to a connection point between the auxiliary inductor 33 and the inductive load 90. The auxiliary diodes 31 and 32 are arranged between the main capacitors 21 and 22 and the corresponding sub-capacitors 41 and 42 so as to allow discharge from the former to the latter and inhibit discharge from the latter to the former. . FIG. 1 is supplemented. The rectification power supply 10 includes rectification diodes 12 to 15. It is desirable to have a filter circuit (not shown) for reducing high-frequency component current passing through the AC power supply 11. The rectifying diodes 14 and 15 can be omitted. The main capacitors 21 and 22 have relatively large capacities, and the sub-capacitors 41 and 42 have relatively small capacities. It is convenient to distinguish the main capacitors 21 and 22 or the sub capacitors 41 and 42 or the main and sub capacitors such as the main half-bridge type inverter and the sub-half bridge type inverter. Each of the sub-capacitors 41 and 42 forms a sub-half-bridge type inverter having the switching elements 51 and 52 as companions. Each of the main capacitors 21 and 22 forms a main half-bridge type inverter having the switching elements 51 and 52 as companions. The AC load of the main half-bridge type inverter is a series circuit of the auxiliary inductor 33 and the inductive load 90. The term half bridge refers to a bridge formed by two switches and two capacitors. Incidentally, the four-switch bridge is a full bridge. Rectified power supply 10 and main capacitors 2
The circuit configurations of No. 1 and No. 22 are such that voltage doubler rectification can be performed via the auxiliary inductor 33. The AC power supply 11 terminal of the rectified power supply 10 is a midpoint between the positive electrode and the negative electrode. The flywheel diodes 61 and 62 play a role of releasing electromagnetic energy stored in the inductive load 90. Auxiliary diode 31
32 plays a role of increasing the voltage of the sub capacitors 41 and 42. The illustrated inductive load 90 is a lighting circuit, and includes a discharge lamp (fluorescent lamp) 91, a ballast inductor 92 in series with the discharge lamp 91, and a preheating capacitor 9 in parallel with the discharge lamp 91.
2 inclusive. It is equivalent to connect a large-capacity capacitor (not shown) at a position straddling the main capacitors 21 and 22. Under such circumstances, removing one of the main capacitors 21 and 22 is equivalent. For example, when the main capacitor 21 is removed, the main capacitor becomes a series circuit (composite capacitor) of the large capacity capacitor and the main capacitor 22 (not shown). The same is true for the sub capacitors 41 and 42. The double capacitors are charged to the main capacitors 21 and 22 in FIG. At this time, the auxiliary inductor 33 acts to alleviate the rapid charging (charging mode that forms an excessive charging current). In this situation, the inverter operation starts. The basic operation of the inverter is the on / off of the switching elements 51 and 52 and the flywheel diodes 61 and 62. Only one of them is turned on, and the order of the turned on is 51.
→ 62 → 52 → 61 → 51... The on period of the switching elements 51 and 52 is a period during which electromagnetic energy is accumulated in the inductive load 90, and the flywheel diode 61
The ON period of 62 is a period in which the stored electromagnetic energy is released. The on period of the switching element 51 and the flywheel diode 62 is a period for forming a current of the left inductive load 90, and the on period of the switching element 52 and the flywheel diode 61 is a period for forming the right inductive load 90.
This is a period for forming a current. These operations are general. The operation will be described with reference to FIGS.
The current (1) in FIG. 2, the current (2) in FIG.
It operates in the order of 1). The operation of the current (11) in FIG.
The operation is the same as that of the current (1), and the following is the repetitive operation. The voltage polarity of the AC power supply 11 is as shown in the figure, but the operation when the polarity is opposite to that is almost the same (more precisely, symmetric operation). Also, for example, the current (1)
Although there is a transitional period in which (2) is formed at the same time, their illustration is omitted. The following is a supplementary explanation. Period of current (1): The discharge of the main capacitor 21 is suppressed because the voltage of the sub capacitor 41 is relatively high and the voltage of the main capacitor 21 is relatively low, and because of the delay effect of the auxiliary inductor 33. Period of current (2): Main capacitor 21 is discharged. The electromagnetic energy is stored in the inductive load 90 and the auxiliary inductor 33. Period of current (3) (4) (5): Current (3) (4)
The operation (5) proceeds almost simultaneously and in parallel. Current (3)
Forms a high voltage on the sub-capacitor 42. The current (4) increases the voltage of the sub capacitor 41. The current (5) prompts the supply of the rectified power supply 10 and charges the main capacitor 22. Period of current (6): The discharge of the main capacitor 22 is suppressed because the voltage of the sub capacitor 42 is relatively high and the voltage of the main capacitor 22 is relatively low, and because of the delay effect of the auxiliary inductor 33. This situation continues until the voltage of the sub capacitor 42 decreases and becomes equal to the voltage of the AC power supply 11. Period of current (7): Rectifying power supply 10 is supplied. Due to the delay effect of the auxiliary inductor 33, the discharge of the main capacitor 22 is still suppressed. Switching element 52
, The inductive load 90 at this time exceptionally emits electromagnetic energy. Period of current (8): Main capacitor 22 is discharged. The electromagnetic energy is stored in the auxiliary inductor 33 and the inductive load 90. The current (7) is a current affected by the voltage (instantaneous value) of the AC power supply 11, and is unstable in that sense. The current (8) is a stable current supplied from the main capacitor 22 that holds a substantially constant voltage, and
It contributes to stabilization of current. Period of currents (9) and (10): The current (9) forms a high voltage on the sub-capacitor 41. The current (10) increases the voltage of the sub capacitor 42. Since the voltage of the AC power supply 11 has a polarity opposite to the direction of the current (10), power supply to the rectified power supply 10 does not occur. Period of current (11): Current (11) is current (1) in FIG.
The following is the repetitive operation. When the voltage of the AC power supply 11 has a polarity opposite to that shown in the figure, the operation shifts to a symmetric operation.

[0009]

According to the present invention, the main features are a sub capacitor, an auxiliary inductor, an auxiliary diode and the like. According to this, it is possible to obtain a double-voltage half-bridge type inverter device that operates at a high power factor.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an inverter device according to the present invention.

FIG. 2 is a circuit diagram illustrating the operation of FIG.

FIG. 3 is a circuit diagram illustrating the operation of FIG.

FIG. 4 is a circuit diagram illustrating the operation of FIG.

FIG. 5 is a circuit diagram illustrating the operation of FIG.

FIG. 6 is a circuit diagram illustrating the operation of FIG.

FIG. 7 is a circuit diagram illustrating the operation of FIG.

FIG. 8 is a circuit diagram illustrating the operation of FIG.

FIG. 9 is a circuit diagram illustrating the operation of FIG. 1;

FIG. 10 is a circuit diagram showing a conventional inverter device.

[Explanation of symbols]

 10: Rectified power supply 11: AC power supply 21 ・ 22: Main capacitor 31 ・ 32: Auxiliary diode 33: Auxiliary inductor 41 ・ 42: Sub capacitor 51 ・ 52: Switching element 61 ・ 62: Flywheel diode 90: Inductive load

Claims (1)

[Claims] A rectifying power supply for rectifying an AC power supply voltage;
A large-capacity series pair of main capacitors, a pair of auxiliary diodes, a small-capacity series pair of sub-capacitors, and a pair of forward-series switching elements controlled to be turned on and off alternately; A flywheel diode connected in anti-parallel with the switching element, forming a sub-half-bridge type inverter having each of the sub-capacitors as a capacitor arm and each of the switching elements as a switch arm, and an AC load of the sub-half-bridge type inverter; Forming a main half-bridge inverter having each main capacitor as a capacitor arm and each switching element as a switch arm, wherein the inductive load is provided at a position to be an AC load of the main half-bridge inverter. And an auxiliary inductor connected through The rectified power supply is connected in parallel with the capacitor arm of each main capacitor, the AC power supply terminal of the rectified power supply is connected to a connection point between the auxiliary inductor and the inductive load, and each of the main capacitors and the corresponding sub-capacitor are connected. Wherein the auxiliary diodes are arranged so as to allow discharge from the former to the latter and prohibit discharge from the latter to the former.