39results about How to "Reduce load shedding" patented technology

The invention discloses a coordinated control method for improving the frequency stability of the power grid after DC blocking. The cooperative control master station receives the DC blocking information sent by the DC control execution station, and obtains the control amount and the effective control object set from the matching of the control strategy table; The control master station identifies the current effective control quantities of DC, energy storage, and load controllable objects, forms real-time control measures, and sends them to the DC control execution station, energy storage control execution station, and load control execution station to coordinate and complete emergency control. The invention provides a coordinated control method for improving the frequency stability of the power grid after DC blocking, which can be used to solve the priority order problem of various control objects after the DC blocking of the receiving power grid, and is beneficial to make full use of the available DC, energy storage, and load systems. control characteristics, improve the frequency stability of the system, avoid reducing load shedding, and improve the economy and safety of power system operation.

The invention provides a multi-scheme comprehensive evaluation method for the automatic low-frequency load reduction of a large electric network, which realizes that the design of a plurality of schemes of low-frequency load reduction, the comprehensive evaluation and comparison and the mass simulated checking and calculation of a recommended scheme are all finished automatically by a program, realizes an integrative procedure, changes a traditional calculation mode that engineering staff carries out manual calculation, and enhances the efficiency and the accuracy of the establishment of the automatic low-frequency load reduction schemes greatly. The method has rationality, applicability and generalizability.

The invention relates to a coagulation method of halogenated butyl rubber, which belongs to the technical field of butyl rubber synthesis. After the butyl rubber glue has undergone a halogenation reaction, and then undergoes a neutralization reaction, it enters the first coagulation kettle, and hot water is also passed into the first coagulation kettle, so that the first gas phase containing hexane is generated in the first coagulation kettle. The first gas phase is condensed by the condenser and then enters the hexane purification system for treatment; the colloidal water in the first coagulation tank is sent to the second coagulation tank through the first delivery pump, so that the second gas phase containing hexane is produced in the second coagulation tank, The second gas phase is extracted from the second condensation tank by the first water ring vacuum pump, condensed by the condenser, and then enters the hexane purification system for treatment. Using a mechanical heat pump to recycle the steam waste heat at the top of the first condensation tank will not only reduce the steam consumption in the production process of halogenated butyl, but also reduce the amount of circulating water used for condensing steam.

The invention relates to a power system intelligent low-frequency low-voltage load reduction method based on an intelligent household electrical appliance. The method comprises the following steps: when large disturbance in a system is monitored, determining whether the frequency and the voltages of the system are decreased to preset load reduction motion values, and once the frequency and the voltages reach the load reduction motion values, obtaining power shortage in the system and determining a load capacity which should be cut from the system; starting an intelligent household electrical appliance load reduction module; starting low-frequency low-voltage load reduction; and if intelligent household electrical appliance load reduction cannot enable the system frequency and voltages to restore to normal operation scopes and the frequency and voltages are continuously decreased to preset values of the low-frequency low-voltage load reduction, starting the low-frequency low-voltage load reduction, according to a residual load reduction amount, successively starting a basic round and a special round of low-frequency load reduction for cutting off loads until the frequency is restored to the normal operation scope, and embedding one low-voltage load reduction module in each round of low-frequency load cutting. According to the invention, after a power system is disturbed, the frequency and voltages can be effectively and rapidly inhibited from dropping and even collapsing, the load cutting amount is small, and the economic loss is small.

The present invention discloses a three-layer heat and power combined supply microgrid energy control method for reducing wind curtailment. According to the method, the economic operation of a microgrid is divided into three time scales, namely, a day-ahead dispatching layer, a short-term adjustment layer and a real-time control layer. In the day-ahead dispatching layer, a dispatching period is divided into a plurality of periods, and day-ahead dispatching is converted into a mixed integer linear optimization problem based on day-ahead prediction data. In the short-term adjustment layer, short-term adjustment is converted into a non-linear optimization problem according to the startup-shutdown plans of the day-ahead dispatching layer and short-term prediction data. In the real-time control layer, a local controller carries out local control through adopting a flexible droop control mode according to a received optimization result of the short-term adjustment layer and actually-measured data. The three-layer heat and power combined supply microgrid energy control method for reducing wind curtailment is applicable to the grid-connected economic operation of a heat and power combined supply microgrid comprising various controllable power sources, uncontrollable power sources, heat storage, energy storage batteries and controllable loads, and is especially suitable for a heat and power combined supply microgrid containing wind curtailment.

The present invention relates to the field of power grid dispatching control, in particular to a regional power grid optimal load control method considering regional balance, which is characterized in that it includes the following steps: A) obtaining the total amount of load control; B) calculating the target amount of load removal in each area; C) Select the line to be pulled from the pull-limit sequence table; D) Construct the full load shedding model and the short load shedding model; E) Build the regional load balance model; F) Calculate the full load cut off and short load in each area Cut-off and regional load balance value; G) Output the cut-off lines in each region; the region refers to the county-level power supply units and district-level power supply units within the jurisdiction of the regional power grid. The beneficial effects of the present invention are: on the basis of satisfying the shedding load, the total shedding load can be reduced, excessive shedding can be avoided, economy and regional fairness can be effectively taken into account, the load shedding can be reduced to the greatest extent, and the power grid can be fully guaranteed Scheduling fairness.

An Automatic load-reducing control method for integrating the voltage frequency dynamic mutual influence measures the state quantity information on site such as voltage, frequency and power so as to determine whether to act for implementing the load-reducing. The invention effectively takes account of the coupling degree of the voltage amount and the frequency amount under the corresponding operating condition by calculating the average frequency voltage correlation coefficient at the device installation nodes under a certain operating condition; calculating the synthetic state quantity in real time by measuring the voltage, frequency and active power of the installation node of each automatic load-reducing control device in real time and starting the automatic load-reducing control devicein time based on the change circumstance, and acting in turn. The invention introduces the active power measurement into the traditional automatic load-reducing device, takes account of the interaction of the voltage and the frequency generated by the load active power and solves the problem that the device may not act or act excessively only based on the change of the frequency amount or the voltage amount.

Provided is a power distribution network single-phase earth fault network reconstruction method. The power distribution network single-phase earth fault network reconstruction method comprises the following steps: after earth fault, all power restoration zones are divided into two groups, branch circuits locating in the same section bus with fault circuits are divided into a group A, and power restoration circuits locating in different section buses are divided into a group B; for all power restoration circuits of the two groups, on the premise of voltage meeting constraint conditions, a power restoration circuit with a smallest network loss value in the group A is preferentially selected to avoid power failure in the power restoration process, a hot switch operation is conducted at the moment, namely, bus interconnection switches are closed, and then circuit breakers in failure positions are tripped off. For power restoration circuits of the group B, a cold switch operation is conducted, namely, the circuit breakers in the failure positions are tripped off, and then the bus interconnection switches are closed. The power distribution network single-phase earth fault network reconstruction method preferentially selects the hot switch operation which fully uses characteristics of single-phase earth faults, so that a power distribution network can operate in a normal condition or with faults. Besides, the power distribution network single-phase earth fault network reconstruction method ensures power supply quality of users, improves reliability of power supply, and has high operability and superiority. The power distribution network single-phase earth fault network reconstruction method is mature in technology and high in reliability.

The present invention belongs to a method for optionally cutting off a fault point of double branch circuits at the low voltage side of a transformer, which comprises the following steps of: (1) when earthed fault occurs, measuring instantaneous values of current I0 of an earthed neutral point and an triphase current of each branch at the low voltage side of the transformer; (2) calculating amplitude values of the I0 and zero-sequence current I01 and I02 of two branches at the lower voltage side of the transformer; (3) automatically analyzing the relation between the amplitude values of I0, I01 and I02; and (4) according to an analyzing result of the step (3), enabling a corresponding circuit breaker to actuate by sections and time delay to complete the cutoff of the failed branch. The method carries out discrimination by utilizing the distribution feature of zero-sequence fault current flowing through two branches at the low voltage side of the transformer when low-resistance earthed fault occurs and intelligently identifies the faulted branch circuit at the low voltage side of the transformer; and compared with the prior protection proposal, the method effectively shortens the load cutting range, improves the reliability of power supply for a user, reduces the blackout range caused when the earthed fault is earthed and changed into zero-sequence protecting action and protects the power load as large as possible.