Abstract-This paper presents a novel modulation strategy for a Modular Multiphase Multilevel Converter especially for the usage in Power Hardware-in-the-Loop Emulation Systems. The proposed modulation scheme generates the required voltage time area by means of an integrator in a quasi continuous operation mode. Therefore, the fixed modulation period is disestablished to achieve a minimum response time of the emulation converter. The switching states of the parallel half-bridges are selected by a sorting algorithm, dependent on the instantaneous branch currents, to avoid saturation in the flux compensated chokes of the converter. The performance of the modulation scheme is verified at a three phase, seven level multilevel converter, with a PWM-frequency up to 120 kHz and an output power of more than 100 kW.
This paper presents an extended dq0-model for small delta-connected Permanent Magnet Synchronous Machines (PMSM), the design of a prototype and the parameterization of the model parameters by testbench measurement. The familiar dq-fundamental equations are thereby extended to consider harmonic effects. This allows the inclusion of the zero-sequence flux-linkage. The model, based on the dq0-flux-linkages and the stator resistance, enables the calculation of the zero-sequence current and a more precise inner torque estimation compared to state of the art fundamental models. The rotor position dependent dq-flux-linkage estimation is based on the measured dq-voltages and the solution of the simplified differential system equation. Detection of the zerosequence current yields to the zero-sequence flux-linkage. In this paper, we also present a prototype design of a PMSM machine with additional zero-sequence current sensing. Testbench measurement at constant controlled currents enables the parameter identification. For validation, the identified parameters are compared with existing Finite Element Analysis.
The demand for high voltage, high power, high precision and high dynamic 3AC-voltage sources is increasing constantly. One application that gets more and more important in recent years and demands such voltage sources is e.g. Power-Hardware-in-the-Loop (PHIL) Emulation. In this paper a new power converter topology called "Parallel Hybrid Converter" or PHC is presented and a corresponding control scheme is derived. This new converter has a terminal behavior similar to a MMC or MMPMC but compared to them the PHC features significantly reduced costs and a significantly improved power density.
Low-and medium voltage power converters for grid applications require bulky and expensive LCL-filters in order to meet the harmonic limits defined by the grid code. This paper presents a novel hybrid converter topology with smaller passive components, composed of a high power main converter with an integrated low power active filter. The presented coupled control strategies for a current-source and a voltage-source topology enable the immediate mitigation of the switching frequency current ripple, significantly decreasing the total harmonic distortion (THD) of the output current to below 0.5 % and thereby eliminating the need for a passive LCL-filter. Compared to LCL-filter based converter systems, a reduction of the inductive component expenditure of up to 50 % is achievable even for a very low active filter to main converter power rating ratio of 10 %. The outstanding harmonic performance and reduced passive component demand of the hybrid converter allow increased power density and efficiency as well as lower costs of low-and medium voltage power converters.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.