Research On The Technology Of Contactless On-load Automatic Regulating Voltage Based On Taking Voltage From High Side

Diversified load causes the voltage fluctuation problem is getting worse. In the case of sufficient reactive power, distribution transformers OLTC technology is the most effective way to stabilize the voltage. Non-contact on-load automatic regulating voltage distribution transformers play a vital role in the future power grid, its development and promotion is of great significance. In recent years, domestic and foreign experts and scholars for the non-contact on-load automatic voltage regulation technology did a lot of research, in this laboratory early study also done a lot of research for the project and achieved outstanding results, successfully developed a non-contact automatic voltage regulator load distribution transformer prototype. However, there are still some problems during operation, seriously affect the reliability of its operation, in particular the insulation problem between high and low of distribution transformer.Silicon Controlled Rectifier as tap located distribution transformer high side, but the trigger circuit triggered tap turned on and off is positioned low pressure side, and the control system to issue commands is also located in the low pressure side, in this way, when a single-phase ground fault appeared in distribution transformer high side, the control system located on the low pressure side and tap-located high-pressure side will bear a larger high voltage. Using power transformers and optical coupler to achieve the purpose of high and low voltage insulation can not be achieved,so resulting in the entire device damaged. In order to avoid such phenomenon, during the laboratory study, found that optical fiber communication technology has good electrical isolation,so chose the optical fiber communication technology and non-contact on-load tap technology,using the advantage of optical fiber communication technology high pressure electrical isolation,designed Silicon Controlled Rectifier trigger circuit and starting circuit based on optical fiber.Although the use of fiber optic technology successfully solved non-contact on-load tap high and low voltage distribution transformer insulation problems, but due to the high cost of fiber-optic communication, the technical solution is not conducive to the promotion and application of large area in the future.To solve this problem, in order to promote application engineering of non-contact on-load tap distribution transformers. In this paper, we design a new non-contact on-load automatic voltage regulator technology program, which is based on taking voltage from the high pressure side ofnon-contact on-load automatic regulating voltage distribution transformer. From the distribution transformer high voltage side A-phase winding between two points take voltage. The voltage on the one hand to provide power to the entire control system, on the one hand for detecting the voltage, so that the control system and the tap are located on the same side of the distribution transformer, from the fundamental solution to the problem of the insulation between high and low pressure.This research program designed a new way to start, no special start branch. By conducting rated stall tap connected high voltage winding and neutral point start the distribution transformer.Specific process: on the moment of power distribution transformer, there is a delay in MCU monitoring system. By designing trigger circuit tap-rated use voltage applied across it is turned on.In order to prevent non-rated file tap also in the conduction state, resulting in circulation, between the switch located non-rated file and fuse installed AC contactor normally open contact, so at the power distribution transformer instance only the branch through rated file tap connect the neutral point in the conduction state, non-contact on-load distribution transformer is normal startup. After the delay of SCM control system, the regulator into the normal procedures to achieve load automatic voltage regulator.The research program simulation experiment was conducted in laboratory. Using existing laboratory equipment: a three-phase voltage regulator with over current protection cabinets and a0.4 / 10 kV step-up transformer constitutes high voltage regulator, simulation grid voltage changes,supply power to 30kVA-10/0.4kV experiment prototype, respectively, in the no-load, resistive load inductive and resistive load experiment. The results showed that the non-contact load tap distribution transformers can be started normally and can be smooth surge.After laboratory simulation experiments feasible, brought the experimental device to the production workshop of Harbin Greider Power Equipment Co. Ltd on-site load test.The results showed the distribution transformer start reliable, smooth running, and then apply the experimental program to produce experimental prototype, within the workshop as a hanging plant transformer, run almost a year has not any problems.