Power dissipation control circuit, intelligent power module and variable frequency household appliance

Abstract

The invention provides a power dissipation control circuit, an intelligent power module and a variable frequency household appliance. The power dissipation control circuit comprises a low power dissipation switch element and a switching control module, wherein the low power dissipation switch element is connected to any IGBT in the intelligent power module in parallel to form a switch assembly, the switching control module is connected to a control chip corresponding to the intelligent power module to detect the duty ratios of control signals output by the control chip within two adjacent periods and calculate the difference value of the duty ratios of the control signals within the two adjacent periods, under the condition that the difference value of the duty ratios is larger than or equal to a preset threshold value, the IGBT and the low power dissipation switch element are in the working states at the same time, and under the condition that the difference value of the duty ratios is smaller than the preset threshold value, only the low power dissipation switch element is in the working state. By means of the technical scheme, different on-off devices can be adopted when the difference value of the duty ratios of input signals within two adjacent periods is changed, power dissipation of the intelligent power module is easily reduced, and the risk that the on-off devices are broken down by the overcurrent is avoided.

Description

technical field [0001] The present invention relates to the technical field of power consumption control, in particular to a power consumption control circuit, an intelligent power module and a frequency conversion household appliance. Background technique [0002] Intelligent Power Module, or IPM (Intelligent Power Module), is a power drive product that combines power electronics and integrated circuit technology. The intelligent power module integrates the power switching device and the high-voltage driving circuit, and has built-in fault detection circuits such as overvoltage, overcurrent and overheating. On the one hand, the intelligent power module receives the control signal of the MCU (Micro Control Unit, micro control chip) to drive the subsequent circuit to work, and on the other hand, it sends the system status detection signal back to the MCU. Compared with the traditional discrete solution, the intelligent power module wins more and more markets due to its advan...

AI Technical Summary

Problems solved by technology

[0029] For the state of low-frequency operation of the compressor, it is often desired to obtain low power consumption. When using IGBT tubes as on-off components, due to the tailing effect of IGBT tubes, the switching loss of the on-off components cannot be very low, so that the smart power The loss of the module 100 cannot be made very low

[0030] If the IGBT tube is replaced by a non-smearing MOS tube, the on-off loss and system power consumption can indeed be reduced when the compressor is working at low frequency, but due to the limitation of the current capacity of the MOS tube, when the compressor enters A large current will exceed the current range that the MOS tube can withstand, causing the MOS tube to burn out due to overcurrent, and even cause a fire in severe cases

[0031] In the related technology, the low-frequency operating loss of the intelligent power module is reduced by improving the tailing effect of the IGBT tube. However, this special process makes the production cost of the IGBT tube very high, and is not suitable for popularization in civilian fields such as frequency conversion air conditioners.

[0032] Therefore, how to reduce the loss of the intelligent power module when it works at low frequency and avoid the risk of overcurrent when it works at high frequency, and how to make the production cost suitable for civilian use has become an urgent technical problem to be solved.

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