CN212210508U

CN212210508U - In-situ reactive power compensation circuit of soft start driving motor

Info

Publication number: CN212210508U
Application number: CN202020543778.8U
Authority: CN
Inventors: 魏兴华; 沈成龙; 宋自用; 王国良
Original assignee: Tongkun Group Co Ltd
Current assignee: Tongkun Group Co Ltd
Priority date: 2020-04-14
Filing date: 2020-04-14
Publication date: 2020-12-22
Anticipated expiration: 2030-04-14

Abstract

The utility model discloses a soft start driving motor's reactive power compensation circuit on spot, including motor M, soft starter RST still includes circuit breaker QF, voltage relay KV, time relay KT, contactor K1, relay K2, condenser C, the leading-out terminal of circuit breaker QF is connected with voltage relay KV's power end and contact COM end, accomplishes the voltage sampling to motor M; the delay closing contact of the time relay KT is connected in series with the normally closed contact of the relay K2. The in-situ reactive compensation circuit of the soft start driving motor carries out in-situ reactive compensation on the motor driven by the soft starter, improves the power factor of a circuit, reduces the current of the circuit, reduces the reactive loss of the circuit, and enables a capacitor to avoid the power supply during soft start and soft stop.

Description

In-situ reactive power compensation circuit of soft start driving motor

The technical field is as follows:

the utility model relates to a soft start driving motor's reactive compensation circuit on spot.

Background art:

the local reactive compensation of the motor is an energy-saving technology widely popularized by the state, and is a simple and effective method for improving the power factor of a line and reducing the electric energy loss, however, when the motor is driven by a soft starter, because the soft starter is used for soft start and soft stop, a large amount of harmonic waves are contained in a power supply output by the soft starter to the motor, and in order to avoid the damage of the harmonic waves to a capacitor, the capacitor is strictly forbidden to be directly connected with the motor in parallel when the soft starter is used. In order to achieve in-situ reactive compensation, it is necessary to prevent motor power from being applied to the capacitor during soft start, soft stop. At present, in industrial and mining enterprises, motors driven by soft start cannot automatically perform on-site reactive compensation.

The utility model has the following contents:

the utility model aims to solve the technical problem that a reliable soft start driving motor's reactive compensation circuit on spot is provided, this soft start driving motor's reactive compensation circuit on spot starts, stops all to go on automatically, does not need manual operation, avoids having the power of strong harmonic to add on the condenser during soft start ware starts, stops.

The technical solution of the utility model is that, a soft start driving motor's reactive power compensation circuit in place is provided, including motor M, soft start RST, still include circuit breaker QF, voltage relay KV, time relay KT, contactor K1, relay K2, condenser C, the leading-out terminal of circuit breaker QF is connected with voltage relay KV's power end and contact COM end, accomplishes the voltage sampling to motor M; the time delay closing contact of the time relay KT is connected with the normally closed contact of the relay K2 in series, the main contact of the contactor K1 is connected with the capacitor C in series, the capacitor C is also connected with the motor M in parallel, the contactor K1 is closed in a time delay mode when starting is completed, and the contactor K1 is not released in a time delay mode when stopping; the normally open contact of the relay K2 is connected in parallel with the normally open contact of the stop button SP of the soft starter RST, so that the self-locking of the electric appliance K2 after starting is realized.

Compared with the prior art after the structure more than adopting, the utility model has the advantages of it is following: the on-site reactive compensation is carried out on the motor driven by the soft starter, the power factor of a line is improved, the current of the line is reduced, the reactive loss of the line is reduced, the capacitor is enabled to avoid power supply during soft start and soft stop, the capacitor can be safely and automatically put into operation, the line is simple, the installation is convenient, the energy is saved obviously, and the popularization and the application are easy.

Preferably, the short-circuit protection fuse FU is also provided for the motor M, and the fuse FU is connected with the motor M and provides a control power supply through a breaker QF.

Description of the drawings:

fig. 1 is a schematic circuit diagram.

The specific implementation mode is as follows:

the invention will be further explained with reference to the drawings and the detailed description below:

as shown in fig. 1, the in-situ reactive power compensation circuit of the soft start driving motor comprises a motor M, a soft starter RST, a breaker QF, a voltage relay KV, a time relay KT, a contactor K1, a relay K2, a capacitor C, wherein a wire outlet end of the breaker QF is connected with a power supply end of the voltage relay KV and a contact COM end to complete voltage sampling of the motor M; the time delay closing contact of the time relay KT is connected with the normally closed contact of the relay K2 in series, the main contact of the contactor K1 is connected with the capacitor C in series, the capacitor C is also connected with the motor M in parallel, the contactor K1 is closed in a time delay mode when starting is completed, and the contactor K1 is not released in a time delay mode when stopping; the normally open contact of the relay K2 is connected in parallel with the normally open contact of the stop button SP of the soft starter RST, so that the self-locking of the electric appliance K2 after starting is realized.

Structurally, the capacitor box is arranged near the site and is very close to the motor and the start-stop button, so that on-site compensation is ensured; cables do not need to be added to the soft driver, a power supply required by work is taken from the motor, an external power supply is not needed, and the circuit is simple and reliable; the start signal is shared with the soft starter and the stop signal is taken from the backup contact of the original motor stop button.

In operation, no operation is needed to be added, the capacitor box does not need an operation button, the original motor is started and stopped by the operation button, the switching of the capacitor is completely and automatically carried out, and equipment faults caused by misoperation cannot occur. For convenient operation, a normally open contact is added on an original soft starter RST stop button SP as a stop signal of a control device. The capacitor power supply is taken from the motor M, the contactor K1 controls the on and off of the capacitor power supply, the fuse FU performs short-circuit protection, and the control power supply is provided through the breaker QF.

The working principle is as follows, after the soft starter RST is started, the voltage on the voltage relay KV in the capacitor box rises along with the voltage rise of the motor M, when the voltage rises to 90% of a rated value, the voltage relay KV acts, an output contact is closed, the time relay KT is electrified, the time relay KT delays to the end of the soft start, the contact of the time relay KT is closed, the contactor K1 is electrified, a main contact of the contactor K1 is closed, the capacitor C is electrified, the capacitor C is connected with the motor M in parallel, reactive power is provided for the motor M, therefore, the line power factor of the motor M is improved, the current is reduced, and the line loss is reduced. If the reactive compensation is needed to be stopped when the motor M operates, the circuit breaker QF is only required to be pulled open, the power supply of the control loop is cut off, the reactive compensation stops working, the reactive compensation is needed to be put into use again, the circuit breaker QF is only required to be closed, the voltage relay KV is electrified, and the work is repeated, so that the reactive compensation is put into operation. When the soft starter stops, namely the stop button SP is pressed down, on one hand, the soft starter slowly reduces the speed after receiving a signal of the stop button SP, on the other hand, the relay K2 is electrified, the contactor K1 is disconnected, the capacitor C is immediately electrified and stops working, at this time, no harmonic wave is added to the capacitor C, the voltage of the motor M and the control power supply slowly reduces, until the voltage reduces to 90% of a rated value, the voltage relay KV acts, the control power supply loses the power, the capacitor box stops working, the soft starter is not influenced to continue to stop, after the soft starter stops, all low-voltage electric appliances return to the initial state, and the next start and stop are waited.

The utility model discloses a carry out reactive compensation on the spot to soft starter driven motor, improve circuit power factor, reduce the line current, reduce circuit reactive loss, make the condenser avoid during soft start and the soft parking electric, can safely, automatically drop into operation again, the circuit is simple, simple to operate, and is energy-conserving obvious, easily popularizes and applies.

The foregoing is illustrative of the preferred embodiments of the present invention only, and is not to be construed as limiting the claims. All the equivalent structures or equivalent flow changes made by using the contents of the specification and the attached drawings of the utility model are included in the patent protection scope of the utility model.

Claims

1. An in-situ reactive power compensation circuit for a soft start driving motor comprises a motor M and a soft starter RST, and is characterized in that: the system also comprises a breaker QF, a voltage relay KV, a time relay KT, a contactor K1, a relay K2 and a capacitor C, wherein the outlet end of the breaker QF is connected with a power supply end of the voltage relay KV and a contact COM end to finish voltage sampling of the motor M; the time delay closing contact of the time relay KT is connected with the normally closed contact of the relay K2 in series, the main contact of the contactor K1 is connected with the capacitor C in series, the capacitor C is also connected with the motor M in parallel, the contactor K1 is closed in a time delay mode when starting is completed, and the contactor K1 is not released in a time delay mode when stopping; the normally open contact of the relay K2 is connected in parallel with the normally open contact of the stop button SP of the soft starter RST, so that the self-locking of the electric appliance K2 after starting is realized.

2. An in-situ reactive compensation circuit for a soft start drive motor of claim 1 wherein: the short-circuit protection fuse FU is connected with the motor M and provides a control power supply through a breaker QF.