Network converter. Switching power supplies - inverters. Single-cycle UPS circuit

Switching secondary power supplies are widely used in household and industrial equipment. Switching power supplies generate direct and alternating voltages necessary for power supply of equipment units through a key conversion of the rectified mains voltage of 220 volts and 50 hertz.
The advantage of the UPS over a traditional transformer power supply is provided by replacing the power transformer operating at an industrial network frequency of 50 hertz with a small-sized pulse transformer operating at 16 – 40 kilohertz, as well as the use of pulse methods for stabilizing secondary voltages instead of compensation ones. This leads to a reduction in the weight and dimensions of the product by 2-3 times and an increase in Source efficiency up to 80 - 90% , which means it further saves electrical energy.
The key stages of the voltage converter are built using single-cycle and push-pull circuits.
In old transistor TVs, due to their specific circuit design, single-cycle UPSs were used.
Single-cycle UPSs are also used in low-power devices up to 50 watt and more.
A good example is the various chargers for powering mobile phones, laptops and much more. They are widely used due to their ease of manufacture, small size and high reliability.


The figure shows the charger board for a mobile phone. It converts alternating voltage 110 - 220 volts into direct voltage 5 volts.

Increasing the power of single-cycle UPSs turns out to be ineffective due to the increase in overall dimensions and weight of the pulse transformer (compared to a push-pull circuit) and increased requirements for the key transistor (high voltage and current).
Push-pull UPSs are used at capacities from a few watts to hundreds of watts , due to their simplicity and cost-effectiveness.
Example of using a push-pull converter:

Energy saving lamps with a power of 20 watts.

Powerful computer power supplies

Single-cycle UPS circuit

A single-cycle UPS circuit is a converter of alternating mains voltage (or direct battery voltage) of one value into direct (rectified) voltage of another value.
An HF voltage generator with a frequency of 20–100 kilohertz can be self-excited (self-oscillator) or externally excited (additional generator).
Low-power (up to 10 watts) and simple UPSs mainly use a self-exciting self-oscillating converter.
See the diagram of a simple single-ended, self-excited, switching power supply.


A single-cycle UPS circuit consists of rectifier(D1 – D4) with smoothing capacitor C1. In it, the mains voltage of 220 volts is converted into a constant voltage of 310 volts. Then using generator and pulse voltage (transistor T, transformer Tr), rectangular pulses are generated. From the secondary winding, rectangular pulses arrive at rectifier(D6) with a smoothing capacitor (C5), a constant voltage is obtained.
The voltage conversion itself occurs on a ferrite transformer. The output voltage depends on the ratio of turns in the primary and secondary windings of the transformer.
A significant disadvantage of the single-cycle converter circuit is the high self-induction voltage induced in the primary winding of the transformer, which exceeds the input supply voltage Ep by 2-4 times. In such circuits, transistors are needed that have a maximum collector-emitter voltage equal to 700-1000 volts.

Various methods are used to reduce voltage surges at the transistor collector:
- RC circuits (C2, R3) are switched on parallel to the primary winding of the transformer and capacitor C4 in the secondary winding circuit.
— when using additional devices for stabilizing the output voltage, for example, pulse-width modulation (PWM), it is possible to operate a single-cycle UPS when the connected load changes within a wide range (from P = 0 to Pmax) with a constant output voltage.
Other technical methods for protecting the key transistor from overvoltage are also used.

Pros and cons of a single-cycle UPS circuit.

Pros:
- one key transistor in the circuit,
- the circuit is simpler than push-pull.

Minuses:
— magnetization of the ferrite core occurs only in one polarity (passive demagnetization of the core), as a result of which the magnetic induction of the core is not fully used. The ferrite core is not fully utilized in terms of power. A gap is required in the magnetic core.
- with average current consumption from the network, the current through the transistor is n-times greater (depending on the duty cycle of the pulses) and therefore it is necessary to select a transistor with a obviously larger maximum current.
- large overvoltages occur on the circuit elements, reaching 700 - 1000 volts.
— it is necessary to apply special overvoltage protection measures on circuit elements.

Push-pull UPS circuit

The push-pull self-generating UPS circuit consists of a 220-volt AC input voltage rectifier, a generator starting device, a rectangular pulse generator and an output voltage rectifier with a filter capacitor.
The figure shows the simplest, most common push-pull circuit of a self-oscillating, pulse converter - inverter, half-bridge circuit.

Compared to the circuit of a single-cycle self-oscillator, a push-pull self-oscillator has a more complex circuit.

Added:

— device for automatically starting the pulse generator;
- another key transistor;
— additional transformer Tr1, for controlling key transistors;
— two half-bridge capacitors (C3, C4);
— two diodes (D5, D8) to protect transistors from breakdown.

The push-pull UPS circuit has a number of advantages over the single-cycle circuit:

— the ferrite core of the output transformer Tr2 operates with active magnetization reversal (the magnetic core is most fully used in terms of power);
— the collector-emitter voltage Uek on each transistor does not exceed the power source voltage of 310 volts;
— when the load current changes from I = 0 to Imax, the output voltage changes slightly;
— high voltage surges in the primary winding are very small, and the level of radiated interference is correspondingly lower

Despite the increased complexity, the push-pull circuit, in comparison with the single-stroke circuit, is easier to set up and operate.

The 1182EM2 microcircuit is a representative of the class of high-voltage electronic circuits. The main purpose of the IC is the direct conversion of 220 V alternating voltage into rectified direct voltage.
Thanks to the unique technology, it is possible to use the microcircuit for AC power up to 264 V.

Features of application

• Wide AC input voltage range from 18V to 264V
• Wide input frequency range from 50 to 400 Hz
• DC output current limit: 100 mA

The KR1182EM2 microcircuit is designed to create compact power supplies from an alternating current network of a non-isolated type, for example, for electric razor motors, auxiliary motors for powerful network switching power supplies, etc. In Fig. 1 shows a functional electrical diagram. A typical switching circuit and timing diagram of the microcircuit are shown in Fig. 2.3.

The microcircuit contains 4 high-voltage diodes, a key stabilizer, a protective stabilizer and an output diode. The key stabilizer, through an external current-limiting resistor R1 and input diodes, connects an external storage capacitor C3 to the AC mains until it is charged to a voltage determined by an external zener diode with a breakdown voltage of less than 70 V, connected between pins 7 and 5 of the microcircuit. If an external zener diode is not installed, then this voltage will be determined by the internal protective zener diode and will be 70-90 V. Then the stabilizer disconnects the capacitance from the network until the next half-wave of the mains voltage. During the remaining cycle time, capacitor C3 supplies the load. The next turn-on cycle of the stabilizer occurs after the input voltage passes through 0 V when the voltage at its input reaches approximately 1.5 V more than that at the storage capacitor. The switching frequency of the stabilizer, that is, the frequency of charging the capacitor, is determined by the switching circuit of the input diodes - half-wave or full-wave, and corresponds to the frequency or double the frequency of the input voltage. This control principle allows the microcircuit to be used only when connected to an alternating current network and ensures the normal operation of the microcircuit when the input voltage changes from 18 to 264 V and the input voltage frequency from 48 to 440 Hz. At the input of the circuit, a constant voltage is obtained that has a ripple with a frequency or double the frequency of the input voltage and a value directly proportional to the load current and inversely proportional to capacitance C3.
The output diode is designed to suppress negative voltage surges when operating an inductive load.

BASIC CONNECTION DIAGRAMS

A typical switching circuit makes it possible to implement full-wave power supplies for a wide range of input voltages and output currents.
Below is a list of external components, a description of their purpose and recommended values. Not all of these may be required for any given power source.
F1 - Fuse. Needed to protect the microcircuit and the load in an emergency. The recommended fuse rating is 500 mA.
R1 - Limiting resistor. Limits the current of the key stabilizer and the charging current of capacitor C3. The peak current value Ui peak/R1 should not exceed 2.5A.
The rating and power of R1 are selected in accordance with the intended scope of application, provided that the maximum charge current is not exceeded. It is advisable to use a resistor with a negative temperature coefficient. Recommended value R1=150 Ohm.
C1 - Filter capacitor. R1 and C1 form a filter that smoothes out high-frequency surges in the input voltage. Recommended C1=0.05uF.
MON - Overvoltage protection. It is possible to use a varistor for alternating voltages up to 120 V or a 500 V discharge lamp for alternating voltages up to 240 V.
C2 - Delay capacitor. The connection of the power source to the mains voltage, in general, is not synchronized with it. This is most likely to occur when the input voltage is close to peak voltage or even at higher voltages due to network surges.
Since the storage capacitor is completely discharged, a larger current will flow through the microcircuit compared to the steady state. To increase the reliability of the source and without compromising its characteristics, it is advisable to block the activation of the stabilizer until the next half-wave, which is guaranteed by connecting a 150 pF capacitor C2 with an operating voltage 10 V higher than the output one.

C3 - Storage capacitor. This capacitor is charged twice during the period of the input voltage, the rest of the time it powers the load. The capacitance of the capacitor is selected proportional to the required maximum load current. Increasing the capacitance C3 reduces the output voltage ripple. For maximum load current, a 470 µF capacitor with an operating voltage 10 V higher than the output voltage is recommended.
VD1 - zener diode. It sets the output voltage level. In its absence, the internal protective zener diode operates at 70-90 V.

If it is necessary to turn on and off the constant output voltage without turning off the input network voltage, it is proposed to connect a mechanical switch, optocoupler or open-collector transistor to pin 7.

For galvanic isolation from the AC mains, it is possible to use a separating transformer.
If a common bus is required for the load and mains voltage, then it is possible to turn on the circuit in a half-wave operating mode.

ATTENTION!!!

Compared to conventional transformer-based power supplies, the power supply based on the KR1182EM2 microcircuit does not have galvanic isolation. When developing the desired design, remember the need for adequate insulation. Any connected circuit must be treated as non-isolated.

MAXIMUM PERMISSIBLE ELECTRICAL MODES

CJSC “STC of Circuit Engineering and Integrated Technologies”

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When developing the device described below, the task was to create a small-sized network power supply with high efficiency, capable of delivering a power of 1...3.5 W to a load galvanically unconnected to the network. These requirements are fully met by a single-cycle pulse stabilized voltage converter that transfers energy to the secondary circuit in pauses between current pulses in the primary winding of the isolation transformer. One of the options for such a device is brought to the attention of readers (Fig. 4.3).

Main technical characteristics:

Output voltage, V................................................... ............±12

Total output power, W................................................... 3.5

Conversion frequency, kHz................................................... ......20

Limits for changes in network voltage,

at which the output voltage changes

by no more than 1%, V................................................... ...................210...250.

The device includes a voltage rectifier (VD1) with a smoothing filter (R4, SZ, C4), a master oscillator (DDI.1...DDI.3) with a trigger circuit (R17, C7), a rectangular pulse shaper (DD1.4. ..DD1.6, VT2, VT4), electronic key (VT3), pulse transformer (T1), adjustable current source (VT5), load short circuit protection device (R10, VT1), three rectifiers (VD2...VD4 ) and the same number of filter capacitors (C9...C11). Capacitors CI, C2 prevent interference from the conversion frequency from entering the network.

When the device is connected to the network, capacitors S3, C4 and C7 begin to charge. After the voltage on the last of them reaches approximately 3 V, the master oscillator (DDI.1...DDI.3) is self-excited. The repetition rate of its pulses (depending on the time constant of the circuit R7, C5) is about 20 kHz, the shape resembles a sawtooth. The shaper (DDI.4...DDI.6, VT2, VT4) converts them into rectangular oscillations. Since the sequences of pulses on the bases of transistors VT2 and VT4 are antiphase, they open strictly alternately, which ensures minimal opening and closing time of transistor VT3. When this transistor is open, a linearly increasing current flows through winding I and transformer T1 accumulates energy, and when it is closed (there is no current through the primary winding), the energy accumulated by the transformer is converted into the current of the secondary windings III...V.

After several cycles of generator operation, a voltage of 8... 10 V is established on capacitor C7. The output voltage of the converter is stabilized by an adjustable current source made on transistors of the VT5 assembly (VT5.2 is used as a zener diode). When the voltage fluctuates in the network or on the load, the voltage on winding II changes and the adjustable current source, acting on the driver, changes the duty cycle of rectangular pulses based on transistor VT3.

When the pulse current through resistor R10 increases above a certain threshold value, transistor VT1 opens and discharges capacitor C6 (which serves to prevent false operation of the protective device from short surges of current that occur when the converter is turned on, as well as during switching of transistor VT3). As a result, the pulses of the master oscillator stop arriving at the base of transistor VT3 and the converter stops working. When the overload is eliminated, the device starts again 0.8...2 s after charging capacitors C6 and C7.

The windings of the T1 pulse transformer are wound on a polystyrene frame with PEV-2-0.12 wire and placed in a B30 armored magnetic core made of 2000NM ferrite. Windings 1.1 and 1.2 contain 220 turns each, windings II, III, IV and V - 19, 18, 9 and 33 turns, respectively. First, winding 1.2 is wound, then windings I, IV, III, V and, finally, winding 1.1. Between windings II, IV, V and 1.1, electrostatic screens are placed in the form of one layer (approximately 65 turns) of PEV-2-0.12 wire. When assembling the transformer, a 0.1 mm thick varnished cloth gasket is inserted between the ends of the central part of the ferrite cups. The transformer can also be made on the basis of a ferrite (of the same brand) armored magnetic core B22. In this case, PEV-2-0.09 wire is used, and the number of turns of windings 1.1 and 1.2 is increased to 230. The KT859A transistor can be replaced with KT826A, KT838A, KT846A.

Setting up the device is not difficult. By setting the slider of the trimming resistor R15 to the upper (according to the diagram) position, turn on the converter to the network and set the required output voltage values ​​with this resistor. To reduce interference in secondary circuits with a conversion frequency (20 kHz), it is necessary to experimentally select the connection point of the electrostatic screens with one of the wires of the primary circuit, as well as the connection point of the capacitor C8. To do this, it is enough to connect one of the terminals of any secondary winding through an alternating current milliammeter to the primary circuit and determine the named points based on the minimum readings of the device.

A converter assembled according to the described circuit was tested to power a load consuming 10 W of power. In this version, the number of turns of windings 1.1 and 1.2 was reduced to 120 (with magnetic core B30), capacitors SZ, C4 were replaced with one oxide capacitance of 10 μF (rated voltage 450 V), the resistance of resistor R10 was reduced to 2.7 Ohms, and resistor R18 - up to 330 Ohm.

During engine operation, undesirable phenomena often arise, which are called “higher harmonics”. They negatively affect cable lines and power supply equipment and lead to unstable operation of the equipment. This results in inefficient use of energy, rapid aging of insulation, and reduced transmission and generation processes.

To solve this problem, it is necessary to comply with electromagnetic compatibility (EMC) requirements, the implementation of which will ensure the resistance of technical equipment to negative influences. The article makes a short excursion into the field of electrical engineering related to filtering the input and output signals of a frequency converter (FC) and improving the performance characteristics of motors.

What is electromagnetic noise?

They arise from literally all metal antennas that collect and radiate disorienting energy waves. And cell phones, naturally, also induce magnetoelectric waves, so when the plane takes off/landing, flight attendants are asked to turn off the equipment.

Noises are divided according to the type of source of their origin, spectrum and characteristic features. Due to the presence of switching connections, electric and magnetic fields from different sources create unnecessary potential differences in the cable line, which build up on useful waves.

The interference that occurs in wires is called antiphase or common mode. The latter (they are also called asymmetrical, longitudinal) are formed between the cable and the ground, and affect the insulating properties of the cable.

The most common sources of noise are inductive equipment (containing coils), such as induction motors (IM), relays, generators, etc. Noise can “conflict” with some devices, inducing electric currents in their circuits, causing operational failures. process.

How is noise related to the frequency converter?

Converters for asynchronous motors with dynamically changing operating conditions, while having many positive features, have a number of disadvantages - their use leads to intense electromagnetic interference and interference that is formed in devices connected to them via a network or located nearby and exposed to radiation. Often the IM is placed remotely from the inverter and connected to it with an extended wire, which creates threatening conditions for the electric motor to fail.

Surely someone has had to deal with impulses from the electric motor encoder on the controller or with an error when using long wires - all these problems are, one way or another, related to the compatibility of electronic equipment.

Frequency converter filters

To improve the quality of control and weaken the negative influence, a filter device is used, which is an element with a nonlinear function. The frequency range beyond which the response begins to weaken is set. From an electronics perspective, this term is used quite often in signal processing. It defines the restrictive conditions for current pulses. The main function of the frequency generator is to generate useful oscillations and reduce unwanted oscillations to the level specified in the relevant standards.

There are two types of devices depending on their location in the circuit, called input and output. "Input" and "output" means that the filter devices are connected to the input and output side of the converter. The difference between them is determined by their application.

Inputs are used to reduce noise in the cable power supply line. They also affect devices connected to the same network. The outputs are intended for noise suppression for devices located near the inverter and using the same ground.

Purpose of filters for a frequency converter

During the operation of a frequency converter - an asynchronous motor, unwanted higher harmonics are created, which, together with the inductance of the wires, lead to a weakening of the noise immunity of the system. Due to the generation of radiation, electronic equipment begins to malfunction. Actively functioning ones ensure electromagnetic compatibility. Some equipment is subject to increased requirements for noise immunity.

3-phase filters for frequency generators allow you to minimize the degree of conducted interference in a wide frequency range. As a result, the electric drive fits well into a single network where several equipment are involved. EMC filters should be placed at a fairly close distance to the power inputs/outputs of the frequency converter, due to the dependence of the level of interference on the length and method of laying the power cable. In some cases they are installed.

Filters are needed for:

• noise immunity;
• smoothing the amplitude spectrum to obtain a pure electric current;
• selection of frequency ranges and data recovery.

All models of vector frequency converters are equipped with network filtering. The presence of filter devices provides the necessary level of EMC for system operation. The built-in device allows for minimal interference and noise in electronic equipment, and therefore meets compatibility requirements.

The absence of a filtering function in a frequency converter often leads to cumulative heating of the supply transformer, pulse changes, and distortion of the shape of the supply curve, which causes equipment failure.

Devices absolutely necessary to ensure the stable operation of complex electronic equipment. A buffer is mounted between the frequency converter and the power supply network to protect the line from higher harmonics. It is able to restrain these wave oscillations, the frequency of which is greater than 550 Hz. When a powerful induction motor system stops, a voltage surge may occur. At this moment the protection is triggered.

It is recommended to install to suppress high-frequency harmonics and correct the system coefficient. The importance of the installation is to reduce losses in the stators of the electric motor and unwanted heating of the unit.

Network chokes have advantages. Correctly selected device inductance allows you to ensure:

• protection of the frequency converter from voltage surges and phase asymmetry;
• the rate of growth of the short-circuit current decreases;
• the lifespan of capacitors increases.

You can think of a capacitor as a blocker. Therefore, depending on the method of connecting the capacitor, it can act as:

• low-frequency, if you connect it in parallel to the source;
• high frequency if connected in series with the source.

In practical circuits, a resistor may be required to limit the electron flow and achieve proper frequency cutoff.

2. Electromagnetic radiation (EMR) filters

Do you use a tea strainer when making tea? It is used to prevent “unwanted!” elements from logging into your system. There are many such unwanted phenomena in electrical circuits that occur at different frequencies.

An electric drive consisting of a frequency converter and an electric motor is considered a variable load. These devices and the inductance of the wires cause the generation of high-frequency voltage fluctuations and, as a result, electromagnetic radiation from the cables, which negatively affects the functioning of other devices.

This is an inductor with two (or more) windings in which current flows in opposite directions. The use of this device, consisting of an inductor and a capacitor, has several advantages. It is more reliable and can be used at the lowest operating temperatures. All this allows you to increase the service life of the electric motor. Low inductance and small size are also its key features.

Apply in cases where:

• Cables up to 15 m long are stretched from the frequency converter to the electric motor;
• there is a possibility of damage to the insulation of the motor windings due to pulsating voltage surges;
• old units are used;
• in systems with frequent braking;
• aggressiveness of the environment.

At fairly high frequencies the voltage drop is virtually zero and the capacitor behaves like an open circuit. The filter press is made in the form of a voltage divider with a resistor and capacitor. It is essentially used to reduce bandwidth, instability and correct the slew rate of Uout.

In simple terms, normal choke comes from the word “choke.” And it is still used today because it quite accurately describes its purpose. Think of how a "fist" tightens around a wire to prevent sudden changes in current.

4. Sine filters

Alternating current is a wave, some combination of sine and cosine. Different sine waves have different frequencies. If you know which frequencies are present, which need to be transmitted or removed, then the result can be a combination of “useful” waves, that is, without noise. This helps clean up the current signal to some extent. A sine wave filter is a combination of capacitive and inductive elements.

One of the measures to ensure electromagnetic compatibility is the use of a sinusoidal apparatus; this may be necessary:

• with a group drive with one converter;
• when operating with a minimum of switching connections with cables (without a shield) of the electric motor (for example, connection via a daisy-chain method or an overhead power supply);
• to reduce losses on long cables.

The purpose of the device is to prevent damage to the insulators of the electric motor winding. Due to the almost complete absorption of high pulses, the output voltage takes on a sinus form. Its correct installation is an important aspect to reduce network interference and therefore emissions. This allows the use of long wires and helps reduce noise levels. Low inductance also means smaller size and lower price. The devices are designed using the dU/dt filtration method with a larger difference in the value of the elements.

5. High-frequency common mode filters

If a distorted voltage sine wave behaves as a series of harmonic signals added to the fundamental frequency, then the filter circuit allows only the fundamental frequency to pass, blocking unnecessary higher harmonics. The input filtering device is designed to suppress high-frequency noise.

The devices differ from those discussed above in a more complex design. The most important way to reduce noise is to comply with the required grounding regulations in the electrical cabinet.

How to Select the Correct Input and Output EMC Filter

Their distinctive advantages lie in their high noise absorption coefficient. EMC is used in devices with switching power supplies. It is worth adhering to the requirements of the instructions for the specific control circuit of asynchronous motors. There are general principles that determine the correct choice.

Please note that the selected model must comply with:

• parameters of the frequency converter and power supply network;
• the level of interference reduction to the required limits;
• frequency parameters of electrical circuits and installations;
• features of the operation of electrical equipment;
• possibilities for electrical installation of the model into the control system, etc.

The easiest way to improve the quality of your electrical network is to take action at the design stage. The most interesting thing is that in the event of an unreasonable deviation from design decisions, the blame falls entirely on the shoulders of the electricians.

The correct decision on the choice of the type of frequency converter, in combination with suitable filter equipment, prevents the occurrence of most problems for the operation of the power drive.

Ensuring good compatibility is achieved by correctly selecting the parameters of the components. Incorrect use of devices may increase the level of interference. In reality, input and output filters sometimes negatively affect each other. This is especially true when the input device is built into the frequency converter. The selection of a filter device for a specific converter is carried out according to technical parameters and, better, on the competent recommendation of a specialist. Professional consultation may bring you significant benefits, since expensive equipment is in fact always matched with a high-quality, inexpensive analogue. Or it does not operate in the required frequency range.

Conclusion

Electromagnetic interference affects equipment mainly at high frequencies. This means that correct operation of the system will only be achieved if the electrical installation and manufacturing specifications are followed, as well as the requirements for high-frequency equipment (eg shielding, grounding, filtering).

It is worth noting that measures to increase noise immunity are a set of measures. Using filters alone will not solve the problem. However, this is the most effective way to remove or significantly reduce harmful interference to the normal electromagnetic compatibility of electronic equipment. We must also not forget that whether or not a particular model is suitable for solving a problem is determined “on the spot” or through experiment and testing.

Power supply systems with the simultaneous use of traditional current supply and electricity from the sun are an economically sound solution for private households, cottage and holiday villages and industrial premises.

An indispensable element of the complex is a hybrid inverter for solar panels, which determines the voltage supply modes, ensuring the uninterrupted and efficient operation of the solar system.

For the system to work effectively, you need not only to choose the optimal model, but also to connect it correctly. And we will look at how to do this in our article. We will also consider existing types of converters and the best offers on the market today.

Using renewable solar energy in combination with centralized power supply provides a number of advantages. The normal functioning of the solar system is ensured by the coordinated operation of its main models: solar panels, battery, and one of the key elements - the inverter.

Solar system inverter is a device for converting direct current (DC) coming from photovoltaic panels into alternating electricity. It is on a current of 220 V that household appliances operate. Without an inverter, energy production is meaningless.

System operation diagram: 1 – solar modules, 2 – charge controller, 3 – battery, 4 – voltage converter (inverter) with alternating current (AC) supply

It is better to evaluate the capabilities of a hybrid model in comparison with the operating features of its closest competitors - autonomous and networked “converters”.

Network type converter

The device operates on the load of the general electrical network. The output from the converter is connected to electricity consumers, the AC network.

The scheme is simple, but has several limitations:

• operability when AC power is available in the network;
• The mains voltage must be relatively stable and within the operating range of the converter.

This variety is in demand in private homes with a current “green” tariff for electrification.

Solar Inverter Selection Parameters

The efficiency of the converter and the entire power supply system largely depends on the correct choice of equipment parameters.

In addition to the characteristics described above, you should evaluate:

• output power;
• type of protection;
• operating temperature;
• installation dimensions;
• availability of additional functions.

Criterion #1 – device power

The rating of the solar inverter is selected based on the maximum load on the network and the expected battery life. In start-up mode, the converter is capable of delivering a short-term increase in power at the time of commissioning capacitive loads.

This period is typical when turning on dishwashers, washing machines or refrigerators.

When using lighting lamps and a TV, a low-power inverter of 500-1000 W is suitable. As a rule, it is necessary to calculate the total power of the equipment being used. The required value is indicated directly on the device body or in the accompanying document.

Overview of the capabilities, operating modes and efficiency of using the 3 kW InfiniSolar multifunction converter:

Designing a solar power supply system is a complex and responsible task. It is best to entrust the calculation of the necessary parameters, selection of solar complex components, connection and commissioning to professionals.

Mistakes made can lead to system failures and ineffective use of expensive equipment.

Are you choosing the best converter option for operating an autonomous solar energy supply system? Do you have questions that we did not cover in this article? Ask them in the comments below - we will try to help you.

Or maybe you noticed inaccuracies or inconsistencies in the material presented? Or do you want to supplement the theory with practical recommendations based on personal experience? Write to us about this, share your opinion.