Air conditioner soft start control system

Abstract

The utility model provides a kind of air conditioner soft-start control system, air conditioner starting interface, current detection module, power control unit, bypass unit, temperature detection module, through bypass unit through soft-start, start smooth, reliable operation, when magnetic retainer B is attracted, the trigger signal of thyristor SCR3, thyristor SCR4 is removed, thyristor SCR3, thyristor SCR4 stop conducting, compared with traditional contactor in entire bypass conduction period needs to continue coil power supply, can realize significant energy saving, system long-term operation total energy consumption is greatly reduced, while avoiding coil continuous heating problem, it is favorable to improve system overall reliability and reduce heat dissipation demand;While setting phase-loss protection module, distinguish zero line loss and fire line loss etc. Fault type, accurate trigger protection and store fault code, diagnosis is convenient.

Description

Technical Field

[0001] This utility model relates to the field of air conditioning control technology, and more specifically, to an air conditioning soft-start control system. Background Technology

[0002] Air conditioning equipment generates an inrush current of 5-8 times its rated current upon startup, causing serious damage to power grid stability, compressor lifespan, and electrical components such as contactors and fuses. Traditional solutions mainly fall into two categories:

[0003] (1) Pure contactor starting scheme: The main circuit is directly connected through mechanical contacts. The structure is simple but cannot suppress surge current. Frequent start and stop can easily lead to contact sticking or burning.

[0004] (2) The thyristor soft-start scheme (application publication number CN117477987A-A soft-start circuit and device for a three-phase AC motor) discloses that it gradually increases the voltage by using phase control, which can reduce the inrush current, but still has the following defects:

[0005] ① The contactor KM bypass thyristor is used, which requires continuous power to maintain engagement, resulting in high energy consumption;

[0006] ② Crude fault diagnosis: Phase loss protection relies on the threshold judgment of current sampling comparators (such as U4A / U4B), which cannot distinguish between neutral wire loss and live wire loss, and has no fault code storage function.

[0007] Therefore, there is an urgent need for an air conditioning soft-start system with low energy consumption and multi-dimensional fault protection to simultaneously solve the problems of energy efficiency, safety and reliability. Utility Model Content

[0008] The purpose of this invention is to propose an air conditioning soft-start system with low energy consumption and multi-dimensional fault protection.

[0009] An air conditioning soft-start control system, characterized in that it includes:

[0010] The air conditioner start interface is used to receive the output signal from the microcontroller and start the air conditioning equipment.

[0011] The control module includes a microcontroller, which is used to generate trigger pulse signals and process feedback signals;

[0012] The current detection module includes a comparator amplifier circuit connected to the air conditioner start interface, which collects the start current, circuit temperature and voltage signals in real time and provides them to the microcontroller.

[0013] The power control unit includes two thyristors, SCR3 and SCR4, connected in reverse parallel, with their gates connected to the output of the microcontroller, and a contactor KM connected in series in the main circuit.

[0014] The bypass unit includes a magnetic latch B, whose contacts are connected in parallel across the two ends of thyristors SCR3 and SCR4. The control coil is connected to a microcontroller. When the magnetic latch B is engaged, the trigger signals of thyristors SCR3 and SCR4 are removed, and thyristors SCR3 and SCR4 stop conducting. At this time, the magnetic latch B is activated to bypass the circuit.

[0015] The temperature detection module includes a thermistor mounted on the heat dissipation surface of thyristor SCR3 and thyristor SCR4, and outputs a temperature signal to the microcontroller.

[0016] The microcontroller is configured to reduce the thyristor conduction angle when the temperature exceeds a threshold and to turn off the trigger signal when the temperature continues to exceed the threshold.

[0017] In some embodiments, an energy storage and filtering unit is provided between the microcontroller and the air conditioner start interface, including a 200-240uF electrolytic capacitor C1, a series fuse F2, and a normally open manual trigger switch JK2. The 200-240uF electrolytic capacitor C1 is connected in parallel to the power supply circuit to stabilize the start voltage. The series fuse F2 provides overcurrent protection, and the normally open manual trigger switch JK2 enables the transmission of the start signal.

[0018] In some embodiments, a 5-10Ω NTC1 thermistor is connected in series between the trigger switch JK2 and the air conditioner start interface to suppress surge current ≥100A.

[0019] In some embodiments, diode D4 is connected in reverse parallel across the two ends of thyristor SCR3, and diode D5 is connected in reverse parallel across the two ends of thyristor SCR4 to form an absorption circuit with a reverse electromotive force of ≥50V when turned off.

[0020] In some embodiments, an RC snubber circuit is connected in parallel across the contacts of the magnetic latch B, comprising a 0.1uF capacitor CX3 and a 10Ω resistor R23 connected in series, for absorbing voltage spikes of ≥200V when the contacts are broken.

[0021] In some implementations, a phase loss protection module is also included to detect abnormal voltages in the live wire and neutral wire and trigger shutdown. The phase loss protection module includes a live wire voltage sampling circuit and a neutral wire voltage sampling circuit. The live wire voltage sampling circuit and the neutral wire voltage sampling circuit are connected to a microcontroller. The microcontroller compares the voltage difference between the two circuits. If the voltage difference exceeds the limit continuously, the microcontroller shuts down thyristor SCR3 and thyristor SCR4. The microcontroller also distinguishes the fault type based on the voltage deviation range and stores the corresponding fault code.

[0022] Furthermore, the fault types include neutral wire missing type and live wire missing type. Neutral wire missing type is characterized by a voltage difference > 100V, and live wire missing type is characterized by a voltage difference < 5V and zero current.

[0023] In some embodiments, an emergency power supply module is also included to maintain the operation of the ventilation motor when the main power supply fails; the emergency power supply module includes an energy storage unit connected in parallel to the contacts of the magnetic latch B; when the main power supply fails and the temperature is safe, the magnetic latch B is controlled to release its contacts, and the energy storage unit maintains the operation of the motor.

[0024] In some implementations, the microcontroller has a pre-set startup state machine logic that is executed sequentially: in the initial stage, a fixed 30° conduction angle is maintained for 200ms; in the ramp stage, the conduction angle is increased to 150° at a rate of 2° / ms; in the voltage regulation stage, the conduction angle is dynamically adjusted to make the voltage fluctuation ≤ ±5% of the rated value; when the temperature exceeds the limit or the current change is > 50%, it returns to the previous stage.

[0025] The beneficial effects of this utility model are as follows: This utility model proposes an air conditioner soft-start control system, which includes an air conditioner start interface, a current detection module, a power control unit, a bypass unit, and a temperature detection module. Through the bypass unit, soft starting is achieved, resulting in smooth start-up and reliable operation. When the magnetic latch B is engaged, the trigger signals of thyristors SCR3 and SCR4 are removed, and thyristors SCR3 and SCR4 stop conducting. Compared with traditional contactors that require continuous coil power supply during the entire bypass conduction period, significant energy savings can be achieved, and the total energy consumption of the system during long-term operation is greatly reduced. At the same time, the problem of continuous coil heating is avoided, which is conducive to improving the overall reliability of the system and reducing heat dissipation requirements. In addition, a phase loss protection module is set up to distinguish between fault types such as neutral wire loss and live wire loss, accurately trigger protection and store fault codes, making diagnosis convenient. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the module connection structure of the air conditioning soft-start control system of this application.

[0027] Figure 2 This is a schematic diagram of the circuit structure of the air conditioning soft-start control system of this application.

[0028] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation

[0029] The following embodiments are described to aid in understanding this application. These embodiments are not, and should not be, construed in any way as limiting the scope of protection of this application.

[0030] In the following description, those skilled in the art will recognize that throughout this discussion, components may be described as individual functional units (which may include subunits), but those skilled in the art will recognize that various components or portions thereof may be divided into individual components or may be integrated together (including integrated within a single system or component).

[0031] Furthermore, the connection between components or systems is not intended to be limited to a direct connection; on the contrary, data between these components may be modified, reformatted, or otherwise altered by intermediate components. Additionally, other or fewer connections may be used. It should also be noted that the terms "connection," "link," or "input" should be understood to include direct connections, indirect connections via one or more intermediate devices, and wireless connections. Example 1:

[0032] like Figure 1 The diagram shown is a schematic of the module connection structure of the air conditioning soft-start control system of this application; as shown... Figure 2 The diagram shown is a schematic diagram of the circuit structure of the air conditioning soft-start control system of this application.

[0033] An air conditioning soft-start control system, characterized in that it includes:

[0034] The air conditioner start interface is used to receive the output signal from the microcontroller and start the air conditioning equipment.

[0035] The control module includes a microcontroller, which is used to generate trigger pulse signals and process feedback signals;

[0036] The current detection module includes a comparator amplifier circuit connected to the air conditioner start interface, which collects the start current, circuit temperature and voltage signals in real time and provides them to the microcontroller.

[0037] The power control unit includes two thyristors, SCR3 and SCR4, connected in reverse parallel, with their gates connected to the output of the microcontroller, and a contactor KM connected in series in the main circuit.

[0038] The bypass unit includes a magnetic latch B, whose contacts are connected in parallel across the two ends of thyristors SCR3 and SCR4. The control coil is connected to a microcontroller. When the magnetic latch B is engaged, the trigger signals of thyristors SCR3 and SCR4 are removed, and thyristors SCR3 and SCR4 stop conducting. At this time, the magnetic latch B is activated to bypass the circuit.

[0039] The temperature detection module includes a thermistor mounted on the heat dissipation surface of thyristor SCR3 and thyristor SCR4, and outputs a temperature signal to the microcontroller.

[0040] The microcontroller is configured to reduce the thyristor conduction angle when the temperature exceeds a threshold and to turn off the trigger signal when the temperature continues to exceed the threshold.

[0041] An energy storage and filtering unit is provided between the microcontroller and the air conditioner start interface, including a 200-240uF electrolytic capacitor C1, a series fuse F2, and a normally open manual trigger switch JK2. The 200-240uF electrolytic capacitor C1 is connected in parallel to the power supply circuit to stabilize the start voltage. The series fuse F2 provides overcurrent protection, and the normally open manual trigger switch JK2 enables the transmission of the start signal.

[0042] A 5-10Ω NTC1 thermistor is connected in series between the trigger switch JK2 and the air conditioner start interface to suppress surge current ≥100A.

[0043] The thyristor SCR3 is connected in reverse parallel with diode D4, and the thyristor SCR4 is connected in reverse parallel with diode D5, forming an absorption circuit with a reverse electromotive force of ≥50V when turned off.

[0044] The magnetic latch B has an RC snubber circuit connected in parallel across its contacts, which includes a 0.1uF capacitor CX3 and a 10Ω resistor R23 connected in series to absorb voltage spikes of ≥200V when the contacts are broken.

[0045] It also includes a phase loss protection module, which is used to detect abnormal voltages in the live wire and neutral wire and trigger shutdown. The phase loss protection module includes a live wire voltage sampling circuit and a neutral wire voltage sampling circuit. The live wire voltage sampling circuit and the neutral wire voltage sampling circuit are connected to a microcontroller. The microcontroller compares the voltage difference between the two circuits. When the voltage difference exceeds the limit, it shuts down thyristor SCR3 and thyristor SCR4. The microcontroller also distinguishes the fault type based on the voltage deviation range and stores the corresponding fault code.

[0046] The fault types include neutral wire missing type and live wire missing type. Neutral wire missing type is when the voltage difference is >100V, and live wire missing type is when the voltage difference is <5V and the current is zero.

[0047] It also includes an emergency power supply module, which is used to maintain the operation of the ventilation motor when the main power supply fails; the emergency power supply module includes an energy storage unit connected in parallel to the contacts of the magnetic latch B; when the main power supply fails and the temperature is safe, the magnetic latch B is controlled to release the contacts, and the energy storage unit maintains the operation of the motor.

[0048] The microcontroller has a pre-set startup state machine logic that is executed in sequence: in the initial stage, the conduction angle is fixed at 30° and maintained for 200ms; in the ramp stage, the conduction angle is increased to 150° at a rate of 2° / ms; in the voltage regulation stage, the conduction angle is dynamically adjusted to make the voltage fluctuation ≤ ±5% of the rated value; when the temperature exceeds the limit or the current change is > 50%, it returns to the previous stage.

[0049] The beneficial effects of this utility model are as follows: This utility model proposes an air conditioner soft-start control system, which includes an air conditioner start interface, a current detection module, a power control unit, a bypass unit, and a temperature detection module. Through the bypass unit, soft starting is achieved, resulting in smooth start-up and reliable operation. When the magnetic latch B is engaged, the trigger signals of thyristors SCR3 and SCR4 are removed, and thyristors SCR3 and SCR4 stop conducting. Compared with traditional contactors that require continuous coil power supply during the entire bypass conduction period, significant energy savings can be achieved, and the total energy consumption of the system during long-term operation is greatly reduced. At the same time, the problem of continuous coil heating is avoided, which is conducive to improving the overall reliability of the system and reducing heat dissipation requirements. In addition, a phase loss protection module is set up to distinguish between fault types such as neutral wire loss and live wire loss, accurately trigger protection and store fault codes, making diagnosis convenient.

[0050] Although this application discloses several aspects and embodiments, other aspects and embodiments will be obvious to those skilled in the art. Various modifications and improvements can be made without departing from the concept of this application, and all such modifications and improvements fall within the scope of protection of this application. The various aspects and embodiments disclosed in this application are for illustrative purposes only and are not intended to limit this application. The actual scope of protection of this application is determined by the claims.

Claims

1. An air conditioning soft-start control system, characterized in that, include: The air conditioner start interface is used to receive signals from the microcontroller and start the air conditioning equipment. The control module includes a microcontroller, which is used to generate trigger pulse signals and process feedback signals; The current detection module includes a comparator amplifier circuit connected to the air conditioner start interface, which collects the start current, circuit temperature and voltage signals in real time and provides them to the microcontroller. The power control unit includes two thyristors, SCR3 and SCR4, connected in reverse parallel, with their gates connected to the output of the microcontroller, and a contactor KM connected in series in the main circuit. The bypass unit includes a magnetic latch B, whose contacts are connected in parallel across the two ends of thyristors SCR3 and SCR4. The control coil is connected to a microcontroller. When the magnetic latch B is engaged, the trigger signals of thyristors SCR3 and SCR4 are removed, and thyristors SCR3 and SCR4 stop conducting. At this time, the magnetic latch B is activated to bypass the circuit. The temperature detection module includes a thermistor mounted on the heat dissipation surface of thyristors SCR3 and SCR4, and outputs a temperature signal to a microcontroller; wherein the microcontroller is configured to reduce the conduction angle of the thyristors when the temperature exceeds a threshold, and to turn off the trigger signal when the temperature continues to exceed the threshold.

2. The air conditioning soft-start control system as described in claim 1, characterized in that: An energy storage and filtering unit is provided between the microcontroller and the air conditioner start interface, including a 200-240uF electrolytic capacitor C1, a series fuse F2, and a normally open manual trigger switch JK2. The 200-240uF electrolytic capacitor C1 is connected in parallel to the power supply circuit to stabilize the start voltage. The series fuse F2 provides overcurrent protection, and the normally open manual trigger switch JK2 enables the transmission of the start signal.

3. The air conditioning soft-start control system as described in claim 2, characterized in that: A 5-10Ω NTC1 thermistor is connected in series between the trigger switch JK2 and the air conditioner start interface to suppress surge current ≥100A.

4. The air conditioning soft-start control system as described in claim 1, characterized in that: The thyristor SCR3 is connected in reverse parallel with diode D4, and the thyristor SCR4 is connected in reverse parallel with diode D5, forming an absorption circuit with a reverse electromotive force of ≥50V when turned off.

5. The air conditioning soft-start control system as described in claim 1, characterized in that: The magnetic latch B has an RC snubber circuit connected in parallel across its contacts, which includes a 0.1uF capacitor CX3 and a 10Ω resistor R23 connected in series to absorb voltage spikes of ≥200V when the contacts are broken.

6. The air conditioning soft-start control system as described in claim 1, characterized in that: It also includes a phase loss protection module, which is used to detect abnormal voltages in the live wire and neutral wire and trigger shutdown. The phase loss protection module includes a live wire voltage sampling circuit and a neutral wire voltage sampling circuit. The live wire voltage sampling circuit and the neutral wire voltage sampling circuit are connected to a microcontroller. The microcontroller compares the voltage difference between the two circuits. When the voltage difference exceeds the limit, it shuts down thyristor SCR3 and thyristor SCR4. The microcontroller also distinguishes the fault type based on the voltage deviation range and stores the corresponding fault code.

7. The air conditioning soft-start control system as described in claim 1, characterized in that: The fault types include neutral wire missing type and live wire missing type. Neutral wire missing type is when the voltage difference is >100V, and live wire missing type is when the voltage difference is <5V and the current is zero.

8. The air conditioning soft-start control system as described in claim 1, characterized in that: It also includes an emergency power supply module, which is used to maintain the operation of the ventilation motor when the main power supply fails; the emergency power supply module includes an energy storage unit connected in parallel to the contacts of the magnetic latch B; when the main power supply fails and the temperature is safe, the magnetic latch B is controlled to release the contacts, and the energy storage unit maintains the operation of the motor.

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