JPH0451042U

JPH0451042U -

Info

Publication number: JPH0451042U
Application number: JP9001590U
Authority: JP
Priority date: 1990-08-30
Filing date: 1990-08-30
Publication date: 1992-04-30

Description

[Brief explanation of the drawing]

第１図は本考案の実施例の概要を示すブロツク
図、第２図は本考案の他の実施例の要部を示すブ
ロツク図、第３図は第１図の実施例の動作説明用
信号波形図、第４図は第１図の実施例の要部の具
体的な構成例を示す結線図、第５図は従来のイン
バータ出力異常検出手段の例を示すブロツク図、
第６図は第５図の検出手段の動作説明用信号波形
図である。３……インバータ回路、５……フイルタ回路、
６……切換スイツチ、１２……基準正弦波電圧発
生回路、１３……誤差増幅回路、１４……搬送波
発生回路、１５……ＰＷＭ制御回路、１６……ド
ライブ回路、１７，１７′……直流電圧加算回路
、１８，１８′……比較器、１９……切換スイツ
チ制御回路。 FIG. 1 is a block diagram showing an outline of an embodiment of the present invention, FIG. 2 is a block diagram showing main parts of another embodiment of the present invention, and FIG. 3 is a signal for explaining the operation of the embodiment of FIG. 1. 4 is a wiring diagram showing a specific example of the configuration of the main part of the embodiment shown in FIG. 1, FIG. 5 is a block diagram showing an example of a conventional inverter output abnormality detection means,
FIG. 6 is a signal waveform diagram for explaining the operation of the detection means in FIG. 5. 3... Inverter circuit, 5... Filter circuit,
6... Selector switch, 12... Reference sine wave voltage generation circuit, 13... Error amplification circuit, 14... Carrier wave generation circuit, 15... PWM control circuit, 16... Drive circuit, 17, 17'... DC Voltage addition circuit, 18, 18'... Comparator, 19... Changeover switch control circuit.

Claims

[Claims for Utility Model Registration] (1) A semiconductor switching element control/inverter circuit 3 into which DC power is input, which is controlled to open and close by a drive signal and outputs sinusoidal AC power through a filter circuit 5; and the inverter circuit 3. When the output is normal, the output is supplied to the load, and when the output is abnormal, it is controlled by the switching signal to switch and output the commercial power supply power to the load. a reference sine wave voltage generation circuit 12 that outputs a reference sine wave voltage; an error amplification circuit 13 that outputs an error amplified signal based on the difference between the output feedback voltage of the inverter circuit 3 and the reference sine wave voltage; PW in which the carrier wave signal of is pulse width modulated by the error amplified signal.
A PWM control circuit 15 that outputs an M control signal to control opening and closing of the semiconductor switching elements of the inverter circuit 3.
An uninterruptible AC power supply device comprising: inputting the reference sine wave voltage and adding positive and negative DC voltages of predetermined magnitude to the reference voltage;
a DC voltage adder circuit 17 that outputs two reference signals that are superimposed and have a predetermined magnitude relationship with respect to the error amplified signal, and compares the error amplified signal with the two reference signals to determine the magnitude of the error amplified signal. a comparator 18 that outputs an inverter output abnormality detection signal when exceeds a predetermined range defined by the two reference signals;
and a changeover switch control circuit 19 that outputs a changeover signal to the changeover switch 6 in response to input of the inverter output abnormality detection signal. (2) A semiconductor switching element control/inverter circuit 3 into which DC power is input, which is controlled to open and close by a drive signal and outputs sinusoidal AC power through a filter circuit 5; and when the output of the inverter circuit 3 is normal, the output is a load. a changeover switch 6 that switches and outputs commercial power supply power to the load under the control of a switching signal when the output is abnormal, and a reference sine wave voltage generation circuit that outputs a reference sine wave voltage that is phase-synchronized with the commercial power supply voltage. 12; an error amplification circuit 13 that outputs an error amplification signal based on the difference between the output feedback voltage of the inverter circuit 3 and the reference sine wave voltage; PW modulated by pulse width
A PWM control circuit 15 that outputs an M control signal to control opening and closing of the semiconductor switching elements of the inverter circuit 3.
An uninterruptible AC power supply device comprising: inputting the reference sine wave voltage and adding positive and negative DC voltages of predetermined magnitude to the reference voltage;
a DC voltage adder circuit 17' that outputs two reference signals that are superimposed and have a predetermined magnitude relationship with respect to the output feedback signal of the inverter circuit 3; and an output feedback of the inverter circuit 3 that has the same phase as the reference sine wave voltage. a comparator 18' that compares the signal with the two reference signals and outputs an inverter output abnormality detection signal when the magnitude of the output feedback signal exceeds a predetermined range defined by the two reference signals; An uninterruptible AC power supply apparatus comprising a changeover switch control circuit 19 that outputs a changeover signal to the changeover switch 6 in response to an input of an inverter output abnormality detection signal.