34 results about "Nonlinear observer" patented technology

The invention discloses a power battery SOC estimation method based on a nonlinear observer. The method comprises the steps of: performing an intermittent discharging-standing experiment on a power battery, and obtaining a SOC and OCV expression; establishing a battery equivalent circuit model; determining each parameter value of the model; establishing a discrete state space model of the battery; designing a self-adaptive nonlinear observer; determining an optimizing target function; solving an optimal parameter value; an calculating an estimated value of the battery SOC. A power battery SOC estimation system based on the optimal self-adaptive nonlinear observer comprises a power battery SOC-OCV expression determining module, an equivalent circuit model establishing module, a parameter determining module, a power battery SOC estimation discrete state space model determining module, a self-adaptive nonlinear observer designing module, a parameter optimizing target function determining module, an optimal parameter solving module and a power battery SOC estimation module. According to the invention, the SOC estimation precision is improved, the algorithm calculated quantity is reduced, hardware realization is facilitated, and the power battery SOC estimation method and system based on the nonlinearity observer are applied to the field of electric vehicle power battery managing systems.

The invention provides an accurate on-line compensation method for the nonlinear effect of an inverter, which belongs to the technical field of motor drive control. The present invention first needs to identify the parameters for designing the nonlinear observer of the inverter, that is, the dq-axis inductance. The used dq-axis inductance identification method fully considers the defects of the classical seven-segment SVPWM modulation method, and rearranges the position of the zero vector , at the same time, without considering the influence of inverter nonlinearity, a flux linkage sliding mode observer based on super-helix algorithm can be designed using the identified dq-axis inductance, and the observed inverter nonlinear voltage can be compensated to the αβ axis voltage reference command . Aiming at the situation that the nonlinear model of the inverter is not clear and the compensation is not accurate enough when the phase current is small, the invention proposes a method for accurately compensating the nonlinearity of the inverter online, which can avoid the dead zone error caused by switching the switch tube. ; Realize precise compensation of inverter nonlinearity.