Application of DC Disconnect Switch

Application of DC Disconnect Switch

The DC isolation switch is a device to prevent the AC and DC short circuit of the DC isolation switch. It is connected with an isolation transformer between the power input terminal of the AC motor power supply switch cabinet and the three-phase AC power input line and the input of the three-phase AC power supply. The cable is connected with the primary winding of the isolation transformer, and the secondary winding of the isolation transformer is associated with the power inlet end of the AC motor power supply switch cabinet.

The DC isolation switch solves the problem that in the control system of the DC isolation switch in the prior art, the insulation strength of the insulator is reduced due to the damage of the insulator between the shell of the AC motor and the deceleration mechanism with DC and other reasons, or when the AC motor leaks, The resulting AC and DC short-circuit accident. It effectively protects the safe operation of power supply rectifier equipment and prevents significant economic losses and personal injury.

Scope of application

The DC isolating switch is suitable for isolation protection in lines with operating voltages up to 1000VDC and rated currents up to 100A and realizes load distribution.
Disconnection and effective isolation. It is mainly used in the photovoltaic field.
The DC isolating switch is mainly suitable for indoor installations with AC 50/60Hz, rated voltage of 1500V, the maximum voltage of 1000V, and rated current of 200A and 400A. In addition to being used for switching power supplies, DC isolating switches can also be used for infrequently making and braking circuits.

Structural features

Technical features of TX7H DC isolating switch:
The number of poles of the primary circuit of the TX7H DC isolating switch is three poles, and the operation mode is manual. The design of the button fully absorbs the advanced technology at home and abroad, has achieved good results in combination with the actual situation and technological level of our country, and has a reasonable design structure, Beautiful appearance, reliable work characteristics

Design

Compared with the original air cooling method, the 400 MW hydro-generator adopts the evaporative cooling technology; the temperature rise is reduced by 30K. As a result, the weighted efficiency is increased by at least 0.25%; that is, an extra 1000 kWh of electricity is generated per hour of operation, and the insulation life of the motor can be extended. Furthermore, more than double the extension, and on the premise that the temperature rise of the windings remains unchanged, the engine has a 10% over-generating capacity so that it will bring significant and long-term economic benefits to the power station.
The more critical significance is that the successful application of this technology enables my country to have the cooling technology of large-scale hydro-generators with independent intellectual property rights. At the beginning of the 21st century in my country, there will be many large and super large hydro-generators waiting to be developed and produced, and cooling is one of the critical technologies. Hence, the outstanding advantages of complete adaptation will be enormous, so the expected economic and social benefits.
The DC disconnect switch synthesizes electrical machinery, motor structure, engineering thermophysics, dielectric electrochemistry, and other disciplines and has a rich connotation. However, the system required to realize it on the motor is not complicated, so the application of this technology is more comprehensive. Generally speaking, the hydro-generator with a capacity of more than 200 megawatts can obtain good economic benefits by using this technology. However, there will be better results for units that frequently start (such as pumped-storage power plants) or require over-generating capacity (including capacity expansion).
 

Leave A Reply