CN102591276A - Intelligent electric meter system for residents for intelligent smart grid - Google Patents

Abstract

The invention discloses a residential user smart meter system suitable for a smart grid. It is a smart meter system for residential users suitable for smart grids. It installs a smart meter in each resident's home, and installs a control terminal at each controllable home appliance and user switch. A distributed power access device is installed at the distributed power supply; the smart meter is interconnected with each control terminal and distributed power access device through the PLC communication network, and the smart meter exchanges information with the advanced measurement system AMI of the master station . It is suitable for residential users who implement tiered electricity prices and time-of-use electricity prices. With the goal of minimizing user electricity bills, it intelligently controls household appliances and distributed power supplies for residential users, realizes peak-shaving and valley-filling of power loads, and improves power supply quality and reliability.

Description

A Residential User Smart Meter System Applicable to Smart Grid

technical field

The invention relates to the fields of smart homes, smart meters and smart grids, in particular to a smart meter system for residential users suitable for smart grids.

Background technique

In the era of smart grid, with the help of advanced information and communication technology, it is possible to perform load response according to dispatching requirements, which can solve the large-scale access of clean energy to the grid. All loads of power users, especially elastic loads, are no longer randomly put into the grid, but Organized and planned to invest in the power grid. See Yin Shugang, Miao Wenjing, Bai Keming (Yin Shugang, Miao Wenjing, Bai Keming). Author: Discussion of quasi real-time price strategy. Power DSM, 2011, 13( 1): 20-23. This requires information interaction between the power supply department and residential users, allowing power users to actively participate in the power market and power services, and realizing peak-shaving and valley-filling of power loads to improve power supply quality and reliability. Due to the large number of residential users, 40% of the user load is elastic load, and there is a large margin for power consumption time selection; moreover, with the development of distributed power, distributed power will penetrate into thousands of households. Therefore, according to the current ladder price and The time-of-use electricity price can enable residents to use electricity in low valleys, reduce peak electricity consumption, and encourage residential users to connect to distributed power generation and energy storage equipment to participate in peak shaving and valley filling. Residents are required to make optimal input and operation decisions for household appliances based on the ladder electricity price and time-of-use electricity price. If the decision is made manually, the user needs to invest a large amount of work, which cannot be realized. Smart meters are required to make intelligent decisions on the control of household appliances and distributed power sources. Traditional smart meters can at most achieve bidirectional metering functions and do not have intelligent decision-making functions. Therefore, it is of great significance to design a smart meter that realizes intelligent control of household appliances based on tiered electricity prices and time-of-use electricity prices.

Contents of the invention

The purpose of the present invention is to overcome the inability of traditional smart meters to charge household users according to the ladder electricity price and time-of-use electricity price; the inability to realize the intelligent control of household appliances according to the ladder electricity price and time-of-use electricity price, so as to make the electricity fee the lowest; To solve the problem of realizing intelligent control of distributed power sources with the time-of-use electricity price and maximizing their income, the invention provides a smart meter system for residential users suitable for smart grids, which can realize peak-shaving and valley-filling of power loads, improve power supply quality and power supply reliability.

To achieve the above object, the present invention adopts the following technical solutions:

A smart meter system for residential users suitable for smart grids. A smart meter with bidirectional metering function is installed in each resident's home, and a control terminal is installed at each controllable home appliance and user switch. A distributed power access device is installed at each distributed power supply. The smart meter is connected to the control terminal and the distributed power access device through the PLC communication network, and the smart meter is also connected to the controllable home appliances; The master station is interconnected through Ethernet, and exchanges information with the advanced measurement system AMI of the master station, controls the control terminal and the distributed power access device, and monitors the switch status of the user.

The smart meter includes a main control module, a data processing module, a metering module, an electrical quantity input module, a touch screen module, a storage module, a real-time clock module, an Ethernet module, a PLC communication module and an RS232/485 module; the main control module is mainly responsible for communication And man-machine interface, to realize the input and output of the touch screen, the storage of historical data, the freezing of monthly power, Ethernet communication, PLC communication, RS232/485 communication and real-time clock input, the real-time clock module realizes the real-time clock input of the perpetual calendar; the data processing module is responsible for Electric energy metering, electricity cost calculation, data acquisition of current and voltage electrical quantities, digital filtering and voltage effective value, current effective value, power factor, active power and reactive power calculation; according to ladder electricity price, time-of-use electricity price, controllable home appliances and distribution Formulate the optimal working time period decision for controllable household appliances and distributed power supply; make protection decisions for household appliances according to the current electrical parameters; send the decision results to the main control module, which realizes the protection of household appliances best control.

Described main control module adopts MCF5272 chip, and data processing module adopts DSP chip and large-scale field programmable logic array FPGA, communicates through DMA between DSP chip and MCF5272 chip; Analog voltage and current signal are converted through analog input transformer or flying capacitor, and then Filtering, and then selected by an 8-select 1CMOS multiplexer, the output of the multiplexer is driven by a voltage follower amplifier, and sent to a high-speed 16-bit A/D converter for conversion into digital quantities, and the output of the A/D is serial data The form of stream is sent to DSP for processing, and 128 points are sampled per cycle.

The control terminal adopts the on-chip system MC13213. After the terminal receives the power on and off command of the controller through PLC communication, it controls the electromagnetic relay through the output drive circuit MC1413, and controls the power on and off of the controllable household appliances; the state of the electromagnetic relay is passed through the photoelectric isolator. Then send it to MC13213 to realize the on-off power status monitoring of controllable home appliances; the temperature measurement of home appliances uses digital temperature sensor DS18B20, which is sent to MC13213 for processing through serial data stream.

The smart meter also supports tiered electricity price, time-of-use electricity price and monthly electricity freezing, and calculates the electricity consumption fee for residential users according to the tiered electricity price, time-of-use electricity price information and the user's electricity consumption information.

The smart meter acquires tiered electricity prices, time-of-use electricity prices, home appliance types, home appliance operating hours, residents' expectations for home appliance operating status, and ambient temperature conditions from the main station, calculates the electricity expenses for home appliances operating in each time period of the day, and takes the lowest electricity expense. The time period is used as the time period for the home appliance to run, and the smart meter sends input commands to the control terminal of the home appliance department through the PLC communication method to achieve the lowest control of the operating cost of the home appliance.

The smart meter calculates the profit and loss of the distributed power supply into operation according to the ladder electricity price, time-of-use electricity price, kWh electricity subsidy, distributed power supply operating cost and distributed power generation output obtained from the main station; if the profit and loss value is greater than 0, and the distribution If the distributed power supply meets the maximum allowable capacity limit of the access point, the smart meter will send an input command to the access device of the corresponding distributed power supply through the PLC communication method, so that the corresponding distributed power supply will be put into operation; if the profit and loss value is less than 0, the Distributed power generation stops operating.

The operating electricity expenses of the household appliances in each time period;

Z _a =Z _th +Z _ad (1)

${\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; the\; th</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; \&alpha;C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; P\&Delta;t</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Greater\; Equal;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\\ {\mathrm{<span\; class="notranslate">\; \&alpha;C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; P\&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&alpha;C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; ad</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\frac{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}}{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Greater\; Equal;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\\ \frac{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}}{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\\ \frac{\mathrm{<span\; class="notranslate">\; twenty\; four</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Greater\; Equal;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\\ \frac{\mathrm{<span\; class="notranslate">\; twenty\; four</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\text{<span class="notranslate"> 3</span>}<span\; class="notranslate">\; )</span>$

in, $C_{\mathrm{Si}}=\left\{\begin{array}{cc}{C}_V,& t_r\&Subset;t_V\\ C_f,& t_r\&Subset;t_f\\ C_P,& t_r\&Subset;t_P\end{array}\right.;$ $\mathrm{\&alpha;}=\left\{\begin{array}{cc}{C}_I/C_{\mathrm{II}},& W\&Element;W_I\\ 1,& W\&Element;W_{\mathrm{II}}\\ C_{\mathrm{III}}/C_{\mathrm{II}},& W\&Element;W_{\mathrm{III}}\end{array}\right.$

Z _a is the actual electricity expense of home appliances; Z _th is the theoretical electricity expense of home appliances; Z _ad is the additional electricity expense required by home appliances due to the energy loss caused by the completion of operation in advance; α is the ladder electricity price coefficient; C _S1 is the end of the electric heater The time-of-use electricity price of the heating time period; C _S2 is the time-of-use electricity price of the time period before the end of the heating time of the electric heater; P is the power of the home appliance; Δt is the running time of the home appliance; At _S1 is the end of the heating time of the electric heater time period; t _{e is} the time when the home appliance is expected to run; t _c is the time when the home appliance theoretically runs; t _i is the time required for the temperature of the home appliance to drop or rise by 1°C; Reduce the power consumption by 1°C; C _Si is the time-of-use electricity price of the i-th time period; C _V , _CF , and C _P are the valley, flat and peak electricity prices of the day; t _r is the running time interval of household appliances; t _V , t _F and t _P are the valley, flat and peak electricity price time periods of the day respectively; C _I , C _II , and C _III are respectively the electricity price of the first level, the second level and the third level of the current month; W is the actual consumption from the beginning of this month to the present ; W _I , W _II , and W _III are respectively the current month's level I, level II, and level III ladder electricity; for household appliances related to running time and ambient temperature, electricity expenses are calculated according to formula (1); For household appliances that have nothing to do with temperature, the electricity expense is calculated according to the formula (2); the time period with the lowest electricity expense in the operation of the appliance is taken as the final control time for the appliance to be put into operation; the control method adopts the power carrier PLC method, and is realized by controlling the control terminal of the appliance The input or exit operation of household appliances; the control of electric vehicle charging, according to the ladder electricity price, time-of-use electricity price, electric vehicle battery status and user expectations for the charging status of the rechargeable battery, determine the final charging time period, and control the distributed power supply connection. The input device realizes the input or exit control of the electric vehicle.

Profit and loss of distributed power generation operation:

Y＝W _DG (αC _S +SR) (4)

Among them, W _DG represents the power generation of distributed power generation, which is transmitted to the smart meter by the distributed power access device through PLC; α is the ladder electricity price coefficient; C _S is the time-of-use electricity price; These three parameters are transmitted by the AMI of the main station to the smart meter of the residential user through Ethernet; R is the operating cost of each kilowatt-hour of electricity generated by the distributed power supply, including the depreciation fee and maintenance fee of the equipment; when the calculated operating profit and loss value Y is greater than When 0, it means that the distributed power supply can be profitable after being put into operation, and the distributed power supply can be put into operation, otherwise, the distributed power supply will be cut off;

The access capacity of the distributed power supply cannot exceed the maximum allowable capacity of the access point, that is, the input capacity of the distributed power supply is constrained by the following formula

P _DG ≤ P _max (5)

Among them, P _DG is the total power of all distributed power sources connected; P _max is the maximum access capacity allowed by the distributed power access point, and this parameter is obtained from the master station through Ethernet.

Residential smart meters calculate the operating profit and loss of formula (4) in real time. If the profit and loss value Y is greater than 0 and satisfies formula (5), the distributed power supply with a capacity of P _DG is put into operation. If formula (5) is not satisfied, The distributed power supply with a capacity of P _max is put into operation; the distributed power supply is put into operation by the smart meter of the resident user using the PLC method to send the start-up operation command to the corresponding distributed power access device, so that the distributed power supply is put into operation.

For tiered electricity price and time-of-use electricity price, the following formula is used for electricity fee calculation:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}}\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; D.</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}\\ {\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}}<span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; D.</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}\\ {\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}}<span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}}<span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; D.</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; ></span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Among them, Z _M is the actual electricity fee expenditure of this month; C _I , C _II , and C _III are respectively the electricity price of the first level, the second level and the third level of the current month; C _Sdg is the g-th day of the d-th day in January The time-of-use electricity price of the segment; W _dg is the electric energy consumed in the g-th segment of the d-th day in January; W _M is the electricity consumed in this month; W _I , W _II , and W _III are respectively the I level of this month , level II and level III ladder electricity; D is the number of days in this month; G is the number of segments divided by time-of-use electricity price in one day; U ₁ , V ₁ , U ₂ and V ₂ are the U _1st day in January V ₁ period and V ₂ period on the U _2nd day, and satisfy the following formula:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}\\ {\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; .</span>$

The present invention obtains information on ladder electricity price and time-of-use electricity price from the master station through Ethernet, and the smart meter calculates the running time of home appliances in each time period according to conditions such as electricity price information, home appliance type, home appliance running time, residents' expectations for home appliance operating status, and ambient temperature. Electricity expense, take the time period with the lowest electricity expense as the time period for the home appliance to run. At the beginning of the running time period, the power carrier (PLC) communication method is used to send an operation command to the control terminal of the home appliance to put the home appliance into operation; when the running time is up, the smart meter sends an exit operation command to the control terminal of the home appliance , to stop the appliance from operating. At the same time, the smart meter calculates the profit and loss of the distributed power supply in operation based on the electricity price information, the electricity subsidy per kilowatt-hour, the operating cost of the distributed power supply per kilowatt-hour, and the power generation of the distributed power supply. If the profit and loss value is greater than 0, and the distributed power supply meets the maximum allowable capacity limit of the access point, the smart meter will send a commissioning command to the access device of the corresponding distributed power supply through the power carrier (PLC) communication method, so that the corresponding distribution The distributed power supply is put into operation; if the profit and loss value is less than 0, the distributed power supply will stop running. In addition, the smart meter can realize two-way metering function and monthly power freezing function.

Beneficial effects of the present invention: the present invention is suitable for residential users who implement ladder electricity prices and time-of-use electricity prices. With the goal of minimizing user electricity expenses, intelligently control household appliances and distributed power supplies for residential users, and realize peak-shaving and valley-filling of power loads. Improve power supply quality and power supply reliability.

Description of drawings

Fig. 1 is a structural block diagram of the smart meter control system of the present invention;

Fig. 2 is a block diagram of the smart meter function module of the present invention;

Fig. 3 is a hardware structural diagram of the smart meter of the present invention;

Fig. 4 is the hardware structural diagram of the control terminal of the present invention;

Fig. 5 is a software flowchart of the smart meter controller of the present invention.

Detailed ways

The invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The resident user smart meter system suitable for the smart grid proposed by the present invention is realized through the following technical scheme, and the steps include:

FIG. 1 is a structural block diagram of the smart meter control system of the present invention. The system takes the smart meter as the control core, and the smart meter interacts with the advanced measurement system (AMI) of the main station through Ethernet, obtains the ladder electricity price and time-of-use electricity price information from the AMI, and reports the electric energy and electricity cost consumed by the user to the AMI. And operating parameters such as voltage, current and power factor, for AMI to determine the time-of-use electricity price according to the user load. The smart meter determines the optimal operating time period of the controllable home appliances according to the ladder electricity price, time-of-use electricity price and the situation of the controllable home appliances. Putting into operation command, the control terminal closes the electromagnetic relay controlling the home appliances, so that the corresponding home appliances are put into operation. At the same time, the smart meter calculates the time period when the profit and loss value of the distributed power supply is greater than 0 according to the ladder electricity price, time-of-use electricity price, distributed power supply operating cost and electricity price subsidy. The PLC communication method issues the distributed power supply operation command to the distributed power supply access device, so that the corresponding distributed power supply is put into operation. The smart meter calculates the electricity bill for this month based on the tiered electricity price, time-of-use electricity price, and the electricity consumed in each time period, and reports the AMI of the master station through Ethernet to realize the remote meter reading function. The smart meter obtains the user's voltage and current status from the secondary side of the voltage transformer (PT) and current transformer (CT), and calculates the power factor, and reports these electrical parameters to the AMI of the master station through Ethernet, so that the master station can Adjust electrical parameters to improve power supply quality. At the same time, the smart meter realizes overvoltage, overcurrent, undervoltage and leakage protection according to the detected voltage and current. If a corresponding fault occurs, the smart meter sends a trip command to the control terminal at the user switch through PLC communication, so The user switch is disconnected to protect household appliances. Each control terminal reports the status of each switch to the smart meter through PLC line communication, so that the smart meter can monitor the status of each switch.

Figure 2 is a block diagram of the functional modules of the smart meter of the present invention. The smart meter is composed of: main control module, data processing module, metering module, analog input module, touch screen module, storage module, clock module, Ethernet module, PLC communication module and RS232/485 module. The main control module is mainly responsible for communication and man-machine interface, to realize the input and output of the touch screen, the storage of historical data, the freezing of monthly power, Ethernet communication, PLC communication, RS232/485 communication and real-time clock input. The real-time clock module realizes the perpetual calendar real-time clock enter. The data processing module is responsible for electric energy metering, electricity cost calculation, data acquisition of current and voltage electrical quantities, digital filtering and calculation of effective value of voltage, effective value of current, power factor, active power and reactive power, etc.; Controllable household appliances and distributed power supply conditions, formulate optimal working time period decisions for controllable household appliances and distributed power supplies; make protection decisions for household appliances based on current electrical parameters; send decision results to the main control module, and the main control module Realize optimal control of household appliances.

FIG. 3 is a hardware structure diagram of the smart meter of the present invention. The main controller adopts the 32-bit microprocessor MCF5272CVF66 of Freescale Company; the data processor adopts ADSP-2185, a highly integrated single-chip digital signal processor of AD Company, which communicates with the main controller through DMA; The large-scale field programmable logic array FPGA realizes the logic control of the system; the metering chip selects the multifunctional low-power metering chip MAXQ3180 produced by Maxim; it adopts 256K bytes of static read-write memory (SRAM), 16M bytes of SDRAM, 4M words Power-saving erasable flash memory (FLASH RAM), among them, SDRAM is the working memory of the main controller, SRAM is used to store important historical data; flash memory is used to save the device running bootloader, operating system, application program, DSP programs, configuration files, etc. In the analog input channel, the voltage and current signals are converted by analog input transformers or flying capacitors, then filtered, and then selected by an 8-select 1 CMOS multiplexer. The output of the multiplexer is driven by a voltage follower amplifier and sent to a high-speed 16-bit A/D converter is converted into digital quantity, and the output of A/D is sent to DSP for processing in the form of serial data stream. In order to improve the sampling accuracy, 128 points are sampled per cycle. The PLC interface adopts SSC P300, a spread spectrum transceiver communication chip based on power carrier produced by Intellon Company of the United States; the real-time clock adopts DS1302 of DALLAS Company of the United States; the Ethernet interface adopts the Ethernet port module AX11001 of Taiwan Asix Company; the touch screen adopts the touch screen control of TI Company device ADS7846.

FIG. 4 is a hardware structural diagram of the control terminal of the present invention. The control terminal adopts Freescale's on-chip system MC13213. After receiving the power on and off command from the controller through PLC communication, the terminal controls the electromagnetic relay through the output drive circuit MC1413 to control the power on and off of the controllable household appliances; the state of the electromagnetic relay is passed through the photoelectric The isolator is sent to the MCU to realize the on-off power status monitoring of the controllable home appliances; the temperature measurement of the home appliances uses a digital temperature sensor DS18B20, which is sent to the MC13213 for processing through the serial data stream.

FIG. 5 is a software flowchart of the smart meter controller of the present invention. The main program determines the optimal operating time period of the controllable home appliances and distributed power sources according to the ladder electricity price, time-of-use electricity price and the status of the controllable home appliances and distributed power sources obtained from the main station. According to the optimal running time period, corresponding commands are sent to the control terminal of the corresponding home appliance or the distributed power access device. The sending command adopts the interrupt method, and the interrupt is divided into two types, one is the interrupt at the beginning of the running time period, and the other is the interrupt at the end of the running time period. When the corresponding time is up, enter the corresponding interrupt service subroutine, control the corresponding home appliance control terminal or distributed power supply access device, and make the corresponding home appliance or distributed power supply put into or out of operation.

In order to specifically describe the technical implementation scheme of the smart meter for residential users, the following uses a household electric water heater as an example to describe in detail. Suppose the power of the electric water heater is 2000W, the capacity is 60L, the initial temperature of the water in the electric water heater is 20°C, and the final temperature after heating by the electric water heater is 45°C. The energy required for heating is then:

Q=cmΔT=4.2×10 ³ ×60×(45-20)=6.3×10 ⁶ J=1.75kWh (8)

The time required for heating is:

$\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; W</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Q</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1.75</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.875</span>}\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 52.5</span>}\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

Assuming that the user expects the electric water heater to finish heating at 21:45, after the heating is completed, the water temperature of the electric water heater will decrease by 1°C every 4 hours, and the corresponding energy loss is:

ΔQ=cmΔT=4.2×10 ³ ×60×1=2.52×10 ⁵ J=0.07kWh (10)

Assume that the ladder electricity price of the current month is shown in Table 1, and the time-of-use electricity price of the current day is shown in Table 2. Assuming α=1, the theoretical electricity expenses of the electric heater in each time period calculated according to the formula (2) are shown in Table 2. Because if the electric water heater completes heating at the end time of each time-of-use electricity price, the additional energy consumed is the smallest, so the heating completion time of the electric water heater is set at the end time of the corresponding time-of-use electricity price, and the heating start time of the electric water heater is time-of-use The heating time of the electric water heater is subtracted from the end time of the electricity price. If the electric water heater finishes heating ahead of time, there will be energy loss, and additional electricity expenses will be required. The additional electricity expenses calculated according to formula (3) for the operation of the electric heater in each time period are shown in Table 2. According to the formula (1), the actual electricity expenses when the electric heater is running in each time period are shown in Table 2. It can be seen from Table 2 that the electric heater completes the heating at 7:00 and the actual expenditure is the least, so the initial operating time of the electric heater is: 7-0.875=6.125, that is, the electric heater is put into operation at 6:07:30, The actual expenditure on electricity was 0.8434. Due to the energy loss between the completion of heating at 7:00 and the user's use time at 21:45, the temperature of the water needs to be heated to higher than 45°C to meet the water temperature requirement of 45°C when the user uses it. Therefore, the electric heater needs to be heated in advance, and the advance time is:

${\mathrm{<span\; class="notranslate">\; t</span>}}^{<span\; class="notranslate">\; \text{'}</span>}<span\; class="notranslate">\; =</span>\frac{\frac{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}}{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}}{\mathrm{<span\; class="notranslate">\; P</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 60</span>}<span\; class="notranslate">\; =</span>\frac{\frac{\mathrm{<span\; class="notranslate">\; 21.75</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 7</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 0.07</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 60</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 7.74375</span>}\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 11</span>}<span\; class="notranslate">\; )</span>$

Therefore, when the actual operating time of the electric heater is: 6:07:30-0:07:45=5:59:45, the heating end time is: 7:00.

Table 1 Tiered electricity price

power level Power W(kWh) Electricity price C (yuan) Tier I 0-140 0.36 Tier II 140-270 0.6 Class III ＞270 0.9

Table 2 Time-of-use electricity price and electricity expense of electric water heater

time 0:00-7:00 7:00-10:00 10:00-15:00 15:00-18:00 18:00-21:00 21:00-23:00 23:00-24:00 Time-of-use electricity price (yuan) 0.42 0.6 0.75 0.6 0.75 0.6 0.42 Theoretical expenditure (yuan) 0.735 1.05 1.3125 1.05 1.3125 1.0875 0.735 Additional expenses (yuan) 0.1084 0.1234 0.0886 0.0394 0.0098 0 0.1599 Actual expenditure (yuan) 0.8434 1.1734 1.4011 1.0894 1.3223 1.0875 0.8949

Claims (10)

1. A smart meter system for residential users suitable for smart grids, characterized in that a smart meter with two-way metering function is installed in the home of each resident, and each controllable home appliance and user switch are installed Set up a control terminal, and install a distributed power access device at each distributed power supply. The smart meter is interconnected with the control terminal and the distributed power access device through the PLC communication network. The smart meter is also connected to the controllable power supply. Home appliance connection; the smart meter is interconnected with the main station through Ethernet, exchanges information with the advanced measurement system AMI of the main station, controls the control terminal and the distributed power access device, and monitors the switch status of the user. 2. The residential user smart meter system suitable for smart grids according to claim 1, wherein the smart meter includes a main control module, a data processing module, a metering module, an electrical quantity input module, a touch screen module, and a storage module , real-time clock module, Ethernet module, PLC communication module and RS232/485 module; the main control module is mainly responsible for communication and man-machine interface, to realize the input and output of the touch screen, storage of historical data, monthly power freezing, Ethernet communication, PLC Communication, RS232/485 communication and real-time clock input, the real-time clock module realizes the perpetual calendar real-time clock input; the data processing module is responsible for electric energy metering, electricity bill calculation, data acquisition of current and voltage electrical quantities, digital filtering and voltage effective value, current effective value, Calculation of power factor, active power and reactive power; formulate the optimal working time period decision for controllable home appliances and distributed power according to ladder electricity price, time-of-use electricity price, controllable home appliances and distributed power supply; The protection decision of household appliances; the decision result is sent to the main control module, and the main control module realizes the optimal control of household appliances. 3. The residential user smart meter system suitable for smart grid as claimed in claim 2, wherein the main control module adopts MCF5272 chip, and the data processing module adopts DSP chip and large-scale field programmable logic array FPGA, DSP The chip communicates with the MCF5272 chip through DMA; the analog voltage and current signals are converted by analog input transformers or flying capacitors, then filtered, and then selected by an 8-to-1 CMOS multiplexer. The output of the multiplexer is driven by a voltage follower amplifier. Send it to a high-speed 16-bit A/D converter to convert it into a digital quantity, and the output of the A/D is sent to the DSP in the form of a serial data stream for processing, with 128 points per cycle sampling. 4. The smart meter system for residential users suitable for smart grids as claimed in claim 1, wherein the control terminal adopts a system-on-chip MC13213, and after the terminal receives the on-off power command of the controller through PLC communication, it passes The output drive circuit MC1413 controls the electromagnetic relay to control the power on and off of the controllable household appliances; the state of the electromagnetic relay is sent to MC13213 through the photoelectric isolator to realize the monitoring of the power on and off of the controllable household appliances; the temperature measurement of the household appliances adopts the digital temperature sensor DS18B20 , sent to MC13213 for processing through the serial data flow. 5. The smart meter system for residential users suitable for smart grids as claimed in claim 1, wherein the smart meter supports tiered electricity prices, time-of-use electricity prices, and monthly electricity freezing, and according to the ladder electricity prices and time-of-use electricity prices information and The user's electricity consumption information is used to calculate the electricity consumption fee for residential users. 6. The smart meter system for residential users suitable for smart grids as claimed in claim 1, wherein the smart meter obtains from the main station the ladder electricity price, time-of-use electricity price, type of home appliance, running time of home appliances, and operation of residents to home appliances. The expected value of the state and the ambient temperature conditions, calculate the electricity expenditure of the household appliances in each time period of the day, and take the time period with the lowest electricity expenditure as the time period of the household appliance operation, and the smart meter sends input commands to the control terminal of the household appliances through PLC communication. Realize the lowest control on the operating cost of home appliances. 7. The smart meter system for residential users suitable for smart grids according to claim 1, wherein the smart meter is based on the ladder electricity price, time-of-use electricity price, kWh electricity subsidy, and distributed power supply operating cost obtained from the master station. Calculate the profit and loss of the distributed power supply and the power generation of the distributed power supply; if the profit and loss value is greater than 0, and the distributed power supply meets the maximum allowable capacity limit of the access point, the smart meter will report to the corresponding distributed power supply The access device sends an input command to put the corresponding distributed power supply into operation; if the profit and loss value is less than 0, the distributed power supply will stop running. 8. The resident user smart meter system suitable for smart grids as claimed in claim 6, characterized in that, the operating electricity charges of the household appliances in each time period; Z _a =Z _th +Z _ad (1) ${\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; the\; th</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; \&alpha;C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; P\&Delta;t</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Greater\; Equal;</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\\ {\mathrm{<span\; class="notranslate">\; \&alpha;C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; P\&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&alpha;C</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

in, $C_{\mathrm{Si}}=\left\{\begin{array}{cc}{C}_V,& t_r\&Subset;t_V\\ C_f,& t_r\&Subset;t_f\\ C_P,& t_r\&Subset;t_P\end{array}\right.;$ $\mathrm{\&alpha;}=\left\{\begin{array}{cc}{C}_I/C_{\mathrm{II}},& W\&Element;W_I\\ 1,& W\&Element;W_{\mathrm{II}}\\ C_{\mathrm{III}}/C_{\mathrm{II}},& W\&Element;W_{\mathrm{III}}\end{array}\right.$ Z _a is the actual electricity expense of home appliances; Z _th is the theoretical electricity expense of home appliances; Z _ad is the additional electricity expense required by home appliances due to the energy loss caused by the completion of operation in advance; α is the ladder electricity price coefficient; C _S1 is the end of the electric heater The time-of-use electricity price of the time period of the heating time; C _S2 is the time-of-use electricity price of the time period before the end of the heating time of the electric heater; P is the power of the home appliance; Δt is the running time of the home appliance; Δt _S1 is the end of the heating time of the electric heater time period; t _{e is} the time when the home appliance is expected to run; t _c is the time when the home appliance theoretically runs; t _i is the time required for the temperature of the home appliance to drop or rise by 1°C; Reduce the power consumption by 1°C; C _Si is the time-of-use electricity price of the i-th time period; C _V , _CF , and C _P are the valley, flat and peak electricity prices of the day; t _r is the running time interval of household appliances; t _V , t _F and t _P are the valley, flat and peak electricity price time periods of the day respectively; C _I , C _II , and C _III are respectively the electricity price of the first level, the second level and the third level of the current month; W is the actual consumption from the beginning of this month to the present ; W _I , W _II , and W _III are respectively the current month's level I, level II, and level III ladder electricity; for household appliances related to running time and ambient temperature, electricity expenses are calculated according to formula (1); For household appliances that have nothing to do with temperature, the electricity expense is calculated according to the formula (2); the time period with the lowest electricity expense in the operation of the appliance is taken as the final control time for the appliance to be put into operation; the control method adopts the power carrier PLC method, and is realized by controlling the control terminal of the appliance The input or exit operation of household appliances; the control of electric vehicle charging, according to the ladder electricity price, time-of-use electricity price, electric vehicle battery status and user expectations for the charging status of the rechargeable battery, determine the final charging time period, and control the distributed power supply connection. The input device realizes the input or exit control of the electric vehicle. 9. The residential user smart meter system suitable for smart grids as claimed in claim 7, wherein the profit and loss of the distributed power supply when put into operation: Y＝W _DG (αC _S +SR) (4) Among them, W _DG represents the power generation of distributed power generation, which is transmitted to the smart meter by the distributed power access device through PLC; α is the ladder electricity price coefficient; C _S is the time-of-use electricity price; These three parameters are transmitted by the AMI of the main station to the smart meter of the residential user through Ethernet; R is the operating cost of each kilowatt-hour of electricity generated by the distributed power supply, including the depreciation fee and maintenance fee of the equipment; when the calculated operating profit and loss value Y is greater than When 0, it means that the distributed power supply can be profitable after being put into operation, and the distributed power supply can be put into operation, otherwise, the distributed power supply will be cut off; The access capacity of the distributed power supply cannot exceed the maximum allowable capacity of the access point, that is, the input capacity of the distributed power supply is constrained by the following formula P _DG ≤ P _max (5) Among them, P _DG is the total power of all distributed power sources connected; P _max is the maximum access capacity allowed by the distributed power access point, and this parameter is obtained from the master station through Ethernet. Residential smart meters calculate the operating profit and loss of formula (4) in real time. If the profit and loss value Y is greater than 0 and satisfies formula (5), the distributed power supply with a capacity of P _DG is put into operation. If formula (5) is not satisfied, The distributed power supply with a capacity of P _max is put into operation; the distributed power supply is put into operation by the smart meter of the resident user using the PLC method to send the start-up operation command to the corresponding distributed power access device, so that the distributed power supply is put into operation. 10. The residential user smart meter system suitable for smart grids as claimed in claim 6 or 7, characterized in that, for tiered electricity prices and time-of-use electricity prices, the following formula is used to calculate electricity charges $\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}}\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; D.</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}\\ {\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}}<span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; D.</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}\\ {\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}}<span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{{\mathrm{<span\; class="notranslate">\; g</span>}}_{}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}}<span\; class="notranslate">\; (</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; D.</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; Sdg</span>}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; ></span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$ Among them, Z _M is the actual electricity fee expenditure of this month; C _I , C _II , and C _III are respectively the electricity price of the first level, the second level and the third level of the current month; C _Sdg is the g-th day of the d-th day in January The time-of-use electricity price of the segment; W _dg is the electric energy consumed in the g-th segment of the d-th day in January; W _M is the electricity consumed in this month; W _I , W _II , and W _III are respectively the I level of this month , level II and level III ladder electricity; D is the number of days in this month; G is the number of segments divided by time-of-use electricity price in one day; U ₁ , V ₁ , U ₂ and V ₂ are the U _1st day in January V ₁ period and V ₂ period on the U _2nd day, and satisfy the following formula: $\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}\\ {\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; II</span>}}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; G</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\overset{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; w</span>}}_{\mathrm{<span\; class="notranslate">\; d\; g</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; .</span>$

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