CN115459571A - Magnetic ring overheating protection method, system, device, equipment and medium - Google Patents
Magnetic ring overheating protection method, system, device, equipment and medium Download PDFInfo
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- CN115459571A CN115459571A CN202211123740.5A CN202211123740A CN115459571A CN 115459571 A CN115459571 A CN 115459571A CN 202211123740 A CN202211123740 A CN 202211123740A CN 115459571 A CN115459571 A CN 115459571A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
- H02M1/327—Means for protecting converters other than automatic disconnection against abnormal temperatures
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/493—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode the static converters being arranged for operation in parallel
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Abstract
The invention discloses a magnetic ring overheat protection method, a system, a device, equipment and a medium of an inverter parallel system, wherein the method is applied to a control unit in the magnetic ring overheat protection system, the magnetic ring overheat protection system also comprises a current sampling unit, a controlled switch, a direct current power supply and a winding which is arranged aiming at a magnetic ring in the inverter parallel system, and the method comprises the following steps: receiving power frequency circulation of the inverter parallel system collected by the current sampling unit; and when the inverter parallel system is detected to meet the preset magnetic ring overheat protection triggering condition, controlling the controlled switch to be closed so as to switch on a direct current loop between the direct current power supply and the winding, wherein the direct current bias added to the magnetic ring by the winding is larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring due to the current output by the direct current power supply. The magnetic ring overheating protection scheme of the inverter parallel system can avoid safety accidents caused by overheating of the magnetic ring due to power frequency circulation generated by the inverter parallel system.
Description
Technical Field
The invention relates to the technical field of circuit control, in particular to a magnetic ring overheating protection method, system, device, equipment and medium for an inverter parallel system.
Background
At present, to solve the EMI (Electromagnetic Interference) problem, a magnetic ring is usually required to be disposed between the ac filter capacitor and the ac output terminal of the inverter to suppress the common mode noise. In inverter parallel systems, power frequency circulating currents may be generated between the parallel inverters, and may reach the order of tens of amperes (a). When no power frequency circulating current exists, the total power frequency current flowing through the magnetic ring is 0, the magnetic ring can work normally and hardly generates heat, but when the power frequency circulating current is generated in the inverter parallel system, the power frequency circulating current flows through the added magnetic ring completely, the loss of the magnetic ring is increased rapidly, and the most serious condition is local overheating, so that the self and the nearby insulating materials are invalid, and safety accidents are caused.
Disclosure of Invention
The invention mainly aims to provide a method, a system, a device, equipment and a medium for protecting magnetic ring overheating of an inverter parallel system, and aims to provide a scheme for protecting the magnetic ring overheating of the inverter parallel system so as to avoid safety accidents caused by magnetic ring overheating caused by power frequency circulation generated by the inverter parallel system.
In order to achieve the above object, the present invention provides a method for protecting a magnetic ring from overheating of an inverter parallel system, where the method is applied to a control unit in the magnetic ring overheating protection system, the magnetic ring overheating protection system further includes a current sampling unit, a controlled switch, a dc power supply, and a winding arranged for a magnetic ring in the inverter parallel system, and the method includes:
receiving the power frequency circulation of the inverter parallel system collected by the current sampling unit;
and when the inverter parallel system is detected to meet a preset magnetic ring overheat protection triggering condition, controlling the controlled switch to be closed so as to switch on a direct current loop between the direct current power supply and the winding, wherein the current output by the direct current power supply enables the direct current bias added to the magnetic ring by the winding to be larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring.
Optionally, before the step of controlling the controlled switch to be closed, the method further includes:
and when the power frequency circulating current is detected to be larger than a first threshold value, determining that the magnetic ring overheating protection triggering condition is met.
Optionally, after the step of receiving the power frequency circulating current of the inverter parallel system collected by the current sampling unit, the method further includes:
and when the power frequency circulating current is smaller than a second threshold value, controlling the controlled switch to be switched on so as to disconnect a direct current loop between the direct current power supply and the winding, wherein the second threshold value is smaller than the first threshold value.
Optionally, the magnetic ring overheating protection system further includes a temperature acquisition unit, and before the step of controlling the controlled switch to be closed, the method further includes:
receiving the temperature value of the magnetic ring acquired by the temperature acquisition unit;
and when the temperature value is detected to be larger than a third threshold value, determining that the magnetic ring overheating protection triggering condition is met.
Optionally, after the step of receiving the power frequency circulating current of the inverter parallel system collected by the current sampling unit, the method further includes:
when the inverter parallel system is detected to meet the magnetic ring overheating protection condition, calculating the sum of the power frequency circulating current and the saturation current of the magnetic ring to obtain target direct current bias;
calculating to obtain a target current value according to the target direct current bias and the number of turns of the winding;
and controlling the direct current power supply to output direct current with the target current value.
Optionally, the magnetic ring overheating protection system further includes an early warning unit, and after the step of controlling the controlled switch to be closed, the method further includes:
timing the duration of the state duration that the inverter parallel system meets the magnetic ring overheat protection condition from the closing of the controlled switch;
and when the timing duration is longer than the preset duration, controlling the early warning unit to output an early warning prompt.
In order to achieve the above object, the present invention further provides a magnetic ring overheat protection system for an inverter parallel system, which includes a current sampling unit, a control unit, a controlled switch, a dc power supply and a winding arranged for a magnetic ring in the inverter parallel system;
the current sampling unit is used for collecting the power frequency circulation of the inverter parallel system and outputting the power frequency circulation to the control unit;
the controlled switch is controlled by the control unit and is used for switching on or switching off a direct current loop between the direct current power supply and the winding;
the current output by the direct current power supply enables the direct current bias added to the magnetic ring by the winding to be larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring;
the control unit is used for executing the magnetic ring overheating protection method of the inverter parallel system.
Optionally, the controlled switch is disposed outside the dc power supply, and is configured to cut off at least one connection line between the dc power supply and the winding.
Optionally, the controlled switch is disposed inside the dc power supply, and an inductor is disposed on one of the connection lines between the dc power supply and the winding, or an inductor is disposed on each of the two connection lines, or a differential mode inductor is disposed on each of the two connection lines.
In order to achieve the above object, the present invention further provides a magnetic ring overheat protection device for an inverter parallel system, the device is applied to a control unit in the magnetic ring overheat protection system, the magnetic ring overheat protection system further includes a current sampling unit, a controlled switch, a dc power supply and a winding arranged for a magnetic ring in the inverter parallel system, the device includes:
the receiving module is used for receiving the power frequency circulating current of the inverter parallel system collected by the current sampling unit;
and the control module is used for controlling the controlled switch to be closed when the inverter parallel system is detected to meet a preset magnetic ring overheat protection triggering condition so as to switch on a direct current loop between the direct current power supply and the winding, wherein the direct current bias added to the magnetic ring by the winding is larger than or equal to the sum of the power frequency loop current and the saturation current of the magnetic ring due to the current output by the direct current power supply.
In order to achieve the above object, the present invention further provides a magnetic ring overheat protection device, including: the magnetic ring overheating protection method comprises a memory, a processor and a magnetic ring overheating protection program stored on the memory and capable of running on the processor, wherein the steps of the magnetic ring overheating protection method are realized when the magnetic ring overheating protection program is executed by the processor.
In addition, to achieve the above object, the present invention further provides a computer readable storage medium, on which a magnetic ring overheat protection program is stored, and the magnetic ring overheat protection program, when executed by a processor, implements the steps of the magnetic ring overheat protection method as described above.
In the invention, a magnetic ring overheating protection system of an inverter parallel system is arranged, wherein the magnetic ring overheating protection system comprises a control unit, a current sampling unit, a controlled switch, a direct-current power supply and a winding which is arranged aiming at a magnetic ring in the inverter parallel system; the control unit receives the power frequency circulating current of the inverter parallel system collected by the current sampling unit, and when the inverter parallel system is detected to meet the triggering condition of magnetic ring overheat protection, the control unit controls the controlled switch to be closed so as to switch on the direct current loop between the direct current power supply and the winding, wherein the direct current bias added to the magnetic ring by the winding is larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring due to the current output by the direct current power supply. The invention realizes a magnetic ring overheating protection scheme of the inverter parallel system, and avoids safety accidents caused by overheating of the magnetic ring due to power frequency circulating current generated by the inverter parallel system.
Drawings
Fig. 1 is a schematic flow chart of a magnetic ring overheat protection method according to a first embodiment of the present invention;
fig. 2 is a schematic view of a magnetic ring overheat protection system according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a magnetic hysteresis loop of a magnetic ring according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a hardware operating environment according to an embodiment of the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
Example one
The embodiment of the invention provides a magnetic ring overheating protection method for an inverter parallel system, which is applied to a control unit in the magnetic ring overheating protection system, wherein the magnetic ring overheating protection system further comprises a current sampling unit, a controlled switch, a direct current power supply and a winding set for a magnetic ring in the inverter parallel system, and referring to fig. 1, the method comprises the following steps:
step S10, receiving the power frequency circulation of the inverter parallel system collected by the current sampling unit;
in this embodiment, the inverter parallel system is a system in which at least two inverters are connected in parallel, and a DC (direct current) input side and an AC (alternating current) output side of each inverter are short-circuited, respectively, so that a power frequency circulating current may be generated. In order to solve the EMI problem, a magnetic ring is usually disposed between the ac filter capacitor and the ac output terminal of the inverter, that is, an ac line between the ac filter capacitor and the ac output terminal is used as a winding resistance of the magnetic ring to suppress common mode noise. When a power frequency circulating current is generated, the power frequency circulating current completely flows through the added magnetic ring, so that the loss of the magnetic ring is increased, and when the power frequency circulating current is large, the magnetic ring is possibly overheated, so that the self and the nearby insulating materials are invalid, and a safety accident is caused.
In order to solve the above problem, in this embodiment, a magnetic ring overheat protection system is provided, where the magnetic ring overheat protection system includes a control unit, a controlled switch, a dc power supply, and a winding disposed for a magnetic ring, and the winding is a newly added winding with respect to an original winding of the magnetic ring. Referring to fig. 2, a schematic diagram of a magnetic ring overheat protection system is shown, but the magnetic ring overheat protection system according to the embodiments of the present invention is not limited to the diagram. In fig. 2, a detection control unit is a control unit, a current limiting source is a direct current power supply, and a winding a is a winding.
The current sampling unit can be used for collecting power frequency circulation and sending the collected power frequency circulation to the control unit. The current sampling unit may be implemented by a hall device or the like, and is not limited in this embodiment. The current sampling unit can be arranged between an alternating current filter capacitor and an alternating current output end of the inverter, the position relation between the current sampling unit and the magnetic ring is not limited, the magnetic ring can be positioned between the current sampling unit and the alternating current output end, and the current sampling unit can also be positioned between the magnetic ring and the alternating current output end.
A connecting wire is arranged between the direct current power supply and the winding, and a direct current loop between the direct current power supply and the winding can be disconnected or connected by controlling the on-off of the controlled switch. When a direct current loop between the direct current power supply and the winding is switched on, direct current output by the direct current power supply flows through the winding, and therefore a direct current bias is added to the magnetic ring. Wherein the dc offset is equal to the dc current output by the dc current multiplied by the number of turns of the winding. The controlled switch is set to be in an on state during initialization, namely, the direct current loop between the direct current power supply and the winding is in an off state during initialization, so that the function of restraining common mode noise can be normally exerted on the magnetic ring.
The control unit is connected with the controlled switch and used for controlling the on-off of the controlled switch.
The control unit can receive the power frequency circulation current collected by the current sampling unit. In a specific embodiment, the current sampling unit can collect the power frequency circulation in real time, and output the collected power frequency circulation to the control unit in real time, and the control unit controls the on and off of the controlled switch in real time based on the power frequency circulation, or the current sampling unit can collect the power frequency circulation at a certain time interval, and the time interval can be controlled within a certain range as required, so that the power consumption of the magnetic ring overheating protection system is reduced, and meanwhile, the safety accident caused by the overheating of the magnetic ring due to the sudden increase of the power frequency circulation is avoided within the time interval.
The control unit can detect whether the inverter parallel system meets the triggering condition of magnetic ring overheat protection. The magnetic ring overheat protection triggering condition may be set as required in advance, for example, the power frequency circulating current in the inverter parallel system may be set to be greater than a certain threshold, and the temperature of the magnetic ring in the inverter parallel system may be set to be greater than a certain threshold.
Further, in an embodiment, the control unit may detect whether the power frequency circulating current is greater than the first threshold after receiving the power frequency circulating current output by the current sampling unit. The first threshold value can be set as required, so that when the power frequency circulating current is below the first threshold value, the magnetic ring can work normally, the temperature rise is within the specification, no heat dissipation measures need to be added, and the specific value is set according to the actual condition. When the power frequency circulating current is detected to be larger than a first threshold value, the control unit determines that the current inverter parallel system meets the magnetic ring overheating protection triggering condition.
And step S20, when the condition that the magnetic ring overheat protection triggering condition is met is detected, the controlled switch is controlled to be closed so as to switch on a direct current loop between the direct current power supply and the winding, wherein the current output by the direct current power supply enables the direct current offset added to the magnetic ring by the winding to be larger than or equal to the sum of the power frequency loop current and the saturation current of the magnetic ring.
When the control unit determines that the inverter parallel system meets the triggering condition of magnetic ring overheat protection, the control unit can control the controlled switch to be closed so as to switch on a direct current loop between the direct current power supply and the winding, so that direct current output by the direct current power supply flows through the winding, and a new direct current bias is added to the magnetic ring. The current output by the direct current power supply can enable the direct current bias added to the magnetic ring by the winding to be larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring, and the saturation current is the minimum current value enabling the magnetic ring to reach a saturation state. There are many ways to achieve this goal, and this embodiment is not limited. For example, in an embodiment, the dc power supply may adopt a constant current source, the current output by the constant current source may be a fixed value that is set in advance according to needs, the fixed value may be determined according to the maximum power frequency circulating current of the inverter parallel system, the saturation current of the magnetic ring, and the number of turns of the winding, assuming that the maximum power frequency circulating current of the inverter parallel system is 30A (effective value), and the saturation current of the magnetic ring is 20A, the dc offset should reach 20+30 × 1.414 ≈ 62A, and then the current output by the dc power supply is calculated according to the dc offset and the number of turns of the winding, for example, when the number of turns is 1, the current output by the dc power supply should be 62A. For another example, in another embodiment, the dc power supply may adopt an adjustable constant current source, and the control unit may calculate the current magnitude to be output by the dc power supply according to the power frequency circulating current received from the current sampling unit, the saturation current of the magnetic loop, and the number of turns of the winding.
It should be noted that, when the inverter parallel system meets the triggering condition of magnetic ring overheat protection, by switching on the dc loop between the dc power supply and the winding, the current output by the dc power supply makes the dc offset added to the magnetic ring by the winding greater than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring, so as to make the magnetic ring reach the saturation state quickly after subtracting the power frequency circulating current from the dc offset of the magnetic ring, and in this state, the relative magnetic permeability of the magnetic ring is reduced to 1, which is equivalent to the vacuum state, so that the power frequency circulating current superposed on the magnetic ring cannot cause the loss of the magnetic ring, thereby thoroughly solving the problems of heating and safety caused by the excessive loss of the magnetic ring.
The principle is explained below with reference to the schematic hysteresis loop diagram of the soft magnetic material shown in fig. 3. When alternating current is applied to a magnetic ring, the loss of the magnetic ring (mainly considering hysteresis loss) is equal to the area contained by a hysteresis loop multiplied by the volume of the magnetic ring multiplied by the current frequency. The smaller the applied alternating current (corresponding to the small value of the abscissa H), the smaller the closed loop formed by the hysteresis loop, the smaller the loss, and when the applied current makes the magnetic field reach H3, the loss reaches a maximum, and then the current is increased, and the increased loss is limited. If a large direct current is superimposed on the alternating current, so that the initial state is far beyond H3, the hysteresis loop contains a very small area and almost no loss.
Further, if the magnetic ring overheating protection triggering condition is set to be that the power frequency circulating current is greater than the first threshold, when the power frequency circulating current is less than or equal to the first threshold, in a specific embodiment, the operation executed by the control unit may be set as needed, which is not limited in this embodiment. For example, in one embodiment, when the power frequency circulating current is less than or equal to the first threshold, if the controlled switch is in the on state, the control unit may not perform processing, and maintain the on state of the controlled switch, thereby ensuring a normal common mode noise suppression function of the magnetic ring; when the power frequency circulating current is smaller than or equal to the first threshold, if the controlled switch is in a closed state, the control unit can control the controlled switch to be opened so as to ensure the normal common mode noise suppression function of the magnetic ring.
In the embodiment, a magnetic ring overheating protection system of the inverter parallel system is arranged, and the magnetic ring overheating protection system comprises a control unit, a current sampling unit, a controlled switch, a direct current power supply and a winding arranged for a magnetic ring in the inverter parallel system; the control unit receives the power frequency circulating current of the inverter parallel system collected by the current sampling unit; when the inverter parallel system is detected to meet the preset magnetic ring overheat protection triggering condition, the control unit controls the controlled switch to be closed so as to switch on a direct current loop between the direct current power supply and the winding, wherein the direct current bias added to the magnetic ring by the winding is larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring due to the size of the current output by the direct current power supply. The embodiment realizes the magnetic ring overheating protection scheme of the inverter parallel system, and avoids safety accidents caused by overheating of the magnetic ring due to power frequency circulation generated by the inverter parallel system.
Compared with the scheme of cooling the magnetic ring by adding the electric fan, the magnetic ring overheating protection system related to the magnetic ring overheating protection scheme in the embodiment has the advantages of simple structure, small volume, no great structural design change for the inverter parallel system, and more convenient deployment and implementation.
Further, in an embodiment, after the step S10, the method further includes:
step S30, when the inverter parallel system is detected to meet the magnetic ring overheating protection condition, calculating the sum of the power frequency circulating current and the saturation current of the magnetic ring to obtain target direct current bias;
when the inverter parallel system meets the magnetic ring overheating protection condition, the control unit can also calculate the sum of the power frequency circulating current and the saturation current of the magnetic ring, and the obtained result is referred to as target direct current bias for distinguishing. It can be understood that when the dc offset of the magnetic loop is greater than or equal to the target dc offset, the magnetic loop must be in saturation.
Step S40, calculating to obtain a target current value according to the target direct current bias and the number of turns of the winding;
the control unit may calculate a current value capable of generating the target dc bias according to the target dc bias and the number of turns of the winding, that is, according to a relationship between the dc bias and the number of turns of the winding, and the target current value may be equal to or greater than the current value as needed. The target dc bias may be divided by the number of windings to obtain a current value capable of generating the target dc bias.
And S50, controlling the direct current power supply to output direct current with the target current value.
In the embodiment, a target current value meeting the requirement is calculated according to the collected power frequency circulating current, and the direct current power supply is controlled to output the direct current with the target current value, so that on one hand, the magnetic ring overheating protection system can achieve the overheating protection effect with the minimum power consumption, and on the other hand, the magnetic ring overheating protection system can be suitable for various inverter parallel systems without setting different magnetic ring overheating protection systems for different inverter parallel systems.
Further, in an embodiment, when the triggering condition of the magnetic ring overheat protection is that the power frequency circulating current is greater than the first threshold, after step S10, the method further includes:
and S60, when the power frequency circulating current is smaller than a second threshold value, controlling the controlled switch to be turned on so as to cut off a direct current loop between the direct current power supply and the winding, wherein the second threshold value is smaller than the first threshold value.
And after receiving the power frequency circulating current output by the current sampling unit, the control unit can also detect whether the power frequency circulating current is smaller than a second threshold value. The second threshold is smaller than the first threshold, for example, smaller than 5A, and the specific value can be set as required, and the purpose of setting the second threshold smaller than the first threshold is to avoid the controlled switch from repeatedly acting. When the control unit detects that the power frequency circulating current is smaller than a second threshold value, the controlled switch is controlled to be started so as to cut off a direct current loop between the direct current power supply and the winding, and therefore the normal common mode noise suppression function of the magnetic ring is guaranteed.
It can be understood that when the controlled switch is in an on state, if the power frequency circulating current is greater than a first threshold, the controlled switch is controlled to be closed so as to avoid safety accidents caused by overheating of the magnetic ring, and if the power frequency circulating current is less than or equal to the first threshold, the controlled switch is continuously in the on state so as to ensure the normal common mode noise suppression function of the magnetic ring; when the controlled switch is in a closed state, if the power frequency circulating current is smaller than a second threshold value, the controlled switch is controlled to be opened so as to ensure the normal common mode noise suppression function of the magnetic ring, and if the power frequency circulating current is larger than or equal to the second threshold value, the controlled switch is continuously in a closed state so as to avoid safety accidents caused by overheating of the magnetic ring.
Example two
On the basis of the first embodiment, the step of controlling the controlled switch to be closed in step S20 in the above embodiment may further include step a10 and step a20, and the magnetic ring overheat protection system may further include a temperature acquisition unit, which will be described below. In this embodiment, the same or similar contents as those in the first and second embodiments may refer to the above description, and are not repeated hereinafter.
Step A10, receiving the temperature value of the magnetic ring acquired by the temperature acquisition unit;
in this embodiment, the triggering condition of the magnetic ring overheat protection may be that the temperature value of the magnetic ring is greater than a certain threshold. And a temperature acquisition unit is also arranged in the magnetic ring overheating protection system and used for acquiring the temperature value of the magnetic ring.
The specific implementation manner of the temperature acquisition unit is not limited in this embodiment, and for example, the temperature acquisition unit may be implemented by using a conventional temperature sensor. The temperature acquisition unit can be arranged at a position close to the magnetic ring, so that accurate magnetic ring temperature values can be acquired.
The temperature acquisition unit outputs the acquired temperature value to the control unit. Similarly to the current collection unit, the temperature collection unit may also collect temperature values in real time or at certain time intervals.
And A20, when the temperature value is detected to be larger than a third threshold value, determining that the triggering condition of the magnetic ring overheat protection is met.
The third threshold may be set as needed, and is not limited herein. When the temperature value of the magnetic ring is greater than the third threshold value, the temperature of the magnetic ring is high, and the continuous temperature rise may cause safety accidents. When the temperature value is greater than the third threshold value, the control unit determines that the magnetic ring overheating protection triggering condition is met, namely, the controlled switch is controlled to be closed to perform overheating protection, and safety accidents caused by overheating of the magnetic ring are avoided.
Further, in an embodiment, when it is detected that the temperature value is less than or equal to the third threshold, if the controlled switch is in the on state, the control unit may not perform processing and maintain the on state, or the control unit may further detect whether the power frequency circulating current is greater than the first threshold, and if the power frequency circulating current is greater than the first threshold, the controlled switch is controlled to be turned on. When the temperature value is detected to be less than or equal to the third threshold value, if the controlled switch is in a closed state, the control unit can directly control the controlled switch to be opened; or, when detecting that the temperature value is less than or equal to the third threshold, if the controlled switch is in the closed state, the control unit may further detect whether the temperature value is less than a fourth threshold (the fourth threshold is less than the third threshold), control the controlled switch to be turned on when detecting that the temperature value is less than the fourth threshold, and keep the controlled switch to be turned on when the temperature value is greater than or equal to the fourth threshold, so as to avoid the controlled switch from repeatedly acting; or, when it is detected that the temperature value is less than or equal to the third threshold, if the controlled switch is in the closed state, the control unit may further detect whether the power frequency circulating current is less than or equal to the first threshold, if so, control the controlled switch to be turned on, and if so, keep the controlled switch turned on.
Further, in an embodiment, after the step S20, the method further includes:
step A30, timing the continuous time of the inverter parallel system meeting the magnetic ring overheat protection condition from closing the controlled switch;
in this embodiment, the magnetic ring overheating protection system may further include an early warning unit. The early warning unit is used for controlled output of early warning prompts. The specific implementation manner of the warning unit is not limited herein, and may be implemented by a speaker, a vibration device, an indicator light, and the like.
After the controlled switch is closed, the control unit can start timing the duration of the state that the inverter parallel system meets the magnetic ring overheat protection condition.
And A40, controlling the early warning unit to output an early warning prompt when the timing duration is greater than the preset duration.
The control unit may detect whether the timed period is greater than a preset period. The preset time can be set according to needs, when the timing time is longer than the preset time, the state that the power frequency circulation is large or the state that the temperature value of the magnetic ring is high is indicated to last for a long time, and the magnetic ring may lose the function of suppressing the common mode noise when overheating protection is carried out.
Further, when the magnetic ring overheating protection triggering condition is set to be that the power frequency circulating current is larger than the first threshold, if the control unit detects that the power frequency circulating current is smaller than or equal to the first threshold when the timing duration does not reach the preset duration, the timing can be restarted when the power frequency circulating current is detected to be larger than the first threshold again in the closed state of the controlled switch. Further, in an embodiment, when the control unit starts the controlled switch when detecting that the power frequency circulating current is smaller than the second threshold, the control unit may start to time a duration of a state in which the power frequency circulating current is greater than or equal to the second threshold from closing the controlled switch, detect whether the timed duration is greater than a preset duration, and control the early warning unit to output the early warning prompt when the timed duration is greater than the preset duration.
EXAMPLE III
On the basis of the first embodiment and/or the second embodiment, the present embodiment further provides a magnetic ring overheat protection system for an inverter parallel system, which includes a current sampling unit, a control unit, a controlled switch, a dc power supply, and a winding disposed for a magnetic ring in the inverter parallel system;
the current sampling unit is used for collecting the power frequency circulation of the inverter parallel system and outputting the power frequency circulation to the control unit;
the controlled switch is controlled by the control unit and is used for switching on or switching off a direct current loop between the direct current power supply and the winding;
the current output by the direct current power supply enables the direct current bias added to the magnetic ring by the winding to be larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring;
the control unit is configured to execute the magnetic ring overheat protection method for the inverter parallel system in the first embodiment and/or the second embodiment.
The specific implementation of the magnetic ring overheat protection system in this embodiment may refer to the same or similar contents as those in the first and second embodiments, and may refer to the above description, and will not be described again in detail later.
Further, in an embodiment, the controlled switch is disposed outside the dc power supply and configured to cut off at least one connection line between the dc power supply and the winding. It should be noted that when the controlled switch is in the on state, a dc open circuit is formed between the dc power supply and the winding, and it should be ensured that the EMI frequency band is also in the high-impedance state (in practical application, the condition may be relaxed as long as CE (reduced interference) low frequency is ensuredSegment, e.g., below 5MHz, the impedance is above 3 times the magnetic loop impedance). If the winding has n turns, its impedance should be divided by n 2 And then still high resistance. When the controlled switch is arranged outside the direct-current power supply, the controlled switch is positioned between the differential mode capacitor and the winding in the direct-current power supply, and the controlled switch can be regarded as a high-resistance device and can ensure that the impedance is divided by n 2 And the magnetic ring is still high in resistance, so that the magnetic ring can normally provide a common mode noise suppression effect when the controlled switch is in an on state. In another embodiment, when the controlled switch is located inside the dc power supply, that is, between the differential mode capacitor and the winding in the dc power supply, a high resistance device may be disposed between the differential mode capacitor and the winding to ensure that the magnetic ring can normally provide the common mode noise suppression effect when the controlled switch is in the on state. For example, in one embodiment, an inductor may be disposed on one of the connection lines between the dc power source and the winding, or an inductor may be disposed on each of the two connection lines, or a differential mode inductor may be disposed on the two connection lines.
Example four
Corresponding to the three phases of the first embodiment, the second embodiment and the third embodiment, an embodiment of the present invention further provides a magnetic ring overheat protection device for an inverter parallel system, where the device is applied to a control unit in the magnetic ring overheat protection system, the magnetic ring overheat protection system further includes a current sampling unit, a controlled switch, a dc power supply and a winding configured for a magnetic ring in the inverter parallel system, and the device includes:
the receiving module is used for receiving the power frequency circulating current of the inverter parallel system collected by the current sampling unit;
and the control module is used for controlling the controlled switch to be closed when the inverter parallel system is detected to meet a preset magnetic ring overheat protection triggering condition so as to switch on a direct current loop between the direct current power supply and the winding, wherein the direct current bias added to the magnetic ring by the winding is larger than or equal to the sum of the power frequency loop current and the saturation current of the magnetic ring due to the current output by the direct current power supply.
Further, the apparatus further comprises:
and the first determining module is used for determining that the magnetic ring overheating protection triggering condition is met when the power frequency circulating current is detected to be larger than a first threshold value.
Further, the control module is further configured to:
and when the power frequency circulating current is smaller than a second threshold value, controlling the controlled switch to be switched on so as to disconnect a direct current loop between the direct current power supply and the winding, wherein the second threshold value is smaller than the first threshold value.
Further, the magnetic ring overheating protection system further comprises a temperature acquisition unit, and the receiving module is further configured to: receiving the temperature value of the magnetic ring acquired by the temperature acquisition unit;
the device further comprises:
and the second determination module is used for determining that the magnetic ring overheating protection triggering condition is met when the temperature value is detected to be greater than a third threshold value.
Further, the apparatus further comprises:
the calculation module is used for calculating the sum of the power frequency circulating current and the saturation current of the magnetic ring to obtain a target direct current bias when the inverter parallel system is detected to meet the magnetic ring overheat protection condition; calculating to obtain a target current value according to the target direct current bias and the number of turns of the winding;
the control module is further used for controlling the direct current power supply to output the direct current with the target current value.
Further, the magnetic ring overheat protection system further comprises an early warning unit, and the device further comprises:
the timing module is used for timing the duration of the state that the inverter parallel system meets the magnetic ring overheat protection condition from the closing of the controlled switch;
the control module is further used for controlling the early warning unit to output an early warning prompt when the timing duration is longer than the preset duration.
EXAMPLE five
Corresponding to the first embodiment, the second embodiment, the third embodiment and the fourth embodiment, the embodiment of the present invention further provides a magnetic ring overheat protection device for an inverter parallel system.
As shown in fig. 4, fig. 4 is a schematic device structure diagram of a hardware operating environment according to an embodiment of the present invention.
It should be noted that, the magnetic ring overheat protection device according to the embodiment of the present invention may be the control unit in the magnetic ring overheat protection system as described above.
As shown in fig. 4, the magnetic ring overheat protection apparatus may include: a processor 1001, e.g. a CPU, a network interface 1004, a user interface 1003, a memory 1005, a communication bus 1002. The communication bus 1002 is used to implement connection communication among these components. The user interface 1003 may include a Display screen (Display), an input unit such as a Keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface, a wireless interface. The network interface 1004 may optionally include a standard wired interface, a wireless interface (e.g., WI-FI interface). The memory 1005 may be a high-speed RAM memory or a non-volatile memory (e.g., a magnetic disk memory). The memory 1005 may alternatively be a storage device separate from the processor 1001.
Those skilled in the art will appreciate that the configuration of the device shown in fig. 4 does not constitute a limitation of the magnetic ring overheat protection device, and may include more or fewer components than those shown, or some components in combination, or a different arrangement of components.
As shown in fig. 4, the memory 1005, which is a kind of computer storage medium, may include therein an operating system, a network communication module, a user interface module, and a magnetic loop overheat protection program. The operating system is a program for managing and controlling hardware and software resources of the equipment and supports the operation of a magnetic ring overheating protection program and other software or programs. In the device shown in fig. 4, the user interface 1003 is mainly used for data communication with the client; the network interface 1004 is mainly used for establishing communication connection with a server; and the processor 1001 may be configured to call the magnetic ring overheating protection program stored in the memory 1005, and perform the following operations:
receiving the power frequency circulation of the inverter parallel system collected by the current sampling unit;
and when the inverter parallel system is detected to meet a preset magnetic ring overheat protection triggering condition, controlling the controlled switch to be closed so as to switch on a direct current loop between the direct current power supply and the winding, wherein the current output by the direct current power supply enables the direct current bias added to the magnetic ring by the winding to be larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring.
Further, before the operation of controlling the closing of the controlled switch, the processor 1001 may be further configured to invoke a magnetic ring overheat protection program stored in the memory 1005, and perform the following operations:
and when the power frequency circulating current is detected to be larger than a first threshold value, determining that the magnetic ring overheating protection triggering condition is met.
Further, after the operation of receiving the power frequency circulating current of the inverter parallel system collected by the current sampling unit, the processor 1001 may be further configured to call a magnetic loop overheat protection program stored in the memory 1005, and execute the following operations:
and when the power frequency circulating current is smaller than a second threshold value, controlling the controlled switch to be switched on so as to disconnect a direct current loop between the direct current power supply and the winding, wherein the second threshold value is smaller than the first threshold value.
Further, the magnetic ring overheat protection system further includes a temperature acquisition unit, and before the operation of controlling the controlled switch to be closed, the processor 1001 may be further configured to call a magnetic ring overheat protection program stored in the memory 1005, and perform the following operations:
receiving the temperature value of the magnetic ring acquired by the temperature acquisition unit;
and when the temperature value is detected to be larger than a third threshold value, determining that the magnetic ring overheating protection triggering condition is met.
Further, after the operation of receiving the power frequency circulating current of the inverter parallel system collected by the current sampling unit, the processor 1001 may be further configured to call a magnetic loop overheat protection program stored in the memory 1005, and execute the following operations:
when the inverter parallel system is detected to meet the magnetic ring overheating protection condition, calculating the sum of the power frequency circulating current and the saturation current of the magnetic ring to obtain target direct current bias;
calculating to obtain a target current value according to the target direct current bias and the number of turns of the winding;
and controlling the direct current power supply to output direct current with the target current value.
Further, the magnetic ring overheating protection system further includes an early warning unit, and after the operation of controlling the controlled switch to be closed, the processor 1001 may be further configured to call a magnetic ring overheating protection program stored in the memory 1005 to perform the following operations:
timing the duration of the state that the power frequency circulating current is larger than the first threshold value from the time when the controlled switch is closed;
and when the timing duration is greater than the preset duration, controlling the early warning unit to output an early warning prompt.
EXAMPLE six
Corresponding to the first embodiment, the second embodiment, the third embodiment, the fourth embodiment and the fifth embodiment, the embodiment of the present invention further provides a computer-readable storage medium, where a magnetic ring overheat protection program is stored on the storage medium, and the magnetic ring overheat protection program, when executed by a processor, implements the steps of the magnetic ring overheat protection method as described above.
The embodiments of the magnetic ring overheat protection device, the magnetic ring overheat protection apparatus, and the computer readable storage medium of the present invention can refer to the embodiments of the magnetic ring overheat protection method of the present invention, and are not described herein again.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal device (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (12)
1. A magnetic ring overheating protection method of an inverter parallel system is applied to a control unit in the magnetic ring overheating protection system, the magnetic ring overheating protection system further comprises a current sampling unit, a controlled switch, a direct current power supply and a winding set for a magnetic ring in the inverter parallel system, and the method comprises the following steps:
receiving the power frequency circulation of the inverter parallel system collected by the current sampling unit;
and when the inverter parallel system is detected to meet a preset magnetic ring overheat protection triggering condition, controlling the controlled switch to be closed so as to switch on a direct current loop between the direct current power supply and the winding, wherein the current output by the direct current power supply enables the direct current bias added to the magnetic ring by the winding to be larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring.
2. A magnetic loop overheat protection method for an inverter parallel system as claimed in claim 1, wherein said step of controlling said controlled switch to be closed further comprises:
and when the power frequency circulating current is detected to be larger than a first threshold value, determining that the magnetic ring overheating protection triggering condition is met.
3. The method for protecting a magnetic ring of an inverter parallel system from overheating as claimed in claim 2, wherein after the step of receiving the power frequency circulating current of the inverter parallel system collected by the current sampling unit, the method further comprises:
and when the power frequency circulating current is smaller than a second threshold value, controlling the controlled switch to be switched on so as to disconnect a direct current loop between the direct current power supply and the winding, wherein the second threshold value is smaller than the first threshold value.
4. A magnetic loop overheat protection method for an inverter parallel system as claimed in claim 1, wherein said magnetic loop overheat protection system further comprises a temperature acquisition unit, and before said step of controlling said controlled switch to be closed, said method further comprises:
receiving the temperature value of the magnetic ring acquired by the temperature acquisition unit;
and when the temperature value is detected to be larger than a third threshold value, determining that the magnetic ring overheating protection triggering condition is met.
5. The method for protecting a magnetic ring of an inverter parallel system from overheating as claimed in claim 1, wherein after the step of receiving the power frequency circulating current of the inverter parallel system collected by the current sampling unit, the method further comprises:
when the inverter parallel system is detected to meet the magnetic ring overheat protection condition, calculating the sum of the power frequency circulating current and the saturation current of the magnetic ring to obtain target direct current bias;
calculating to obtain a target current value according to the target direct current bias and the number of turns of the winding;
and controlling the direct current power supply to output direct current with the target current value.
6. The magnetic loop overheat protection method for the inverter parallel system according to any one of claims 1 to 5, wherein the magnetic loop overheat protection system further comprises an early warning unit, and after the step of controlling the controlled switches to be closed, the method further comprises:
timing the duration of the state duration that the inverter parallel system meets the magnetic ring overheat protection condition from the closing of the controlled switch;
and when the timing duration is longer than the preset duration, controlling the early warning unit to output an early warning prompt.
7. A magnetic ring overheat protection system of an inverter parallel system is characterized by comprising a current sampling unit, a control unit, a controlled switch, a direct current power supply and a winding which is arranged aiming at a magnetic ring in the inverter parallel system;
the current sampling unit is used for collecting the power frequency circulation of the inverter parallel system and outputting the power frequency circulation to the control unit;
the controlled switch is controlled by the control unit and is used for switching on or switching off a direct current loop between the direct current power supply and the winding;
the current output by the direct current power supply enables the direct current bias added to the magnetic ring by the winding to be larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring;
the control unit is used for executing the magnetic ring overheating protection method of the inverter parallel system as claimed in any one of claims 1 to 6.
8. A magnetic loop overheat protection system for an inverter parallel system as claimed in claim 7 wherein said controlled switch is provided outside said dc power supply for disconnecting at least one connection line between said dc power supply and said winding.
9. A magnetic ring overheat protection system for an inverter parallel system as claimed in claim 7, wherein said controlled switch is disposed inside said dc power supply, and an inductor is disposed on one of the connection lines between said dc power supply and said winding, or an inductor is disposed on each of the two connection lines, or a differential mode inductor is disposed on each of the two connection lines.
10. A magnetic ring overheat protection device of an inverter parallel system is characterized in that the device is applied to a control unit in the magnetic ring overheat protection system, the magnetic ring overheat protection system further comprises a current sampling unit, a controlled switch, a direct current power supply and a winding arranged aiming at a magnetic ring in the inverter parallel system, and the device comprises:
the receiving module is used for receiving the power frequency circulating current of the inverter parallel system collected by the current sampling unit;
and the control module is used for controlling the controlled switch to be closed when the inverter parallel system is detected to meet a preset magnetic ring overheat protection triggering condition, so as to switch on a direct current loop between the direct current power supply and the winding, wherein the current output by the direct current power supply enables the direct current offset added to the magnetic ring by the winding to be larger than or equal to the sum of the power frequency circulating current and the saturation current of the magnetic ring.
11. A magnetic loop overheat protection apparatus of an inverter parallel system, characterized by comprising: a memory, a processor, and a magnetic ring overheat protection program stored on the memory and executable on the processor, the magnetic ring overheat protection program when executed by the processor implementing the steps of the magnetic ring overheat protection method as claimed in any one of claims 1 to 6.
12. A computer-readable storage medium, characterized in that a magnetic ring overheat protection program is stored on the computer-readable storage medium, which when executed by a processor implements the steps of the magnetic ring overheat protection method according to any one of claims 1 to 6.
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| CN202211123740.5A CN115459571A (en) | 2022-09-15 | 2022-09-15 | Magnetic ring overheating protection method, system, device, equipment and medium |
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| CN202211123740.5A CN115459571A (en) | 2022-09-15 | 2022-09-15 | Magnetic ring overheating protection method, system, device, equipment and medium |
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