Because along with our country national economy’s development and the people’s material culture living standard’s unceasing enhancement, the air-conditioner has widely applied in society’s each kind of situation, the direct-current frequency conversion air-conditioner has the energy conservation, lowly chirp, the constant temperature control, all-weather revolution, the start low-frequency compensation, to achieve performance fast and so on hypothesis temperature, makes air conditioning’s comfortableness to enhance greatly, will receive people’s affection more and more. The monolithic integrated circuit technology’s widespread application, the direct-current frequency conversion technology and the fuzzy control technology in the air-conditioner embedded control domain’s success application, the semiconductor power component’s rapidly expand have provided the technical support for the direct-current frequency conversion control’s promotion.
This design proposal’s AC frequency conversion air conditioning controller by the indoor machine controller, the outdoor machine controller two parts is composed. Based on the SPMC75F2413A high performance, designs the outdoor machine AC frequency conversion controller with it, easy to realize the product modulation, the intellectualized characteristic, the controlled variable uses the open style structure, is advantageous with each kind of compressor joint, can thus act according to the different factory the request to carry on the product in the shortest time turning to a new generation. By this way, the product may push to the market quickly, obtains in the time the competitive advantage. Below this controller includes the key technologies:
1st, fuzzy control technology: Is warm based on the room inner rim, the tube is warm, the room outer ring is warm, the tube is warm, compressor parameter establishment fuzzy logic relations and so on discharge temperature, compressor over-load protection temperature, compressor electric current, control compressor’s operating speed, the outdoor air blower and other load movement;
2nd, the highly effective triple frequency pours into based on DDS SPWM has the technology, using the supply voltage, the precise frequency control, the real-time voltage makes up fully tastes the function, causes the compressor effective work;
3rd, modular control protection circuit: When the module has the guard signal output, separates the PWM module output control signal through the hardware circuit, achieves the protection module the effect, and reliable gives the monolithic integrated circuit module guard signal;
4th, EMC and reliability design technology: In grasps under air conditioning’s disturbance mechanism’s premise, the hardware design key considers the following several points: Power circuit design, filter circuit parameter design, board grounding and holding wire design, and the software uses the fault-tolerant technology.
2 System overall concept introduction
In this AC frequency conversion air-conditioning system locellus machine system and outdoor machine system two parts, the indoor machine system is mainly system some logic status messages processing, but the outdoor machine system is mainly compressor’s frequency conversion actuation part. Machine selects what in this system plan median cell is SPCE061A realizes, SPMC75F2413A is mainly the application in the frequency conversion actuation part. Therefore the indoor machine system no longer relates in detail in this. Outside machine circuit structure diagram like chart 2.1.
This system’s key job flow:
Outside machine master control MCU (SPMC75F2413A) momentarily receives from the indoor machine control and the status messages, thus controls the outdoor air blower, the four-way valve and the compressor, completes the corresponding control function. Simultaneously also feeds in the outdoor machine some conditions and the outdoor some temperature information indoor machine. Supplies indoor machine to make control.
3 System hardware design
System circuit schematic diagram like chart 3.1. And the PS21865A three-phase power entire bridge electric circuit module, uses for to realize the PWM signal power synthesis, thus actuates the compressor. ULN2003A is the collecting electrode opening output power reverser, mainly uses for in driving system’s relay, thus controls the air blower and the solenoid valve. SPMC75F2413A monolithic integrated circuit’s leading role: 1. According to indoor machine command control overall system. 2. Completes the AC frequency conversion compressor’s frequency conversion driving signal production and the control function.
Figure 3.1 Power_Line is one kind of half-duplex electric current link transfer network, it is mainly uses the power source and a special-purpose order wire, enables indoor outside to constitute an electric current link, the electric current link by the indoor machine power supply. This electric circuit for indoor outside machine provides a correspondence return route. The SPMC75F2413A synthesis pours into the triple frequency the SPWM signal after the IOB0~5 output, separates after the cushion and the light inputs PS21865A, then output control electrical machinery. SPMC75F2413A IOB6 detects the input end wrongly, through feeds in the signal to it the examination, once PS21865A presents the work exceptionally (for example pressure, undervoltage, overflow, overheated), will actuate the hardware to forbid PS21865A to work immediately, simultaneously will apply for the interrupt, will request the CPU processing. IOA0~3 is the simulation input port, is mainly the temperature sensor connection and the direct-current high pressure survey connection. IOC8~10 is controls the four-way valve and outside air blower’s control.
The click looks at the original map
Figure 3.1 system circuit schematic diagram
4 System software design
The entire outdoor machine system software mainly includes two parts: 1. With indoor machine correspondence, coordination control part. 2. The outside machine compressor actuates the control section.
The system with the indoor machine correspondence, the coordination control part mainly includes the serial port interrupt servicing and orders the explanation execution and the main loop control and so on several parts. And master control flow like chart 4.1. The serial port interrupt servicing is mainly the receive from the indoor machine data packet, and carries on processing to the corresponding information, guaranteed that passes to the control procedure the order and the data accuracy; The order explained that the operative paragraph mainly explains the indoor machine order, and carries on corresponding processing.
Figure 4.1 main flow
The compressor actuates the control section to divide into the SPWM signal synthesis, the electrical machinery to add the retarded control, the electrical machinery to stop the service and so on several parts. And what most core is the SPWM signal synthesis. This system’s profile synthesis uses DDS (direct digital frequency synthesis) the way carries on. This part is mainly composed of the PWM periodic table interrupt servicing and the corresponding auxiliary computational procedure. And the PWM cycle interrupt servicing is the signal synthesis hard core, in the overall system it takes 70% about the operand. It mainly completes the actuation profile the synthesis and the skeleton line voltage tendency makes up tastes the function, simultaneously the cyclical interrupt is DDS provides the clock datum; But adds the retarded control part main track establishment frequency, thus enables the acceleration which the current operating frequency establishes to the goal operating frequency to approach; The electrical machinery stops the service is mainly starts and stops these two to the electrical machinery special and carries on the special handling.
Because the PWM cycle interrupt service carries out the frequency to be very high (about 5KHz), therefore this part of use assembly compilation, guaranteed that as far as possible small CPU resources take. PWM interrupt servicing subroutine flow like chart 4.2.
Figure 4.2 PWM interrupt servicing subroutine flow chart
5 Conclusion
Usually, in the development frequency conversion equipment’s process, needs to compile timely, the procedure readability strong code, by now needed to use the mix programming. But Ling Yang’s m’nSP™ IDE has the good programming environment, it may be very relaxed, carry on the mix programming (to transfer assembly program easily in the C procedure, transfers the C procedure in assembly program).
This system has used SPMC75F2413A two timer peace treaty 17 IO mouth resources, actually the SPMC75F2413A resources are quite rich. Because it has the specialty frequency conversion hardware support, the frequency conversion system development becomes relatively simple. At the same time, SPMC75F2413A has the quite outstanding performance in the frequency conversion control aspect. Therefore, based on the SPMC75F2413A frequency conversion system in general frequency conversion domains and so on frequency conversion, frequency conversion electrical appliances has the broad application prospect.
