1. Active power - in the process of generating and transmitting alternating current energy, the part of energy used to convert into electromagnetic methods is called active power
2. Reactive power - in the process of generating and transmitting alternating current energy, the part of energy used for the electromagnetic field exchange in the circuit is called reactive power
3. Power system - the whole composed of generators, power distribution devices, step-up and step-down substations, power lines and power users is called the power system. Neutral point displacement: In a three-phase circuit, if the supply voltage is symmetrical with the three-phase load, if the three-phase load is also symmetrical, then the voltage at the neutral point is zero regardless of whether there is a neutral point or not. However, if the three-phase load is asymmetrical, and there is no neutral or the neutral impedance is large, then the neutral point will present a voltage, which is called the neutral displacement phenomenon.
4. Operating overvoltage - the transient voltage increase caused by circuit breaker opening and closing operation and short circuit or grounding fault is called operating overvoltage;
5. Resonant overvoltage - due to the operation of the circuit breaker, the power grid circuit is divided or the core components tend to be saturated, resulting in the inductive reactance and capacitive reactance of a certain circuit to meet the resonance conditions, which may cause the voltage to rise due to resonance, which is called resonant overvoltage.
6. Electrical main wiring - mainly refers to the circuit of transmitting electric energy that is planned to meet the requirements of the predetermined power transmission method and operation in the power plant, substation and power system, and indicates the interconnection between high-voltage electrical equipment.
7. Double bus wiring - it has two sets of busbars: working bus I and spare bus l. Each circuit is connected to two sets of buses by a circuit breaker and two sets of barrier switches, and the bus is connected by a bus connection circuit breaker (referred to as bus connection), which is called double bus wiring.
8. Wiring of one and a half circuit breakers - every two components (outgoing or power supply) are connected in series to two groups of bus bars with three circuit breakers, which is called a half circuit breaker wiring, also known as 3/2 wiring.
9. Power consumption of the plant - in the process of starting, running, decommissioning and overhauling the power plant, there are a large number of mechanical equipment dragged by electric motors to ensure the normal operation of the main equipment of the unit and auxiliary equipment such as coal transportation, coal crushing, ash removal, dust removal and water treatment. These motors and the operation, operation, test, maintenance, lighting and other electrical equipment of the whole plant are attributed to the plant load, and the total power consumption is collectively referred to as the factory electricity.
10. Plant electricity consumption rate - the percentage of power consumption of the plant in the total power generation of the power plant, which is called the power consumption rate of the plant. The power consumption rate of the plant is one of the main economic indicators of the operation of the power plant.
11. Constant load - the motor used in continuous operation every day;
12. Infrequent load - the load that is only used during maintenance, accident or furnace start-up and stop;
13. Continuous load - the load of more than 2 hours of continuous operation each time;
14. Short-term load - the load that only runs for 10-120min each time;
15. Intermittent load - repeated periodic operation, each cycle of which does not exceed the load of 10min.
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The role of LS electric contactors
1. It is often used in electric motors as control targets.
2. It is used to control power loads such as factory equipment, electric heaters, working machines and various power units.
3. It has the effect of low voltage release protection.
4. It is suitable for frequent operation and long-distance control, and is an automatic operation.
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Inverter applications and common loads – LS generates electricity
1. Air conditioning load
Office buildings, shopping malls and some supermarkets and factories have central air conditioning, and the electricity consumption of air conditioning is very large during the peak electricity consumption in summer. In hot weather, the electricity consumption of air conditioners in Beijing, Shanghai and Shenzhen accounts for more than 40% of peak electricity. Therefore, with inverter equipment, drag the air conditioning system ...
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Single-table driver for HLP2B
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Inverter fault diagnosis - LS power generation
1. How to distinguish between heavy and light faults
When there is a problem with the light, the system announces the alarm signal and the fault indicator flashes. When there is a serious problem, the system will announce the problem indicator, the problem indicator will always be on, together announce the order to break the high voltage and stop closing, and store the problem ...
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Introduction of LS inverter IGXA series
LS inverter, the full name of LS AC inverter governor, converts direct current into alternating current by providing a variety of use configurations, and controls the speed of the motor by changing the voltage and frequency of the general power input to meet different industrial needs, so as to complete the energy saving and environmental protection of the automation system. ...
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LS MASTER-K120S series PLC features and advantages
(1) This series is divided into two types: economic type and standard type, which can meet the requirements of different customers:
Economical: 10/14/20/30 points (10/14 points with 2 built-in analog potentiometers), up to 70 points.
Standard type: 20/30/40/60 point DR/DRT (2-axis position ...
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Precautions for the maintenance of the inverter of the tensile testing machine - LS generates electricity
In the course of regularly checking the variable-frequency drive (VFD) of the tensile testing machine, we can visually check the operating status directly from the outside.
(1) The ambient temperature is normal, and it is required to be between -10°C and +40 ...
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The cause of the broken shaft of the motor - LS generates electricity
1. Improper device:
The motor is not concentrious with the equipment being dragged, resulting in excessive radial load on the motor, which eventually leads to metal exhaustion. When the radial load on the extension end of the motor shaft is too large, it will cause the motor shaft to have zigzag deformation in the radial direction. When the motor rotates, the shaft's ...
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Why can't the inverter be equipped with a leakage protector - power generation
When using an inverter, a leakage maintainer must not be used. This is a major principle of the use of frequency converters.
Some users choose the corresponding leakage maintainer for the inverter when using the inverter. *The result is: the inverter moves together ...
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The main structure of LS power AC contactor
The operating principle of the contactor is: when the contactor coil is energized, the coil current will generate a magnetic field, and the generated magnetic field will make the static iron core attract the moving core with electromagnetic attraction, and drive the communication contactor point action, the normally closed contact is disconnected, and the normally open contact is closed, and the two are linked. When the coil is de-energized ...
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Common faults and countermeasures of power inverters
1. OC failure
Like other inverters, overcurrent alarm is also a common fault of power inverter, in addition to the reasons for parameter settings such as acceleration and deceleration time, there are mainly the following possibilities in hardware: damage to high-power modules may cause OC alarm, low-power economical inverter ...
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A common fatal form of failure of the terminal block - LS power generation
1. Poor touch
The metal conductor inside the terminal block is the core part of the terminal, which transmits the voltage, current or signal from the external wire or cable to the touch piece corresponding to the connector it matches. Therefore, it is necessary for the touch parts to have excellent structure, stable and reliable touch firmness.
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The difference between voltage type and current type inverter - LS generates electricity
The differences between voltage type and current type inverter are mainly manifested in:
(1) the load of the buffer inverter of reactive power is an asynchronous motor, which is an inductive load, and in addition to transmitting active power between the intermediate DC link and the motor, there is also the exchange of reactive power. Because power electronic switches ...
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The application of the inverter to supply power to the motor has encountered a problem
A frequency converter is a device that converts power to other frequencies of power supply. The power frequency of our country is 50Hz, in the field of motors, in order to change the speed of the motor, or other performance changes, many motors choose inverter power supply.
...
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The touch screen controls the inverter steps
1. The touch screen is controlled by PLC inverter
1. At present, the general control of the inverter needs to use PLC to communicate with the inverter, read the information of the inverter, and then the touch screen communicates with the PLC in order to complete the control of the inverter to start, stop, and monitor the operation of the inverter.
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DC reactor for inverter and design calculation - LS power generation
The DC reactor for the inverter is also called the flat wave reactor, which is connected in series in the DC bus (terminals P1 and P+). The main thing is to reduce the higher harmonic component of the input current and improve the power factor of the input power supply (to 0.95). This reactor can be used at the same time as the AC reactor, and the inverter has high power ...
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The basic problem of LS electric molded case circuit breaker
Rated current of LS molded case circuit breaker:
Now in the process of using molded case circuit breakers, it is necessary to understand the rated current of molded case circuit breakers, and the rated current of molded case circuit breakers generally has more than a dozen, mainly 16A, 25 A, 30A, and the high may reach 630A.
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Classification of the nature of DC power supply of inverter - LS power generation
A frequency converter is actually an inverter. It starts by turning alternating current into direct current. Then the direct current is switched on and off with electronic components. Becomes alternating current. Thyristors for general inverters with larger power. And set up a device with adjustable frequency. Make the frequency adjustable within a certain range. Used to control ...
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Inverter external potentiometer connection method - LS power generation
The two wires are connected to the resistor, and the other wire is connected to the adjustment terminal.
The red thread is attached to the blackhead and inserted in a small hole.
Connect both ends of the IR potentiometer to +10V and ACM, and slide the termination to the voltage input terminal AVI.
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Introduction to electrical equipment - LS Electricity
According to the requirements of safe, high-quality, reliable and economical operation of the production, transforming, transportation, distribution and use of electric energy in power plants and substations, the following electrical equipment is mainly included.
1. Primary equipment
Directly involved in production, ...
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