CN107666266A - Inverter air conditioner control method, control device and storage medium - Google Patents

Abstract

The invention provides a control method, a control device and a storage medium of a variable frequency air conditioner, which are characterized in that an alternating voltage value is detected in real time, when the alternating voltage value is lower than a first preset value, a controllable switch is controlled to be switched off to control direct current voltage to charge an electrolytic capacitor through a first resistor, and when the direct current voltage value is higher than a second preset value, the controllable switch is controlled to be switched on to control direct current voltage to finish charging the electrolytic capacitor through the first resistor, wherein the second preset value is larger than the first preset value. According to the control method of the variable frequency air conditioner, when the alternating voltage loaded from the outside has large fluctuation and is rapid, the switch is timely disconnected to be connected with the first resistor, so that the first resistor plays a role in limiting the charging current of the electrolytic capacitor E1, the phenomenon that the charging current of the electrolytic capacitor E1 is overlarge to damage components such as a rectifier when the controllable switch is controlled to be closed all the time in the prior art is avoided, and the reliability of the control circuit board of the variable frequency air conditioner is improved.

Description

Inverter air conditioner control method, control device and storage medium

technical field

The invention relates to the control field of frequency conversion air conditioners, in particular to a control method, a control device and a storage medium of frequency conversion air conditioners.

Background technique

The existing variable frequency air conditioner controllable circuit The power supply circuit in the outdoor unit control circuit mainly charges the electrolytic capacitor through the PTC resistance + relay switch mode. , to charge the electrolytic capacitor. After a period of time, the MCU controls the switch to close, and the charging control ends. When the power supply voltage is unstable and the voltage fluctuates rapidly, the switch is always closed at this time, so there is no resistance current limiting effect, and a large charging current will be generated. This has a large current impact on the rectifier bridge and other components, which may damage the rectifier bridge and other components, and affect the reliability of the control circuit board.

Contents of the invention

The main purpose of the present invention is to provide a control method, a control device and a storage medium for an inverter air conditioner. The device thus affects control circuit reliability issues.

In order to achieve the above object, the present invention provides a control method for an inverter air conditioner, the control method is applied to a control device for an inverter air conditioner, and the control device for an inverter air conditioner includes a first resistor, a controllable switch, a voltage detection circuit, a rectifier , an electrolytic capacitor, a load, and a controller, the first resistor is connected in series between one end of the input alternating current and an input end of the rectifier, the controllable switch is connected in parallel with the first resistor, and the rectifier is used for the The input AC power is rectified to output a DC voltage, the DC voltage supplies power to the load, the voltage detection circuit is used to detect the input AC voltage value of the inverter air conditioner control device, and the controller according to the input AC voltage The voltage value controls the action of the controllable switch to control the DC voltage to charge the electrolytic capacitor; the control method includes:

Using to detect the AC voltage value;

When the AC voltage value is lower than a first preset value, control the controllable switch to turn off, so as to control the DC voltage to charge the electrolytic capacitor through the first resistor;

When the AC voltage value is higher than a second preset value, the controllable switch is controlled to be closed to control the DC voltage to end charging the electrolytic capacitor through the first resistor, wherein the second preset value is greater than the first preset value.

Preferably, when the AC voltage value is lower than a first preset value, the step of controlling the controllable switch to turn off further includes:

control the load off.

Preferably, when the AC voltage value is higher than a second preset value, the step of controlling the controllable switch to be closed further includes:

When it is detected that the AC voltage value is higher than a second preset value and lasts for a preset time, the controllable switch is controlled to be closed.

Preferably, the value range of the preset time is 0.5-3S.

Preferably, when the input AC voltage is 220V, the value range of the first preset value is 75-85V, and the value range of the second preset value is 125-145V.

In order to achieve the above object, the present invention also provides a control device for an inverter air conditioner, including a first resistor, a controllable switch, a voltage detection circuit, a rectifier, an electrolytic capacitor, a load, and a controller, and the first resistor is connected in series with the input AC Between one end and an input end of a rectifier, the controllable switch is connected in parallel with the first resistor, and the rectifier is used to rectify the input AC power and output a DC voltage, and the DC voltage supplies power to the load , the voltage detection circuit is used to detect the input AC voltage value of the inverter air conditioner control device, and the controller controls the controllable switch action according to the input AC voltage value, so as to control the impact of the DC voltage on the The electrolytic capacitor is charged; where,

The controller includes a memory, and a control program of an inverter air conditioner that has been stored in the memory by a processor and can run on the processor. The control program of the inverter air conditioner realizes the described Steps of a method for controlling an inverter air conditioner.

Preferably, the voltage detection circuit includes a second resistor and a third resistor,

One end of the second resistor is connected to the AC L line, the other end of the second resistor is connected to one end of the third resistor, the other end of the third resistor is connected to the AC N line, and the second The connection point of the resistor and the third resistor is the output terminal of the voltage detection circuit.

Preferably, the load includes an intelligent power module and a compressor connected to the intelligent power module.

Preferably, the first resistor is a PTC resistor or a cement resistor.

In order to achieve the above object, the present invention also provides a computer-readable storage medium, the computer-readable storage medium stores a control program of an inverter air conditioner, and when the control program of the inverter air conditioner is executed by a processor, the described Steps of a method for controlling an inverter air conditioner.

The control method of the inverter air conditioner provided by the present invention detects the AC voltage value in real time, and when the AC voltage value is lower than the first preset value, the controllable switch is controlled to be turned off, so as to control the DC voltage to charge the electrolytic capacitor through the first resistor , and when the DC voltage value is higher than a second preset value, the controllable switch is controlled to close, so as to control the DC voltage to end charging the electrolytic capacitor through the first resistor, wherein the second preset value is greater than the first preset value. In the control method of the inverter air conditioner of the present invention, when the externally loaded AC voltage fluctuates rapidly, the switch is disconnected in time to connect to the first resistor, so that the first resistor plays a role of limiting the charging current of the electrolytic capacitor E1, thereby It avoids damage to components such as rectifiers due to excessive charging current of the electrolytic capacitor E1 when the controllable switch is always closed in the prior art, and improves the reliability of the control circuit board of the inverter air conditioner.

Description of drawings

1 is a schematic diagram of the circuit structure of the inverter air conditioner control device of the first embodiment of the inverter air conditioner control method of the present invention;

Fig. 2 is the concrete circuit structure schematic diagram of the inverter air conditioner control device of the present invention;

Fig. 3 is a schematic diagram of the functional modules of the inverter air conditioner controller of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

Referring to Fig. 1, Fig. 1 is a schematic diagram of the circuit structure based on the inverter air conditioner control device of the inverter air conditioner control method provided by the first embodiment of the present invention. as follows:

The inverter air conditioner control device includes a first resistor R1, a controllable switch K, a voltage detection circuit 10, a rectifier 20, an electrolytic capacitor E1, a load 40, and a controller 30. The first resistor R1 is connected in series with one end of the input alternating current and one end of the rectifier 20. Between the input terminals, the rectifier 20 has two input terminals, one of which can be connected to the live wire of the AC power supply through the first resistor R1, and the other input terminal of the rectifier 20 is connected to the neutral line of the AC power supply, and the controllable switch K and the first A resistor R1 is connected in parallel, the rectifier 20 is used to rectify the input AC power and output a DC voltage, the DC voltage supplies power to the load 40, the voltage detection circuit 10 is used to detect the input AC voltage value of the inverter air conditioner control device, the controller 30 according to the voltage The power supply voltage value detected by the current detection controls the action of the controllable switch K to control the DC voltage to charge the electrolytic capacitor E1; the control method includes:

Step S10, sampling and detecting the AC voltage value;

Step S20, when the AC voltage value is lower than the first preset value, control the controllable switch to turn off, so as to control the DC voltage to charge the electrolytic capacitor through the first resistor R1;

Step S30, when the AC voltage value is higher than the second preset value, control the controllable switch K to close, so as to control the DC voltage to finish charging the electrolytic capacitor E1 through the first resistor R1, wherein the second preset value is greater than the first preset value value.

The inverter air conditioner control device of this embodiment can be applied to the outdoor control circuit of the inverter air conditioner, and is used to provide power for outdoor loads. For example, the AC input power is rectified by the above-mentioned rectifier 20 and filtered by the electrolytic capacitor E1 to output the DC bus voltage. , for outdoor loads such as compressors, outdoor fan motors, etc. The capacity of E1 is relatively large. For example, for a 1 horsepower inverter air conditioner on-hook, its electrolytic capacitor E1 has a capacity of 800uF and a withstand voltage of 450V.

The voltage detection circuit 10 of this embodiment is arranged at the input end of the AC power supply, and is used to detect the AC voltage value of the AC power supply. Specifically, as a specific circuit structure of the voltage detection circuit 10, as shown in FIG. 1, the voltage detection circuit 10 includes a second resistor R2 and a third resistor R3, one end of the second resistor R2 is connected to the AC power line L, the other end of the second resistor R2 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the AC power N line, The connection point of the second resistor R2 and the third resistor R3 is the output terminal of the voltage detection circuit 10, and its output terminal is connected to the controller 30, that is, the voltage detection circuit uses a simple voltage dividing resistor to detect the AC voltage. The circuit 10 can also adopt other circuit forms such as detection by using an isolation transformer, which will not be repeated here.

In practical applications, the first resistor R1 of this embodiment may use a high-power PTC resistor or a cement resistor to reduce voltage and limit current.

When the control device of the inverter air conditioner in this embodiment is powered on in normal operation, the controller 30 controls the switch K to be turned off. At this time, the AC power charges the electrolytic capacitor E1 through the rectifier 20 through the PTC resistor R1. The characteristic of large temperature rise resistance, if the charging current is large, its resistance will increase, so it plays the role of limiting the charging current, and will not cause damage to the rectifier 20 when a large charging current passes through it. When the charging time passes through a preset time determined by an experiment, such as 10 seconds, it can be determined that the electrolytic capacitor E1 has been fully charged, that is, the DC bus voltage at both ends reaches a stable value. For example, for the input 220V AC voltage, the DC bus voltage reaches above 300V It can be considered that the charging has reached a stable value, and at this time, the controllable switch K is controlled to be turned on, and the AC input power directly supplies power to the subsequent circuit through the controllable switch K, so that the controller 30 can control the actions of related loads such as compressors, etc. .

In the actual working process, the input AC voltage will be unstable, especially when the voltage fluctuates rapidly, such as the voltage drops rapidly and returns to the normal continuous state. At this time, for the existing control, due to The controllable switch K has been controlled to charge the electrolytic capacitor E1, and the controllable switch K will continue to be controlled to close. Since the AC voltage on the input side drops below 80V when the voltage drop is large, the DC bus voltage at both ends of the electrolytic capacitor E1 is also It will drop seriously. If the AC input voltage continues to rise rapidly, a large instantaneous charging current will be formed on the electrolytic capacitor E1, which exceeds the withstand voltage of the rectifier 20. It will be damaged when it works like this for a long time. At the same time, the charging current will easily exceed the controllable voltage. The working current of the switch K is easy to cause its damage when working in this way for a long time.

Therefore, in the control method of the inverter air conditioner of this embodiment, the AC voltage value is detected in real time through the voltage detection circuit 10, that is, the instantaneous value of the AC voltage is detected. When the preset value is reached, the controllable switch K is turned off, and the first resistor R1 is connected at this time. When the AC input voltage rises rapidly, the AC input voltage passes through the first resistor R1 and the rectifier 20 to the electrolytic capacitor E1. Charging, due to the current limiting effect of the first resistor R1, will not cause damage to the rectifier 20 due to excessive charging current. If the voltage rises above the safe second preset value, it can be confirmed that the voltage across the electrolytic capacitor E1 has risen to a safe value at this time, so the charging current will be reduced to a safe value at this time, and the controllable switch K is closed at this time, that is Control the first resistor R1 to charge the electrolytic capacitor E1, and then the AC voltage can continue to charge the electrolytic capacitor through the controllable switch K, but at this time the charging current has dropped below the safe value, because according to the charging characteristics of the electrolytic capacitor, its charging The magnitude of the current rises exponentially. The current is large in the initial stage of charging, and the current will be greatly reduced in the later stage of charging. The closer the voltage value is to the stable value, the slower the current changes. Therefore, if it is detected that the voltage has risen above the safe value, then its The charging current is reduced to within the safe value, and by detecting that the AC voltage at the input terminal rises above the second preset value, it can be inferred that the voltage at both ends of the electrolytic capacitor E1 has risen above the safe value, and the large charging current will not cause the rectifier 20 damage. Specifically, when the input AC voltage is 220V, it is determined through experiments that the value range of the first preset value is 75-85V, such as 80V, and the range of the second preset value is 125-145V, such as 130V.

It is worth noting that what the voltage detection circuit 10 detects here is the voltage value on the AC side, not the DC bus voltage value at both ends of the electrolytic capacitor E1. It cannot reflect the rapid change of the AC input voltage value in real time. If the above-mentioned rapid fluctuation of the AC voltage occurs, the DC bus voltage value will change much more slowly. Therefore, the DC bus voltage value cannot monitor the change of the AC voltage in real time. If the action is not timely and accurate, the current limiting effect of the first resistor R1 on charging the electrolytic capacitor E1 cannot be realized.

Further, when the AC voltage rises above the safe second preset value, continue to detect the duration of the AC voltage rising to the safe second preset value, if it is higher than the second preset value and lasts for the preset time, Only when the controllable switch K is closed is controlled, it can be further confirmed that the AC voltage will not fluctuate rapidly and greatly. If the detection and control of the above duration are not added, when the voltage fluctuates rapidly, it may cause the controllable switch K to control. Switch back and forth quickly, which will reduce the working life of switch K. It is determined through experiments that the value range of the continuous preset time is 0.5-3S, for example, the value is 1S.

Further, when the AC voltage value is lower than the first preset value, while the controllable switch K is controlled to be disconnected, the relevant loads are also controlled to be shut down. Specifically, for inverter air conditioners, the compressors, fans and other high-current loads can be controlled to be shut down. Because when the controllable switch K disconnects the first resistor R1, if the above-mentioned high-current load continues to work, the voltage division of the first resistor R1 will be too high and the voltage on the subsequent load will be too low to cause it to fail to work, especially When the first resistor R1 is a PTC resistor, if its current is large and the temperature rise of its resistance exceeds the temperature value of the Curie point, its resistance value will jump to a very high value, making the borne very high voltage division and the subsequent load working voltage will be pulled Too low and it won't work.

The inverter air conditioner control method provided by the embodiment of the present invention detects the AC voltage value in real time, and when the AC voltage value is lower than the first preset value, the controllable switch K is controlled to be turned off, so as to control the DC voltage to pass through the first resistor R1 to The electrolytic capacitor E1 is charged, and when the DC voltage value is higher than the second preset value, the controllable switch K is controlled to close, so as to control the DC voltage to finish charging the electrolytic capacitor E1 through the first resistor R1, wherein the second preset value is greater than The first default value. In the control method of the inverter air conditioner of the present invention, when the externally loaded AC voltage fluctuates rapidly, the switch K is disconnected in time and connected to the first resistor R1, so that the first resistor R1 can limit the charging current of the electrolytic capacitor E1 function, thereby avoiding the charging current of the electrolytic capacitor E1 being too large when the controllable switch K is always closed in the prior art and damaging components such as rectifiers, and improving the reliability of the control circuit board of the inverter air conditioner.

The present invention also provides a control device for an inverter air conditioner, which can be used in the outdoor control circuit board of the inverter air conditioner to provide DC power for outdoor loads such as compressors and outdoor fan motors. As shown in Figure 1, the inverter air conditioner control device includes a first resistor R1, a controllable switch K, a voltage detection circuit 10, a rectifier 20, an electrolytic capacitor E1, a load 40, and a controller 30, and the first resistor R1 is connected in series with the input AC Between one terminal and an input terminal of the rectifier 20, the controllable switch K is connected in parallel with the first resistor R1, the rectifier 20 is used to rectify the input AC power and output a DC voltage, the DC voltage supplies power to the load 40, and the voltage detection circuit 10 is used for Detecting the input AC voltage value of the inverter air conditioner control device, the controller 30 controls the action of the controllable switch K according to the supply voltage value detected by the voltage detection current, so as to control the DC voltage to charge the electrolytic capacitor E1.

The control device of the inverter air conditioner according to the embodiment of the present invention further has a specific circuit as shown in FIG. The P2I/O port control of the MCU, the voltage detection circuit 10 detects that the AC voltage value is input to the P2 port of the MCU, the load 40 is composed of a compressor and an IPM module (Intelligent Power Module, Intelligent Power Module) that drives its work, and the MCU passes The six-way IPM driving signals are input to the IPM module to realize the operation control of the compressor. The rectifier 20 is a full-bridge rectifier module BR1, which converts AC power into DC power. The inductor L is connected in series between the positive output terminal of the full-bridge rectifier module BR1 and the electrolytic capacitor E1, so as to realize power factor correction for DC power. As shown in FIG. 3 , the controller 30 includes: a processor 31 and a memory 32. The memory 32 stores an application program 33. The application program 33 is an inverter air conditioner control program. In addition to storing the application program 32, other control parameters can also be stored. The processor 31 executes the application program 33 stored in the memory of the air conditioner, and controls the action of the controllable switch K through the AC voltage value input from the voltage detection circuit 10, so as to realize the DC voltage to charge the electrolytic capacitor.

The control method for the processor 31 to execute the program is the same as the first embodiment of the control method for the inverter air conditioner of the present invention, and will not be repeated here.

The present invention also proposes a computer-readable storage medium. The computer-readable storage medium stores an inverter air conditioner control program, and the inverter air conditioner control program implements the steps of the inverter air conditioner control method in the first to embodiment above. Above-mentioned computer-readable storage medium can be the memory 32 that is arranged in controller 30 as described in Figure 3 and is connected with processor 31, as FLASH memory, or the portable memory that can be moved and used, and above-mentioned memory also can be integrated in processing In the device 31, it is a built-in memory of the processor 31.

In the description of this specification, descriptions with reference to the terms "first embodiment", "second embodiment", "example" and the like mean that the specific methods, devices or features described in conjunction with the embodiment or example are included in the scope of the present invention. In at least one embodiment or example. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, methods, devices or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields , are all included in the scope of patent protection of the present invention in the same way.

Claims (10)

1. A control method of a variable frequency air conditioner is applied to a control device of the variable frequency air conditioner, the control device of the variable frequency air conditioner comprises a first resistor, a controllable switch, a voltage detection circuit, a rectifier, an electrolytic capacitor, a load and a controller, wherein the first resistor is connected between one end of input alternating current and one input end of the rectifier in series, the controllable switch is connected with the first resistor in parallel, the rectifier is used for rectifying the input alternating current to output direct current voltage, the direct current voltage supplies power to the load, the voltage detection circuit is used for detecting an input alternating current voltage value of the control device of the variable frequency air conditioner, and the controller controls the controllable switch to act according to the input alternating current voltage value so as to control the direct current voltage to charge the electrolytic capacitor; the control method comprises the following steps:

sampling the alternating voltage value;

when the alternating voltage value is lower than a first preset value, the controllable switch is controlled to be switched off so as to control the direct voltage to charge the electrolytic capacitor through the first resistor;

and when the alternating voltage value is higher than a second preset value, controlling the controllable switch to be closed so as to control the direct voltage to finish charging the electrolytic capacitor through the first resistor, wherein the second preset value is larger than the first preset value.

2. The inverter air conditioner control method of claim 1, wherein: when the alternating voltage value is lower than a first preset value, the step of controlling the controllable switch to be switched off further comprises the following steps:

controlling the load to be closed.

3. The inverter air conditioner control method of claim 1, wherein: when the alternating voltage value is higher than a second preset value, the step of controlling the controllable switch to be closed specifically comprises the following steps:

and when the alternating voltage value is detected to be higher than a second preset value and lasts for a preset time, controlling the controllable switch to be closed.

4. The inverter air conditioner control method of claim 3, wherein: the preset time range is 0.5-3S.

5. The inverter air conditioner control method of claim 1, wherein:

when the input alternating voltage is 220V, the value range of the first preset value is 75-85V, and the value range of the second preset value is 125-145V.

6. The control device of the variable frequency air conditioner is characterized by comprising a first resistor, a controllable switch, a voltage detection circuit, a rectifier, an electrolytic capacitor, a load and a controller, wherein the first resistor is connected between one end of input alternating current and one input end of the rectifier in series, the controllable switch is connected with the first resistor in parallel, the rectifier is used for rectifying the input alternating current to output direct current voltage, the direct current voltage supplies power to the load, the voltage detection circuit is used for detecting an input alternating current voltage value of the control device of the variable frequency air conditioner, and the controller controls the controllable switch to act according to the input alternating current voltage value so as to control the direct current voltage to charge the electrolytic capacitor; wherein,

the controller comprises a memory, a processor, an inverter air conditioner control program already stored in the memory and executable on the processor, which when executed by the processor implements the inverter air conditioner control method steps of any of claims 1-5.

7. The inverter air conditioner control device according to claim 6, wherein the voltage detection circuit includes a second resistor and a third resistor,

one end of the second resistor is connected with the alternating current L line, the other end of the second resistor is connected with one end of the third resistor, the other end of the third resistor is connected with the alternating current N line, and the connection point of the second resistor and the third resistor is the output end of the voltage detection circuit.

8. The inverter air conditioner control device according to claim 6,

the load comprises an intelligent power module and a compressor connected with the intelligent power module.

9. The inverter air conditioner control device according to claim 6,

the first resistor is a PTC resistor or a cement resistor.

10. A computer-readable storage medium, wherein the computer-readable storage medium stores an inverter air conditioner control program, which when executed by a processor implements the inverter air conditioner control method steps of any of claims 1-5.