As a kind of power converter, inverter main circuit (rectifier and inverter) is the power circuit, in normal circumstances, the voltage in the circuit will reach 100 volts or more, the current will reach several amperes or even higher. The integration degree of the frequency conversion speed control system is becoming larger, the integrated volume becomes smaller, the function becomes stronger and the performance is stable.
1, microelectronics technology integrated motor speed control system
1.1, problem solving
The integration testing process of integrated motor variable frequency speed control system application of microelectronic technology in pressure and isolation, control circuit and power circuit interface, thermal effect, magnetic technology and circuit, the following describes technical scheme of integrated motor speed control system application of microelectronic process.
1.1.1, voltage and isolation
In the speed control system, high voltage circuit not only are also part of the low part, but in a semiconductor integrated circuit, silicon conductive, so as to prevent electrical connection between devices, must be with the isolation of the circuit elements, if not isolated, there will be additional small current, the power consumption of the power IC the greatly increased; at the same time, the high voltage will transfer to the low voltage circuit, device transfer process may breakdown voltage circuit. In order to avoid the occurrence of the above, in the power integrated circuit can select NP junction isolation technology, charge control isolation technology, dielectric isolation technology, micro crystal base isolation technology and corrosion - filled isolation technology to realize electrical isolation.
1.1.2, control circuit and power main circuit interface
In general the motor speed control system, control circuit and power circuit interface by a special driving circuit chip or by transformer isolation drive circuit, driving power supply most of the multi-channel isolated power supply. However, in the application of micro electronic technology in the frequency conversion speed regulation system, at present, it is impossible to integrate the inductor into the chip, and can not provide the isolated power supply.
1.1.3, thermal effect
The key problem to be solved in the application of microelectronic technology in the process of the variable frequency speed regulation system is the thermal effect. It is not only because of the switching and conduction losses in the main circuit, but also because of the thermal resistance of the chip package. In the case of the chip temperature rise, will lead to deterioration of circuit performance parameters, and ultimately reduce reliability. If we want to solve the problem of thermal effect effectively, we should start from various aspects, such as circuit topology design, layout design and packaging technology.
Integrated detection of 1.1.4, magnetics and circuits
(1) MOS power integrated circuit. MOS integrated technology can be divided into high voltage CMOS and D/CMOS technology, the former is usually used in the switching process, as shown in Figure 1, figure 2, respectively, the double deep and shallow depression high pressure CMOS profile.
The former can be compatible with CMOS bipolar technology, which can be used in the process of high pressure and low pressure MOS standard the same CMOS technology. DMOS technology usually has self isolated D/CMOS, junction isolated D/CMOS and isolated complementary D/CMOS integrated technology.
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(2) BIMOS integration technology. In the process of power integration, the application of BIMOS integration technology is more common, according to the actual situation of the junction isolation, can be divided into thick epitaxial and thin epitaxial BIMOS integration technology. The production of thick epitaxial layer, high voltage output tube is usually LDMOS or VDMOS, this technique can be integrated by high voltage LDMOS, high VDMOS, low NPN and low PNP and low CMOS; the latter was produced in the thin epitaxial layer, the high voltage output tube for RESURF devices, voltage BIMOS integrated technology can get higher.
(3) SMART power integration technology. SMAR power integration technology, through planar technology, has integrated technology for power integrated circuits. At this stage, the use of power integrated devices is more common. Its name is SMART power integrated device, which is a kind of intelligent power / high voltage integrated circuit.
MOTOLA SMART integrated power device output by epitaxial base vertical PNP transistor, the collector device for the position of the back of the chip, substrate with low resistivity p+, the 15A RCE is 70MW; logic circuit selection of Lv Shan CMOS, made in n- epitaxial layer, CMOS without longitudinal and transverse isolation, can realize self isolation. Switch select PNP transistor electrode in the open state is in the positive bias and the injection, so the isolation between high voltage PNP transistor and low circuit is essential, through the p+ isolation diffusion to achieve the penetration of the n- epitaxial layer. In the T-MOS power transistor, T-MOS can be hung silicon rectifier, high current regulator and other fields SMART power integrators can be used.
1.2, the feasibility of the application of microelectronic technology
In the range of small power range, it can be realized by using the micro electronic technology to realize the motor frequency conversion. Subject to the current level of microelectronics technology and the characteristics of this process, at this stage in the integrated motor speed control system in the application of micro electronic technology is limited to a small range of power.
2, conclusion
In recent years, driven by the rapid development of electronic information industry, the development of microelectronics technology has changed dramatically, and various types of control chips are constantly emerging. At the same time, with the development of microelectronics technology, the high voltage integrated chip will gradually mature and develop.
Reference
[1] Xu Bing. Research on variable frequency energy saving control system of hydraulic elevator using accumulator [D]. Hangzhou: Zhejiang University, 2011
[2] Hu Changsheng. Research on the integrated technology of variable frequency speed control system [D]. Hangzhou: Zhejiang University, 2012
[3] Cui Bowen. Research on fault detection and diagnosis of motor speed control system [D]. Xi'an: Northwestern Polytechnical University, 2012
[4] Cheng Sixue. Based on the study on the integrated control method of PLC and frequency converter and its application [D]. Shenyang: Shenyang University of Technology, 2015