Good news!Maxge Electric receives numerous government awards, making a good beginning in 2019! 

by MAXGE

Facing of the complex and ever-changing domestic and international environment in year 2018, we MAXGE Electric fully understands the strategic significance of China’s “One Belt, One Road”, promoting common development, achieving common prosperity, getting win-win cooperation, enhancing understanding of trust, and strengthen all-round communication. With the leadership and policy support of our local government Huzhou, we have achieved remarkable results in many aspects such as business growth, brand enhancement, product and trade expansion!

Year 2018 MAXGE ELECTRIC CO. Was rated as:

  1. Zhejiang province Contract-honoring company
  2. Zhejiang province innovative demonstration SME
  3. Zhejiang province clean production enterprise
  4. Zhejiang province export brand
  5. Huzhou city informatization and industrialization fusion demonstration enterprise
  6. Huzhou city green factory
  7. Development economic contribution award
  8. Economic development award
  9. informatization and industrialization fusion management innovation award
  10. Technical gazelle enterprise
  11. Enterprise bigger and stronger award
  12. Marketing development award

In year 2018 we MAXGE also participated in the formulation of relevant national and industry standards such as:
GB/Z 36281-2018 Residual current protection device combined with additional functions. Published in 2018-06-07 and implemented in 2019-01-01.
NB/T 42149-2018 Miniature circuit breaker with remote control RC-MCB.
Published in 2018-04-03 and implemented in 2018-07-01.
NB/T 42150-2018 Low voltage surge protector special protection equipment.
Published in 2018-04-03 and implemented in 2018-07-01.

In year 2018, MAXGE Electric was recognized by the government and the community, and its efforts were inseparable.First of all, MAXGE invested a lot of money in product development and technological innovation, A 30,000 square meter modern industrial plant infrastructure is ready. Purchased some equipment and instruments  of CNAS standard laboratories.this year also more than a dozen new product patent declarations have been completed, and many products have obtained the certificate of VDE, the top international certification body.

MAXGE Electric will participate in the “MEE2019”

by MAXGE

The 44th Middle East Electricity, Lighting and New Energy Exhibition (Middle East Electricity or MEE) will open at the Dubai International Exhibition Center on March 5.

MEE is hosted by the energy and industry department of the united Arab emirates (uae). It is the most influential power and new energy professional event in the world. It is honored as one of the world’s top five industrial events. With more than 70,000 square meters of exhibition area, thousands of excellent power and lighting enterprises in the world participated in the exhibition and attracted more than 50,000 visitors from 114 countries and regions.

At this exhibition, MAXGE Electric will display the latest products independently developed for the needs of the Middle East market, such as MCB, MCCB, AFDD and smart home solutions. Our booth number is H6.B20.

MCB

 a. Sophisticated inner core and logical magnetic coil for quick protection.
 b. Two connection modes: By Cables and Busbars for more firmness.
 c. Ventilating design for quicker cooling and stability.
 d. Stickers available under transparent protective cover for rooms recognition.
 e.Thermosetting and anti-flaming shell for carbonization when fired
 f. Automatic close with less electric spark for extended working life of appliances.
 g. Protection degree: IP20—To guarantee a safe and reliable connection.
 h. Stain-resistance:  Level Ⅲ—To prevent dust and conductive pollution.

MCCB

 a. 4 optional breaking capacities; A variety of frame currents
 b. Modular assembly and complete accessories.
 c. Flexible Mounting & Connection: Plug-in, Rear Connection
 d. Good conductivity
 e. Thermosetting and flame retardant shell for carbonization when fired
 f. Two optional poles: 3P and 4P for more applications.
 g. Optional ground fault protection
 h. More settings for more accurate protection

AFDD

a. Control electric circuits.
b. Protect people against indirect contacts and additional 
c. protection against direct contac
d. Protect installations against fire hazard due to insulation faults.
e. Residual current circuit breakers are used in housing, tertiary
f. sector and industry.

 a. It performs good and stable on electrical conductivity with silver alloy contacts.
 b. Its copper coil is not easy to turn hot and burn out
 c. High quality flame-retardant shell ensures stable performance and safety
 d.32 pieces of high quality silicon steel core for smoother suction and stronger loading capacity

A Zero Distance Between MAXGE ELECTRIC and AI

by MAXGE

“There will be only two kinds of enterprises in the future, artificial intelligent  and unprofitable.”——TCS 《2017 Annual Report of Global Trend》

Today, as an ordinary worker, how far is it from artificial intelligence?

Last night, Mr.Zhang saw an American movie called “Western World” when he  could only touch the artificial intelligence by artistic imagination.

.In the morning, Mr.Zhang browsed news on the way to work and saw a variety of information about AlphaGo. Now the distance between him and the artificial intelligence is just as the one between news and life.

As a warehouse keeper working for 10 years in MAXGE ELECTRIC, he found that everything in the warehouse was placed in an updated position. In the evening, he also found it very smooth and easy to move goods today, the workload of which was equal to that of the past half-day. At this time, artificial intelligence has affected his work and become his vital colleague and partner that he can’t even see or touch.

Cases above are not far away, and it is just happening today. In the field of AI for enterprise service, there are cases that it has helped enterprises achieve the warehousing system optimization by a deep calculation. Results shows that after the optimization, the warehouse keeper walks from 30,000 steps reduced to 20,000 steps and working efficiency is improved by 30%.

Artificial intelligence also has happened to Mr. Zhang’s wife, Mrs. Wu, who is engaged in production management for 10 years in MAXGE Electric. She is responsible for orders management every day. Tracking the orders becomes her top priority, taking up two-thirds of her working time.However, today when coming to the office, she found a new AI smart module, ERP system, through which she just needs to knock the keyboard at the seat for production  management, as well as her assistant, who just stops calling and urging the human resources for recruit.

This may indicates that the distance between artificial intelligence and people is infinitely close to zero.

The annual report global trends from a world-renowned consulting firm,TCS, reveals that 84% of the enterprises surveyed around the world regard artificial intelligence as a key element of competitiveness.

From the amazement at AI to the utilization of AI, what else do we need to do?

1、Production Efficiency Optimization

Artificial intelligence entering the enterprise is to optimize the data structure by  understanding the enterprise data, and work out the reasonable manufacturing model by intelligent calculating. Therefore, the efficiency of intelligent artificial  is more greatly improved than that of manual judgement.

For example, in the case of sample testing, in the past, MAXGE Electric was always mainly relied on manual inspection and experience judgment,which led to higher mistake and lower efficiency due to the manual technical ability and lack of the talent. However, in the era of intelligence, MAXGE Electric accurately judges the equipment and products through image recognition and automatic correction system, which has greatly improved its efficiency.

Costs Reduction

By the artificial intelligence technology, the enterprise can not only improve the product qualification rate, reduce labor costs, but also can increase the production safety. What’s more, It is also available to improve the quality of manual by the tool of artificial intelligence and reduce the costs on many aspects of the enterprise.

For example, for the Finance department of MAXGE, filling all kinds of invoices is quite essential. However, traditional manual filing is very labor intensive and easy to make mistakes. MAXGE,with the intelligent OCR system, can quickly convert the invoice document into an electronic version, which has saved a lot of labor time and cost for efficiency improvement.

In addition, artificial intelligence can also contribute to reducing social costs and improving social efficiency and ecological environment. In the process of product testing, the constant temperature of the testing room is an important factor for inspection. Through the artificial intelligence technology, it can precisely adjust the heating of the testing room according to the indoor and outdoor temperature, and finally achieve that the power consumption could be reduced by 10% under the condition of 30℃ in the room. It is a big advancement of temperature adjustment compared to the traditional manual operation.

From “Concept” to “Application”: MAXGE has an access to it.

It should be noted that in the process of artificial intelligence moving from concept to reality, it is still not clear how to apply the concept to the industry. Many enterprises have invested a lot of resources to build artificial intelligence, but the results are not so satisfactory.

In such a fast updated trend, when faced with the clear future and difficulties as well, MAXGE is entering the intelligent world by several appropriate ways.

1、 Get a quick access to artificial intelligence through cloud service.

2、looking for mature intelligent solutions.

3、Improve the intelligence by academic advantages.

It will become one of the main themes in the next long time for MAXGE from intelligence concept to practical application.

What is an Residual Current Device(RCD)?

by MAXGE

Residual Current Device (RCD) is a leakage protection device. The leakage protection device is a low-voltage safety protection device, and its functions are as follows:
1. Used to prevent single-phase electric shock accidents caused by electric leakage;
2. It is used to prevent fires and equipment burning accidents caused by electric leakage;
3. Used to detect and cut off various phase-to-phase faults;
4. Some leakage protection devices can also be used for overload, overvoltage, undervoltage and phase loss protection.

Residual Current Device

Its working principle: When electrical equipment leaks, it will show abnormal current and voltage signals. The leakage protection device detects the abnormal current or abnormal voltage signal, and the signal processing causes the actuator to operate. The power supply is quickly cut off by the switch device, and the leakage protection device is operated according to the fault current. The leakage protection device is a current-type leakage protection device, according to the fault voltage. The action is a voltage type leakage protection device.

The following mainly introduces the current type leakage protection device (RCD).
There are three main components in its composition, namely, detection components, intermediate links (including amplification components and comparison components), and actuators. Second, it also has an auxiliary power supply and test equipment.
(1) Detection component. It is a zero sequence current transformer as shown. In the figure, the phase line and the neutral line of the protected main circuit pass through the loop core to form the primary coil N1 of the transformer, and the winding uniformly wound on the loop core constitutes the secondary coil N2 of the transformer. The function of the detecting component is to convert the leakage current signal into a voltage or power signal and output it to the intermediate link.
(2) Intermediate links. Its function is to process the detected leakage signal. The intermediate link usually includes an amplifier, a comparator, a trip unit (or relay), and the like. Different types of leakage protection devices have different types of specific configurations in the intermediate links.
(3) Implementing agency. The mechanism is configured to receive an instruction signal of an intermediate link, perform an action, and automatically cut off the power source at the fault. The actuators are mostly automatic switches or AC contactors with shunt release.
(4) Auxiliary power supply. When the intermediate link is electronic, the auxiliary power supply serves to provide the low voltage power required for the operation of the electronic circuit.
(5) Test device. This is the device used to periodically check the running earth leakage protection device. A branch circuit in series with a check resistor is usually used to simulate the path of the leakage to verify that the device is functioning properly.

Photovoltaic modules quality issues

by MAXGE

In recent years, the photovoltaic industry has developed rapidly, and the number of installations of photovoltaic power plants is also increasing. The quality of photovoltaic modules will directly affect the power generation of photovoltaic power plants, and the failure of photovoltaic modules is also increasing.
As we all know, the entry of solar photovoltaic products into the market is basically through the certification requirements of various countries. Why are there such serious quality problems? There are several reasons:

photovoltaic modules

1. The test standard of photovoltaic modules is not perfect.

At present, the main component testing standards used in the industry are: “IEC61215:2005 Design and Identification of Crystalline Silicon Photovoltaic Modules for Surface Use”, “IEC61730-1:2004 Structural Requirements for Safety Identification of Photovoltaic Modules”, and IEC61730-2:2004 Photovoltaics Experimental Requirements for Component Safety Appraisal and UL1703:2004 Planar Photovoltaic Modules and Flat Panel Standards, and these standards are for single-component components, and the simulated outdoor environment is a single factor or two or three factors in the actual outdoor environment. The azimuth of the analog component is 25 years of outdoor power generation. Have you noticed that none of the test standards mentioned above have a test standard declaration or indicate that all items that have passed this standard prove that the component has a service life of 25 years.

Therefore, the International Electrotechnical Commission is also working on some new standards for the current industry, such as “IEC61701: 2011 Salt Spray Test Standards”, “IEC62804 (draft) Potential Induced Attenuation Effect Test Standards”, “IEC62716:2010 Photovoltaic Modules” Ammonia Corrosion Test Standards. China Quality Certification Center launched “CQC3303-2013 Ground Crystalline Silicon Photovoltaic Module Environmental Adaptability Test – Dry and Hot Weather Conditions” according to China’s different regional climate environment, “CQC3304-2013 Ground Crystalline Silicon Photovoltaic Module Environmental Adaptability Test – Damp Heat Climatic conditions and “CQC3303-2013 ground crystalline silicon photovoltaic modules environmental adaptability test – alpine climate conditions” and other test standards. All of these indicate that the test standards for PV modules are not comprehensive enough to prove the long-term reliability of the components of the components through testing.

2, the certification component is not representative

Third-party testing is expensive, such a high testing cost, which company will casually test out! And which company will randomly pump or send the worst products to third-party testing! This is destined for the company to send products to third-party testing. At the time, you will be very cautious, not only using high-quality materials, high-quality production processes, but also re-selecting in the final product, and finally sending the products that have been screened several times to third-party testing. Of course, the significance of this test is only to obtain a certificate of conformity, then how to guarantee the quality of the company’s products?

3, can not achieve continuous monitoring of product quality

The type inspection, supervision and inspection, supervision and inspection of the third party are very simple, and the inspected party will be notified before the inspection. After receiving the notice, the inspected party will conduct a “concentrated replenishment” in a short period of time; in addition, the photovoltaic industry circle Very small, the inspection agency will also give a “face” during the inspection, so the supervision and inspection by the third party is flawed. Then, everyone will ask, is there no quality control within the company? The answer is yes, every company will “do everything it can” to improve product quality, and this “doing what it can” means making full use of the company’s existing resources. Conduct product quality control. However, in general, there are only a few simple inspection and inspection equipment for production, and there are few equipments that study the structure, performance and service life of photovoltaic modules and materials. All in all, these products are not subject to more comprehensive and continuous quality control.

4, product updates fast, short-lived products become the fish of the net
In recent years, due to the overcapacity of photovoltaics, the entire photovoltaic industry chain has been transformed. Only rapid changes in enterprise products can adapt to changes in the market, and there is a possibility of survival. How to control the quality of products is particularly important in this frequent change. . According to the “61215:2005 Retesting Guidelines”, regardless of changes in the thickness of the silicon wafer, changes in the slurry for the battery, or changes in the backplane and EVA of the components, it is necessary to re-calibrate the corresponding items to ensure product quality. It is impossible to rely on third-party testing for such frequent changes. In addition, the general enterprises themselves do not have systematic testing methods. These inspection vulnerabilities are likely to bring these “revolutionary” unsuccessful photovoltaic products to the market.

5, other reasons
The transportation personnel, installation and use personnel of the components do not understand the products, and do not treat the photovoltaic products according to the standards of the semiconductor industry, resulting in product hidden troubles during transportation and installation. What’s more, some companies conduct malicious bidding for survival, and produce and criticize different products for impersonation. These will lead to uncontrollable quality of photovoltaic products.

Electrical schematic drawing skills

by MAXGE

The electrical schematic diagram is a kind of drawing that we often encounter when we are engaged in electrical work. The simple electrical schematic diagram is easy to understand. For complex electrical schematic diagrams, we must follow certain principles and analysis steps when reading. In order to understand the meaning of the drawings well.

Electrical schematic

First, the basic principles
The whole process is zero, the vines are touched, the first and the second are supplemented, the set is zero, the safety is protected, and the inspection is comprehensive.   The principle of turning to zero is used to target a certain motor or electrical component (such as a contactor or a relay coil) from the power source, from top to bottom, from left to right, and analyze the on-off relationship one by one.

Second, analysis methods and steps
1 Analysis of the main circuit
Regardless of the line design or line analysis, start with the main circuit. The role of the main circuit is to ensure the realization of the machine drag requirements. From the composition of the main circuit, the type and working mode of the motor or the electric appliance, control requirements such as starting, steering, speed regulation, and braking, and protection requirements can be analyzed.
a. Read the device manual and operation manual carefully to understand the operation mode and sequence of the device and the role of the device components in the circuit.
b. The structure of the electrical system is generally understood in comparison with the drawings and drawings, and the contents of the main headings are combined with the contents of the main drawings to have a clear understanding of the types, properties and functions of the circuits.
c. To read the system schematic, you should first read the drawing description. Combine the contents of the description with the drawings, and then understand the general situation of the entire circuit system, form the sequence of components and control methods, and prepare for the detailed circuit schematic.
d. Read the centralized and unfolded circuit diagrams in order to look at the circuit first, then look at the secondary circuit, first exchange the order of DC, from top to bottom, from left to right, step by step, gradually follow the principle, look at each loop, and A comprehensive analysis of the condition of each loop device component and the control of the main circuit to understand the working principle of the entire electrical system.
e. Read and install the wiring diagram to compare the electrical schematic diagram, first circuit, then secondary circuit sequence. Read and install the wiring diagram to understand the meaning of the terminal mark and the circuit symbol in detail with the circuit schematic. For the primary circuit, read it from the power supply terminal, and understand the line connection and the direction until the power device end. The secondary circuit should be read from one end of the power supply to the other end of the power supply. All wires of the same wire number in the wiring diagram can in principle be connected together.

2 Analysis control circuit The main control requirements of the main circuit are realized by the control circuit. Using the principle of “reconstruction to zero” and “successful”, the control circuit is divided into several local control lines according to functions, from the power supply and the main signal. At the beginning, after a logical judgment, the control flow is written to express the automatic working process of the circuit in a simple and clear way.
3 Analysis Auxiliary circuit The auxiliary circuit includes the working status display of the actuator, power supply display, parameter measurement, illumination and fault alarm. This part of the circuit has relative independence and plays an auxiliary role without affecting the main function. Many parts of the auxiliary circuit are controlled by components in the control circuit.
4 Analysis of interlocking and protection link production machinery has high requirements for safety and reliability. In order to achieve these requirements, in addition to reasonable selection of drag and control schemes, a series of electrical protections and necessary Electrical interlocking. In the analysis process of the electrical control schematic diagram, the electrical interlocking and electrical protection links are an important part and cannot be missed.
5 After the overall inspection has been “normalized to zero”, and gradually analyze the working principle of each partial circuit and the control relationship between the various parts, it is necessary to check the entire control line with the method of “collecting zero as a whole” to see if there is any Missing.In particular, we should further examine and understand the relationship between the various control links from the overall perspective to achieve a correct understanding of the role of each electrical component in the schematic.

Wire wiring method

by MAXGE

Wire wiring method, in the process of decoration, hydropower engineering is a very important step, because it is a base project, and it is related to our future electricity safety, so I suggest you understand the relevant knowledge.

Wire wiring
1, conventional winding wiring method

The first common practice is to use two wires to entangle the copper wires. Remember to leave the end and buckle it. This will ensure that the connector of the wire will not be ignited, short-circuited or poorly contacted. I believe this step, many people who are not electricians know.

Note: There should be no joints in the home decoration, especially in the online tube, and there should be no joints. If there is a joint, it should be in the electric box. The usual wire joints are such a connection to ensure that the wire joints do not cause ignition, short circuit, and poor contact.

If you want to use this method, then each wire end must be treated like this in order to effectively avoid the risk of electric shock, and also to see if the master is working professionally. Here you must remind everyone that when you are at home, do not have connectors, especially online management, if there is a connector, it should also be in the wire box.

2, fireproof tape method

This method is used less often, and is generally used in spotlights in ceilings. It should be noted that the main line cannot be broken, and the secondary wire is wound around the main line for 6-8 turns. After that, it is wrapped with fireproof tape outside, which can effectively prevent the wire from burning and burn the outer edge of the outer edge to prevent short circuit at the wiring.

If the wire joint is not wrapped with insulating tape, the wire will be exposed, which will easily cause electric leakage and even electric shock. Therefore, it must be wrapped with insulating tape to prevent leakage.

3, crimping cap connection method

Pressure line is a small tool specially used for wire connection, which is very practical and safe. The most standard and simple to use this method, the matching crimping cap and pliers are required for wiring. It is very important to select the matching crimping cap according to the square of the connected wires. When wiring, press the crimping tool with a crimping wire to press the wire, and put the special pliers for the piezoelectric wire on the pressure wire, and press it firmly. Here to tell you a little, generally use a set of wires do not use insulating tape.

Household power cord introduction

by MAXGE

Wires, wires that carry electricity, are made of copper or aluminum. Due to the different uses, there are various specifications, such as single or multiple strands, bare or covered with an insulator. Household electric wires are generally buried in the wall or underground during renovation, and the specifications are in accordance with national standards. So, what is the home power cord? What are the model specifications for household power cords?

Household power

Household power cord category:
BV, BVR, RV: are single core wires.
BV: It is a single core wire of copper wire, which is relatively hard, also called hard wire.
BVR: It is a single-core wire twisted together with many strands of copper wire, also called a cord.
RV: It is also a soft wire. It is a single-core wire with more strands of copper wire twisted together.
BVVB: It is a hard sheathed wire, that is, two or three BV wires are sheathed together.
RVV: It is a soft sheathed cable, that is, two three or four RV wires are sheathed together.

Generally, household electric wires are simply selected BV or BRV. If it is the storefront decoration, it is recommended to use BVVB sheathed wire.

When purchasing a household wire, you must purchase the wire that meets the national standard. The first thing to look at is whether there is a quality system certificate and whether the certificate is standardized. Also look at its production date and inspection chapter, whether there should be trademarks, specifications, voltages, etc. Then take a wire head and bend it repeatedly, where the hand feels soft, the elasticity is large and the insulator is not cracked horizontally. Generally, the quality of the wire is within a certain range. The plastic insulated single-strand copper core wire with a cross-sectional area of ​​1.5 mm2 is 1.8 to 1.9 kg per 100 m. The 2.5 mm2 plastic insulated single-strand copper core wire has a weight of 3 to 3.1 kg per 100 m. Finally, look at whether the copper core color is purple, shiny, and soft. Inferior general toughness is poor.

Household power cord model specifications

Household power

The selection of household wire specifications should be based on the total power of the household appliances, and then select the appropriate wire and cable according to the maximum current carrying capacity of the wires of different specifications.

Cross-sectional area of ​​commonly used wires: 1, 1.5, 2.5, 4, 6, 10, 16, 25, 35, 50, 70, 95, 120, 150, 185, 240 mm2; cross-sectional area of ​​unused wires: 0.5, 0.75, 300 , 400, 500mm2.

Home improvement wire notes:

The power cords that can be used in households are generally BVVL×2.5 and BVVL×1.5 models. BVVL is a national standard code, meaning a single plastic copper wire, 2.5 and 1.5 represent 2.5 square millimeter wire core and 1.5 square millimeter wire core respectively. Under normal circumstances, type 2.5 is the main line, trunk line and electrical outlet line, type 1.5 lighting branch line and switch line. In the main line of line decoration (refrigerator, air conditioner, TV, washing machine, high-power appliances),

it is reasonable to select a copper core wire with a 2.5 mm square section. It is reasonable to buy a single copper core wire with a cross section of 1.5 square millimeters for the wires of the lighting. Before decorating the cable, you must first determine the location of the fixed wall socket. It is more reasonable to use two or three eye socket panels. Note that during construction, the power cord can not be sheathed with a sheathed wire. Only a single plastic copper wire can be used!

Electrical control system protection measures

by MAXGE

The current era is an information age, information technology is constantly developing, and electrical control systems are becoming more intelligent.

What are the common protection measures in electrical control systems?

First, short circuit protection
Insulation of the motor windings, insulation damage of the wires or failure of the line causes short-circuiting, short-circuit currents and insulation damage to electrical equipment and strong electrical power to damage electrical equipment. Therefore, when a short circuit occurs, the power must be cut off quickly. Commonly used short circuit protection components are fuses and automatic switches.

fuse
1, fuse protection
The fuse of the fuse is connected in series in the protected circuit. When the circuit is short-circuited or severely overloaded, it automatically cuts off the circuit to achieve protection. Fuses are generally suitable for systems that require less accuracy and automation, such as small-capacity cage motors and general AC power supplies.
2, circuit breaker protection

circuit breaker
The circuit breaker, which has short-circuit, overload and under-voltage protection, can automatically cut off the power automatically when the above-mentioned fault occurs in the line. It is one of the important protection components of low-voltage power distribution. It is often used as the main power switch of the low-voltage switchboard and the closing switch of the motor transformer. In the event of a short circuit, the fuse is likely to blow a phase fuse, resulting in a single-phase operation, and the circuit breaker automatically trips as soon as a short circuit occurs, and the three phases are simultaneously cut off. The circuit breaker has a complicated structure and low operating frequency, and is widely used in occasions requiring high requirements.

Second, overload protection
1. When the motor is overloaded for a long time, the temperature rise of the winding exceeds its allowable value, the insulation material will become brittle, the service life will be shortened, and the motor will be damaged in severe cases. The larger the overload current, the shorter the time to allow the temperature rise. The commonly used overload protection component is a thermal relay. The thermal relay can meet such requirements: when the motor is rated current, the motor is rated temperature rise, the thermal relay does not operate; when the overload current is small, the thermal relay takes a long time to operate. When the overload current is large, the thermal relay will operate after a short time.
2. Due to the thermal inertia, the thermal relay will not be affected by the short-time overload current or short-circuit current of the motor, so the short-circuit protection must be provided while using the thermal relay overload protection. And the rated current of the short-circuit protected fuse melt should not exceed 4 times the rated current of the thermal relay heating element.

Third, over current protection
1. Overcurrent is generally caused by incorrect starting and excessive load torque, which is generally smaller than the short circuit current. It is more likely that an overcurrent will occur in the operation of the motor than in the case of a short-time operation in which the frequent forward and reverse rotation, starting, and braking are repeated.
2. For three-phase cage motors, short-circuit overcurrent will not cause serious consequences, generally do not use overcurrent protection and short circuit protection. DC motors and wound rotor asynchronous motors typically use overcurrent relays for short circuit protection.

thermal relay

Fourth, zero voltage and under voltage protection
1. When the motor is running, if the power supply voltage disappears for some reason, the motor will start automatically when the power supply voltage is restored, which may cause damage to the production equipment and even cause personal accidents. For the power grid, many motors and other electrical equipment can also start to cause unacceptable overcurrent and instantaneous network voltage drop. In order to prevent the motor from starting when the voltage is restored, the protection is called zero voltage protection. Commonly used voltage relays to achieve zero voltage protection, zero button protection can also be achieved by using buttons instead of switches.
2. When the motor is running normally, the excessive decrease of the power supply voltage will cause some electrical appliances to be released, causing the control circuit to work abnormally, which may cause an accident; excessive reduction of the power supply voltage may also cause the motor speed to drop or even stop. Therefore, it is necessary to cut off the power supply when the power supply voltage drops to a certain allowable value, which is undervoltage protection. Undervoltage protection is commonly used to achieve undervoltage protection.

Five, weak magnetic protection
The DC motor can start when the magnetic field has a certain strength. If the magnetic field is too weak, the starting current of the motor will be very large. When the DC motor is running, the magnetic field suddenly weakens or disappears, the motor speed will rise rapidly, and even the flying car will occur. Therefore, weak magnetic protection is required. The weak magnetic protection is realized by the motor excitation circuit being connected to the weak magnetic relay (current relay). In the motor operation, if the excitation current disappears or decreases a lot, the weak magnetic relay is released, and the contact cuts off the main circuit contactor coil. The power supply stops the motor and stops.

Photovoltaic power generation technology

by MAXGE

What technologies will affect the development of photovoltaic power generation in the future?

Photovoltaic power generation

UHV

It is understood that more than 70% of China’s electricity consumption is concentrated in the central and eastern regions, but the central and eastern regions lack solar energy resources and land conditions for building large-scale photovoltaic power plants. The northwest region is sparsely populated and has abundant solar energy resources, which is very suitable for building large-scale photovoltaics. Power station, but local can not absorb these photovoltaic power.
The UHV grid has obvious advantages over the existing grid. The UHV grid has greater transmission capacity and better transmission capacity, and the UHV grid has lower network loss and engineering cost. China’s UHV technology is in the world’s leading position, and the practice has fully proved the technical feasibility, operational safety, engineering economy and environmental friendliness of UHV. If China’s UHV power transmission channel is well established, the surplus electricity in the northwest region will be transported to the central and eastern regions, thus solving the problem of photovoltaic power generation.

Energy storage

Based on the fact that photovoltaic power plants can only generate electricity during the day and cannot generate electricity at night and will be affected by the weather, photovoltaic power generation has certain intermittent and random nature. It is impossible to generate electricity on the night when the demand for electricity is high, which is the biggest drawback of photovoltaic power generation. The existence of this defect not only makes the user unable to supply power through the photovoltaic power station at night, but also because of its instability, the photovoltaic power will pose a threat to the security of the power grid and the reliability of the power supply when it is connected to the power grid, which greatly affects the photovoltaic power. The promotion and long-term development of power generation.
If a photovoltaic power station can generate electricity during the day, it will save the surplus power, and it will not be powered off at night. If there is a complete energy storage technology, photovoltaic power generation will overcome the intermittent problem of power generation and provide electricity throughout the day. In addition, the energy storage system can be used for fast response FM services, which can effectively avoid the shortcomings of solar power discontinuity and uncertainty, and enhance the peak shaving capability of the power grid. As a result, the importance of energy storage technology for photovoltaic power generation is self-evident.

Photovoltaic power generation

Energy internet

For photovoltaic power generation, Energy Internet can deeply develop the information system of photovoltaic power generation, collect the design and operation data of photovoltaic power generation system, and integrate with weather and geographic data to form big data, and on this basis Load forecasting, power generation forecasting and operational control to open and optimize operational efficiency in energy production and consumption.
In addition, the global energy Internet architecture will have a positive impact on the consumption of photovoltaic power generation. In the future, photovoltaic power will not only achieve long-distance transportation, but also achieve the maximum local consumption under the intelligent operation of energy interconnection. .

In summary, UHV, energy storage, and energy Internet will have a great impact on the future development of photovoltaic power generation. The development of UHV will play a positive role in the consumption of photovoltaic power generation, or it can once again activate the development of China’s centralized photovoltaic power plants. The development of energy storage technology will make up for the inherent defects of photovoltaic power generation, enabling photovoltaic power generation to be disconnected from the power grid and provide electricity to users throughout the day, and energy storage related technologies can also eliminate the damage caused by photovoltaic power generation into the power grid. The development of energy Internet will be able to combine photovoltaic power generation with all other energy sources, and then coordinate operations in various aspects such as consumption, data analysis, and grid access, and maximize the use of new energy such as photovoltaics.