Why do Motors Need Protection?
Generally, many different types of protection are required in motor drive applications, including protecting power transistors, motors, or any part of the system. The current protection of the inverter is one of the most important items. It not only prevents any potential damage to the power transistor, but also prevents demagnetization of the motor in the event of a malfunction or when the control becomes unstable. Overcurrent protection (OCP) and short circuit protection (SCP) are two common protection methods, but there are still differences between the two. This article introduces the difference between OCP and SCP and various protection schemes.
The Difference between OCP and SCP
Short-circuit protection is part of over-current protection. Figure 1 shows the relationship between different current protections. The short circuit protection includes ground fault protection, arm short protection and phase short protection.
Figure 1. Comparison of Over-current Protection and Short-circuit Protection
The different short-circuit modes and current paths are shown in Figure 2. As shown in Figure 2(a), when the motor winding is short-circuited to the motor housing (usually grounded), or when the motor cable is short-circuited to the ground, a ground fault occurs. Figure 2(b) shows the short circuit of the bridge arm, which means that the high-side IGBT and the low-side IGBT are turned on unexpectedly at the same time and generate extremely high current. Figure 2(c) shows the phase-to-phase short circuit, which occurs when the motor windings of different phases are short-circuited. In the three examples, the current amplitude is limited by the impedance of the current path.
Figure 2. Short-circuit Current Path
How to Set OCP Points?
No matter what type of overcurrent situation is faced, how to set the protection current is very important. To solve this problem, we should first identify the vulnerable components in the system. In most cases, the IGBT will be damaged earlier than the freewheeling diode. When the inverter transfers power to the motor, overcurrent conditions are more likely to occur. Whether the OCP trip value should be set as the current that the IGBT can handle depends on the control method adopted by the system. In Volt/Hertz control, the current value at startup cannot be predicted.
For example, a permanent magnet motor used in a refrigerator with FOC has a rated current of 1A rms, but it can withstand a 120% overload for 10 minutes during the initial start-up cooling period. In this case, the peak current is 1 A rms * 120% * Sqrt(2) = 1.7 A peak. Considering the current control overshoot margin, +/- 2 A can be selected as the current feedback range in the control. Then 2.5 A can be set as the OCP trip point. Even if a 5 A IGBT with a saturation current of 30 A is used in the inverter circuit, the current trip point does not need to be set to 10 A or higher. The high current trip point may cause the motor to demagnetize.
Figure 3. The Relationship between the OCP Point and the Magnitude of Other Currents
This article introduces the difference between OCP and SCP and various protection schemes. In order to meet application requirements, appropriate protection methods should be carefully selected.
One of the disadvantages of these methods is the inability to detect ground fault current, as shown in Figure 2(a). As long as the sum is not zero, the software can calculate three-phase currents and identify ground faults. Its response speed may not be enough to prevent IGBT damage. A magnetic core, a current detection resistor on a positive DC bus rail and desaturation protection are also optional grounding protection methods.
How To Buy The Best Palm Grip Mouse
Choosing the finest palm grip mouse for gaming might be difficult because there are so many good options with high-end features on the market. Gaming mice are available in a wide range of sizes, styles, and colours. Even more so, when we consider other characteristics such as sensitivity and connection, as well as wireless or cabled versions, the range of options expands dramatically. This article was developed to assist you in selecting the best mouse before making a purchase from various shops or websites such as GamingExpert.
To identify your requirements and preferences, you may just complete a short questionnaire. It will assist you in selecting the finest palm grip gaming mouse. From the kind of games you choose to play to your play style, you should not overlook any element. This can help you figure out how many buttons you’ll need, as certain genres only require a minimum location of major buttons, while others want more.RPGs (Role Playing Games) necessitate a large number of keys for a more convenient arrangement of macro buttons, which you may match with your device based on your demands. Nevertheless, here is how you can buy the best palm grip mouse, by checking various elements that important.
The bulk of gamers place a premium on mouse speed and responsiveness. Even the tiniest input latency might have an impact on the choice. As a result, most gaming mice connect to the computer through a cable. You can still discover wireless gadgets if you’re confident they won’t tamper with your gaming experience.
Is it better to use an optical or a laser sensor?
The question of whether sensor is superior – laser or optical – is a perennial one among gamers. There is no one solution to this issue since the sensitivity of the sensor is more essential.
The sensitivity of a sensor indicates how well it senses motion. A high-end sensor can detect even the tiniest and fastest movements: if the mouse has a high sensitivity (measured in DPI), it’s the best palm grip mouse for moving the pointer without taking up much table space.
Other Types of Grip Types Mouse
The claw grip is a hybrid of the palm grip and the fingertip grasp. It is also one of the most popular grips among users. Both tip and claw grips are ideal for mice of any size and are particularly useful for little mice. The claw grip gets its name from the claw-like shape your hand takes when you wrap your fingers around the mouse.
Tip grip, often known as fingertip grip, is a less common grip. With this grip, users simply utilise their forefinger, middle finger, and ring finger on the mouse body. The palms of their hands are flying over the mouse. The other two fingers, the thumb and the tiny one, are placed on the edges of the housing and aid in the movement of the device
London poster printing options on the market
Posters are a favorite of many consumers; So, businesses crave the opportunity of London poster printing where attractive posters can be printed to enhance their business and bottom line.
Posters can be very useful in business. Attractive posters can be printed to promote the company or its products and services if the posters are properly designed with great information and illustrated layout and color. Color posters are more attractive than grayscale or black-and-white posters which are cheaper to print.
Many companies tend to use posters as a form of London advertising about their business instead of using ordinary media like television, radio, and newspapers which cost a lot more. Posters can be printed in a large format close to the size of the banner which can be hung around the city with a proper license from the local municipal authorities.
Posters of famous celebrities promoting the company or its products and services may be printed as gifts or rewards to sponsors after purchasing a certain amount of the company’s products. Consumers can choose for free and increase their sales with an attractive poster with celebrities of their choice.
Functional posters must be attractive and of the right size; They can only come through quality printing. High-quality posters reflect the high-quality products promoted by the company which won the confidence of the consumers on the products. No smart company would want to be labeled ‘penny wise and pound foolish’ with low-quality posters representing the company. Poor quality posters may be London but they will not attract sales traffic. Therefore, it costs more if consumers do not ‘bite’.
London Poster Printing of high-quality posters can be secured in several ways; Bulk printing is ideal. Therefore, companies can negotiate for a lower price with a large quantity of the same poster design.
Cheap printing costs can occur with regular printing work; Printing companies that are sure of regular income will not object to low income. So both teams won.
Another way to enjoy Poster Printing London is to have the mold or design done by another company that can offer low service costs. Thus, printing costs will be lower because there is no need to design a poster which is a high-cost service. Companies can design their own poster in-house which gives them more control over how they want to turn their poster.
With an eclectic mix of old and new, London is one of the most fascinating cities in the world, attracting visitors from all over the world. Some would say that London probably has more famous landmarks than any other city in the world. What better way to preserve your memory of such a wonderful city than to capture every moment on the black and white posters of London.
Crowded with history, London is an enchanting city with unique architecture. When captured as fine art photography, and when black and white images are combined, London’s famous landmarks and events speak for themselves in an interesting way among guests.
Many of London’s most modern buildings are instantly recognizable and a tourist attraction. The Thames Barrier, The Swiss Bank Building, The Millennium Dome, and the Millennium Bridge and Wheel Hall are unique buildings that look amazing when photographed in black and white.
While taking pictures of London taxi rides through the rain, someone walking through Trafalgar Square with the crowd in the background, or perhaps Notting Hill Carnival where people mingled with police members, the interest and unique angle can really come alive with black and white.
IPDA YouTube Channel
Are you looking for a reliable source that can teach and explain the Forex market like you are a five-year-old? We understand that trading and Forex are difficult concepts to get a hold of but also an essential part of making your mark in the market. Not everyone is interested in this hard to grasp field of study and only a few smart people take up the challenge of getting to know all there is to know about it.
If you are one of the people who would want to make profits in the market by learning the algorithm other professional traders use, then IPDATrader is the channel for you. There are a lot of YouTube channels that claim to be teaching and explaining the best market practices but IPDATrader takes the lead.
IPDATrader’s YouTube channel is not about the glam but about delivering the right pieces of knowledge to the right people at the right time. The best part about his videos is that he gets into the video almost immediately without wasting the time of his audience by beating around the bush.
Here are a few worthy reasons to be subscribed to IPDATrader which you can’t miss at any cost.
1. Unique Market Approach
The market approach discussed in IPDATrader videos is different and more effective than others. His videos are not only focused on teaching the strategies, they revolve more around the implementation and explaining the market approaches. He will let you know the ins and outs of the market. From the benefits of trading to the risks of it, everything is discussed in his videos.
His YouTube channel offers step-by-step guides to a lot of strategies and approaches which you can greatly benefit from. After going through IPDATrader’s YouTube channel you will not only learn a lot but your market analysis will become stronger.
2. Excellent Concepts Delivery
Not only does he teaches and explain the concepts in detail but he also lay out the strategies you will need while working around Forex trading. All the techniques, market strategies, and algorithmic decision-making are a part of his YouTube channel.
The concepts of each topic are cleared within his videos and by the end of it; your doubts will be cleared. IPDATrader’s videos are a treat to watch because he directly approaches the concept and gets to the nitty-gritty without adding unnecessary commentary.
3. Algorithmic and Institutional Price Delivery
IPDA or Interbank Price Delivery Algorithm is something many people want to know more about but have no means to learn it from. IPDATrader’s YouTube channel is based around this concept and is a perfect place to learn about it.
IDPATrader explains how the IPDA works, how to assess a normal trading day, how the prices are determined and evaluated, and what strategies you can implement to make the most out of a trading day. IPDA explains this algorithm in detail and you can use it to make your trading decisions more precisely.
4. High-Quality Trading Videos
The videos where the main focus is anything but teaching what is claimed are a waste of time. All the videos on IPDATrader’s YouTube channel are perfect for learners with high-quality study material and market strategies.
From learning about liquidity to risk management, and how to become a trader you always dreamed of, everything is available on this channel. IDPATrader will take you on an informative journey and increase your curiosity for the market even more.
These videos are free from any gimmickry and by the end of watching them; you will be one step ahead in your market knowledge graph. IPDATrader is determined to make you a winner trader and if you focus properly you will become one.
How Much Does A CCTV Security System Cost?
To be fair to every manufacturer of CCTV camera systems around the world, you have to face the fact that the range of the costs for having a CCTV security system varies greatly. There are some that you might get for as low as $100, but others might cost you thousands. Of course, this means that the quality of the camera and the system also defines the price if it’s high and low as well, which is why there’s the old saying that you cannot always get more for less the price.
That’s why in this article, you are going to learn what are the different factors that manipulate the price of a CCTV security system instead. In this way, you can determine the qualities that can raise the price of the CCTV system, and for you to easily find out which one is the most affordable for your preferences and budget combined. To do so, you are going to learn the costs behind the main types of CCTV systems, as well as additional costs that are outside the product already (such as labor fees).
Read about CCTV cameras at night.
Standard CCTV Camera Costs
The standard CCTV camera is the perfect one that most install for indoor purposes. These cameras usually cost around $150 to $500 a camera. Thus, when going for multiple cameras, it could cost you up to $1600 to $2000 for a system that consists of 4 to 5 cameras that can surely cover a lot of areas in your home or business.
The standard CCTV systems are also great for houses that do not have any internet, or might have a connection that’s not suitable for CCTV systems. Take note that the DVR system of the standard CCTV units do not rely on the internet for you to control and monitor the cameras.
PTZ Camera Costs
The PTZ camera, also called as pan tilt zoom cameras, are great for both indoor and outdoor purposes for its durability. These can be purchased as an analog camera or as an IP camera. These are very easy to control and allows more freedom when viewing an area where it’s mounted because you can provide controls for tilting and zooming to cover a larger area.
The PTZ camera usually costs around $100 to $400, which is way cheaper than the standard CCTV cameras since there are some PTZ cameras that cannot capture 4K resolution.
Mini Camera Costs
The Mini cameras are known to be miniature cameras that are great for indoor purposes, and can still do its job even if installed outdoors. The main advantage of mini cameras is the fact that they are very easy to conceal, and could sometimes not look like a camera so then it can provide you a more secretive type of security. These are extremely affordable as each cost around $20 to $300 only!
These also come with USB chargers, a DVD player for you to view the recordings, and some might even have nifty extra accessories such as smoke alarms and other stuff you can attach the home to conceal the mini cameras.
IP Camera Costs
The IP camera, or also known as Internet Protocol camera, relies heavily on the internet for it to work. In fact, almost all components of its system, including the DVR, operates using the internet. The IP cameras usually cost around $150 to $400 per camera, and is great in terms of its resolution since most models nowadays can capture up to 4K, and the app is extremely user-friendly even for the non-tech-savvy people.
But take note that owning an IP camera requires you to not just have a consistent internet connection, but also a very secure internet and device as well since these are prone for hackers to intrude to.
The labor costs for the cameras vary through the means of classifying if the CCTV type is wired or wireless. It’s because the setup for almost any kind of CCTV system is almost identical, such as how wires must be setup in your home or property for them to not look like they are hanging around the ceiling. At the same time, the cost for the installing wireless cameras are oftentimes low because it does not need you to make a map of wires or drill too much holes just to ensure that everything is tightly installed.
For the wired cameras, the CCTV installation cost usually goes from $100 to $200, depending on the area where the wires must be placed, as well as the number of CCTV cameras that needed to be installed. As for the wireless cameras, the cost will be around $80 to $150 only because it will only usually require drilling a certain area where the wireless camera mount will be installed, and then a bit of adjustment to the camera to ensure that it’s viewing the right angle or direction of a certain area.
With these in mind, for sure you know well now how much you need to prepare if you are finally planning to invest on securing your home, business or any other property. All you have to do now is to pick the right type of CCTV camera that suits your needs, and you will be all set to go.
Read about what makes a good CCTV Camera.
Why is Live Chat Preferred over Voice?
Every process in business needs improved interacting technology for the hype of performance. The customers expect the same logic at call centres. Connecting your customer via video call technology is the best way to interact with them. Generally, various call centres use phoning technology to improve their customer interaction. But customers from worldwide expect even more when you approach them for marketing. Live marketing through your mobiles can absorb a positive response from the customer. Do you need even more suggestions about including live marketing in your business? You can go by this page and find the comparison result of voice marketing and live marketing.
Difference between live chat and voice conversation
Which session of meeting do you feel is more interactive? Video call conference or voice call. Many of you might have the same response to this question. Yes, video call conferences are more engaging and interactive. When this live chat feature is being implemented in business, it gives even more benefits than interaction. A survey from various call centres in Australia says that live video conversation results in a more positive response compared to voice conversation. To find the reason behind the result of this survey, there are several comparison results below:
When you initiate a business, all you expect from the client is an immediate response. If you receive an immediate response at every stage, it may speed up your business. To achieve this, you must effectively approach the customer. Customers are connected to the customers in various forms, such as messages and calls where they possibly ignore them and hardly respond to them. When you connect a number of a customer under live chat, there is a high chance of a proper response. And by connecting multiple customers to one live chat, you can save and easily interact with them just like your conference. By interacting with customers through live calls, you can gain their trust, which will achieve an immediate response from the customer. This process highly helps the call centre in Australia to handle customer traffic effectively.
Convenience your customer
Through a video call interaction, you can approach the customer in a more friendly way. You can approach your customer with a smile at live interference, whereas you can greet them during a phone conversation. A feature like this gains the customer’s attention and allows them to trust the employee and your product. These factors help your employee to probably convenience them and commit to the sale.
The employer can fetch real data from the customer at the live call interface. The direct eye to contact the employee and customer may secure more approval rates from the customer side. Whereas in phone conversation there is more chance to abort the deal and move on with other products. This concept facility at live marketing increases your sale ratio and brings the effectiveness of customer services.
Texting makes them more convenient.
Most of the customer community wants their live mode of interaction, but they may feel slight trouble with an accurate response due to their pronunciation. Live chats highly support such customers by providing inter chatting facility. When the executive is stuck for clarity, they can also source accurate data with the message chat facility. Whereas at phone conversation, the customer’s face struggles to clarify their details, which may lead to wrong data information. Sourcing for incorrect data is messier and will end in the loss of a promising customer.
Through a live video interface, the employee may reach the reactions of customers and handle them accordingly. This increases interactiveness and achieves a positive response. The customer service executive can handle the customer more psychologically and push for a positive response.
If you’re continuing your customer service with a phone interface and could not yield an effective outsource, then prefer call centres in Australia with live chat interference.
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