CN-121978431-A - Power transmission and distribution line ice melting characteristic simulation load system and operation method

CN121978431ACN 121978431 ACN121978431 ACN 121978431ACN-121978431-A

Abstract

The invention discloses an ice melting characteristic simulation load system of a power transmission and distribution line and an operation method thereof, wherein the ice melting characteristic simulation load system comprises an anode port and a cathode port, the anode port is connected with the anode of an ice melting device, the cathode port is connected with the cathode of the ice melting device, the anode port is connected with an anode bus, the cathode port is connected with a cathode bus, and a plurality of impedance units are arranged between the anode bus and the cathode bus; and adjusting the serial-parallel combination state of the plurality of impedance units according to the expected ice melting voltage input by the positive electrode port. The mode can achieve larger load current in a wider input voltage range, meets the load test requirements of high-voltage heavy current and low-voltage heavy current, and avoids the problem that the rated power of a conventional load is overlarge due to the fact that the high-voltage heavy current and the low-voltage heavy current are compatible.

Inventors

HUANG QINGJUN
ZHU SIGUO
ZHU YUAN
ZHU JUNWEI
SUN SHIYI
CHEN ZEHONG
CAI XIANG
ZENG LI
LI ZIANG

Assignees

国网湖南省电力有限公司防灾减灾中心
国网湖南省电力有限公司
国家电网有限公司

Dates

Publication Date: 20260505
Application Date: 20251225

Claims (10)

1. The ice melting characteristic simulation load system of the power transmission and distribution line is characterized by comprising an anode port and a cathode port, wherein the anode port is connected with the anode of an ice melting device, the cathode port is connected with the cathode of the ice melting device, the anode port is connected with an anode bus, the cathode port is connected with a cathode bus, and a plurality of impedance units are arranged between the anode bus and the cathode bus; according to the expected ice melting voltage input by the positive electrode port And adjusting the serial-parallel combination state of a plurality of the impedance units.
2. The power transmission and distribution line ice melting characteristic simulation load system according to claim 1, wherein each of the impedance units is arranged at intervals in sequence along the length direction of the negative bus bar.
3. The ice-melting characteristic simulation load system of a power transmission and distribution line according to claim 1, wherein each impedance unit comprises an electric breaking switch, a first movable connecting line, a resistor, a second movable connecting line, The upper end of the electric breaking switch in each impedance unit is connected with the positive bus, the upper end of the resistor in each impedance unit is fixedly connected with the lower end of the first movable connecting wire, and the lower end of the resistor in each impedance unit is fixedly connected with the upper end of the second movable connecting wire; The upper end of a first movable connecting wire in the current impedance unit is connected with the lower end of the electric breaking switch in the current impedance unit or the lower end of the resistor in the other impedance unit, and the lower end of a second movable connecting wire in the current impedance unit is connected with the upper end of the resistor in the other impedance unit or the negative bus.
4. A power transmission and distribution line ice melting characteristic simulation load system according to claim 3, wherein at least one of the electrical breaking switches in the plurality of impedance units is a semiconductor switch capable of being opened and closed at high frequency, and the semiconductor switch regulates and controls the average current of the impedance units in the branch circuit by controlling the duty ratio of the semiconductor switch; At least one of the electric breaking switches in each impedance unit is an air switch, and the air switch is used for obtaining basic current of graded switching.
5. The ice-melting characteristic simulation load system for a power transmission and distribution line according to claim 3, wherein, When the expected ice melting voltage When the rated voltage of the single impedance unit is not exceeded, a plurality of impedance units are connected in parallel, and the load current is regulated by regulating the switching state of an electric breaking switch in each impedance unit, wherein the two ends of a first movable connecting wire in each impedance unit are respectively connected with the electric breaking switch and a resistor in the impedance unit, and the two ends of a second movable connecting wire in each impedance unit are respectively connected with the resistor and a negative bus in the impedance unit; when the expected ice melting voltage When the rated voltage of the impedance unit is larger than that of a single impedance unit, the ice melting characteristic simulation load system of the power transmission and distribution line comprises n parallel branches, each branch comprises m impedance units which are connected in series, m and n are positive integers, Regulating the switching state of the electric breaking switch in the 1 st impedance unit in each branch, and regulating the quantity of the input branches and the load current; In each branch, the upper end of a first movable connecting wire in the 1 st impedance unit is connected with an electric breaking switch, the upper ends of first movable connecting wires in other impedance units are connected with the lower end of a resistor in the previous impedance unit, the lower end of a second movable connecting wire in the last 1 impedance unit is connected with a negative bus, and the lower ends of second movable connecting wires in other impedance units are connected with the upper end of a resistor in the next impedance unit.
6. The power transmission and distribution line ice-melting characteristic simulation load system according to claim 5, wherein the impedance value, rated current capacity and rated withstand voltage of the impedance unit in each branch are the same.
7. The power transmission and distribution line ice melting characteristic simulation load system according to claim 1, wherein the number of the impedance units is a first preset value.
8. The system according to claim 5, wherein the parameters and the number of each impedance unit are designed according to rated voltage and rated current full-load operation conditions of the load system, and the parameters of the impedance units include rated withstand voltage Rated current capacity Impedance value When the ice melting characteristic simulation load system of the power transmission and distribution line comprises n parallel branches, rated withstand voltage of each group of impedance units in each branch is calculated Rated current capacity Impedance value The setting is performed after calculation according to the following formula: Simulating rated current of a load system for the ice melting characteristic of the power transmission and distribution line, And simulating rated voltage of a load system for the ice melting characteristic of the power transmission and distribution line.
9. The power transmission and distribution line ice-melting characteristic simulation load system according to claim 8, wherein when the input expected ice-melting voltage is Or when the current is changed in a large range, checking that the ice melting characteristic simulation load system of the power transmission and distribution line is at the lowest input voltage The expected ice melting current is obtained The evaluation conditions are as follows: when the current of the impedance units in the current series-parallel mode does not meet the above formula, the number n of parallel groups of the branches or the series number m of the resistors in each branch should be adjusted, and the parameters of each impedance unit should be redesigned until the expected ice melting current The above conditions are satisfied.
10. A method of operating a power transmission and distribution line ice melting characteristic simulation load system employing the power transmission and distribution line ice melting characteristic simulation load system according to any one of claims 1 to 9, comprising: according to the expected ice-melting voltage before the load operates And the expected ice-melting current The size of each impedance unit is adjusted to the serial-parallel combination state, wherein, When the expected ice melting voltage When the rated voltage of the single impedance unit is not exceeded, directly connecting the impedance units in parallel; when the expected ice melting voltage When the rated voltage of the impedance unit is larger than the rated voltage of a single impedance unit, connecting resistors in m impedance units in series to form a branch, connecting n branches in parallel, wherein m and n are positive integers; according to the expected ice-melting voltage And the expected ice-melting current Determining the rated withstand voltage of each group of the impedance units in the branch Rated current capacity Impedance value ; Checking that the ice melting characteristic simulation load system of the power transmission and distribution line is at the lowest input voltage The expected ice melting current is obtained Rated current of load system simulated by ice melting characteristics of power transmission and distribution line And the size relation between the impedance units and the branches is used for determining the number of the branches which are put into use and the serial number of the impedance units in each branch according to the size relation.

Description

Power transmission and distribution line ice melting characteristic simulation load system and operation method Technical Field The invention relates to the technical field of deicing of electric lines, in particular to a simulated load system for deicing characteristics of a power transmission and distribution line and an operation method. Background The ice and snow disasters frequently occur in China, accidents such as line breakage and tower falling are often caused after ice is covered on power transmission and distribution lines, long-time power failure is caused, and safe operation and power supply reliability of a power grid are seriously threatened. In order to reduce accidents caused by ice and snow disasters, in the prior art, ice melting operation is carried out in time according to ice coating conditions. The ice melting device is used as emergency equipment and is generally used for a short time after severe ice coating of a rain and snow line in winter. In order to ensure that the distribution network ice melting device can normally operate when ice is required to be covered, the ice melting function detection test of the ice melting device needs to be carried out regularly in the process of designing and developing the ice melting device, before a new product leaves a factory and before stock equipment enters winter each year, and particularly, the belt running test under the ice melting working conditions of various lines with different lengths and different types is carried out. When the load characteristic test is carried out on the power transmission and distribution ice melting device, the full-load rated operation characteristic is required to be detected, and the load characteristic under different load working conditions is required to be checked, so that the function and the operation capacity of the ice melting device are comprehensively detected. For power transmission and distribution lines with different lengths and types, the ice melting current is mainly independent of the line length depending on the specification and the type of the wire, namely, the ice melting current with the same specification of the wire is basically determined, and the experimental load is required to output larger load current under different running voltages, particularly, larger current under lower voltage, so that the voltage and current regulation capability of the ice melting device is tested. However, in the existing load assessment test method for the ice melting device, rated voltage and current parameters of a load system are mainly configured according to the highest test voltage and the highest test current, the load only obtains rated current under the rated output voltage, but when the input voltage is lower than the rated voltage, only small-amplitude load current far lower than the rated current can be obtained, and assessment tests under the working condition that the ice melting line is shorter and corresponds to the ice melting voltage is lower are difficult to complete. Therefore, how to obtain a large current load under the condition that the input voltage is widely changed and flexibly adjust the current according to the needs so as to simulate the load characteristics of the ice melting device when melting ice in different lines becomes a technical problem to be solved urgently by the technicians in the field. Disclosure of Invention In order to solve the technical problems, the invention provides an ice melting characteristic simulation load system of a power transmission and distribution line and an operation method thereof, which are used for simulating the load characteristics of different types and lengths of power transmission and distribution lines in ice melting, so as to test the belt operation characteristics of the ice melting device in ice melting of different lines. The invention provides an ice melting characteristic simulation load system of a power transmission and distribution line, which comprises an anode port and a cathode port, wherein the anode port is connected with the anode of an ice melting device, the cathode port is connected with the cathode of the ice melting device, the anode port is connected with an anode bus, the cathode port is connected with a cathode bus, and a plurality of impedance units are arranged between the anode bus and the cathode bus; according to the expected ice melting voltage input by the positive electrode port And adjusting the serial-parallel combination state of a plurality of the impedance units. Optionally, each impedance unit is sequentially arranged at intervals along the length direction of the negative electrode bus. Optionally, each impedance unit comprises an electric breaking switch, a first movable connecting wire, a resistor and a second movable connecting wire, The upper end of the electric breaking switch in each impedance unit is connected with the positive bus, the upper end of the resistor in each impedance un