One day, the northwest urban area experienced power outages three times, lasting half an hour each time.
Master Yan Yan Zhuoshou said that after looking at the measured current, there were several places where the waveforms were similar.
Yonghan asked, "Is this power outage related to these currents?"
"There are large currents in these places with similar waveforms. The waveforms of each electrical appliance are unique. Some are capacitive loads and some are inductive loads."
Considering the production cost, current detection devices and power quality detection devices are not installed everywhere. Several key points were installed, and similar high current waveforms were detected.
"The sampling frequency of these sensors is extremely high, so they cannot be the same by coincidence. They should be the same type of electrical appliances."
There are mainly garbage stations, Beili equipment factories and construction sites in the northwest urban area. At this time, Meng Jianqi also called Yonghan to ask if he had any clues about the power outage. Yonghan said he didn't know what the situation was. Meng Jianqi drove over and asked Shang Yonghan, Yan Zhuoshou and Fu Shuo to go and have a look.
Arrived at the garbage collection station. I met the worker Tian Suzhen. He said that there are large machines here, namely excavators and cranes, and there are several purifiers that are not in use recently. Landian originally had a purifier, but it couldn't purify it for a long time. After it was scrapped, it was sent to the garbage recycling station and stuffed into the metal garbage pile.
Meng Jianqi said: "Can we look at the usage records of excavators and cranes?"
Tian Suzhen said, "Okay, check the fuel level, battery power, etc."
Several people went to check the oil level of the excavator, but there was no record of any decrease.
“What type of excavator is this exactly?”
"The front shovel excavator's shoveling action is characterized by "forwarding upward, forcing the soil to be cut." The front shovel has a strong digging force and can excavate soil above the stopping surface. It is suitable for excavation of dry foundation pits with a height greater than 2m. However, up and down ramps must be set up. The bucket of a front shovel is larger than that of a back shovel of the same size. It can be used in conjunction with a dump truck to complete the entire excavation and transportation operation. It can also excavate large dry foundation pits and mounds. There are two methods for digging and unloading soil with a front shovel excavator: forward digging and side unloading; forward digging and reverse unloading."
They looked at the excavator's bucket, tracks, and hydraulics, which had been in use for the past few days, but didn't see anything special.
Arriving at Beili Equipment Factory, this is a factory that makes electromechanical CNC equipment for other factories. Hou Jinkun, the person in charge of the factory, came out and said, these are the large processing equipment. Recently the pollutants have exceeded the standard. CNC system is an automatic control system using digital control technology. CNC machine tools are a type of machine tools that use digital control technology to automatically control the machining process of the machine tool. A CNC machine tool is an efficient automated machine tool equipped with a program control system and is an example of a typical application of CNC technology. It uses coded digital quantities to control machine tools, automatically controls the movement of each part of the machine tool according to pre-programmed programs, and can also control tool selection, tool change, measurement, lubrication, cooling and other tasks.
"I learned about self-assembly chips last time and designed a new type of machine tool with the help of this chip. This kind of machine tool has an intelligent fault self-repair function and can determine the cause and location of the fault based on diagnosis to automatically troubleshoot or guide the troubleshooting. Intelligent Self-healing technology integrates fault self-diagnosis, fault elimination, self-recovery, and self-adjustment, and runs throughout the entire life cycle of the processing process.”
"Okay. Thanks for the introduction. I don't think these devices will cause power outages."
When we arrived at the construction site, foreman Han Leiguan came out and said that excavators, tower cranes, bulldozers, etc. were used on the construction site. Some machines now use high-energy batteries. The energy density of the battery cells is 600Wh per kg.
The negative electrode of a sodium-sulfur battery is molten metallic sodium; the positive active material is molten sodium polysulfide, usually filled in porous carbon, which serves as the positive electrode current collector. Conductive ceramic tubes need to be used to separate sodium from sodium polysulfide to prevent self-discharge caused by direct reaction. In addition, the ceramic tube also serves as the electrolyte in the battery. It enters the positive electrode through a conductive ceramic tube and reacts with sulfur to form polysulfides. The discharge ends when the sodium in the negative electrode is exhausted. In order to keep both sodium and sodium polysulfide in a liquid state, the discharge needs to be carried out at around 300°C. The upgraded sodium-sulfur battery is more suitable for use as a vehicle power battery.
Meng Jianqi said: "Can we look at the usage records of high-energy batteries?"
"OK, no problem."
Several people went to check the excavator battery, but there was no record of degradation.
Several people thought about what kind of electrical equipment caused the power outage at the garbage station, Beili Equipment Factory, and construction sites.
Everyone went to the recycling station again and arrived at the steel waste processing area. They saw signs that the steel waste had been moved nearby. It might have been that the excavator had lifted it, taken out some items, and then put the items on top back.
Fu Shuo said, "I don't understand. Didn't the camera capture it?"
Meng Jianqi said, "During the power outage, the camera was out of power."
Fu Shuo said, "It happened to be a power outage and the excavator was driven away?"
Meng Jianqi said, "There were three power outages, each lasting half an hour..."
Yonghan said, "The excavator can't run that fast, can it?"
Meng Jianqi said, "Yes, it takes 20 minutes to drive an ordinary car from the construction site to the recycling station."
Yonghan said, "Maybe it's not an excavator."
Meng Jianqi said, "That is?"
Yonghan said, "Where's the tower crane or the crane?"
Meng Jianqi thought about it and said, "There were two power outages, one from the construction site to the recycling bin, and one from the recycling bin to the construction site. Let's go to the construction site to have a look."
Everyone came to the construction site again. There is a back door where sometimes some construction machinery tools come out. There's a camera on it.
Fu Shuo said, "During the power outage, there was also a power outage here, so the camera didn't capture anything."
Meng Jianqi asked, "Are there any traces of use on the high-density batteries of the construction machinery here?"
"There is no record of use. If used, there will be records of reduced power."
"Could it be that it was recharged after use?"
"No, charging and usage are recorded."
Yonghan said, "What if other batteries are used?"
Meng Jianqi asked, "Do you bring your own battery?"
Yonghan said, "When there is a power outage, it can be deduced that someone used a high-current electrical appliance; what are the tools used? It may be a high-density battery. This high-current electrical appliance may be a high-density battery! The traces of steel movement can be deduced to be left behind by construction machinery. The ones that rained down were construction machinery that had been in the area, and the power outage gave them time to do these things.”
Meng Jianqi said, "Yes, high-density batteries cause power outages. Power outages cause cameras to not work. At the same time, high-density batteries are used to start construction machinery."
Fu Shuo said, "Then what kind of metal equipment did they transport? Is it related to the Beili Factory?"
"Their pollutants have recently exceeded the standard. A discarded heavy metal processor from Landedo Company was thrown here."
"So that's it. They want to take this away and temporarily deal with the heavy metal pollutants, but they can only temporarily deal with it so that the emissions can meet the standards."
