阅读说明：本技术 并联型三相交流接触器的自适应同步控制方法 (Self-adaptive synchronous control method of parallel three-phase alternating current contactor ) 是由 许志红 张槟鑫 于 2019-10-12 设计创作，主要内容包括：本发明涉及一种并联型三相交流接触器的自适应同步控制方法,包括以下步骤：步骤S1:检测各个接触器线圈电压,判断控制回路是否电源正常；步骤S2:当达到上电范围时,进入合闸过程,之后将触头电压采样通道打开,对各个接触器触头电压相位进行检测；步骤S3:对合闸过程进行同步控制,考虑合闸顺序带来的电压相位变化,最终使得各相接触器能在所选相位同步合闸;步骤S4:当线圈电压检测判断控制回路电源处于下电范围时,进入分闸过程,对各相内并联连接的各支路接触器的分断顺序进行动态调整;步骤S5:将软件延时与机构固有分断时间相配合来设定分闸指令步骤S6:将自适应动态调整策略加入接触器的零电流分闸控制和同步分断控制过程。本发明实现并联型三相交流接触器通断过程的同步。(The invention relates to a self-adaptive synchronous control method of a parallel three-phase alternating current contactor, which comprises the following steps of: step S1, detecting the voltage of each contactor coil, and judging whether the power supply of the control loop is normal; step S2, when the power-on range is reached, the switching-on process is started, then the contact voltage sampling channel is opened, and the contact voltage phase of each contactor is detected; the method comprises the steps of S3, synchronously controlling a switching process, considering voltage phase change caused by a switching sequence, and finally enabling each phase contactor to be synchronously switched on at a selected phase, S4, entering the switching process when coil voltage detection judges that a control loop power supply is in a power-off range, and dynamically adjusting the breaking sequence of each branch contactor connected in parallel in each phase, S5, setting a switching-off command step S6 by matching software delay with the inherent breaking time of a mechanism, and adding an adaptive dynamic adjustment strategy to the zero-current switching-off control and synchronous breaking control processes of the contactors. The invention realizes the synchronization of the on-off process of the parallel three-phase alternating current contactor.)

1. a self-adaptive synchronous control method of a parallel three-phase alternating current contactor is characterized by comprising the following steps:

step S1, detecting the voltage of each contactor coil of the parallel three-phase AC contactor, and judging whether the power supply of the control loop is normal;

Step S2, when the power-on range is reached, the switching-on process is started, then the contact voltage sampling channel is opened, and the contact voltage phase of each contactor is detected;

Step S3, synchronously controlling the closing process of the parallel three-phase alternating current contactor, and finally enabling each phase contactor to be synchronously closed at the selected phase by considering the voltage phase change caused by the closing sequence;

Step S4, when the coil voltage detection judges that the control loop power supply is in the power-off range, entering the brake-off process, and dynamically adjusting the breaking sequence of each branch contactor connected in parallel in each phase;

Step S5, the software delay is matched with the inherent breaking time of the mechanism to set a brake-separating instruction, so as to achieve the control of zero current breaking;

and step S6, adding the self-adaptive dynamic adjustment strategy into the zero-current switching-off control and synchronous breaking control process of the contactor, so that each phase of contactor can be stabilized in the zero-current breaking area to realize successful synchronous switching-off.

2. The adaptive synchronous control method of a parallel three-phase ac contactor according to claim 1, wherein the step S3 specifically comprises:

S31, separately controlling the closing instruction of each phase contact and the closing instruction of each phase contactor connected in parallel, wherein the closing instruction of each phase contactor is used for matching the software delay with the mechanism action time;

step S32, voltage phase changes at two ends of each phase contactor caused by different closing sequences in the closing process are considered, so that each phase contactor can close at the selected phase;

And step S33, the closing instruction of the contactors connected in parallel in each phase is effective only after the closing instruction of the contactors in each phase is sent out, and the closing instruction is used for synchronous suction control of the contactors on the branches connected in parallel, so that synchronous and same-phase closing operation of the contactors on the branches in each phase is realized.

3. The adaptive synchronous control method of a parallel three-phase ac contactor according to claim 1, wherein the step S5 specifically comprises:

Step S51: dividing each branch contactor connected in parallel into a breaking sequence adjusting phase and a breaking moment adjusting phase;

step S52, extracting the breaking sequence and the breaking moment characteristic quantity of each branch contactor connected in parallel in each phase by detecting the occurrence process of the current transfer phenomenon, and identifying the breaking sequence of each branch contactor on line;

and step S53, during adjustment, the breaking moment adjusting phase is not changed, the breaking moment value of the breaking sequence adjusting phase is continuously adjusted to be close to the breaking moment value of the breaking moment adjusting phase, and finally the breaking moment error of the contactors on each branch circuit does not exceed a preset value, so that zero-current breaking control is achieved.

4. the adaptive synchronous control method of a parallel three-phase ac contactor according to claim 1, wherein the step S6 specifically comprises:

step S61, judging whether the breaking time of the breaking time adjusting phase needs to be adjusted on line by detecting the occurrence time of the current transfer phenomenon;

and step S62, during adjustment, the breaking time adjustment phase and the breaking sequence adjustment phase change the breaking time by the same variable quantity, the adjustment process is accelerated, and the synchronism of the branch contactors in the adjustment process is ensured, so that the zero-current brake control can be adaptively adjusted along with the action characteristic change caused by contact wear and spring aging after the contactors operate for a long time, and the breaking time of each contactor in three phases is always kept in a zero-current breaking area.

Technical Field

The invention relates to the technical field of low-voltage appliances, in particular to a self-adaptive synchronous control method of a parallel three-phase contactor.

Background

along with the maximization of processing equipment, heavy machinery is widely used in industrial control occasions such as coal, metallurgy, mines and the like, so that the requirement of a high-capacity alternating current contactor on the industrial control occasions is increased, in addition, the continuous development of national economy and electrical industry and the improvement of social electricity consumption drive the continuous expansion of the scale of a power grid, a power system is subjected to self capacity expansion and internet interconnection, the system structure tends to be more complicated, the current passing under normal conditions is increased, the frequency of short-circuit faults and the numerical value of short-circuit fault current are improved, and the capacity of a power distribution system is also improved. In order to meet the requirements of the new energy field, the industrial control field, the self capacity expansion of the power grid and other occasions on a high-capacity alternating current contactor, particularly the requirement on the alternating current contactor with the current specification of more than 630A, the problem that the rated capacity of a boost switch is a hotspot is solved. Because the bottleneck problems in the aspects of contact materials and contact structures of the contactor are difficult to break through, the rated current capacity and the breaking capacity of the contactor with the single fracture are difficult to be improved from the body, and therefore a method for realizing the capacity expansion operation of the alternating current contactor under the condition of not changing the contact structures and the materials is urgently needed to be found.

For power switches with a rated current greater than 1000A, several rated currents are often used to simplify the manufacturing process

the small switch electric appliance improves the through-current capacity and the breaking current grade thereof in a mode that contacts are connected in parallel, and comprises a commonly used protection electric appliance and a control electric appliance, and a large-capacity circuit breaker, a contactor, a knife isolating switch and a fuse are commonly connected in parallel by a plurality of poles to improve the rated current capacity so as to realize capacity expansion operation.

in the field of high-voltage circuit breakers, the multi-break circuit breaker series technology becomes an effective solution for application in occasions with higher voltage levels, researchers at home and abroad carry out deep research on static and dynamic insulation characteristics, breaking gain characteristics, dynamic voltage sharing and operating mechanisms of multi-break circuit breakers at present, and Beijing switchhouses, university of great chain engineering and Western Ann traffic university all develop multi-break series circuit breaker products, so that the breaking capacity of the circuit breaker is greatly improved.

disclosure of Invention

in view of the above, an object of the present invention is to provide an adaptive synchronous control method for a parallel three-phase ac contactor, which achieves synchronization of actions of contactors in each phase, and completes adaptive zero-current breaking control of contactors in each phase during phased closing and breaking of the three-phase contactor.

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

A self-adaptive synchronous control method of a parallel three-phase alternating current contactor comprises the following steps:

Step S1, detecting the voltage of each contactor coil of the parallel three-phase AC contactor, and judging whether the power supply of the control loop is normal;

step S2, when the power-on range is reached, the switching-on process is started, then the contact voltage sampling channel is opened, and the contact voltage phase of each contactor is detected;

Step S3, synchronously controlling the closing process of the parallel three-phase alternating current contactor, and finally enabling each phase contactor to be synchronously closed at the selected phase by considering the voltage phase change caused by the closing sequence;

step S4, when the coil voltage detection judges that the control loop power supply is in the power-off range, entering the brake-off process, and dynamically adjusting the breaking sequence of each branch contactor connected in parallel in each phase;

Step S5, the software delay is matched with the inherent breaking time of the mechanism to set a brake separating instruction, and the phase change of other two-phase current is considered after the first-open phase is disconnected so as to achieve the control of zero current breaking;

and step S6, adding the self-adaptive dynamic adjustment strategy into the zero-current switching-off control and synchronous breaking control process of the contactor, so that each phase of contactor can be stabilized in the zero-current breaking area to realize successful synchronous switching-off.

further, the step S3 is specifically:

S31, separately controlling the closing instruction of each phase contact and the closing instruction of each phase contactor connected in parallel, wherein the closing instruction of each phase contactor is used for matching the software delay with the mechanism action time;

Step S32, voltage phase changes at two ends of each phase contactor caused by different closing sequences in the closing process are considered, so that each phase contactor can close at the selected phase;

and step S33, the closing instruction of the contactors connected in parallel in each phase is effective only after the closing instruction of the contactors in each phase is sent out, and the closing instruction is used for synchronous suction control of the contactors on the branches connected in parallel, so that synchronous and same-phase closing operation of the contactors on the branches in each phase is realized.

Further, the step S5 is specifically:

Step S51: dividing each branch contactor connected in parallel into a breaking sequence adjusting phase and a breaking moment adjusting phase;

Step S52, extracting the breaking sequence and the breaking moment characteristic quantity of each branch contactor connected in parallel in each phase by detecting the occurrence process of the current transfer phenomenon, and identifying the breaking sequence of each branch contactor on line;

And step S53, during adjustment, the breaking moment adjusting phase is not changed, the breaking moment value of the breaking sequence adjusting phase is continuously adjusted to be close to the breaking moment value of the breaking moment adjusting phase, and finally the breaking moment error of the contactors on each branch circuit does not exceed a preset value, so that zero-current breaking control is achieved.

further, the step S6 is specifically:

Step S61, judging whether the breaking time of the breaking time adjusting phase needs to be adjusted on line by detecting the occurrence time of the current transfer phenomenon;

and step S62, during adjustment, the breaking time adjustment phase and the breaking sequence adjustment phase change the breaking time by the same variable quantity, the adjustment process is accelerated, and the synchronism of the branch contactors in the adjustment process is ensured, so that the zero-current brake control can be adaptively adjusted along with the action characteristic change caused by contact wear and spring aging after the contactors operate for a long time, and the breaking time of each contactor in three phases is always kept in a zero-current breaking area.

compared with the prior art, the invention has the following beneficial effects:

the invention realizes the synchronism of the actions of each contactor which is subjected to capacity expansion operation in each phase and simultaneously completes the phased closing of the three-phase contactor and the self-adaptive zero-current breaking control of each phase contactor in the breaking process.

Drawings

Fig. 1 is a block diagram of a switching-on/off synchronous control method with a self-adaptive adjustment function according to an embodiment of the present invention;

fig. 2 shows waveforms of voltage and current in a breaking process of a contactor connected in parallel with each branch circuit in an embodiment of the invention.

Detailed Description

The invention is further explained below with reference to the drawings and the embodiments.

Referring to fig. 1, the present invention provides a method for adaptive synchronous control of a parallel three-phase ac contactor, in fig. 1, six unipolar contactors are connected in parallel to form a parallel three-phase ac contactor, where IA, IB, and IC are three-phase main currents, IA1 and IA2 are a parallel branch currents, IB1 and IB2 are B parallel branch currents, and IC1 and IC2 are C parallel branch currents; kxx represents a contactor on each parallel branch, for example KA1 represents a contactor on A parallel branch 1; the method comprises the following steps:

step S1, detecting the voltage of each contactor coil of the parallel three-phase AC contactor, and judging whether the power supply of the control loop is normal;

step S2, when the power-on range is reached, the switching-on process is started, then the contact voltage sampling channel is opened, and the contact voltage phase of each contactor is detected;

Step S3, synchronously controlling the closing process of the parallel three-phase alternating current contactor, and finally enabling each phase contactor to be synchronously closed at the selected phase by considering the voltage phase change caused by the closing sequence;

Step S4, when the coil voltage detection judges that the control loop power supply is in the power-off range, entering the brake-off process, and dynamically adjusting the breaking sequence of each branch contactor connected in parallel in each phase;

step S5, the software delay is matched with the inherent breaking time of the mechanism to set a brake separating instruction, and the phase change of other two-phase current is considered after the first-open phase is disconnected so as to achieve the control of zero current breaking;

and step S6, adding the self-adaptive dynamic adjustment strategy into the zero-current switching-off control and synchronous breaking control process of the contactor, so that each phase of contactor can be stabilized in the zero-current breaking area to realize successful synchronous switching-off.

In this embodiment, the step S3 specifically includes:

s31, separately controlling the closing instruction of each phase contact and the closing instruction of each phase contactor connected in parallel, wherein the closing instruction of each phase contactor is used for matching the software delay with the mechanism action time;

Step S32, voltage phase changes at two ends of each phase contactor caused by different closing sequences in the closing process are considered, so that each phase contactor can close at the selected phase;

and step S33, the closing instruction of the contactors connected in parallel in each phase is effective only after the closing instruction of the contactors in each phase is sent out, and the closing instruction is used for synchronous suction control of the contactors on the branches connected in parallel, so that synchronous and same-phase closing operation of the contactors on the branches in each phase is realized.

In this embodiment, the step S5 specifically includes:

Step S51: dividing each branch contactor connected in parallel into a breaking sequence adjusting phase and a breaking moment adjusting phase;

Step S52, extracting the breaking sequence and the breaking moment characteristic quantity of each branch contactor connected in parallel in each phase by detecting the occurrence process of the current transfer phenomenon, and identifying the breaking sequence of each branch contactor on line;

And step S53, during adjustment, the breaking moment adjusting phase is not changed, the breaking moment value of the breaking sequence adjusting phase is continuously adjusted to be close to the breaking moment value of the breaking moment adjusting phase, and finally the breaking moment error of the contactors on each branch circuit does not exceed a preset value, so that zero-current breaking control is achieved.

In this embodiment, the step S6 specifically includes:

Step S61, judging whether the breaking time of the breaking time adjusting phase needs to be adjusted on line by detecting the occurrence time of the current transfer phenomenon;

And step S62, during adjustment, the breaking time adjustment phase and the breaking sequence adjustment phase change the breaking time by the same variable quantity, the adjustment process is accelerated, and the synchronism of the branch contactors in the adjustment process is ensured, so that the zero-current brake control can be adaptively adjusted along with the action characteristic change caused by contact wear and spring aging after the contactors operate for a long time, and the breaking time of each contactor in three phases is always kept in a zero-current breaking area.

In this embodiment, taking a three-phase delta-connected load as an example, let the a-phase voltage beAssuming that the A-phase voltage is at t₁The time firstly crosses zero, defined as the first phase, then when the A phase is in the required phasewhen the contactor is closed, the voltage at two ends of the contact of the C-phase contactor is as follows:

i.e. closed phase lag phase A of phase Cand after the A-phase and B-phase switches are closed, the voltages at two ends of the contact of the B-phase contactor are as follows in the same way:

i.e. closed phase lag phase A of phase B。

Therefore, the phased closing process of each phase contactor is when A phase t₁after the zero point is detected at the moment, the time t is delayed through software₂a closing instruction is sent out, the contact starts to act, and the inherent action time of the mechanism is withinphase angle closed, with phase C in extended lag phase AThe closing instruction is sent out after the time corresponding to the phase angle, and the phase B lags behind the phase A after being prolongedSending a closing instruction after the time corresponding to the phase angle, setting the zero point to be detected as the zero point changed from the negative half-wave of the voltage to the positive half-wave, when one phase contactor firstly detects the zero point, judging the action sequence according to the positive and negative half-waves of the voltage at two ends of the contact at the time by the other two phase contactors, wherein the positive half-wave is the second phase closing and the negative half-wave is the third phase closing, the software time delay of each phase contactor is matched with the pull-in time of the contactor, and finally, the three phase contactors are all in phaseand (5) closing. And it is analyzed that if phase a detects a zero point, the contactor closing sequence must be A, C, B. If phase B detects a zero point, the closing sequence must be B, A, C. If phase C first detects a zero point, the closing sequence must be C, B, A.

when synchronous closing control of contactors on each branch circuit connected in parallel in each phase is performed, the voltage phase amplitudes of the two ends of the contact of each branch circuit contactor are equal, so that the setting of a closing instruction is determined only by matching with the pull-in time of each branch circuit switch, and the closing instruction is effective only after the closing instruction of each phase contactor is sent out. When a certain branch voltage detects a zero point, a closing instruction is sent out through software delay, and the software delay set by the contactor of the other branch is adjusted according to the action time of the branch, so that the total time of the software delay passed by the contactor of each branch and the inherent action time of the mechanism is equal, and the synchronous closing operation is achieved. The synchronous closing instruction of the contactors on each parallel branch is combined with the phased closing instruction control of each phase contactor through a logic gate circuit on a synchronous closing module, and the electrifying signal and the closing instruction of each contactor are subjected to related control, so that errors caused by inconsistency of hardware circuit response are eliminated.

the parallel three-phase contactor zero current switching principle is similar to the phased switching, and the switching command is set by matching the software delay with the inherent breaking time of the mechanism when one phase of the zero point is detected, so that the control of zero current breaking is achieved. After the first phase is disconnected, different from the closing process, the current phase of other two-phase circuits changes due to the fact that the other two-phase circuits are changed into the same main circuit, software delay correspondingly changes, and the two-phase contactors are disconnected at the same moment.

Considering that the action characteristics of the contactor change due to the contact abrasion, the aging of a spring and the like after the contactor operates for a long time, the self-adaptive dynamic adjustment strategy is added into the zero-current switching-off control and synchronous breaking control process of the contactor, so that each phase of contactor can be stabilized in a zero-current breaking area to realize successful synchronous switching-off.

the specific scheme is as follows: and taking the contactor on one branch as a breaking sequence adjusting phase, and taking the other branch as a breaking moment adjusting phase.

After the first-open phase is separated, the current of the branch circuit is completely transferred to other parallel branch circuits, namely, a current transfer phenomenon occurs, the current transfer phenomenon is shown in figure 2, the breaking time of the first-open phase and the breaking sequence of the branch circuit contactors can be judged by detecting the occurrence time of the current transfer phenomenon, the breaking time and the breaking sequence of the branch circuit contactors are stored in an EEPROM and compared with a preset zero-current breaking area, and whether the breaking time needs to be adjusted on line or not is judged in real time. Considering the influence of the dispersion of the operation, the order of the disconnection is adjusted only when it is detected that the contactor in one branch is in the first-open phase for a long period of time. During adjustment, the breaking time of the breaking time adjusting phase is not changed, the breaking time of the breaking sequence adjusting phase is subjected to forward adjustment in a change of 0.1ms until the contactor becomes a new first-open phase, if the contactor becomes the first-open phase for a long time, the breaking time of the contactor is still subjected to delay adjustment in a change of 0.1ms until the contactor becomes a non-first-open phase, and the breaking time of the contactor of the breaking sequence adjusting phase is kept basically consistent with the breaking time of the contactor on the other branch in a circulating manner, and the error of the breaking time of the contactor and the breaking time of the contactor on the other branch is not more than 0.1 ms. The function of the breaking moment adjusting phase is that if the moment of the current transfer phenomenon is detected to occur after the zero point, namely the zero current control is failed, the breaking moment of each branch contactor is not in the zero current breaking area, the breaking moment data stored in the EEPROM in real time is still read, the breaking moment adjusting phase and the breaking sequence adjusting phase are adjusted by the same variable quantity, the adjusting process is accelerated, the synchronism of the branch contactors in the adjusting process is ensured, until the breaking moment of each phase contactor is adjusted in the zero current breaking area, the breaking sequence adjusting phase still adjusts the breaking moment to be consistent with the breaking moment adjusting phase through the dynamic adjusting process of the sequence, namely each branch contactor can follow the action characteristic change, and the breaking is kept in the zero current breaking area through the dynamic adjustment of the self-adaptive breaking sequence and the breaking moment, and the condition that the contactor on one branch becomes the first-open phase for a long time is avoided.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.