Low pressure on the operation and management of reactive power compensation equipment
Wattless power is an important factor to influence is also pressing quality and economic operation of the power grid, it is necessary to strengthen the comprehensive management of the quality of the voltage and idle work electric power, improve voltage quality and improve the wattless power compensation. This article embarks from the reality, put forward to strengthen the low voltage power network voltage quality and wattless power compensation equipment operation management measures, to ensure the safety of power equipment, reliable and economical operation.
1 wattless power compensation defined
(1) without reactive power compensation (referred to as the wattless power compensation), in the electronic power supply system to improve the grid power factor, lower power supply transformer and transmission line losses, improve power supply efficiency, improve power supply environment. Therefore, no reactive power compensation device in a very important position in the power supply system. Reasonable selection of compensation device, can minimize the network loss brown, improve power grid operation quality. Conversely, if the selection or improper use, may cause the voltage fluctuation in power system, harmonic wave and so many influence.
(2) low voltage without parallel capacitor device, dry-type reactor or rough leaching reactor equipment of high voltage reactive power compensation equipment including 35kV and l0kV.
(3) high voltage shunt capacitor device (referred to as the capacitor device) include: capacitor, series reactor, discharge coil, surge arresters and grounding switch equipment.
(4) dry-type reactor include: according to the grid method can be divided into shunt reactor and series reactors; reactor has no core according to can be divided into air core reactor and the reactor with iron core.
(5) the oil-immersed reactor includes: according to the reactor connected to the grid method can be divided into shunt reactor and reactor.
The traditional 2 wattless power compensation
2.1 low individual compensation
According to individual needs no power to electrical equipment, the single or multiple low voltage capacitor group scattered with electric equipment is connected with electric equipment, it uses a set of circuit breaker. The control, protection device and the motor simultaneously switching. Random compensation is applied to compensate individual large capacity and continuous operation (such as a large and medium asynchronous motor) yuan power consumption, to fill the field without power. Low individual compensation with less investment, small space occupation, easy installation, configuration is convenient and flexible, easy maintenance, low accident rate. Operation of electrical equipment, wattless power compensation input; electrical equipment outages, compensation equipment back out, it will not cause no power transmission. The installation of this compensation equipment, to select the load equipment fixed.
2.2 low-voltage centralized compensation
Low-voltage centralized compensation refers to the low voltage capacitor through a low pressure switch connected transformer low voltage side in distribution, with no power compensation switching device as the control protection device, according to the load without power busbar on the direct control of the capacitor switching. Capacitor switching is the whole group, do not smooth adjustment. The advantages of low-voltage centralized compensation: simple wiring, maintenance workload is small, so that no power balance on the spot, so as to improve the utilization rate of distribution transformer, decrease network loss, high efficiency, is currently no common means of reactive power compensation in one.
2.3 high concentrated compensation
The high voltage capacitor group is installed in the factory substation 6-10kV mother line, this method of compensation can compensate the 6-10kV bus of all lines without power, and the line of the bus has not been without compensation, the compensation compensation economic effect is poor, but the investment of this compensation method is less, easy centralized operation and maintenance, and no power on HV side of plant effective compensation of wattless power plant to meet the power factor requirements, application in some large and medium-sized factories of more general.
3 wattless power compensation principle and method
(1) power wattless power compensation principle is: overall planning, rational distribution, dispersion compensation, local balance.
(2) compensation mode without power grid: centralized compensation combined with dispersed compensation, mainly to the dispersion compensation; high pressure compensation and low voltage compensation combination, with low compensation for loss reduction; pressure and combination, mainly by reducing loss; static compensation and dynamic compensation combination, based on dynamic compensation.
(3) the power factor requirements: ① 220kV and below voltage substation main transformer in the two side power factor should be 0.90 and above. ② every 10 kV power line should be in 0.90 and above. ③ 1kVA and above capacity for the two sides of the transformer power factor should be 0.9 and above. The agricultural users distribution transformer low voltage side power factor should be 0.85 and above.
(4) the determination of reactive compensation capacity: 35kV and above substations in principle, only the main compensation reactive power loss of transformer, and consider leaving a certain margin compensation, can be compensated for by the main transformer capacity of 10% - 30%. The 10 kV distribution transformer capacity in 1 ~ kVA and more users, must carry on the element of reactive power compensation, and adopts the dynamic compensation device of automatic switching, the compensation capacity is determined according to the character of load.
The 10 kV distribution line according to the load without power take the dispersion compensation and dynamic compensation by way of compensation. ④ 5kW and above the AC asynchronous motor should be done in random compensation, the compensation capacity of 20%-30% motor rated capacity.
Operation and management 4 wattless power compensation equipment
4.1 to establish and improve the wattless power compensation equipment operating procedures
(1) no reactive compensation equipment commissioning new, expansion, renovation of the former, should according to the wattless power compensation equipment use and management system, written or revised site operation procedures, and perform the audit, approval procedures, to form an effective system.
(2) without reactive power compensation equipment operating procedures should be periodically reviewed, revised and perform the formalities of examination and approval.
(3) to establish and perfect the wattless power compensation equipment account and technical documents, technical data file should include at least the following data: equipment manufacturer specification and qualification certificate; installation and handover information: transformation, maintenance record or report completed and launched the programme; calendar year equipment preventive test reports; record emergency, major. Land, transferring equipment occurred.
Operation and management 4.2 wattless power compensation equipment
(1) capacitor device: capacitor switching should be based on the curve of voltage or range timely inputs or excision, and gradually realize the automatic control mode. Capacitor device installed before operation, in addition to the test and according to the general patrol inspection of the project, should also check the discharge circuit, protection circuit, ventilation device should be good. Each capacitor frame type capacitor devices should be numbered. At rated voltage closing impact 3 times, each time closing time interval is 5 min, the capacitor residual voltage after release can be used only for the next closing. Packet switching of capacitors, no resonance (try to cut out in the light load); capacitors on the mixed reactor should first reactance value, and reactance value small, cut on the contrary. Capacitor device allows a long running in no more than 30% of the rated current situation. Unbalanced three-phase current should not exceed +-5%.
(2) dry-type reactor: each shunt reactor as a unit. Series reactor is under the shunt capacitor unit management. For dry reactor and its electrical connection portion of each quarter should be charged of infrared temperature measurement and irregular point temperature measurement. Outdoor on reactor surfaces should be cleaned regularly, within 5 years to spray water repellent insulating material.
(3) the oil-immersed reactor: the reactor top oil temperature is often more than 85 "C", "C" shall not exceed a maximum of 95; manufacturing plant has provided the reference to the provisions of the manufacturing plant. When the reactor was a serious lack of land (such as cooling device does not operate normally, serious leakage Bo, local overheating phenomenon, dissolved gas analysis results abnormal lakes) or insulated with weakness, should not be more than the rated current operation. For long-term storage of the reactor, if valid for more than half a year, we should save oil, and regularly check the sealing condition and oil cycle test.
(4) the insulating oil: oil especially added berth shall determine the oil sources and grades in order, the acceptance of qualified before use. It is strictly prohibited to use a mixture of different species or different use oil. Need to add oil, use as far as possible the same turbulent source, the same grade of qualification berth, when necessary do first mixed mooring test confirmed feasible rear can add. Insulation dielectric loss factor both exceed the standard should be oil or oil processing. For rough treatment of Xuan to insulation rough processing numerical to lower dielectric loss causes, fully drop Xiong after the injection of new park. If the rough dielectric loss factor and dielectric loss factor also exceed the standard body exceed the standard or approaching ultra value, insulation resistance decreased significantly, in addition to the rough handling, also to the reactor body drying process.
(5): fixed casing casing, the pressure foot force should be uniform, the outside surface should be no damage, creepage trace, flashover phenomenon; reactor winding and sleeve must be reliable connection, to prevent local overheating; reactor in the oil, gas Kong Xuchong casing divided deflation.
(6) thermometer (temperature measuring device): reactor should be a thermometer measuring top oil temperature, if the instructions had been to a pointer, the highest temperature is installed, it must be the pointer in the position overlapping and display real-time temperature. Reactor must be regularly check and record the reactor temperature. To ensure that the site thermometer indicates temperature control, temperature display, temperature monitoring and control system for the three basic consistent, the error is not more than 5 "C". Thermometer should note some reactor nur.
(7) the conservator: diaphragm type oil conservator is pressed in between, storage cabinet, is easy to appear the phenomenon of oil leakage, when the pressure in the oil storage tank, easy access to air and water, the runtime must strengthen surveillance. Ferromagnetic rough meter display diaphragm type and the main methods of the capsule type Chu Xiong cabinet turbulent one, magnetic level gauge by mechanical conversion and transmission to realize ì T, should periodically check the actual level, prevent the emergence of the phenomenon of false berth. Glass tube level meter should be turbulent gas capsule and glass tube fully discharged, to prevent the emergence of the phenomenon of false oil level. To ensure that the pipeline connected diaphragm and capsule and atmospheric flow should be in operation.
(8) the moisture absorber: moisture within the silica gel should adopt the same color gel. When the number of silica gel to damp discoloration, need to replace the silica gel. Silica gel of a single color, moisture gel should not exceed 2/3. Should monitor the moisture absorber seal is good operation, when the moisture inside the upper gel first color, can determine the seal is not good. Xiong amount injected moisture absorber oil cup to moderate, too little will affect the effect of purification, too much will cause respiratory risk when bo.
(9) the valve: the valve must be based on actual needs, in the closed and open positions. Usually rotate the handwheel counterclockwise, clockwise direction between the door open; close the door. If the width of the door side with the atmosphere (such as heavy valve, spare valve), valve on the air side of the seal plate and gasket seal. Installation of Fujian door, should pay attention to the direction of the arrow body and oil remains in the same direction. Cast iron ball valve spool position such as oil leakage in the operation, must be timely processing or a combination of maintenance replacement valves. Butterfly valve in the opening and closing operation room door, should be fixed measures to do a good job spool position.
5 Conclusion
With the rapid development of social economy, electric power enterprises to better meet the increasing customer demand for electricity services at the same time, but also for the more comprehensive management of user, network monitoring, in the process, will continue to have new technology, new equipment development and application, not to idle compensation technology will be more economical and effective.