WO2010045790A1

WO2010045790A1 - Load limiter device

Info

Publication number: WO2010045790A1
Application number: PCT/CN2009/070151
Authority: WO
Inventors: Shiva Kumar Shrestha; Ram Prasad Rimal; Laxman Prasad Rimal; Karna Bahadur Bhandari
Original assignee: Shrestha, Rajendra Kumar
Priority date: 2008-10-20
Filing date: 2009-01-14
Publication date: 2010-04-29

Abstract

A load limiter device. The device provides a plurality of electrical energy supply paths with different capacities. The plurality of paths are comprised of at least one relay, contactor, automatic changeover switch or breaker connected in series and /or parallel. The device further comprises a receiver to receive control signals and select the paths according to the control signals.

Description

LOAD LIMITER DEVICE

FIELD OF THE INVENTION

The present invention relates to electrical energy supplying field and, more particularly to supplying electrical energy with circuit paths having different capacities so as to supply electrical energy for consumers divided in a priority based and group wise without power cut in the time of energy deficit.

BACKGROUND OF THE INVENTION

The different source of electrical energy have different generation

pattern. The electrical energy cannot store in efficient way. The production

and consumption are simultaneous process. The Demand pattern reflects

socio-economical, geographical condition of a country. The activity of

human will differ with season as well as hour of day; hence the demand

varies i.e. the demand period are classified as peak hours, mid-peak

(normal) hours and off peak hours. Conversely, the electrical energy

generation is more linear in a day. In hydro-electrical energy, the energy

generation capacity of a power house changes as season changes because

of water discharge. The generation capacity of most hydro power plant

will drop to 50%-65% in winter season where as the demand increases

than rainy season / almost same (See Fig. 62 & 64). The installed

capacities of hydro power plants are designed based on hydrological data

of rainy season. Because of nature of demand and generation (electrical energy generation in hydro), either spill energy or energy deficit situation always exist. The deficit of energy in a day is classified as capacity deficit and energy deficit. The total energy demand during a day is equal or less than the total energy can be generated during that day but the peak demand is higher than the energy can generate in that hour then it is called capacity deficit (See Figs. 60 & 61). If the total energy demand is higher than the total energy generation capacity within a day is called energy deficit. When there is energy deficit, there is capacity deficit too. But if there is capacity deficit, it is not necessary to be energy deficit. The spill energy is not utilizing properly. To manage energy deficit situation, rolling power cut technique is applied by power provider and consumers are suffering by blackout. Because of blackout, they cannot use basic light. Without basic light, the life is more difficult for household consumer. The majority of consumers are house hold. The supply side management should be improved in such a way that energy for at least basic load should available to every consumer when energy is deficit.

(Fig.I)

As per Annual Report 2063/64 of System Operation Department of Nepal Electricity Authority (NEA), Fig. 62, the spill energy in Shrawan was 65.90GWh (65900MWh) and from Fig. 64 the energy generation in Shrawan was 260,373MWh. The total generation capacity in Shrawan was 326,273MWh and the actual energy generated in Falgun was 166,973MWh (Fig. 64). The energy generation is dropped to 51.18%. The demand on Falgun was dropped to 88.34%. See the B.S. to A.D. calendar conversion table in (Fig. I). Some curve and graphs are published in www.nea.org.np..

The Fig. 61 shows the daily load curve of Nepal Electricity Authority, Day of ... Shrawan 2064 B.S. (see Fig. I). And the (Fig. 60 & 61) shows the breakdown of daily total energy generation including power cut, spill, and import. The Fig. 60 shows that within a day there is spill energy and power cut (load shedding). The Fig. 61 shows that there is capacity deficit in some hours. The Fig. 63 shows that the situation of capacity deficit runs Shrawan, Bhadra, Aswin, Kartik, Mangshir and Ashadh. And in Paush, Magh, Falgun, Chaitra, Baishakh and Jest, there was energy deficit situation (Fig.63). To meet the peak demand, peaking power station are built. These stations will be either multi fuel plant/ thermal plant/reservoir type of hydro plant. The targeted operations of these plants are few hours of a day to support the peak demands. The cost of average energy price increases, as the required capacity of peaking station increases (Fig.65).

The amount of electrical energy being fed into the grid must always match with the consumption. This varies not only from day to day, but also from minute to minute. As per demand/supply situation, starting-up and shutting-down operations of turbines/power stations/feeder must be brought in play. Beside this, power cut technique is applied if deficit is too high. Reserve margin electrical energy is required for emergencies. High reserve margin is waste of power that increases electrical energy prices. Too little reserve margin is disastrous, leading to blackouts and customer dissatisfaction. A significant imbalance could cease grid stability or terrible voltage fluctuation cause huge loss of property. Managing the actual reserve margin is highly complex. It is called "Utility Load Management'V'Demand Side Management (DSM)".

The demand side management is equally important as power generation. As electrical energy cannot store efficient way and to stabilized the grid, the generation and consumption should be matched. So the demand side management is a complex task.

By lowering the differences of peak load and off peak load, we can lower the cost of energy, capital investment to build peaking centers (Fig.65) and in other hand we can save environment too. Environmental Aspects (Global Warming):

As scientist notice the green house effect, the global warming is key issue to protect earth environment. The global average air temperature near the Earth's surface rose (0.74 ± 0.18 ⁰C ) (1.33 ± 0.32 ⁰F) during the 100 years period ending in 2005 via the greenhouse effect. Natural phenomena such as solar variation combined with volcanoes probably had a small warming effect. The green house gases are water vapor, carbon dioxide, methane, nitrous oxide, ozone.

Climate model projections summarized by the IPCC indicate that average global surface temperature will likely rise a further 1.1 to 6.4 ⁰C (2.0 to 11.5 ⁰F) during the 21st century. Increasing global temperature will cause sea level to rise, and is expected to increase the intensity of extreme weather events and to change the amount and pattern of precipitation. Other effects of global warming include changes in agricultural yields, trade routes, glacier retreat, species extinctions and increases in the ranges of disease vectors.

The emission of carbon dioxide to generate IkWh energy from coal is 0.940kg (940kg/MWh), oil-based plant is 0.698kg (698kg/MWh), diesel plant is 0.764kg (764kg/MWh), and natural gas is 0.581kg (581kg/MWh). Hence reducing the consumption by small quantity by every consumer and the proper utilization of energy will be great contribution to save environment.

The power provider applies planned rolling blackout or unplanned power cuts technique if energy deficit is higher than the peaking capacity (See Fig. 60 & Fig. 61). By analyzing above limitation, both environmental aspect and demand side management, to supply the energy as per consumers' demand and requirement is difficult/almost impossible and not justified. Even small contribution made (lowering consumption) by every consumer, the difficulty is manageable and make big difference. From Fig. 66, we can understand that by lowering 3.32% by every consumer, the power cut ( load shedding) would be avoided in fiscal year 2063/64B.S.

Electrical energy is a convenient form of transmitting clean energy which is widely used. Electrical energy cannot be stored in a highly efficient way; generation and consumption are therefore generally simultaneous, and work in a supply-demand manner.

Electrical energy is widely used because it is an extremely flexible form of energy. New verities of electrical equipments are being invented day by day. The consumers prefer electrical energy instead of using alternative source of energy. Hence, the application and demand of electrical energy is increasing rapidly.

The above Fig. 60 can elaborate the energy generation throughout the month. The most important remarkable fact is that within a day there is rolling power cut (Load shedding) and spill energy situation. This is because the energy cannot store efficient way and load shifting situation cannot create where the tariff rate is flat. All of the Hydro based power station are not capable to manage the situation arise like above with the conventional demand side management technique and available technology.

As the season changes, the time period of on- peak, mid -peak and off-peak will change. It is a big challenge to increase demand (load) at times of high production and low demand. Likewise, shifting the load from peak to mid/off peak is challenging.

The consumers can be classified in different group based on their energy demand hour and the nature of application. Some group of consumers need more energy in specific period of time so the demand jumps suddenly but the production of energy remains steady.

The main reason of peak hour is due to the domestic load, industrial load and other loads are coinciding. In present distribution system, all types of consumer are in same distribution line. So the separate supply for separate consumer group is not possible. Hence it is not possible to restrict all industrial loads in the time of peak hour. Where variable tariff rate are adopted by using TOD meter, some load will shift in low tariff period. In the Fig. 61 shows that the demand is almost double at 20 o'clock.

Due to the variable load demand, sometimes the energy deficit is too high and within a few hours interval of times, the same quantity of energy becomes excess. It is creating a huge challenge to the power provider to supply constant energy at consumers' required time as per their demand. Obviously, it is increasing the average price of electrical energy.

Public suffer due to load shedding during evening hours; it is because all the consumers' load demands coincide. A study shows that a 1% load shift in peak demand would result in saving of approx. 4% of electrical energy cost. The relation between price., demand, load shilling are shown in Fig. 65. Explanation of demand response effects on a quantity (Q) - price (P) graph. Under inelastic demand (Dl) extremely high price (Pl) may result on a strained electrical energy market. If demand response measures are employed the demand becomes more elastic (D2). A much lower price will result on the market (P2).

It is estimated that a 5% lowering of demand would result in a 50% price reduction during the peak hours of the California electrical energy crisis in 2000/2001. The market also becomes more resilient to intentional withdrawal of offers from the supply side.

The unauthorized and default consumers are consuming energy more than their requirements. The NEA data showed that in fiscal year 2063/64, the total system loss is about 24.94%. It is supposed that the theft fraction is about 15%. Whereas the energy shed is 3.32% (Fig 66). Hence the price and demand of energy is higher than real price and demand respectively. Necessary measures and control mechanism should be built.

To avoid/reduce the energy deficit/capacity deficit situation, different demand management techniques are applied. If these techniques cannot manage the deficit, the system enters in rolling power cuts (Load Shedding) to required number of feeders. Applied Solutions to avoid/reduce the ener2V deficit situation:

Consumer awareness Program: In response to peak load demand, power providers request consumers to reduce load in peak hours and some special schemes are also launched. Even though consumers are conscious to co operate to reduce their load consumption voluntarily in peak load period; technically they cannot calculate how much load they should reduce to meet the steady supply. A huge mass of consumer should be mobilized and it is very difficult task. In such situation excess cut down or less cut down will create imbalance in grid.

CFL / LED Lamps: By inspiring the consumer, to use low energy consuming lighting appliances like CFL/LED Lamps, high efficient motor and home appliances, power provider can lower the energy demand.

Separate single phase distribution System: To tackle energy deficit problem, a separate single phase transformers are being fixed and separate feeders are being setup in Goathans village, Western Maharastha, India. When the load decreases to less than 33 % (cut off 67% load), load shedding in the city is removed in the evening. The process is time taking and costly too. It is not the perfect solution and does not address the other associate challenges.

TOD Metering and Dual Tariff: To reduce load demand in peak hour, time of day (TOD) metering devices have been installed in some bulk users' premises. In this application, users have to pay high price at peak load period. As per this principle the consumer will use less energy in peak load period because of high price. Hence the bulk users will shift their load demand in low rate period. This principle does not effectively work if there is energy deficit because it can not restrict the consumer to consume more energy in peak load period. And the price is not the only one factor to inspire the consumers to shift their load in low energy demand period.

Brown out: To reduce the load demand the power providers deliberately lower the line voltage on the power grid. According to Ohm's law, power consumption of electrical equipments reduces as voltage reduces. The equipments' efficiency decreases as well. If line voltage lowered far enough, it causes damage to electric motors and other devices. The intensity and quality of light will decrease.

Timer Device: Installing the timer device, some load can shift from peak load to mid peak and off peak by avoiding the application of the equipments during the peak load period. Separate device is needed to each electrical appliance. On the other side, the pattern of actual deficit in the real time cannot be predicted correctly.

Ripple Control: Ripple control can be found to communicate between the power station and to the end users. It has been used in various parts of Europe. The power provider apply this system to control the street lights, power cut to heavy load users in peak hours, to update duel-rate tariffs to TOD metering device and it is also applied like PLC and SCADA to switch on and off to the power feeder. An idea was conceived to reduce the electrical energy price in the peak hour, thus motivating customers to shift the operation of electrical appliances into off peak hours. Therefore, duel-rate tariffs (high and low tariffs) were implemented, where the electrical energy price for small-scale consumer is not stable during the day. In order that consumers need not be concerned about the type of the electrical energy tariff currently used by them, utilities provider connects and disconnects electrical thermal appliances along with switching tariffs based on the adjustment of electrical installations for the thermal water treatment, accumulation or direct heating in the building, irrigation pumps i.e. the correctly interlocked electrical thermal appliances may be switched on only during the low tariff period. Thus the ripple control service provided by the utility/service provider is not feasible where the electrical energy rate is flat. In the time of energy deficit, if only shifting the industrial load from peak to mid/off peak is insufficient, the contribution of all the consumers is needed to avoid/reduce load shedding i.e. load limiting.

Inverter: Due to energy deficit, the power providers are applying power cuts technique to manage the deficits. And consumers are using inverter to backup energy to reduce the effect on their day to day work due to power cuts. The capital investment is high. The constant maintenance fee, normally life of batters is 2year, batteries are environment hazardous substance. So, few consumers are using it. And the efficiency of such device is about 90%. The loss of energy and storing the energy is causing negative effect to rest of consumers. This means the power cuts period will increases i.e. negative effect in energy deficit situation. The storing energy will create positive effect only if there is capacity deficit.

Rolling Power Cuts (Load Shedding): To manage energy deficit, Power cut (load shedding) technique is commonly applied at present which is creating a numerous problems rather than solutions, i.e. Public facility operations like hospitals, government office, publications, electronic media, ISPs, Banks, students etc. are directly affecting. Security problems are significantly increasing due to load shedding. Besides this, it increases cost of energy because the excess energy cannot be properly utilized during the load shedding period as well. But there is no other available option (technology).

New logics/ Justification:

The consumers can be classified as per their demand time and area of application of energy. Hence the need of energy should be prioritized i.e. Public facility operations (hospitals, government office, publications, electronic media, ISPs, banks, street light), hotels, house hold, industry etc. Further, the consumers should prioritize their own application of the energy too i.e. first at least basic light then other application depending upon the priority set by the electrical energy providers. Priority order should be made for different consumer group. Hence the distribution should make as per priority basis when the energy is deficit.

The cause of peak demand is due to all loads (industrial load, domestic load and other load) are coinciding. Hence within a day there is spill energy and energy deficit situation. And it is difficult to the power provider to restrict the industry to consume the energy or, to shift their load where the energy is available. Load Shifting solution is effective in capacity deficit situation. If load is shifted into off peak/mid peak, the spill energy will use and the less peaking station is required. Even in energy deficit; this technique will help to lower the peaking stations. Hence the cost of electrical energy will lower (Fig.65).

In the electrical energy supply system, a situation should be created in such a way that the consumers seek other source of energy instead of electrical energy to fulfill rest of their needs if the energy is deficit. It will reduce the dependence on electrical energy.

The above logic is not totally applied because the present supply system is feeder-wise, where all types of consumers are mixed-up under the same feeder. Hence the priority based supply is not possible in the existing system.

The consumption fluctuates from minute to minute. Reserve margin electrical energy is required to stabilize the grids for emergencies. As per demand/supply situation, starting-up and shutting-down operations of turbines/ power stations/feeder must be brought in play. Reserve margin electrical energy is required for emergencies. High reserve margin is waste of power that increases electrical energy prices. Too little reserve margin is disastrous, leading to blackouts and customer dissatisfaction. A significant imbalance could cease grid stability or terrible voltage fluctuation cause huge loss of property. Even by utilizing reserve margin, if energy is deficit, the power provider has remains only option of power cut of number of feeder.

Hence, besides available technology the power provider should have a real time option to lower the supply capacity to its consumers proportionately instead of power cut and vice versa. It can reduce the consumption of energy of its consumers at that period and avoid the load shedding (power cuts). At the time of energy deficit, every consumer should contribute in to the grid to avoid the power cut by lowering their consumption capacity. Multiple paths supply system where the paths can be remotely controlled by energy provider, will be a better real time technique in energy demand side management. The power provider can open the installed capacity path when the energy is sufficient and if the energy is insufficient the power providers can lower the supply capacity of energy to consumers by changing the lower capacity paths to reduce the consumption. As per available capacity every consumer can set their own priority uses. It makes more harmony in electrical energy distribution system and reduces the system loss, reserve margin. The leakage and theft of energy reducing mechanism should be built.

SUMMARY OF THE INVENTION

The power relay / solid state relay gives alternate two paths. One is closed while the other is open. If the relay is activated, the close path changes to open path and vice versa. It is used to change the electrical path and can use as a switch if one point kept dry. If miniature circuit breaker (MCBs) or molded case circuit breaker (MCCBs) having different capacities are connected in series on each path, two different paths having different capacity will be created. The contactor and changeover switch, air circuit breaker (ACB), vacuum circuit breaker (VCB) are a type of switch which can connect or disconnect the energy flow in circuits. Connecting two or more relay /contactor /automatic changeover switch/ ACB/VCB in series or parallel or mix (series and parallel), we can create multiple paths. When MCBs or MCCBs of different or same capacities are connected in each path, multiple parallel electrical supply paths (some close and some open) having different capacities in the circuit is created. A load limiter receiver (LLR) is a device that receives and executes the coded command transmitted by corresponding transmitter. The LLR is connected with each relay/contactor/change over switch/ ACB/VCB and buzzer. It executes the corresponding relay/contactor/automatic changeover switch/ACB/VCB and creates new electrical supply path(s).The combined system described as above comprising of receiver, relay/contactor/automatic changeover switch/ACB/VCB, buzzer and MCBs/ MCCBs of different or same capacities, as shown in Fig. 1 to Fig. 55 is termed as " "Load Limiter" ". The "Load Limiter" may be single phase (Fig.1-36) and may be three phase (Fig.37-55) or full access three phase and limit mode single phase. The relay/contactor/MCB/MCCB is made for single phase and three phase. The changeover switch, ACB, VCB is there phase. Using the single phase switching device we can make single phase "Load Limiter" and by using three phase device we can make three phases "Load Limiter".

The "Load Limiter" device, fitted at the consumers' premises in series to the metering device/power line transformer is controlled and operated by wired or wireless communication channels i.e. radio frequency (RF), power line communication (PLC), Pagers, General Pocket Radio Service (GPRS), Global System Of Mobile (GSM), Code Division Multiple Access (CDMA), Timed Division Multiple Access (TDMA), Frequency Modulation (FM), UHF, VHF, Signals etc (hereinafter called "Communication Channels"). Such transmitters of communication channels are under the control of the power providers. Depending upon the electrical energy generation and demand, the power provider activates the corresponding clusters of consumer by switching on the "Load Limiter" through the transmitter to change the electrical energy supply capacities.

The address i.e. identification code (ID), is coded into the LLR. Different IDs can code in a receiver. One ID is used as its own unique identification code and rest are used for group/ sub group identification. Within a group/sub group, the address is same in LLR used. Different group will have different ID. Hence the coded message transmitted to IDl will activate the single LLR and the coded message transmitted to group ID will activate the corresponding LLRs of its group. To cover more conditions, ID2, ID3... are use for group and sub groups.

Another way to code receiver is frequency wise, in each group have separate frequency. Hence group wise command is possible.

BRIEF DESCRIPTION OF THE DRAWINGS

Figs. 1-55 respectively shows a configuration of a load limiter according to an embodiment of the present invention;

Fig. 56 shows the network between a central computer and several station computers;

Fig. 57 shows connection relationship with in a central control room and station transmitter room;

Fig. 58 shows a table of consumers group;

Fig. 59 shows incorporation of the load limiter of the present invention and the present grid system; Fig. 60 illustrates the energy generation throughout a month;

Fig. 61 shows the daily load curve of Nepal Electricity Authority;

Fig. 62 shows the energy curves of spill energy and total of load shedding, import and thermal in fiscal year 2063/64B.S;

Fig. 63 shows the energy curves of spill energy, load shedding, thermal and import in fiscal year 2063/64B.S;

Fig. 64 shows total demand curve of the electrical energy and the generation curves of the electrical energy in fiscal year 2063/64B.S;

Fig. 65 illustrates the relation between price, demand and load shifting;

Fig. 66 shows the formation parts of the electrical energy and their proportions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Fig.58 shows the table of consumers group. The formation of consumers group should be according to their priority and usage. The number of group/sub group could be determined as per power provider's need.

As shown in Fig. 57 an antenna of transmitter is connected with its transmitter, the transmitter is connected with a control device and the control device is connected with computer. This type of connection is set up in central control room and station transmitter room. The network between central computer and the stations computer are shown in Fig. 56. The schedule will transmit from server computer situated in central control room to its client computers. The client computer sends the coded message to control device then encoding the message to its format and the control device forwards it to the transmitter. Then it transmits the signals.

The figure (1-55) show the configuration of load limiter. In each figure, there is a table (Table 1 -Table 55) to show the formation of paths and its capacity. Table 1 is for Fig.1 and so on.

The few combinations of "Load Limiters" are shown in Figl-55. The "Load Limiters" are both single phase and three phases. The Fig.l, 37 & 40 are two paths "Load Limiter"; whereas Fig. 2, 3, 4, 21, 38, 39, 48 are three path; Fig. 5 ,6 ,7 ,10 ,12,15,18,22, 23, 41, 42,44, 45, 49, 50 are four paths, Fig. 8, 9, 11, 13, 14, 16, 17, 19, 20, 24, 46, 47,54,55 are five paths; Fig. 25, 26 ,43 are six paths; Fig. 27,30, 33, 51, 52, 53 are eight paths; Fig. 28, 29,31, 32,34, 35, 36 are nine paths. Using more relay\contactor\changeover switch\ACB\VCB and MCCBMVICB we can create more paths "Load Limiter".

The receiver have more than one address(ID), the same group /sub group will have same address(ID). Hence the signal transmitted to targeted group is possible.

In Fig.59 it is shown that the present grid system and easy incorporation of our technology without any alteration in present distribution system. The energy generations by different power stations/turbines enter in to the grid at high voltage using step up transformer. At substation, the voltage is lower by step down transformer. Then the energy sends to distribution line through feeder switch. The voltage again lower by using steps down transformer and enter in low voltage distribution line. Then the supply connected to consumers. The link between load dispatch center and feeder/station is by communication channels. They pass information each other. As energy deficit situation arises, the load dispatch center command to switch off the 'feeder switch' to shed some load by remote signal or order the feeder people to switch off. And the consumers under that feeder enter into black out.

Our concept is to connect the load limiter device in series with electric meter in consumer premises. The device have receiver having more than one address (ID). The same group of consumers spread in different feeders has same address (ID). We can send the command to targeted group by sending coded message. Hence multi path and priority based electrical energy supply system is possible without any alteration in present distribution system.

Let us see the circuit of Fig.6, the Load Limiter have four paths (see the table 6 in Fig. 6, wherein "NA" means not applicable.). When power provider requires lowering the supply, they prepare a message to alert the consumer group in software for a specific period of time and transmit it. The transmitted coded message received by the corresponding LLR of group and switch on the buzzer and beep it. After specific time period it stops beeping. Then they will transmit another coded message for the group choosing the paths. The LLR will receive its coded message and execute the corresponding relay/contactor/change over switch. If power provider sends the coded message Rlayl (Rl) on, this action will disconnect the power supply and terminate the service. If the message Rl off & R2 on. the path will be through MCB (Ml) and its capacity will be Ml . The M stands for MCB/MCCB. Likewise Rl off. R2 on & R3 off will open the path M2 and Rl off. R2 on & R3 on will open the path M3. The capacity of Ml, M2 & M3 is different, so different capacity multiple path is created. In figures, the 'C stands for contactor and 'CS' for change over switch\ACB\VCB.

The buzzer is place to alert the consumer about the limit mode. As buzzer beep in different tone, consumers know the supply capacities. But still they don't know the duration of limit. To inform them about the group, running capacity and duration will have following option: a. The information can broadcast by FM/Radio/TV b. Keeping the information in web side. c. The most effective and economy way will be to establish own radio station by power provider, as limit mode runs to some group of consumer, they transmit the information by their station. They transmit group code/name, capacity (L1/L2/L3..), duration continuously. While alert buzzer beeping, the consumer can tune the radio and can receive the information. Then the consumer can resize their load and they can plan their other application. d. As we have a transmitter in the station and receiver in load limiter device, a small screen can be connected to LLR, when a coded message is transmitted while switching, the information will display in LCD. Small cost will increase, as we have all infrastructures (Radio Frequency Transmitter and Receivers). e. By sending sms to its consumer, we can provide information about limit mode. We can create such feature in software. f. In each path one LED indicator cab is connected, to indicate the current supply mode.

Operating software is developed. It helps to control the "Load Limiter" dynamically. In the software we can select the group, station (city), its paths (i.e. Full, cut, Beep, limit 1, Limit2... Limit n), the limit mode period i.e. 'start time' and 'end time'. After preparation of work schedule, the central computer will transmit it to its corresponding station computer. The station computer will transmit the command to its control device, the control device forwards the coded message to transmitter and transmitter transmits it. The receiver situated in load limiter will receive its own message and execute it.

Sending the "beep switch on" coded message of a group will alert the corresponding consumer group that the supply is going in to limit mode so that they will resize their consumption to match the limit mode. The signals transmitted by central/ station control room transmitters will be received by the corresponding receiver of "Load Limiter" and activates the alert bell in specified time period. A second coded message will send by computer selecting the path of limiter to switch over to limit mode (Fig 1 - 55). The corresponding LLR of the "Load Limiter" will execute the relay/contactor/automatic changeover switch/ ACB/VCB to change the path of electrical energy supply at the consumers' energy meter box/power line transformer. At the same time beep tone will ring at certain interval of time to aware that they are in limit mode. If the consumers do not reduce the load consumption matching with limit mode, the MCB(s)/MCCB(s) (Fig 1 - 55) will trip automatically. Then the consumer can re-activate the supply after reducing load consumption within the limit mode and switch on the MCB(s)/MCCB(s) (Fig 1-55). The limit mode capacity is derived by the negotiation between the power provider and consumer by justifying the essential load requirement calculation for peak load period or by analyzing the billing history or by installed capacity or combination of them. When the system is run on limit mode, the running work schedule will display on computer monitor of the control room and station control room. As it reaches the end time, the computer will send the command of full access. At the same time the beep will stop to beep. Then consumer will understand that they are not in limit mode.

To terminate the supply of defaulter consumer, the station manager can send a command and disconnect the supply. As we want to re connect it, one coded message will enough.

When the supply/ demand data suggests removing the load limit mode for all groups or some group, power provider send coded message to remove the limit mode for the specific consumer group or for all. So the limit mode can be deactivated sending the off signals.

Thus, this new invention provides multiple electrical energy paths on electrical energy meter box controlled by communication channel based system which is an improvement in the present single path electrical energy supply system. One is normal consumption which allows full authority usage and others are limited usage (lower capacities) for peak load period or power crisis. The consumers can be classified into different groups irrespective of the single feeder without changing the existing distribution system. So that the priority basis supply become possible. The device "Load Limiter" simply can be installed within the energy meter box which does not need extra wiring and extra distribution line from central control/feeder based on the demand forecast calculated on the basis of supply/demand data. The power provider can change the path of electrical energy in every electrical energy meter box within five minutes (or less) after sending alert signal. The system regulates through wired/wireless signal. While the consumers are in limit mode, an alert signal will be received by consumer on continuous basis for a specified time interval.

Claims

WHAT IS CLAIMED IS:

1. A load limiter for changing electrical energy supply capacity for a consumer, comprising: a plurality of paths of electrical energy supply with different capacities; at least one relay or contactor or automatic changeover switch or air circuit breaker or vacuum circuit breaker; and a receiver connected with the at least one relay or contactor or automatic changeover switch or air circuit breaker or vacuum circuit breaker and adapted for receiving controlling signals and selecting the paths according to the controlling signals.

2. The load limiter as claimed in claim 1, wherein the paths comprise at least two miniature circuit breakers or molded case circuit breakers.

3. The load limiter as claimed in claim 2 , wherein the relays are connected in series or parallel or mixed to create multiple paths.

4. The load limiter as claimed in claim 2, wherein the relay is either Single Pole or Double Pole or Triple Pole.

5. The load limiter as claimed in claim 2, wherein the contactors are connected in series or parallel or mixed to create multiple paths.

6. The load limiter as claimed in claim 5, wherein the contactor is connected to make single phase or three phase multiple path.

7. The load limiter as claimed in claim 2, wherein the contactors and the relays are connected in series or parallel or mixed to make single or three phase multiple paths.

8. The load limiter as claimed in claim 2 wherein the automatic changeover switches or air circuit breakers or vacuum circuit breakers are connected in series or parallel or mixed to create multiple paths.

9. The load limiter as claimed in claim 2, wherein the automatic changeover switches or air circuit breakers or vacuum circuit breakers and the relays are connected in series or parallel or mixed to create multiple paths.

10. The load limiter as claimed in claim 2, wherein the automatic changeover switches or air circuit breakers or vacuum circuit breakers and the contactors are connected in series or parallel or mixed to create multiple paths.

11. The load limiter as claimed in claim 2, wherein the automatic changeover switches or air circuit breakers or vacuum circuit breakers, the relays and the contactors are connected in series or parallel or mixed to create multiple paths.

12. The load limiter as claimed in claim 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein the automatic changeover switches or air circuit breakers or vacuum circuit breakers, the relays and the contactors are same or different in capacities.

13. The load limiter as claimed in claim 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein the configurations of the relay, the contactor, the automatic changeover switch, air circuit breaker and vacuum circuit breaker are normally open or normally close mode of the device or mix.

14. The load limiter as claimed in claim 2, wherein the miniature circuit breakers or the molded case circuit breakers are connected in series in each path to make different capacity multiple paths.

15. The load limiter as claimed in claim 2 and 13, wherein the miniature circuit breaker and the molded case circuit breaker are single pole, double pole, triple pole or four pole.

16. The load limiter as claimed in claim 2, wherein the receiver is linked in each relay, contactor, automatic changeover switch, air circuit breaker and vacuum circuit breaker in the load limiter to execute the command transmitted by transmitter to select the paths.

17. The load limiter as claimed in claim 2, wherein the receiver is linked with a buzzer to alert the consumer about the pre alert and limit mode by different tone.

18. The load limiter as claimed in claim 2, wherein the receiver is linked with LED light to indicate the current supply path as one LED light is connected in each path.

19. The load limiter as claimed in claim 2, wherein the receiver is linked with LED display to display the information transmitted by the transmitter about the current path and estimated period of limit mode.

20. The load limiter as claimed in claim 1 or 2, wherein the load limiter is connected with different consumption groups formed by the installed capacities or by energy consumption record or by nature of application.

21. The load limiter as claimed in claim 20, therein the consumption group is divided into sub groups.

22. The load limiter as claimed in claim 2 or 21, wherein the receiver has at least one address.

23. The load limiter as claimed in claim 22, wherein the receiver has more than one address, one of the address is used for itself and others are used for the groups and the sub groups.

24. The load limiter as claimed in claim 23, wherein the receiver has same group address for same group and same sub group address for same sub group.

25. The load limiter as claimed in claim 24, wherein the receiver of the same group or sub group receives the signal transmitted to the group or the sub group by station transmitter and executes the command.

26. The load limiter as claimed in claim 1, wherein the load limiter is connected in series with consumers' energy metering device.

27. The load limiter as claimed in claim 1, wherein the load limiter is connected in series with a transformer.

28. The load limiter as claimed in claim 1, wherein the load limiter is linked with wired or wireless communication channels.

29. The load limiter as claimed in claim 28, wherein the communication channel is radio frequency, power line communication, Pagers, General Pocket Radio Service, Global System Of Mobile, Code Division Multiple Access, Timed Division Multiple Access, Frequency Modulation, UltraHigh Frequency, Very High Frequency Signals.

30. The load limiter as claimed in claim 28 wherein the communication channel is operated by computer software.

31. The load limiter as claimed in claim 30, wherein the computer software is connected with the communication channel and the command is transmitted through transmitter signals to select different paths.

32. The load limiter as claimed in claim 30 or 31, the computer software codes the receivers, dispatches the command for executing the corresponding switch, schedules the message to be delivered to the receivers, calculates the load to be reduced, and accounts information.

33. The load limiter as claimed in claim 28, wherein two or more parallel paths are created by switching over of the relay, contactor, automatic changeover switches, air circuit breaker or vacuum circuit breaker using the communication channels.

34. The load limiter as claimed in claim 28, wherein the communication channels are used for networking between different city, transmitter and consumers to change the electrical energy supply capacity.