Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a non-contact three-phase current detection system which is simpler in structure, can accurately and stably sample the three-phase current and can be used for checking and diagnosing, and is better in performance.
In order to achieve the above purposes, the technical scheme adopted by the invention is as follows:
a non-contact, three-phase current sensing system for sensing three-phase currents of an inverter control system of an electric drive system, comprising:
the inductive loop current sampling unit is used for acquiring the three-phase current of an inverter control system of the electric drive system in the inductive loop;
the magnetic induction sampling unit is a magnetic induction chip and is matched with the current sampling unit, and the magnetic induction sampling unit is used for inducing the three-phase current collected by the induced loop current sampling unit;
the current shaping unit is connected with the magnetic induction sampling unit and is used for shaping the three-phase current induced by the magnetic induction sampling unit;
the signal processing unit is connected with the current shaping unit and is used for carrying out analog-to-digital conversion and filtering processing on the three-phase current after shaping processing;
and the current monitoring unit and the signal processing unit are used for verifying the three-phase current processed by the signal processing unit according to a preset current error and outputting an abnormal mark when the three-phase current does not meet the preset current error.
On the basis of the technical scheme, the current sampling unit comprises three induced loop current sampling circuit modules, and the three induced loop current sampling circuit modules respectively and correspondingly acquire the U-phase current, the V-phase current and the W-phase current of the inverter control system of the electric drive system.
On the basis of the technical scheme, the current shaping unit comprises three magnetic induction current modules, and the three magnetic induction current modules are respectively matched with one induced loop current sampling circuit module.
On the basis of the technical scheme, the current shaping unit comprises three current shaping modules, and the three current shaping modules are respectively and correspondingly connected with one magnetic induction current module.
On the basis of the technical scheme, the signal processing unit comprises three signal processing modules, the input ends of the three signal processing modules are respectively and correspondingly connected with the output end of one current shaping module, and the output ends of all the signal processing modules are connected with the current monitoring module.
On the basis of the technical scheme, the signal processing module comprises an analog-to-digital conversion module and a digital filtering module which are sequentially connected.
On the basis of the technical scheme, the current monitoring unit is further used for obtaining the verified three-phase current according to the preset current error and the input three-phase current and outputting the verified three-phase current.
On the basis of the technical scheme, the preset current error is calculated according to a kirchhoff algorithm, and the current error of the same phase of the three-phase current is obtained.
On the basis of the technical scheme, the sampling precision of the three-phase current detection system is within 5%.
On the basis of the technical scheme, the induced loop current sampling unit is a copper bar, and the copper bar is matched with the magnetic induction chip.
Compared with the prior art, the invention has the advantages that: according to the non-contact three-phase current detection system, on one hand, the non-contact magnetic induction chip is adopted, the non-contact magnetic induction chip is not required to be connected with the three-phase current of the inverter control system of the electric drive system through a wire harness, the structure is simpler, on the other hand, accurate and stable sampling and checking diagnosis of the three-phase current can be realized, and the performance is better.
Detailed Description
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. It is to be noted that all the figures are exemplary representations. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
The present invention will be described in further detail below with reference to specific embodiments and with reference to the attached drawings.
Referring to fig. 1, an embodiment of the present invention provides a non-contact three-phase current detection system, which is used for detecting three-phase currents of an inverter control system of an electric drive system, and includes an induced loop current sampling unit, a magnetic induction sampling unit, a current shaping unit, a signal processing unit, and a current monitoring unit.
The induced loop current sampling unit is used for acquiring the three-phase current of an inverter control system of the electric drive system in the induced loop.
The magnetic induction sampling unit is a magnetic induction chip, and is matched with the current sampling unit to be arranged, and the magnetic induction sampling unit is used for inducing the three-phase current collected by the induction loop current sampling unit.
And the current shaping unit is connected with the magnetic induction sampling unit and is used for shaping the three-phase current sensed by the magnetic induction sampling unit.
And the signal processing unit is connected with the current shaping unit and is used for carrying out analog-to-digital conversion and filtering processing on the three-phase current after shaping processing.
And the current monitoring unit and the signal processing unit are used for verifying the three-phase current processed by the signal processing unit according to a preset current error and outputting an abnormal mark when the three-phase current does not meet the preset current error.
In the embodiment of the invention, the non-contact three-phase current detection system further comprises a power supply module which is connected with the magnetic induction sampling unit, the current shaping unit, the signal processing unit and the current monitoring unit and is used for supplying power to the magnetic induction sampling unit, the current shaping unit, the signal processing unit and the current monitoring unit.
The working principle of the non-contact three-phase current detection system provided by the embodiment of the invention is as follows:
the method comprises the steps of firstly collecting three-phase current of an inverter control system of an electric drive system in an induced loop through an induced loop current sampling unit, then inducing the three-phase current of the inverter control system of the electric drive system through a non-contact magnetic induction chip, then sequentially shaping, analog-to-digital conversion and filtering the collected three-phase current, checking the processed three-phase current according to a preset current error, outputting an abnormal mark when the three-phase current does not meet the preset current error, and outputting a normal mark when the three-phase current meets the preset current error, thereby accurately and stably sampling the three-phase current of the inverter control system of the electric drive system and checking and diagnosing the three-phase current.
On one hand, the non-contact three-phase current detection system in the embodiment of the invention adopts the non-contact magnetic induction chip, does not need to be connected with the three-phase current of the inverter control system of the electric drive system through a wire harness, has simpler structure, and on the other hand, can realize accurate and stable sampling, checking and diagnosis of the three-phase current, and has better performance.
As shown in fig. 2, as a better implementation manner, in an embodiment of the present invention, the current sampling unit includes three induced loop current sampling circuit modules, and the three induced loop current sampling circuit modules respectively and correspondingly acquire a U-phase current, a V-phase current, and a W-phase current of an inverter control system of the electric drive system.
The three induced loop current sampling circuit modules are respectively recorded as a U-phase induced loop current sampling circuit module, a V-phase induced loop current sampling circuit module and a W-phase induced loop current sampling circuit module, the U-phase induced loop current sampling circuit module is used for acquiring the U-phase current of an inverter control system of the electric drive system, the V-phase induced loop current sampling circuit module is used for acquiring the V-phase current of the inverter control system of the electric drive system, and the W-phase induced loop current sampling circuit module is used for acquiring the W-phase current of the inverter control system of the electric drive system.
Correspondingly, in the embodiment of the present invention, the current shaping unit includes three magnetic induction current modules, and the three magnetic induction current modules are respectively matched with one induced loop current sampling circuit module.
The three magnetic induction current modules are respectively recorded as a U-phase magnetic induction current module, a V-phase magnetic induction current module and a W-phase magnetic induction current module, the U-phase magnetic induction current module is connected with the U-phase induced loop current sampling circuit module, the V-phase magnetic induction current module is connected with the V-phase induced loop current sampling circuit module, and the W-phase magnetic induction current module is connected with the W-phase induced loop current sampling circuit module.
Correspondingly, in the embodiment of the present invention, the current shaping unit includes three current shaping modules, and the three current shaping modules are respectively and correspondingly connected to one magnetic induction current module.
The three current shaping modules are respectively recorded as a U-phase current shaping module, a V-phase current shaping module and a W-phase current shaping module, the U-phase current shaping module is connected with the U-phase magnetic induction current module, the V-phase current shaping module is connected with the V-phase magnetic induction current module, and the W-phase current shaping module is connected with the W-phase magnetic induction current module.
Correspondingly, in the embodiment of the present invention, the signal processing unit includes three signal processing modules, input ends of the three signal processing modules are respectively and correspondingly connected to an output end of one current shaping module, and output ends of all the signal processing modules are connected to the current monitoring module.
More specifically, in the embodiment of the present invention, the signal processing module includes an analog-to-digital conversion module and a digital filtering module, which are connected in sequence. The analog-to-digital conversion module can adopt a conventional analog-to-digital converter, and the digital filtering module can adopt a conventional filter.
The three analog-to-digital conversion modules are respectively recorded as a U-phase analog-to-digital conversion module, a V-phase analog-to-digital conversion module and a W-phase analog-to-digital conversion module, the U-phase analog-to-digital conversion module is connected with the U-phase current shaping module, the V-phase analog-to-digital conversion module is connected with the V-phase current shaping module, and the W-phase analog-to-digital conversion module is connected with the W-phase current shaping module.
The three digital filtering modules are respectively recorded as a U-phase digital filtering module, a V-phase digital filtering module and a W-phase digital filtering module, the U-phase digital filtering module is connected with the U-phase analog-to-digital conversion module, the V-phase digital filtering module is connected with the V-phase analog-to-digital conversion module, the W-phase digital filtering module is connected with the W-phase analog-to-digital conversion module, and the output ends of the U-phase digital filtering module, the V-phase digital filtering module and the W-phase digital filtering module are connected with the current monitoring module.
As a better implementation manner, in an embodiment of the present invention, the current monitoring unit is further configured to obtain a verified three-phase current according to a preset current error and the input three-phase current, and output the verified three-phase current.
Specifically, in the embodiment of the present invention, the preset current error is a current error of the same phase of the three-phase current calculated according to kirchhoff algorithm. The sampling precision of the three-phase current detection system is within 5%.
Preferably, in the embodiment of the present invention, the induced loop current sampling unit is a copper bar, and the copper bar is matched with the magnetic induction chip.
The present invention is not limited to the above-described embodiments, and it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and such modifications and improvements are also considered to be within the scope of the present invention. Those not described in detail in this specification are within the skill of the art.