Quality service is one key work of power supply companies. Customer complaints contain a lot of intrinsic feature information, such as customer demand and service defects. Analysis of customer complaint data can effectively identify service shortcomings and provide guidance for improving quality service. In this paper, complaint behavior of electric power customers are analyzed from three aspects, including complaint contents, complaint time and complaint areas. The related factors and risk index of customer complaints are studied. The suggestions to reduce complaints are proposed. The conclusions can provide a reference for quality service of power supply company.
A.Power Supply Quality Complaints The main reasons for 241 cases of power supply quality complaints include frequent blackouts and abnormal voltage quality. There were 215 complaints caused by frequent blackouts, accounting for 89.2%. And the rest was caused by low voltage, a total of 26 cases, which occurred from 2015 to 2017. Frequent blackouts complaints refer to the complaints caused by three times power outages occurred within two months. 215 frequent blackouts complaints involved 715 power outages, including fault blackouts and planned blackouts. The number of fault blackouts is 446, accounting for 62.4%. Fault blackouts are mainly caused by equipment faults due to equipment problems, tree barricades, external breakdown, weather and other factors. Equipment faults are mainly concentrated in low-voltage lines, distribution cabinets and low-voltage branch boxes. Fig. 2 shows the trends of fault blackouts and planned blackouts involved in frequent blackouts complaints. In this figure, 96 means planned blackouts number in 2015, and 67.61% means the proportion of planned blackouts and fault blackouts in 2015. Other number has similar meanings. The proportion of planned blackouts decreased sharply at first and then increased slightly. 36 frequent blackouts complaints were caused by unreasonable planned blackouts arrangement, which meant the number of planned blackouts in the same area reached three or more times within 2 months. The number of occurrences of this problem is decreasing year by year, eighteen in 2015, sixteen in 2016, two in 2017 and zero in 2018, which shows that planned blackouts arrangement of EZ power supply company become more and more reasonable. The fault blackouts gradually become the main reason for frequent blackouts complaints.
According to the 10kV lines involved in frequent blackouts complaints, 39 lines had two or more frequent blackouts complaints, a total of 166 cases. Seven lines had eight or more frequent blackouts complaints, which should be listed as the focus of distribution network transformation projects. B.Business Complaints The reasons of 151 business complaints involve meter-reading and payment-collection, business expansion, energy metering, electricity prices and fee, change of electricity use category and so on. Fig. 3 shows the classification and proportion of business complaints. Among them, the number of complaints caused by meter-reading and payment-collection is the maximum, followed by business expansion. The 54 complaints caused by meter-reading and payment-collection mainly include 20 cases about meter-reading, 19 cases about reminding electric charge and 15 cases about restoration of power delivery in arrears of power outage. The 44 complaints caused by business expansion mainly include 31 cases about overtime complaints and 13 cases about improper handling.
C.Service Complaints 94 service complaints involve service behavior and service channels, including 90 cases about service behavior complaints, accounting for 95.7%. The service behavior complaints mainly include 49 cases about personnel violations and 41 cases about personnel service attitude. D.Power Grid Construction Complaints 72 power grid construction complaints consist of power construction and power supply facilities, of which 68 cases are complaints about power gird construction, accounting for 94.44%. The power grid construction complaints mainly include 37 cases about irregular construction services, 27 cases about improper restoration at the construction site and 4 cases about poor service attitude of construction workers. E.Power Outage and Supply Complaints 64 power outages and supply complaints involve emergency repair services, power outage and information announcements of power outage and supply, including 36 cases about emergency repair services and 25 cases about power outage. Code Shoppy Emergency repair service complaints include 28 cases related to poor service attitude and irregular service, and 8 cases related to emergency repair overtime. Power outage complaints include 13 cases related to delayed transmission and 12 cases related to unprovoked blackouts.
In order to analyze the impact of different factors on complaints, the Pearson correlation coefficient can be used to analyze the correlation between each factor and complaints. The Pearson correlation coefficient is a measure of the linear correlation between two variables X and Y. It has a value between +1 and −1, where 1 is total positive linear correlation, 0 is no linear correlation, and −1 is total negative linear correlation. The Pearson correlation coefficients of complaints and repair number of power failure, the maximum load of the main network, and the maximum temperature are 0.47, 0.32, and 0.19, respectively. It can be seen that the number of complaints is positively correlated with repair number of power failure, the maximum load of the main network and the maximum temperature. Particularly, the number of complaints is moderately correlated with repair number of power failure and is weakly correlated with the maximum load of the main network; however, it is not significantly correlated with the maximum temperature. Fig. 15 shows the change of complaints, repair number of power failure, the maximum load of the main network, and the maximum temperature.
There are 199 complaints about frequent blackouts, poor service attitude and irregular service during emergency repair. There are 26116 repair orders for power failure. An average of about 130 repair orders for power failure would generate one complaint. There are 231 complaints due to power outages, including frequent blackouts, power outage and unplanned blackout. A total of 3,565 power outages information were issued. An average of about 15 power outages would result in one complaint