Energy-saving society

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Now we have entered a conservation-oriented society. How to improve the efficiency of power supply and create energy-saving design is a topic facing power engineers.
Viewpoint 1: Improving power efficiency is part of power management.
Improving power efficiency is a special technology, mostly composed of hardware circuits, such as efficient switching power supply (DC-DC conversion), but it is only a part of power management, not all. At present, in order to make it easier for designers to manage power, some manufacturers have also developed power management software for embedded operating systems. Using such operating systems can effectively reduce the workload in software compilation and optimize the power management of the system. Therefore, power management includes both power conversion efficiency and load power reduction.
Viewpoint 2: Power energy saving requires synchronous rectification IC. More than
20 years ago, the power supply was changed from linear to switching design to achieve the purpose of saving energy. Today, in order to further improve the efficiency of power supply, more and more complex designs have been derived from the switching power supply design, with the aim of meeting more stringent energy-saving requirements. For example, the standard PWM IC UC384X series, which was widely used in the early days, now has the PWM IC SG6841 with the same function. It not only boasts ultra-low startup current and low standby current, but also can minimize the standby power consumption of the entire system. In addition to achieving the purpose of energy saving, it also demands advanced functions. In addition to the evolution of ICs, the efficiency of line architecture is also improving. For example, in terms of loop design, the design method of the secondary side of SMPS has evolved from general asynchronous rectification to the current synchronous rectification. In order to adapt to the trend of energy saving, the design trend of power supply devices has also evolved. Power supplies have shifted their attention to the competition on the secondary side of AC-DC, entering a major reform to improve energy efficiency, and pushing the efficiency conversion rate of AC-DC to a high point.
Viewpoint 3: Three problems to overcome in order to improve the efficiency of portable power
For power system design engineers, improving the efficiency of portable power requires facing new challenges. They must overcome the following technical problems:
① Integration technology: The first problem to be solved is how to power each built-in circuit that performs different functions. The crux of the problem is that most of these circuits operate at different voltages.
②Energy efficiency: These portable electronic products are all battery operated. Whether the battery life can be extended or not, the design of the power management system plays a decisive role.
③In addition, engineers have to maximize the power conversion efficiency on the one hand, and on the other hand, they have to ensure that the product is light and thin, easy to carry, and dissipates very little heat. It is not easy to strike a proper balance among so many requirements. To solve the above problems, a well-considered all-round solution is needed.
Viewpoint 4: The concept of power quality control and power saving has become popular
. At present, a new power saving concept-"power quality control and power saving" has become popular. It combines high-quality power consumption with high-efficiency power consumption, and improves the operating efficiency of the equipment by removing power pollution and improving power quality, thereby achieving the purpose of power saving. It can effectively suppress transient surges in the power grid circuit, filter out high-frequency harmonics, improve the operating efficiency of the equipment, and extend the service life of the equipment through multi-stage transient suppression components, multiple tracking filters and unique internal design. It has the dual functions of saving power and protecting equipment. Its power saving protection principle is mainly manifested in the following four aspects: ① filtering out high-order harmonics to save power, ② suppressing transients to clean and save power, ③ metering to save power, and ④ cooling and saving power.
Viewpoint 5: Several issues to improve battery efficiency
Two keys to
battery life The two keys to improving battery life are nothing more than improving the efficiency of power supply and reducing the power consumption of loads. Improving the efficiency of power supply means choosing a suitable voltage conversion circuit. Reducing system power consumption mainly depends on two indicators, namely working current and static current. For working current, generally, chips or components with lower power consumption are used in design, and the load of the circuit board is minimized during wiring. Many power chips can be controlled by microprocessors, and different current outputs are selected according to current consumption. For static current, chips with lower static current are generally selected, all unused chips are put into sleep mode, and all unused IO ports of the microprocessor are turned off, such as automatically turning off the display backlight when there is sufficient light, or putting the audio chip in sleep standby mode when the headphones are not plugged in, etc.
Improve power conversion efficiency
In the power management system of new battery-powered products with rich functions, it is often necessary to perform multiple step-up and step-down conversions on the input voltage to meet the needs of various functional blocks. For mobile phones, the display backlight, processor, memory, flash, etc. require different power supply voltage inputs. How to reduce the waste in the input-output conversion process, that is, to further improve the conversion efficiency, is the most important focus of portable device power management. Another increasingly prominent development trend is to use switching power supplies to replace linear regulators, because this can greatly improve the conversion efficiency and thus extend the battery life.
Reduce load power consumption
In the case that the power density of existing batteries cannot be significantly improved, reducing the load power consumption of various functions of portable products is an important guarantee for increasing battery life. For example, in a fully functional mobile phone, the various functions are ranked by power consumption, in order of speaker, color display, flash, camera, call, MP3, etc. Among them, the first three are the largest energy consumers, consuming more than 300 milliwatts of power, and the output power of the speaker with hands-free function is even as high as 2 watts. Therefore, how to further technically transform and upgrade the power management of these high-power consumption functions has become one of the important directions for extending the battery life of portable systems.
Viewpoint 6: Three laptop CPU power saving technologies are worth paying attention to
Intel SpeedStep technology
Speed Step is a technology used by Intel CPU. In the mobile Pentium processor after the mobile Pentium-3600MHz, Intel added a technology to reduce power consumption by reducing the CPU operating frequency - SpeedStep. (In the mobile Pentium M processor, Intel redesigned this technology and called it "Enhanced SpeedStep") It allows the processor to switch between two working modes at will, namely the maximum performance mode (Maximum Performance Mode) in AC state and the battery optimized mode (Battery Optimized Mode) in battery state. The so-called maximum performance mode means that when the laptop is connected to AC power, it can provide performance similar to that of a desktop computer; while the battery optimized mode means that when the laptop is using battery, it will achieve the best balance between the performance of the laptop and its battery life. For example, 650MHz and 600MHz processors using SpeedStep technology can provide operating frequencies of 650MHz and 600MHz respectively when they run in the highest performance mode, and the operating frequency of the processor is 500MHz when they run in the battery optimization mode.
Mobile PentiumⅢ or Pentium4 chips use SpeedStep technology that automatically adjusts dynamic frequency and voltage switches, which allows them to switch between higher operating frequencies and battery energy optimization. The BIOS of the notebook system knows that the CPU has the SpeedStep function through the CPU registration ID tag. After determining whether the notebook is powered by AC power, the BIOS and ASIC will issue instructions to the CPU and make it run in the corresponding mode. All of this will be completed within 500μm.
In fact, for users, if it is not a new chart loaded on the system platform, SpeedStep technology is almost invisible. But in the background, SpeedStep technology does take on the responsibility of finding a balance between higher operating speed and longer battery life. In order to enable users to understand the current working status, Intel has set up a flag-shaped icon in the system platform to indicate the operation mode. Unless otherwise specified, the SpeedStep system defaults to a non-power-saving working mode unless it is powered by a battery. If you want to customize the settings, users can achieve this function from the power management project in the Windows Control Panel.
Today, SpeedStep technology has developed to the second generation, called Enhanced Intel SpeedStep technology. The new technology has added automatic mode, super performance mode, battery optimization performance mode, etc.
AMD PowerNow! Technology
This power management technology will increase or decrease the voltage and main frequency of the processor according to the needs of different applications, so that the processor can better meet the needs of actual applications, thereby extending the battery life of the laptop and extending the battery life.
AMD PowerNow! technology provides three working modes: automatic mode (the system monitors applications and makes adjustments when necessary), high-performance mode (the processor runs at the highest frequency and voltage), and power saving mode (the processor runs at the lowest frequency and voltage to extend the battery life). However, the number of working modes will depend on the design of different notebook computer manufacturers.
LongRun technology
LongRun technology is a power management technology developed by Transmeta. The characteristics of this technology are low power consumption and just enough voltage for the processor. The principle is to use the program to monitor whether the CPU is idle. If it is idle, the voltage and frequency will be reduced to meet different needs.
Viewpoint 7: There is a limit to the power saving design of the power supply.
Single power saving research and development can be completed in one fell swoop, but it is quite difficult to achieve comprehensive power saving. First, it requires the developer to have considerable patience and observation to see the entire energy space; second, it requires sophisticated analog circuit technology and knowledge, because most energy saving problems involve analog circuit knowledge; third, it requires creativity. The appropriate system structure and circuit details can achieve better cost-effectiveness and power saving effects at the same time. Power-saving technology seems to have an upper limit. When all static power consumption and wasted dynamic power consumption are saved, the savings reach a limit.