Application scope, characteristics and analysis of frequency conversion cabinet
Frequency conversion cabinet, ordinary power cabinet or control cabinet is changed from traditional driving mode to frequency conversion driving mode. In short: use frequency converter to drive the control cabinet of power unit. Because of its good starting performance, speed regulation performance and energy-saving effect, it has become a popular power driving mode.
1. It is widely used in various types of tap water supply systems in urban and rural areas.
2. Constant pressure control of water supply for high-rise buildings, domestic water, fire water and closed-loop water under industrial production conditions.
3. Automatic control of boiler make-up pump and thermal heating circulating pump.
4. Farmland irrigation and fountain control.
5. Air conditioning system and cooling circulating water control.
6. Secondary pressurization control of flow system of water plant, pump station and petrochemical industry.
7. Tslb frequency conversion cabinet can be used for various motor control cabinets requiring energy-saving transformation or 0-speed starting production line.
High efficiency and energy saving can be seen from the motor formula. The power consumption of the system motor is cubic with the motor speed. When the pressure is constant, the water output of the pump is directly proportional to the motor speed. The equipment adopts the constant pressure working mode. When the water consumption is reduced, the system maintains the constant pressure of the pipe network, reduces the water supply by reducing the number of pump revolutions, and reduces the power consumption according to the cubic characteristics. For example, the water supply is 80% of the rated value, the motor energy consumption is 51.2% [(0.83)] and the power saving is 48.8%. Considering that the power saving rate of the actual system is lower than the theoretical value, it is still considerable.
Functions of frequency conversion cabinet:
The high-power frequency conversion cabinet can minimize the impact of high-power water pump / fan on the power grid and the voltage drop of the first mate, with remarkable power saving effect.
As an early commodity, general frequency converter has been listed in China for nearly a decade. Its sales have increased year by year. There is a market of more than billions of yuan (RMB) this year. Among them, most of them are imported brands, with power ranging from 100 watts to thousands of kilowatts; Simple or complex functions; Low or high precision; Slow or fast response: PG (tachometer) or no PG; Noise or no noise, etc.
For many users, it has been updated many times in the past decade. Most of the frequency converters used now belong to the most advanced models. From the perspective of application, our level is no different from that of developed countries. As a domestic manufacturer, through the marketing of foreign advanced technology in the past decade, it is also actively developing domestic frequency converters and trying to catch up with the level of developed countries in the world.
Reviewing the development of foreign general frequency converter technology in recent ten years is of great positive significance for deeply understanding the trend of AC drive and control technology and how to stand at a high starting point and develop our own products in combination with China's national conditions.
Design considerations of frequency conversion cabinet:
1) Heat dissipation problem: the heating of the frequency converter is caused by internal loss. The frequency converter must be cooled. We usually use a fan to dissipate heat.
2) Electromagnetic interference: when there are high-frequency impact loads in the system, such as electric welding machine and electroplating power supply, the frequency converter itself will be protected due to interference.
3) Service environment of frequency conversion cabinet: waterproof, anti condensation, dustproof and anti-corrosive gas.
Function of frequency conversion cabinet:
1) Control the operation of the motor;
2) Variable frequency power supply shall be provided to the motor to change the speed of the motor.