Optimal DC Voltage and Current Control of an LCC HVDC System to Improve Real-Time Frequency Regulation in Rectifier- and Inverter-Side Grids

This paper presents an improved droop-based control strategy for the active and reactive power-sharing on the large-scale Multi-Terminal High Voltage Direct Current (MT-HVDC) systems. As droop parameters enforce the stability of the DC grid, and allow the MT-HVDC systems to participate in the AC voltage and frequency regulation of the different AC systems interconnected by the DC grids, a communication-free control method to optimally select the droop parameters, consisting of AC voltage-droop, DC voltage-droop, and frequency-droop parameters, is investigated to balance the power in MT-HVDC systems and minimize AC voltage, DC voltage, and frequency deviations. A five-terminal Voltage-Sourced Converter (VSC)-HVDC system is modeled and analyzed in EMTDC/PSCAD and MATLAB software. Different scenarios are investigated to check the performance of the proposed droop-based control strategy. The simulation results show that the proposed droop-based control strategy is capable of sharing the active and reactive power, as well as regulating the AC voltage, DC voltage, and frequency of AC/DC grids in case of sudden changes, without the need for communication infrastructure. The simulation results confirm the robustness and effectiveness of the proposed droop-based control strategy.

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Current Control and FPGA–Based Real–Time Simulation of Grid–Tied Inverters

2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe) ◽

10.23919/epe20ecceeurope43536.2020.9215961 ◽

2020 ◽

Author(s):

Sabin Carpiuc ◽

Matthias Schiesser ◽

Carlos Villegas

Keyword(s):

Real Time ◽

Current Control ◽

Real Time Simulation ◽

Time Simulation

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Vector Measurement based Virtual Inertia Emulation Technique for Real-Time Transient Frequency Regulation in Microgrids

IEEE Transactions on Power Electronics ◽

10.1109/tpel.2020.3034699 ◽

2020 ◽

pp. 1-1

Author(s):

Pritam Bhowmik ◽

Pravat Rout ◽

Josep GE M Guerrero ◽

Abdullah M Abusorrah

Keyword(s):

Real Time ◽

Frequency Regulation ◽

Vector Measurement ◽

Virtual Inertia

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Emulation of grid-forming inverters using real-time PC and 4-quadrant voltage amplifier

Forschung im Ingenieurwesen ◽

10.1007/s10010-021-00484-9 ◽

2021 ◽

Author(s):

Wolf Schulze ◽

Maurizio Zajadatz ◽

Michael Suriyah ◽

Thomas Leibfried

Keyword(s):

Real Time ◽

Control Method ◽

Current Control ◽

Control Methods ◽

Test Bed ◽

Test Scenario ◽

Power Semiconductors ◽

Voltage Amplifier ◽

Grid Side ◽

Virtual Synchronous Machine

AbstractA test bed for the evaluation of novel control methods of inverters for renewable power generation is presented. The behavior of grid-following and grid-forming control in a test scenario is studied and compared.Using a real-time capable control platform with a cycle time of 50 µs, control methods developed with Matlab/Simulink can be implemented. For simplicity, a three-phase 4‑quadrant voltage amplifier is used instead of an inverter. Thus, the use of modulation and switched power semiconductors can be avoided. In order to show a realistic behavior of a grid-side filter, passive components can be automatically connected as L‑, LC- or LCL-filter. The test bed has a nominal active power of 43.6 kW and a nominal voltage of 400 V.As state-of-the-art grid-following control method, a current control in the d/q-system is implemented in the test bed. A virtual synchronous machine, the Synchronverter, is used as grid-forming control method. In combination with a frequency-variable grid emulation, the behavior of both control methods is studied in the event of a load connection in an island grid environment.

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A New Method for Phase Difference Estimation Based on Time-Varying Signal Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.333-335.650 ◽

2013 ◽

Vol 333-335 ◽

pp. 650-655

Author(s):

Peng Hui Niu ◽

Yin Lei Qin ◽

Shun Ping Qu ◽

Yang Lou

Keyword(s):

Signal Processing ◽

Real Time ◽

Phase Difference ◽

Time Signal ◽

Time Interval ◽

Time Varying ◽

Signal Model ◽

Time Frequency ◽

Mass Flowmeter ◽

Coriolis Mass Flowmeter

A new signal processing method for phase difference estimation was proposed based on time-varying signal model, whose frequency, amplitude and phase are time-varying. And then be applied Coriolis mass flowmeter signal. First, a bandpass filtering FIR filter was applied to filter the sensor output signal in order to improve SNR. Then, the signal frequency could be calculated based on short-time frequency estimation. Finally, by short window intercepting, the DTFT algorithm with negative frequency contribution was introduced to calculate the real-time phase difference between two enhanced signals. With the frequency and the phase difference obtained, the time interval of two signals was calculated. Simulation results show that the algorithms studied are efficient. Furthermore, the computation of algorithms studied is simple so that it can be applied to real-time signal processing for Coriolis mass flowmeter.

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