PATENT CLAIM ANALYSIS

Application Number: 16216448
Application Type: Utility
Filing Date: 2018-12
Publication Date: 2019-09
Patent Classification: ["363", "098000"]

Abstract:
Nonlinear control method for the micro-grid inverter with anti-disturbance. By generating reference currents that satisfy specific active and reactive power command under various working conditions, and introducing a nonlinear control method based on Lyapunov function to control the inverter, fast and accurate tracking of the generated reference signals is realized. The method realizes effective decoupling control of active power and reactive power. The system has high dynamic response and good robustness. Besides, the control structure of the method is simple and easy to implement, and the synchronous control link and the additional voltage and current regulator are omitted. The method realizes fast and accurate power exchange and stable power transmission between the inverter and the grid in the micro-grid under various working conditions, and provides a guarantee for improving the energy management efficiency within the micro-grid.

Claim (Index 1):
A nonlinear control method for a micro-grid inverter with anti-disturbance, comprising:\n (1) collecting a filter capacitor voltage v c  of an LCL type grid-connected inverter and a grid-side inductance current i o , and building a mathematical model of the grid-connected inverter in a two-phase stationary coordinate system through coordinate transformation as follows: di o \ue89e \ue89e \u03b1\u03b2 dt = x \u03b1\u03b2 - d ; dx \u03b1\u03b2 dt = u \u03b1\u03b2 ( 17 ) wherein i o\u03b1\u03b2  represents a grid-side inductance current in the two-phase stationary coordinate system; u \u03b1\u03b2  represents a nonlinear control law in the two-phase stationary coordinate system; x \u03b1\u03b2  is a state variable as follows:\n x \u03b1\u03b2 =v c\u03b1\u03b2 / L o \u2003\u2003(18) \n d is a disturbance including error caused by system disturbance and model uncertainty as follows: d = 1 L o \ue89e ( v g \ue89e \ue89e \u03b1\u03b2 + \u0394 \ue89e \ue89e v g \ue89e \ue89e \u03b1\u03b2 ) + i o \ue89e \ue89e \u03b1\u03b2 L o \ue89e ( R o + \u0394 \ue89e \ue89e R o ) + 1 L o \ue89e ( \u0394 \ue89e \ue89e L o \ue89e i . o \ue89e \ue89e \u03b1\u03b2 - \u0394 \ue89e \ue89e v c \ue89e \ue89e \u03b1\u03b2 ) ( 19 ) wherein  L o  is an estimate of a sum L o  of a grid-side filter inductance and a line inductance; \u0394v g\u03b1\u03b2  is a disturbance caused by a grid voltage; R o  is a value of a line resistance; \u0394R o  and \u0394L o  are deviations between an actual applied value and a theoretical value due to uncertainty of line parameters; \u0394v c\u03b1\u03b2  is an effect of a grid voltage disturbance on a capacitor voltage; i load\u03b1\u03b2  represents the load current in the two-phase stationary coordinate system; v g\u03b1\u03b2  represents a grid voltage in the two-phase stationary coordinate system; (2) collecting an AC bus voltage v g  and a local load current i load  and generating a grid-side inductance current reference signal i o\u03b1\u03b2_ref  in the two-phase stationary coordinate system according to an instantaneous reactive power theory after coordinate transformation as follows: i o \ue89e \ue89e \u03b1\u03b2_ \ue89e ref = [ i o \ue89e \ue89e \u03b1_ \ue89e ref i o \ue89e \ue89e \u03b2_ \ue89e ref ] = [ i load \ue89e \ue89e \u03b1 i load \ue89e \ue89e \u03b2 ] - [ i g \ue89e \ue89e \u03b1 i g \ue89e \ue89e \u03b2 ] , ( 20 ) calculating a grid-connected current i g\u03b1\u03b2  by equation (5): i g \ue89e \ue89e \u03b1\u03b2 = [ i g \ue89e \ue89e \u03b1 i g \ue89e \ue89e \u03b2 ] = 2 3 \u00b7 1 v g \ue89e \ue89e \u03b1 2 + v g \ue89e \ue89e \u03b2 2 \ue8a0 [ v g \ue89e \ue89e \u03b1 v g \ue89e \ue89e \u03b2 v g \ue89e \ue89e \u03b2 - v g \ue89e \ue89e \u03b1 ] \ue8a0 [ P set Q set ] ( 21 ) wherein P set  and Q set  are given active power and reactive power commands, respectively; (3) setting an original tracking error e \u03b1\u03b2  and a filter tracking error E \u03b1\u03b2  of a control variable i o  as follows:\n e \u03b1\u03b2 =i o\u03b1\u03b2 \u2212i o\u03b1\u03b2_ref ;E=E \u03b1\u03b2 =ke \u03b1\u03b2 +\u0117 \u03b1\u03b2 \u2003\u2003(22) \n wherein i o\u03b1\u03b2_ref  is the reference current signal; k is a custom constant greater than zero; \u0117 \u03b1\u03b2  is a first derivative of the original tracking error e \u03b1\u03b2 ; defining a tracking error as follows:\n r=r \u03b1\u03b2 =\u03b1E \u03b1\u03b2 +\u0116 \u03b1\u03b2 \u2003\u2003(23) \n wherein a derivative of the reference current signal i o\u03b1\u03b2_ref (t) is taken by an observer to obtain a first derivative {dot over (i)} o\u03b1\u03b2_ref (t) and a second derivative \u00ef o\u03b1\u03b2_ref (t) of the reference signal as input signal values of the nonlinear controller and build a grid-connected inverter nonlinear control model as follows: u \u03b1\u03b2 \ue8a0 ( t ) = - kx \u03b1\u03b2 \ue8a0 ( t ) - ( \u03bb + k s ) \ue89e E \u03b1\u03b2 \ue8a0 ( t ) + k \ue89e i . o \ue89e \ue89e \u03b1\u03b2_ \ue89e ref \ue8a0 ( t ) + i \u00a8 o \ue89e \ue89e \u03b1\u03b2_ \ue89e ref \ue8a0 ( t ) - \u222b 0 t \ue89e ( \u03bb \ue89e \ue89e k s + 1 \u03c1 ) \ue89e E \u03b1\u03b2 \ue8a0 ( \u03c4 ) \ue89e d \ue89e \ue89e \u03c4 ( 24 ) wherein i load\u03b1\u03b2  represents the load current in the two-phase stationary coordinate system; k, \u03bb, k s , p are custom constants greater than zero, respectively; (4) obtaining a modulated wave signal according to the LCL type grid-connected inverter mathematical model and the grid-connected inverter nonlinear control model in a three-phase stationary coordinate system after coordinate transformation as follows: v s \ue89e \ue89e \u03b1\u03b2 = 1 K d \u00b7 v i \ue89e \ue89e \u03b1\u03b2 = 1 K d \u00b7 { d dt \ue89e ( L _ o \ue89e C _ \u00b7 u \u03b1\u03b2 + i o \ue89e \ue89e \u03b1\u03b2 ) \ue89e L _ i + v c \ue89e \ue89e \u03b1\u03b2 } ( 25 ) wherein v i\u03b1\u03b2  represents an inverter input voltage signal in the two-phase stationary coordinate system; K d  is a scaling factor that is greater than zero and a DC voltage value of an inverter side;  L i ,  C ,  L o  are estimates of the inverter-side filter inductance L i , the filter capacitor C, and the sum L i  of grid-side filter inductance and the line parameter; v c\u03b1\u03b2  represents the capacitor voltage component in the two-phase stationary coordinate system; and (5) controlling the grid-connected inverter by introducing a nonlinear control method based on Lyapunov function and using the modulation wave signal in the three-phase stationary coordinate system.

Metadata:
- Claim Count in Document: 1.0
- Percentile: 98.0
- Lexical Diversity: 1.8375
- Patent Class: 363.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: True
- Related Applications: ['15307809', '13030501', '10467007', '15031479', '14841195']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.789448725453051
- 35 USC 102 Novelty (BERT): 0.522632101381459
- Combined Prediction Score: 0.7627670630458918
- Mean Citation Score: 260.269062
- Max Citation Score: 323.55344
- Similarity Product: 235.02029546702383

Labels:
- Claim Label 101: 0
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 1
- Combined Label: 0
- Label 101 Adjusted: 0

Dataset: test