Disclosure of Invention
In view of the above, an object of the present application is to provide a method, an apparatus, a device, and a computer readable storage medium for detecting a fault of an input zero line of an uninterruptible power supply, so as to effectively improve detection accuracy and reduce device cost. The specific scheme is as follows:
in a first aspect, the application discloses a method for detecting a fault of zero line loss in input of an uninterruptible power supply, which includes:
acquiring positive bus voltage and negative bus voltage of a rectifier of the uninterruptible power supply;
judging whether the positive bus voltage and the negative bus voltage change reversely;
and if so, judging that the uninterrupted power supply has a fault of zero line input loss.
Optionally, the determining whether the magnitudes of the positive bus voltage and the negative bus voltage change reversely includes:
calculating the difference of the positive bus voltage and the negative bus voltage;
calculating an integral quantity of the difference;
judging whether the integral quantity changes monotonously or not;
and if so, determining that the positive bus voltage and the negative bus voltage are reversely changed.
Optionally, the calculating the integral quantity of the difference value includes:
and inputting the difference value into a controller of the uninterruptible power supply so as to obtain an integral quantity of the difference value calculated by a bus unbalance ring in the controller.
Optionally, the determining whether the magnitudes of the positive bus voltage and the negative bus voltage change reversely includes:
calculating a first variation of the positive bus voltage and a second variation of the negative bus voltage in a unit time;
judging whether the first variable quantity and the second variable quantity have positive and negative opposite signs or not;
and if so, determining that the positive bus voltage and the negative bus voltage are reversely changed.
Optionally, after determining that the magnitudes of the positive bus voltage and the negative bus voltage change reversely, the method further includes:
judging whether the duration time of the condition that the sizes of the positive bus voltage and the negative bus voltage are reversely changed reaches a preset duration time or not;
and if so, judging that the uninterrupted power supply has a fault of zero line input loss.
Optionally, the preset time duration is 20 ms.
Optionally, after the determining that the uninterruptible power supply has the fault of inputting the zero line, the method further includes:
and generating a fault alarm signal of inputting the zero line so as to prompt a user.
In a second aspect, the present application discloses a detection apparatus for detecting zero line fault is fallen in input of an uninterruptible power supply, including:
the acquisition module is used for acquiring the positive bus voltage and the negative bus voltage of the rectifier of the uninterruptible power supply;
the judging module is used for judging whether the positive bus voltage and the negative bus voltage change reversely; and if so, judging that the uninterrupted power supply has a fault of zero line input loss.
In a third aspect, the present application discloses a device for detecting zero line fault in input of an uninterruptible power supply, including:
the voltage sensor is used for detecting the positive bus voltage and the negative bus voltage of the rectifier of the uninterruptible power supply and sending the positive bus voltage and the negative bus voltage to the data processor;
the data processor is used for realizing the steps of the method for detecting the fault of the zero line input of any uninterrupted power supply.
In a fourth aspect, the present application discloses a computer-readable storage medium, on which a computer program is stored, the computer program, when being executed by a processor, is configured to implement the steps of the method for detecting an input-out zero line fault of any one of the uninterruptible power supplies described above.
The method comprises the steps of obtaining positive bus voltage and negative bus voltage of a rectifier of the uninterruptible power supply; judging whether the positive bus voltage and the negative bus voltage change reversely; if yes, judging that the uninterrupted power supply has a fault of zero line input. Therefore, a hardware detection circuit is not required to be introduced, the detection result of zero line fault can be obtained by analyzing the size change conditions of the positive bus voltage and the negative bus voltage of the rectifier, the equipment cost is reduced, a new fault point is avoided being introduced, the accuracy of the detection result is improved, and the detection method is convenient and efficient.
Detailed Description
The core of the application is to provide a method, a device, equipment and a computer readable storage medium for detecting zero line fault input of an uninterruptible power supply, so as to effectively improve detection precision and reduce equipment cost.
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
As shown in fig. 1, in a normal condition, the input end of the zero line of the rectifier is connected to the zero line of the commercial power, i.e. N point in fig. 1, is a reference point for stabilizing the electric potential, and at this time, the three-phase symmetric alternating current is input to the rectifier from the commercial power. And once the input zero line of the rectifier is disconnected, the potential of the N point is not stable any more. For the purpose of controlling the balance of the bus midpoint (i.e. point O in fig. 1), the current flowing from the PFC to the bus midpoint in the UPS is not zero, i.e. zero-sequence current is generated, a current loop is formed between point O and point N, and the potential of point N is shifted. And with the shift of the potential of the N point, the potential of the midpoint of the bus is also in an unstable state, so that the bus is out of control and unbalanced.
In order to detect the phenomenon, the embodiment of the application discloses a method for detecting a fault of an input zero line of an uninterruptible power supply. Compared with a hardware detection circuit in the prior art, the method disclosed by the application can be realized by using control devices such as a single chip microcomputer and a CPLD, and belongs to a software detection method. Referring to fig. 2, the method mainly includes the following steps:
s1: and acquiring positive bus voltage BusP and negative bus voltage BusN of a rectifier of the uninterruptible power supply.
Specifically, whether the fault of the input zero line occurs is judged by judging whether the positive bus voltage BusP and the negative bus voltage BusN are reversely changed. As described above, when the input neutral line of the rectifier is disconnected, the potential at the N point is shifted, and the potential at the midpoint of the bus is also shifted, so that the magnitudes of the positive bus voltage BusP and the negative bus voltage BusN are changed. Because the voltage difference between the positive bus and the negative bus is kept constant, the deviation of the midpoint potential of the bus inevitably causes the positive bus voltage BusP and the negative bus voltage BusN to change in opposite directions, namely one increases and the other decreases, so that the deviation can be used as a basis for judging the occurrence of the fault of the input zero line.
The positive bus voltage BusP, i.e., the potential difference between the positive bus and the bus midpoint, and the negative bus voltage BusN, i.e., the potential difference between the bus midpoint and the negative bus, can be detected by the relevant voltage sensors.
S2: judging whether the positive bus voltage BusP and the negative bus voltage BusN are reversely changed or not; if yes, the process proceeds to S3.
And when the positive bus voltage BusP and the negative bus voltage BusN are reversely changed, the input zero line can be judged to be disconnected.
S3: and judging that the uninterrupted power supply has a fault of zero line input loss.
The method comprises the steps of obtaining positive bus voltage and negative bus voltage of a rectifier of the uninterruptible power supply; judging whether the positive bus voltage and the negative bus voltage change reversely; if yes, judging that the uninterrupted power supply has a fault of zero line input. Therefore, a hardware detection circuit is not required to be introduced, the detection result of zero line fault can be obtained by analyzing the size change conditions of the positive bus voltage and the negative bus voltage of the rectifier, the equipment cost is reduced, a new fault point is avoided being introduced, the accuracy of the detection result is improved, and the detection method is convenient and efficient.
Referring to fig. 3, fig. 3 is a flowchart illustrating a method for determining whether the magnitudes of the positive bus voltage and the negative bus voltage are reversely changed according to the present disclosure.
On the basis of the above content, as a specific embodiment, the method for detecting a fault of zero line drop in input of an uninterruptible power supply, where determining whether the magnitudes of the positive bus voltage BusP and the negative bus voltage BusN are reversely changed includes:
s31: the difference in magnitude of the positive bus voltage BusP and the negative bus voltage BusN is calculated.
S32: an integral amount of the difference is calculated.
S33: judging whether the integral quantity changes monotonously or not; if yes, the process proceeds to S34.
S34: and judging that the positive bus voltage BusP and the negative bus voltage BusN are reversely changed.
Specifically, this embodiment provides a specific scheme for determining whether the magnitudes of the positive bus voltage BusP and the negative bus voltage BusN change in opposite directions, that is, the determination is performed according to the change of the integral of the difference between the positive bus voltage BusP and the negative bus voltage BusN: if the integral quantity of the difference value is monotonically increased or monotonically decreased, the positive bus voltage BusP and the negative bus voltage BusN are changed in the reverse direction, and therefore the disconnection of the input zero line can be judged.
On this basis, preferably, the calculating the integral quantity of the difference value includes: and inputting the difference value into a controller of the uninterruptible power supply so as to obtain an integral quantity of the difference value calculated by a bus unbalance ring in the controller.
Generally, when the controller of the ups performs the bus balance control, the integral quantity of the difference value BusN between the positive bus voltage BusP and the negative bus voltage is used, so that the calculation result in the controller of the ups can be directly used in the detection method provided by the present application. Specifically, please refer to fig. 4, in which fig. 4 is a diagram illustrating an exemplary control structure of a controller of an ups disclosed in the present application.
As shown in fig. 4, the difference between the positive bus voltage BusP and the negative bus voltage BusN is input to a PI controller, i.e., a proportional-integral controller, and the output PI control quantity is I0 — ref, which includes a proportional control quantity and an integral control quantity, i.e., an integral quantity of the difference between the positive bus voltage BusP and the negative bus voltage BusN, which is required in this application. Therefore, in the embodiment, the zero line fault can be judged by directly utilizing the intermediate calculation result of the uninterruptible power supply controller in the prior art, and the calculation process is further simplified.
In fig. 4, Ubus _ ref and Ubus _ fdb are given and feedback quantities of the difference values of the positive and negative bus voltages input to the dq control loop, Id _ fdb and Iq _ fdb are feedback quantities of the d-axis current and the q-axis current, respectively, and I0_ fdb is a feedback quantity of the zero-sequence current.
Referring to fig. 5, fig. 5 is a flowchart of another method for determining whether the magnitudes of the positive bus voltage and the negative bus voltage are reversely changed, which includes the following steps:
s51: and calculating a first variation of the positive bus voltage BusP and a second variation of the negative bus voltage BusN in unit time.
S52: and judging whether the first variable quantity and the second variable quantity have positive and negative opposite signs.
S53: if yes, the positive bus voltage BusP and the negative bus voltage BusN are judged to be reversely changed.
In this embodiment, the determination may be intuitively made according to whether the variation amounts of the positive bus voltage BusP and the negative bus voltage BusN are different in sign. The unit time may be set to a shorter time period, and the setting may be selected by a person skilled in the art, which is not limited in this application.
On the basis of the above content, the method for detecting a fault of zero line input of an uninterruptible power supply provided by the present application, as a specific embodiment, after determining that the magnitudes of the positive bus voltage and the negative bus voltage are reversely changed, further includes: judging whether the duration time of the condition that the positive bus voltage BusP and the negative bus voltage BusN are reversely changed reaches a preset duration time or not; if yes, judging that the uninterrupted power supply has a fault of zero line input.
Specifically, in order to further improve the accuracy of the detection result and avoid false detection caused by bad data at some time, in this embodiment, the duration of the reverse change condition of the positive and negative bus voltages can be considered, that is, it is determined that the zero line fault is input only after the condition continues for a certain duration.
Wherein, preferably, the preset time is 20 ms. Since the mains frequency is 50Hz, 20ms is one mains cycle, and thus it may be preferable to set the preset duration to 20 ms.
In addition, on the basis of the above content, the method for detecting the zero line fault input to the uninterruptible power supply further includes, after determining that the zero line fault input to the uninterruptible power supply occurs: and generating a fault alarm signal of inputting the zero line so as to prompt a user.
Specifically, the alarm may be given by using an indicator light, a buzzer, and the like, and the technical personnel in the field may select and set the alarm by themselves, which is not limited in the present application.
The following introduces a device for detecting a fault of zero line input of an uninterruptible power supply according to an embodiment of the present application, and the device for detecting a fault of zero line input of an uninterruptible power supply described below and the method for detecting a fault of zero line input of an uninterruptible power supply described above may be referred to in correspondence.
Fig. 6 is a schematic structural diagram of a device for detecting a zero line fault input to an uninterruptible power supply according to an embodiment of the present application, and referring to fig. 6, the device for detecting a zero line fault input to an uninterruptible power supply may include:
an obtaining module 61, configured to obtain a positive bus voltage and a negative bus voltage of a rectifier of the uninterruptible power supply;
the judging module 62 is configured to judge whether the magnitudes of the positive bus voltage and the negative bus voltage change in the opposite direction; if yes, judging that the uninterrupted power supply has a fault of zero line input.
The method comprises the steps of obtaining positive bus voltage and negative bus voltage of a rectifier of the uninterruptible power supply; judging whether the positive bus voltage and the negative bus voltage change reversely; if yes, judging that the uninterrupted power supply has a fault of zero line input. Therefore, a hardware detection circuit is not required to be introduced, the detection result of zero line fault can be obtained by analyzing the size change conditions of the positive bus voltage and the negative bus voltage of the rectifier, the equipment cost is reduced, a new fault point is avoided being introduced, the accuracy of the detection result is improved, and the detection method is convenient and efficient.
In some specific embodiments, the determining module 62 is specifically configured to: calculating the difference value of the positive bus voltage and the negative bus voltage; calculating an integral quantity of the difference; judging whether the integral quantity changes monotonously or not; if yes, the positive bus voltage and the negative bus voltage are judged to be reversely changed.
In some specific embodiments, the determining module 62 is specifically configured to: and inputting the difference value into a controller of the uninterruptible power supply so as to obtain an integral quantity of the difference value calculated by a bus unbalance ring in the controller.
In some specific embodiments, the determining module 62 is specifically configured to: calculating a first variation of the positive bus voltage and a second variation of the negative bus voltage in unit time; judging whether the first variable quantity and the second variable quantity have positive and negative opposite signs or not; if yes, the positive bus voltage and the negative bus voltage are judged to be reversely changed.
In some specific embodiments, the determining module 62 is further configured to: judging whether the duration time of the condition that the magnitudes of the positive bus voltage and the negative bus voltage are reversely changed reaches a preset duration time or not; if yes, judging that the uninterrupted power supply has a fault of zero line input.
In some specific embodiments, the preset duration is 20 ms.
In some specific embodiments, the uninterruptible power supply further comprises an alarm module, configured to generate a fault alarm signal for inputting the zero line after determining that the uninterruptible power supply has the fault of inputting the zero line so as to prompt a user.
Further, the embodiment of the present application further discloses a detection apparatus for detecting a fault that a zero line is dropped in input of an uninterruptible power supply, and as shown in fig. 7, the detection apparatus for detecting a fault that a zero line is dropped in input of an uninterruptible power supply includes:
the voltage sensor 71 is used for detecting the positive bus voltage and the negative bus voltage of the rectifier of the uninterruptible power supply and sending the positive bus voltage and the negative bus voltage to the data processor;
a data processor 72 for implementing the steps of the method for detecting an input-out zero line fault of any one of the above-described uninterruptible power supplies.
Further, an embodiment of the present application also discloses a computer readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements the following steps:
in some specific embodiments, when executed by a processor, the computer program stored in the computer-readable storage medium may implement the steps of any of the methods for detecting an input-zero-line fault of an uninterruptible power supply described above.
The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, 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 an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The foregoing has described the present application in detail, and the principles and implementations of the present application have been described herein using specific examples, which are provided only to facilitate understanding of the methods and core concepts of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.