JPS6320114B2

JPS6320114B2 -

Info

Publication number: JPS6320114B2
Application number: JP55071905A
Authority: JP
Inventors: Hiroshi Yokota
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1980-05-27
Filing date: 1980-05-27
Publication date: 1988-04-26
Also published as: JPS56166778A

Description

【発明の詳細な説明】本発明は、短時間で交流電源に対して同期電動
機を揃速及び同期化させる同期電動機の始動制御
装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting control device for a synchronous motor that can uniformly speed and synchronize a synchronous motor with respect to an AC power source in a short period of time.

従来、この種の始動制御装置としてのサイリス
タ始動方式は、順変換器と逆変換器とからなる半
導体電力変換器の点弧角を制御して同期電動機を
加速し、同期速度の90％〜95％で定電流加速から
同期速度を目標とする定速度制御や揃速制御に切
換えるようにしていた。 Conventionally, the thyristor starting method as this kind of starting control device accelerates a synchronous motor by controlling the firing angle of a semiconductor power converter consisting of a forward converter and an inverse converter, and accelerates the synchronous motor to a speed of 90% to 95% of the synchronous speed. %, switching from constant current acceleration to constant speed control or uniform speed control that targets synchronous speed.

しかし、定電流加速した後の同期速度付近で
は、半導体電力変換器の点弧角を微調整する必要
があり、また、同期速度の90％〜95％まで定電流
加速された後、その速度から同期速度までの速度
制御を、本来、ほとんど、同期速度になつた状態
からの回転数合せや位相合せ制御が目的である定
速制御装置や揃速制御装置で行うと、加速信号を
与えてもなかなか加速されず、同期投入までの所
要時間が非常に長くなるなどの欠点があつた。 However, near the synchronous speed after constant current acceleration, it is necessary to finely adjust the firing angle of the semiconductor power converter, and after constant current acceleration to 90% to 95% of the synchronous speed, from that speed If speed control up to synchronous speed is originally performed with a constant speed control device or uniform speed control device whose purpose is to control the rotation speed and phase adjustment from the state where the synchronous speed has been reached, even if an acceleration signal is applied, There were drawbacks such as slow acceleration and a very long time required to synchronize.

本発明は、以上のような従来のものの欠点を除
去するためになされたもので、同期速度付近まで
定電流加速された後、その速度から同期投入まで
を短時間に確実に行うようにして、同期電動機の
始動から交流電源に対する同期を得るまでの時間
を短縮することができる同期電動機の始動制御装
置を提供することを目的とする。 The present invention has been made in order to eliminate the drawbacks of the conventional ones as described above, and after constant current acceleration to near synchronous speed, the process from that speed to synchronization is reliably performed in a short time. An object of the present invention is to provide a starting control device for a synchronous motor that can shorten the time from starting the synchronous motor to obtaining synchronization with an AC power source.

以下、本発明の一実施例を図について説明す
る。第１図は本発明の始動制御装置を示すブロツ
ク図である。図において、１は同期電動機、２は
遮断器、３はACリアクトル、４はインバータ、
５はDCリアクトル、６はコンバータ、７は変圧
器、８は遮断器、９は主変圧器で、これらは前記
の順に接続されている。また、１０は同期電動機
１に直結されて回転計として働く発電機、１１は
同期電動機１に直結されその回転子の位置を検出
してインバータ４の点弧角を制御する制御信号を
発生する分配器、１２は分配器１１の制御信号を
入力してインバータ４の点弧信号を発生する制御
回路、１３−１は発電機１０の信号１０ａを入力
し同期電動機１の同期速度の約５〜10％以下で動
作するリレー即ち速度検出器、１３−２は前記同
期速度の約５〜10％以上、約99％以下で動作する
リレー即ち速度検出器、１３−３は前記同期速度
の約99％以上で動作するリレー即ち速度検出器、
１４は速度検出器１３−２，１３−３の出力信号
により切換えられるスイツチ、１４−１は検出器
１３−１の信号によりコンバータ６の断続周波数
を定める制御回路、１４−２は以下で説明する比
較器１６及び揃速装置１８の信号を入力しコンバ
ータ６の点弧位相角を制御する制御回路、１５−
１，１５−２は電流設定器、１６は電流設定器１
５−１又は１５−２の信号と以下で説明する変流
器１７の信号とを図示の極性でもつて比較をする
比較器、１７はコンバータ６、変圧器７間を流れ
る電流の変流器、１８は揃速装置、１９は制御回
路１４−１，１４−２の信号を入力しコンバータ
６の点弧パルスを発生するゲート・パルス発生
器、１９−１は遮断器８、変圧器９間の電圧を検
出して得た出力電圧を揃速装置１８に供給する計
器用変圧器、１９−２は同期電動機１、遮断器２
間の電圧を検出して得た出力電圧を揃速装置１８
に供給する計器用変圧器、２０は発電機遮断器、
２１は同期電動機１に一端を接続し他端を発電機
遮断器２０を介して変圧器９に接続した相反転断
路器で、同期電動機１に直結された原動機（図示
せず）が可逆式の場合、この同期電動機１の発電
機運転時と電動機運転時に相順を切換えるための
ものである。 Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a starting control device of the present invention. In the figure, 1 is a synchronous motor, 2 is a circuit breaker, 3 is an AC reactor, 4 is an inverter,
5 is a DC reactor, 6 is a converter, 7 is a transformer, 8 is a circuit breaker, and 9 is a main transformer, which are connected in the above order. Further, 10 is a generator that is directly connected to the synchronous motor 1 and serves as a tachometer, and 11 is a generator that is directly connected to the synchronous motor 1 and that detects the position of the rotor and generates a control signal that controls the firing angle of the inverter 4. 12 is a control circuit which inputs the control signal of the distributor 11 and generates the ignition signal of the inverter 4; 13-1 inputs the signal 10a of the generator 10 and controls the synchronous speed of the synchronous motor 1 by approximately 5 to 10 13-2 is a relay or speed detector that operates at about 5 to 10% or more of the synchronous speed and about 99% or less, 13-3 is a relay or speed detector that operates at about 99% of the synchronous speed. Relays or speed detectors that operate above
14 is a switch that is switched by the output signals of the speed detectors 13-2 and 13-3, 14-1 is a control circuit that determines the intermittent frequency of the converter 6 based on the signal of the detector 13-1, and 14-2 is explained below. a control circuit that inputs signals from the comparator 16 and the speed equalizer 18 and controls the firing phase angle of the converter 6; 15-;
1, 15-2 is the current setting device, 16 is the current setting device 1
A comparator that compares the signal of 5-1 or 15-2 with the signal of a current transformer 17, which will be explained below, with the polarity shown; 17 is a current transformer for the current flowing between the converter 6 and the transformer 7; 18 is a speed equalizer, 19 is a gate pulse generator that inputs signals from control circuits 14-1 and 14-2 and generates firing pulses for converter 6, and 19-1 is a gate between circuit breaker 8 and transformer 9. An instrument transformer that detects the voltage and supplies the output voltage obtained to the speed equalizing device 18, 19-2 is a synchronous motor 1, a circuit breaker 2
The output voltage obtained by detecting the voltage between
20 is a generator circuit breaker,
Reference numeral 21 denotes a phase reversing disconnector whose one end is connected to the synchronous motor 1 and the other end is connected to the transformer 9 via the generator circuit breaker 20. In this case, this is for switching the phase order when the synchronous motor 1 is operating as a generator and when the motor is operating.

次に第２図に示すグラフを参照して動作を説明
する。第２図において、横軸は時間ｔ、縦軸は同
期電動機１の速度Ｖ（％）及び電流Ｉを示す。遮
断器２及び８を投入すると、コンバータ６は変圧
器７から供給された交流電力を直流電力に変換
し、この直流電力をインバータ４により交流電力
に変換し、この交流電力により同期電動機１が断
続された電流I₀により起動される。 Next, the operation will be explained with reference to the graph shown in FIG. In FIG. 2, the horizontal axis shows time t, and the vertical axis shows the speed V (%) and current I of the synchronous motor 1. When the circuit breakers 2 and 8 are turned on, the converter 6 converts the AC power supplied from the transformer 7 into DC power, and the inverter 4 converts this DC power into AC power. It is activated by the current I ₀ generated.

しかし、最初は同期電動機１の回転速度が低い
ので、その逆起電力が小さく、インバータ４のサ
イリスタの負荷転流が困難である。 However, since the rotational speed of the synchronous motor 1 is initially low, its back electromotive force is small and load commutation of the thyristor of the inverter 4 is difficult.

従つて、インバータ４は位相制御により電流を
断続させ、転流を確実に行うように制御してい
る。その後、回転速度が５〜10％以上に達する
と、負荷転流に移行し、一定の電流I₁で加速が行
なわれる。 Therefore, the inverter 4 is controlled to intermittent the current by phase control to ensure commutation. After that, when the rotational speed reaches 5 to 10% or more, load commutation is started and acceleration is performed with a constant current _I1 .

以上の制御を第１ステツプと呼ぶ。即ち、第１
ステツプでは、電流設定器１５−１より出力され
る設定値、即ち同期電動機１を同期速度付近まで
加速させる電流I₁と変流器１７の信号とを比較器
１６により比較し、比較結果が制御回路１４−２
に入力される。 The above control is called the first step. That is, the first
In step, the comparator 16 compares the set value output from the current setter 15-1, that is, the current I1 that accelerates the synchronous motor ₁ to around the synchronous speed, with the signal from the current transformer 17, and the comparison result is used to control the Circuit 14-2
is input.

これによつて得た制御回路１４−２の制御信号
は、ゲート・パルス発生器１９に入力され、点弧
パルスとなつてコンバータ６に供給される。この
ようにして同期電動機１の回転速度が同期速度の
99％に達すると、第２ステツプに制御に入る。 The control signal of the control circuit 14-2 thus obtained is input to the gate pulse generator 19, and is supplied to the converter 6 as an ignition pulse. In this way, the rotational speed of the synchronous motor 1 is changed to the synchronous speed.
When it reaches 99%, it enters the second step of control.

第２ステツプでは、発電機１０の信号１０ａに
より検出器１３−３が動作をし、スイツチ１４を
図示と逆の位置に設定する。このため、電流設定
器１５−２の設定値、即ち同期速度における負荷
トルクに見合つたトルクを得る電流I₂（第３図参
照）が比較器１６に入力され、以下第１ステツプ
の説明と同じようにしてコンバータ６を制御す
る。 In the second step, the detector 13-3 is activated by the signal 10a from the generator 10, and the switch 14 is set to the opposite position as shown. Therefore, the setting value of the current setter 15-2, that is, the current I ₂ (see Fig. 3) that obtains a torque commensurate with the load torque at the synchronous speed, is input to the comparator 16, and the following is the same as the explanation of the first step. The converter 6 is controlled in this way.

同期電動機１を含む回転系の慣性は大きいが、
第２ステツプでは加速トルクがないので、同期電
動機１は同期速度付近で安定した状態のままであ
る。 Although the inertia of the rotating system including the synchronous motor 1 is large,
Since there is no accelerating torque in the second step, the synchronous motor 1 remains stable near the synchronous speed.

そして、電流設定器１５−２によつて設定され
た電流I₂とこの変流器１７の信号とが一致する
と、比較器１６の出力が零となる。次に第３ステ
ツプとして揃速装置１８を生かし、計器用変圧器
１９−１，１９−２間の位相差を検出し位相を合
せるための揃速信号を制御回路１４−２に供給す
る。 When the current I ₂ set by the current setter 15-2 and the signal from the current transformer 17 match, the output of the comparator 16 becomes zero. Next, as a third step, the speed equalizing device 18 is utilized to detect the phase difference between the instrument transformers 19-1 and 19-2, and supply a speed equalizing signal for matching the phases to the control circuit 14-2.

これにより、同期電動機１は、周波数又は位相
差によつて微速制御され、同期した時点で揃速装
置１８により発電機遮断器２０を投入して起動を
完了する。 Thereby, the synchronous motor 1 is controlled at a slow speed by the frequency or phase difference, and when synchronized, the generator circuit breaker 20 is closed by the speed equalizing device 18 to complete the startup.

以上のように、この発明によれば、始動から同
期速度付近までの定電流加速域では、定電流加速
させる電流を設定値とする第１の電流設定器を選
択し、同期速度付近の回転速度になつた後の定速
制御域では、同期電動機の同期速度における負荷
トルクに見合つた電動機トルクに対応する該同期
電動機の電流を設定値とする第２の電流設定器を
選択し、選択した各電流設定器の設定値に基づい
て同期電動機を始動制御するように構成したの
で、定電流加速制御後の定速制御域では加速トル
クがなく、同期電動機は同期速度付近で安定状態
を保持する。この結果、すでに同期のチヤンスが
できていることにより、わずかの揃速制御にて同
期投入が確実に行なわれるもので、定速制御域が
短かくなり、同起投入までの始動時間を短縮する
ことができる効果がある。 As described above, according to the present invention, in the constant current acceleration range from starting to around the synchronous speed, the first current setter whose setting value is the current for constant current acceleration is selected, and the rotation speed around the synchronous speed is In the constant speed control region after the synchronous speed is reached, a second current setter is selected whose setting value is the current of the synchronous motor corresponding to the motor torque commensurate with the load torque at the synchronous speed of the synchronous motor, and each of the selected Since the synchronous motor is configured to perform starting control based on the setting value of the current setting device, there is no acceleration torque in the constant speed control region after constant current acceleration control, and the synchronous motor maintains a stable state near the synchronous speed. As a result, since there is already a chance of synchronization, synchronization can be reliably performed with a small amount of uniform speed control, which shortens the constant speed control range and shortens the starting time until simultaneous startup. There is an effect that can be done.

[Brief explanation of the drawing]

第１図はこの発明の一実施例による同期電動機
の始動制御装置の一実施例を示すブロツク図、第
２図はこの発明の動作を説明するグラフ、第３図
は同期電動機の特性を示すグラフである。１は同期電動機、４はインバータ、６はコンバ
ータ、１０は発電機、１２，１４−１，１４−２
は制御回路、１３−１，１３−２，１３−３は検
出器、１５−１，１５−２は設定器、１６は比較
器。 Fig. 1 is a block diagram showing an embodiment of a starting control device for a synchronous motor according to an embodiment of the present invention, Fig. 2 is a graph explaining the operation of the invention, and Fig. 3 is a graph showing characteristics of the synchronous motor. It is. 1 is a synchronous motor, 4 is an inverter, 6 is a converter, 10 is a generator, 12, 14-1, 14-2
13-1, 13-2, 13-3 are detectors, 15-1, 15-2 are setters, and 16 is a comparator.

Claims

[Claims]

1 A synchronous motor is connected to an AC power source through a semiconductor power converter consisting of a forward converter and an inverse converter,
The rotation speed of the synchronous motor is controlled by controlling the current supplied to the synchronous motor and its frequency by the control of the semiconductor power converter, and the frequency of the voltage applied to the armature of the synchronous motor and the AC power supply are controlled. In a starting control device for a synchronous motor that controls power so that the frequency of the voltage of the synchronous motor is equal to the frequency of the voltage of a second current setter whose set value is a current of the synchronous motor corresponding to a motor torque commensurate with the load torque; and a second current setter that detects the rotational speed of the synchronous motor and sets the first current from the start to around the synchronous speed. a switch that selects a setting value of the setting device, and selects a setting value of the second current setting device from the rotation speed near the synchronous speed; and an input current value of the semiconductor power converter selected by the switch a comparator that compares the setting value of the current setting device, a control circuit that controls the firing angle of the semiconductor power converter so that the output signal of the comparator becomes small; A synchronous motor characterized by comprising a speed equalizing device that supplies a speed equalizing signal to the control circuit after acceleration to control the synchronous motor at a fine speed and connects the synchronous motor to the alternating current power supply at the time of synchronization. Starting control device.