Guangzhou Guanggao High Voltage Electric Apparatus Co., Ltd

Our company provide 330kV oil-immersed power transformer ,with capacity of 360MVA and below. The transformer is based upon world-wide advanced technology and also incorporates the experiences of internationally leading transformer companies as well as our own long-term experiences. Low loss, low partial discharge and high short circuit withstand capability series transformers are achieved through innovation and optimization. Our transformer conform entirely with latest national standard GB1094.1~2-1996, GB1094.3-2003, GB1094.5-2003 and international standard IEC-76. Outstanding features as follows: 1. Low loss, low noise The core laminations are composed of imported high quality grain-oriented cold-rolled silicon steel sheets with chamfered joints and the joints are step-lapped with 5 steps, thus ensuring low loss and low noise. The inside of the tank is lined with magnetic and copper shields, measures have been take for metallic structural pares located in high magnetic field, to deduce stray loss and thereby the total load loss, and to relieve local overhearing. Performance standard of 330kV class transformers which designed and manufactured by our company, can reach GB 10-type or GB11-type, and the noise is much lower than GB. 2. Safe and reliable service Reliability is the everlasting objective of our company, partial discharge of finished products are constantly kept below 100pC, ensuring that the transformers can be operated under long service voltage and occasional over-voltage without trouble. Low current density in winding conductor and appropriate cooling arrangement ensure that the winding temperature rise and top oil temperature rise are lower than that specified in the national standard by more than 5K and that the mechanical stress in winding conductor during short circuit does not exceed certain safe limit. Together with technological procedures during manufacture and other means to elevate mechanical strength, transformers can withstand server short circuit in all case during service. 3. Easy erection and maintenance To minimize erection work at sit, transformers are so fabricated that lifting the active part out of the tank for inspection after arrival at sit is not mandatory. Beside, all components to be mounted on the transformer at site have been preassembled before dispatch, and all secondary wirings have been laid down into conduits on the transformer and connected to the terminals in the control cabinet or terminal box. Natural oil circulation and forced air cooling (ONAF) are generally adapted in our 180kV class transformers below 240MVA. 70% nameplate rating can still be achieved in case the fans are out of service. Little maintenance work is required for the cooling devices. 4. Careful fabrication Vertical winding machines with tension device are used for winding, so that the windings can be wound more tightly and therefore mechanically strength as a whole. All insulation parts subjected to mechanical stress during short circuit, such as spacers in windings are made with T4 densified pressboard to deduce shrinkage. Drying process for the windings are carried out twice, once for ht individual winding, and again for the assembled phase block. After core and coil assembly, an additional vapor phase drying (VPD) is once more carried out to ensure that all insulation parts are thoroughly dried and no further shrinkage is possible to occur during service. All the high voltage terminals and nearby metallic structural parts are rounded up to prevent partial discharge. High voltage bushing terminals are contained with turrets, and kept concentric with the turret. All the leads are properly crimped and metallized to be rounded up. VPD process insures that the moisture content within the transformer is kept at a very low level, and the core and coil assembly is once more cleaned by condensed vapor flowing down the surfaces. The fabricated tanks are relived from welding stress and shot-blasted integrally, so as to be free form oil leakage trouble and to give the tank a clean, pleasant looking appearance. fumigation wooden case

Rectifier transformer is a transformer which used as the source of rectifier equipment. And primacy side of rectifier transformer connected with AC power is called line side, and secondary side connected with rectifier is called valve side. Our company use the advanced techniques and manufacturing process, and with domestic colleges and universities to develop a number of research projects. Using procedural design, insulation breakdown mechanism, the electric field numerical analysis and insulation technology, the impact of characteristics and anti-sudden short-circuit strength of winding, the loss of eddy current filed calculation are analyzed and calculated. With manufacturing experience on rectifier transformer for many years, our company has got major break-though on the basis of the traditional calculation, which will further improve the reliability and advancement of products. Features about rectifier transformer: 1.The rectifier transformer load is non-linear impedance, and valve side windings of rectifier transformer would get the currents which contain fundamental and other high-order harmonic superposition. And line side also gets corresponding non-sinusoidal currents connected by rectifier circuit coupling method. 2.According to different requirements of various customers, the valve side of rectifier transformer has a variety of special coupling method, such as: dual-back-star with inter phase reactor, three-phase bridge, star-delta parallel, six-phase bridge by inter phase reactor. 3.To improve power factor and reduce the line side harmonic currents of high-power rectifier equipments, rectifier transformer is needed to use star-delta winding phase displacement, phase-shift windings by phase displacement, autotransformer phase displacement, to improve the number of pulse of rectifier equipment. 4.According to the user¡¡¥s process requirements, the rectifier transformer line side voltage is required (such as 220kV) straight down to a very low valve side voltage (such as 1kV). The valve side voltage of rectifier transformer is required within a wide range of on-load tap from 5% - 105%. Auto voltage regulator and main theme of unity, string variable voltage regulator and other ways are used in rectifier transformer to achieve the purposes of a wide range voltage. 5.Self-saturable reactor can be used to change over and stabilize voltage in order to smooth rectify voltage. And some use silicon control to regulate voltage. 6.Valve side current of high-power rectifier equipment is very large, reaching 100kA and even greater. To improve power factor and avoid partial overheating and uneven distribution of current rectification components, it¡¡¥s required the technology of reverse-phase parallel. 7.With the wide application of AC frequency control technology, newly developed three-crack drive rectifier transformer came into being. And the lower voltage valve side of this transformer cracked into three independent branches, which can be made to supply for three different load power, which achieve ¡¡ã multi functional ¡¡À effect, reducing loss and saving area. 8.In order to reduce the large current in the fuel tank and other structures caused by loss, the rectifier transformer used magnetic shielding technology and so on. A number of 220kV and below and different kinds of rectifier transformers have been manufactured for the general industrial, electrochemical electrolysis, transmission, traction frequency, variable frequency power supply, DC power transmission and other industrial sectors over ten years, and got the user¡¡¥s high praise. Recently, the 220kV level on-load-tap rectifier transformers supporting the country¡¡¥s largest 600 thousand project of caustic soda is done, and got the high praise of users. fumigation wooden case

Supplier: Japanese quality switchgear components, breakers, magnetic contactors, switches, pilot lights, pushbuttons, panel instrumentations, power management meter, protection relays, transformers, inverters, ups.

Transformer up to 33 kv & 10 mva ratings Depending on customers requirement