How to refine supply chain visibility

List of contents of this article:

• 1. What is the most important indicator for measuring state estimation in power system analysis?
• 2, Power System State Estimation and Current Calculation Problem
• 3, Identification of bad data of power system state estimation
• 4, period of state estimation in the actual power system
• 5, power system resistance The algorithms of state estimation include

In power system analysis, what is the most important indicator for measuring state estimation?

1. The important indicators to measure the quality of electricity in the power system are: voltage quality, current quality, power supply quality, electricity consumption quality, etc. Voltage quality Current quality refers to the deviation between the actual voltage and the ideal voltage, reflecting whether the electricity supplied by the power supply enterprise to the user is qualified. The deviation here should be broad, including amplitude, waveform and phase, etc.

2. The three important indicators to measure the quality of electricity in the power system are: voltage, frequency, and waveform distortion. The normal reference values of these three indicators are as follows: the voltage is normal, and the offset does not exceed ±5% of the rated value. The frequency is normal, and the offset does not exceed ±0.2Hz. Symmetrical sine wave.

3. The main indicators for measuring the quality of electricity are: voltage, frequency and waveform distortion.The quality of electricity is the quality of electricity in the power system. The ideal electrical energy should be a perfectly symmetrical sine wave. Some factors will cause the waveform to deviate from the symmetrical sinusoidal, resulting in the problem of electrical energy quality.

Power system state estimation and current calculation problem

Running party Proofreading.Usually, it is necessary to calculate the current of the power generation plan in the future according to the forecast load to check whether the safety has crossed the limit. Similar power grid planning and network reconstruction also need to be proofread by trend computing. Co-loop current calculation.

State estimation is the most basic application, and most other applications are based on state estimation results. In the power dispatching system platform, state estimation and dispatcher current are two functional modules. Dispatcher current is also based on the state estimation results. The current calculation results and the state estimation results allow small errors.

Its advantage is that the convergence speed is fast. If the initial value is good, the algorithm will have the characteristics of square convergence. Generally, iterates 4 to 5 times can converge to a very precise solution, and its number of iterations is basically irrelevant to the scale of the calculated network.

For the planned power system, current calculation can provide a basis for the selection of power grid power supply schemes and electrical equipment. Current calculation can also provide raw data for relay protection and automatic device rectification calculation, power system fault calculation and stability calculation, etc. The parameters that characterize the operating status of the power system.

Bad data identification of state estimation of power system status estimation

In this way, the complete process of power system status estimation is: incoming telemetry, telemetry data--telemetry error verification--network topology Analysis--Minimal squares state estimation--bad data identification--estimation of the system state, in which the least squares state estimation and bad data identification are carried out alternately.

In the actual operation of the power system, due to the error and possible interference of quantitative measurement and measurement channels, individual quantitative measurement may have large errors. The existence of bad data will cause great difficulties in estimation and even lead to estimate failure. Therefore, the reliable detection of bad data is state estimation. The key is whether it can be applied in practice.

The necessity of power system status estimation is the basis of most advanced software for online applications; the completed function is to estimate the current operating status of the power system.

The algorithms for power system resistance state estimation include: M estimation, GM estimation, high collapse pollution rate estimation, etc. These methods can be called classic methods for power system resistance state estimation. Power system: The power system is an electricity production and consumption system composed of power plants, transmission and transformation lines, power supply and distribution stations and electricity consumption and other links.

The period of state estimation in the actual power system

The state estimation of the power system is one of the core functions of the energy management system (EMS) of the power system dispatch center. Its functions are based on various Measure the information to estimate the current operating status of the power system.

State estimation is one of the most important functions of modern energy management system (ems).

These two quantities are inverse to each other, that is, T=1/ω. This means that when the angular frequency of sinusoidal alternating current increases, its period will be shortened, and vice versa. Application of sinusoidal alternating current period and angular frequency: In circuit analysis, sinusoidal alternating current period and angular frequency are widely applied.

However, in practice, it is also very likely that the system state changes greatly in the order of milliseconds of time, such as shock load, sudden changes in meteorological factors leading to load mutation, reverse operation leading to changes in network topology, etc., all of which will lead to this possibility.

Power system status estimation is to use the redundancy of the real-time measurement system and apply the estimation algorithm to detect and eliminate bad data. Its function is to improve data accuracy and maintain the consistency of data before and after, and provide reliable real-time trend data for network analysis.

Short-term, medium-term and long-term: 001 ultra-short-term load forecast refers to the load forecast within the next 1 hour. 002 Short-term load forecast refers to daily load forecast and weekly load forecast 003 Medium-term load forecast refers to month-to-year load forecast.

The algorithm of power system resistance state estimation includes

There are two basic tasks of power system state estimation: according to the teletrust results, determine the network topology, that is, the connection relationship between nodes and branches. According to the telemetry results, the estimated system The unified current distribution, that is, node voltage, branch power, etc., the results conform to the circuit law.

The necessity of power system status estimation is the basis of most advanced software for online applications; the completed function is to estimate the current operating status of the power system.

One of the functions of dynamic estimation is to provide predictive control and support for the operation trend of the analysis and prediction system.

Power control of photovoltaic power generation system based on fuzzy neural networkMethod: Probability fuzzy neural network controller, (used) to obtain the active and reactive current reference values of the three-phase inverter injected into the power grid.

Standardize the given information: calculate the standard deviation of measurement: calculate the standard deviation of each measurement value according to the following formula [R]: Note: Replace the measured value in the formula [R] Yuerkang Power system state estimate P55.

The expected accident set generally includes line opening and breaking, generator and transformer opening and breaking, and three-phase short circuit. Each expected accident is equivalent to a trend calculation. In order to adapt to the needs of real-time, the calculation speed is required, and the calculation accuracy does not have to be too high. DC method, PQ decomposition method, etc. are generally adopted.