The difference between digital and analog loops
Analog controlled power supply ----- s domain (continuous)
Digitally controlled power supply - z domain (discrete)
Digitally Controlled Power Supply Design Method (Direct/Indirect)
Six, the use of related instruments and software
Loop Analyzer - The Most Powerful Assistant for Loop Design
Mathcad
Introduction: Mathcad is an interactive numerical calculation system. When you input a mathematical formula, equations, matrix, etc., the computer will directly give the calculation result, without having to consider the intermediate calculation process, just as simple as drafting. "WYSIWYG" computing tools. Therefore, MathCad undertakes complex mathematical calculations, graphic display and document processing in many fields of science and technology. It is an invaluable tool for engineers and technicians.
Mathcad has five extension libraries, namely solving and optimization, data analysis, signal processing, image processing, and wavelet analysis.
Main operational functions: algebraic operations, linear algebra, calculus, symbolic calculations, 2D and 3D charts, animations, functions, programming, logical operations, definition and calculation of variables and units.
Personal evaluation: Mathcad integrates programming, calculation, display, and documentation in one. It is very suitable for power development and calculation applications (such as design calculation books, etc.), which can significantly improve the development efficiency and strongly recommend everyone to use!
The previous loop design example is done using Mathcad. The entire loop design process is a mathematical calculation. Handle complex math operations to Mathcad to solve it!
Simulation software - saber
Introduction: Known as the world's most advanced system simulation software, and the only multi-technology, multi-domain system simulation product, it has become the industry standard for mixed-signal, mixed-technology design and verification tools for electronics, power electronics, and electromechanical The integration of mechanical, optoelectronics, optics, control, and other types of system-based hybrid system simulation is the biggest feature of SABER. As a hybrid simulation system, SABER can be compatible with mixed simulation of analog, digital, and control variables, which is convenient for analyzing and solving problems at different levels. Other simulation softwares do not have such functions. The reality of SABER is very good, from the simulation circuit to the actual circuit implementation, the basic parameters do not need to be modified.
The main function:
(1) Schematic input and simulation
(2) Data visualization and analysis
(3) Model Library
(4) Modeling
Disadvantages: The operation is more complex and the schematic simulation often does not converge causing the simulation to fail. Contributing to system resources, loop sweeps take too long (in tens of minutes)
Personal rating: Very good, but very depressing. But anyway, No 1 in power simulation software
Simulation Software - psim
Introduction: psim is a specialized simulation tool for power electronics and motor control applications. Psim has the advantages of fast simulation functions and a friendly user interface.
Main advantages: The most important difference between psim and other simulation software is its fast simulation speed. The loop sweep speed is fast (a few minutes of complex points), and schematic simulation can basically converge. The designer can design directly based on the simulation knowledge such as master circuit and control method.
Disadvantages: Waveform and data analysis capabilities are weak, not precise and detailed.
Personal evaluation: convergence is good, suitable for the principle of simulation, speed. Basic enough.
Simulation software - simplis
Introduction: 10 to 50 times faster than SPICE SIMPLIS can be used as a circuit simulation software to optimize the switching power supply system. Like SPICE, component level analysis is possible, but its switching circuit
The transient analysis is 10 to 50 times faster than SPICE.
Unique Analysis Mode For transient analysis, SIMPLIS has more than two analysis models for SPICE products. One of these is the PeriodOpera-ting Point or POP analysis.
This analysis method can quickly determine the steady state operating point of the switching system without the need for circuit startup transient simulation. An application example of this analysis mode is the study of the transient effects of load on the switching power supply system. This is only meaningful if the system is initialized to a steady state. Generally, the circuit needs several thousands of switching cycles to reach steady state. The POP analysis requires only a few cycles to determine the balance of the circuit, which greatly reduces the overall simulation time. The second unique analysis mode is small signal AC analysis. Although traditional analog simulators such as SPICE also have this analysis mode, their static analysis methods are not suitable for switching circuits. The AC analysis of SIMPLIS simulates the sweep measurements of real hardware circuits and obtains the amplitude-frequency curve without the need to obtain an average model.
Personal evaluation: simulation speed. However, the loop sweep setting is more complicated.
The waveform analysis ability is too weak. You can find out if you are interested.
Simulation software-matlab
Seven, experience sharing
Oil machine power
Circuit characteristics: This power supply is a basic buck topology. It uses current inner loop and voltage outer loop control mode.
Coping strategies: For the double-ring nested control method, the inner ring should be designed first. The outer ring can only be designed if the inner ring is designed well.
Since the transfer function of the small-signal model of the power stage current of the buck topology main circuit is known to us very clearly, we can use Mathcad or matlab to design the loop according to the previous method. (actually mathematics)
Experience sharing: For the main circuit power level small signal model (eg buck, boost, flybcak,
Half-bridge, full-bridge) With the explicit transfer function, you can use Mathcad or matlab to design the loop.
Power supply
Circuit characteristics: The power supply is a three-level topology, using current inner loop, voltage outer loop control method
Coping strategies: For the double-ring nested control method, the inner ring should be designed first. The outer ring can only be designed if the inner ring is designed well.
Since the transfer function of the small-signal model of the power level current of the three-level topology main circuit is not well understood, the transfer function of the power stage can be first obtained by the frequency sweep method using simulation software (saber, psim, etc.), and then the loop can be designed.
Experience sharing: For the case where the transfer function of the main circuit power stage small-signal model (for example, LLC) is not clear, the simulation software can be used to design the loop.
Eight, summary
The purpose of this article: Let beginners master the basic concepts and processes of loop design, instill the concept of design, because the quality of the product is designed. Since this article is a preliminary article, only the design ideas and methods are discussed. The detailed loop design rules are not included in this article. Please refer to other books or later training exchanges.
The loop is a relatively complex and tedious problem. The design is only for beginners to find a way to get a good loop without too much experience, avoiding blind attempts and patchwork in the early days. Of course, because this design is based on theory, it must be verified, debugged, and modified in the actual application environment circuit until it meets the requirements of the circuit indicators and avoids talking on paper.
Experienced developers usually only need to use experience and oscilloscopes to debug a good loop, and look forward to these colleagues can share the loop debugging experience, thank you!
2.00MM VDSL Cable Connector.SCSI Connector Series.
2.00MM VDSL Cable Connector
ShenZhen Antenk Electronics Co,Ltd , https://www.pcbsocket.com