Mitsubishi inverter air conditioner basic principle training

Mitsubishi inverter air conditioner basic principle training

1. The difference between inverter air conditioner and fixed frequency air conditioner

　　 1. Different compressors

　　 The operating frequency of the compressor of the fixed speed air conditioner is not variable. (50Hz) The operating frequency of the compressor of the inverter air conditioner can be changed. (10Hz~140Hz)

　　2, the controller is different

　　The controller of the inverter air conditioner is far more complicated than the fixed speed air conditioner;

　　3, the output capacity of the air conditioner is different

　　 In the same working condition, the fixed speed machine has only one output capacity; the output capacity of the frequency converter is a range;

　　 4. Different comfort

　　The comfort of the inverter air conditioner is better than that of the fixed speed air conditioner; it can be cooled quickly or heated with less temperature fluctuation;

　　 5. Different electricity consumption

　　In terms of long-term operation, inverter air conditioners will save more than 30% of electricity than ordinary air conditioners; however, frequent turning on/off of inverter air conditioners cannot save electricity.

　　6, the compressor works differently

　　 The compressor of the fixed-speed air conditioner is powered by mains, and the frequency and voltage are fixed. When the fixed frequency machine detects that the ambient temperature reaches the set temperature of the air conditioner, the compressor will stop directly; (the shutdown rule follows the -2+6 principle, that is, the cooling mode is 2 degrees below the set temperature, and the heating is 6 degrees above the set temperature) When the ambient temperature of the air conditioner exceeds the set temperature, turn it on again; the compressor power supply of the inverter air conditioner is a three-phase AC power with adjustable frequency after the inverter module inverts the mains. The inverter air conditioner detects the ambient temperature After reaching the set temperature, the air conditioner first enters the frequency reduction mode, and enters a stable state when the environmental heat dissipation and air conditioning cooling capacity balance are reached during the frequency reduction process; when the inverter air conditioner is reduced to the minimum operating frequency, the air conditioning cooling capacity is still greater than the environmental heat dissipation capacity, then Inverter air conditioners will also shut down;

　　 2. The basic principle of frequency conversion controller

　　 1. In terms of energy conversion, frequency conversion control can be divided into AC to AC frequency conversion and AC->DC->AC frequency conversion.

　　2. Regarding the frequency conversion control of household appliances, whether it is AC frequency conversion or DC frequency conversion, the frequency conversion operation is realized through AC->DC->AC.

3. AC->DC->AC realization diagram: To get AC with adjustable frequency, first rectify 220V AC mains power into DC, and then change DC into AC with adjustable frequency, thus completing the frequency conversion process ,As shown below:

　　 3. Classification of inverter air conditioners

　　1, AC inverter air conditioner (BP):

　　By changing the power supply frequency f of the AC compressor, the speed of the compressor is controlled;

　　2, DC inverter air conditioner:

　　Mei’s inverter air conditioners are currently all DC inverters; in terms of the overall form, DC inverters can be divided into full DC inverters (BP3) and DC inverters (BP2);

　　3. Full DC inverter air conditioner (BP3):

　　Compressors, indoor and outdoor fans use DC brushless motors, and DC frequency conversion means that only compressors use DC brushless motors.

　　4. The origin of the name of DC frequency conversion:

In household appliances, DC frequency conversion is the most commonly used (and has always been used) brushless DC motors. In order to distinguish this type of frequency conversion from AC frequency conversion, people are accustomed to refer to the frequency conversion household appliances using brushless DC motors as DC Frequency conversion household appliances; like electronic expansion valves and fluorine-free air conditioners, DC frequency conversion is a conventional term. This naming method is somewhat misleading; therefore, DC frequency conversion does not mean that the compressor is powered by DC power. Its conversion method is AC frequency conversion is the same as AC-DC-AC. The voltage supplied to the compressor is still an AC signal.

　　 Fourth, the advantages of DC inverter air conditioners

　　 1. High operating efficiency;

　　 2. The compressor has good speed regulation performance;

　　3, the compressor speed range is wide;

　　4. The compressor motor has a large operating torque;

　　5. The air conditioner has low operating noise;

　　6. ​​High energy efficiency ratio of air conditioner (compared with AC);