JPH02114341U

JPH02114341U -

Info

Publication number: JPH02114341U
Application number: JP2399189U
Authority: JP
Priority date: 1989-03-02
Filing date: 1989-03-02
Publication date: 1990-09-13

Description

【図面の簡単な説明】[Brief explanation of the drawing]

第１図〜第３図は、この考案の一実施例を示す
図であり、第１図はインバータの保護回路を示す
図、第２図は回生時の電流の流れを示す図、第３
図は回生時の直流母線と出力の電流を比較した図
、第４図、第５図は従来のインバータの保護回路
を示す図である。図において、１は商用電源、２は順変器、３は
コンデンサ、４はスイツチング素子、５はモータ
、６はマイクロプロセツサ、７はしや断回路、８
は正転指令器、１０は逆転指令器、９，１１はプ
ルアツプ抵抗、１２は周波数設定ボリユーム、１
３は加速時間設定器、１４は減速時間設定器、１
５は電流検出器、１６は過電流レベル設定、１７
，１８は比較器、１９は選択回路、２０はラツチ
、２１は増幅器、２２は電流検出器、２３は加算
器と整流回路、２４は減速時間設定器である。な
お、図中、同一符号は同一、又は相当部分を示す
。 Figures 1 to 3 are diagrams showing an embodiment of this invention. Figure 1 is a diagram showing an inverter protection circuit, Figure 2 is a diagram showing the flow of current during regeneration, and Figure 3 is a diagram showing an inverter protection circuit.
The figure is a diagram comparing the current of the DC bus and the output during regeneration, and FIGS. 4 and 5 are diagrams showing a conventional inverter protection circuit. In the figure, 1 is a commercial power supply, 2 is a forward transformer, 3 is a capacitor, 4 is a switching element, 5 is a motor, 6 is a microprocessor, 7 is a disconnection circuit, and 8 is a
is a forward rotation command, 10 is a reverse rotation command, 9 and 11 are pull-up resistors, 12 is a frequency setting volume, 1
3 is an acceleration time setter, 14 is a deceleration time setter, 1
5 is a current detector, 16 is an overcurrent level setting, 17
, 18 is a comparator, 19 is a selection circuit, 20 is a latch, 21 is an amplifier, 22 is a current detector, 23 is an adder and rectifier circuit, and 24 is a deceleration time setter. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims

【実用新案登録請求の範囲】[Scope of utility model registration request]

直流を可変周波数、可変電圧の交流に変換する
インーバータ装置において、固定の過電流レベル
と、減速時間を設定するボリユームの値により変
化する過電流レベルの２つを備えてなり、加速定
速時と、減速時にて上記２つの過電流レベルを選
択するようにし、減速時間が短い場合は、過電流
レベルを下げるよう構成したことを特徴とするイ
ンバータの保護回路。 An inverter device that converts direct current into alternating current with variable frequency and variable voltage has two overcurrent levels: a fixed overcurrent level and an overcurrent level that changes depending on the volume value that sets the deceleration time. An inverter protection circuit characterized in that the above two overcurrent levels are selected during deceleration, and the overcurrent level is lowered when the deceleration time is short.