Unlock instant, AI-driven research and patent intelligence for your innovation.
A current-based open-circuit fault detection method for three-phase inverters
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A technology for three-phase inverters and open-circuit faults, which is applied in the direction of measuring electrical variables, instruments, and measuring electricity. It can solve the problems of increased calculation, more calculations, and slow detection. The effect of false positives
Inactive Publication Date: 2017-06-16
UNIV OF ELECTRONICS SCI & TECH OF CHINA
View PDF6 Cites 0 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
[0017] (1) It can only detect and locate the open-circuit fault of a single switching tube of the inverter, but cannot detect the open-circuit fault of multiple switching tubes at the same time. To detect multi-tube open-circuit faults, additional detection variables must be added, which makes the method complicated , more calculations;
[0018] (2) The three-phase expected current i used n * Two coordinate transformations are required to obtain it, which will increase the amount of calculation and make the detection slower
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Image
Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
Click on the blue label to locate the original text in one second.
Reading with bidirectional positioning of images and text.
Smart Image
Examples
Experimental program
Comparison scheme
Effect test
Embodiment
[0044] figure 2 It is a flowchart of the current-based three-phase inverter open-circuit fault detection method of the present invention.
[0045] In this embodiment, as figure 2 As shown, the current-based three-phase inverter open-circuit fault detection method of the present invention includes the following steps:
[0046] (1) Get the motor three-phase current i from the motor drive control system n (n=a, b, c);
[0047] (2) According to the three-phase current of the motor i n Calculate each phase detection variable d n (n=a, b, c)
[0048]
[0049] among them,
[0050]
[0051]
[0052] among them, n > Is the three-phase current i n Period average, n |> Is the three-phase current i n The period average of the absolute value of, w represents the angular frequency of the stator current of the motor; under normal circumstances, the three-phase current i n Period average n > ≈0, so d n ≈1;
[0053] In this embodiment, as figure 2 As shown, the present invention only needs to collect ...
example
[0063] In this embodiment, it is assumed that the three-phase AC asynchronous motor has a rated power of 1.1kW, a rated speed of 1390rpm, a rated torque of 7.6Nm, a rated current of 2.89A, and a detection variable threshold k 1 = -0.3, k 2 = 0.3, k 3 = 1.8, k 4 = 3.3.
[0064] image 3 Is the motor three-phase current and the detection variable d n Waveform graph.
[0065] In this embodiment, as image 3 As shown, when the motor is at rated speed and 50% rated load, at time t=2s, T1 has an open circuit fault; at t=2.2s, T1 and T2 both have open circuit faults; at t=2.4s, T1 T2 and T3 have open circuit faults at the same time; the details are as follows:
[0066] When t=1.8~2s:
[0067] Such as image 3 (a) shows that the motor phase current i a Is a symmetrical sine wave, then d a ≈1, fault indication D a =0; such as image 3 (b) shows that the motor phase current i b Is a symmetrical sine wave, then d b ≈1, fault indication D b =0; such as image 3 (c) shows that the motor phase curr...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More
PUM
Login to View More
Abstract
The invention discloses a current-based three-phase inverter open-circuit fault detection method. First, the three-phase current i of the motor is obtained from the motor drivecontrol system. n , and then perform weighting processing on the periodic average value of the three-phase current and the periodic average value of the absolute value, and perform normalization processing to obtain the detection variable d n , then will detect the variable d n with the preset threshold k i Compare and get the fault indication D of the three-phase inverter n , and then according to the fault indication D n Locate the inverter switch tube that has an open-circuit fault in the fault location table. This method is simple and easy to implement and suitable for integration into control systems.
Description
Technical field [0001] The invention belongs to the technical field of three-phase inverter fault detection, and more specifically, relates to a current-based three-phase inverter open-circuit fault detection method. Background technique [0002] With the widespread use of motor speed control systems in industrial applications, the safety of speed control systems has increasingly become the focus of attention. As an important part of the speed control system, the motor drivesystem's reliability is essential to the safe operation of the speed control system. However, the reliability of the motor drivesystem is mainly affected by the power devices of the three-phase inverter. In order to improve the safety of the speed control system, the fault of the three-phase inverter is effectively detected and located in real time, and corresponding fault-tolerant control is applied. It seems indispensable. [0003] The power device failure of a three-phase inverter can be attributed to a s...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to View More 
Login to View More