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For lack of the appropriate global distribution of dc currents, the conventional suppression method to suppress dc bias based on capacitive dc blocking device (BD) redirects current to the ground as much as possible, which predisposes to the exceeding neutral current of other transformers in the regional power grid and leads to the contradiction between the power grid corporation and other public enterprises. Therefore, this paper presents a flexible suppression method for dc bias based on a novel dc-bias suppression device. First, a current balancing device (CBD) based on adjustable parallel resistances is designed. The mathematical model for global optimal switching of CBDs is established by a field-circuit coupling method with the equivalent resistance network of an ac system along with the location of substations and ground electrodes. The optimal switching scheme to minimize the global maximum dc current is obtained by gravitational search algorithm. Based on the aforementioned work, we propose a suppression strategy considering electro-corrosion of metal pipelines. The effectiveness and superiority of suppression methods are verified by comparative case studies of the Yichang power grid. [ABSTRACT FROM PUBLISHER]

Background: Tuberculosis (TB) patients in China encounter heavy financial burdens throughout the course of their treatment and it is unclear how China's health insurance systems affect the alleviation of this burden under the integrated approach. This study aimed to measure reimbursement for TB services under the New Cooperative Medical Scheme (NCMS) in rural China and to evaluate changes in catastrophic health expenditure (CHE) caused by the reimbursement policies. Methods: Reimbursement data were obtained from routine data systems for the NCMS in Yichang (YC) and Hanzhong (HZ). 1884 TB inpatients reimbursed by NCMS from 2010 to 2012 were included. Household surveys were conducted. A total of 494 TB patients under the NCMS were selected in this paper. 12 Focus Group Discussions (FGDs) were held. We measured the impact of the NCMS by counterfactual analysis, which analyzed the financial burden alleviation. Equity was assessed by Concentration Index (CI), and disaggregated by project sites. Results: TB inpatients were reimbursed with an effective reimbursement rate of 57.3 %. Average out-of-pocket (OOP) payments for outpatient and inpatient services after diagnosis were 1413 yuan and 430 yuan, and 3572 yuan and 3013 yuan in YC and HZ, respectively. The reimbursement level for TB outpatient care after diagnosis was very low due to a limited outpatient quota. TB patients in HZ incurred higher effective reimbursement rates, but the incidence of CHE remained higher. The reduction of CHE incidence after the NCMS showed no difference statistically (P > 0.05). The severity of CHE was alleviated slightly. CIs after reimbursement were all below zero and their absolute values were higher than those before reimbursement. Conclusions: Low reimbursement for TB patients could lead to heavy financial burden. Poor TB patients incurred high rates of CHE. The NCMS was found to be a protective factor for CHE, but the impact was modest and the equity of CHE did not improve. The NCMS reimbursement policies should be improved in the future to include a more comprehensive coverage of care. Supplemental programs may be necessary to expand coverage for TB care. [ABSTRACT FROM AUTHOR]