A controllable load method of frequency converter power electronics based on grid-connected inverter
A technology for power electronics and inverters, which is applied to instruments, measuring electricity, and measuring electrical variables. It can solve problems such as energy waste, limited power consumption, and waste of electrical energy in the test process, so as to achieve a simple test system and reliable load characteristics. Control, good practical effect
Active Publication Date: 2018-06-12
STATE GRID CORP OF CHINA +1
View PDF8 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Hysteresis dynamometers, excitation motors and other simulated loads can be used for inverter testing, but energy-consuming loads not only completely waste the electrical energy in the test process, but also are affected by the control response speed and quality, making it difficult to accurately simulate the auxiliary loads of the inverter. machine load characteristics
On the other hand, energy-consuming loads are limited by heat dissipation and other factors, and the power consumption level is limited, which is limited to the simple test application of low-power inverters, and cannot be applied to the test of high-power inverters, and the remaining electric energy cannot be fed back to the inverter during the test. power grid, resulting in a waste of energy
At the same time, this test method is difficult to simulate the exact characteristics of the auxiliary load of the frequency converter
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 moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0021] see figure 1 , the present invention provides a frequency converter power electronic controllable load method based on grid-connected inverter, the main circuit structure is divided into pre-transformer, uncontrolled rectifier, intermediate DC capacitor, inverter, filter And post transformer six parts. Two of the transformers have an isolation function, and the frequency converter, inverter, and power grid are all isolated, which improves the safety of the system and simplifies the design.
[0022] General inverter output line voltage effective value U sm =380V, when no pre-transformer is connected or when the transformation ratio of the pre-transformer is 1, after uncontrolled rectification, the DC capacitance C 2 The rated voltage is U dm ≈513V, which is obviously less than the input threshold voltage U that makes the inverter output 380V line voltage dT . There are two solutions for this: one is to step up the front transformer to increase the output voltage of ...
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 frequency converter power electronics controllable loading method based on a grid connected inverter. In a present frequency converter test, a dissipating energy type load completely wastes the electricity energy in a test process, and is difficult to accurately simulate load characteristics of the subsidiary engine of the frequency converter. In the method, the output terminal of a frequency converter is directly in connection with a three-phase grid connected inverter to be used as the artificial load of the frequency converter; the main circuit structure successively comprises a front transformer, an uncontrolled rectifier, an intermediate DC capacitor, an inverter, a filter and a rear transformer from front to back; different current given signals are given to the three-phase grid connected inverter to stimulate different load current characteristics; and the three-phase grid connected inverter is controlled by employing the current inner loop strategy based on a PI regulator in a two-phase rotating coordinate system. The method can be used in a high power frequency converter test, and realize reactive power balance control; in a whole process, almost all energy can be fed back to a power grid.
Description
technical field [0001] The invention relates to the technical field of power electronics, in particular to a controllable load method of frequency converter power electronics based on a grid-connected inverter. Background technique [0002] Regardless of the need for technology or energy saving, frequency converters have been widely used in auxiliary machines of steam turbine generator sets in thermal power plants. The fluctuation of the input power supply voltage of the inverter will affect the stable operation of the inverter. In order to improve the high and low voltage ride-through capability of the low-voltage inverter, an additional voltage support device is often used to solve the impact of swaying electricity on the stable operation of the inverter. [0003] In order to check whether the anti-voltage fluctuation level of a type of auxiliary low-voltage inverter itself and the high-voltage and low-voltage ride-through capabilities after the configuration of additional...
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
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01R31/00
Inventor 吴跨宇蔡慧宣晓华黄晓明楼伯良卢岑岑卢嘉华熊鸿韬沈轶君陆海清马智泉
Owner STATE GRID CORP OF CHINA