Frequency converter fault automatic switching circuit

Abstract

The utility model discloses an automatic switching circuit for frequency converter faults. The automatic switching circuit comprises a first control circuit, a second control circuit, a third control circuit, a fourth control circuit and a fifth control circuit, the utility model has the advantages that when an internal fault occurs in the frequency converter F, automatic switching can be realized through an instantaneous normally open contact of the time relay KT without influencing production, when a maintainer sees an alarm of an indicating lamp HL, the motor M is operated at a power frequency, and meanwhile, a worker operates the change-over switch SA to the power frequency position, so that the maintenance time is shortened. When the switch is switched on, the normally open contact of the change-over switch SA is closed, the normally closed contact is disconnected, the coil of the time relay KT in the third control circuit is disconnected, and the instantaneous normally closed contact of the time relay KT in the second control circuit is in a disconnected state; the coil of the first contactor KM1 continues to be electrified through the change-over switch SA, at the moment, the frequency converter F can be switched out of the power supply loop, the frequency converter F can be overhauled, and normal operation of the motor M is not affected.

Description

Technical Field

[0001] The utility model relates to the technical field of frequency converters, in particular to an automatic switching circuit for frequency converter failures. Background Art

[0002] Internal faults of the inverter are one of the problems that may occur during the operation of the inverter. These faults may be caused by many reasons, including but not limited to overload, overvoltage, undervoltage, overheating, moisture or dust on the circuit board, poor contact, signal interference, etc.

[0003] At present, when an inverter has an internal fault or is damaged during use, it needs to be stopped for repair or replacement, which seriously affects the normal production and reduces work efficiency. Utility Model Content

[0004] The utility model aims to provide an automatic switching circuit for frequency converter failure.

[0005] The utility model is implemented by the following technical scheme: an automatic switching circuit for inverter failure, which includes a first control circuit, a second control circuit, a third control circuit, a fourth control circuit, and a fifth control circuit;

[0006] The first control circuit includes a circuit breaker QF switch, a power stop button SB1, a power start button SB2, and a coil of a first intermediate relay KA1 which are arranged in series in sequence, and the power start button SB2 is connected in parallel with a normally open contact of the first intermediate relay KA1;

[0007] The second control circuit is connected in parallel between the power stop button SB1, the power start button SB2, and the coil of the first intermediate relay KA1 of the first control circuit;

[0008] The second control circuit includes a normally open contact of a first intermediate relay KA1, a normally open contact of a time relay KT, a normally closed contact of a second contactor KM2, a normally closed contact of a thermal relay FR, and a coil of a first contactor KM1, which are sequentially connected in series, and the normally open contact of the time relay KT is connected in parallel with a normally open contact of a conversion switch SA;

[0009] The third control circuit is connected in parallel between the normally open contact of the time relay KT of the second control circuit, the normally closed contact of the second contactor KM2, the normally closed contact of the thermal relay FR, and the coil of the first contactor KM1;

[0010] The third control circuit includes the normally closed contact of the conversion switch SA, the normally closed contact of the first contactor KM1, the coil of the second contactor KM2, and the normally closed contacts 30C-30B of the frequency converter F which are sequentially arranged in series;

[0011] A fourth control circuit is connected in parallel between the normally closed contact of the first contactor KM1 of the third control circuit, the coil of the second contactor KM2, and the normally closed contacts 30C-30B of the frequency converter F;

[0012] The fourth control circuit includes the coil of the time relay KT and the normally open contacts 30A-30B of the frequency converter F which are sequentially connected in series, and the coil of the time relay KT is connected in parallel with an indicator light HL;

[0013] The second control circuit is connected in parallel with the fifth control circuit, and the fifth control circuit includes a frequency converter F stop button SB3, a frequency converter F start button SB4, a normally open contact of the second contactor KM2, and a coil of the second intermediate relay KA2 which are arranged in series in sequence, and the frequency converter F start button SB4 is connected in parallel with the normally open contact of the second intermediate relay KA2.

[0014] The utility model has the following advantages: when an internal fault occurs in the frequency converter F, automatic switching can be achieved through the instantaneous normally open contact of the time relay KT without affecting production. When the maintenance personnel see the alarm of the indicator light HL, the motor M has been running at the industrial frequency. At the same time, the staff operates the conversion switch SA to the industrial frequency position, that is, the normally open contact of the conversion switch SA is closed and the normally closed contact is disconnected, the coil of the time relay KT in the third control circuit is disconnected, and the instantaneous normally closed contact of the time relay KT in the second control circuit is in a disconnected state; through the conversion switch SA, the coil of the first contactor KM1 continues to be energized, and the frequency converter F can be cut out of the power supply circuit at this time, and the frequency converter F can be repaired without affecting the normal operation of the motor M. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is the circuit diagram of the main power circuit of the motor in the utility model;

[0017] Figure 2 This is the automatic switching circuit diagram of the motor in the utility model;

[0018] In the figure: circuit breaker QF, power stop button SB1, power start button SB2, inverter F stop button SB3, inverter F start button SB4, first contactor KM1, second contactor KM2, first intermediate relay KA1, second intermediate relay KA2, inverter F, normally open contacts 30A-30B of inverter F, normally closed contacts 30C-30B of inverter F, switching switch SA, first control circuit 1, second control circuit 2, third control circuit 3, fourth control circuit 4, fifth control circuit 5. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] like Figure 1-2 As shown, the automatic switching circuit of the frequency converter fault includes a first control circuit 1, a second control circuit 2, a third control circuit 3, a fourth control circuit 4, and a fifth control circuit 5;

[0021] The first control circuit 1 includes a circuit breaker QF switch, a power stop button SB1, a power start button SB2, and a coil of a first intermediate relay KA1, which are sequentially arranged in series, and the power start button SB2 is connected in parallel with a normally open contact of the first intermediate relay KA1;

[0022] A second control circuit 2 is connected in parallel between the power stop button SB1, the power start button SB2, and the coil of the first intermediate relay KA1 of the first control circuit 1;

[0023] The second control circuit 2 includes a normally open contact of a first intermediate relay KA1, a normally open contact of a time relay KT, a normally closed contact of a second contactor KM2, a normally closed contact of a thermal relay FR, and a coil of a first contactor KM1, which are sequentially connected in series. The normally open contact of the time relay KT is connected in parallel with a normally open contact of a conversion switch SA.

[0024] A third control circuit 3 is connected in parallel between the normally open contact of the time relay KT of the second control circuit 2, the normally closed contact of the second contactor KM2, the normally closed contact of the thermal relay FR, and the coil of the first contactor KM1;

[0025] The third control circuit 3 includes a normally closed contact of a conversion switch SA, a normally closed contact of a first contactor KM1, a coil of a second contactor KM2, and normally closed contacts 30C-30B of a frequency converter F which are sequentially arranged in series;

[0026] A fourth control circuit 4 is connected in parallel between the normally closed contact of the first contactor KM1 of the third control circuit 3, the coil of the second contactor KM2, and the normally closed contacts 30C-30B of the frequency converter F;

[0027] The fourth control circuit 4 includes a coil of a time relay KT and normally open contacts 30A-30B of a frequency converter F which are sequentially connected in series, and an indicator light HL is connected in parallel to the coil of the time relay KT;

[0028] The second control circuit 2 is connected in parallel with the fifth control circuit 5, which includes a frequency converter F stop button SB3, a frequency converter F start button SB4, a normally open contact of the second contactor KM2, and a coil of the second intermediate relay KA2 which are arranged in series in sequence, and the frequency converter F start button SB4 is connected in parallel with the normally open contact of the second intermediate relay KA2.

[0029] When an internal fault occurs in the frequency converter F, automatic switching can be achieved through the instantaneous normally open contact of the time relay KT without affecting production. When the maintenance personnel see the alarm of the indicator light HL, the motor M is already running at the industrial frequency. At the same time, the staff operates the conversion switch SA to the industrial frequency position, that is, the normally open contact of the conversion switch SA is closed and the normally closed contact is disconnected, disconnecting the coil of the time relay KT in the third control circuit 3, and the instantaneous normally closed contact of the time relay KT in the second control circuit 2 is in the disconnected state; through the conversion switch SA, the coil of the first contactor KM1 continues to be energized, and the frequency converter F can be cut out of the power supply circuit at this time, and the frequency converter F can be repaired without affecting the normal operation of the motor M.

[0030] Turning the transfer switch SA to the industrial frequency operation position in time can achieve non-discriminatory switching;.

[0031] The specific operation process of this embodiment is as follows:

[0032] The model of the inverter F is ACS510. The short circuit between the run and com pins of the inverter F can start the inverter F through the normally open contacts of the second intermediate relay KA2. The fault contacts of the inverter F are normally open contacts 30A-30B, and the fault contacts of the inverter F are normally closed contacts 30C-30B.

[0033] 1. Motor M power supply main circuit:

[0034] 1. The circuit breaker QF switch, the normally open contact of the first contactor KM1, and the thermal relay FR are connected in series to form the power frequency operation circuit of the motor M;

[0035] 2. The switch of the circuit breaker QF, the frequency converter F, and the normally open contact of the second contactor KM2 constitute the frequency converter F operating circuit of the motor M;

[0036] 2. When the motor is normal, the control circuit operation instructions:

[0037] 1. Steps for starting motor M:

[0038] Close the circuit breaker QF switch;

[0039] First control circuit 1: Press the power start button SB2, the coil of the first intermediate relay KA1 is energized and self-locked;

[0040] Third control circuit 3: the normally open contact of the first intermediate relay KA1 is in a closed state, and with the cooperation of the normally closed contact of the conversion switch SA, the coil of the second contactor KM2 is energized;

[0041] Fifth control circuit 5: the normally open contact of the second contactor KM2 is in a closed state, the inverter F start button SB4 is pressed, and the coil of the second intermediate relay KA2 is energized and self-locked;

[0042] Main power supply circuit: The normally open contact of the second intermediate relay KA2 is closed, so that the inverter F is turned on, and the inverter F starts to start the motor M to run;

[0043] 1. Steps to stop motor M:

[0044] First control circuit 1: Press the power stop button SB1, and the coil of the first intermediate relay KA1 loses power;

[0045] The third control circuit 3: Press the stop button SB4 of the frequency converter F, the normally open contact of the first intermediate relay KA1 is in the disconnected state, the coil of the second contactor KM2 loses power, and the power supply of the motor M is disconnected.

[0046] Motor M stops working normally;

[0047] 3. Instructions for control circuit operation when the inverter is abnormal:

[0048] When an internal fault occurs in inverter F, inverter F stops running:

[0049] The third control circuit: the normally closed contacts 30C-30B of the frequency converter F are in the disconnected state, disconnecting the coil circuit of the second contactor KM2;

[0050] Fifth control circuit 5: the normally open contact of the second contactor KM2 is in the disconnected state, the coil circuit of the second intermediate relay KA2 is disconnected, and the start signal of the frequency converter F and the normally open contact of the second intermediate relay KA2 are also in the disconnected state;

[0051] Fourth control circuit 4: the normally open contacts 30A-30B of the frequency converter F are in a closed state, the coil of the time relay KT is energized to start timing, and the indicator light HL starts to alarm;

[0052] Second control circuit 2: The instantaneous normally open contact of the time relay KT is closed, connecting the coil circuit of the first contactor KM1, and the motor M runs at the industrial frequency;

[0053] When the maintenance personnel see the indicator light HL alarm, the motor M is already running at the industrial frequency. At the same time, the staff operates the conversion switch SA to the industrial frequency position, that is, the normally open contact of the conversion switch SA is closed and the normally closed contact is disconnected, disconnecting the coil of the time relay KT in the fourth control circuit 4, and the instantaneous normally closed contact of the time relay KT in the second control circuit 2 is in the disconnected state; through the conversion switch SA, the coil of the first contactor KM1 continues to be energized, and the frequency converter F can be cut out of the power supply circuit at this time, and the frequency converter F can be repaired without affecting the normal operation of the motor M.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The automatic switching circuit for inverter failure is characterized by: It includes a first control circuit, a second control circuit, a third control circuit, a fourth control circuit, and a fifth control circuit; The first control circuit includes a circuit breaker QF switch, a power stop button SB1, a power start button SB2, and a coil of a first intermediate relay KA1 which are arranged in series in sequence, and the power start button SB2 is connected in parallel with a normally open contact of the first intermediate relay KA1; The second control circuit is connected in parallel between the power stop button SB1, the power start button SB2, and the coil of the first intermediate relay KA1 of the first control circuit; The second control circuit includes a normally open contact of a first intermediate relay KA1, a normally open contact of a time relay KT, a normally closed contact of a second contactor KM2, a normally closed contact of a thermal relay FR, and a coil of a first contactor KM1, which are sequentially connected in series, and the normally open contact of the time relay KT is connected in parallel with a normally open contact of a conversion switch SA; The third control circuit is connected in parallel between the normally open contact of the time relay KT of the second control circuit, the normally closed contact of the second contactor KM2, the normally closed contact of the thermal relay FR, and the coil of the first contactor KM1; The third control circuit includes the normally closed contact of the conversion switch SA, the normally closed contact of the first contactor KM1, the coil of the second contactor KM2, and the normally closed contacts 30C-30B of the frequency converter F which are arranged in series in sequence; A fourth control circuit is connected in parallel between the normally closed contact of the first contactor KM1 of the third control circuit, the coil of the second contactor KM2, and the normally closed contacts 30C-30B of the frequency converter F; The fourth control circuit includes a coil of a time relay KT and normally open contacts 30A-30B of a frequency converter F which are sequentially arranged in series, and the coil of the time relay KT is connected in parallel with an indicator light HL; The second control circuit is connected in parallel with the fifth control circuit, and the fifth control circuit includes a frequency converter F stop button SB3, a frequency converter F start button SB4, a normally open contact of the second contactor KM2, and a coil of the second intermediate relay KA2 which are arranged in series in sequence, and the frequency converter F start button SB4 is connected in parallel with the normally open contact of the second intermediate relay KA2.

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