Non‐linear behavioural modelling of device‐level transients for complex power electronic converter circuit hardware realisation on FPGA

Abstract

Detailed device-level models of the insulated-gate-bipolar-transistor (IGBT) and diode are essential for power converter design evaluation for providing insight into circuit and device behaviours, as well as to shorten the design cycle and reduce costs. In this study, the non-linear behavioural models of IGBT and power diode are utilised for emulating the modular multilevel converter (MMC) on the field programmable gate array. For digital hardware-in-the-loop (HIL) emulation, these timedomain continuous models are discretised and linearised prior to being designed into the corresponding hardware modules using the hardware description language VHDL that features a fully paralleled and pipelined implementation. A circuit partitioning approach is adopted according to the MMC structure to enhance computation efficiency and then, detailed information from the system-level performance to the specific features of individual switches is available. HIL emulation and the subsequent comparison with results from the commercial off-line simulation tools prove that the complex IGBT and diode models can be involved in the efficient simulation of large-scale power converters. 2 Non-linear behavioural device model 2.1 Power diode non-linear behavioural model The power diode is simplified with only static features and the reverse recovery dynamics preserved while other negligible components in the original full behavioural model [24] are omitted, as shown in Fig. 1a. 2.1.1 Model description: The diode static characteristics represented by the symbol NLD reflects an exponential relationship IET Power Electron.

Device‐level modelling and FPGA‐based real‐time simulation of the power electronic system in fuel cell electric vehicle

“…In the PMSM solver, the three-phase voltages are transformed from abc frame to dq frame. The dq currents and the rotor speed can be computed based on (8). Afterward, the currents in the abc frame can be obtained by the reverse transformation.…”

“…The P L is the IGBT power loss (W), T j is the junction temperature (°C), T c is the case temperature (°C) and T a is the ambient temperature (°C). The equivalent time-derivate model can be solved by using the forward-Euler method to discretise the state-space equations, as shown in (8). The power losses lead to a temperature variation of the junction which in turn affects the characteristics of IGBT.…”

“…The electrical stress, as well as the thermal stress, can be thus evaluated in real time. However, the device‐level simulation involves the complex switch model, which is usually non‐linear and requires iterative solvers [7, 8]. It introduces additional computation amounts in each time‐step and a large computational latency is inevitable.…”

Real-Time Simulation of Hybrid Modular Multilevel Converters Using Shifted Phasor Models

“…MMC offers a better prospect for cost-effective power transmissions [1], [2]. In practical MMC projects, the real-time simulation on FPGA plays an essential role in the implementation of the control and protection systems [3], [4]. Since the voltage and current stresses in the circuits and components of MMC are critical for the design of its control and protection strategies, the real-time simulations need to provide the very details of dynamic responses of the system, including dynamics not only at the system level but also at the sub-module level.…”

“…For the real-time simulation based on field programmable gate arrays (FPGAs), both sub-module level and system level dynamics are required for detailed studies of a MMC-based system. However, the sub-module level modeling of MMC has always been a challenging task due to the large number of sub-modules in a single arm [3], [4]. On the one hand, the massive switching components greatly increase the number of nodes and the size of the admittance matrix of the system.…”