阅读说明：本技术 倍压电路、故障检测方法、空调器和可读存储介质 (Voltage doubling circuit, fault detection method, air conditioner and readable storage medium ) 是由 袁光 于 2020-03-25 设计创作，主要内容包括：本发明提供了一种倍压电路、故障检测方法、空调器和可读存储介质。其中,倍压电路包括：并联的第一升压型电路和第二升压型电路,第一升压型电路设有用于进行调制的第一开关器件,第二升压型电路设有用于进行调制的第二开关器件；采样电阻,第一开关器件和第二开关器件的公共端连接至采样电阻的第一端,采样电阻的第二端连接至地线,采样电阻被配置为检测流经第一升压型电路和/或第二升压型电路的电流值,其中,电流值被配置为确定倍压电路的故障信息。通过本发明的技术方案,提高了倍压电路的可靠性和使用寿命,在运行期间的任何时刻都可有效进行检测,没有负载功率的限制。(The invention provides a voltage doubling circuit, a fault detection method, an air conditioner and a readable storage medium. Wherein, voltage doubling circuit includes: the circuit comprises a first boost circuit and a second boost circuit which are connected in parallel, wherein the first boost circuit is provided with a first switching device for modulation, and the second boost circuit is provided with a second switching device for modulation; the sampling resistor is connected to a first end of the sampling resistor, a second end of the sampling resistor is connected to the ground line, and the sampling resistor is configured to detect a current value flowing through the first boost-type circuit and/or the second boost-type circuit, wherein the current value is configured to determine fault information of the voltage doubling circuit. By the technical scheme, the reliability and the service life of the voltage doubling circuit are improved, the voltage doubling circuit can be effectively detected at any time during operation, and the limitation of load power is avoided.)

1. A voltage doubling circuit, comprising:

the circuit comprises a first boost circuit and a second boost circuit which are connected in parallel, wherein the first boost circuit is provided with a first switching device for modulation, and the second boost circuit is provided with a second switching device for modulation;

a sampling resistor, a common terminal of the first switching device and the second switching device being connected to a first terminal of the sampling resistor, a second terminal of the sampling resistor being connected to ground, the sampling resistor being configured to detect a value of a current flowing through the first boost-type circuit and/or the second boost-type circuit,

wherein the current value is configured to determine fault information of the voltage doubling circuit.

2. The voltage doubling circuit of claim 1, further comprising:

a controller having a sampling terminal connected to the sampling resistor, the controller configured to be able to determine a value of current flowing through the sampling resistor.

3. A fault detection method applied to the voltage doubling circuit according to claim 1 or 2, wherein the fault detection method comprises:

determining a duty cycle of a drive signal for driving the first boost-type circuit and the second boost-type circuit;

determining the value of current flowing through the sampling resistor;

and determining fault information of the voltage doubling circuit according to the duty ratio and the current value.

4. The method according to claim 3, wherein determining the fault information of the voltage doubling circuit according to the duty ratio and the current value specifically comprises:

judging whether the duty ratio is larger than a preset duty ratio or not;

judging that the duty ratio is larger than the preset duty ratio, calculating the current value of the sampling resistor at a first sampling moment and a second sampling moment, and respectively recording the current values as a first sampling current and a second sampling current;

and determining fault information of the voltage doubling circuit according to a current difference value between the first sampling current and the second sampling current.

5. The method according to claim 4, wherein determining the fault information of the voltage doubling circuit according to a current difference between the first sampling current and the second sampling current includes:

judging whether the current difference value is larger than or equal to a first current threshold value;

determining that the current difference is greater than or equal to the first current threshold, determining that a one-way fault exists in the voltage doubling circuit,

wherein the first current threshold is determined by an inductance value of the voltage doubling circuit and a supply voltage of the voltage doubling circuit.

6. The fault detection method according to claim 4 or 5, further comprising:

calculating the difference between the middle moment of the conduction duration and the quarter moment of the driving period, and determining the difference result as the first sampling moment;

and/or calculating the sum of the middle moment of the conduction duration and the quarter moment of the driving period, and determining the sum result as the second sampling moment.

7. The method according to claim 3, wherein determining the fault information of the voltage doubling circuit according to the duty ratio and the current value further comprises:

judging whether the duty ratio is smaller than or equal to a preset duty ratio;

judging that the duty ratio is smaller than or equal to the preset duty ratio, calculating the current value of the sampling resistor at a third sampling moment and a fourth sampling moment, and respectively recording the current values as a third sampling current and a fourth sampling current;

and determining fault information of the voltage doubling circuit according to the third sampling current and/or the fourth sampling current.

8. The method according to claim 7, wherein determining the fault information of the voltage doubling circuit according to the third sampling current and/or the fourth sampling current specifically comprises:

judging whether the third sampling current is smaller than or equal to a second current threshold value and/or judging whether the fourth sampling current is smaller than or equal to the second current threshold value;

determining that the third sampled current is less than or equal to the second current threshold, and/or determining that the fourth sampled current is less than or equal to the second current threshold, determining that a one-way damage fault exists in the voltage doubling circuit,

wherein the second current threshold is a minimum current value determined according to a detection accuracy of the controller.

9. The fault detection method according to claim 7 or 8, further comprising:

calculating the middle moment of the conduction time length and determining the middle moment as the third sampling moment;

and/or calculating the sum of the middle moment of the conduction time length and the middle moment of the driving period, and determining the sum result as the fourth sampling moment.

10. An air conditioner, comprising:

a voltage doubler circuit;

a fault detection device connected to the voltage doubling circuit, the fault detection device comprising a memory and a processor, the memory being configured to be able to store a computer program, the computer program being able to carry out the steps of the fault detection method according to any one of claims 3 to 9 when executed by the processor.

11. A computer-readable storage medium, having stored thereon a computer program which, when executed, implements the fault detection method of any one of claims 3 to 9.

Technical Field

The invention relates to the technical field of circuits, in particular to a voltage doubling circuit, a fault detection method, an air conditioner and a computer readable storage medium.

Background

At present, some external vehicle air conditioners adopt a low-voltage storage battery (12v-48v) for power supply, and the power is increased to high voltage through a two-phase staggered parallel voltage-multiplying circuit so as to meet the operation requirement of the air conditioner. The booster circuit has high efficiency, and the voltage stress born by two ends of the power device is half of the output voltage, thereby effectively reducing the requirement on the voltage withstanding characteristic of the power device and greatly reducing the cost.

However, if any one of the two paths of the booster circuit is damaged in the production or operation process, the other path of the booster circuit is greatly loaded and loses the voltage doubling effect, and the voltage borne by the power device is twice that in the normal operation process, so that the booster circuit is extremely easy to damage, and even causes more serious consequences such as explosion, fire and the like, so that the fault can be effectively diagnosed in the production or operation process, and corresponding protection actions are particularly necessary, and the existing fault detection method and the defects are as follows:

(1) whether one-way damage exists is judged according to the theoretical equivalent relation of the duty ratio and the actual boost ratio of the driving switching device, however, the judgment can be only carried out when the output power is large and the booster circuit enters a CCM mode, whether damage exists cannot be judged when the output power is small, and circuit risks may exist when the output power is large.

(2) And the sampling resistors are respectively arranged in the two channels for current collection, and the judgment is carried out according to the existence of the current, so that the hardware cost is high, and the power consumption of the circuit is large.

Moreover, any discussion of the prior art throughout the specification is not an admission that the prior art is necessarily known to a person of ordinary skill in the art, and any discussion of the prior art throughout the specification is not an admission that the prior art is necessarily widely known or forms part of common general knowledge in the field.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art or the related art.

Therefore, an object of the present invention is to provide a voltage doubler circuit.

It is another object of the present invention to provide a fault detection method.

Another object of the present invention is to provide an air conditioner.

It is another object of the present invention to provide a computer-readable storage medium.

In order to achieve the above object, according to an embodiment of a first aspect of the present invention, there is provided a voltage doubler circuit including: the circuit comprises a first boost circuit and a second boost circuit which are connected in parallel, wherein the first boost circuit is provided with a first switching device for modulation, and the second boost circuit is provided with a second switching device for modulation; a sampling resistor, a common terminal of the first switching device and the second switching device being connected to a first terminal of the sampling resistor, a second terminal of the sampling resistor being connected to ground, the sampling resistor being configured to detect a value of a current flowing through the first boost-type circuit and/or the second boost-type circuit, wherein the value of the current is configured to determine fault information of the voltage-doubler circuit.

In the technical scheme, the current flowing through the first switch device and/or the second switch device is detected through the sampling resistor, whether faults exist in the first switch device and the second switch device can be detected at any time according to the current value, namely whether single-path fault information exists, and the reliability and accuracy of fault detection of the voltage doubling circuit are improved based on the real-time performance of the current value, the hardware cost is low, and popularization and production are facilitated.

In any of the above technical solutions, preferably, the method further includes: a controller having a sampling terminal connected to the sampling resistor, the controller configured to be able to determine a value of current flowing through the sampling resistor.

In the technical scheme, the current value of the sampling resistor is determined by the controller, and the current value is calculated to determine whether the single-path damage fault exists, so that the reliability and the accuracy of fault detection are further improved.

According to a second aspect of the present invention, there is provided a fault detection method, including: determining a duty cycle of a drive signal for driving the first boost-type circuit and the second boost-type circuit; determining the value of current flowing through the sampling resistor; and determining fault information of the voltage doubling circuit according to the duty ratio and the current value.

In the technical scheme, the duty ratio of the driving signals for driving the first boost circuit and the second boost circuit is determined, the current value flowing through the sampling resistor is determined, and based on the duty ratio and the current value, the fault information of the voltage doubling circuit is determined according to the duty ratio and the current value, so that the reliability and the accuracy of fault detection on the voltage doubling circuit are improved, the hardware cost is low, and the popularization and the production are facilitated.

In any one of the above technical solutions, preferably, determining fault information of the voltage doubling circuit according to the duty ratio and the current value specifically includes: judging whether the duty ratio is larger than a preset duty ratio or not; judging that the duty ratio is larger than the preset duty ratio, calculating the current value of the sampling resistor at a first sampling moment and a second sampling moment, and respectively recording the current values as a first sampling current and a second sampling current; and determining fault information of the voltage doubling circuit according to a current difference value between the first sampling current and the second sampling current.

In the technical scheme, the fault information of the voltage doubling circuit is determined by judging whether the duty ratio is larger than a preset duty ratio or not and according to the current difference value between the first sampling current and the second sampling current when the duty ratio is judged to be larger than the preset duty ratio, so that the reliability and the accuracy of fault detection are further improved.

For example, the preset duty ratio is 50%, when the PWM duty ratio is greater than 50%, if one of the paths is damaged and does not work any more, the current on the sampling resistor is only the current flowing through one of the paths, the switching device is turned on, the inductive element is charged, the current rises at a fixed slope in the turn-on period corresponding to Ton, and at this time, the current is sampled according to the T/2 cycle, and it is found that the difference between the current values of the two adjacent paths is large, and based on this, the single-path damage fault can be detected accurately and timely.

In any of the above technical solutions, preferably, determining fault information of the voltage doubling circuit according to a current difference between the first sampling current and the second sampling current specifically includes: judging whether the current difference value is larger than or equal to a first current threshold value; and determining that the current difference value is greater than or equal to a first current threshold value, and determining that the voltage doubling circuit has a one-way damage fault, wherein the first current threshold value is determined by the inductance value of the voltage doubling circuit and the supply voltage of the voltage doubling circuit.

In the technical scheme, whether the current difference value is larger than or equal to a first current threshold value or not is judged, and the voltage doubling circuit is determined to have a single-path damage fault when the current difference value is larger than or equal to the first current threshold value, namely, the difference between two adjacent current values is determined to be larger through accurate calculation, so that the single-path damage fault can be detected accurately and timely.

The first current threshold is determined by the inductance value of the voltage doubling circuit and the supply voltage of the voltage doubling circuit, so that the fault detection scheme is applicable to any voltage doubling circuit, namely the first current threshold can be flexibly set according to specific elements of the voltage doubling circuit and written into the controller.

In any of the above technical solutions, preferably, the method further includes: calculating the difference between the middle moment of the conduction duration and the quarter moment of the driving period, and determining the difference result as the first sampling moment; and/or calculating the sum of the middle moment of the conduction duration and the quarter moment of the driving period, and determining the sum result as the second sampling moment.

In the technical scheme, the conduction time is recorded as Ton, the driving period is recorded as T, the first sampling time is Ton/2-T/4, and the second sampling time is Ton/2+ T/4.

In any one of the above technical solutions, preferably, determining fault information of the voltage doubling circuit according to the duty ratio and the current value further includes: judging whether the duty ratio is smaller than or equal to a preset duty ratio; judging that the duty ratio is smaller than or equal to the preset duty ratio, calculating the current value of the sampling resistor at a third sampling moment and a fourth sampling moment, and respectively recording the current values as a third sampling current and a fourth sampling current; and determining fault information of the voltage doubling circuit according to the third sampling current and/or the fourth sampling current.

In the technical scheme, by judging whether the duty ratio is smaller than or equal to a preset duty ratio or not, and judging whether the duty ratio is smaller than or equal to the preset duty ratio or not, the current value of the sampling resistor is calculated at a third sampling moment and a fourth sampling moment, the current values are respectively recorded as a third sampling current and a fourth sampling current, and the fault information of the voltage doubling circuit is determined according to the third sampling current and/or the fourth sampling current.

For example, the predetermined duty ratio is 50%, and when the PWM duty ratio is less than 50%, the third sampling current I3 and the fourth sampling current I4 have no overlapping portion because the time of each current is shorter than T/2. At this time, if the system normally operates, the front T/2 and the rear T/2 currents of the Rs are the same, when one path is damaged, the current corresponding to the T/2 time of the damaged path is 0, and the current of the other path is doubled.

In any of the above technical solutions, preferably, determining the fault information of the voltage doubling circuit according to the third sampling current and/or the fourth sampling current specifically includes: judging whether the third sampling current is smaller than or equal to a second current threshold value and/or judging whether the fourth sampling current is smaller than or equal to the second current threshold value; and determining that the third sampling current is smaller than or equal to the second current threshold value, and/or determining that the fourth sampling current is smaller than or equal to the second current threshold value, and determining that the voltage doubling circuit has a single-circuit damage fault, wherein the second current threshold value is a minimum current value determined according to the detection accuracy of a controller.

In the technical scheme, the voltage doubling circuit is determined to have the one-way damage fault by judging that the third sampling current is smaller than or equal to the second current threshold and/or judging that the fourth sampling current is smaller than or equal to the second current threshold, wherein the second current threshold is a minimum current value determined according to the detection precision of the controller, namely the minimum current value capable of being detected by the controller, and based on the minimum current value, whether the current of one circuit is approximately 0 is determined, so that the one-way damage fault of the voltage doubling circuit is determined more accurately.

In any of the above technical solutions, preferably, the method further includes: calculating the middle moment of the conduction time length and determining the middle moment as the third sampling moment; and/or calculating the sum of the middle moment of the conduction time length and the middle moment of the driving period, and determining the sum result as the fourth sampling moment.

In the technical scheme, the conduction time is recorded as Ton, the driving period is recorded as T, the third sampling time is Ton/2, and the fourth sampling time is Ton/2+ T/2.

According to a third aspect of the present invention, there is provided an air conditioner comprising: a voltage doubler circuit; the fault detection device of the voltage-doubling circuit is electrically connected with the voltage-doubling circuit, and comprises a memory and a processor, wherein the memory is used for storing a computer program, and the processor executes the computer program so as to realize the steps of the fault detection method defined by any one of the technical schemes.

According to an aspect of the fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, the computer program, when executed, implementing the fault detection method as defined in any one of the above aspects.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 shows a schematic diagram of a voltage doubling circuit according to an embodiment of the invention;

FIG. 2 shows a schematic flow diagram of a fault detection method according to one embodiment of the invention;

FIG. 3 shows a schematic flow diagram of a fault detection method according to another embodiment of the invention;

FIG. 4 shows a timing diagram of a fault detection scheme of a voltage doubling circuit according to one embodiment of the invention;

FIG. 5 shows a timing diagram of a fault detection scheme for a voltage doubling circuit according to another embodiment of the invention;

FIG. 6 illustrates a schematic block diagram of an air conditioner according to an embodiment of the present invention;

FIG. 7 shows a schematic block diagram of a computer-readable storage medium according to an embodiment of the invention.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

Embodiments of a fault detection method, a fault detection apparatus, an air conditioner, and a computer-readable storage medium according to embodiments of the present invention are described in detail below with reference to fig. 1 to 7.

As shown in fig. 1, a voltage doubling circuit according to an embodiment of the present invention includes: the circuit comprises a first boost type circuit and a second boost type circuit which are connected in parallel, wherein the first boost type circuit is provided with a first switching device Q1 for modulation, and the second boost type circuit is provided with a second switching device Q2 for modulation; a sampling resistor Rs, a common terminal of the first switching device Q1 and the second switching device Q2 being connected to a first terminal of the sampling resistor Rs, a second terminal of the sampling resistor Rs being connected to a ground line, the sampling resistor Rs being configured to detect a value of a current flowing through the first boost-type circuit and/or the second boost-type circuit, wherein the value of the current is configured to determine fault information of the voltage-doubler circuit.

In the technical scheme, the current flowing through the first switching device Q1 and/or the second switching device Q2 is detected by setting the sampling resistor Rs, whether faults exist in the first switching device Q1 and the second switching device Q2 at any time can be detected according to the current value, namely, whether single-path fault information exists, and based on the real-time performance of the current value, the reliability and the accuracy of fault detection of the voltage doubling circuit are improved, the hardware cost is low, and the popularization and the production are facilitated.

In any of the above technical solutions, preferably, the method further includes: a controller having a sampling terminal connected to the sampling resistor Rs, the controller configured to determine a value of current flowing through the sampling resistor Rs.

In the technical scheme, the current value of the sampling resistor Rs is determined by the controller, and the current value is calculated to determine whether the single-path damage fault exists, so that the reliability and the accuracy of fault detection are further improved.

Specifically, the input voltage U of the voltage doubling circuit may be a battery voltage, a voltage between a high voltage bus V + and a low voltage bus V-is denoted as U, the voltage doubling circuit outputs to a load end P, and an electrolytic capacitor E is connected between the load end P and a ground line, and the method includes the following four stages:

in stage 1, the first switching device Q1 and the second switching device Q2 are both in a conducting state, the first inductor L1 and the second inductor L2 store energy, the current of the two inductors rises linearly, and the load is powered by the electrolytic capacitor E.

Wherein a first zener diode DZ1 is provided for the first switching device and a second zener diode DZ2 is provided for the second switching device.

And in the stage 2, the second switching device Q2 is turned off, the first switching device Q1 is kept on, the first inductor L1 continues to store energy, the second inductor L2 is connected with the second voltage-multiplying capacitor C2 in series on one hand to supply energy to the load through the fourth diode D4, on the other hand, the first voltage-multiplying capacitor C1 is charged through the first switching device Q1 and the second diode D2, and the voltage stress borne by the second switching device Q2 is the difference of Vc1 or Vo-Vc 2.

And (3) stage: the second switching device Q2 is turned on, the first switching device Q1 remains on, and the operation process is the same as that of phase 1.

And 4, the first switching device Q1 is turned off, the second switching device Q2 is kept on, the second inductor L2 continues to store energy, the first inductor L1 is connected with the first voltage-multiplying capacitor C1 in series, the first switching device Q1 is turned off, the second switching device Q2 is kept on, the second inductor L2 continues to store energy, the first inductor L1 is connected with the C1 in series, the third diode D3 supplies energy to a load, the second switching device Q2 and the first diode D1 charge the second voltage-multiplying capacitor C2, and the voltage stress borne by the first switching device Q1 is the difference of Vc2 or Vo-Vc 1.

At time t4, the first switching device Q1 turns on, and phase 1 is re-entered to start the next switching cycle.

The sampling current Iq1 of the first switching device and the sampling current Iq2 of the first switching device are both collected through a sampling resistor Rs.

As shown in fig. 2, a fault detection method according to another embodiment of the present invention includes: step S102 of determining a duty ratio of a driving signal for driving the first boost-type circuit and the second boost-type circuit; step S104, determining the value of current flowing through the sampling resistor; and step S106, determining fault information of the voltage doubling circuit according to the duty ratio and the current value.

In the technical scheme, the duty ratio of the driving signals for driving the first boost circuit and the second boost circuit is determined, the current value flowing through the sampling resistor is determined, and based on the duty ratio and the current value, the fault information of the voltage doubling circuit is determined according to the duty ratio and the current value, so that the reliability and the accuracy of fault detection on the voltage doubling circuit are improved, the hardware cost is low, and the popularization and the production are facilitated.

In any one of the above technical solutions, preferably, determining fault information of the voltage doubling circuit according to the duty ratio and the current value specifically includes: judging whether the duty ratio is larger than a preset duty ratio or not; judging that the duty ratio is larger than the preset duty ratio, calculating the current value of the sampling resistor at a first sampling moment and a second sampling moment, and respectively recording the current values as a first sampling current and a second sampling current; and determining fault information of the voltage doubling circuit according to a current difference value between the first sampling current and the second sampling current.

In the technical scheme, the fault information of the voltage doubling circuit is determined by judging whether the duty ratio is larger than a preset duty ratio or not and according to the current difference value between the first sampling current and the second sampling current when the duty ratio is judged to be larger than the preset duty ratio, so that the reliability and the accuracy of fault detection are further improved.

For example, the preset duty ratio is 50%, when the PWM duty ratio is greater than 50%, if one of the paths is damaged and does not work any more, the current on the sampling resistor is only the current flowing through one of the paths, the switching device is turned on, the inductive element is charged, the current rises at a fixed slope in the turn-on period corresponding to Ton, and at this time, the current is sampled according to the T/2 cycle, and it is found that the difference between the current values of the two adjacent paths is large, and based on this, the single-path damage fault can be detected accurately and timely.

In any of the above technical solutions, preferably, determining fault information of the voltage doubling circuit according to a current difference between the first sampling current and the second sampling current specifically includes: judging whether the current difference value is larger than or equal to a first current threshold value; and determining that the current difference value is greater than or equal to a first current threshold value, and determining that the voltage doubling circuit has a one-way damage fault, wherein the first current threshold value is determined by the inductance value of the voltage doubling circuit and the supply voltage of the voltage doubling circuit.

In the technical scheme, whether the current difference value is larger than or equal to a first current threshold value or not is judged, and the voltage doubling circuit is determined to have a single-path damage fault when the current difference value is larger than or equal to the first current threshold value, namely, the difference between two adjacent current values is determined to be larger through accurate calculation, so that the single-path damage fault can be detected accurately and timely.

The first current threshold is determined by the inductance value of the voltage doubling circuit and the supply voltage of the voltage doubling circuit, so that the fault detection scheme is applicable to any voltage doubling circuit, namely the first current threshold can be flexibly set according to specific elements of the voltage doubling circuit and written into the controller.

In any of the above technical solutions, preferably, the method further includes: calculating the difference between the middle moment of the conduction duration and the quarter moment of the driving period, and determining the difference result as the first sampling moment; and/or calculating the sum of the middle moment of the conduction duration and the quarter moment of the driving period, and determining the sum result as the second sampling moment.

In the technical scheme, the conduction time is recorded as Ton, the driving period is recorded as T, the first sampling time is Ton/2-T/4, and the second sampling time is Ton/2+ T/4.

In any one of the above technical solutions, preferably, determining fault information of the voltage doubling circuit according to the duty ratio and the current value further includes: judging whether the duty ratio is smaller than or equal to a preset duty ratio; judging that the duty ratio is smaller than or equal to the preset duty ratio, calculating the current value of the sampling resistor at a third sampling moment and a fourth sampling moment, and respectively recording the current values as a third sampling current and a fourth sampling current; and determining fault information of the voltage doubling circuit according to the third sampling current and/or the fourth sampling current.

In the technical scheme, by judging whether the duty ratio is smaller than or equal to a preset duty ratio or not, and judging whether the duty ratio is smaller than or equal to the preset duty ratio or not, the current value of the sampling resistor is calculated at a third sampling moment and a fourth sampling moment, the current values are respectively recorded as a third sampling current and a fourth sampling current, and the fault information of the voltage doubling circuit is determined according to the third sampling current and/or the fourth sampling current.

For example, the predetermined duty ratio is 50%, and when the PWM duty ratio is less than 50%, the third sampling current I3 and the fourth sampling current I4 have no overlapping portion because the time of each current is shorter than T/2. At this time, if the system normally operates, the front T/2 and the rear T/2 currents of the Rs are the same, when one path is damaged, the current corresponding to the T/2 time of the damaged path is 0, and the current of the other path is doubled.

In any of the above technical solutions, preferably, determining the fault information of the voltage doubling circuit according to the third sampling current and/or the fourth sampling current specifically includes: judging whether the third sampling current is smaller than or equal to a second current threshold value and/or judging whether the fourth sampling current is smaller than or equal to the second current threshold value; and determining that the third sampling current is smaller than or equal to the second current threshold value, and/or determining that the fourth sampling current is smaller than or equal to the second current threshold value, and determining that the voltage doubling circuit has a single-circuit damage fault, wherein the second current threshold value is a minimum current value determined according to the detection accuracy of a controller.

In the technical scheme, the voltage doubling circuit is determined to have the one-way damage fault by judging that the third sampling current is smaller than or equal to the second current threshold and/or judging that the fourth sampling current is smaller than or equal to the second current threshold, wherein the second current threshold is a minimum current value determined according to the detection precision of the controller, namely the minimum current value capable of being detected by the controller, and based on the minimum current value, whether the current of one circuit is approximately 0 is determined, so that the one-way damage fault of the voltage doubling circuit is determined more accurately.

In any of the above technical solutions, preferably, the method further includes: calculating the middle moment of the conduction time length and determining the middle moment as the third sampling moment; and/or calculating the sum of the middle moment of the conduction time length and the middle moment of the driving period, and determining the sum result as the fourth sampling moment.

In the technical scheme, the conduction time is recorded as Ton, the driving period is recorded as T, the third sampling time is Ton/2, and the fourth sampling time is Ton/2+ T/2.

As shown in fig. 3, a fault detection method according to another embodiment of the present invention includes: step S202, judging whether the Duty is more than 50%, if so, executing step S204, otherwise, executing step S206; step S204, setting sampling moments Ton/2-T/4 and Ton/2+ T/4, and collecting current at the sampling moments, namely I1 and I2; s206, setting sampling moments Ton/2 and Ton/2+ T/2, and collecting current at the sampling moments, wherein the current is marked as I3 and I4; step S208, judging whether | I1-I2| Ith1 is true, if yes, executing step S212, and if not, executing step S202; step S210, judging whether any value of I3 and I4 is smaller than Ith2, if yes, executing step S212, and if not, executing step S202; and step S212, the single path is damaged, the air conditioner is forbidden to operate, and prompt is carried out.

With reference to fig. 4 and 5, the following steps of the fault detection scheme of the voltage doubling circuit are described:

step 1: and judging whether the duty ratio of the driving pulse is more than 50%, if so, entering a step 2, otherwise, entering a step 4.

Step 2: the current on Rs is sampled to be greater than 50%, the sampling time is set to Ton/2-T/4 and Ton/2+ T/4, and the corresponding currents are recorded as I1 and I2.

And step 3: comparing Ip and Ic, if the absolute value of the difference is greater than threshold Ith1, considering that the single path is damaged, jumping to step 6, if the absolute value is less than threshold Ith1, considering that no channel is damaged, and returning to step 1 to be executed again in the next period.

And 4, step 4: the current on Rs is sampled to be less than or equal to 50%, the sampling time is set at Ton/2 and Ton/2+ T/2, and the corresponding currents are recorded as Ip and Ic.

And 5: if any one of I3 and I4 is smaller than Ith2, the single path is considered to be damaged, step 6 is executed, otherwise, the step 1 is returned to and executed again in the next period.

Step 6: when the single path is damaged, the machine is stopped immediately, and the display screen reports faults to prompt a user that the air conditioner is in a problem and can not be reused.

Under normal operation, the current Iq1 flowing through the switch tube Q1 is the same as the current Iq2 flowing through the switch tube Q2 but different by T/2. The total current of the two paths, namely the sum of the two paths of current, flows through the sampling resistor Rs, and the period of the total current is changed into T/2. The current Irs on Rs is almost exactly the same every cycle, even though the slight fluctuations are not very large. At this time, the current is sampled at a period of T/2, and the currents are almost the same.

The timing start time of the sampling time in step 2 and step 4 is the time when any of the two Ton paths starts, i.e. the sampling time is synchronized with any of the two Ton paths. Each switching tube has a PWM period of T and a duty ratio of Ton/T, is turned on at the moment of Ton, and is turned off when the current flows through the switching tube and is turned off at the rest moments without current.

In addition, the purpose of the formula is to set the sampling instant at the midpoint of the period of greater current on Rs in normal operation, as shown in fig. 4.

The first current threshold Ith1 is determined by the inductance value L of the inductor and the voltage V of the storage battery used by the product, Ith1 is a × V/L, and a is a margin coefficient and is between 0.5 and 1.

In addition, the second current threshold Ith2 is determined according to the AD conversion accuracy of the MCU and the design quality of the circuit board, which affects the level of circuit interference, and the accuracy of the AD determines the minimum value that can be set.

As shown in fig. 6, the air conditioner 400 according to the embodiment of the present invention includes: a voltage doubler circuit 402; a voltage doubler circuit failure detection apparatus 300, said voltage doubler circuit failure detection apparatus 300 being electrically connected to said voltage doubler circuit 402, said voltage doubler circuit failure detection apparatus 300 comprising a memory for storing a computer program and a processor for executing the computer program to implement the steps of the failure detection method as defined in any one of the above claims.

As shown in fig. 7, according to the computer-readable storage medium 500 of the embodiment of the present invention, the computer-readable storage medium stores a computer program, and when the computer program is executed by the air conditioner 400, the method for detecting a fault as defined in any one of the above technical solutions is implemented, and specifically includes the following steps: determining a duty cycle of a drive signal for driving the first boost-type circuit and the second boost-type circuit; determining the value of current flowing through the sampling resistor; and determining fault information of the voltage doubling circuit according to the duty ratio and the current value.

In the technical scheme, the duty ratio of the driving signals for driving the first boost circuit and the second boost circuit is determined, the current value flowing through the sampling resistor is determined, and based on the duty ratio and the current value, the fault information of the voltage doubling circuit is determined according to the duty ratio and the current value, so that the reliability and the accuracy of fault detection on the voltage doubling circuit are improved, the hardware cost is low, and the popularization and the production are facilitated.

In any one of the above technical solutions, preferably, determining fault information of the voltage doubling circuit according to the duty ratio and the current value specifically includes: judging whether the duty ratio is larger than a preset duty ratio or not; judging that the duty ratio is larger than the preset duty ratio, calculating the current value of the sampling resistor at a first sampling moment and a second sampling moment, and respectively recording the current values as a first sampling current and a second sampling current; and determining fault information of the voltage doubling circuit according to a current difference value between the first sampling current and the second sampling current.

In the technical scheme, the fault information of the voltage doubling circuit is determined by judging whether the duty ratio is larger than a preset duty ratio or not and according to the current difference value between the first sampling current and the second sampling current when the duty ratio is judged to be larger than the preset duty ratio, so that the reliability and the accuracy of fault detection are further improved.

For example, the preset duty ratio is 50%, when the PWM duty ratio is greater than 50%, if one of the paths is damaged and does not work any more, the current on the sampling resistor is only the current flowing through one of the paths, the switching device is turned on, the inductive element is charged, the current rises at a fixed slope in the turn-on period corresponding to Ton, and at this time, the current is sampled according to the T/2 cycle, and it is found that the difference between the current values of the two adjacent paths is large, and based on this, the single-path damage fault can be detected accurately and timely.

In any of the above technical solutions, preferably, determining fault information of the voltage doubling circuit according to a current difference between the first sampling current and the second sampling current specifically includes: judging whether the current difference value is larger than or equal to a first current threshold value; and determining that the current difference value is greater than or equal to a first current threshold value, and determining that the voltage doubling circuit has a one-way damage fault, wherein the first current threshold value is determined by the inductance value of the voltage doubling circuit and the supply voltage of the voltage doubling circuit.

In the technical scheme, whether the current difference value is larger than or equal to a first current threshold value or not is judged, and the voltage doubling circuit is determined to have a single-path damage fault when the current difference value is larger than or equal to the first current threshold value, namely, the difference between two adjacent current values is determined to be larger through accurate calculation, so that the single-path damage fault can be detected accurately and timely.

The first current threshold is determined by the inductance value of the voltage doubling circuit and the supply voltage of the voltage doubling circuit, so that the fault detection scheme is applicable to any voltage doubling circuit, namely the first current threshold can be flexibly set according to specific elements of the voltage doubling circuit and written into the controller.

In any of the above technical solutions, preferably, the method further includes: calculating the difference between the middle moment of the conduction duration and the quarter moment of the driving period, and determining the difference result as the first sampling moment; and/or calculating the sum of the middle moment of the conduction duration and the quarter moment of the driving period, and determining the sum result as the second sampling moment.

In the technical scheme, the conduction time is recorded as Ton, the driving period is recorded as T, the first sampling time is Ton/2-T/4, and the second sampling time is Ton/2+ T/4.

In any one of the above technical solutions, preferably, determining fault information of the voltage doubling circuit according to the duty ratio and the current value further includes: judging whether the duty ratio is smaller than or equal to a preset duty ratio; judging that the duty ratio is smaller than or equal to the preset duty ratio, calculating the current value of the sampling resistor at a third sampling moment and a fourth sampling moment, and respectively recording the current values as a third sampling current and a fourth sampling current; and determining fault information of the voltage doubling circuit according to the third sampling current and/or the fourth sampling current.

In the technical scheme, by judging whether the duty ratio is smaller than or equal to a preset duty ratio or not, and judging whether the duty ratio is smaller than or equal to the preset duty ratio or not, the current value of the sampling resistor is calculated at a third sampling moment and a fourth sampling moment, the current values are respectively recorded as a third sampling current and a fourth sampling current, and the fault information of the voltage doubling circuit is determined according to the third sampling current and/or the fourth sampling current.

For example, the predetermined duty ratio is 50%, and when the PWM duty ratio is less than 50%, the third sampling current I3 and the fourth sampling current I4 have no overlapping portion because the time of each current is shorter than T/2. At this time, if the system normally operates, the front T/2 and the rear T/2 currents of the Rs are the same, when one path is damaged, the current corresponding to the T/2 time of the damaged path is 0, and the current of the other path is doubled.

In any of the above technical solutions, preferably, determining the fault information of the voltage doubling circuit according to the third sampling current and/or the fourth sampling current specifically includes: judging whether the third sampling current is smaller than or equal to a second current threshold value and/or judging whether the fourth sampling current is smaller than or equal to the second current threshold value; and determining that the third sampling current is smaller than or equal to the second current threshold value, and/or determining that the fourth sampling current is smaller than or equal to the second current threshold value, and determining that the voltage doubling circuit has a single-circuit damage fault, wherein the second current threshold value is a minimum current value determined according to the detection accuracy of a controller.

In the technical scheme, the voltage doubling circuit is determined to have the one-way damage fault by judging that the third sampling current is smaller than or equal to the second current threshold and/or judging that the fourth sampling current is smaller than or equal to the second current threshold, wherein the second current threshold is a minimum current value determined according to the detection precision of the controller, namely the minimum current value capable of being detected by the controller, and based on the minimum current value, whether the current of one circuit is approximately 0 is determined, so that the one-way damage fault of the voltage doubling circuit is determined more accurately.

In any of the above technical solutions, preferably, the method further includes: calculating the middle moment of the conduction time length and determining the middle moment as the third sampling moment; and/or calculating the sum of the middle moment of the conduction time length and the middle moment of the driving period, and determining the sum result as the fourth sampling moment.

In the technical scheme, the conduction time is recorded as Ton, the driving period is recorded as T, the third sampling time is Ton/2, and the fourth sampling time is Ton/2+ T/2.

The technical scheme of the invention is described in detail with reference to the accompanying drawings, and the invention provides a voltage doubling circuit, a fault detection method, an air conditioner and a computer readable storage medium.

The steps in the method of the invention can be sequentially adjusted, combined and deleted according to actual needs. The units in the device of the invention can be merged, divided and deleted according to actual needs. It will be understood by those skilled in the art that all or part of the steps in the methods of the embodiments described above may be implemented by instructions associated with hardware, which may be stored in a computer-readable storage medium, such as a Read-Only Memory (ROM), a Random Access Memory (RAM), a Programmable Read-Only Memory (PROM), an Erasable Programmable Read-Only Memory (EPROM), a One-time Programmable Read-Only Memory (OTPROM), an Electrically Erasable rewritable Read-Only Memory (EEPROM), a Compact Disc Read-Only Memory (CD-ROM), or other Memory, a magnetic disk, a magnetic tape, or a magnetic tape, Or any other medium which can be used to carry or store data and which can be read by a computer. The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.