Phone Number : +8613408630944
WhatsApp : +8613408630944
November 6, 2020
Electricity is one of the most important energy sources in modern society. A generator is a mechanical device that converts other forms of energy into electrical energy. It is driven by a water turbine, steam turbine, diesel engine or other power machinery, and converts the energy generated by water flow, air flow, fuel combustion or nuclear fission into mechanical energy and transmits it to the generator. Converted into electrical energy by a generator. Generators are widely used in industrial and agricultural production, national defense, science and technology and daily life. There are many forms of generators, but their working principles are based on the law of electromagnetic induction and the law of electromagnetic force. Therefore, the general principle of its construction is: use appropriate magnetic and conductive materials to form magnetic circuits and circuits that conduct electromagnetic induction with each other to generate electromagnetic power and achieve the purpose of energy conversion.
Generators are divided into two categories: DC generators and AC generators. The latter can be divided into two types: synchronous generators and asynchronous generators. The most commonly used in modern power stations are synchronous generators. This kind of generator is characterized by being excited by direct current, which can provide both active power and reactive power, which can meet the needs of various loads. Since the asynchronous generator does not have an independent excitation winding, its structure is simple and easy to operate, but it cannot provide reactive power to the load, and it also needs to draw a lagging magnetizing current from the connected power grid. Therefore, the asynchronous generator must be connected in parallel with other synchronous motors or a considerable number of capacitors in parallel. This limits the scope of application of asynchronous generators and can only be used in small automated hydro power stations. Before the 1950s, DC generators were mostly used for DC power supplies used in urban trams, electrolysis, and electrochemical industries. However, the DC generator has a commutator, the structure is complicated, the manufacturing is time-consuming, the price is relatively expensive, and it is prone to failure, difficult to maintain, and the efficiency is not as good as the AC generator. Therefore, since the advent of high-power controllable rectifiers, there has been a trend of using AC power to obtain DC power through semiconductor rectification to replace DC generators.