CN209963973U - Motor driving system for central air conditioner - Google Patents
Motor driving system for central air conditioner Download PDFInfo
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- CN209963973U CN209963973U CN201920647736.6U CN201920647736U CN209963973U CN 209963973 U CN209963973 U CN 209963973U CN 201920647736 U CN201920647736 U CN 201920647736U CN 209963973 U CN209963973 U CN 209963973U
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Abstract
The utility model discloses a motor driving system for a central air conditioner, wherein the motor at least comprises 2 groups of windings, a current transformer and a soft starter are sequentially arranged on a main loop from an inlet wire end to the motor, at least one contactor is arranged on the main loop between the motor and the current transformer in a parallel connection way with the main loop, and an access point of the contactor on the main loop is positioned between the soft starter and the current transformer; the contactor and the soft starter are both connected with the PLC; the contactor is connected with a low-speed winding wiring terminal of the motor, and the soft starter is connected with a high-speed winding wiring terminal of the motor. The motor starting device can be suitable for the field requirement of frequent starting, prolongs the service life of the motor, and simultaneously ensures excellent starting effect and safety protection.
Description
Technical Field
The utility model relates to a motor drive system, concretely relates to central air conditioning is with motor drive system.
Background
In the refrigeration and heating air conditioning industry applications, it is often desirable that the motor of the compressor be capable of two-speed (multi-speed) operation. The starting and running means of the commonly used double-speed (multispeed) motor comprises contactor driving, frequency converter driving, double soft starter driving and single soft start contactor driving. The contactor drives to realize the star-delta starting and high-low speed switching of the motor, secondary current impact exists in the starting process of the scheme, the cost is high, the structure is complex, and the failure rate is high; although the scheme of realizing motor starting and high-low speed switching by driving the frequency converter has no secondary current impact in the starting process, small starting current and smooth starting, the scheme has high cost; the double-soft-starter driving scheme shares the starting operation of the motor winding to the two soft starters, the starting of the motor winding is soft starting, secondary impact does not exist in the starting, the starting is smooth, and the scheme is high in cost.
There is also a traditional two-speed (multi-speed) motor drive, which uses a single soft starter plus contactor scheme, generally using one soft starter, then configuring two (multiple) contactors, when starting, closing one contactor first, then starting the soft starter, when stopping, stopping the soft starter first and then releasing the contactor. The soft starter has requirements on the starting times in a unit hour, if the scheme is frequently required on site to cause damage to the soft starter, the current requirement is high when the soft starter drives a high speed, the current requirement is low when the soft starter drives a low speed, the starting parameters are different from the starting current limit, the protection parameters are also different, and the soft starter can not reliably protect a motor and control a starting curve. Meanwhile, a plurality of contactors are needed, wiring is complex, and cost is high.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model is, to starting frequent site requirement double speed or the many fast motors frequently start, stronger safety protection and good start-up curve's technical demand, provide a central air conditioning motor drive system, can be applicable to and start frequent site requirement, extension motor life guarantees good start-up effect and safety protection simultaneously.
In order to solve the technical problem, the utility model adopts the following technical scheme:
a motor driving system for a central air conditioner is characterized in that: the motor at least comprises 2 groups of windings, a current transformer and a soft starter are sequentially arranged on a main loop from a line inlet end to the motor, at least one contactor is arranged on the main loop between the motor and the current transformer in a parallel connection mode with the main loop, and an access point of the contactor on the main loop is positioned between the soft starter and the current transformer; the contactor and the soft starter are both connected with the PLC; the contactor is connected with a low-speed winding wiring terminal of the motor, and the soft starter is connected with a high-speed winding wiring terminal of the motor.
Furthermore, a circuit breaker, or an incoming circuit breaker or a disconnecting switch is arranged between the incoming line end and the current transformer.
Further, the respective current signal ends of the current transformers are connected with the current transformer port of the PLC; the starting signal relay KA1 is connected to the RUN starting port of the soft starter, and the output port of the high-speed starting relay of the PLC is connected with the starting signal relay KA 1; the soft starter communication port is connected with the communication port of the PLC controller.
Furthermore, the output ports of the low-speed contactors of the PLC controller are respectively connected with the contactors.
Further, when the motor windings are at least 3 groups, at least one contactor is arranged as a main contactor 1KM1, and the main contactor 1KM1 is connected with a low-speed winding motor wiring terminal; meanwhile, auxiliary contactors with the same number as the high-speed windings are arranged in parallel on a main loop between the motor and the soft starter, and the auxiliary contactors are connected with high-speed winding motor wiring terminals except the low-speed windings in a one-to-one correspondence mode.
Further, when the motor windings are 3 groups, a contactor is arranged to be connected with a wiring terminal of the low-speed winding motor; 2 auxiliary contactors are arranged in parallel on a main loop between the motor and the soft starter and connected with a binding post of the high-speed winding motor.
Compared with the prior art, the utility model discloses following beneficial effect has:
1. the system uses the soft starter, and the soft starter body has more comprehensive and safer protection functions (over/under voltage protection, reverse phase protection, three-phase current unbalance protection, input/output open phase and the like) for the motor. The system uses the contactor, and the contactor directly starts the motor with lower cost and simple structure. The main loop is provided with a soft starter, the soft starter drives a high-speed winding, a contactor drives a low-speed winding, the soft starter and the contactor are interlocked to share the running and starting of the motor together, the frequent starting of the motor can be met, and the service life of a driving system is prolonged.
2. The parameters of a soft starter and a contactor configured in a main loop are respectively matched with the windings of the double-speed motor, the high-current soft starter drives the windings of the high-speed motor, the low-current contactor drives the windings of the low-speed motor, and the parameters correspond to the high-speed motor and the low-speed motor, so that the protection is safer, and the performance is better;
3. the soft starter is used for driving a high-speed motor winding, the current is smooth in the starting process, the starting current peak value can be adjusted, and no secondary impact exists;
4. the contactor is used for driving the low-speed motor winding, so that the cost is low and the structure is simple;
5. the utility model discloses a high-speed low-speed motor that cuts need not stop, and interval a little time just can directly cut the low-speed start (or cut the low-speed at a high speed), and interval time can not arouse central air conditioning temperature to change, and customer experience is good, and the soft scheme that plays of tradition list, and the soft starter closes the back and must stop the heat dissipation rear and can start in succession, and is not good to user experience.
6. Traditional single soft start drive double speed motor, general market soft starter one hour start-up number of times 30 times, the utility model discloses high-speed soft start low-speed directly starts, and the low-speed that can realize 30 times of the motor per hour is fast cuts high-speed, and 30 times high-speed is fast cuts low-speed, and traditional soft start mode can only provide 15 times low-speed and cut high-speed, 15 times high-speed low-speed of cutting, the utility model discloses better accord with the on-the-spot speed governing requirement.
Drawings
Fig. 1 is a circuit structure diagram of a main loop of a two-speed motor driving system based on soft starter driving.
Fig. 2 is a circuit structure diagram of a main loop of a multi-speed motor driving system based on soft starter driving.
Fig. 3 is a circuit structure diagram of a main loop of a three-speed motor driving system based on a single soft starter and a contactor.
Fig. 4 is a diagram of another embodiment of a two-speed motor drive system primary circuit configuration for driving a two-speed motor based on a single soft starter + contactor.
Detailed Description
Example 1:
as shown in the main circuit structure diagram of the soft starter drive-based two-speed motor drive system in fig. 1. In fig. 1, in the motor 1 of the fixed-frequency two-speed compressor, a1, B2 and C3 are high-speed winding motor terminals, and a4, B5 and C6 are low-speed winding motor terminals. The main circuit of the motor winding 1 of the fixed-frequency double-speed compressor is connected to the inlet ends L1, L2, L3 and PE, and an SS soft starter 2, a current transformer CT1, a CT2 and a CT3 are sequentially arranged between the inlet end and the motor 1; a QF1 incoming line breaker or a disconnecting switch 4 is arranged before the incoming line end is connected into the main loop; the current signal ends of the current transformers CT1, CT2 and CT3 are connected with current transformer ports U +/U-, V +/V-and W +/W-of the PLC controller and used for feeding current signals back to the PLC; the power supply port L/N port of the PLC is respectively connected with the wire inlet ends L1, L2, L3 and N; the output port AO/A1 of the low-speed contactor of the PLC controller is respectively connected with a KM1 contactor 3 for controlling the low-speed winding;
an MODBUS communication port of the soft starter 2 is connected with an MODBUS communication port 485A/485B/PE of the PLC, and the PLC can read and write data through the communication port; the RUN port of the soft starter 2 is a starting signal port, the starting signal port is started when the soft starter is closed and stopped when the soft starter is disconnected, the starting signal relay KA1 is connected to the RUN starting port of the soft starter 2, and the output port RUN/COM of the high-speed starting relay of the PLC controller is connected with the starting signal relay KA 1.
A KM1 contactor 3 is connected in parallel between a main loop between the soft starter 2 and current transformers CT1, CT2 and CT3 and the motor 1, and the KM1 contactor 3 is connected with low-speed winding motor terminals A4, B5 and C6 of the motor 1 and used for driving a low-speed winding. The SS soft starter 2 is connected with high-speed winding motor terminals A1, B2 and C3 of the motor 1 for driving a high-speed winding.
The ground terminal of the motor 1 is connected to the ground terminal PE of the inlet terminal.
In this embodiment, the working principle of the motor driver is as follows:
the motor starting mode is soft starting, the starting mode is a slope current mode, the peak value of the starting current of the motor is limited, the starting voltage is adjusted, the current rises smoothly to enable the rotating speed of the motor to reach the rated rotating speed, the motor starting is completed, a high-speed winding A1, B2 and C3 of a motor winding 1 corresponds to a high-current Soft Starter (SS), the protection parameters are protected according to the high-speed current, the starting current is also limited according to the high-speed current, and the starting current is guaranteed to be smooth; the low-speed windings A4, B5 and C6 of the motor winding 1 correspond to a low-speed contactor KM1, and protection parameters are protected according to low-speed current.
The high-speed and low-speed switching mode of the motor is as follows: when the high speed is switched to the low speed, the SS soft starter 2 stops outputting, the low speed KM1 contactor 3 is started after 1 second, and the motor is started to enable the motor to operate at the low speed; when the low speed is switched to the high speed, the low speed contactor KM1 stops outputting, and the high speed SS soft starter 2 is started to start the motor after 1 second, so that the motor runs at the high speed.
The soft starter and the contactor share the starting and running of one motor together, the contactor stops when the soft starter runs, and the contactor runs when the soft starter stops, so that the requirement of frequent starting can be met, and the service life of a device is prolonged;
in all starting and running processes, current signals are fed back to the PLC by the current transformers CT1, CT2 and CT3, and the controller protects the starting and running conditions of the motor according to the current values.
The controller receives current feedback of current transformers CT1, CT2 and CT3 and performs overload protection on the current of the motor; the controller receives the voltage signal to protect the unit voltage and the phase sequence.
The controller receives the auxiliary contact signal of the KM1 contactor 3, and whether the contactor is attracted and released for incoming line protection is determined: starting to judge the state of an auxiliary contact of the contactor after a contactor closing command, and if the auxiliary contact is in an open circuit state, determining that the contactor does not pick up a fault; and starting to judge the state of the auxiliary contact of the contactor after the opening command of the contactor, and if the auxiliary contact is in a closed state, determining that the contactor does not release faults.
The soft starter and the contactor of the system are directly connected to the motor wiring terminal, the six wiring terminals of the double-speed motor are adopted, the soft starter and the contactor are only connected with 3 groups of power cables in a butt joint mode with the motor respectively, and wiring is simple.
Example 2:
fig. 2 is a circuit configuration diagram of a main loop of a multi-speed motor driving system based on soft starter driving, which is expanded based on embodiment 1.
The constant-frequency multi-speed compressor is different from the embodiment 1 in that a motor 1 of the constant-frequency multi-speed compressor is provided with a plurality of windings (the number of windings corresponds to multi-speed), motor windings A1, B2, C3 ~ AM, B (M +1) and C (M +2) are high-speed windings (M is a natural number), and the like, the rest windings A (M +3), B (M +4) and C (M +5) are low-speed windings (N is a natural number and M is less than N), two or more low-speed starting contactors (KM 3 KM 737M) are correspondingly connected in parallel between a main loop between AN SS soft starter 2 and current transformers CT1, CT2 and CT3 and the motor 1, auxiliary contactors (2KM1 ~ KM 2M) with the same number as the high-speed windings are arranged in parallel between the main loop between the motor 1 and the soft starter 2 and the motor 1, the high-speed starting contactors (KM) and the auxiliary contactors KM 2KM1 ~ KM 2M) are connected in parallel, the main loop between the motor 1 and the soft starter 2, the high-speed windings (KM) are connected with the windings (KM 1 ~, the windings corresponding to be connected with high-speed windings (A +3) and the high-speed windings (KM) windings (M +3) windings (M) which are connected with terminals except for driving the high-speed windings (A +3) windings (KM) and the high-speed windings (M +3) which are connected with the high-speed windings (A, the high-speed windings (KM) windings (M + conductors (KM) and the high-speed windings (C + conductors (C +3) which are connected with the high-.
The multi-speed motor driver based on soft starter driving in this embodiment operates as follows:
before the motor is started, the controller PLC controls a low-speed starting contactor 3 (one KMM in KM1 ~) corresponding to a winding needing to be started to attract first, and then controls the SS soft starter 2 to start.
When switching the low speed at a high speed, the controller stops the SS soft starter 2, releases the high-speed auxiliary contactor 2KMM corresponding to the winding, then starts the low-speed contactor 1KMN, and stops the low-speed winding from starting to run at a high-speed winding of the motor.
When the high speed is switched at the low speed, the controller stops the low speed starting contactor 3 (KM 1), then starts the high speed auxiliary speed contactor 3 (KMM), and then starts the high speed SS soft starter 2; the low speed winding of the motor is stopped and the high speed winding is started to run.
Matching of a multi-speed (speed greater than 2) motor with a soft starter: the current of the high-speed soft starter is the highest-speed winding with the rotating speed A, the middle rotating speed B (B is less than or equal to A/3) winding is determined together, and the windings are correspondingly as follows: the windings with the rotating speed of A being more than or equal to that of B are all driven by high-speed soft start, and the windings with the rotating speed of B being less than or equal to that of A are all driven by low-speed contactors.
Example 3:
the embodiment 3 shown in figure 3 is formed by further improving the embodiment 1. This embodiment differs from embodiment 1 in that a three-speed motor drive system is formed based on a single soft starter (high-speed soft starter SS) and three contactors (1 KM1,2KM 1,2KM 2). Wherein the reference numerals are as follows: SS-high-speed soft starter, QF 1-breaker, PLC-controller, CT1, CT2 and CT3 current transformer.
Among the three contactors, a low-speed starting contactor 1KM1 is connected with a main loop in parallel, and the parallel connection point is arranged among current transformers CT1, CT2 and CT3 of the main loop and a high-speed soft starter SS; 2KM1,2KM2 are high speed auxiliary contactors, 2KM1 is arranged on the main loop between the motor 1 and the high speed soft starter SS, and 2KM2 is connected in parallel with 2KM 1.
A motor 1 of the constant-frequency multi-speed compressor is provided with three windings, motor terminals A1, B2 and C3 are high-speed windings, A4, B5 and C6 are medium-speed windings, A7, B8 and C9 are low-speed windings, a low-speed starting contactor 1KM1 is connected with the low-speed windings A7, B8 and C9, a high-speed auxiliary contactor 2KM1 is connected with the high-speed winding motor terminals A1, B2 and C3, and a high-speed auxiliary contactor 2KM2 is connected with the medium-speed windings A4, B5 and C6.
And other ports of the PLC are connected in a constant mode. Such as: an RUN starting port of the high-speed soft starter SS passes through an output port RUN/COM of a high-speed starting relay of a starting signal relay KA1 PLC controller; the three contactors (1 KM1,2KM 1 and 2KM 2) are respectively connected with the output ports AO, A3 and A5 of the low-speed contactor of the PLC controller.
Therefore, the motor 1 can be started in three speed states by switching the three contactors (1 KM1,2KM 1 and 2KM 2) and the high-speed soft starter SS.
Example 4
As shown in fig. 4, yet another embodiment is a block diagram of a primary circuit of a two-speed motor drive system based on a single softstarter + contactor drive two-speed motor.
The difference on the basis of fig. 1 is that: a single soft starter + contactor driving double-speed motor driving system is formed by using an isolating switch QS to replace an incoming line breaker QF1 or an isolating switch. This greatly reduces the cost of the drive system compared to embodiment 1.
Other not illustrated embodiments and modifications also include the following:
two incoming line breakers QF1, a single soft starter and a contactor are used for forming a double-speed motor driving system; and a two-speed motor drive system is formed by using two incoming line breakers QF1, a reconfiguration disconnector QS, and a single soft starter + contactor. This simplified structure leads to a significant reduction in the cost of the drive system relative to embodiment 1.
By the above-mentioned embodiment that has illustrated and not illustrated can obtain, the utility model discloses a major loop core lies in using "single soft starter + the many speed motors of contactor drive" to constitute actuating system, and other subsidiary configurations are not limited to above form, and the scheme that all uses single soft starter + the many speed motors of contactor drive actuating system is in the utility model discloses a protection scope.
Compared with the prior art, the utility model discloses there is following beneficial effect:
1. the system uses the soft starter, and the soft starter body has more comprehensive and safer protection functions (over/under voltage protection, reverse phase protection, three-phase current unbalance protection, input/output open phase and the like) for the motor. The system uses the contactor, and the contactor directly starts the motor with lower cost and simple structure. The main loop is provided with a soft starter, the soft starter drives a high-speed winding, a contactor drives a low-speed winding, the soft starter and the contactor are interlocked to share the running and starting of the motor together, the frequent starting of the motor can be met, and the service life of a driving system is prolonged.
2. The parameters of a soft starter and a contactor configured in a main loop are respectively matched with the windings of the double-speed motor, the high-current soft starter drives the windings of the high-speed motor, the low-current contactor drives the windings of the low-speed motor, and the parameters correspond to the high-speed motor and the low-speed motor, so that the protection is safer, and the performance is better;
3. as in embodiments 1,2 and 3, the soft starter is used for driving a high-speed motor winding, the current is smooth in the starting process, the starting current peak value can be adjusted, and no secondary impact exists;
4. the contactor is used for driving the low-speed motor winding, so that the cost is low and the structure is simple;
5. the utility model discloses a high-speed low-speed motor that cuts need not stop, interval a little time just can directly cut the low-speed start (or cut the low-speed at a high speed) like 1 second, and 1 second interval time can not arouse central air conditioning temperature to change, and customer experience is good, and the scheme is played in the tradition list is soft, and the soft starter closes the back and must stop the heat dissipation rear and can start in succession, and is not good to user experience. Particularly, the effect of the double-speed and the three-speed is particularly obvious.
6. Traditional single soft start drive double speed motor, general market soft starter one hour start-up number of times 30 times, the utility model discloses high-speed soft start low-speed directly starts, and the low-speed that can realize 30 times of the motor per hour is fast cuts high-speed, and 30 times high-speed is fast cuts low-speed, and traditional soft start mode can only provide 15 times low-speed and cut high-speed, 15 times high-speed low-speed of cutting, the utility model discloses better accord with the on-the-spot speed governing requirement. Particularly, the effect of the double-speed and the three-speed is particularly obvious.
Claims (6)
1. A motor driving system for a central air conditioner is characterized in that: the motor at least comprises 2 groups of windings, a current transformer and a soft starter are sequentially arranged on a main loop from a line inlet end to the motor, at least one contactor is arranged on the main loop between the motor and the current transformer in a parallel connection mode with the main loop, and an access point of the contactor on the main loop is positioned between the soft starter and the current transformer; the contactor and the soft starter are both connected with the PLC; the contactor is connected with a low-speed winding wiring terminal of the motor, and the soft starter is connected with a high-speed winding wiring terminal of the motor.
2. The motor drive system for a central air conditioner according to claim 1, characterized in that: a circuit breaker, or an incoming line circuit breaker or an isolating switch is arranged between the incoming line end and the current transformer.
3. The motor drive system for a central air conditioner according to claim 1, characterized in that: the current signal ends of the current transformers are connected with the current transformer port of the PLC; the starting signal relay KA1 is connected to the RUN starting port of the soft starter, and the output port of the high-speed starting relay of the PLC is connected with the starting signal relay KA 1; the soft starter communication port is connected with the communication port of the PLC controller.
4. The motor drive system for a central air conditioner according to claim 1, characterized in that: and the output ports of the low-speed contactors of the PLC controller are respectively connected with the contactors.
5. The motor drive system for a central air conditioner according to claim 1, characterized in that: when the motor windings are at least 3 groups, at least one contactor is arranged as a main contactor 1KM1, and the main contactor 1KM1 is connected with a low-speed winding motor wiring terminal with the lowest speed; meanwhile, auxiliary contactors with the same number as the high-speed windings are arranged in parallel on a main loop between the motor and the soft starter, and the auxiliary contactors are connected with high-speed winding motor wiring terminals except the low-speed windings in a one-to-one correspondence mode.
6. The motor drive system for a central air conditioner according to claim 1, characterized in that: when the motor windings are 3 groups, a contactor is arranged to be connected with a wiring terminal of the low-speed winding motor; 2 auxiliary contactors are arranged in parallel on a main loop between the motor and the soft starter and connected with a binding post of the high-speed winding motor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201920647736.6U CN209963973U (en) | 2019-05-07 | 2019-05-07 | Motor driving system for central air conditioner |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201920647736.6U CN209963973U (en) | 2019-05-07 | 2019-05-07 | Motor driving system for central air conditioner |
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| CN209963973U true CN209963973U (en) | 2020-01-17 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113501313A (en) * | 2021-07-13 | 2021-10-15 | 徐州徐工挖掘机械有限公司 | Electric material grabbing machine and walking circuit thereof |
| WO2024050083A1 (en) * | 2022-09-02 | 2024-03-07 | Copeland Lp | Compressor voltage protection module enabling based on soft starter detection |
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2019
- 2019-05-07 CN CN201920647736.6U patent/CN209963973U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113501313A (en) * | 2021-07-13 | 2021-10-15 | 徐州徐工挖掘机械有限公司 | Electric material grabbing machine and walking circuit thereof |
| WO2024050083A1 (en) * | 2022-09-02 | 2024-03-07 | Copeland Lp | Compressor voltage protection module enabling based on soft starter detection |
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