TY - JOUR

T1 - An Improved Submodule Capacitor Voltage Measuring Algorithm for MMC with Reduced Sensors

AU - He, Ruizhi

AU - Liu, Dong

AU - Zhang, Qi

AU - Teodorescu, Remus

AU - Hou, Weiyang

AU - Chen, Zhe

PY - 2021/7/10

Y1 - 2021/7/10

N2 - The nearest level modulation (NLM) based submodule capacitor voltage measuring technology for a modular multilevel converter (MMC) with reduced sensors can effectively reduce the costs of the data acquisition system of MMC and simplify the operation system. One of the technical challenges of this submodule capacitor voltage measuring technology is to reduce the measurement errors of submodule capacitor voltage. This paper proposes an improved submodule capacitor voltage measuring algorithm to overcome this challenge. In the proposed algorithm, by keeping the operation states of submodules unchanged during the continuous control period, the probability of obtaining the actual capacitor voltage is increased, and then the number of corrections of observed capacitor voltage is significantly increased. Thus, the proposed algorithm can effectively reduce the measuring errors. More significantly, the proposed algorithm can also improve the measurement accuracy even in the capacitance deviation situation. Finally, both simulation and experimental results are provided to verify the feasibility and effectiveness of the proposed voltage measuring algorithm.

AB - The nearest level modulation (NLM) based submodule capacitor voltage measuring technology for a modular multilevel converter (MMC) with reduced sensors can effectively reduce the costs of the data acquisition system of MMC and simplify the operation system. One of the technical challenges of this submodule capacitor voltage measuring technology is to reduce the measurement errors of submodule capacitor voltage. This paper proposes an improved submodule capacitor voltage measuring algorithm to overcome this challenge. In the proposed algorithm, by keeping the operation states of submodules unchanged during the continuous control period, the probability of obtaining the actual capacitor voltage is increased, and then the number of corrections of observed capacitor voltage is significantly increased. Thus, the proposed algorithm can effectively reduce the measuring errors. More significantly, the proposed algorithm can also improve the measurement accuracy even in the capacitance deviation situation. Finally, both simulation and experimental results are provided to verify the feasibility and effectiveness of the proposed voltage measuring algorithm.

KW - MMC

KW - submodule capacitor voltage measurement

KW - reduced sensors

KW - measurement errors reduction

UR - https://ieeexplore-ieee-org.zorac.aub.aau.dk/document/9477618

M3 - Journal article

SP - 1

EP - 17

JO - I E E E Sensors Journal

JF - I E E E Sensors Journal

SN - 1530-437X

ER -