A nonlinear model predictive controller design for residual current compensation inverters in rapid earth fault current limiters to mitigate powerline bushfires

Fault compensations in resonant grounded power systems with residual current compensation inverters using an adaptive nonlinear extended state observer‐based model predictive controller

“…The dynamical model of the RCC inverter can be determined from Figure 1 and the neutral current dynamic can be represented as [22]: $$$$\begin{eqnarray} \begin{aligned} \dfrac{di_N}{dt}&=\dfrac{mV_{dc} - v_N}{L_p}, \end{aligned} \end{eqnarray}$$$$where $$i_{N}$$ is the neutral current, $$m={2u}/{V_{dc}}$$ is the modulation index with $$V_{dc}$$ as the RCC inverter's input DC voltage and u as the switching control input, $$v_{N}$$ is the neutral voltage, and $$L_{p}$$ is the inductance of the ASC within the REFCL. Equation (1) can be expressed as: $$$$\begin{eqnarray} \begin{aligned} \dot{x}_1 &=b_{0} u +d_{0} v_N\\ y&= x_1 \end{aligned}, \end{eqnarray}$$$$where $$x_1 = i_N$$ is the state of the system, $$b_{0}=2/L_{p}$$…”

“…The discrete‐time SMC in [21] uses the discrete model of RGPSs with RCC inverters and assists in the practical implementation though it uses a traditional sliding surface which makes it vulnerable to chattering. A nonlinear MPC as presented in [22] offers more flexibility for the practical implementation while performing all optimizations in the off‐line. However, it does not consider any uncertainties in parameters and disturbances within dynamical model of RGPSs with RCC inverters and it is worth further investigating these issues using a similar but advanced approach.…”

“…A nonlinear MPC is designed where the estimated disturbance and adapted parameter are incorporated to compensate the effect of disturbance and parameter variations while ensuring the desired fault compensation. The performance of the proposed ANLESO‐based MPC (or simply ANLESO‐MPC) is evaluated using the software‐based platform (MATLAB/Simulink) and real‐time platform utilizing the OPAL‐RT simulator to demonstrate its parameter adaptation and disturbance estimation capabilities along the fault compensation behaviors in terms of compensating fault current and faulty phase voltage following the guideline in [6]. The fault compensation characteristics of the ANLESO‐MPC is compared with an MPC as presented in [22] for a range of fault impedances.…”

A hybrid sliding mode control scheme for rapid earth fault current limiters in compensated distribution networks in bushfire prone areas

“…Furthermore, switching losses are significant in the existing full-bridge inverter. A nonlinear model predictive scheme is presented in [23] with a T-type RCC inverter which exhibits significant lower switches losses; however, it uses a nominal model to design the controller. The methods in [20,21] consider bounded parametric uncertainty without justifying the role of parametric uncertainty.…”

Control of arc suppression devices for reducing powerline bushfires in resonant grounded power distribution networks using global terminal sliding mode controller

“…An MPC is presented in ref. [20] which is designed using the discrete‐time model of ASDs and makes the implementation easy but it still suffers from the robustness against disturbances and requires precise parametric information. An integral‐SMC (I‐SMC) is presented in ref.…”