Thermal analysis of high-power high-frequency inverter

The variable frequency drive inverter is a variable speed motor to run and thus achieve the energy saving effect of the device, it is customary to the rated voltage between the motor 3kV to 10kV called high-voltage motors, it is generally for the run down the 3kV to 10kV high voltage environment of a motor development It called high-voltage inverter drive. Compared with the low voltage inverter, high-voltage inverter is suitable for high-power wind, water pump frequency control, can receive significant energy savings.
The inverter is the use of power semiconductor devices will be the role of the on-off frequency to another frequency power conversion power control device. With the rapid development of modern power electronics and microelectronics technology, high-voltage power frequency control devices continue to mature, high pressure had been difficult to solve the problem, in recent years through devices in series or series units have been solved.
Drive at a high temperature Notes:
1, carefully monitors and records all parameters of the inverter is displayed on the display unit, abnormal should immediately reflect
2, carefully monitor and record the ambient temperature frequency chambers, environmental temperature should be between -5 ℃ ~ 40 ℃. Phase-shifting transformer temperature rise should not exceed 130 ℃
3, when the summer temperature is high, should strengthen the drive to install ventilation site. Ensure that ambient air does not contain an excessive amount of dust, acids, salts, corrosive and explosive gases
4, summer is the rainy season, should prevent rainwater from entering the inverter (such as rain downwind tells air to enter)
5, filter Netcom often drive on the door should be cleaned once a week; such as work environment dusty, cleaning interval should be shortened based on the actual situation
6, the drive normal operation, a standard thickness of A4 paper should be firmly adsorbed on the door air inlet filter online
7, inverter room must be kept clean and tidy, it should be cleaned at any time according to the actual situation.
8, frequency room ventilation, lighting must have good ventilation and cooling equipment (air conditioning, ventilation fans, etc.) can operate normally.
In large-scale power electronic devices, as the temperature increases, the failure rate increases, so power high-voltage inverter power devices is directly related to the thermal design of the equipment reliability and stability. High-power high-voltage inverter often require high reliability, affecting the main form of power electronic equipment failure is thermal failure, according to statistics, more than 50% of the electronic thermal failure is mainly caused due to a temperature exceeding the rated value. From the structural design for the cooling technology is to ensure the normal operation of the key. Since the frequency converter manufacturer’s equipment tricycle power, usually MW class, during normal operation, it will generate a lot of heat. To ensure the normal operation of equipment, the amount of heat dissipated, cooling and ventilation optimization program, properly designed and calculated to achieve efficient cooling equipment, for improving the reliability of the equipment is necessary.
Cooling Calculation
High frequency inverter in normal operation, the main source of heat isolation transformer, reactor, power unit, a control system, in which the heat as the main circuit of power electronic switching devices, the power unit of thermal design and power cabinet cooling and ventilation design most important. Igbt power devices on or igct, its pn junction should not exceed 125 ℃, Package shell 85 ℃. Studies have shown that temperature fluctuations over component ± 20 ℃, its failure rate will increase 8 times.
Thermal Design Considerations
(1) selection of heat resistance and thermal stability of components and materials to improve their allowable operating temperature;
(2) reduce the equipment (devices) internal heat. Therefore, it should be more choice of micro-power devices, such as a low-loss type igbt, and minimize the number of heating components in circuit design, while optimizing the switching frequency of the device in order to reduce the heat;
(3) the use of appropriate cooling mode and with the appropriate cooling method to reduce ambient temperature, speed up the cooling rate. For more information, please visit www.rendapower.com.