Concepts of active, apparent and reactive power. Understanding the concepts of active and reactive load

Reactive power is a quantity that characterizes the loads created by various oscillations of electromagnetic fields that occur in circuits with capacitors and inductors. And at its core, this is energy that passes from the power source to the consumer (load), and then returns back to these reactive components during one half-cycle.

There are consumers of electrical energy that create a purely active load. These include various heating elements, heating elements, incandescent lamps, etc. These consumers are not capable of generating significant electromagnetic fields. But other consumers are capable of generating reactive load. That is, create strong electromagnetic fields. The main representatives of this group can be considered devices that have capacitors and inductors in their supply circuits. As we already know, they have different effects on the amount of reactive power appearing in an electrical circuit.

So, if we apply current and voltage to the inductor with zero phase shift, then at the output of the circuit we will see a lag of the current from the voltage. But if we apply the same to the capacitor, then at the output we will get a leading voltage current. To understand the process, see the figure, which schematically shows the current leading the voltage with a capacitive load.

Such properties of reactive loads are used to regulate the voltage level in the network by compensating for large inductance with capacitive loads, and vice versa for large capacitances with inductance.

reactive power is calculated using the following formulas:

Where, x - , I And U- current and voltage flowing in the circuit, sinφ- reactive power factor

The SI unit of measurement of reactive power is the reactive volt ampere - VAR

The nature of losses in electrical circuits with reactive components can be seen from the graphs in the figures below:

In the absence of an active component in the load, the phase shift between current and voltage will be 90°. At the initial moment of time, when the voltage level is maximum, the current will tend to zero, therefore, the instantaneous power value UI will be zero at this time. During the first ¼ period, power can be visualized on a graph as the product UI(current and voltage), which will become zero at maximum current and zero value voltage.

In the next ¼ of the period, UI will lie in the negative coordinate region, therefore, the power will go back to the power source. The same thing will happen in the negative current half-cycle. As a result, the average (active) power consumption P avg for the period will be zero.

In this case, reactive power, in accordance with the formula above, tends to zero. The power consumption is equal to the product of current and voltage. The apparent power will be equal to the active power only. The power factor will be equal to unity ( P/S = 1).

Let's consider case of equality of reactive and active resistance in the load, i.e. a phase shift between current and voltage of 45°.

In this case: Q = U×I×sin45° = 0.71×U×I. Power factor = 0.71

As you probably noticed, reactive power usually has a negative effect, and therefore its compensation is necessary.

Unlike DC networks, where power has an expression and does not change over time, in networks alternating current this is wrong.

Power in an alternating current circuit is also variable. At any section of the circuit at any time t, it is defined as the product of the instantaneous values ​​of voltage and current.

Let's consider what active power represents

In a circuit with purely active resistance it is equal to:

If we accept and then it will come out:

Based on the expressions above, active energy consists of two parts - constant and variable, which changes with double frequency. Its average value

The difference between reactive power and active power

In a circuit where there is reactance (take inductive resistance as an example), the value of instantaneous power is equal to:

Accordingly as a result we get:

This expression shows that reactive energy contains only a variable part, which changes with double frequency, and its average value is zero

If the current and voltage have a sinusoidal shape and the network contains elements type R-L or R-C, then in such networks, in addition to energy conversion in the active element R, in addition, the energy of the electric and magnetic fields in the reactive elements L and C also changes.

In this case, the total power of the network will be equal to the sum:

What is apparent power using the example of a simple R-L circuit

Instantaneous change graphs values ​​u,i:

φ - phase shift between current and voltage

The equation for S will take the following form

Let's substitute and replace the amplitude values ​​with actual ones:

The value S is considered as the sum of two quantities, where

And - instantaneous active and reactive powers in sections R-L.

As we can see from the graph, the presence of an inductive component entailed the appearance of a negative part in the total power (shaded part of the graph), which reduces its average value. This occurs due to a phase shift; at some point in time, the current and voltage are in antiphase, so it appears negative meaning S.

Final expressions for effective values:

The active component of the network is expressed in watts (W), and the reactive component in reactive volt-amperes (var).

The total power of the network S is determined by the nominal data of the generator. For the generator it is determined by the expression:

For normal operation generator, the current in the windings and the voltage at the terminals should not exceed the rated values ​​of I n, U n. For the generator, the values ​​of P and S are the same, but in practice it was agreed to express S in volt-amperes (VA).

Also, the network energy can be expressed through each component separately:

Where S, P, Q are the active, reactive and impedance of the network, respectively. They form a power triangle:

If we recall the Pythagorean theorem, then from right triangle you can get the following expression:

The reactive component in the triangle is positive (Q L) when the current lags behind the voltage, and negative (Q C) when it leads:

For the reactive component of the network, the algebraic expression is valid:

From which it follows that inductive and capacitive energy are interchangeable. That is, if you want to reduce the influence of the inductive part of the circuit, you need to add capacitance, and vice versa. Below is an example of this diagram:

The phasor diagram shows the effect of the capacitor on cosφ. As you can see, when the capacitor is turned on, cosφ 2 > cosφ 1 and I l
Vector diagram

The relationship between total and reactive energy is expressed:

сosφ is the power factor. it shows what proportion of the total energy is active energy. The closer it is to 1, the more useful energy is consumed from the network.

Conclusions about the three components of an alternating current circuit

Unlike direct current circuits, alternating voltage circuits have three types of power - active, reactive, apparent. Active energy, as in direct current circuits, performs useful work. Reactive - does not do anything useful, but only reduces the efficiency of the network, heats the wires, and loads the generator. Total is the sum of active and reactive, it is equal to the power of the network. The inductive component of reactive energy can be compensated by the capacitive one. In practice, in industry this is implemented in the form.

and is the sum of two quantities, one of which is constant in time, and the other pulsates with double frequency.

Average value p(t) for period T is called active power and is completely determined by the first term of equation (5.1):

Active power characterizes the energy consumed irreversibly by the source per unit of time for production useful work consumer. The active energy consumed by electrical receivers is converted into other types of energy: mechanical, thermal, compressed air and gas energy, etc.

The average value of the second term of instantaneous power (1.1) (pulsates with double frequency) over time T is equal to zero, i.e., its creation does not require any material costs and therefore it cannot perform useful work. However, its presence indicates that a reversible process of energy exchange occurs between the source and the receiver. This is possible if there are elements capable of accumulating and releasing electromagnetic energy - capacitance and inductance. This component characterizes reactive power.

Full power at the receiver terminals in complex form can be represented as follows:

The unit of apparent power is S = UI - VA.

Reactive power- a quantity characterizing the loads created in electrical devices by vibrations (exchange) of energy between the source and the receiver. For a sinusoidal current, it is equal to the product of the effective current values I and voltage U by the sine of the phase shift angle between them: Q = UI sinφ. Unit of measurement - VAR.

Reactive power is not related to the useful operation of the electric motor and is spent only on the creation of alternating electromagnetic fields in electric motors, transformers, devices, lines, etc.

For reactive power, such concepts as generation, consumption, transmission, losses, balance are accepted. It is believed that if the current lags in phase with the voltage (inductive nature of the load), then reactive power is consumed and has a positive sign, and if the current leads the voltage (capacitive nature of the load), then reactive power is generated and has a negative value.

The main consumers of reactive power at industrial enterprises are asynchronous motors (60-65% of total consumption), transformers (20-25%), valve converters, reactors, overhead electrical networks and other receivers (10%).

The transfer of reactive power loads electrical networks and the equipment installed in them, reducing their capacity. Reactive power is generated by synchronous generators of power plants, synchronous compensators, synchronous motors (excitation current regulation), capacitor banks (BC) and power lines.

The reactive power generated by the network capacity has the following order of magnitude: a 20 kV overhead line generates 1 kVAr per 1 km of a three-phase line; underground cable 20 kV - 20 kVAr/km; overhead line 220 kV - 150 kVAr/km; underground cable 220 kV - 3 MVAr/km.

Power factor and reactive power factor.

The vector representation of quantities characterizing the state of the network leads to the representation of reactive power Q vector perpendicular to the active power vector R(Fig. 5.2). Their vector sum gives the total power S.

Rice. 5.1. Capacity Triangle

According to Fig. 5.1 and (5.2) it follows that S 2 = P 2 + Q 2 ; tgφ = Q/P; cosφ = P/S.

The main standard indicator characterizing reactive power was previously the power factor cosφ. At the inputs supplying an industrial enterprise, the weighted average value of this coefficient should have been in the range of 0.92-0.95. However, the choice of ratio P/S as a normative one, it does not give a clear idea of ​​the dynamics of changes in the real value of reactive power. For example, when the power factor changes from 0.95 to 0.94, the reactive power changes by 10%, and when the same factor changes from 0.99 to 0.98, the increase in reactive power is already 42%. When making calculations, it is more convenient to operate with the relation tgφ = Q/P, which is called the reactive power factor.

Enterprises with connected power of more than 150 kW (with the exception of “domestic” consumers) are defined reactive power factor limit values consumed during hours of heavy daily load of the electrical network - from 7 to 23 hours (Order of the Ministry of Industry and Energy of the Russian Federation dated February 22, 2007 No. 49 “On the procedure for calculating the ratio of active and reactive power consumption for individual power receiving devices of electrical energy consumers used to determine the obligations of the parties in contracts for the provision of services for the transmission of electrical energy ").

Limit values ​​of reactive power factors (tgφ) are normalized depending on the position of the point (voltage) of connection of the consumer to the network. For a network voltage of 100 kV tgφ = 0.5; for networks 35, 20, 6 kV - tgφ = 0.4 and for networks 0.4 kV - tgφ = 0.35.

The introduction of new policy documents on reactive power compensation was aimed at increasing the efficiency of the entire power supply system from power system generators to power receivers.

With the introduction of the reactive power factor, it became possible to represent active power losses in terms of active or reactive power: R= (P 2 /U 2) R(l + tan 2 φ).

Angle between power vectors R And S corresponds to the angle φ between the vectors of the active component of the current I a and total current I, which, in turn, is the vector sum of the active current I a, in phase with voltage, and reactive current I r, located at an angle of 90° to it. This arrangement of currents is a calculation technique associated with the decomposition into active and reactive power, which can be considered natural.

Most consumers require reactive power because they operate due to changes in the magnetic field. For the most commonly used engines in normal operation, the following approximate values ​​of tgφ can be given.

At the moment of starting the engines, a significant amount of reactive power is required, with tgφ = 4-5 (cosφ = 0.2-0.24).

Synchronous machines have the ability to consume or produce reactive power depending on the degree of excitation.

In synchronous generators and motors, the size of the excitation circuits limits the possibility of supplying reactive power to maximum values ​​of tgφ = 0.75 (cosφ = 0.8) or up to tgφ = 0.5 (cosφ = 0.9) (Table 5.1).

Synchronous motors produced by the domestic industry are designed for a leading power factor (cosφ = 0.9) and at a rated active load P nom and voltage U nom can generate rated reactive power Q nom ≈ 0.5 P nom.

When the SD is underloaded in terms of active power β = P/P nom< 1 возможна перегрузка по реактивной мощности α = Q/Q nom > 1.

The advantage of SD used for reactive power compensation compared to KB is the ability to smoothly regulate the generated reactive power. The disadvantage is that the active losses for generating reactive power for SD are greater than for KB.

Additional active losses in the LED winding caused by the generated reactive power within the range of cosφ variation from 1 to 0.9 with a rated active power of the LED equal to P nom, kW:

R nom = Q 2 nom R /U 2 nom,

Where Q nom - rated reactive power of SD, kV Ar; R- resistance of one phase of the LED winding in a heated state, Ohm; U nom - rated network voltage, kV.

In power supply systems industrial enterprises KBs compensate for the reactive power of the base (main) part of the load schedules, and SDs reduce the load peaks of the schedule.

Table 5.1

Dependences of the overload factor on reactive power of synchronous motors th

Synchronous compensators.

A type of SD is synchronous compensators (SC), which are SD without load on the shaft. Currently, SCs with a capacity above 5000 kV?Ar are produced. They have limited use in industrial networks. To improve the voltage quality indicators of powerful electric generators with sharply variable, shock loads (arc furnaces, rolling mills, etc.), SCs are used.

Static thyristor compensating devices.

In networks with sharply variable shock loads at a voltage of 6-10 kV, it is recommended to use not capacitor banks, but special high-speed reactive power sources (RPS), which should be installed near such electric power plants. The IRM diagram is shown in Fig. 5.2. It uses inductors as adjustable inductance LR and unregulated containers WITH 1-WITH 3.

Rice. 5.2. Fast acting reactive power sources

Inductance regulation is carried out by thyristor groups VS, the control electrodes of which are connected to the control circuit. The advantages of static IRM are the absence of rotating parts, the relative smoothness of regulation of reactive power supplied to the network, the possibility of three- and four-fold overload of reactive power. The disadvantages include the appearance of higher harmonics, which can arise during deep regulation of reactive power.

Due to additional power losses in the network caused by the consumption of reactive power, the total electricity consumption increases. Therefore, reducing reactive power flows is one of the main operational tasks electrical networks.

Reactive power is the part of electrical energy returned by the load to the source. The phenomenon of a situation occurring is considered harmful.

Occurrence of reactive power

Let's say the circuit contains a DC power supply and an ideal inductance. Turning on the circuit generates a transient process. The voltage tends to reach the nominal value; the growth is actively hampered by the inductance’s own flux linkage. Each turn of the wire is bent in a circular path. The resulting magnetic field will cross the adjacent segment. If the turns are located one after the other, the nature of the interaction will increase. This is called intrinsic flux linkage.

The nature of the process is as follows: the induced EMF prevents changes in the field. The current tries to grow rapidly, the flux linkage pulls back. Instead of a step we see a smoothed protrusion. Energy magnetic field spent to hinder the process that created it. The case of reactive power occurrence. The phase differs from the beneficial one and is harmful. Ideal: the direction of the vector is perpendicular to the active component. It is assumed that the wire resistance is zero (a fantastic scenario).

When the circuit is turned off, the process will be repeated in reverse order. The current tends to instantly drop to zero; energy is stored in the magnetic field. If the inductance disappears, the transition will take place suddenly, flux linkage gives the process a different coloring:

1. A decrease in current causes a decrease in the magnetic field strength.
2. The effect produced induces the back-EMF of the turns.
3. As a result, after the power source is turned off, the current continues to exist, gradually attenuating.

Graphs of voltage, current, power

Reactive power is a certain link of inertia, constantly lagging and interfering. The first question is: why then are inductors needed? Oh they have enough useful qualities. Benefit makes you put up with reactive power. A common positive effect is the operation of electric motors. Energy transfer occurs through magnetic flux. Between the turns of one coil, as shown above. A permanent magnet, a choke, and everything capable of being captured by an induction vector are subject to interaction.

The cases cannot be called comprehensive in a descriptive sense. Sometimes clutch flow is used in the form shown as an example. The principle is used by ballasts of gas-discharge lamps. The inductor is equipped with a myriad of turns: turning off the voltage does not cause a smooth decrease in current, but a surge of large amplitude of the opposite polarity. The inductance is great: the response is truly amazing. Exceeds the original 230 volts by an order of magnitude. It is enough for a spark to appear and the light bulb to light up.

Reactive power and capacitors

Reactive power is stored by magnetic field energy by inductances. What about the capacitor? Acts as a source of the reactive component. Let us supplement the review with the theory of vector addition. The average reader will understand. Oscillatory processes are often used in the physics of electrical networks. The well-known 220 volts (now accepted 230) in a 50 Hz outlet. A sine wave whose amplitude is 315 volts. When analyzing circuits, it is convenient to represent them as a clockwise rotating vector.

Graphical circuit analysis

The calculation is simplified and the engineering representation of reactive power can be clarified. The current phase angle is considered equal to zero and is plotted to the right along the abscissa axis (see figure). The reactive energy of the inductance is in phase with the UL voltage and is 90 degrees ahead of the current. Ideal case. Practitioners have to take into account the winding resistance. Part of the power will be reactive in inductance (see figure). The angle between projections is important. The value is called power factor. What does this mean in practice? Before answering the question, let's consider the concept of a resistance triangle.

Resistance triangle and power factor

To make analysis easier electrical circuits, physicists suggest using a resistance triangle. The active part is deposited, like a current, to the right of the abscissa axis. We agreed to direct the inductance up and the capacitance down. When calculating the total resistance of the circuit, we subtract the values. A combined case has been excluded. There are two options available: positive or negative reactance.

To obtain capacitive/inductive reactance, the parameters of the circuit elements are multiplied by a coefficient denoted by the Greek letter “omega”. Circular frequency is the product of the network frequency and twice the number Pi (3.14). Let us point out one more note about finding reactances. If the inductance is simply multiplied by the specified coefficient, the reciprocal of the product is taken for the capacitances. It is clear from the figure, which shows the indicated relationships that help calculate voltages. After multiplication, we take the algebraic sum of inductive and capacitive reactances. The former are considered positive quantities, the latter – negative.

Formulas of reactive components

Two components of resistance - active and imaginary - are projections of the total resistance vector on the abscissa and ordinate axes. Angles are preserved when abstractions are transferred to powers. The active one is plotted along the abscissa axis, the reactive one along the ordinate axis. Capacitances and inductances are the fundamental cause of negative effects in the network. It was shown above: without reactive elements, it becomes impossible to build electrical devices.

The power factor is usually called the cosine of the angle between the total resistance vector and the horizontal axis. Such an important parameter is attributed to the fact that the useful part of the source energy is a share of total waste. The share is calculated by multiplying the total power by the coefficient. If the voltage and current vectors coincide, the cosine of the angle is equal to one. Power is lost by the load, dissipated by heat.

Believe what is said! The average power of a period when connected to a source of pure reactance is zero. Half the time the inductance receives energy, the other half it releases. The motor winding is indicated in the diagrams by adding an EMF source that describes the transfer of energy to the shaft.

Practical interpretation of power factor

Many people notice a discrepancy in the case of practical consideration of reactive power. To reduce the coefficient, it is recommended to include large capacitors in parallel with the motor windings. The inductive reactance balances the capacitive reactance, the current is again in phase with the voltage. It's difficult to understand for this reason:

1. Let's say the primary winding of a transformer is connected to an alternating voltage source.
2. Ideally, active resistance is zero. Power must be reactive. But this is bad: they tend to make the angle between voltage and current zero!

But! The oscillatory process is indifferent to the operation of motors and transformers. The theory of reactive power assumes that all energy oscillates. To the last drop. In a transformer or motor, an active “leakage” of energy occurs from the field to perform work and induce current in the secondary winding. Energy cannot circulate between source and consumer.

In a real chain, the process of coordinating individual sections makes it difficult. To be on the safe side, suppliers require that capacitors be installed in parallel with the motor winding so that the energy circulates in the local segment and does not escape outside, heating the connecting wires. It is important to avoid overcompensation. If the capacitors are too large, the battery will cause the power factor to increase.

As for the phase shift, it occurs on the secondary winding of the substation transformer. That's not the role. The engine is running, some of the energy is not converted into useful work and is reflected back. The result is a power factor. The participating component of inductance is a technological, structural defect. The part that is not useful. We will compensate by adding capacitor units.

The correct matching is checked based on the fact that there is no phase shift between the voltage and current of a running electric motor. Excess energy circulates between the excess inductance of the windings and the installed capacitor unit. The goal of the event was achieved - to avoid heating the conductors of the network supplying the device.

What do they offer under the guise of saving energy?

The network offers to buy energy saving devices. Reactive power compensators. It is important not to go too far. Let’s say that the compensator would look appropriate next to the included refrigerator compressor, the collector motor of a vacuum cleaner, burdening the apartment with measures when incandescent light bulbs are working is a dubious undertaking. Before installation, take the trouble to find out the phase shift between voltage and current, according to the information, correctly calculate the volume of the capacitor bank. Otherwise, attempts to save in this way will fail, unless by chance you manage to point your finger at the sky and hit the mark.

The second aspect of reactive power compensation is metering. Made for large enterprises where there are powerful motors that create large phase angles. Special meters are being introduced to account for reactive power, paid according to the tariff. To calculate the payment coefficient, an assessment of heat losses of wires, deterioration of the operating conditions of the cable network, and some other factors are used.

Prospects for further study of reactive energy as a phenomenon

Reactive power is a phenomenon of energy reflection. Ideal chains of phenomena are deprived. Reactive power is manifested by the released heat on active resistance cable lines, distorts the sinusoidal waveform. A separate topic of conversation. If there are deviations from the norm, the engines do not operate so smoothly and the transformers are hindered.

The main goal in electricity transmission is to increase the efficiency of networks. Therefore, it is necessary to reduce losses. The main cause of losses is reactive power, compensation of which significantly improves the quality of electricity.

Reactive power causes unnecessary heating of wires and overloads electrical substations. Transformer power and cable sections are forced to be overestimated, and the network voltage is reduced.

The concept of reactive power

To find out what reactive power is, it is necessary to determine other possible types of power. When there is an active load (resistor) in the circuit, only active power is consumed, which is completely spent on energy conversion. This means that we can formulate what active power is – that at which the current does effective work.

At direct current, only active power is consumed, calculated according to the formula:

Measured in watts (W).

In electrical circuits with alternating current in the presence of active and reactive loads, the power indicator is summed from two components: active and reactive power.

1. Capacitive (capacitors). Characterized by a phase advance of current compared to voltage;
2. Inductive (coils). Characterized by a phase lag of the current relative to the voltage.

If we consider a circuit with alternating current and a connected active load (heaters, kettles, filament light bulbs), the current and voltage will be in phase, and the total power taken at a certain time cutoff is calculated by multiplying the voltage and current readings.

However, when the circuit contains reactive components, the voltage and current readings will not be in phase, but will differ by a certain amount determined by the offset angle "φ". Taking advantage in simple language, it is said that a reactive load returns as much energy to the circuit as it consumes. As a result, it turns out that for active power consumption the indicator will be zero. At the same time, a reactive current flows through the circuit, which does not perform any effective work. Consequently, reactive power is consumed.

Reactive power is the portion of energy that allows the electromagnetic fields required by AC equipment to be established.

Reactive power is calculated using the formula:

Q = U x I x sin φ.

The unit of measurement for reactive power is VAR (volt-ampere reactive).

Expression for active power:

P = U x I x cos φ.

The relationship between active, reactive and apparent power for a sinusoidal current of variable values ​​is represented geometrically by the three sides of a right triangle, called the power triangle. AC electrical circuits consume two types of energy: active power and reactive power. In addition, active power is never negative, whereas reactive power can be either positive (with an inductive load) or negative (with a capacitive load).

Important! From the power triangle it is clear that it is always useful to reduce the reactive component in order to increase the efficiency of the system.

The total power is not found as algebraic sum active and reactive power values, this is the vector sum of P and Q. Its quantitative value is calculated by extracting square root from the sum of the squares of power indicators: active and reactive. Total power can be measured in VA (volt-ampere) or its derivatives: kVA, mVA.

In order to calculate the total power, it is necessary to know the phase difference between the sinusoidal values ​​of U and I.

Power factor

Using a geometrically represented vector picture, you can find the ratio of the sides of the triangle corresponding to the useful and total power, which will be equal to the cosine phi or power coefficient:

This coefficient determines the efficiency of the network.

The number of watts consumed is the same as the number of volts consumed at a power factor of 1 or 100%.

Important! The greater the cos φ, or the smaller the shift angle of the sinusoidal values ​​of current and voltage, the closer the total power is to the active value.

If, for example, there is a coil for which:

• P = 80 W;
• Q = 130 VAr;
• then S = 152.6 BA as root mean square;
• cos φ = P/S = 0.52 or 52%

We can say that the coil requires 130 VAr of total power to do 80 W of useful work.

Correction cos φ

To correct cos φ, the fact is used that with a capacitive and inductive load, the reactive energy vectors are in antiphase. Since most loads are inductive, by connecting a capacitor, you can increase cos φ.

Main consumers of reactive energy:

1. Transformers. They are windings that have inductive coupling and transform currents and voltages through magnetic fields. These devices are the main element of electrical networks that transmit electricity. Losses especially increase when operating at idle and at low load. Transformers are widely used in production and in everyday life;
2. Induction furnaces, in which metals are melted by creating eddy currents in them;
3. Asynchronous motors. The largest consumer of reactive energy. The torque in them is created by the alternating magnetic field of the stator;
4. Electrical power converters such as power rectifiers used for power contact network railway transport and others.

Capacitor banks are connected at electrical substations to control the voltage within specified levels. The load varies throughout the day with morning and evening peaks, as well as throughout the week, decreasing on weekends, which changes the voltage readings. By connecting and disconnecting capacitors its level is varied. This is done manually and using automation.

How and where cos φ is measured

Reactive power is checked by changing cos φ with a special device - a phase meter. Its scale is graduated in quantitative values ​​of cos φ from zero to one in the inductive and capacitive sectors. Fully compensate Negative influence inductance will not succeed, but it is possible to get closer to the desired value - 0.95 in the inductive zone.

Phase meters are used when working with installations that can affect the operating mode of the electrical network through regulation of cos φ.

1. Since financial calculations for consumed energy also take into account its reactive component, factories install automatic compensators on capacitors, the capacity of which can vary. Networks typically use static capacitors;
2. When regulating cos φ in synchronous generators by changing the exciting current, it is necessary to monitor it visually in manual operating modes;
3. Synchronous compensators, which are synchronous motors operating without load, supply energy to the network in overexcitation mode, which compensates for the inductive component. To regulate the exciting current, observe the readings of cos φ using a phase meter.

Power factor correction is one of the most effective investments for reducing energy costs. At the same time, the quality of the energy received improves.

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