阅读说明：本技术 一种大型同步电机软启动一拖多控制方法 (Soft start one-to-many control method for large synchronous motor ) 是由 李伟 赵建荣 景采文 薛磊 惠建新 杨东锡 李捷 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种大型同步电机软启动一拖多控制方法：根据不同用电设备的电机启动信号,调用相应电机参数对其大型同步电机进行软启动,并在该电机的启动过程中,使其他尚未进行启动的电机处于闭锁状态,直至实现多个用电设备的大型同步电机的启动,并且实现不同电机软启动的参数自动选择和切换,在避免电机启动对电网和电机自身造成冲击的同时,提高了用电设备的电机启动效率、稳定性,具有适用性广、方便灵活的特点。(The invention discloses a one-driving-more control method for soft start of a large synchronous motor, which comprises the following steps: according to motor starting signals of different electric equipment, corresponding motor parameters are called to carry out soft start on a large synchronous motor of the electric equipment, in the starting process of the motor, other motors which are not started are enabled to be in a locking state until the large synchronous motors of the plurality of electric equipment are started, automatic selection and switching of parameters of the soft start of the different motors are achieved, impact on a power grid and the motors caused by the motor starting is avoided, the motor starting efficiency and stability of the electric equipment are improved, and the electric equipment starting method has the advantages of being wide in applicability, convenient and flexible.)

1. A one-driving-more control method for soft start of a large synchronous motor is characterized by comprising the following steps: the method comprises the following steps:

1) locking starting signals of other motors except the motor to be started;

2) calling a preset parameter group according to the starting signal, and starting the motor to be started according to the called corresponding parameter;

3) and after the starting of the motor to be started is finished or the starting process is stopped, unlocking starting signals of other motors.

2. The one-driving-more control method for the soft start of the large synchronous motor according to claim 1, characterized in that: the step 1) specifically comprises the following steps: the motor controller of the motor to be started sends a starting working signal to the soft starting controller of the soft starter after receiving the starting signal, the locking control relay accessed into the motor controller simultaneously sends a starting locking signal to the corresponding motor controllers of other motors, and the motor controllers of other motors keep the state that the starting working signal is not sent to the soft starting controller after receiving the starting locking signal.

3. The one-driving-more control method for the soft start of the large synchronous motor according to claim 2, characterized in that: the starting signal is a signal sent to a corresponding motor controller by a remote starting control interface of the electric equipment or a starting button of the equipment field; the starting working signal is a signal which is sent by the motor controller after receiving the starting signal and is used for confirming that the soft starter starts to start the corresponding motor to the soft start controller at the same time with the starting locking signal.

4. The one-driving-more control method for the soft start of the large synchronous motor according to claim 1, characterized in that: the step 2) specifically comprises the following steps: when the motor controller of the motor to be started receives the starting signal and sends the starting working signal to the soft starting controller of the soft starter, the soft starting controller selects the starting parameter matched with the motor to be started according to the channel information of the starting working signal received by the soft starting controller, and the motor to be started is started and controlled according to the starting parameter.

5. The one-driving-more control method for the soft start of the large synchronous motor according to claim 4, characterized in that: in the step 2), the soft start controller selects the starting parameters and simultaneously selects the protection parameters matched with the motor to be started, and stops the starting of the motor to be started when the starting process is judged to have a fault according to the protection parameters.

6. The one-driving-more control method for the soft start of the large synchronous motor according to claim 1, characterized in that: the step 3) specifically comprises the following steps: after the motor to be started is started, the soft start controller of the soft starter sends a starting completion signal to the motor controller of the motor to be started, so that the locking control relay connected to the motor controller stops sending starting locking signals to the motor controllers of other motors.

7. A one drags many control system of large-scale synchronous machine soft start which characterized in that: the system comprises a soft start controller, a plurality of motor controllers connected with the soft start controller and a locking control relay independently connected with each motor controller, wherein the locking control relay accessed by any motor controller is respectively connected with other motor controllers;

the locking control relay is used for sending a starting locking signal to other motor controllers when the motor controller connected with the locking control relay sends a starting working signal corresponding to the motor starting signal to the soft starting controller, or stopping sending the starting locking signal to other motor controllers according to a releasing locking signal received by the motor controller connected with the locking control relay;

and after the motor is started or the starting is stopped, the soft start controller sends a locking releasing signal to the corresponding motor controller.

8. The large synchronous motor soft start one-drive-many control system according to claim 7, characterized in that: the soft start controller is switched from the working mode to the standby mode after the motor to be started is started completely or the starting process is stopped, and the soft start controller is switched to the working mode after receiving corresponding starting working signals of other motors in the mode.

9. The large synchronous motor soft start one-drive-many control system according to claim 7, characterized in that: when receiving a starting working signal, the soft start controller determines a channel to which the starting working signal is input, selects and triggers motor control parameters of a corresponding channel according to channel information, performs starting control on the motor, protects the motor once a fault occurs in the starting process, and sends a starting stopping signal to a corresponding motor controller by the soft start controller.

Technical Field

The invention relates to motor soft start control, in particular to one-driving-multiple soft start control of a large synchronous motor for driving electrical equipment such as a compressor, a pump and the like.

Background

The equipment such as large-scale compressors, pumps and the like are widely used in complex chemical engineering processes, the driving parts of the equipment are often realized by large-scale synchronous motors, and in order to maximize the process effect, more and more equipment driven by the motors are used. The starting method of the traditional large synchronous motor mainly comprises self-coupling voltage reduction starting and soft starting. The auto-transformer is required to be arranged for the auto-step-down starting, the impact on a power grid and a motor is large during starting, and the auto-transformer cannot be started frequently, so that the winding of the auto-transformer is prevented from heating, the insulation of the auto-transformer is prevented from being damaged, and the auto-transformer cannot be started by one driving multiple motors. The soft start can be realized by only arranging a soft starter, the impact on a power grid and the motor is small in the starting process of the motor, the reliability is high, the motor can be started frequently, and the starting interval time is short. However, if each motor is equipped with a soft starter, the investment cost is increased. Therefore, Chinese patents CN210536534U, CN102480255A, CN206111507U and CN201584932U construct a one-time system for one-drive-multiple soft start control, and realize sequential start of multiple motors, but the requirements of background adjustment and field control of a process DCS on system flexibility are difficult to meet. Especially, under the condition that the starting sequence and the power of a plurality of large synchronous motors are not uniformly required, the adopted single soft starter is easy to generate faults due to the following conditions, so that the motors cannot be started under the control of the soft starter: when a plurality of motors receive starting signals (for example, some motors are started on site, and some motors are started by a process DCS background), the starting sequence cannot be determined, and thus an error is reported; and secondly, when another motor receives the starting signal in the process of starting one motor, the error is reported because the corresponding control processing can not be carried out according to the signal. In addition, when the starting objects are motors with different powers, the problem that starting and protection requirements of different motors are difficult to be met by single motor control parameter setting is also faced.

At present, a report that one soft starter is adopted to carry out one-to-many control on the soft start of a large synchronous motor is not seen.

Disclosure of Invention

The invention aims to provide a one-driving-more control method for soft start of a large synchronous motor.

In order to achieve the purpose, the invention adopts the following technical scheme:

a one-driving-more control method for soft start of a large synchronous motor comprises the following steps:

1) locking starting signals of other motors except the motor to be started as a condition for starting the motor;

2) calling a preset parameter group according to the starting signal, serving as a basis and guarantee for starting the motor, and starting the motor to be started according to the called corresponding parameters;

3) and after the starting of the motor to be started is finished or the starting process is stopped, unlocking starting signals of other motors.

Preferably, the step 1) specifically comprises the following steps: the motor controller of the motor to be started sends a starting working signal to the soft starting controller of the soft starter after receiving the starting signal, the locking control relay accessed into the motor controller simultaneously sends a starting locking signal to the corresponding motor controllers of other motors, and the motor controllers of other motors keep the state that the starting working signal is not sent to the soft starting controller after receiving the starting locking signal. The invention adds the locking condition in the single motor starting mode adopted by one-drag-one soft starting control, and the motor controller of the motor to be started sends the locking signal to the motor controllers of other motors by using the locking control relay, thereby ensuring that the soft starting controller cannot report errors due to the sending of the starting signals of other motors in the starting process of the motor to be started.

Preferably, the starting signal is a signal sent to the corresponding motor controller through a remote starting control interface (such as a process DCS background) of the electric equipment or a starting button on the equipment site; the starting working signal is a signal which is sent by the motor controller after receiving the starting signal and is used for confirming that the soft starter starts to start the corresponding motor to the soft start controller at the same time with the starting locking signal. I.e. the starting process of the respective motor is started as soon as a starting signal is issued (the motor with the earliest issue time, i.e. the motor to be started) and reaches the soft starter via the motor controller.

Preferably, the step 2) specifically comprises the following steps: when the motor controller of the motor to be started receives the starting signal and sends the starting working signal to the soft starting controller of the soft starter, the soft starting controller selects the starting parameter matched with the motor to be started according to the channel information of the starting working signal received by the soft starting controller, and the motor to be started is started and controlled according to the starting parameter.

Preferably, in the step 2), the soft start controller selects the starting parameter and also selects a protection parameter matched with the motor to be started, and stops starting the motor to be started when the starting process is judged to have a fault according to the protection parameter, so that the problem that the starting of the motors with different sizes is difficult to provide protection due to single protection parameter is solved (the motor controller needs to control excitation, rotating speed, power factor and signals of the motor in the starting process of the motor, the soft start controller controls the rotating speed of the motor to be from zero to rated speed, the excitation is increased and the current is increased in the starting process of the motor, and information for judging whether the motor is normally started is obtained through communication with the motor controller).

Preferably, the step 3) specifically comprises the following steps: after the motor to be started is started, the soft start controller of the soft starter sends a starting completion signal (which can be used for enabling the motor controller to generate a release locking signal) to the motor controller of the motor to be started, so that the locking control relay accessed to the motor controller stops sending a starting locking signal to the motor controllers of other motors, and the other motors have starting conditions (for example, after receiving the starting signal, the motor controller can send a starting working signal to the soft start controller).

Preferably, the soft start controller switches from the working mode to the standby mode after the motor to be started is started completely or the starting process is stopped, and switches to the working mode after the soft start controller receives corresponding starting working signals of other motors in the mode.

A one-driving-multiple control system for soft start of a large synchronous motor comprises a soft start controller, a plurality of motor controllers connected with the soft start controller and locking control relays individually connected with each motor controller, wherein the locking control relays connected with any motor controller are respectively connected with other motor controllers;

the locking control relay is used for sending starting locking signals to other motor controllers when the connected motor controller sends starting working signals corresponding to the motor starting signals to the soft starting controller, or is used for stopping sending starting locking signals to other motor controllers according to the releasing locking signals received by the connected motor controller, so that the locking of the starting signals of other motors is released;

and after the motor is started or the starting is stopped, the soft start controller sends a locking releasing signal to the corresponding motor controller.

Preferably, when one motor is being started, the soft start controller is in a working mode, so that the system does not start the next motor; when the starting of one motor is finished or stopped, the soft start controller is switched to a standby mode to wait for the corresponding starting working signal of the next motor.

Preferably, when a corresponding starting working signal of one motor is received, the soft start controller determines a channel to which the starting working signal is input, selects and triggers motor control parameters (including a starting parameter, a protection parameter and the like) of the corresponding channel according to channel information, can perform starting control on the motor according to the starting parameters, and once a fault occurs in the starting process, can protect the motor according to the protection parameters, and sends a stop starting signal (which can be used for enabling the motor controller to generate a release locking signal) to the corresponding motor controller, and simultaneously sends a motor starting fault signal to a remote starting control interface (such as a process DCS background) of the electric equipment.

The invention has the beneficial effects that:

the invention introduces a starting locking signal on the basis of a motor starting signal as a starting condition for carrying out motor soft starting, avoids the simultaneous starting of a plurality of motors by locking starting signals of other motors, thereby realizing the starting of the motors of a plurality of electric devices (starting the next motor after the starting of one motor is finished) by adopting a soft starting controller (for example, the soft starting controller is contained in one soft starting device), maximizing the utilization rate of the soft starting device, being applicable to carrying out quick and stable one-to-many control on the starting of a large synchronous motor, obviously improving the energy utilization rate and obtaining considerable economic benefit.

Furthermore, different motor control channels are arranged in the soft start controller, so that control parameters of different motors can be selected according to starting signals of different motors, automatic selection and switching of the motor control parameters are realized, configuration and starting requirements of different motors are better met, multiple purposes of one machine (namely one soft starter) can be met, and protection on the starting process can be effectively provided.

Furthermore, the soft start controller can realize the standby state by switching the working mode into the standby mode, and the mode switching of the soft start controller is completely and automatically completed by the controller, so that the damage of the soft start caused by human factors is avoided.

Drawings

FIG. 1 is a schematic diagram of a soft start one-drive-multiple control system of a large synchronous motor (normal start of the motor); in the figures, 1,2,3 …, N indicates the number of the motor and its matched channel.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. The examples are given solely for the purpose of illustration and are not intended to limit the scope of the invention.

Referring to fig. 1, the core of the soft start multi-split control system for the large synchronous motor provided by the invention is an autonomously developed multi-split control mode, which includes setting a locking signal in a starting loop as a condition for starting the motor, and automatically selecting and switching control parameters of the motor to be started. Meanwhile, compared with a one-to-one control mode adopted by the traditional soft start, the interlocking condition and the interlocking action result are increased, and the method specifically comprises the following steps:

(1) a locking control relay is arranged in a one-to-one soft start loop, and a control signal of the locking control relay is sent by a motor controller connected with the locking control relay. When a certain motor (for example, a No. 1 large synchronous motor) needs to be started, a starting button of certain equipment (for example, a large compressor) is clicked at the background or on site of the process DCS, motor starting signals of other equipment are locked by using a locking control relay at the same time, and the motor (the No. 1 large synchronous motor) enters a starting mode.

The locking control relay is independently installed in each large synchronous motor control cabinet; and a starting locking signal circuit for sending locking starting signals of other motors is arranged in each large synchronous motor control cabinet, and the circuit is connected to motor controllers in other large synchronous motor control cabinets. For the established process, the soft starter in each large synchronous motor control cabinet is continuously used, and a controller with multi-channel signal input and processing functions is additionally arranged for parameter selection and switching. For the new forming process, the motor controllers of all the large synchronous motors are connected into the controller (namely the soft start controller) of the same soft starter.

(2) When a starting signal of a motor (No. 1 large synchronous motor) is sent to the soft starter in a working signal form by a motor controller, the controller of the soft starter is converted into a working state, starting parameters of the motor are called and triggered according to a channel for receiving the starting working signal, the motor is started by using the parameters, the motor is protected during starting, fault judgment is carried out by using the protection parameters, and the motor damage caused by faults is avoided by stopping the starting process. When the fault is eliminated, the starting mode can be entered according to the step 1).

(3) After the motor (large synchronous motor No. 1) is started, the motor is switched to operate frequently, a controller of the soft starter is switched to a standby state (standby state), and meanwhile, a starting completion signal is generated by the controller of the soft starter, so that the controller of the motor (large synchronous motor No. 1) releases a locking signal (namely, a locking control relay which is controlled to be connected does not send a starting locking signal any more), and other motors can enter a starting mode.

(4) Under the running condition of a motor (No. 1 large synchronous motor), if the motor receives a starting signal again, the controller of the soft starter is locked and cannot start the motor again, and the starting working signals of other motors cannot be influenced because the controller of the motor releases the locking signal.

The invention is applied to the starting control of a primary machine and a secondary machine of an LDPE/EVA device (namely the number of motors N is 2; primary power 6100kW and secondary power 25900kW), and is also applicable to the starting of a plurality of large synchronous motors under the condition of other motors (for example, according to the specification of a latching relay, the soft starting of one motor with a plurality of motors can be realized).

In a word, the invention sets a locking control relay in a starting loop, takes starting signals and relay signals (locking signals) of different motors as the starting conditions of the motors, when a certain motor is started, the locking signals are released, and a system can receive starting signals of other motors, thereby realizing the independent selection of starting orders of different motors under the control of one-driving-more soft starting; meanwhile, the invention can select the control parameters of different motors according to the starting signals of different motors and by using different channels of the soft start controller, realizes the automatic switching of the parameters of the soft start of different motors, and has the characteristics of wide applicability, convenience and flexibility. The practical application result shows that the invention has the following advantages:

(1) the invention realizes one-driving-multiple control of the large synchronous motor, can automatically switch the control parameters of the motor in the control process, and has the characteristics of wide applicability, convenience and flexibility.

(2) On the basis of a one-to-one control system, the invention leads the developed one-to-many control system to be simple and practical by introducing the locking control relay and the corresponding circuit, thereby saving the investment and reducing the occupied area of the distribution room equipment.

(3) The invention adopts a one-to-many control mode for starting the large synchronous motor, when one motor is selected to be started, the starting signals of other motors are automatically locked, the motors of a plurality of devices cannot be started simultaneously, and thus the faults of the soft starter are reduced.

(4) The invention uses a soft starter to directly drag the large synchronous motor from zero rotating speed to power frequency rotating speed, ensures that each motor finishes normal starting within 17-20 s, reduces the electric quantity loss when equipment is started, improves the starting efficiency and stability of a plurality of motors, reduces the failure rate of electric equipment, and brings considerable economic benefit.