A multi-level inverter grid-connected system and method
A multi-level inverter and inverter technology, which is applied in the direction of electrical components, single-network parallel feeding arrangement, AC power input conversion to DC power output, etc., can solve the problem of inability to form a constant switching frequency, inverter and Network filter design difficulties and other issues
Active Publication Date: 2020-01-03
NANJING UNIV OF SCI & TECH
View PDF2 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0003] However, the finite set model predictive control itself is a nonlinear control strategy. When it is applied to the grid-connected control of multi-level inverters, it has the disadvantage of not being able to form a constant switching frequency, which not only makes the grid-connected filter of the later inverter The design becomes very difficult, and it will bring problems such as electromagnetic compatibility
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 1
[0116] The simulation result of embodiment is as shown in the figure: Figure 6 DC side midpoint voltage, Figure 7 Incoming active power, Figure 8 Incoming reactive power, Figure 9 Actual in-grid current and reference in-grid current, Figure 10 The voltage u of the middle point (O) of the AC output side (a) of the inverter relative to the DC side ao The spectrum distribution of the simulation parameters are shown in Table 1.
[0117] From the simulation results of the embodiment, it can be seen that the multi-level inverter grid-connected system and method proposed by the present invention can well suppress the midpoint voltage of the DC side and control the actual grid-connected current under the condition of keeping the switching frequency constant Track the given reference current, so as to realize the control of the active power and reactive power of the network.
[0118] Table 1 Simulation parameters
[0119] Grid voltage e a (=e b = e c ) amplitu...
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 multi-level inverter grid connected system and method. The system comprises a main power circuit, a control circuit and a detection circuit. The main power circuit comprisesan NPC three-phase three-level inverter and an L-type low-pass filter. The detection circuit comprises a grid current detection circuit, a grid voltage detection circuit and a DC side midpoint voltagedetection circuit. The method comprises the steps of first introducing a correction parameter lambda to correct an output voltage vector table of a multilevel inverter according to the fixed frequency principle; and then performing two-step predictive control on a DC side midpoint voltage and an AC side output current of the multilevel inverter according to the corrected output voltage vector table. According to the multi-level inverter grid connected system and method, under the condition of constant switching frequency, finite set model predictive grid connection control is performed on themultilevel inverter, to achieve strong suppression of the DC side midpoint voltage and accurate tracking of the AC side output current.
Description
technical field [0001] The invention relates to the technical field of DC-AC converters of electric energy conversion devices, in particular to a multi-level inverter grid-connected system and method. Background technique [0002] NPC (Neutral Point Clamped) three-phase three-level grid-connected inverter is a multi-level inverter widely used in medium and large-capacity distributed grid-connected power generation systems. Its control strategies mainly include: PI control, PR control, hysteresis control and finite set model predictive control. Among them, the finite set model predictive control has the advantages of strong robustness, rapidity, easy digital realization and consideration of inverter nonlinearity, etc., and is widely used in the grid-connected control of multi-level inverters. [0003] However, the finite set model predictive control itself is a nonlinear control strategy. When it is applied to the grid-connected control of multi-level inverters, it has the d...
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): H02M7/483H02J3/38
Inventor 马丙辉吕建国王纪东阎亦然范林勇
Owner NANJING UNIV OF SCI & TECH