An Improved Continuous Commutation Failure Mitigation Method in High Voltage Direct Current Transmission System

Based on the case study of listed enterprises in China’s coal industry, this paper constructs the environmental performance evaluation and implementation process by the data envelopment analysis. Analyze the scale efficiency, efficiency and projection value of 17 coal enterprises, meanwhile, make a horizontal comparison of the environmental performance level among coal enterprises. This paper makes scale improvement and relaxation improvement for invalid cells, finds out the environmental risk spots and makes recommendations for improvement, consequently can guide the coal enterprises to carry out environmental performance management actively and accept public supervision