JPS60245471A - Inverter device - Google Patents

Abstract

PURPOSE:To obtain a 3-phase output power source by a single-phase power source by converting a phase directly to a load with a single phase AC input power source as the first phase and the first phase to the phase by a phase converter as the second phase by connecting to the load. CONSTITUTION:A single phase AC input voltage waveform E1 applied between terminals (u) and (v) receives a phase converting switching pulse waveform PWM control to generate an output voltage waveform E2 converted at 120 in phase between terminals V and W as positive half wave. The output voltage waveform E1 having the same waveform as the input voltage waveform E1 is combined with the output voltage waveform E2 at the output terminals U, V and W to form 3-phase output power source from the output voltage waveforms E1, E2 and E3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inverter device that converts single-phase alternating current to three-phase alternating current. More specifically, the single-phase AC input power source is directly used as the first phase power source of the three-phase AC power source, and then the above AC input power source is converted into one phase, which is different from the phase of the input power source. An inverter comprising: obtaining a second phase power supply of the above three-phase AC power supply; and obtaining a third phase power supply of the above three-phase AC power supply according to the first and second phase wiring connections.
related to data equipment. Problems to be solved by conventional techniques and inventions.

In single-phase induction motors for coolers, washing machines, or refrigerators that are used with a single-phase AC power source wired in ordinary homes, the stator generally consists of a main winding and an auxiliary winding for starting. , and the rotor often has a squirrel cage structure. Single-phase induction motors are different from three-phase induction motors in commercial wiring power supplies.
Currently, the starting and electrical characteristics are inferior, the required materials are slightly larger, and unlike three-phase induction motors, effective winding cannot be provided around the entire circumference of the stator, resulting in a large size.

In order to self-start a single-phase induction motor, measures such as adding a shaded coil or providing a split-phase capacitor are taken, but each method has the disadvantage of complicating the mechanism.

The present invention solves the above-mentioned drawbacks, improves the starting characteristics, increases the efficiency, and furthermore, increases the size compared to a three-phase induction motor and simplifies the machine. It consists of one phase from a single-phase AC input power supply and another phase obtained from this negative phase using a single-phase conversion circuit.
The purpose is to obtain a three-phase AC power supply, which is obtained by adding one phase according to the wiring, in an appliance of an electric appliance connected to a single-phase wiring in a general household.

Embodiment In order to obtain a three-phase AC output power source from a conventional single-phase AC input power source, three mutually symmetrical three-phase converters 2 were used in parallel as shown in FIG. In the inverter device of the present invention, as shown in FIG.
is directly connected to one phase U and ■ of the three-phase AC output power source 3 without going through the one-phase converter 4, and the input power source 1 is connected to the phase of the input power source 1 through the switched one-phase converter 4. An output with a phase difference of 120° from that of the output power source 3 is obtained, and this is connected to another phase (2) and W of the output power source 3. Furthermore, the above one phase W and the above one phase U are the input power supply phase U-V phase and V-W
By combining the phases, the power supply 3 outputs outputs with 240' different phases.
can be obtained.

In FIG. 1, the output side of a transformer 5 whose input side is connected to the input power source 1 is connected to a rectifier 6.

The DC output of rectifier 6 is connected to transistors 9 and 12 via a smoothing circuit consisting of choke coils 7 and 10 and capacitors 8 and 11.

Transistors 9 and 12 each have their outputs generated under PWM control of the input signal terminal 13 for phase conversion connected to the terminal W of the output power supply 3, and the neutral point of the rectifier circuit is connected to the terminal ■ of the output power supply 3. be done.

Terminals μ and V of input chamber #, 1 are directly connected to terminals U and V of output power supply 3, respectively. In addition, although the center tap method was used to generate the positive and negative DC outputs in this embodiment, the voltage across the secondary side of the transformer 5 was used.
Rectifier f3f in positive and negative directions: Even if the two sets of bridge method are used,
The invention can be fully implemented.

The operation of the circuit of FIG. 1 is illustrated in FIG. In FIG. 4, the single-phase AC input voltage waveform B1 applied between terminals μ and 7 is the switching noise ξ waveform E for phase conversion.
Under the PWM control of 2A and B213, an output voltage waveform E2 whose phase is converted by 120 degrees is generated between terminals V and W as a positive half wave. The output voltage waveform E1, which has the same waveform as the input voltage waveform E1, is combined with the output voltage waveform E2 at the output terminals U, V and W to produce a third output voltage waveform E3, where the output voltage waveforms El, E2 and E3 form a three-phase AC output power supply.

5 and 6, the input voltage waveforms BUA (positive half wave) and BUA' (
negative half-wave) produces output current waveforms IOA and ITJA' across terminals U and 7, respectively, and also across transformer 5
terminals V and W according to their respective input voltage waveforms via
Output voltage waveforms EVA and BVA,'i occur between them. The output current waveforms IVA and ■■8 due to the output voltage waveforms EVA and EV A' together with the output current waveforms IUA and IUA' produce a three-phase alternating current, which in addition to the load windings LX, LY and LZ It will be done.

Among the voltages of the three-phase AC output obtained in this way, the voltage between terminal ■ and terminal W and the voltage between terminal W and terminal U pass through a single-phase converter, compared to the voltage between terminal U and terminal 7. However, this decrease is not enough to cause significant imbalance between the three phases.

However, when extreme precision is required, the load winding between terminals ■ and terminal W can be wound less than the load winding between terminals U and 7 by the amount of voltage drop lost in the single-phase conversion circuit. In addition, the load windings corresponding to the terminals W and U may be wound to a value intermediate between the UV and VW load windings.

Effects of the invention Single-phase AC input power source f: electrification by connecting directly to the load as the first phase, and converting the phase of this first phase using a phase conversion circuit and connecting to the load as the second phase. Now you can understand the complex starting winding or not.

[Brief explanation of the drawing]

FIG. 1 shows the entire circuit of an embodiment of the inverter device of the present invention. FIG. 2 is a schematic diagram showing a circuit system a of an embodiment of a conventional inverter device. FIG. 3 is a schematic diagram showing a circuit system of an embodiment of the inverter device of the present invention. FIG. 4 is a waveform diagram obtained by the circuit of FIG. 1. 5 and 6 are both explanatory diagrams showing the operation of the embodiment of FIG. 1. In the figure: 1: Single-phase input power supply 2: Three-phase converter 3: Three-phase AC output power supply 4 Two-phase converter 5 Two-phase transformer 6: Rectifier 7.8, 10, 11: Smoothing circuit 9.1 Transistor 13: Phase conversion Input signal terminal El: input voltage waveform E2. E3: Output voltage waveform E2A, E2B: Phase conversion switching pulse waveform BUA, EUA': Input voltage waveform EVA, EVA': Output voltage waveform IOA, IUA': Output current waveform IVA, IVA': Output current waveform μ+V a input Terminals U, V, W: Output terminals LX, Ly, LZ: Load winding Patent applicant Toyo Aviation Electronics Co., Ltd. agent Patent attorney Ishi 1) Michio agent Patent attorney Takashi Kuwahara X/Zuhata, 41 Figure

Claims (2)

[Claims] (1) Consists of one phase obtained by phase converting a single-phase AC input power source using a one-phase converter, and one phase obtained by phase converting the above-mentioned single-phase AC input power source, This two-phase 1
An inverter device configured to obtain three-phase power by V-connection. (2) The inverter device according to claim 1, which drives electrical appliances connected to the single-phase AC input power source described in item (1) with the three-phase power source obtained by the above-mentioned connection configuration (2).