Voltage drop calculation, please help!

Set, the rated current of the motor is about 200A, the operation is full load, the power factor is, the number of ampere kilometers is 200, check the table in the design manual, 150 square aluminum cable, the voltage loss per ampere kilometer is, so the total voltage loss is, it can be seen that such a large voltage loss is not good for normal operation, let alone moving. When it comes to starting, what method is used is also related to the capacity of the power supply transformer. I won't go into detail here.

If you look up the table according to the value of KWKM (which should be the power input to the motor, which is the rated power divided by the efficiency), the results are similar.

FYI. Above is 2009-6-12 11:52.

I tried to calculate the first (three-phase) formula and data according to zzshcn, and the result was, , the calculation was wrong.

Check the impedance, resistance:, reactance:, and reactance of the 1000v three-core aluminum core paper insulated 150mm2 cable in the design manual, and also calculate according to the formula, and the result is: ,.

In addition, Chen Jiandao's calculation of resistance is incorrect, and its "three-phase line voltage is: 380 29 2" is also incorrect, this is a single-phase calculation.

Thank you for your reference.

Voltage drop to <5% Yes!

See ** for detailed calculations!

The power of the motor is 110kw of rated current: i 220a, line length: l 700m, resistivity of aluminum core: wire cross-sectional area: s 150 square.

Find the line resistance (single wire): r (l s).

Find the voltage drop of a single line: u ri

The three-phase line voltage is: 380 29 2 322 (V).

Voltage drop calculation formula:△u=（p*l）/（a*s）

Voltage drop, also known as voltage or potential difference, is expressed as u, unit volts (V), and is a physical quantity that describes the ability of the electric field force to move a charge to do work。The reference direction of the voltage drop is indicated by a "+" polarity or a double subscript. The actual direction of the voltage is specified as the direction in which the electric field force moves the work done by the positive charge, from the high potential end ("+ polarity) to the low potential end ("-polarity), that is, the direction in which the potential decreases.

Voltage, also known as potential difference or potential difference, is a physical quantity that measures the difference in energy between a unit charge in an electrostatic field due to different potentials. Its magnitude is equal to the work done by a unit positive charge to move from point A to point B due to the action of an electric field force, and the direction of the voltage is specified as the direction from the high potential to the low potential. The SI unit system of voltage is volts (V, referred to as volts), and the commonly used units are millivolts (mV), microvolts (V), kilovolts (kv), etc.

This concept is similar to the water pressure caused by the water level. It should be pointed out that the term "voltage" is generally only used in electrical circuits, while "potential difference" and "potential difference" are generally applied to all electrical phenomena.

The voltage drop is calculated as u=(p*l) (a*s).

Wherein: p is the line load; l is the length of the line; a is the conductor material coefficient (about 77 for copper and 46 for aluminum); s is the cable cross-section.

At temperature = 20C, the resistivity of copper is ohms*mm²; At a temperature = 75C, the resistivity of copper is ohm*mm² meters, and in general, the resistivity varies with temperature.

The resistance of the wire at a certain temperature = the length of the wire * the resistivity of the wire The carrying area of the wire is 150 meters and 16 square millimeters, and the resistance of the copper wire is at temperature = 20C = 150 * ohms).

If only two of them are used (one for the live wire and one for the ground wire), then the line resistance = ohms * 2 (string) = ohms for the load, 30 amperes for the line voltage drop = 30 * volts).

If two parallel lines are used as live wires and the other two are connected in parallel as ground wires, the line resistance is Europe and the United States, and the line voltage drop = 30 * volts), the specific line voltage drop in use changes with the ambient temperature and load change surface, the calculation method, the formula is like this.

The formula for calculating the voltage drop between two points is: u=w q.

where w – electric field force.

The work done by the moving charge, q – the positive charge moved by the electric field force.

The reference direction of the voltage drop is indicated by a "+" polarity or a double subscript. The actual direction of the voltage is specified as the direction in which the electric field force moves the work done by the positive charge, from the high potential end ("+ polarity) to the low potential end ("-polarity), that is, the direction in which the potential decreases.

The voltage drop can also be called the potential difference.

When the potential of a certain point is zero, the voltage of any point in the circuit to that reference point is the potential (u) of that point. The potential difference between two points is also the voltage drop between two points.

Voltage drop law:

The voltage is what pushes the free charge to move directionally to form an electric current. The reason why the current is able to flow in the wire is also because of the difference between high and low potential in the current. This difference is called the potential difference, also known as the voltage.

In other words. In a circuit, the potential difference between any two points is called the voltage at those two points. The letter u is usually used to represent voltage.

A power supply is a device that provides voltage or electrical energy to both ends of an electrical appliance. The magnitude of the voltage can be used with a voltmeter.

Symbol: v) Measurement.

Series circuits. Voltage law: The total voltage at both ends of the series circuit is equal to the sum of the voltages at both ends of each part of the circuit.

Formula: u=u1+u2.

Parallel circuits. Voltage law: The voltage at both ends of each branch of the parallel circuit is equal and equal to the power supply voltage.

Formula: u=u1+u2.

The voltage drop is calculated using the following formula: u=(p*l) (a*s). Voltage drop is also known as voltage orPotential difference, denoted as u, in volts (v), is the descriptionElectric field forceThe ability to move the charge to do workPhysical quantities

The reference direction of the voltage drop is indicated by a "+" polarity or a double subscript. The actual direction of the voltage is specified as the direction in which the electric field force moves the work done by the positive charge, from the high potential end ("+ polarity) to the low potential end ("-polarity), that is, the direction in which the potential decreases.

Scope of application: The current value of each branch in the circuit can be calculated accurately and quickly. Due to the quasi-steady current (low-frequency alternating current.

has electromagnetic waves.

The long run is larger than the scale of the circuit, so its current and voltage in the circuit at every moment can satisfy Kirchhoff's law to a good enough extent.

Therefore, the application of Kirchhoff's law can also be extended to AC circuits.

In addition to the analysis of DC circuits and quasi-stable circuits, it can also be used for the analysis of nonlinear circuits containing electronic components. When using Kirchhoff's law for circuit analysis, it is only about how the circuit is connected, not about the properties of the components that make up the circuit.