WO2015158218A1

WO2015158218A1 - Motor restarting controller

Info

Publication number: WO2015158218A1
Application number: PCT/CN2015/076265
Authority: WO
Inventors: 程涛
Original assignee: 深圳市倍通控制技术有限公司
Priority date: 2014-04-18
Filing date: 2015-04-10
Publication date: 2015-10-22
Also published as: CN103916053A; CN103916053B

Abstract

A motor restarting controller, which belongs to the technical field of industrial control. The motor restarting controller comprises a logic relay unit (10), a time relay unit (20), a standby power source unit (40) and an output relay (50). The logic relay unit controls the instant closing of an output contact of the output relay when the opening moment of a normally-open auxiliary contact of a contactor or an operation signal contact of a frequency converter is detected. If it is detected that an instant sunken amplitude of a power source voltage reaches a preset amplitude before the opening of the auxiliary contact of the contactor or the opening of the operation signal contact of the frequency converter, the time relay unit controls the opening or closing of a standby power source switch of the output relay within a preset allowed voltage loss time limit so as to control the action mode of the output contact to be instant closing and delay opening within the allowed voltage loss time limit.

Description

Motor restart controller

Technical field

The invention relates to the technical field of industrial control, and in particular to a motor restart controller.

Background technique

AC contactors and frequency converters are commonly used in modern industrial low-voltage motor control loops, and their characteristics are self-sustaining and pressure-free. However, when the motor is running normally, it will encounter the instantaneous voltage loss of the power supply, which will cause the contactor release and the low voltage protection trip of the inverter. When the power supply is automatically restored, it needs to be manually restarted to resume the motor operation, resulting in unnecessary shutdown of the motor during operation. Interruption, which will cause great economic losses to petroleum, petrochemical, chemical, electric power, metallurgical and other continuous production enterprises, and even lead to safety accidents.

With the ring network of the main power grid and the increase of the power supply lines of the piezoelectric network in the enterprise, the enterprise does not set the impedance isolation component to reduce the power consumption. Therefore, when the adjacent network in the main network or the enterprise medium-voltage network is faulty, it is unavoidable. The momentary voltage loss is caused, and the time of the voltage loss depends on the cutting time of the adjacent line fault. The shortest cut-off time for the medium-voltage line short-circuit fault is the transformer's exit saturation time plus the inherent breaking time of the circuit breaker, about 210ms. Most of the instantaneous voltage loss is caused by the fault of the adjacent line. The time is to cut off the fault time, and the voltage loss trip time of the AC contactor should be no more than 3 cycles, that is, less than 60ms.

At present, for the contactor release caused by "shake", since the voltage collection refresh cycle time of the microprocessor is greater than the power supply transient failure time (such as 200ms), the conventional microprocessor-based restart device cannot capture the response quickly. Since the voltage changes instantaneously, the instantaneous voltage loss "shake" for the power supply below 200ms does not work. Therefore, in order to quickly respond to the instantaneous power loss of the power supply below 200ms, it is necessary to avoid the inherent characteristics of the computer data acquisition and refresh cycle, and the non-computer method is adopted, and the prior art does not solve the technical problem.

Summary of the invention

In view of this, the technical problem to be solved by the present invention is to provide a motor restart controller, It solves the problem of quick response to the instantaneous voltage loss of the power supply through non-computer, thus fundamentally solving the problem of contactor release due to sloshing and tripping of the inverter low voltage protection, ensuring that the rotating motor is accelerated after the power is restored.

The technical solution adopted by the present invention to solve the above technical problems is as follows:

The motor restart controller provided by the present invention comprises: a backup power supply unit for supplying power to the controller when the commercial power is instantaneously undervoltage or voltage loss; and a logic relay unit respectively connected to the backup power supply unit, for presetting the time limit a controlled time relay unit and an output relay for providing an output contact, wherein:

The logic relay unit has a pair of power terminals connected to the live line and the neutral line respectively, detecting the instantaneous recessed amplitude of the power supply voltage, and the pair of input terminals are connected with the normally open auxiliary contact of the contactor or the signal contact of the inverter, and the detecting contactor Or the state of the inverter; when the contactor normally open auxiliary contact is detected or the inverter running signal contact is disconnected, the output contact of the control output relay is instantaneously closed; if the instantaneous recessed amplitude of the power supply voltage reaches a preset amplitude, and The output contact is controlled by the time relay unit controlling the opening or closing of the backup power switch of the output relay within the preset allowable voltage loss time limit before the contactor normally open auxiliary contact or the inverter running signal contact is disconnected. The action mode is: within the allowable pressure loss time limit, the instantaneous closing, the delay is broken.

Preferably, the logic relay unit comprises a voltage detecting circuit, a contactor state detecting circuit, a logic determining circuit and a backup power control circuit, wherein:

The voltage detecting circuit has an input end connected to the hot line and the neutral line of the control power source, and detects the instantaneous recessed amplitude of the power supply voltage, and outputs the signal to the logic judging circuit;

The contactor state detecting circuit, the input end is connected with the contactor normally open auxiliary contact or the inverter running signal contact, detecting the state of the contactor normally opening auxiliary contact or the inverter running signal contact, and outputting to the logic judging circuit;

The logic judging circuit determines whether the contactor or the inverter is due to the sloshing cause according to whether the instantaneous sag amplitude of the power supply voltage reaches a preset amplitude and occurs before the contactor normally open auxiliary contact or the inverter running signal contact is disconnected. disconnect;

The backup power control circuit is configured to control whether the backup power switch of the output relay is closed or disconnected according to whether the contactor or the inverter is disconnected due to the swaying cause, and the time relay unit is within the preset allowable voltage loss time limit.

Preferably, the voltage detecting circuit comprises a voltage relay and an auxiliary circuit thereof.

Preferably, the voltage detecting circuit is further configured to detect a momentary change of the voltage. Correspondingly, the logic determining circuit is further configured to: according to whether the instantaneous change amount of the voltage reaches a preset slope, and occurs before the instantaneous recessed amplitude reaches a preset amplitude, Determine if the contactor or inverter is disconnected due to sloshing.

Preferably, the preset amplitude is 45% to 55% of the control power supply voltage, and the preset slope is 10 to 20%.

Preferably, the time relay unit comprises a time relay circuit that cures at least at the factory or cures the time parameter by a digital display device; the time parameter includes a preset allowable pressure loss time limit.

Preferably, the preset allowable voltage loss time limit is 500 milliseconds.

Preferably, the backup power supply unit comprises a built-in capacitor, a first switch control circuit and a second switch control circuit, the first switch control circuit is configured to control whether the controller is powered, and the second switch control circuit is configured to control whether the output relay is powered . Among them, the capacitor is preferably a super capacitor.

Preferably, the controller further comprises an intermediate signal relay unit connected to the backup power unit for providing a time-limited latching contactor or an inverter and an external connection under the control of the logic relay unit in the DCS and PLC signal interlocking control circuit At least one pair of status signals of the output operational status signal of the relay maintains the contact.

The motor restart controller of the embodiment of the invention adopts the relay electronic control mode, and the sacrificial judgment fuzzy control technology which is mutually locked by the analog calculation formula and the logic judgment type, can realize the electrical logic control without a computer program or software. The invention solves the problem of rapid response to the instantaneous voltage loss of the power supply below 200ms, thereby fundamentally solving the problem of the release of the contactor caused by the sloshing, and realizing that the response time to the instantaneous voltage loss of the voltage reaches 0 seconds or more without dead zone.

DRAWINGS

FIG. 1 is a schematic structural diagram of a module of a motor swaying power restart controller according to an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a logic relay unit according to a preferred embodiment of the present invention.

Fig. 3 is a schematic diagram showing an example of wiring of the present invention applied to a contactor.

Fig. 4 is a schematic diagram showing an example of wiring of the present invention applied to a frequency converter.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, in order to make the present invention. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Embodiment 1

As shown in FIG. 1 , a motor sway power restart controller provided by an embodiment of the present invention includes a logic relay unit 10, a time relay unit 20, a backup power unit 40, and an output relay 50, a time relay unit 20, and a backup unit. The power supply unit 40 and the output relay 50 are respectively connected to the backup power supply unit 40, wherein:

The logic relay unit 10 has a pair of power terminals connected to the live line and the neutral line respectively, detecting the instantaneous recessed amplitude of the power supply voltage, and the pair of input terminals are connected with the contactor normally open auxiliary contact or the inverter running signal contact, detecting contact The state of the device or the inverter; when the contactor normally open auxiliary contact is detected or the inverter running signal contact is disconnected, the output contact of the control output relay 50 is instantaneously closed; if the instantaneous recessed amplitude of the power supply voltage reaches a preset amplitude And before the contactor normally open auxiliary contact or the inverter running signal contact is disconnected, the time relay unit 20 is controlled to disconnect the backup power switch of the output relay 50 within a preset allowable voltage loss time limit. Closed to control the output contact action mode: within the allowable pressure loss time limit, instantaneous closing, delay opening.

Specifically, the logic relay unit 10 supplies power to the entire controller loop by controlling the first switch 401 of the backup power supply unit 40, and controls the disconnection of the output relay 50 by the opening and closing of the second switch 401 of the backup power supply unit 40. With closed.

The time relay unit 20 is configured to preset time limit control.

Preferably, the time relay unit comprises a time relay that is solidified at the factory or solidified by a digital display device, and the time parameter is a preset allowable pressure loss time. The preset allowable voltage loss time limit is between 0-20 seconds, preferably 500 milliseconds.

The backup power unit 40 is used to supply power to the controller when the commercial power is instantaneously undervoltage or voltage loss.

Preferably, the backup power unit 40 includes a built-in capacitor, a first switch control circuit 401, and a second The switch control circuit 402 is configured to control whether the controller is powered, and the second switch control circuit 402 is configured to control whether the output relay 50 is powered. Among them, the capacitor is preferably a super capacitor to extend the life of the controller.

An output relay 50 is provided for providing an output relay of the output contact.

Specifically, when the backup power unit switch of the output relay 50 is turned off, the output contact of the output relay 50 is turned off, and when the switch of the backup power unit of the output relay 50 is closed, the output contact of the output relay 50 is closed.

As a preferred solution, the controller further includes an intermediate signal relay unit connected to the backup power unit 40 for providing time-limited latching contact under the control of the logic relay unit 10 in the DCS and PLC signal interlock control circuit. At least one pair of status signals of the output operational status signal of the inverter or the frequency converter and the external relay maintains the contact. Specifically, in the DCS and PLC signal interlock control circuit, under the control of the logic relay unit, the switch of the backup power supply unit of the intermediate signal relay unit is controlled by the time relay unit within a preset allowable voltage loss time limit. Closed or disconnected to limit the output operating status signal of the contactor or the inverter and the external relay.

Embodiment 2

As shown in FIG. 2, a logic relay unit 10 according to a preferred embodiment of the present invention includes a voltage detecting circuit 101, a contactor state detecting circuit 102, a logic determining circuit 103, and a backup power control circuit 104, wherein:

The voltage detecting circuit 101 is connected to the hot line and the neutral line of the control power source, detects the instantaneous recessed amplitude of the power supply voltage, and outputs the voltage to the logic determining circuit 103. The voltage of the control power source can be 220Vac (plug-in type) or 380V (fixed type).

The contactor state detecting circuit 102 is connected to the contactor normally open auxiliary contact or the inverter running signal contact, and detects the state of the contactor normally open auxiliary contact or the inverter running signal contact, and outputs the state to the logic determining circuit 103.

The logic judging circuit 103 determines whether the contactor or the inverter is swayed according to whether the instantaneous recessed amplitude of the power supply voltage reaches a preset amplitude and occurs before the contactor normally open auxiliary contact or the inverter running signal contact is disconnected. The reason is broken.

A backup power control circuit 104 for disconnecting the contactor or the inverter according to the sway On, the time relay unit controls the closing or opening of the backup power switch of the output relay within a preset allowable voltage loss time limit.

Specifically, the voltage detecting circuit 101 includes a voltage relay and its auxiliary circuit.

Preferably, the voltage detecting circuit 101 is further configured to detect a voltage instantaneous change amount. Correspondingly, the logic determining circuit 103 is further configured to: according to whether the instantaneous voltage change amount reaches a preset slope, and the instantaneous concave amplitude reaches a preset amplitude. Before, judge whether the contactor or inverter is disconnected due to the sway. The preset amplitude value is between 45% and 55% of the control power supply voltage, preferably 50% of the control power supply voltage, and the preset slope is between 10% and 20%, preferably 15%.

Embodiment 3

FIG. 3 is a schematic diagram showing an example of the wiring of the present invention applied to the contactor. In the figure, the three-phase coils L1, L2, L3, the three-phase circuit breaker MCCS, the fuse Fuse, the contactor KC, and the motor M form a main circuit. The motor restart controller DZQ-B is connected in parallel to the controller of the contactor KC. The DZQ-B includes 8 contacts, among which:

The first contact and the second contact: the power supply terminal of the logic relay unit of the DZQ-B, the first contact is connected to the live line L11 of the control power supply as the input power of the DZQ-B; the second contact is connected to the neutral line, considering the electronic device. Protection, the 2nd contact should be grounded reliably. The docking point is also a detection point for detecting the change of the L11 power supply voltage, and collects and detects the instantaneous recessed amplitude of the power supply voltage.

The third contact and the fourth contact: are input terminals of the logic relay unit of the DZQ-B, and are connected to a pair of normally open points of the contactor KC. When the contactor KC is sucked, the contactor KC normally connected to the third contact and the fourth contact is closed, and the internal power of the DZQ-B is turned on, indicating that the contactor KC is in the pull-in state, and the motor is normally operated. When the third contact and the fourth contact are disconnected, it is judged that the contactor KC is disconnected, and the logic relay unit of the DZQ-B further determines whether the contactor KC is swayed on the power supply side or is normally tripped, if not caused by sloshing Then, the backup power supply of DZQ-B is immediately released. If it is caused by shaking, the backup power supply delay of DZQ-B is released.

The 5th contact and the 7th contact are the signal output contacts of the DZQ-B and also the dry contacts of the intermediate signal relay unit. The contactor KC is closed after the pull-in is closed. If the contactor is disconnected due to the sloshing, the logic relay unit of DZQ-B controls the 5th contact and the 7th contact to continue to close, and the delay is opened. If the voltage recovers within the preset time, the contactor KC pulls in, the 5th contact and the 7th contact continue to close; if the voltage does not recover within the preset time, Then the 5th contact and the 7th contact are disconnected. If the contactor is not disconnected due to sloshing, the 5th contact and the 7th contact are disconnected.

The 6th contact and the 8th contact: are the output contacts of DZQ-B, and are also the normally open dry contacts of the output relay.

When the contactor KC is disconnected, the logic relay unit of DZQ-B controls the 6th contact and the 8th contact to close immediately, and the running command is blocked for a limited time, and then it is further determined within the time limit whether the contactor KC is broken due to the sloshing. open.

If it is judged that the contactor KC is tripped due to the swaying, the sixth contact and the eighth contact continue to be closed, and the delay is turned off. If it is judged that the contactor KC is not tripped due to the swaying, indicating that it is a normal stop or a faulty stop, the sixth contact and the eighth contact do not perform an action (ie, disconnect), so that no malfunction is caused. It should be noted that the scope of the “limited time” of this paragraph does not exceed the requirements of national or international electrical related regulations.

In this embodiment, the DZQ-B has a pair of output contacts (6th contact and 8th contact) and a pair of output signal contacts (5th contact and 7th contact) interlocked with the DCS. It should be noted that the 5th contact And the 7th contact can be no or as many as needed. The motor restart controller DZQ-B is connected to the contactor anti-sloshing control loop. When the grid is under-voltage “shock”, the DZQ-B provides a delay to the contactor after the AC contactor and the self-holding contact are disconnected. The auxiliary maintenance of the disconnection is based on the contact voltage of the contactor core coil as a voltage threshold value, and is closed again after the power source is restored, thereby maintaining the continuous operation of the motor. Instead of slamming, the contactor is released, and the DZQ-B does not provide an auxiliary hold contact that is delayed.

Embodiment 4

FIG. 4 is a schematic diagram of an example wiring of the present invention applied to a frequency converter. Similar to the third embodiment, the motor restart controller DZQ-BX is connected in parallel to the inverter control circuit, and outputs two pairs of contacts. The main output contact (6-8) is used for the restart command of the inverter and the relay to coincide. The main output contact is only activated after the inverter is running normally. Only when the inverter and relay are tripped due to voltage flashing, the coincidence command is issued, and the call is automatically reset after successful coincidence. The status signal holding contact (5-7) is used to lock the inverter running signal, and the delay is closed after the inverter runs normally. After the inverter and relay are tripped due to voltage flashing, the delay is released. The status signal holding contact (5-7) is released immediately when the inverter is not tripped due to the cause of the voltage drop, and will not be maintained. At the same time, in order to consider in the DCS and PLC signal interlock control inverter circuit, under the control of the logic relay unit, a plurality of pairs of state signal holding contacts for the time-limited latching frequency converter and the output operating state signal of the external relay are provided.

The preferred embodiments of the present invention have been described above with reference to the drawings, and are not intended to limit the scope of the invention. Any modifications, equivalent substitutions and improvements made by those skilled in the art without departing from the scope and spirit of the invention are intended to be included within the scope of the invention.

Industrial applicability

Claims

A motor restart controller, the controller including a backup power unit for supplying power to the controller when the commercial power is instantaneously undervoltage or voltage loss; and a logic relay unit respectively connected to the backup power unit a time relay unit for preset time limit control and an output relay for providing an output contact, wherein:

The logic relay unit has a pair of power terminals connected to the live line and the neutral line respectively, detecting a momentary amplitude of the power supply voltage, and a pair of input terminals are connected with the normally open auxiliary contact of the contactor or the signal contact of the inverter, and detecting The state of the contactor or the inverter; when the contactor normally open auxiliary contact is detected or the inverter running signal contact is disconnected, the output contact of the control output relay is instantaneously closed; if the instantaneous recessed amplitude of the power supply voltage reaches a preset amplitude And occurs before the contactor normally open auxiliary contact or the inverter running signal contact is disconnected, and then the time relay unit controls the opening or closing of the backup power switch of the output relay within a preset allowable voltage loss time limit. The output contact action mode is: instantaneously closed and delayed open within the allowable voltage loss time limit.
The controller of claim 1, wherein the logic relay unit comprises a voltage detecting circuit, a contactor state detecting circuit, a logic determining circuit, and a backup power control circuit, wherein:

The voltage detecting circuit is connected to the hot line and the neutral line of the control power source, and detects the instantaneous recessed amplitude of the power supply voltage, and outputs the signal to the logic determining circuit;

The contactor state detecting circuit, the input end is connected with the contactor normally open auxiliary contact or the inverter running signal contact, detecting the state of the contactor normally open auxiliary contact or the inverter running signal contact, and outputting to the logic determining circuit ;

The logic determining circuit determines whether the contactor or the inverter is based on whether the instantaneous recessed amplitude of the power supply voltage reaches a preset amplitude and occurs before the contactor normally open auxiliary contact or the inverter running signal contact is disconnected Broken due to swaying;

The backup power control circuit is configured to: according to whether the contactor or the inverter is disconnected due to swaying, the relay device controls the backup power switch of the output relay by using the time relay unit within a preset allowable voltage loss time limit Close or open.
The controller of claim 2 wherein said voltage detection circuit comprises a voltage relay and its auxiliary circuit.
The controller according to claim 2, wherein the voltage detecting circuit is further configured to detect a voltage instantaneous change amount, and accordingly, the logic determining circuit is further configured to: according to whether the voltage instantaneous change amount reaches a preset slope And it is determined whether the contactor or the inverter is disconnected due to the swaying current before the instantaneous sag amplitude reaches a preset amplitude.
The controller according to claim 4, wherein said preset amplitude is 45% to 55% of a control power supply voltage, and said predetermined slope is 10 to 20%.
The controller according to claim 1, wherein said time relay unit comprises a time relay circuit that cures at least at the factory or cures a time parameter by a digital display device; said time parameter includes said preset allowable loss Pressure time limit.
The controller of claim 6, wherein the predetermined allowable voltage loss time limit is 500 milliseconds.
The controller of claim 1, wherein the backup power supply unit comprises a built-in capacitor, a first switch control circuit and a second switch control circuit, the first switch control circuit for controlling whether to power the controller, A second switch control circuit is operative to control whether the output relay is powered.
The controller of claim 8 wherein said capacitance is a super capacitor.
A controller according to any one of claims 1-9, wherein said controller further comprises an intermediate signal relay unit connected to the backup power unit for use in the DCS and PLC signal interlock control circuit At least one pair of state signal holding contacts that limit the output operating state signals of the contactor or the frequency converter and the external relay are provided under the control of the logic relay unit.