JPWO2017022339A1 - Power system - Google Patents

Abstract

It is an object of the present invention to provide a power supply system that can solve various problems caused by transient characteristics of a large-capacity auxiliary machine. A power supply system including a transformer connected to an AC power source, a bus provided on the secondary side of the transformer, a load connected to the bus via a circuit breaker, and a large-capacity capacitor for holding DC power; A power conditioning system that regulates the power of the capacitor and supplies the load to the load. A power supply system that adjusts and supplies power to a load.

Description

  The present invention relates to a power supply system in various plants, and more particularly to a power supply system for supplying power from an AC power supply to various devices in the plant via a substation facility.

  As an example of various plants for business and industrial use, for example, in a thermal power plant, the power generated by a generator (synchronous generator or induction generator) is connected to an AC system via a substation facility to supply power. Yes. In addition, an in-house substation facility is configured as a part of the substation facility, and power from a generator or an AC system is supplied to various auxiliary machines in the power plant to maintain various functions of the power plant. Alternatively, in the case of a plant that does not have a generator, power is supplied from the AC power supply to various devices in the plant via the transformer facility.

  The power supply system that is the subject of the present invention is based on the above concept, and the auxiliary equipment includes one that is used in normal operation of the plant, or one that is operated in the event of power loss such as a generator or an AC system. In addition, these auxiliary machines include an AC drive type and a DC drive type.

  With regard to such power supply systems, the current knowledge is that AC and DC configurations that have been well-established based on the experience of thermal power plants and other power plants over many years (UPS has the meaning of hybridizing both here, but includes functions) However, this is a common recognition in the power generation / power system industry, and many examples of configurations have already been known for such power supply systems.

  In addition, these power supply systems are equipped with emergency power supplies such as diesel generators and gas turbine generators for the purpose of securing power supplies for auxiliary equipment in an emergency, or with direct current power supplies such as storage batteries. Auxiliary power supply is secured. However, when possessing these facilities with sufficient capacity to cover the full load in an emergency, there are problems such as long start-up time until the start of the diesel generator and naturally limiting the capacity of the storage battery. .

  On the other hand, in recent years, the technology of the large-capacity capacitor power supply facility disclosed in Patent Document 1 has attracted attention as a facility capable of supplying power to both the AC auxiliary device and the DC auxiliary device. The large-capacity capacitor power supply equipment constitutes a power storage equipment in combination with, for example, a LIB (lithium ion battery), stores electric power therein, and through a power conditioning system PCS having a power conversion function, AC auxiliary equipment or DC auxiliary equipment An appropriate form of power can be supplied.

International Publication Number WO2013 / 145002 / A1

  As a plant, for example, in the operation of a generator in a power plant, there is a turbine that drives it, and the auxiliary machinery group is appropriately operated around the main engine, so that the function of the power generation system as a whole is demonstrated. Yes.

  Incidentally, in general, many of the electrical loads of the auxiliary machines are of the AC power source type, and some of them have operational characteristics that perform their functions only during a part of the operation period of the entire operation period. The function being exhibited in a part of the operation period is, for example, an auxiliary machine that requires intermittent operation necessary only when starting the gas turbine. These auxiliary machines are required to have a relatively large load capacity only during a limited period, and the capacity during other periods is rarely regarded as a problem. In short, short-time rating is a problem, and it has a capacity far exceeding the normal rating. A typical example of an operational characteristic that performs its function only during some of these operating periods is often an auxiliary machine as an emergency facility described above.

These auxiliary machines may impose restrictions on power supply facilities due to their short-time rated characteristics.
For example, various auxiliary machines are collected in appropriate units and supplied with power from a transformer. In this case, if the auxiliary machine is composed only of an auxiliary machine intended for normal operation, the capacity of the transformer can be determined in consideration of the total rated capacity of all auxiliary machines. However, in the case of including an auxiliary machine having an operation characteristic that performs its function only during a part of the operation period, it is determined in consideration of the magnitude of the large-capacity load in a short time at the start-up.

  Specifically, there is a voltage drop phenomenon of the power supply bus that occurs when a large-capacity auxiliary machine (generally an induction motor) is started, and there is a risk of interrupting the lower limit of the allowable operating voltage range of other electrical loads during bus operation. is there. This usually imposes restrictions on the selection range of the impedance of the transformer constituting the upper power supply system. This means that the capacity of the transformer should be increased to achieve the transient conditions. In addition, in the bus configuration of important on-site power sources of the power plant, the power supply line may be switched between multiple buses, so that the voltage and phase are not adversely affected by the operation status of the load on the operation continuation side. It is necessary that the matching conditions be established in advance.

  Common to the cases as described above is an in-house dynamic disturbance (due to the introduction of a large-capacity auxiliary machine) that occurs in the middle of stable operation. As a countermeasure against this, although the design as the current state of the art is naturally made, it is merely made as a restriction on specification determination. If dynamic disturbance is assumed, it has already been established as a general wisdom of the technical contents to increase the capacity of the transformer and allow for a margin. It is not something that goes back and looks back.

  Under this situation recognition, in order to pursue a more rational design specification, the recognition is fixed to common sense, and the current situation is that it has not been highlighted and has to be given up unconsciously.

  On the other hand, in terms of efforts to reduce the discharge of load substances from the viewpoint of the global environmental load in recent years, in conventional thermal power plants, it is a scenario story of a mission that mainly contributes to improving the combustion efficiency. The power generation industry is also required to improve the overall efficiency of the actual situation by combining it with a new renewable energy system (combined).

  From these viewpoints, when the power supply system is applied to various plants, it is desired that the power supply system can cope with problems required for various plants. For example, while various plants are required to improve efficiency from the environmental aspect, it is desirable that the power supply system itself can contribute to efficiency improvement.

  In view of the above, an object of the present invention is to provide a power supply system that can solve various problems caused by the transient characteristics of a large-capacity auxiliary machine.

  From the above, in the present invention, a power supply system including a transformer connected to an AC power source, a bus provided on the secondary side of the transformer, and a load connected to the bus via a circuit breaker, Including a large-capacity capacitor that holds power and a power conditioning system that regulates the power of the capacitor and supplies the load to the load. The power conditioning system includes support power that is determined by using the start-up characteristics of the load when the circuit breaker is turned on. Therefore, the power supply system is characterized in that the electric power from the large-capacity capacitor is adjusted and supplied to the load.

  The present invention also includes first and second transformers connected to an AC power source, first and second busbars connected to secondary sides of the first and second transformers, and first and second transformers, respectively. A power supply system having a tie line between buses connected via a circuit breaker for connection between the two buses and a load connected to the first and second buses via a circuit breaker, and is a large power source system that holds DC power And a power conditioning system that regulates the power of the capacitor and supplies the load to the load. The power conditioning system is connected to the tie line between the buses, and the first and second buses are connected when the connection breaker is turned on. The power supply system is characterized in that it supplies power with adjusted voltage and frequency / phase of each phase.

  According to the present invention, in the system / specification of the power source configuration of the thermal power generation system and other power generation systems that agree with the public opinion that it has already been refined and established, further rationalization of facility capacity (specification), dynamic or transient The effects of reducing costs by relaxing constraints on equipment specifications related to safe operation, realizing stable dynamic transitions by improving the fluctuation status associated with transient phenomena, and Since energy sources can be allocated from natural energy, it is an effective solution in terms of improving the overall plant efficiency and responding to social issues such as low carbon.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

The figure which shows the outline | summary of the power supply equipment which concerns on this invention. The graph which shows time transitions, such as the electric power which electric power supply lines PA and PB give at the time of starting of the electric motor M in the in-house power supply equipment 100 of FIG. The figure which shows the structure of the control apparatus 10 of the power conditioning system PCS which enables scheduled harmonization control. The flowchart which shows a series of processing content in the control apparatus 10 of power conditioning system PCS. The figure which shows switching of the electric power supply system in a power supply bus-line. The figure explaining the idea of deviation vector cancellation. The figure which shows the transient characteristic in the case of a pump load with a short starting time. The figure which shows the transient characteristic in the case of a fan load with a long starting time. The figure which showed the example of the conventional Metakura M / C. The figure which showed the example of the metakura M / C in this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  An outline of a power supply facility according to the present invention will be described with reference to FIG. In FIG. 1, reference numeral 100 denotes, for example, an in-house power supply facility of a power plant, which is connected from an external AC power source G to an AC bus BUS via a power receiving transformer Tr, and from the AC bus BUS to a load M such as an electric motor as an auxiliary machine. Power is being supplied. The external AC power source is a generator inside the power plant or a generator outside the power plant via an AC system.

  In FIG. 1, since the main purpose is to explain the concept of the present invention, the configuration of the power supply equipment is shown in a simplified manner, but actually, it has a more complicated configuration. For example, an external AC power source connected to the on-site power supply facility of a power plant can be connected to multiple power sources from different systems, and the multiple power sources can be selected and connected as appropriate by inter-bus connection lines, and the transformer has different voltages. In many cases, a plurality of loads M such as electric motors that are auxiliary machines are connected to a single transformer. These devices and buses are connected so as to be turned on and off by a circuit breaker CB on the connection line.

  The description up to this point for the in-house power supply facility 100 of the power plant in FIG. 1 has the same configuration as that of the conventional in-house power supply facility. However, in the present invention, a large-capacity capacitor 104 is additionally installed, and DC / AC conversion is performed. It is connected to the AC bus BUS via a power conditioning system PCS and a circuit breaker CBP.

  In the present invention, a large capacity capacitor 104 derived from an additional DC power source and its DC / AC converter (power conditioning system PCS) are combined with a standard power plant in-house power source configuration form as the capacitor. In order to make use of the instantaneous performance, the power assist or the shock mitigation is performed according to the dynamic or transitional state change of electricity.

The directions of arrows indicated by symbols PA and PB in FIG. 1 indicate the direction and direction of power flow.
PA is a power supply line by a normal, original power supply system (external AC power supply G-receiving transformer Tr-AC bus BUS-breaker CB-load M), and PB is characteristic of the present invention. The figure shows a new power supply line by an additional power supply system (large-capacity capacitor 104-power conditioning system PCS-breaker CBP-AC bus BUS-load M). Although not shown in this figure, the large-capacity capacitor 104 can be charged from the bus BUS, but it is assumed here that the generated charge is stored by external renewable energy. A charging system applying the atmospheric electric field fluctuation described in Document 1 is assumed.

  In FIG. 1 showing the present invention, the power supply line PB is intended to send transient reactive power when the motor M is started up, and the reactive power from the power supply line PA in a stable state after startup. Is intended to be sent out. In other words, power is supplied also from the power supply line PB at the start-up transition (all may be supplied from the power supply line PB or partly supplied), and power is supplied from the power supply line PA during stable operation.

  This eliminates the need to set the equipment capacity of the equipment (such as the power receiving transformer Tr) that constitutes the power supply line PA in accordance with the peak load at the time of transient of the electric motor that is the load, and configures the power supply line PA. Can be set in accordance with the steady-state load of the electric motor as a load, and the equipment capacity can be greatly reduced.

  Looking at the power supply line PB from the power supply line PA, although it is power rescue from a different system, the control accuracy of the power conditioning system PCS is applied that has been sufficiently improved. It is not limited to connecting them in a uniform manner, but gives detailed designation of active power and reactive power every moment. In this case, the known data of the starting characteristic curve of the electric motor M is required in advance. However, as the electric motor characteristics, specific conditions such as design characteristics and actual machine test characteristics are grasped in advance by the control side of the power conditioning system PCS. It shall be.

  Here, the time required for starting up the electric motor M is generally a short time, and as a source of power for compensation therefor, a configuration is adopted in which power is supplied from the large-capacity capacitor 104 having high instantaneous characteristics.

  To express the above concept in an easy-to-understand manner, it will be referred to as electric power P / Q assist by “scheduled harmony control”.

  FIG. 2 is a graph showing the time transition of the power supplied by the power supply lines PA and PB when the electric motor M is started in the in-house power supply facility 100 of FIG. First, graph a is a current characteristic at the time of start-up of the electric motor M. The horizontal axis indicates time t, and the vertical axis indicates load current i. According to this graph, the load current i of the electric motor M increases to about 10 times (10 pu) of the rated current immediately after startup, then starts to decrease, and stabilizes at the rated current (1 pu) after several seconds to several tens of seconds.

  Graph a captures the starting characteristics of the motor from the viewpoint of load current, and graphs b and c show this divided into active power P and reactive power Q. The active power P in the graph b gradually increases to the rated power (1 pu) during the transition, but the reactive power Q in the graph c shows the same tendency as the load current i. That is, the reactive power Q rises and then falls until it substantially exceeds the rated reactive power immediately after startup, and stabilizes at the rated reactive power (1 pu) after several seconds to several tens of seconds.

  The relationship between the load current i, the active power P, and the reactive power Q is as shown in graphs a, b, and c. Conventionally, the active power P and the reactive power Q are borne and supplied only by the power supply line PA. In the present invention, the active power P and the reactive power Q are borne and supplied by the cooperation of the power supply line PA and the power supply line PB.

  Specific examples of burden coordination are shown in graphs d and e. In the graph d showing an example of the burden of the active power P, in the transient state, the load ratio between the power supply line PA and the power supply line PB is changed and increased to the rated active power (1 pu) to reach the rated active power (1 pu). After that, the burden ratio of the power supply line PB is set to zero, and the entire amount is paid by the power supply line PA.

  In the graph e showing an example of the burden of the reactive power Q, the reactive power Q is supplied by both the power supply line PA and the power supply line PB in the transient state, but most of the transient increase is performed from the power supply line PB. The burden of the reactive power Q from the power supply line PA is preferably suppressed to the extent that it increases according to the same gradual increasing tendency as the active power P. After stabilization to the rated reactive power, the load ratio of the power supply line PB is set to zero, and the entire amount is paid by the power supply line PA.

  According to the load ratio of the active power P and the reactive power Q at the time of start-up, the load content in the power supply line PA is determined by the rated active power and the rated reactive power of the motor M that is a load. As a result, the amount of power flowing through the power supply line PA can be reduced. In particular, the amount of current required to supply reactive power at startup is greatly reduced, so that the power supply line PA The internal voltage drop in the illustrated in-house transformer Tr, which is the upper power supply, is reduced. This acts in the direction of widening the selection range for the transformer impedance that determines the bus voltage drop, which means that a more economical transformer can be selected.

  The concept of the above-described scheduled harmonization control is summarized as follows. First, when supplying power to the load M in the graph a of FIG. 2, for example, a large starting (starting) current flows during starting. This is, for example, experienced by a full voltage starting method (DOL Start: Direct On Line Start).

  Next, when graph a in FIG. 2 is expressed by changes in active power P and reactive power Q, for example, graphs b and c in FIG. 2 are obtained. It is known that the active power P and reactive power Q characteristics are characterized by large changes in the reactive power Q, and it is known to be accurate from past design results of the same type in production tests and field tests. The characteristics are well reproducible. The start-up characteristics of the active power P and reactive power Q characteristics for the load M can be grasped in advance for each of a plurality of auxiliary machines at the preliminary examination stage of the equipment, and information is stored in the control device of the power conditioning system PCS. Is held.

  Therefore, in the present invention, as shown in the graphs d and e of FIG. 2, the sharing ratio of the active power P and the reactive power Q is determined, and the PA and PB are obtained, and are shown in the description of the power flow at the top of FIG. Thus, the required power of the electric motor M is realized by the synthesis of PA + PB.

  FIG. 3 discusses the control concept in the above-described power supply line combination technique and, when viewed in more detail, in the power supply lines PA and PB, discusses the relationship between the preceding, following, or master and follow of the control operation. It is a thing.

  Here, the power supply timing of the power supply line PB is executed in advance of the power supply timing of the power supply line PA. Basically, the power supply line PB is a master and the power supply line PA is placed in a follow-up position. The background idea is to reduce the equipment capacity of the devices constituting the power supply line PA without excessively supplying power from the power supply line PA.

  In general, there may be an intervening control mechanism in the relationship between the power source and the electric motor M as a load. However, as long as a predetermined voltage is applied, the power movement operation (power consumption) proceeds. However, according to the present invention, the characteristics of the motor at the time of starting, the load characteristics in a steady state that is not transient, the load characteristics in the steady state, the dynamic power compensation, and the power supply line PB on the side that knows its own power amount and control performance are also known. The idea of performing control with primed current and power is adopted. Here, when the relationship between the master and the follow is reversed, the state change of the power supply line PA proceeds first, so that the concept of overall harmony becomes a follow-up form and is disadvantageous in terms of accuracy. It is because it thinks that it becomes.

  FIG. 3 illustrates a configuration of the control device 10 of the power conditioning system PCS that enables the scheduled harmony control. The control device 10 of the power conditioning system PCS is generally configured by a computer system, and the storage unit 11 has the above-described active power P and reactive power Q characteristics obtained for each auxiliary machine for a plurality of motors M. The starting characteristics are stored. The storage unit 11 also stores information on the line configuration of the in-house power source of the power plant.

  FIG. 7 shows an example of the starting characteristic of the reactive power Q characteristic (expressed as a load current). FIG. 7A shows a transient characteristic in the case of a pump load with a short start-up time, and is 8.0 in a short time. It increases to (pu) and then quickly decreases to the rated current. It is characterized by a large maximum value and a relatively short transition time. FIG. 7B shows the transient characteristics in the case of a fan load with a long start-up time, which gradually increases to about 5.5 (pu) over time and then gradually decreases to the rated current. It is characterized by a small maximum value and a relatively long transition time. The start-up characteristics for each of these auxiliary machines are stored as information on maximum values, duration information, or information including mapping information at the time of transition, which includes them.

  The input unit 13 obtains information on a closing instruction of the circuit breaker CB for connecting to the power sources of at least a plurality of electric motors M. The instruction to turn on the circuit breaker CB identifies the motor M scheduled to be turned on by referring to the line configuration information of the in-house power source of the power plant in the storage unit 11 via the calculation unit 12, and Information about the starting power characteristics of the active power P and reactive power Q characteristics is given to the calculation unit 12.

The calculation unit 12 searches for a supply line that can supply the power of the power conditioning system PCS to the scheduled motor M, and connects the output side of the power conditioning system PCS to the corresponding circuit breaker CBP. Generally, if the power conditioning system PCS having a sufficient number and capacity for complex on-site power supply facilities can be pre-arranged, such a response is not necessary, but in many cases the circuit breaker is placed in an open state. There is a high possibility that a line between the power conditioning system PCS and the planned circuit breaker is not formed.
For this reason, it is thought that there are many scenes where it is necessary to first secure a route between the power conditioning system PCS and the scheduled circuit breaker.

  In addition, in the calculation unit 12, after confirming the power supply line, the circuit breaker CBP is turned on (signal SG1), then the circuit breaker CB is turned on (signal SG3), and the power supply from the power conditioning system PCS is started (signal SG2). Instruct sequentially. In this case, the operation of the power conditioning system PCS and the power supply can be realized at the timing prior to the actual introduction of the circuit breaker CB, so that the power supply line PB can be a master and the power supply line PA can be placed in a follow-up position. Is possible.

  FIG. 4 is a flowchart showing a series of processing contents in the control device 10 of the power conditioning system PCS. In the first processing step S1 of this flow, information on the closing command of the circuit breaker CB for connecting to the power source of the motor M is obtained. If there is no instruction to turn on the circuit breaker CB, it waits until it is. Note that this circuit breaker CB turn-on command is issued to a plurality of auxiliary machines, and it may be necessary to turn on a plurality of circuit breakers CB. It is good to confirm the presence or absence.

  In the next processing step S2, the information on the line configuration of the on-site power source of the power plant in the storage unit 11 is referred to identify the motor M scheduled to be turned on, and start of the active power P and reactive power Q characteristics of the motor M scheduled to be turned on. The time characteristic information is obtained in the calculation unit 12. In addition, information on a supply line that can supply the electric power of the power conditioning system PCS to the scheduled electric motor M is obtained in the calculation unit 12.

  In the processing step S3, a supply line that can supply the electric power of the power conditioning system PCS to the scheduled electric motor M is determined, and a circuit breaker CBP input command S1 for selecting the circuit breaker CBP and connecting it to the bus BUS is output. Output from the unit 14.

  In the processing step S4, the upper transformer should bear the calculation unit 12 by using the information on the starting characteristics of the active power P and reactive power Q characteristics of the scheduled charging motor M required by the scheduled switching circuit breaker CB. The power PA and the power PB to be borne from the power conditioning system PCS are determined. In addition, the process of process step S4 may be performed before process step S3. The sharing command of the active power P and the reactive power Q to be borne by the power conditioning system PCS thus determined is determined as a function of time such as PB of d and e of FIG. The active power P and the reactive power Q that should be borne by the power conditioning system PCS can be said to be power (support power) that supports the power PA that should be borne by the upper transformer.

  In the processing step S5, the operation of turning on the circuit breaker CB (signal SG3) and the start of power supply from the power conditioning system PCS (signal SG2) are sequentially instructed. In this case, the operation of the power conditioning system PCS and the power supply can be realized at the timing prior to the actual introduction of the circuit breaker CB, so that the power supply line PB can be a master and the power supply line PA can be placed in a follow-up position. Is possible.

  In addition, in realizing the closing operation of the circuit breaker CB in the processing step S5, the explanation is made on the premise of the following viewpoints, but these points may be separately considered or studied. For example, since the circuit breaker is turned on on an AC electric circuit, an electrical matching procedure of voltage, frequency, and phase matching is necessary, but this is a so-called synchronous turning operation. The discussion on the detection waveform of the voltage detection instrument, the operation speed of the circuit breaker itself, and the required time is omitted here. Similarly, practical methods related to electrical product protection and circuit protection on electrical systems are also important issues in circuit design planning, but are assumed on the assumption that they will be operated in additional circuit configurations. There is a need to reasonably understand and detect electrical failure events. Under the condition that this additional circuit configuration is used, a circuit that is affected by changes in the flow current is defined, and the input / output balance at each observation point is monitored to determine normality / abnormality. To do. This is because it is derived attributed from the setting event of temporary configuration operation and has the intention of eliminating the influence on the protection system of the existing circuit as much as possible. In the sense of simplifying the concept of sharing responsibility for protection, the implementation of the function is provided on the additional device side from the viewpoint of fulfilling the protection function. At the same time, if there is an influence on the calculation after detection of the sensor such as the voltage and current of the existing protection circuit, it shall be dealt with by bias setting for preventing unnecessary operation.

  In processing step S6, it is confirmed that a condition for stopping the operation of the power conditioning system PCS is satisfied, and in step S7, the operation of the power conditioning system PCS is stopped. In this case, it is preferable to open the circuit breaker CBP and exclude the power conditioning system PCS from the bus BUS. The condition for stopping the operation is preferably satisfied when, for example, the active power P and the reactive power Q shown in d and e of FIG. 2 reach the rated values.

  Although the above description has been made with the example of the simplified system configuration in FIG. 1, it is actually performed among a plurality of devices, a plurality of buses, a line, and a circuit breaker, and the function to be activated has various aspects. It is general that it is. Therefore, in the above operation, the total power is obtained in units of transformers, the sharing is determined in this unit to determine the amount of power to be supplied, and in cases where it is necessary to supply power to multiple transformers, the power supplied by the power conditioning system PCS Are sequentially supplied in time series as the total amount of the plurality of transformers.

  Although FIG. 1 is described in a very simplified manner for the purpose of explaining the concept of the in-house substation equipment 100, in practice, switches such as a transformer, a bus, a plurality of circuit breakers, and switches are housed together in a metakura. There are many. FIG. 8A shows an example of a conventional Metakura M / C, and switches such as a transformer, a bus bar, a plurality of circuit breakers and switches in a casing (metal clad) fixedly arranged on the floor F. Are stored together. Electric power is supplied from the upper power supply G on the right side and sent to the downstream load M on the left side through a cable in a pit arranged under the floor in the figure.

  FIG. 8B shows an example of a metaclave M / C according to the present invention. A portable power compensator (power conditioning system PCS and large-capacity capacitor 104) is appropriately connected to the metacla M / C. . The connection location can be arbitrarily set, and in the illustrated example, it is the most downstream position of the M / C. However, this may be a position immediately upstream of the M / C, a position near the motor downstream of the M / C, or the like. Further, since the cooperative operation with the M / C switching operation is performed, it is preferable to configure the signal transfer line 15 (dotted line) for the control confirmation operation in a wired or wireless manner.

  In carrying out the present invention, the purpose is to rationally compensate for the energy in the electric circuit, which is characterized by being temporary, so the simplicity of electrical protection in the temporary electrical system is reduced. It is better to maintain the protection method. For this purpose, equipment related to electrical system protection is provided in the incidental part of the capacitor equipment that determines the hardware to be added. Specifically, an electrical abnormality determination circuit is provided there. It should be noted that the device to which the circuit breaker subject to circuit interruption as a result of determination is not defined. By doing so, it is easy to distinguish between malfunctioning and malfunctioning of the equipment from the viewpoint of protection, which is also preferable in terms of troubleshooting.

  This protection concept is based on the use of a large-capacity capacitor for protection of the electrical system in the range including the circuit that is affected by changes in voltage and current due to the connection of the capacitor power supply (large-capacity capacitor and power-conditioning system PCS) to the existing circuit. It is proposed that the device side to be included should have a normal / abnormal judgment circuit for the electrical system.

  In the second embodiment, another application example of the power compensation device (the power conditioning system PCS and the large-capacity capacitor 104) will be described.

  Fig. 5 assumes the switching of the power supply system from the upper power supply on the premise of the two types of power buses provided inside the power plant. The flow of electricity from one power supply system is changed to the flow from the other. This considers the switching constraint condition that the voltage and phase difference between the two must be within the allowable range when switching.

That is, in the example of FIG. 5, the bus BUS1 is connected to the transformer Tr1 and the bus BUS2 is connected to the transformer Tr2. Make up line. The buses BUS1 are connected to electric motors M1 and M2 as loads, and the buses BUS2 are connected to electric motors M3 and M4 as loads. The power conditioning system PCS is connected between the bus BUS1 and the bus BUS2, so that power can be supplied to both. In this case, it is assumed that the bus voltage V1 of the bus BUS1 and the bus voltage V2 of the bus BUS2 have different phases.
Therefore, when switching the flow of electricity from one power supply system (BUS1) to the flow from the other power supply system (BUS2), it is necessary to consider that the voltage and phase difference between the two are suppressed to an allowable range.

  In the case of such a configuration, in the configuration capable of communicating between the power supply bus BUS1 indicated by the voltage V1 on the left side of FIG. 5 and the power supply bus BUS2 indicated by the voltage V2 on the right side of FIG. 5, the vector amounts of both voltage vectors V1 and V2 However, it is common to put in the circuit breaker CBT on the connection line in a reasonable match.

  FIG. 6 is a diagram for explaining the concept of deviation vector cancellation. Here, a means for reducing the local fluctuation caused by the transient mismatch at the time of the contact and realizing smooth and smooth switching is provided. This method introduces the idea of deviation vector cancellation shown in FIG. Here, the deviation vector is obtained by calculating the difference between the voltage vectors V1 and V2 of both target buses BUS1 and BUS2, and knowing the value, calculating the cancel vector with the sign inverted, A power vector having phase characteristics is set.

  The electric energy held by the large-capacitance capacitor 104 described above is applied to the power source of the electric power vector, and the magnitude of the instantaneous shock is reduced. Thereafter, the magnitude of the electric power vector is intentionally attenuated "over time t0", so that the power vector is decommissioned after being used. Here, the purpose is to mitigate the instantaneous shock, and it does not ask whether the direction of power flow thereafter is right or wrong.

  The above content can be used for shock mitigation when the system is parallel to the generator in the sense that the different systems are connected while being controlled.

  In the embodiment of the present invention described above, the above-mentioned problem is regarded as improving the instability of the “dynamic” and “transient” power supply system in plant operation, and solved by eliminating the instability. Is. Here, as a basic measure, a new capacitor facility with a capacity that can compensate for energy is newly introduced, and an algorithm that combines appropriate timing control and quantitative control is incorporated into the system. In order to suppress the disturbance phenomenon, we decided to control power (energy) compensation based on the concept of planned harmony of transient power waveforms. As a result, restrictions on the overall system design are relaxed.

  The basic concept of this dynamic (or transitional) harmony is to compensate for the excess and deficiency in the setting of equipment capacity. It is possible to grasp the phase of each voltage / current phase on the target power supply bus, the phase difference between the phases, and the phase (phasor) information of the advance / delay vector calculation waveform. It is possible to respond to one purpose with a plurality of (multi-) element groups so that not only the capacity of the product but also the overall purpose can be achieved only after being combined.

  As for the capacitor to be introduced, as a source of energy (energy source to be charged) as the compensation energy storage element, in addition to charging from the on-site power source, this is a technology that has already been presented to the world as an idea. The charging method for atmospheric space electric field application can be used together. That is, a capacitor (eg, lithium ion capacitor) configured in parallel using an electrode plate that is not electrostatically shielded in the atmosphere is charged according to the transient circuit characteristics obtained by controlling the grounding condition and the voltage control condition of the system. It is better to use the phenomenon to “power generation + charging”.

  In Example 3, there is no structural difference from Example 1, but in FIG. 2, not only in the transient region but also in a part of the steady load region, alternating current derived from natural energy such as a large-capacitance capacitor. By making greater use of electric power, the efficiency of the entire power generation system can be “significantly” improved.

  Specifically, the charging charge to the large-capacity capacitor described above is based on the charging process derived from atmospheric electric field fluctuations, so that the main body of the rotating body is not used, and light (electric) conversion technology such as solar cells is not used. This is a proposal for a new “combined process” that does not require significant expansion of the ground contact area by simply using a combination with a static process-based method of electric / electric conversion. Based on the concept of capacity allowance, regular system assistance is also possible. In addition, it is detailed in patent document 1 about implement | achieving the charge charge to a high capacity | capacitance capacitor by the charge process derived from an atmospheric electric field fluctuation | variation.

  In order to make a quantitative contribution that can make a significant contribution to this efficiency evaluation, for example, a plurality of combinations of capacitors and batteries are provided, and the concept of “always available” is applied on an average over time, and natural environmental conditions Although matching is required, the essential explanation has already been improved in efficiency with the above configuration.

  As described above, the present invention has been described with reference to the embodiments, but according to the present invention, in the system / specification of the power source configuration of the thermal power generation system, etc. Stable dynamic transition will be realized by further rationalization of facility capacity (specifications), cost reduction by relaxing constraints on facility specifications related to dynamic or transient operation, and improvement of fluctuation situation due to transient phenomenon In addition, since the real energy source for obtaining these effects can be allocated from natural energy, it is an effective solution in terms of responding to the social problem of low carbonization.

  Furthermore, in this new configuration, because it is a proposal for a new “combined process” that does not require significant expansion of the installation area, it will be referred to as “green combined” here. If the policy is to increase, the ratio of the power plant is reduced and the effective efficiency is increased, which is preferable.

BUS: AC power supply bus, PCS: Power conditioning system, 104: Large capacity capacitor (for example, lithium ion capacitor), Tr: Transformer, CB: Circuit breaker, 10: Control device for power conditioning system, 11: Storage unit, 12 : Arithmetic unit, 13: input unit, 14: output unit

Claims (9)

A transformer connected to an AC power supply, a bus provided on the secondary side of the transformer, a power supply system including a load connected to the bus via a circuit breaker,
A large-capacity capacitor that holds DC power, and a power conditioning system that adjusts the power of the capacitor and supplies the power to the load.
The power conditioning system adjusts the power from the large-capacitance capacitor and supplies the power to the load so that the assist power is determined using the start-up characteristics of the load when the circuit breaker is turned on. Power system. The power supply system according to claim 1,
The power conditioning system obtains an instruction to turn on the circuit breaker, determines support power from a start characteristic of the load to be turned on, adjusts power from the large-capacitance capacitor, and supplies the load to the load. Power system. The power supply system according to claim 1 or 2,
The power supply system, wherein power supply from the large-capacity capacitor to the load is performed prior to power supply from the AC power supply to the load. The power supply system according to any one of claims 1 to 3,
The power supply system is characterized in that power supply from the large-capacity capacitor to the load is continued until the power of the load reaches rated power. The power supply system according to any one of claims 1 to 4, wherein:
The power storage system is characterized in that the large-capacity capacitor is a lithium ion capacitor, and the power conditioning system converts DC power held by the lithium ion capacitor into power at startup of the load. First and second transformers connected to an AC power source, first and second buses connected to secondary sides of the first and second transformers, respectively, between the first and second buses A power supply system including a tie line between buses connected via a circuit breaker for connection, a load connected to the first and second buses via a circuit breaker,
A large-capacity capacitor that holds DC power, and a power conditioning system that adjusts the power of the capacitor and supplies the power to the load.
The power conditioning system is connected to the tie line between the buses, and supplies electric power in which the voltage between the first and second buses and the frequency / phase of each phase are adjusted when the connection breaker is turned on. Power supply system characterized by The power supply system according to claim 6,
The deviation vector is calculated from the voltage measurement value between the first and second buses, a deviation cancellation vector for canceling the deviation vector is obtained, and the power obtained from the deviation cancellation vector is placed on the connection line of both buses. A power supply system that suppresses an impact by suppressing a phase difference voltage generated at the time of connection by applying, and then attenuating a power level from an additional capacitor power supply. The power supply system according to any one of claims 1 to 7,
For protection of electrical systems that include electrical circuits that are affected by changes in voltage and current due to the connection of the power supply including large capacitors to the existing circuit, the normality / abnormality of the electrical system on the power supply including the large capacitors A power supply protection system comprising: The power supply system according to any one of claims 1 to 8,
A power supply system comprising a power generation system including a rotator generator on the AC power supply side, and using an energy system derived from atmospheric electric field fluctuations for charging the large-capacity capacitor.

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