JP2017085805A

JP2017085805A - Air conditioner

Info

Publication number: JP2017085805A
Application number: JP2015212675A
Authority: JP
Inventors: 武礼吉田; Takeyuki Yoshida
Original assignee: Fujitsu General Ltd
Current assignee: Fujitsu General Ltd
Priority date: 2015-10-29
Filing date: 2015-10-29
Publication date: 2017-05-18
Anticipated expiration: 2035-10-29
Also published as: JP6500743B2

Abstract

PROBLEM TO BE SOLVED: To surely prevent overvoltage from being generated by iron resonance in an air conditioner and to temporarily operate a power source for control until emergency processing such as normally stopping equipment is completed if phase interruption occurs.SOLUTION: The air conditioner comprises filter means 6 and an outdoor unit control part 24. If phase interruption is detected by a phase interruption detection part 20 and overvoltage is detected by an overvoltage detection part 21, the filter means outputs an abnormal state signal notifying a user about occurrence of iron resonance caused by a power supply transformer 23, connects a resistor 53 to a (c) contact of a relay 51 in place of a capacitor 52, connects a resistor 43 to a (c) contact of a relay 41 in place of a capacitor 42 and connects a resistor 33 to a (c) contact of a relay 31 in place of a capacitor 32. The outdoor unit control part is operated by a DC voltage that is generated using a voltage of the power supply transformer 23, and executes processing adaptive to the occurrence of iron resonance in the case where the abnormal state signal is inputted.SELECTED DRAWING: Figure 1

Description

本発明は、三相交流電源で動作する空気調和機に係わり、より詳細には、三相交流電源に接続された電源トランスと各相間に接続されたコンデンサにより欠相時に発生する鉄共振を防止する構成に関する。 The present invention relates to an air conditioner that operates with a three-phase AC power source, and more specifically, prevents an iron resonance that occurs during a phase loss by a power transformer connected to the three-phase AC power source and a capacitor connected between the phases. Concerning the configuration to

従来、三相電源を使用してそれぞれの相間にノイズ除去用のコンデンサが接続された機器において、二相間に電源トランスを接続し、このトランスから制御用のＤＣ電源を生成する構成がある。この時、トランスに接続されている相の何れか１つが欠相となった場合、コンデンサとトランスが直列となって鉄共振による過電圧が発生する。このため、トランスの焼損や部品の破壊が発生する場合があった。 2. Description of the Related Art Conventionally, there is a configuration in which a power transformer is connected between two phases in a device in which a noise removing capacitor is connected between each phase using a three-phase power source, and a control DC power source is generated from the transformer. At this time, if any one of the phases connected to the transformer is lost, an overvoltage due to iron resonance occurs with the capacitor and the transformer in series. For this reason, transformer burnout and component destruction may occur.

鉄共振による過電圧の対策のためには発生が予想される過電圧以上の耐圧を有する部品を使用しなければならずコスト上昇となる。もしくは、鉄共振が発生しないようにトランスの仕様と、このトランスの負荷を実験的に決定する必要があるが、負荷の変動や電源電圧の変動があるために鉄共振の発生を完全に防止することはできない。 In order to take measures against overvoltage due to iron resonance, it is necessary to use a component having a withstand voltage higher than the overvoltage expected to be generated, resulting in an increase in cost. Alternatively, it is necessary to experimentally determine the transformer specifications and the load of this transformer so that iron resonance does not occur. However, because of load fluctuations and power supply voltage fluctuations, the occurrence of iron resonance is completely prevented. It is not possible.

このような三相交流電源を用いた回路で発生する鉄共振を防止するものとして、図４に示す特許文献１の構成が開示されている。
図４はＡ相、Ｂ相およびＣ相の受電ケーブル１３０ａ〜１３０ｃからなる三相交流電路１３０に負荷開閉器１００を設置した構成を示している。また、受電ケーブル１３０ａ〜１３０ｃにコンデンサ１４０ａ〜１４０ｃの一端がそれぞれ接続され、コンデンサ１４０ａ〜１４０ｃの他端がアースに接続されている。
一方、負荷開閉器１００内には計器用変圧器１２０が備えられており、この計器用変圧器１２０の一次巻線にコンデンサ１５０が並列に接続されている。 As a means for preventing iron resonance that occurs in a circuit using such a three-phase AC power supply, the configuration of Patent Document 1 shown in FIG. 4 is disclosed.
FIG. 4 shows a configuration in which the load switch 100 is installed in the three-phase AC circuit 130 including the A-phase, B-phase, and C-phase power receiving cables 130a to 130c. Further, one ends of capacitors 140a to 140c are connected to power receiving cables 130a to 130c, respectively, and the other ends of capacitors 140a to 140c are connected to the ground.
On the other hand, an instrument transformer 120 is provided in the load switch 100, and a capacitor 150 is connected in parallel to the primary winding of the instrument transformer 120.

例えばＡ相が欠相した場合、Ｂ相の電圧とＣ相の電圧が印加される回路、つまり、受電ケーブル１３０ｂ、コンデンサ１４０ｂ、コンデンサ１４０ａ、計器用変圧器１２０、受電ケーブル１３０ｃからなる直列共振回路が形成されるが、図４に示すように計器用変圧器１２０の一次巻線にコンデンサ１５０を並列に接続した回路にすることにより計器用変圧器１２０の両端に印加される交流電圧をコンデンサ１５０でバイパスするため、鉄共振の発生を防止する構成になっている。 For example, when the A phase is lost, a circuit to which a B phase voltage and a C phase voltage are applied, that is, a series resonant circuit including a power receiving cable 130b, a capacitor 140b, a capacitor 140a, an instrument transformer 120, and a power receiving cable 130c. As shown in FIG. 4, an AC voltage applied to both ends of the instrument transformer 120 is converted to the capacitor 150 by forming a circuit in which the capacitor 150 is connected in parallel to the primary winding of the instrument transformer 120 as shown in FIG. 4. Therefore, the iron resonance is prevented from occurring.

しかしながら、鉄共振は電源周波数の１／３の周波数で発振するため、この低い共振周波数での発振を防止するために容量の大きなコンデンサが必要であり、コストが上昇する問題があった。また、この容量の大きなコンデンサに常に交流電流が流れ続けるため消費電流が増加する問題もあった。
一方、図示しない空気調和機にはインバータや、これで駆動される圧縮機、各受電ケーブル間に接続されたノイズフィルタ用のコンデンサ、三相交流電源の電圧を変圧する電源トランス、この電源トランスの出力電圧を整流した直流電源で動作する制御部が備えられている。鉄共振が発生しない欠相であれば、このノイズフィルタ用のコンデンサを介して欠相した電圧以外の他の相の電圧が電源トランスに供給されるため、制御部は継続動作が可能である。
しかしながら、欠相により発生した鉄共振を防止するために、空気調和機の制御部がノイズフィルタ用のコンデンサと交流電源が接続される受電ケーブルの間の接続を切断した場合、制御部を動作させる電圧も同時に供給されなくなるため、制御部がインバータや圧縮機の停止処理を正常に行なうことができず、場合によってはスイッチング素子などの部品を破壊するおそれがあった。 However, since iron resonance oscillates at a frequency that is 1/3 of the power supply frequency, a capacitor having a large capacity is necessary to prevent oscillation at this low resonance frequency, which raises the problem of an increase in cost. There is also a problem that the consumption current increases because an alternating current always flows through the capacitor having a large capacity.
On the other hand, the air conditioner (not shown) includes an inverter, a compressor driven by the inverter, a noise filter capacitor connected between each power receiving cable, a power transformer that transforms the voltage of the three-phase AC power source, and the power transformer. A control unit that operates with a DC power source that rectifies the output voltage is provided. If the phase loss is such that no iron resonance occurs, a voltage of a phase other than the phase loss voltage is supplied to the power transformer via the noise filter capacitor, so that the control unit can continue operation.
However, in order to prevent the iron resonance caused by the open phase, when the control unit of the air conditioner disconnects the connection between the noise filter capacitor and the power receiving cable to which the AC power supply is connected, the control unit is operated. Since the voltage is not supplied at the same time, the control unit cannot normally stop the inverter and the compressor, and there is a possibility that components such as the switching element may be destroyed in some cases.

特開２００８−５３３３４号公報（第４−５頁、図１）JP 2008-53334 A (page 4-5, FIG. 1)

空気調和機において、確実に鉄共振による過電圧発生を防止し、かつ、欠相が発生した場合に機器の正常停止を行なうなどの緊急処理が完了するまで一時的に制御用電源を動作させることを目的とする。 In an air conditioner, it is necessary to temporarily prevent the occurrence of overvoltage due to iron resonance and to temporarily operate the control power supply until emergency processing such as normal shutdown of the equipment is completed when a phase loss occurs. With the goal.

本発明は上述の課題を解決するため、本発明の請求項１に記載の発明は、Ａ相とＢ相とＣ相とからなる三相交流電源に接続され、同三相交流電源を直流電源に変換する第１整流回路と、前記第１整流回路の出力が入力されるインバータと、同インバータで駆動される圧縮機のモータとを備えた室外機と、同室外機に通信接続された室内機とを備え、
前記室外機は、前記Ａ相と前記Ｂ相と前記Ｃ相の電圧がそれぞれ印加される第１電源ラインと第２電源ラインと第３電源ラインと、前記Ａ相と前記Ｂ相と前記Ｃ相のいずれかの印加電圧の欠相を検出して欠相検出信号を出力する欠相検出部と、前記三相交流電源の電圧を変圧して出力する電源トランスと、同電源トランスに印加される電圧の過電圧を検出して過電圧検出信号を出力する過電圧検出部と、前記電源トランスの出力電圧を直流電圧に変換して出力する第２整流回路とを備えた空気調和機であって、
前記室外機は、
それぞれの共通接点が相互に接続され、それぞれの第１接点又はそれぞれの第２接点が切り換えられて前記共通接点に接続される第１リレ−と第２リレーと第３リレーと、第１抵抗と第２抵抗と第３抵抗と、第１コンデンサと第２コンデンサと第３コンデンサを備え、前記欠相検出信号と前記過電圧検出信号が入力されるフィルタ手段と、
前記第２整流回路が出力する直流電圧によって動作し、前記インバータを介して前記圧縮機のモータを駆動する制御手段とを備え、
前記フィルタ手段は、
前記第１電源ラインに前記第１コンデンサと前記第１抵抗のそれぞれの一端が接続され、前記第１抵抗の他端が前記第１リレーの第１接点に接続され、前記第１コンデンサの他端が前記第１リレーの第２接点に接続され、
前記第２電源ラインに前記第２コンデンサと前記第２抵抗のそれぞれの一端が接続され、前記第２抵抗の他端が前記第２リレーの第１接点に接続され、前記第２コンデンサの他端が前記第２リレーの第２接点に接続され、
前記第３電源ラインに前記第３コンデンサと前記第３抵抗のそれぞれの一端が接続され、前記第３抵抗の他端が前記第３リレーの第１接点に接続され、前記第３コンデンサの他端が前記第３リレーの第２接点に接続されており、
前記フィルタ手段は、
前記欠相検出部が欠相を検出し、かつ、前記過電圧検出部が過電圧を検出した時、前記電源トランスによる鉄共振の発生を通知する異常状態信号を前記制御手段に出力すると共に、前記第１リレーの共通接点に前記第１抵抗を、前記第２リレーの共通接点に前記第２抵抗を、前記第３リレーの共通接点に前記第３抵抗をそれぞれ接続して、前記鉄共振を停止させ、
前記制御手段は、
前記異常状態信号が入力された時、前記第１抵抗と前記第２抵抗と前記第３抵抗のいずれかを経由して前記電源トランスで変圧された前記三相交流電源の電圧を用いて動作すると共に、前記インバータによる前記圧縮機のモータ駆動を停止させる、もしくは前記圧縮機のモータの回転数を低下させる処理を実行する。 In order to solve the above-mentioned problems, the present invention according to claim 1 of the present invention is connected to a three-phase AC power source comprising an A phase, a B phase and a C phase, and the three-phase AC power source is connected to a DC power source. An outdoor unit comprising a first rectifier circuit for converting to an inverter, an inverter to which the output of the first rectifier circuit is input, a compressor motor driven by the inverter, and an indoor unit connected to the outdoor unit by communication Equipped with a machine,
The outdoor unit includes a first power line, a second power line, a third power line, an A phase, a B phase, and a C phase to which the voltages of the A phase, the B phase, and the C phase are applied, respectively. The phase loss detection unit that detects the phase loss of any of the applied voltages and outputs a phase loss detection signal, the power transformer that transforms and outputs the voltage of the three-phase AC power supply, and the power transformer An air conditioner comprising: an overvoltage detection unit that detects an overvoltage of the voltage and outputs an overvoltage detection signal; and a second rectifier circuit that converts the output voltage of the power transformer into a DC voltage and outputs the DC voltage.
The outdoor unit is
The common contacts are connected to each other, and the first relay, the second relay, the third relay, the first resistor, and the first contact or the second contact are switched to be connected to the common contact. Filter means comprising a second resistor, a third resistor, a first capacitor, a second capacitor, and a third capacitor, to which the phase loss detection signal and the overvoltage detection signal are input;
Control means for operating by a DC voltage output from the second rectifier circuit and driving a motor of the compressor via the inverter;
The filter means includes
One end of each of the first capacitor and the first resistor is connected to the first power supply line, the other end of the first resistor is connected to a first contact of the first relay, and the other end of the first capacitor. Is connected to the second contact of the first relay,
One end of each of the second capacitor and the second resistor is connected to the second power supply line, the other end of the second resistor is connected to a first contact of the second relay, and the other end of the second capacitor. Is connected to the second contact of the second relay,
One end of each of the third capacitor and the third resistor is connected to the third power supply line, the other end of the third resistor is connected to a first contact of the third relay, and the other end of the third capacitor Is connected to the second contact of the third relay,
The filter means includes
When the phase loss detection unit detects a phase loss and the overvoltage detection unit detects an overvoltage, an abnormal state signal notifying the occurrence of iron resonance by the power transformer is output to the control means, and The first resistor is connected to the common contact of one relay, the second resistor is connected to the common contact of the second relay, and the third resistor is connected to the common contact of the third relay to stop the iron resonance. ,
The control means includes
When the abnormal state signal is input, it operates using the voltage of the three-phase AC power source transformed by the power transformer via any one of the first resistor, the second resistor, and the third resistor. At the same time, a process of stopping the motor drive of the compressor by the inverter or reducing the rotational speed of the motor of the compressor is executed.

以上の手段を用いることにより、本発明による空気調和機によれば、請求項１に係わる発明は、空気調和機において確実に鉄共振による過電圧発生を防止し、かつ、欠相が発生した場合に緊急処理が完了するまで一時的に制御用電源を動作させることができる。 By using the above means, according to the air conditioner according to the present invention, the invention according to claim 1 reliably prevents overvoltage generation due to iron resonance in the air conditioner, and when an open phase occurs. The control power supply can be temporarily operated until the emergency process is completed.

本発明による空気調和機の実施例を示すブロック図である。It is a block diagram which shows the Example of the air conditioner by this invention. 各電源ラインに印加される電圧が欠相となった時を示す要部ブロック図である。It is a principal part block diagram which shows a time when the voltage applied to each power supply line becomes a phase loss. 本発明による空気調和機の動作を説明する説明図である。It is explanatory drawing explaining operation | movement of the air conditioner by this invention. 従来の鉄共振防止の構成を示すブロック図である。It is a block diagram which shows the structure of the conventional iron resonance prevention.

以下、本発明の実施の形態を、添付図面に基づいた実施例として詳細に説明する。なお、本発明に関係のない冷媒回路などは図示と説明を省略する。 DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail as examples based on the attached drawings. Note that illustration and description of refrigerant circuits and the like not related to the present invention are omitted.

図１は本発明による空気調和機１の実施例を示すブロック図である。この空気調和機１は室内機２と室外機３が通信接続されている。
室外機３は、図示しない三相交流電源のＡ相電圧が印加される入力端１４と、Ｂ相電圧が印加される入力端１５と、Ｃ相電圧が印加される入力端１６と、入力端１４に接続された電源ライン１１（第１電源ライン）と、入力端１５に接続された電源ライン１２（第２電源ライン）と、入力端１５に接続された電源ライン１３（第３電源ライン）と、これらの電源ラインが入力に接続された直流電源部１７（第１整流回路）と、直流電源部１７の出力が入力に接続されるインバータ１８と、このインバータ１８の出力に接続された圧縮機のモータ１９を備えている。 FIG. 1 is a block diagram showing an embodiment of an air conditioner 1 according to the present invention. In this air conditioner 1, an indoor unit 2 and an outdoor unit 3 are communicatively connected.
The outdoor unit 3 includes an input end 14 to which a phase A voltage of a three-phase AC power source (not shown) is applied, an input end 15 to which a phase B voltage is applied, an input end 16 to which a phase C voltage is applied, and an input end. 14, a power line 11 (first power line) connected to 14, a power line 12 (second power line) connected to the input terminal 15, and a power line 13 (third power line) connected to the input terminal 15. A DC power supply unit 17 (first rectifier circuit) in which these power supply lines are connected to the input, an inverter 18 in which the output of the DC power supply unit 17 is connected to the input, and a compression connected to the output of the inverter 18 A machine motor 19 is provided.

また、室外機３は、三相交流電源のいずれかの相電圧の欠相を検出して欠相検出信号を出力する欠相検出部２０と、電源ライン１１と電源ライン１３の間に一次側の巻線が接続された電源トランス２２と、この電源トランス２２の両端電圧の過電圧を検出して過電圧信号を出力する過電圧検出部２１と、電源トランス２２の二次側に接続されて直流電圧を出力する制御用電源部２３（第２整流回路）と、ここから出力された直流電圧で動作し、欠相検出信号と過電圧検出信号が入力され、インバータ１８に駆動信号を出力し、室内機２と通信を行なう室外機制御部２４（制御手段）と、電源ライン１１〜１３に接続されるフィルタ部６（フィルタ手段）を備えている。なお、フィルタ部６と過電圧検出部２１と欠相検出部２０も制御用電源部２３から出力された直流電圧で動作する。 The outdoor unit 3 detects the phase loss of any phase voltage of the three-phase AC power supply and outputs a phase loss detection signal, and the primary side between the power supply line 11 and the power supply line 13. Is connected to the secondary side of the power transformer 22 by detecting an overvoltage at both ends of the power transformer 22 and outputting an overvoltage signal. The control power supply unit 23 (second rectifier circuit) for output and the DC voltage output therefrom operate, the phase loss detection signal and the overvoltage detection signal are input, the drive signal is output to the inverter 18, and the indoor unit 2 The outdoor unit control unit 24 (control unit) that communicates with the power supply line 11 and the filter unit 6 (filter unit) connected to the power supply lines 11 to 13 are provided. The filter unit 6, the overvoltage detection unit 21, and the phase loss detection unit 20 also operate with the DC voltage output from the control power supply unit 23.

フィルタ部６は、リレー５１（第１リレー）とリレー４１（第２リレー）とリレー３１（第３リレー）と、これらのリレーを同時に駆動する駆動回路９と、アンド回路７と、フリップフロップ８と、抵抗５３（第１抵抗）と抵抗４３（第２抵抗）と抵抗３３（第３抵抗）と、コンデンサ５２（第１コンデンサ）とコンデンサ４２（第２コンデンサ）とコンデンサ３２（第３コンデンサ）を備えている。
なお、各リレーにはａ接点（第１接点）とｂ接点（第２接点）とｃ接点（共通接点）の３つの接点が備えられており、ａ接点かｂ接点かのいずれか一方が切り換えられてｃ接点に接続される。 The filter unit 6 includes a relay 51 (first relay), a relay 41 (second relay), a relay 31 (third relay), a drive circuit 9 that drives these relays simultaneously, an AND circuit 7, and a flip-flop 8. A resistor 53 (first resistor), a resistor 43 (second resistor), a resistor 33 (third resistor), a capacitor 52 (first capacitor), a capacitor 42 (second capacitor), and a capacitor 32 (third capacitor). It has.
Each relay has three contacts, a contact (first contact), b contact (second contact), and c contact (common contact), and either the a contact or the b contact is switched. And connected to the c contact.

また、フィルタ部６は、電源ライン１１に抵抗５３とコンデンサ５２のそれぞれの一端が接続され、抵抗５３の他端がリレー５１のｂ接点に接続され、コンデンサ５２の他端がリレー５１のａ接点に接続され、電源ライン１２に抵抗４３とコンデンサ４２のそれぞれの一端が接続され、抵抗４３の他端がリレー４１のｂ接点に接続され、コンデンサ４２の他端がリレー４１のａ接点に接続され、電源ライン１３に抵抗３３とコンデンサ３２のそれぞれの一端が接続され、抵抗３３の他端がリレー３１のｂ接点に接続され、コンデンサ３２の他端がリレー３１のａ接点に接続されている。そして、各リレーのｃ接点はそれぞれ相互に接続されている。通常の空調運転時は各リレーのｃ接点がそれぞれのリレーのａ接点に接続されるため、電源ライン１１〜１３のそれぞれの線間に各コンデンサが接続されることになり、この各コンデンサで電源ライン１１〜１３のそれぞれの線間に発生するノイズを低減させている。 Further, the filter unit 6 has one end of each of the resistor 53 and the capacitor 52 connected to the power line 11, the other end of the resistor 53 is connected to the b contact of the relay 51, and the other end of the capacitor 52 is the a contact of the relay 51. One end of each of the resistor 43 and the capacitor 42 is connected to the power line 12, the other end of the resistor 43 is connected to the b contact of the relay 41, and the other end of the capacitor 42 is connected to the a contact of the relay 41. One end of each of the resistor 33 and the capacitor 32 is connected to the power line 13, the other end of the resistor 33 is connected to the b contact of the relay 31, and the other end of the capacitor 32 is connected to the a contact of the relay 31. The c contacts of each relay are connected to each other. During normal air-conditioning operation, the c-contact of each relay is connected to the a-contact of each relay, so that each capacitor is connected between each of the power supply lines 11 to 13, and the power is supplied by each capacitor. Noise generated between the lines 11 to 13 is reduced.

アンド回路７の入力端子には欠相検出部２０と過電圧検出部２１の出力が接続されており、アンド回路７の出力端子はフリップフロップ８のセット端子に接続されている。一方、フリップフロップ８のリセット端子には室外機制御部２４が出力するリセット信号を伝達する信号線が接続されており、フリップフロップ８の出力端子は駆動回路９と室外機制御部２４に接続されている。フリップフロップ８は、欠相検出信号と過電圧検出信号が共に出力された時にセットされ、この状態を示す異常状態信号を出力する。一方、室外機制御部２４が出力するリセット信号によりこの状態がリセットされる。 The output of the phase loss detector 20 and the overvoltage detector 21 is connected to the input terminal of the AND circuit 7, and the output terminal of the AND circuit 7 is connected to the set terminal of the flip-flop 8. On the other hand, a signal line for transmitting a reset signal output from the outdoor unit controller 24 is connected to the reset terminal of the flip-flop 8, and the output terminal of the flip-flop 8 is connected to the drive circuit 9 and the outdoor unit controller 24. ing. The flip-flop 8 is set when both the phase loss detection signal and the overvoltage detection signal are output, and outputs an abnormal state signal indicating this state. On the other hand, this state is reset by a reset signal output from the outdoor unit control unit 24.

図２は各電源ラインに印加される電圧が欠相となった時を示す要部ブロック図である。図２（１）は電源ライン１１（Ａ相電圧）が欠相時、図２（２）は電源ライン１２（Ｂ相電圧）が欠相時、図２（３）は電源ライン１３（Ｃ相電圧）が欠相時をそれぞれ示している。 FIG. 2 is a principal block diagram showing when the voltage applied to each power supply line is lost. 2 (1) is when the power line 11 (A phase voltage) is open, FIG. 2 (2) is when the power line 12 (B phase voltage) is open, and FIG. 2 (3) is the power line 13 (C phase). (Voltage) indicates the time of phase loss.

電源ライン１１のＡ相電圧が欠相し、かつ、過電圧検出部２１が過電圧を検出した場合、つまり、鉄共振が発生した場合、図２（１）に示すようにフィルタ部６はリレー３１とリレー４１とリレー５１のそれぞれのｃ接点に接続される接点をａ接点からｂ接点に切り換える。このため電源ライン１１，１２，１３に接続されているコンデンサ３２，４２，５２が電源トランス２２から切り離されるために鉄共振が停止する。なお、フィルタ部６の動作については後で詳細に説明する。 When the phase A voltage of the power supply line 11 is lost and the overvoltage detection unit 21 detects an overvoltage, that is, when iron resonance occurs, the filter unit 6 is connected to the relay 31 as shown in FIG. The contacts connected to the c contacts of the relay 41 and the relay 51 are switched from the a contact to the b contact. For this reason, since the capacitors 32, 42, 52 connected to the power supply lines 11, 12, 13 are disconnected from the power transformer 22, the iron resonance is stopped. The operation of the filter unit 6 will be described in detail later.

また、コンデンサ３２，４２，５２が電源トランス２２から切り離されると同時に、電源ライン１２から抵抗４３、抵抗５３、電源トランス２２、電源ライン１３に電流が流れるように回路が接続されるため、電源トランス２２に交流電源が供給される回路が形成される。このため、電源トランス２２から電源の供給を受ける制御用電源部２３は直流電圧の供給を継続し、この結果、室外機制御部２４は動作を継続することができる。なお、各リレーの接点が切り換わる約１０ミリセカンドの間は電源トランス２２に電源が供給されないが、制御用電源部２３内には図示しない平滑コンデンサが備えられており、制御用電源部２３は、この切り換えの動作中はこの平滑コンデンサに蓄積された電荷により直流電圧を供給し続ける。 Since the capacitors 32, 42, and 52 are disconnected from the power transformer 22, and the circuit is connected so that current flows from the power line 12 to the resistor 43, resistor 53, power transformer 22, and power line 13, the power transformer A circuit to which AC power is supplied to 22 is formed. Therefore, the control power supply unit 23 that receives power supply from the power transformer 22 continues to supply the DC voltage, and as a result, the outdoor unit control unit 24 can continue to operate. In addition, although power is not supplied to the power transformer 22 for about 10 milliseconds when the contact of each relay is switched, a smoothing capacitor (not shown) is provided in the control power supply unit 23. During the switching operation, the DC voltage is continuously supplied by the electric charge accumulated in the smoothing capacitor.

図２（２）は電源ライン１２のＢ相電圧が欠相した場合を示している。この場合、欠相が発生しても電源トランス２２に直列にコンデンサが接続されることがないため、鉄共振は発生しない。従ってフィルタ部６は、各リレーを切り換えることがないため、リレー３１とリレー４１とリレー５１のそれぞれの接点ｃはａ接点に接続されたままである。このため、直列に接続されたコンデンサ３２とコンデンサ５２が電源ライン１１と電源ライン１３の間に接続された状態のままである。 FIG. 2B shows a case where the phase B voltage of the power supply line 12 is lost. In this case, no iron resonance occurs because a capacitor is not connected in series with the power transformer 22 even if an open phase occurs. Therefore, since the filter unit 6 does not switch each relay, the respective contacts c of the relay 31, the relay 41, and the relay 51 remain connected to the a contact. Therefore, the capacitor 32 and the capacitor 52 connected in series remain connected between the power supply line 11 and the power supply line 13.

電源ライン１３のＣ相電圧が欠相し、かつ、過電圧検出部２１が過電圧を検出した場合、つまり、鉄共振が発生した場合、図２（３）に示すようにフィルタ部６はリレー３１とリレー４１とリレー５１のそれぞれの接点ｃに接続される接点をａ接点からｂ接点に切り換える。このため電源ライン１１，１２，１３に接続されているコンデンサ３２，４２，５２が電源トランス２２から切り離されるために鉄共振が停止する。 When the phase C voltage of the power supply line 13 is lost and the overvoltage detection unit 21 detects an overvoltage, that is, when iron resonance occurs, the filter unit 6 is connected to the relay 31 as shown in FIG. The contact connected to each contact c of the relay 41 and the relay 51 is switched from the a contact to the b contact. For this reason, since the capacitors 32, 42, 52 connected to the power supply lines 11, 12, 13 are disconnected from the power transformer 22, the iron resonance is stopped.

また、コンデンサ３２，４２，５２が電源トランス２２から切り離されると同時に、電源ライン１２から抵抗４３、抵抗３３、電源トランス２２、電源ライン１１に電流が流れるように回路が接続されるため、電源トランス２２に電源が供給される回路が形成される。このため、電源トランス２２から電源の供給を受ける制御用電源部２３は直流電圧の供給を継続し、この結果、室外機制御部２４は動作を継続することができる。 Since the capacitors 32, 42, and 52 are disconnected from the power transformer 22 and the circuit is connected so that current flows from the power line 12 to the resistor 43, resistor 33, power transformer 22, and power line 11, the power transformer A circuit to which power is supplied to 22 is formed. Therefore, the control power supply unit 23 that receives power supply from the power transformer 22 continues to supply the DC voltage, and as a result, the outdoor unit control unit 24 can continue to operate.

図３は本発明による空気調和機の動作を説明する説明図である。図３の横軸は時間を示している。図３の縦軸において、図３（１）は電源ライン１１の電圧（Ａ相電圧）を、図３（２）は電源ライン１２の電圧（Ｂ相電圧）を、図３（３）は電源ライン１３の電圧（Ｃ相電圧）を、図３（４）は欠相検出信号を、図３（５）は過電圧検出信号を、図３（６）は異常状態信号を、図３（７）は各リレーの動作を、図３（８）はリセット信号を、図３（９）は室外機制御部２４の動作をそれぞれ示している。なお、ｔ１〜ｔ７は時刻である。 FIG. 3 is an explanatory view for explaining the operation of the air conditioner according to the present invention. The horizontal axis in FIG. 3 indicates time. 3, FIG. 3 (1) shows the voltage (phase A voltage) of the power supply line 11, FIG. 3 (2) shows the voltage (phase B voltage) of the power supply line 12, and FIG. 3 (3) shows the power supply. 3 (4) shows the phase loss detection signal, FIG. 3 (5) shows the overvoltage detection signal, FIG. 3 (6) shows the abnormal state signal, and FIG. 3 shows the operation of each relay, FIG. 3 (8) shows the reset signal, and FIG. 3 (9) shows the operation of the outdoor unit control unit 24. Note that t1 to t7 are times.

図３（１）に示すように電源ライン１１のＡ相電圧がｔ１〜ｔ５の期間で欠相した場合、欠相検出部２０はｔ１から電源電圧の１／４周期が経過したｔ２でもＡ相電圧を検出できないため、Ａ相電圧の欠相が発生したと判断して図３（４）に示すように欠相検出信号をローレベルからハイレベルにする。また、欠相検出部２０はｔ５から電源電圧の１／４周期が経過したｔ６でＡ相電圧を検出した場合、Ａ相電圧の欠相が終了して電源電圧が復帰したとして図３（４）に示すように欠相検出信号をハイレベルからローレベルにする。 As shown in FIG. 3A, when the phase A voltage of the power supply line 11 is lost during the period from t1 to t5, the phase loss detector 20 detects the phase A even at t2 when a quarter cycle of the power supply voltage has elapsed from t1. Since the voltage cannot be detected, it is determined that the phase loss of the A phase voltage has occurred, and the phase loss detection signal is changed from the low level to the high level as shown in FIG. Further, when the phase loss detection unit 20 detects the A phase voltage at t6 when a quarter cycle of the power supply voltage has elapsed from t5, it is assumed that the phase loss of the A phase voltage has ended and the power supply voltage has been restored as shown in FIG. The phase loss detection signal is changed from the high level to the low level as shown in FIG.

一方、過電圧検出部２１は、電源ライン１１のＡ相電圧がｔ１で欠相となった結果、鉄共振が発生して電源トランス２２の一次側の電圧が所定の瞬時電圧（３８０ボルト）以上となった場合、過電圧が発生したとして図３（５）に示すように過電圧検出信号をｔ３でローレベルからハイレベルにするパルス信号として出力する。 On the other hand, as a result of the phase A voltage of the power supply line 11 being lost at t1, the overvoltage detection unit 21 causes an iron resonance and the voltage on the primary side of the power transformer 22 exceeds a predetermined instantaneous voltage (380 volts). In such a case, the overvoltage detection signal is output as a pulse signal that changes from the low level to the high level at t3 as shown in FIG.

ハイレベルの欠相検出信号と過電圧検出信号が入力されたフィルタ部６のアンド回路７はセット信号をローレベルからハイレベルにすることで、フリップフロップ８の出力である異常状態信号をｔ３でローレベルからハイレベルにセットする。このハイレベルの異常状態信号は室外機制御部２４と駆動回路９に出力されている。このため、室外機制御部２４は異常状態信号により鉄共振の発生を認識できる。 The AND circuit 7 of the filter unit 6 to which the high-level phase loss detection signal and the overvoltage detection signal are input changes the set signal from the low level to the high level, thereby reducing the abnormal state signal output from the flip-flop 8 at t3. Set from level to high. This high level abnormal state signal is output to the outdoor unit controller 24 and the drive circuit 9. For this reason, the outdoor unit control unit 24 can recognize the occurrence of iron resonance from the abnormal state signal.

一方、ハイレベルの異常状態信号が入力された駆動回路９は、リレー駆動信号をローレベルからハイレベルにして各リレーを駆動する。この結果、異常状態信号がハイレベルとなったｔ３から各リレーの動作遅延時間の１０ミリセカンドが経過したｔ４で、各リレーのｃ接点に接続される接点がａ接点からｂ接点に切り換えられて接続される。 On the other hand, the drive circuit 9 to which the high level abnormal state signal is inputted drives each relay by changing the relay drive signal from the low level to the high level. As a result, the contact connected to the c contact of each relay is switched from the a contact to the b contact at t4 when 10 milliseconds of the operation delay time of each relay has elapsed from t3 when the abnormal state signal becomes high level. Connected.

一方、室外機制御部２４はｔ３で異常状態信号が入力されると、インバータ１８の駆動を中止してモータ１９の回転を停止、ユーザーへ欠相発生の報知をするなどの運転停止処理を開始する。そして室外機制御部２４は、欠相検出信号を随時確認して欠相状態終了を監視する。そして室外機制御部２４は、ｔ６で欠相状態終了を認識すると図３（８）に示すようにローレベルからハイレベルに変化するパルス信号であるリセット信号をフィルタ部６のフリップフロップ８へ出力する。 On the other hand, when an abnormal state signal is input at t3, the outdoor unit control unit 24 stops the operation of the inverter 18, stops the rotation of the motor 19, and starts an operation stop process such as notifying the user of the occurrence of a phase loss. To do. Then, the outdoor unit control unit 24 checks the phase loss detection signal at any time and monitors the end of the phase loss state. When the outdoor unit control unit 24 recognizes the end of the phase loss state at t6, it outputs a reset signal, which is a pulse signal that changes from the low level to the high level, to the flip-flop 8 of the filter unit 6 as shown in FIG. To do.

フリップフロップ８はリセット信号が入力されると図３（６）に示すようにｔ６で異常状態信号をハイレベルからローレベルにする。この結果、異常状態信号がローレベルとなったｔ６から各リレーの動作遅延時間の１０ミリセカンドが経過したｔ７で、各リレーのｃ接点に接続される接点がｂ接点からａ接点に切り換えられて接続される。 When the reset signal is input, the flip-flop 8 changes the abnormal state signal from the high level to the low level at t6 as shown in FIG. As a result, the contact connected to the c contact of each relay is switched from the b contact to the a contact at t7 when 10 milliseconds of the operation delay time of each relay has elapsed from t6 when the abnormal state signal becomes low level. Connected.

一方、室外機制御部２４はｔ６で異常状態信号がハイレベルからローレベルになると、欠相状態が終了したとして空調運転を再開させる処理（再起動）を開始して通常運転に復帰する。ただし、ｔ６〜ｔ７は各リレーの動作遅延時間であるため、室外機制御部２４はｔ７で確実に切り換わったことを所定時間の経過で確認してから再起動処理を実行する。 On the other hand, when the abnormal state signal changes from the high level to the low level at t6, the outdoor unit control unit 24 starts the process (restart) for resuming the air-conditioning operation, assuming that the phase loss state has ended, and returns to the normal operation. However, since t6 to t7 are the operation delay times of the respective relays, the outdoor unit control unit 24 executes the restart process after confirming that the switching has been surely performed at t7 after the elapse of a predetermined time.

以上説明したように、空気調和機１は背景技術で説明した高価な容量の大きいコンデンサを電源トランスに並列に接続して鉄共振を防止する構成でなく、安価な小電流用のリレーを用いてコンデンサ３２、４２、５２を電源トランス２２から切り離して鉄共振を防止し、同時に抵抗を用いて交流電源を電源トランス２２に供給する構成であるため、コスト上昇や消費電流の増加を抑制しつつ確実に鉄共振による過電圧発生を防止し、かつ、欠相が発生した場合に緊急処理（運転停止処理）が完了するまで制御用電源部２３を動作させることができる。このため、安全にインバータ１８の動作を停止させたり、図示しないユーザーに異常状態を報知する事ができる。 As described above, the air conditioner 1 is not configured to prevent an iron resonance by connecting an expensive large-capacitance capacitor in parallel with the power transformer described in the background art, but uses an inexpensive small-current relay. Capacitors 32, 42, and 52 are separated from the power transformer 22 to prevent iron resonance, and at the same time, the AC power is supplied to the power transformer 22 using a resistor. Therefore, it is possible to reliably suppress an increase in cost and an increase in current consumption. In addition, it is possible to prevent the occurrence of overvoltage due to iron resonance, and to operate the control power supply unit 23 until the emergency process (operation stop process) is completed when an open phase occurs. For this reason, the operation of the inverter 18 can be safely stopped, or an abnormal state can be notified to a user (not shown).

本実施例では各リレーのａ接点側にコンデンサを、ｂ接点側に抵抗を接続しているが、これに限るものでなく、ａ接点側に抵抗を、ｂ接点側にコンデンサを接続してもよい。ただしこの場合、駆動回路９は鉄共振が発生した時、ｃ接点をａ接点に接続するように制御する。
また、本実施例では室外機制御部２４が異常状態時に運転停止処理を終了した後、再起動のために欠相終了を監視しているが、これに限るものでなく、運転停止処理を終了すると空気調和機１の電源を全て切断するようにしてもよいし、異常状態時に運転停止処理を終了するのでなく、二相運転によりインバータ１８に過度な電流が流れないように圧縮機のモータ１９の回転数を低下させて空調運転を継続してもよい。 In this embodiment, a capacitor is connected to the a contact side of each relay and a resistor is connected to the b contact side. However, the present invention is not limited to this, and a resistor may be connected to the a contact side and a capacitor connected to the b contact side. Good. However, in this case, when the iron resonance occurs, the drive circuit 9 controls to connect the c contact to the a contact.
In this embodiment, after the outdoor unit control unit 24 finishes the operation stop process in an abnormal state, the end of the phase loss is monitored for restart. However, the present invention is not limited to this, and the operation stop process ends. Then, all the power supplies of the air conditioner 1 may be cut off, and the compressor motor 19 may be used so that an excessive current does not flow through the inverter 18 by two-phase operation, instead of terminating the operation stop process in an abnormal state. The air-conditioning operation may be continued by reducing the rotation speed.

さらに、本実施例では電源トランス２２が電源ライン１１と電源ライン１３との間に接続される構成となっているが、電源ライン１１と電源ライン１２との間、または、電源ライン１２と電源ライン１３との間に接続される構成でもよい。いずれの構成であっても、欠相が発生した相以外の相から抵抗を介して電源トランス２２に交流電圧が供給される。
また、本実施例では電源トランス２２は三相のうち二相の電圧が入力される構成になっているが、これに限るものでなく、三相の電圧が入力される構成になっていてもよい。さらに、本実施例では過電圧検出部２１を電源トランス２２の一次側に設けているが、これに限るものでなく、二次側に設けてもよい。 Further, in the present embodiment, the power transformer 22 is connected between the power line 11 and the power line 13, but between the power line 11 and the power line 12, or between the power line 12 and the power line. 13 may be connected. In any configuration, an AC voltage is supplied to the power supply transformer 22 through a resistor from a phase other than the phase where the open phase has occurred.
In the present embodiment, the power transformer 22 is configured to receive two-phase voltages out of three phases, but is not limited thereto, and may be configured to receive three-phase voltages. Good. Furthermore, in this embodiment, the overvoltage detection unit 21 is provided on the primary side of the power transformer 22, but the present invention is not limited to this, and may be provided on the secondary side.

１空気調和機
２室内機
３室外機
６フィルタ部（フィルタ手段）
７アンド回路
８フリップフロップ
９駆動回路
１１電源ライン（第１電源ライン）
１２電源ライン（第２電源ライン）
１３電源ライン（第３電源ライン）
１４入力端
１５入力端
１６入力端
１７直流電源部（第１整流回路）
１８インバータ
１９モータ
２０欠相検出部
２１過電圧検出部
２２電源トランス
２３制御用電源部（第２整流回路）
２４室外機制御部（制御手段）
３１リレー（第３リレー）
３２コンデンサ（第３コンデンサ）
３３抵抗（第３抵抗）
４１リレー（第２リレー）
４２コンデンサ（第２コンデンサ）
４３抵抗（第２抵抗）
５１リレー（第１リレー）
５２コンデンサ（第１コンデンサ）
５３抵抗（第１抵抗） DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Indoor unit 3 Outdoor unit 6 Filter part (filter means)
7 AND circuit 8 Flip-flop 9 Drive circuit 11 Power line (first power line)
12 Power line (second power line)
13 Power line (third power line)
14 input terminal 15 input terminal 16 input terminal 17 DC power supply (first rectifier circuit)
18 Inverter 19 Motor 20 Phase loss detector 21 Overvoltage detector 22 Power transformer 23 Power supply for control (second rectifier circuit)
24 Outdoor unit control unit (control means)
31 Relay (3rd relay)
32 capacitor (third capacitor)
33 Resistance (3rd resistance)
41 Relay (second relay)
42 Capacitor (second capacitor)
43 Resistance (second resistance)
51 Relay (1st relay)
52 Capacitor (first capacitor)
53 Resistance (first resistance)

Claims

A first rectifier circuit connected to a three-phase AC power source composed of an A phase, a B phase, and a C phase, and converting the three-phase AC power source into a DC power source; an inverter to which an output of the first rectifier circuit is input; An outdoor unit including a compressor motor driven by the inverter, and an indoor unit connected to the outdoor unit by communication,
The outdoor unit includes a first power line, a second power line, a third power line, an A phase, a B phase, and a C phase to which the voltages of the A phase, the B phase, and the C phase are applied, respectively. The phase loss detection unit that detects the phase loss of any of the applied voltages and outputs a phase loss detection signal, the power transformer that transforms and outputs the voltage of the three-phase AC power supply, and the power transformer An air conditioner comprising: an overvoltage detection unit that detects an overvoltage of the voltage and outputs an overvoltage detection signal; and a second rectifier circuit that converts the output voltage of the power transformer into a DC voltage and outputs the DC voltage.
The outdoor unit is
The common contacts are connected to each other, and the first relay, the second relay, the third relay, the first resistor, and the first contact or the second contact are switched to be connected to the common contact. Filter means comprising a second resistor, a third resistor, a first capacitor, a second capacitor, and a third capacitor, to which the phase loss detection signal and the overvoltage detection signal are input;
Control means for operating by a DC voltage output from the second rectifier circuit and driving a motor of the compressor via the inverter;
The filter means includes
One end of each of the first capacitor and the first resistor is connected to the first power supply line, the other end of the first resistor is connected to a first contact of the first relay, and the other end of the first capacitor. Is connected to the second contact of the first relay,
One end of each of the second capacitor and the second resistor is connected to the second power supply line, the other end of the second resistor is connected to a first contact of the second relay, and the other end of the second capacitor. Is connected to the second contact of the second relay,
One end of each of the third capacitor and the third resistor is connected to the third power supply line, the other end of the third resistor is connected to a first contact of the third relay, and the other end of the third capacitor Is connected to the second contact of the third relay,
The filter means includes
When the phase loss detection unit detects a phase loss and the overvoltage detection unit detects an overvoltage, an abnormal state signal notifying the occurrence of iron resonance by the power transformer is output to the control means, and The first resistor is connected to the common contact of one relay, the second resistor is connected to the common contact of the second relay, and the third resistor is connected to the common contact of the third relay to stop the iron resonance. ,
The control means includes
When the abnormal state signal is input, it operates using the voltage of the three-phase AC power source transformed by the power transformer via any one of the first resistor, the second resistor, and the third resistor. In addition, the air conditioner is characterized in that the process of stopping the motor drive of the compressor by the inverter or reducing the rotational speed of the motor of the compressor is executed.