The VFD frequency inverter for water pump

The load of the production equipment of industrial enterprises is mostly AC asynchronous motors, and the power consumption accounts for about 65% of the total power consumption of the enterprise. Especially the efficiency of the pump load is relatively low. After China joined the WTO in 2002, the enterprise must reduce costs To improve economic efficiency. In order to enhance competitiveness, in reducing production costs, saving electricity is an important economic link. For example, in a water supply station, the water supply system is adjusted according to the demand of water consumption, and the flow rate is adjusted by adjusting the valve of the pump out door. Special personnel are required to watch the valve under different circumstances. The labor intensity is large. At the same time, due to the forced throttling of the valve, the pump forms a vortex impact, which generates strong vibration and noise, which increases the unfavorable loss of the service life and maintenance of the pump. Furthermore, because the torque of the motor is basically constant, the water supply pressure formed by this adjustment method is high, causing severe throttling power loss, reducing the efficiency of the pump, and wasting electric power.

With the development of electric power technology, the frequency conversion speed regulation technology is becoming more and more perfect. The intelligent water supply control system with frequency conversion speed regulation as the core has replaced the previous high-level water tank and pressure tank and other water supply equipment. Therefore, the impact on the power grid during starting is avoided; because the average speed of the pump is reduced, the service life of pumps and valves can be extended; the water hammer effect during starting and stopping can be eliminated. Its stable and safe operation performance, simple and convenient operation mode, and complete and thoughtful functions will make the water supply realize water saving, electricity saving, manpower saving, and finally achieve the purpose of high efficiency operation.


Frequency conversion speed regulation has the following advantages:
①The slip rate is small, the slip loss is small, and the efficiency can be as high as 90 ~ 95%.
②Smooth stepless speed regulation is realized, with high precision, wide speed regulation range (0 ~ 100%), and large frequency variation range (0 ~ 50Hz).
③ The starting torque is large (up to 1.1 times of the rated value), and the soft start can reduce the impact of the starting current.
④ Improve the power factor on the grid side.
⑤Inverter can use high-speed 16-bit CPU and special large-scale integrated circuit, use software to realize V / 5 automatic adjustment, with the function of online control with computer programmable controller, easy to realize automatic control of production process.
⑥Easy installation, convenient debugging and simple operation.
⑦Not only suitable for energy-saving speed regulation of pumps and fans, but also suitable for the transformation of old equipment, especially for improving process conditions and product quality.

Solar inverter MPPT Photovoltaic Inverter Power Controller

Product introduction

Product name: photovoltaic inverter

Voltage level: 220V / 380V

Product description

The built-in MPPT controller for photovoltaic inverters has an excellent MPPT algorithm suitable for various solar panels. The main circuit uses intelligent power modules with high reliability and a conversion efficiency of about 95%. It is especially suitable for photovoltaic-driven fans and pumps load.

Three, servo drive characteristics of  machine
1.Support boost module , increase PV output voltage;

2. The speed range of the pump can be freely set according to the actual system situation;

3, soft start, reduce the top voltage spikes, with over-voltage, under-voltage, over-current, overload and other protection functions;

4. Support photovoltaic input and AC grid input;

Fourth, matters needing attention
1. Do not use the inverter for overload. For example, the inverter power is lower than the motor power, or the ordinary motor is running more than 50HZ, otherwise the inverter will skip the load protection fault frequently, and even the explosion machine, the motor may be burned due to overheating.

2. The default upper limit frequency of the inverter is 50HZ, and the anyway function is turned off by default. If you need to change it, please contact the manufacturer for after-sale or follow the instructions to operate correctly;

3. Do not connect any switches in series between the output terminals U, V, W of the inverter and the motor, including contactors. Do not use the inverter as a power source. During the operation of the inverter, you cannot suddenly turn on any equipment through the switch.

4. The lead-in distance of the inverter’s operation panel should not be too long. If it exceeds 5M, it is recommended to use an external potentiometer to adjust the speed and connect it with a shielded wire. The terminal control mode can be used for start-stop control;
5. The panel connection cable is too long and is easily affected by harmonic interference, which makes the frequency control of the inverter inaccurate and the frequency fluctuates greatly;

6. The DC input voltage should meet the recommended voltage as much as possible, otherwise the solar energy conversion rate will be reduced;

7. The AC input and DC input switches cannot be closed at the same time, otherwise the inverter or solar panel will be damaged.

VFD Single-phase 220V Input to three-phase 380V Output inverter

Single-phase 220V to three-phase 380V inverter adopts AC-DC-AC circuit structure and uses SPWM modulation control technology to convert ordinary single-phase 220V to industrial three-phase 380V. It is suitable for three-phase asynchronous motors with an output phase angle of 120 °, which fully meets the motor use standards and is suitable for various types of motor loads. The single-phase power transformer three-phase power inverter solves the inconvenience caused by the three-phase power limitation in some areas, and also solves the needs of users who cannot apply for three-phase power due to site constraints.

3.1 Technical characteristics:

· 220V input for ordinary city power, eliminating the tedious procedures of applying for three-phase power, various labor costs, and various hidden costs

· The output uses industrial three-phase power, but it is charged according to civilian single-phase power, which is economical.

· The core components are imported devices, with stable performance and long service life.

· Safe and reliable, the input single-phase power is completely electrically isolated from the output three-phase power

· Wide input voltage range design to adapt to the working environment where the mains voltage is low in all regions

Complete output protection function, with multiple protections such as over-voltage, overload, over-temperature, short-circuit, over-current, etc.

Fourth, the inverter installation environment requirements

4.1 Electrical use conditions Prevent electromagnetic interference. Due to the rectification and frequency conversion of the inverter, a lot of interference electromagnetic waves are generated around the inverter. These high-frequency electromagnetic waves have some interference with nearby instruments and instruments. Therefore, the instrument and electronic system in the cabinet should use metal shells to shield the inverter from interference with the instrument. All components should be reliably grounded. In addition, the connection between electrical components, instruments and meters should be shielded control cables, and the shielding layer should be grounded. If the electromagnetic interference is not handled properly, the entire system will often be inoperable and the control unit will malfunction or be damaged.

4.2 Ambient temperature: The ambient temperature of the inverter refers to the temperature near the section of the inverter. Because the inverter is mainly composed of high-power power electronic equipment that is susceptible to temperature, the life and reliability of the inverter depend on the temperature to a large extent, generally -10 ℃ ~ +40 ℃. In addition, the heat dissipation of the inverter itself and the extreme conditions that may occur in the surrounding environment need to be considered. Generally, there is a certain margin for the temperature.

4.3 Ambient humidity: The relative humidity requirement of the inverter to its surrounding environment is not more than 90% (no condensation on the surface).

Vibration and shock: During the installation and operation of the inverter, care must be taken to avoid vibration and shock. To avoid loose solder joints and parts of the internal components of the inverter, causing serious electrical faults and even short circuits. Therefore, it is generally required that the vibration acceleration of the installation site is limited to 0.6 g or less, and special places can be added with anti-vibration measures such as anti-vibration rubber.

4.4 Installation place: The maximum allowable output current and voltage of the inverter are affected by its heat dissipation capacity. When the altitude exceeds 1000 m, the inverter’s cooling capacity will decrease. Therefore, the inverter is generally required to be installed below 1000 m above sea level. Abnormal environmental conditions, such as exposure to excessive dust, altitude> 1000 m, etc., require special selection Structural or protective parts.

4.5 Inverter storage: In practice, the inverter is generally installed on the field equipment or installed nearby. If the site environment is poor (high temperature, humidity, dust), the inverter can be placed in the power supply under the conditions allowed by the operation. Control room. When the operator is placed on site, for the safety of the inverter, the general ambient temperature should be -10 ℃ ~ + 50 ℃. When it is used in the open air, such as oil fields, offshore oil wells, mines, etc., the winter temperature should be lower than -10 ° C, you can use an electric heater to heat it, and place the inverter in an external box; in summer, the ventilation can be enhanced when the temperature is above + 50 ° C, Insulation coating is applied to the outside of the box to reduce radiation and heat conduction. According to the actual situation on the scene, according to local conditions, artificially try to improve the environment and ensure safety. For harsh environments such as dust and fiber on site, the inverter should be placed in a box, and a filter screen should be installed at the air inlet and outlet to periodically clean and strengthen maintenance.

6.2 Notes:

· Boost inverter is a capacitor booster. For the load, it is used for light-loaded sites under 22kw. In the selection, the light-duty motor is selected by a large-level inverter, and the heavy-duty field is selected by a large-level inverter. Inverter.

· Boost inverter can only be used in three-phase asynchronous motors, not as a power source.

· Boost inverter is not suitable for the site that needs quick start and stop, and occasions with potential energy load

VFD Single-phase 220V to three-phase 380V boost inverter

First, the market demand

Due to national policies and regional restrictions, many regions will now withdraw three-phase 380V industrial power, and the cumbersome procedures for applying three-phase electricity in areas without three-phase electricity, various labor costs, and various hidden costs, etc., lead to some The region cannot use industrial 380V electricity, and general industrial equipment, such as motors, are mostly three-phase 380V. In the absence of three-phase electricity, it can not be operated. Only a way to convert single-phase 220V into three-phase 380V, but Many single-phase 220V electric three-phase 380V equipment on the market are expensive and outrageous, which makes many users in need have to be discouraged. The original machine can only be temporarily placed or placed in other places with industrial power.

Now our company has introduced a single-phase 220V input to three-phase 380V output inverter, which can drive the three-phase asynchronous motor to start up smoothly and carry out stepless speed regulation. Input power only needs single-phase 220V, output three-phase 380V, and most users can accept the price. It is about 1/10 of the price of the booster on the market. It is small in size and powerful in function. 0-650Hz can be adjusted freely. Solve the embarrassing situation that industrial equipment does not have three-phase electricity.

Second, the principle and characteristics of 220V to 380V inverter

The principle of the frequency converter is to apply the principle of frequency conversion technology and microelectronic technology. The power control equipment of the AC motor is controlled by changing the frequency of the working power of the motor, and the power frequency alternating current with constant voltage and frequency is converted into voltage or frequency. The device of alternating current is called “inverter”.

The waveform outputted by the inverter is an analog sine wave, which is mainly used for three-phase asynchronous motor speed regulation, also called frequency converter. The frequency converter is mainly composed of rectification (AC to DC), filtering, inverter (DC to AC), braking unit, drive unit, and detection unit micro processing unit. The frequency converter mainly adopts the AC-DC-AC mode (VVVF frequency conversion or vector control frequency conversion). First, the power frequency AC power supply is converted into a DC power source through a rectifier, and then the DC power source is converted into an AC power source whose frequency and voltage can be controlled to supply. electric motor.

The 220V to 380V inverter converts the power frequency AC 220V power supply into a DC power supply through a rectifier (double voltage rectification), and then converts the DC power into a three-phase 380V AC power source whose frequency and voltage can be controlled to supply the motor.

2.1 inverter function

1. It can reduce the impact on the power grid, and it will not cause the problem of excessive peak-to-valley difference.

2. The acceleration function can be controlled to smoothly accelerate according to the needs of the user;

3. The motor and equipment stop mode can be controlled, making the whole equipment and system more secure and the life expectancy will increase accordingly;

4. Control the starting current of the motor, fully reduce the starting current, and reduce the maintenance cost of the motor;

5. It can reduce the wear of mechanical transmission components, thereby reducing procurement costs and improving system stability.

6. Reduced motor starting current, providing a more reliable variable voltage and frequency.

7. Effectively reduce reactive power loss and increase the active power of the grid

8. Optimize the process and change rapidly according to the process. It can also realize the speed change through remote control PLC or other controllers.

What is the given way of the VFD? What does the frequency given mean?

Frequency given meaning and given way

Changing the output frequency of the frequency converter changes the speed of the motor. To adjust the output frequency of the inverter, the inverter must provide a signal to change the frequency. This signal is called the frequency reference signal. The so-called frequency reference mode is the way to supply the given signal of the inverter.

The inverter frequency setting mode mainly includes: panel operation given, input digital port given, analog signal given, pulse signal given and communication mode given. These given methods have their own advantages and disadvantages and must be selected according to the actual situation. The selection of the given mode is determined by the frequency setting parameter setting of the frequency converter.

Frequency setting mode parameter selection

The frequency reference mode of the inverter can be divided into panel operation reference and external port reference. The external port reference can be divided into digital port reference, analog port reference and communication interface. (Panel operation is also given by communication).

It can also be divided into digital reference and analog reference. The analog reference is divided into voltage reference and current reference.

In general, an ordinary inverter uses only one given mode to output the frequency, but in some cases, the frequency can be output in two different ways. At this time, the output frequency is the superposition of the given frequencies in two ways. .

The selection of the given mode is done with the general port configuration in conjunction with the setting of the frequency setting parameters.

What is the scope of use of the inverter?

The frequency converter is a kind of speed control device. Where it is useful to adjust the speed of the motor, especially the speed of the asynchronous motor, the inverter will be used. At present, it is mainly used on industrial equipment because the motor is the heart of the industry. The three-phase asynchronous motor occupies the majority of the proportion, so the inverter is used the most, and with the improvement of life, the inverter also uses a lot of life.

1. On the fan, it can be used to control the air volume, such as boiler drum induced draft fan, factory fan, central air conditioning fresh air fan and exhaust fan, which can adjust the wind speed according to the combustion condition or other requirements, and control the supply air volume. The role of the valve size.

2, the pump industry, industrial recycling water, life inverter constant pressure water supply, sewage treatment, the same reason some chemical liquid raw materials will also be used in the transmission of the frequency converter, these are also used to control some liquid flow or pressure use. As with the fan control, the accuracy required for the inverter is not high, and a dedicated fan-pump type inverter is used, which is relatively cheap and can meet the requirements.

3. Some transmission fields are used to control the transmission, such as conveyor belts and transmission rollers. It is necessary to control the transmission speed of materials to synchronize the overall production line. In this case, a general-purpose inverter can be used.

4, mixing, mixing, grinding, crushing, extrusion, throwing and some rolling occasions, need to let the equipment “bite” each other, so that the material is fully mixed, this process also needs control process, need to use the frequency converter to complete General general type can also meet the requirements.

5, hanging, hoisting, rewinding and other occasions, the inverter needs to achieve a certain synchronization and tension control, the accuracy requirements are relatively high, you need to use vector inverter or direct torque control type inverter.

6, air conditioning compressors and air compressors and other occasions, the current use of synchronous motors, control algorithms and asynchronous reality are similar, but also variable frequency speed control, just because of the motor, the efficiency is relatively high.

7. Automobile and motorcycle industry, from trains to electric vehicles, three-wheel electric vehicles and two-wheeled battery vehicles, vehicles, currently have inverters in use.

8. In the processing industry, robots, etc., the inverter can be used as a spindle or an important rotary table motor. If the servo is also regarded as a special inverter, it is used by each axis.

What is the meaning of torque, torque and torque that the inverter often says?

Torque in physics refers to the tendency of a force to cause an object to rotate about a rotating axis or fulcrum. Torque, the physical quantity of force acting on an object, can be divided into the moment of the force versus the axis and the moment of the force versus the point. The rotational torque is also called torque or torque.


Where L is the distance vector from the axis of rotation to the point of force, and F is the vector force. The moment is also a vector, and the unit of torque is Newton-meter.

What is the meaning of torque, torque and torque that the inverter often says?

The concept of torque can be seen everywhere in our daily lives, from the seesaws I played as a child, to the famous quote of Archimedes – “Give me a fulcrum, I will shake the whole earth”, which all reflect the meaning of the moment. Similarly, torque is ubiquitous in cars, but through a series of rotations of the drive shaft, the torque here is called torque. The amount of torque directly affects the power output efficiency, energy consumption, and even operating life and safety performance.

What is the meaning of torque, torque and torque that the inverter often says?
The difference between torque and torque:
The range covered by the two is different. The range of the torque is wider. The result of multiplying the force by the force arm can be called the moment, but the torque generally refers to the torque received by the rotating object. For example, when a wheel rotates, the product of ground friction and wheel radius is generally referred to as torque, but is also a type of torque. The use of a bottle to open a beer bottle is generally called torque, but can not be said to be torque.
The difference between torque and torque:
The couple or torque that causes the machine component to rotate (including the tendency to rotate) is called the rotational torque, referred to as torque. Any component under the action of torque must have some degree of torsional deformation (which may include elastic deformation and plastic deformation). Therefore, it is customary to often refer to the turning moment as the torsional moment, referred to as the torque. Both can be mixed in any field, but torque is more common in engineering.

Torque, torque and torque are actually the same in the motor. Generally, in the same article or the same book, the above three nouns use only one, and it is rare to see two or more at the same time. Although the three words are used in different occasions, in the motor, it refers to the driving “moment” generated by the rotor winding in the motor that can be used to drive the mechanical load. The so-called “moment” refers to the force and the fulcrum and force. The product of the distance perpendicular to the direction.

Precautions for the surrounding environment of the inverter

The peripheral components of the inverter mainly include cables, contactors, air-openers, reactors, filters, and braking resistors. Whether the selection of the peripheral components of the inverter is correct or appropriate also directly affects the normal use of the inverter and the service life of the inverter. Therefore, after selecting the inverter, we must also correctly select its peripheral components. Below we will briefly explain the precautions for the selection of peripheral equipment.
Line breaker setting and selection
In order to protect the primary wiring on the power supply side of the inverter, install a wiring breaker. The choice of circuit breaker depends on the power factor on the power supply side (varies with supply voltage, output frequency, load). The operating characteristics are affected by the high-frequency current, and it is necessary to select a large capacity.
Line contactor
The inverter can be used without a line contactor. The line contactor can be stopped, but the brake function of the inverter will not be used.
Motor side contactor
If a contactor is provided between the inverter and the motor, it is in principle not allowed to switch during operation. When the inverter is connected during operation, there will be a large inrush current, so the inverter overcurrent protection action. When setting the contactor for switching to the grid, be sure to switch after the inverter stops output and use the speed search function as appropriate.
Thermal relay setting
In order to prevent the motor from overheating, the inverter has electronic thermal protection. However, when one inverter drives multiple motors and multi-stage motors, set a thermal relay between the inverter and the motor. The thermal relay is set to 1 times the motor nameplate at 50 Hz and 1.1 times at 60 Hz.
Power factor improvement
To improve the power factor, you can insert an AC reactor into the inverter’s incoming line or add a DC reactor to the DC loop. When the inverter output side is connected to the capacitor filter for improving the power factor, there is a danger of damage and overheating due to the high-frequency current output from the inverter. In addition, the inverter will overcurrent and cause current protection. Please do not connect the capacitor filter.
About radio interference
There is a high-frequency component in the output (main circuit) of the inverter, which can cause interference to communication devices (such as AM radios) used near the inverter. Filters can be installed to reduce interference. In addition, it is also effective to ground the inverter and the motor and the power supply wiring on the metal pipe.
Power cable wire diameter and wiring distance
When the wiring distance between the inverter and the motor is long (especially at low frequency output), the motor torque will drop due to the cable voltage drop; use a sufficiently thick cable wiring; when the operator is installed elsewhere, use a dedicated connection. Cable; when operating remotely, the distance between analog, control line and inverter should be controlled within 50 meters; the control signal should be properly shielded from ground.

Causes and treatment methods for vibration and noise generated by the inverter

There are also some problems in the process of the inverter. For example, vibration and noise are the problems that often occur when the inverter is working. What is the cause of vibration and noise in the inverter? What are the problems? The solution is to introduce the causes and treatment methods of vibration and noise generated by the inverter.

The reason for vibration and noise is that when the inverter is working, the magnetic field caused by the higher harmonics in the output waveform generates electromagnetic force for many mechanical components. The frequency of the power can always be close to or coincide with the natural frequency of some mechanical components. Causes resonance.

The higher harmonics that have a large influence on the vibration are mainly lower harmonic components, and have a greater influence in the PAM (Pulse Amplitude Modulation), the pulse amplitude modulation method and the square wave PWM mode. However, when the sinusoidal PWM method is used, the low-order harmonic components are small and the influence is small. When the inverter is used to drive the motor, since the output voltage and current contain higher harmonic components, the higher harmonic flux of the air gap increases, so the noise increases. The electromagnetic noise instrumentation world network gives the following characteristics: Since the low-order harmonic component in the inverter output resonates with the rotor’s inherent mechanical frequency, the noise near the natural frequency of the rotor increases. The higher harmonic components in the inverter output resonate with the core housing and the like, and the noise near the respective natural frequencies of these components increases. The noise generated by the drive motor of the inverter, especially the harsh noise, is related to the switching frequency of the PWM control, especially in the low frequency region. Using frequency converter speed regulation will generate noise and vibration, which is the influence of high harmonic components in the output waveform of the inverter. As the operating frequency changes, the fundamental component and the higher harmonic components all vary over a wide range, which is likely to cause resonance with various parts of the motor.

Vibration and noise processing methods to reduce or eliminate vibration, you can connect the AC reactor on the output side of the inverter to absorb the higher harmonic current components in the inverter output current.

When using the PAM mode or the square wave PWM mode inverter, the sine wave PWM mode inverter can be used instead to reduce the ripple torque. In order to prevent the vibration of the mechanical system connected to the motor and the load, the entire system must not resonate with the electromagnetic force generated by the motor. The following measures are generally used to suppress and reduce noise: an AC reactor is connected to the output side of the inverter. If the electromagnetic torque has a margin, the U/f can be made smaller. When using a special motor, such as when the noise level of the lower frequency is more serious, check the resonance with the natural frequency of the shaft system (including the load).

How does the inverter control the motor speed and save energy?

1. Why is the rotational speed of the motor freely changeable?
Motor rotation speed unit: r/min The number of rotations per minute can also be expressed as rpm. For example: 2-pole motor 50Hz 3000 [r/min] 4-pole motor 50Hz 1500 [r/min]

Conclusion: The rotational speed of the motor is proportional to the frequency

The rotational speed of an inductive AC motor (hereinafter referred to simply as a motor) is approximately determined by the number of poles and frequency of the motor. The number of poles of the motor is fixed by the working principle of the motor. Since the pole value is not a continuous value (a multiple of 2, for example, the number of poles is 2, 4, 6), it is generally uncomfortable and the speed of the motor is adjusted by changing the value.

In addition, the frequency can be supplied to the motor after being adjusted outside the motor, so that the rotational speed of the motor can be freely controlled.

Therefore, the inverter for the purpose of controlling the frequency is the preferred device for the motor speed control device.

n = 60f/p

n: synchronization speed

f: power frequency

p: motor pole pairs

Conclusion: Changing frequency and voltage is the optimal motor control method

If only the frequency is changed without changing the voltage, the frequency will decrease and the motor will be over-voltage (overexcitation), causing the motor to be burned out. Therefore, the inverter must change the voltage at the same time while changing the frequency. When the output frequency is above the rated frequency, the voltage cannot continue to increase, and the maximum can only be equal to the rated voltage of the motor.

For example, in order to reduce the rotational speed of the motor by half, change the output frequency of the inverter from 50Hz to 25Hz, then the output voltage of the inverter needs to be changed from 400V to about 200V.
2. What is the output torque when the motor’s rotational speed (frequency) changes?
The starting torque and maximum torque when the inverter is driven are less than that of the direct-frequency power supply. When the motor is powered by the commercial power supply, the starting and acceleration shocks are large, and when the inverter is used for power supply, these impacts are weaker. A direct start of the power frequency produces a large starting and starting current. When the inverter is used, the output voltage and frequency of the inverter are gradually added to the motor, so the starting current and impact of the motor are smaller. Generally, the torque produced by the motor is reduced as the frequency decreases (the speed decreases). The reduced actual data is given in some of the drive manuals.

By using a flux vector controlled inverter, the torque of the motor at low speeds is improved, and even in the low speed range, the motor can output sufficient torque.
3. When the inverter is adjusted to a frequency greater than 50Hz, the output torque of the motor will decrease.
The usual motor is designed and manufactured at a voltage of 50 Hz, and its rated torque is also given within this voltage range. Therefore, the speed regulation below the rated frequency is called constant torque speed regulation. (T=Te, P<=Pe) When the inverter output frequency is greater than 50Hz, the torque generated by the motor should be linearly inversely proportional to the frequency. decline. When the motor is running at a frequency greater than 50 Hz, the size of the motor load must be considered to prevent the motor from outputting insufficient torque.

For example, the torque generated by the motor at 100 Hz is reduced to approximately 1/2 of the torque at 50 Hz.

Therefore, the speed regulation above the rated frequency is called constant power speed regulation. (P=Ue*Ie)
4. Application of inverter above 50Hz
As you know, the rated voltage and current rating of a particular motor are constant. If the inverter and motor are rated: 15kW/380V/30A, the motor can work above 50Hz. When the speed is 50Hz, the output voltage of the inverter is 380V, and the current is 30A. At this time, if the output frequency is increased to 60Hz, the maximum output voltage of the inverter can only be 380V/30A. Obviously, the output power is unchanged. So we call it constant power speed regulation.

What is the torque situation at this time?

Because P = wT (w: angular velocity, T: torque). Because P does not change, w increases, so the torque will decrease accordingly.

We can also look at another angle:

The stator voltage of the motor U = E + I*R (I is the current, R is the electronic resistance, and E is the induced potential)

It can be seen that when U, I are unchanged, E does not change.

And E = k*f*X, (k: constant, f: frequency, X: flux), so when f is from 50–>60Hz, X will decrease accordingly.

For the motor, T = K * I * X, (K: constant, I: current, X: flux), so the torque T will decrease as the flux X decreases.

Meanwhile, when it is less than 50 Hz, since I*R is small, when U/f=E/f is constant, the magnetic flux (X) is constant. The torque T is proportional to the current. This is why the inverter is usually used. Overcurrent capability to describe its overload (torque) capability. Also known as constant torque regulation (rated current is constant –> maximum torque is constant)

Conclusion: When the inverter output frequency increases from above 50Hz, the output torque of the motor will decrease.
5. Other factors related to output torque
The heat and heat dissipation capacity determine the output current capability of the inverter, which affects the output torque capability of the inverter. Carrier frequency: Generally, the rated current of the inverter is the highest carrier frequency, and the value of continuous output can be guaranteed at the highest ambient temperature. When the carrier frequency is reduced, the current of the motor will not be affected. However, the heat of the components will decrease. Ambient temperature: It is not like increasing the protection current value of the inverter because it detects that the ambient temperature is low.

Altitude: The altitude increases, which has an effect on heat dissipation and insulation performance. Generally, it can be ignored below 1000m. Above 5% per 1000m can be used.

Need help? Email Us Here! Chat With Us Now!

← Prev Step

Thanks for contacting us. We'll get back to you as soon as we can.

Please provide a valid name, email, and question.

Powered by LivelyChat
Powered by LivelyChat Delete History