High-performance three-phase variable frequency power supply solution based on SPMC75 series microcontroller

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High-performance three-phase variable frequency power supply solution based on SPMC75 series microcontroller [Copy link]

1 Introduction
　　The variable frequency power supply is a power conversion device, which has the advantages of pure output waveform, stable output voltage, adjustable output frequency and output voltage. Its good performance is widely used in the fields of sensing, instrumentation, industrial control, etc. This article mainly introduces the development of high-performance three-phase variable frequency power supply using SPMC75F2413A and IPM (PS21865A).
2 Introduction to chip features
　　SPMC752413A is a new member of the μ'nSP? series of products. It is a 16-bit microcontroller specially launched by Lingyang Technology for variable frequency drive. It has excellent performance timer and PWM signal generator group.
　　SPMC75F2413A has an operating speed range of 0~24MHz within the operating voltage range of 4.5V~5.5V, and has 2K words of SRAM and 32K words of flash ROM; up to 64 programmable multi-function I/O ports; 5 general-purpose 16-bit timers/counters (including two motor drive dedicated PWM waveform generators and two position detection interface timers), and each timer has a PWM event capture function; 2 dedicated timing programmable cycle timers; programmable watchdog; low voltage reset/monitoring function; 8-channel 10-bit analog-to-digital conversion. With the support of these hardware peripherals, SPMC75F2413A can easily realize various frequency conversion systems.
The features of SPMC75F2413A are as follows: 1. High-performance 16-bit CPU core
a) Sunplus 16-bit u'nSP processor (ISA 1.2)
b) On-chip phase-locked loop-based clock generation module
c) Maximum system frequency Fck: 24MHz
2. On-chip memory
a) 32K Words (32K×16bit) Flash
b) 2K Words (2K×16bit) SRAM
3. Operating temperature: -40℃～85℃
4. 10-bit ADC module
a) Programmable conversion rate, maximum conversion rate 100Ksps
b) 8 external input channels
c) Can be linked with timers such as PDC or MCP to realize electrical parameter measurement in motor
control
5. Serial communication interface
a) Universal asynchronous serial communication interface (UART)
b) Standard peripheral interface (SPI)
6. 64 (QFP80)/48 (QFP64) general-purpose input and output pins
7. Programmable watchdog timer
8. Embedded online emulation circuit ICE interface: can realize online
emulation , debugging and downloading General 16-bit timer/counter 1. PDC timer
a) Two PDC timers: PDC0 and PDC1
b) Can process three capture inputs at the same time
c) Can generate three PWM outputs (center symmetric or edge mode)
d) Dedicated position detection interface for BLDC drive
e) Two-phase incremental encoder interface, supports four working modes, and
has a quadruple frequency circuit
2. MCP timer
a) Two MCP timers: MCP3 and MCP4
b) Can generate three-phase six-channel programmable PWM waveforms, such as
three-phase SPWM, SVPWM, etc.
c) Provide PWM duty cycle value synchronization loading logic
d) Can be selected to be synchronized with the position detection change of PDC
e) Programmable hardware dead zone insertion function, the dead zone time can
be set
f) Programmable error and overload protection logic
3. TPM timer
a) One TPM timer: TPM2
b) Can process two capture inputs at the same time
c) Can generate two PWM outputs (center symmetry or edge mode)
Two CMT timers 3 System overall plan introduction
This high-performance three-phase variable frequency power supply system is mainly composed of Lingyang 16-bit single-chip microcomputer SPMC75F2413A and Sanling's IPM power module chip PS21865A. The system block diagram is shown in Figure 3-1.
Functions of this system:
The system operation parameters can be adjusted to adapt to the needs of different applications to adjust the system's output frequency and output voltage;
It has real-time information and status display, which is mainly used for the current system status information display and part of the human-machine interface;
It has a keyboard for system parameter setting and control;
Complete system protection function to protect the system from damage when the system is abnormal;
System workflow:
SPMC75F2413A receives the control information from the keyboard or communication interface according to the settings and generates the corresponding SPWM drive signal. The signal is output after power conversion, output filtering and output transformer of PS21865A. At the same time, SPMC75F2413A will monitor the operation of the system at any time to ensure normal output. Once an abnormality occurs, it will immediately protect and alarm to remind the user to handle it. 4 System Hardware Design
The core circuit of the whole system is the waveform synthesis circuit, and its structure and performance determine the performance of the whole system. The waveform synthesis circuit of this system is composed of SPMC75F2413A, power module PS21865A, output transformer and output filter circuit. PS21865A has a three-phase power bridge and corresponding drive circuit inside, which is used to realize the power amplification function of SVPWM signal; the output transformer and output filter circuit are mainly used to convert the output power SVPWM signal of PS21865A into sinusoidal output and filter out its high-order harmonics to ensure the purity of the output waveform; and the main functions of SPMC75F2413A microcontroller are: 1. Generate the SVPWM signal required to drive the variable frequency power supply. 2. Complete human-computer interaction to facilitate user control of the system. 3. Process related abnormal information to ensure the safety and reliability of the system. The three-phase complementary SVPWM signal generated by SPMC75F2413A is output through IOB0~5 of the chip to control the three-phase full-bridge circuit of PS21865A. The signal is output to the load after power synthesis, low-pass filtering and three-phase output transformer. At the same time, the system's operating current and output voltage will be fed back to SPMC75F2413A for system control. IOB6 and IOB7 of SPMC75F2413A are error detection and overload protection input terminals. By detecting the signals sent back, once PS21865A has an abnormal operation (such as overvoltage, undervoltage, overcurrent, overheating) and the system is overloaded, the driver hardware will immediately prohibit PS21865A from working, and apply for interruption and request CPU processing.