| As one of large industry dust arresters, electrostatic precipitator (ESP) can collect dust efficiently, and can run under high temperature, and deal with large scale smoke, etc. So ESP has been applied to power plants, cements plants and steel plants widely, which has become the main arrester equipment. However, ESP is facing the new challenge now:1. Traditional ESP maintains and control are still done artificially or half-art ificially, which can' t meet the real demands of field; the automation and intelligentizing become the most urgent tasks of ESP.2. Because of China strict control of sulfur dioxide emission, the low-sulfur high resistance dust becomes the main disposal object of ESP. When ESP deals with the high resistance dust, back corona failure happens easily, which can reduce the efficiency of ESP, and make ESP run unstably. How to detect back corona fai lure, especially early back corona, is one of urgent problems which ESP should be solved.3. Because ESP system runs under the surrounding of high temperature, high voltage and strong machine vibration, many kinds of failure easily happens, such as machine failures, electric failures and so on. How to detect these failures in time and efficiently to ensure ESP system run stably and efficiently is an important problem of ESP.This paper sets up one laboratory ESP system, and researches back corona failure and plate-line distance shorten failure. And the transient signals of two kinds of ESP failures are analyzed by this paper, which aims to find new method to detect these failures and modify the old methods. And this paper researches the fieldbus application in ESP, and designs one set of ESP real-time monitor and control system.The detailed jobs are as follows.1. This paper analyzes secondary voltage and secondary current transient signals of back corona failure and plate-line distance shorten failure on both time domain and frequent domain; and contrasts the results with ESP volt-ampere curves to prove the feasibility of transient signals application in ESP failures detection.2. The ESP secondary voltage and secondary current transient signals of back corona failure and plate-line distance shorten failure are analyzed by PRONY method, and the results of PRONY method are used to detect these two ESP failures.3. This paper sets up one ESP real-time monitor and control system based on CANBUS, and designs CANBUS intelligent node, CANBUS adapter, supervisory computer and so on.4. And real-time task dispatch theory is researched by this paper, and one smallest CANBUS laboratory system is set up to research the delay of CANBUS to find the new method to solve the CANBUS clock synchronization.5. The interference sources of ESP field are analyzed, and the method to improve the anti-interference ability and EMC ability of ESP real-time monitor and control system are designed.The conclusions of this paper are as follows.1. This paper confirms that vibration damping character of secondary voltage . transient signals and secondary current transient signals of ESP spark dischargecan predict and detect the ESP back corona failure efficiently.2. And this paper also confirms that vibration damping character of secondary voltage transient signals and secondary current transient signals of ESP spark discharge can detect and distinguish two easily confused failures-ESP back corona failure and ESP plate-line distance shorten failure.3. PRONY method can get the damping ratio of transient signals which can be used to predict and detect the early back corona failure efficiently, and this method makes up the deficiencies of ESP volt-ampere curve.4. And PRONY method can get the damping ratio of transient signals which can be used to detect and distinguish two easily confused failures-ESP back corona failure and ESP plate-line distance shorten failure, and this method also makes up the deficiencies of old ESP plate-line distance shorten failure detection method. It is the new development of the old method.5. ESP real-time mon... |
