Method for displaying remaining capacity in an AC generator and display device for displaying remaining capacity

Abstract

The remaining capacity of the AC generator is accurately calculated and displayed as active power [kW] for each three-phase and single-phase output system. [Solution] The AC generator 1 is equipped with voltage detection means and current detection means that detect the instantaneous values ​​V and I of voltage and current for each of the three-phase and single-phase AC output systems 3φ and 1φ and transmit them to the controller 70. Based on the received instantaneous values ​​V and I of voltage and current, the controller 70 calculates the active power P [kW] and apparent power S [kVA] used, and calculates the ratio of active power P to apparent power S (P / S) as the power factor PF. Then, the rated output of the generator body 2, the rated output Pr ([kVA]), is corrected using this power factor PF to obtain the rated active power Pr active [kW] is calculated, and this rated active power Pr active By subtracting the active power used P[kW] from [kW], the exact remaining capacity can be calculated for each of the three-phase and single-phase AC output systems (3φ and 1φ).

Description

[Technical Field]

[0001] The present invention relates to a method for displaying the remaining capacity of an AC generator and a remaining capacity display device, and more particularly to a method for displaying the current remaining capacity of an AC generator, for use as a reference when connecting an additional load to an AC generator that already has a load connected, in order to determine whether or not an additional load can be connected. [Background technology]

[0002] In construction sites, event venues, and other outdoor locations, when various power-operated work machines, lighting fixtures, video and audio equipment, and other devices (hereinafter simply referred to as "loads") are used, an engine-driven AC generator is used as the power source for such loads. This generator consists of a synchronous generator body and an engine that drives the generator body, both housed in a soundproof enclosure and packaged together.

[0003] As shown in Figure 7, some generator units mounted on such AC generators are configured to selectively output three-phase AC (for example, three-phase 200V AC) when connected in three-phase mode, and single-phase AC (for example, single-phase 200V and single-phase 100V AC) when connected in single-phase mode, by switching the connection of the armature coils V, W, and U from three-phase connection (see Figure 7(A)) to single-phase connection (see Figure 7(B)).

[0004] Furthermore, as shown in Figure 8, in addition to the three-phase windings V, W, and U connected in a Y configuration as armature coils, a predetermined auxiliary winding V' has been added to the generator body 102. This configuration allows for simultaneous output of single-phase AC (for example, single-phase 200V and single-phase 100V) and three-phase AC (for example, three-phase 200V) from a single generator body 102 without changing the connection state of the armature coils, unlike the generator body described with reference to Figure 7.

[0005] In the AC generator 100 equipped with the generator body 102 configured as described above, as shown in Figure 9, an AC output system 110 is formed by an output circuit 120 connected to the output sections u, v, w, v' of the generator body 102 and output terminal blocks (151, 152) connected to the output circuit 120. By connecting loads (L1 to L4) to the output terminal blocks (151, 152), the power generated by the generator body 102 can be supplied to the loads (L1 to L4) via the AC output system 110.

[0006] In the illustrated example, the output circuit 120 described above is configured with a three-phase output circuit 130 (130U, 130V, 130W) and a single-phase output circuit 140 (140U, 140V', 140W). A three-phase output terminal block 151 is connected to the three-phase output circuit 130 (130U, 130V, 130W), and a single-phase output terminal block 152 is connected to the single-phase output circuit 140 (140U, 140V', 140W), thereby forming a three-phase AC output system (for example, a three-phase AC 200V output system) and a single-phase AC output system (for example, a single-phase AC 200V and single-phase AC 100V output system).

[0007] In this way, the connection of loads (L1 to L4) to the output terminal blocks 151 and 152 provided on the AC output system 110 can be done by adding loads even if loads are already connected, as long as it is within the range of the rated output of the generator body 102 (hereinafter referred to as "generator rated output"). Such additional load connections can be made, for example, by adding loads to the same output system (for example, by connecting a new 200V three-phase AC load to a 200V three-phase AC output system that already has loads connected), or, in the case of an AC generator 100 equipped with a generator body 110 capable of simultaneous output of three-phase AC and single-phase AC, by adding loads to different types of AC output systems (for example, by adding new loads to the 200V single-phase AC and / or 100V single-phase AC output system when a load is already connected to the 200V three-phase AC output system).

[0008] However, if a load is connected exceeding the rated output of the generator, there is a risk that the armature coil of the generator main body 102 may burn out due to the generation of overcurrent, or the operation may be interrupted due to the emergency stop of the alternator 100 to avoid such burn out.

[0009] Therefore, the user needs to connect an additional load within the remaining capacity obtained by subtracting the power consumption of the connected load from the rated output of the generator.

[0010] However, it is difficult to immediately grasp the remaining capacity from the displays of the voltmeter and ammeter provided in the alternator 100, and as a result, it becomes difficult to determine whether it is possible to connect the load to be additionally connected.

[0011] Therefore, there has been a demand to enable the display of the remaining capacity on, for example, the operation panel of the alternator 100. In response to such a demand, an alternator capable of supplying power with a plurality of power supply specifications (for example, three-phase AC and single-phase AC) has been proposed, which can display the remaining capacity for each power supply specification (see Patent Documents 1 and 2 cited below).

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0013] In the above Patent Documents 1 and 2 cited as prior art documents, since the remaining capacity is displayed for each power supply specification, the remaining capacity display can be referred to when determining whether it is possible to connect an additional load for each power supply specification.

[0014] However, in the AC generator described in Patent Document 1 of the above prior art documents, the remaining capacity for each power supply specification is displayed using apparent power value [kVA], which is a different unit from the active power value [kW] that is commonly used to display power consumption on the load side.

[0015] Therefore, in order to accurately determine whether an additional load can be connected, it is necessary to either convert the remaining capacity displayed as apparent power [kVA] to active power [kW] and compare them, or convert the power consumption [kW] of the load displayed as active power [kVA] to apparent power [kVA] and compare them, making it impossible to immediately determine whether an additional load can be connected.

[0016] Furthermore, if a user mistakenly believes that the apparent power value [kVA] used to indicate the remaining capacity of an AC generator and the active power value [kW] used to indicate the power consumption on the load side are common units and connects additional loads, there is a possibility that the connected loads will exceed the generator's rated output. In this case, an overcurrent may occur in the generator itself, causing the emergency stop device to activate to prevent burnout of the armature windings, resulting in an emergency shutdown of the AC generator and potentially cutting off power supply to the connected loads.

[0017] Therefore, it is preferable to indicate the remaining capacity of an AC generator using the active power value [kW], which is commonly used to indicate power consumption on the load side, rather than the apparent power value [kVA].

[0018] Among the prior art documents cited, Patent Document 2 addresses the request to display the remaining capacity of an AC generator using the active power value [kW], which is used to display the power consumption on the load side (paragraph

[0006] of Patent Document 2), and displays the remaining capacity of an AC generator using the active power value [kW] instead of the apparent power value [kVA].

[0019] However, the accuracy of the remaining capacity value [kW] displayed in Patent Document 2 is not guaranteed.

[0020] In other words, Patent Document 2 compares the "remaining active power [kW]" and the "remaining apparent power [kVA]" and displays the smaller value as the "remaining active power [kW]" (Claim 1 of Patent Document 2). However, as will be detailed below, neither the "remaining active power [kW]" nor the "remaining apparent power [kVA]" accurately displays the "remaining capacity of the AC generator [kW]," and therefore it is not possible to display the accurate "remaining active power [kW]."

[0021] Further details are provided below.

[0022] (1) Inaccuracy when the remaining power [kW] of the active power value is used as the remaining capacity [kW]. (1-1) Use of an inaccurate power factor (cosθ) In Patent Document 2, the "remaining power of the active power value [kW]" is calculated by subtracting the "power consumption [kW]" corresponding to the power consumed by the already connected load from the rated output [kW] of the engine.

[0023] In Patent Document 2, this "power consumption [kW]" is determined as the product of the effective value of the voltage between the output terminals and the effective value of the current flowing through the output terminals, multiplied by the power factor cosθ (paragraph

[0036] of Patent Document 2).

[0024] Furthermore, the "power factor cosθ" used to calculate the "power consumption [kW]" is determined by finding the phase difference θ from the periodic change of the voltage detection value and the periodic change of the current detection value, and then finding the power factor cosθ from this phase difference θ (paragraph

[0037] of Patent Document 2).

[0025] Here, the periodic changes in the detected voltage and current are represented by voltage and current waveforms, but the voltage and current waveforms measured by an AC generator are not necessarily clean sine waves and may be distorted.

[0026] On the other hand, the power factor cosθ calculated based on the phase difference θ between the voltage waveform and the current waveform assumes that the voltage and current waveforms are clean sine waves. Therefore, the power factor cosθ obtained from the phase difference θ of distorted voltage and current waveforms is not accurate.

[0027] In particular, under conditions of voltage imbalance or during transient response, voltage and current waveforms are prone to distortion, and large errors can occur in the calculated value of the power factor cosθ.

[0028] As a result, if the "power consumption [kW]" is calculated using a power factor cosθ with such a large error, the "power consumption [kW]" will also be inaccurate, and the "remaining active power [kW]" calculated using this "power consumption [kW]" may also be inaccurate.

[0029] (1-2) Inaccuracy of the remaining power [kW] calculated based on the engine's rated output. In Patent Document 2, the active power consumed by the connected load is determined as "power used" [kW] by the method described above, and then this "power used" [kW] is used in the following equation Remaining active power [kW] = Engine rated output [kW] - Power consumption [kW] The remaining power [kW] of the AC generator is calculated using this method.

[0030] In engine-driven generators, an engine with a rated output [kW] that is significantly larger than the generator's rated output [kW] is often used to ensure that the generator itself operates smoothly.

[0031] Therefore, in the case of an AC generator equipped with an engine with a higher output than the generator itself, if an additional load is connected within the range of the "remaining power [kW]" calculated using the method described above, the total power consumption [kW] of the loads may exceed the generator's rated output [kW], even if the total power consumption [kW] of the loads does not exceed the engine's rated output [kW].

[0032] In this manner, if a load exceeding the generator's rated output [kW] is connected, the generator itself will be overloaded, resulting in an overcurrent. This could cause the generator to burn out. Furthermore, if a safety device activates to protect the generator from such burnout and the AC generator is shut down, the power supply to the connected load will also be cut off.

[0033] (2) Inaccuracy of using the remaining capacity of the apparent power value [kVA] as the remaining capacity of the active power value [kW] In Patent Document 2, the smaller of the aforementioned "remaining active power [kW]" and "remaining apparent power capacity (kVA)" is used as the display value for "remaining active power capacity [kW]".

[0034] In other words, the "remaining active power [kW]" and the "remaining apparent power capacity [kVA]" are compared, and if the value of the "remaining apparent power capacity [kVA]" is smaller, the value of the "remaining apparent power capacity [kVA]" is displayed as the remaining capacity [kW] of the AC generator, with only the unit changed to represent the active power value [kW].

[0035] However, the remaining capacity of the active power value [kW] displayed in this way, although the units have been changed, is essentially the remaining capacity of the apparent power value [kVA] and therefore lacks accuracy.

[0036] As a result, when the value of "remaining apparent power capacity [kVA]" is displayed as the remaining active power capacity [kW], even if a load with a power consumption [kW] within the range of the displayed remaining capacity [kW] is added, the total power consumption of the load may exceed the generator's rated output [kW].

[0037] As explained above, although AC generators that can display remaining capacity have been proposed, conventional AC generators, such as those in Patent Document 1, display the remaining capacity using apparent power value [kVA], which is difficult to understand, or those, such as those in Patent Document 2, which display the remaining capacity using active power value [kW], but the value is inaccurate and unreliable, making them difficult for users to use.

[0038] Therefore, the present invention has been made to overcome the drawbacks of the above-mentioned prior art, and aims to provide a method for displaying the remaining capacity of an AC generator and a remaining capacity display device that can accurately calculate and display the remaining capacity in terms of the active power value [kW] of the AC generator for each output system provided in the AC generator (for example, each three-phase AC output system and each single-phase AC output system). [Means for solving the problem]

[0039] The means for solving the problem are described below, along with the reference numerals used in the embodiments for carrying out the invention. These reference numerals are intended to clarify the correspondence between the claims and the descriptions of the embodiments for carrying out the invention, and needless to say, they are not used restrictively to interpret the technical scope of the present invention.

[0040] To achieve the above objective, the method for displaying remaining capacity in the AC generator 1 of the present invention is as follows: In an AC generator 1 comprising a generator body 2, a three-phase output terminal block 51, a single-phase output terminal block 52, a three-phase output circuit 30U, 30V, 30W connecting the generator body 2 and the three-phase output terminal block 51, and a single-phase output circuit [40U, 40V', 40W (see Figure 1); or 40U2, 40N, 40W2 (see Figure 2)] connecting the generator body 2 and the single-phase output terminal block 52, a three-phase AC output system 3φ is formed by the three-phase output circuit and the three-phase output terminal block 51 to output three-phase AC to a three-phase load L1, and a single-phase AC output system 1φ is formed by the single-phase output circuit and the single-phase output terminal block 52 to output single-phase AC to single-phase loads L2-L4, the method for displaying the remaining capacity of the AC generator 1 is as follows: A voltage detection process that sequentially detects the instantaneous voltage V of the three-phase AC output system 3φ and the single-phase AC output system 1φ, A current detection process that sequentially detects the instantaneous value I of the current in the three-phase AC output system 3φ and the single-phase AC output system 1φ, Based on the instantaneous voltage V and the instantaneous current I, a calculation process for calculating the active power P used is performed, which is the power used at the time of detection of the instantaneous voltage V and the instantaneous current I, and the three-phase AC output system 3φ and the single-phase AC output system 1φ in terms of active power [kW]. The effective value V of the voltage calculated based on the instantaneous value V of the aforementioned voltage. rms And the effective value I of the current calculated based on the instantaneous value I of the current. rms Based on the above, an apparent power usage calculation process is performed to calculate the apparent power usage S, which is the power used in terms of apparent power values ​​[kVA] of the three-phase AC output system 3φ and the single-phase AC output system 1φ at the time of detection, A power factor calculation process that calculates the power factor PF of the generator body 2 at the time of detection based on the ratio (P / S) of the active power P used and the apparent power S used, By correcting the generator rated output Pr, which is the rated output of the generator body 2, using the power factor PF, the rated output of the generator body 2 at the time of detection is obtained as the rated active power Pr. active The rated active power calculation process is performed as follows: The difference between the rated active power and the active power used is the remaining capacity P of the AC generator 1 at the time of detection. remain Calculate as [kW], remaining capacity calculation process, including, In the remaining capacity calculation process, the remaining capacity P remain [kW] represents the remaining capacity P of the three-phase AC output system 3φ. 3φ remain And the remaining capacity P of the single-phase AC output system 1φ 1φ remain The method is characterized by calculating each of the following (Claim 1).

[0041] The aforementioned single-phase AC output system 1φ is a low-voltage single-phase AC output system [1φ] that outputs a single-phase voltage (for example, 100V) that is predetermined to be lower than the three-phase output voltage (for example, 200V or 400V). U-V’, 1φ W-V’ (see Figure 1); or, 1φ U2-N , 1φ W2-N (see Figure 2)], when including in the remaining capacity calculation process, the calculation of the remaining capacity P of the single-phase AC output system 1φ 1φ remain is preferably included as the calculation of the remaining capacity of the low-voltage single-phase AC output system (1φ U-V’ , 1φ W-V’ or, 1φ U2-N , 1φ W2-N )(Claim 2).

[0042] [[ID=2)] Further, when the single-phase AC output system 1φ includes a high-voltage single-phase AC output system 1φ that outputs a single-phase output with the same voltage as the three-phase output voltage performed by the generator main body 2 U-W , when including in the remaining capacity calculation process, the calculation of the remaining capacity P of the single-phase AC output system 1φ 1φ remain is preferably further included as the calculation of the remaining capacity P of the high-voltage single-phase AC output system 1φ U-W (Claim 3). 1φU-W remain

[0043] <; The calculation of the aforementioned useful power P [kW] can be calculated by integrating the product of the instantaneous value V of the voltage and the instantaneous value I of the current and averaging over one cycle (Claim 4).

[0044] The remaining capacity P remain [kW] calculated in this way is preferably included in the remaining capacity display process of displaying it on a display means 80 such as a monitor (Claim 5).

[0045] Furthermore, the remaining capacity display method in the AC generator 1 of the present invention may further include a determination process for determining whether a load planned for new connection can be connected, and a determination result display process for displaying the determination result obtained in the determination process on a display means Ǹ (Claim 6).

[0046] In this case, in the determination process, further, the current value I of the generator main body 2 at the time of detection from the useful power P [kW] of the three-phase AC output system 3φ and the single-phase AC output system 1φworking [A] is calculated using current value, From the rated current value Ir[A] of the generator body 2, the operating current value I working Subtracting [A], the remaining current value I of the generator body 2 remain The process for calculating the remaining current value to calculate [A], Based on the active power consumption [kW], which is the power consumption at the active power value of the load to be newly connected, and the power factor, the load current value I is the current value that flows through the load when the load is connected. load The load current value calculation process for calculating [A], The aforementioned residual current value I remain [A] and the load current value I load [A] is compared with the load current value I load [A] is the remaining current value I remain The system may include a comparison and determination process that determines whether the connection of the load to be newly connected is possible when it is smaller than [A] (Claim 7).

[0047] Furthermore, the remaining capacity display device 60 in the AC generator 1 of the present invention is In an AC generator 1, the remaining capacity display device 60 comprises a generator body 2, a three-phase output terminal block 51, a single-phase output terminal block 52, a three-phase output circuit 30U, 30V, 30W connecting the generator body 2 and the three-phase output terminal block 51, and a single-phase output circuit [40U, 40V', 40W (see Figure 1); or 40U2, 40N, 40W2 (see Figure 2)] connecting the generator body 2 and the single-phase output terminal block 52, wherein a three-phase AC output system 3φ is formed by the three-phase output circuit and the three-phase output terminal block 51 to output three-phase AC to a three-phase load L1, and a single-phase AC output system 1φ is formed by the single-phase output circuit and the single-phase output terminal block 52 to output single-phase AC to single-phase loads L2-L4, Voltage detection means 61U, 61V, 61W, 61V', 61N, 61U2, 61W2 sequentially detect the instantaneous voltage V of the three-phase AC output system 3φ and the single-phase AC output system 1φ, Current detection means 62U, 62V, 62W, 62U2, 62V', 62W2 sequentially detect the instantaneous value I of the current in the three-phase AC output system 3φ and the single-phase AC output system 1φ, Based on the instantaneous voltage V and the instantaneous current I, a means for calculating the active power P used is calculated by determining the active power value [kW] of the three-phase AC output system 3φ and the single-phase AC output system 1φ at the time of detection of the instantaneous voltage V and the instantaneous current I. The effective value V of the voltage calculated based on the instantaneous value V of the aforementioned voltage. rms And the effective value I of the current calculated based on the instantaneous value I of the current. rms Based on the above, an apparent power usage calculation means 72 calculates the apparent power usage S, which is the power used in terms of apparent power value [kVA] of the three-phase AC output system 3φ and the single-phase AC output system 1φ at the time of detection, A power factor calculation means 73 calculates the power factor PF of the generator body 2 at the time of detection based on the ratio (P / S) of the active power used P and the apparent power used S, The generator rated output Pr, which is the rated output of the generator body 2 stored in the storage means 75, is corrected using the power factor PF, thereby converting the rated output of the generator body 2 at the time of detection to the rated active power Pr. active The rated active power calculation means 74 calculates as follows: The difference between the rated active power and the active power used is the remaining capacity P of the AC generator 1 at the time of detection. remain The remaining capacity is calculated as [kW], by the remaining capacity calculation means 76. Equipped with, The remaining capacity calculation means 76 determines the remaining capacity P remain [kW] represents the remaining capacity P of the three-phase AC output system 3φ. 3φ remain And the remaining capacity P of the single-phase AC output system 1φ 1φ remain The method is characterized by calculating each of the following (Claim 8).

[0048] The aforementioned single-phase AC output system 1φ is a low-voltage single-phase AC output system [1φ] that outputs a single-phase voltage (for example, 100V) that is predetermined to be lower than the three-phase output voltage (for example, 200V or 400V). U-V’ ,1φ W-V’ (See Figure 1), or 1φ U2-N ,1φ W2-N (See Figure 2) If it includes, The remaining capacity P of the single-phase AC output system 1φ is calculated by the remaining capacity calculation means 76. 1φ remain In calculating the above, the low voltage single-phase AC output system (1φ U-V’ ,1φ W-V’ , or 1φ U2-N ,1φ W2-N ) remaining capacity (1φ U-V’ remain ,1φ W-V’ remain , or 1φ U2-N remain ,1φ W2-N remain It is preferable to include the calculation of (Claim 9).

[0049] Furthermore, the single-phase AC output system 1φ provides a single-phase output with the same voltage as the three-phase output voltage, which is a high-voltage single-phase AC output system 1φ. U-W If it includes, The remaining capacity P of the single-phase AC output system 1φ is calculated by the remaining capacity calculation means 76. 1φ remain For the calculation, the high-voltage single-phase AC output system 1φ U-W Remaining capacity P 1φU-W remain It is preferable to include the calculation of (Claim 10).

[0050] The means for calculating the active power used 71 can be configured to calculate the active power used P [kW] by integrating the product of the instantaneous value V of the voltage and the instantaneous value I of the current and averaging it over one period (Claim 11).

[0051] The remaining capacity display device 60 displays the calculated remaining capacity P remain The system may further include a display means 80 such as a monitor that displays [kW] (Claim 12).

[0052] Furthermore, the remaining capacity display device 60 may also include a determination means 78 for determining whether or not it is possible to connect a load that is to be newly connected, and a display means 81 for displaying the determination result made by the determination means 78 (Claim 13).

[0053] In this case, the determination means 78, The current value I of the generator body 2 at the time of detection is obtained from the active power P [kW] used by the three-phase AC output system 3φ and the single-phase AC output system 1φ. working[A] is calculated by the current usage value calculation unit 78a, The rated current value Ir[A] of the generator body 2 stored in the storage means 75 is used to obtain the operating current value I working Subtracting [A], the remaining current value I of the generator body 2 remain [A] is calculated by the remaining current value calculation unit 78b, Based on the active power consumption [kW], which is the power consumption of the load to be newly connected, and the power factor, stored in the storage means 75, the load current value I, which is the current value that flows through the load when the load is connected, is calculated. load The load current value calculation unit 78c that calculates [A], The aforementioned residual current value I remain [A] and the load current value I load [A] is compared with the load current value I load [A] is the remaining current value I remain The system may further include a comparison and determination unit 78d that determines that it is possible to connect the load to be newly connected when the value is smaller than [A] (Claim 14). [Effects of the Invention]

[0054] With the configuration of the present invention described above, the remaining capacity display method for the AC generator 1 of the present invention and the remaining capacity display device 60 that implements this method can accurately calculate the remaining capacities of the three-phase AC output system 3φ and the single-phase AC output system 1φ, as described below.

[0055] In the present invention's method for displaying remaining capacity, the active power used P [kW] is calculated based on the instantaneous voltage V and instantaneous current I of the three-phase AC output system 3φ and the single-phase AC output system 1φ (for example, by integrating the product of the instantaneous voltage and current V and I and averaging it over one period), and the effective values ​​V of the voltage and current are used. rms ,I rmsBased on the ratio (P / S) of the apparent power used S [kVA] calculated based on the above, the power factor PF at the time of detection of the instantaneous voltage V and the instantaneous current I was calculated. Unlike the method of determining the power factor (cosθ) based on the phase difference θ between the voltage waveform and the current waveform, assuming that the voltage waveform and the current waveform are sinusoidal (see Patent Document 2 above), it was possible to calculate the accurate power factor PF without being affected by waveform distortion.

[0056] By accurately calculating the power factor PF in this way, the generator's rated output Pr ([kVA]) can be corrected using this power factor PF to obtain the accurate rated active power Pr of the three-phase AC output system 3φ and the single-phase AC output system 1φ at the time of detection. 3φ active ,Pr 1φ active [kW] can be calculated, and this accurate rated active power Pr 3φ active ,Pr 1φ active From [kW], the active power P used by the three-phase AC output system 3φ and the single-phase AC output system 1φ at the time of detection. 3φ ,P 1φ By subtracting [kW], the remaining capacity P of the three-phase AC output system (3φ) and the single-phase AC output system (1φ) can be calculated. 3φ remain ,P 1φ remain This could be determined as an active power value [kW] and as an accurate value.

[0057] As a result, the remaining capacity P was calculated. 3φ remain ,P 1φ remain [kW] is displayed numerically or on a meter on a display device 80 such as a monitor, or this remaining capacity P 3φ remain ,P 1φ remain By displaying the determination result on a display means 81 such as a monitor, which determines whether or not a newly planned load can be connected based on [kW], the user can easily and accurately determine whether or not a newly planned load can be connected, and the total power consumption of the load [kW] is equal to the rated active power Pr of the generator body 2. active By easily adjusting the current so that it does not exceed a certain limit, it was possible to suppress problems such as the generator body 2 becoming overcurrent and causing the AC generator 1 to make an emergency stop.

[0058] A single-phase AC output system 1φ is a low-voltage single-phase AC output system 1φ that outputs a single-phase output with a predetermined low voltage with respect to the three-phase output voltage performed by the generator main body 2. U-V’ , 1φ W-V’ , or 1φ U2-N , 1φ W2-N When including, in the remaining capacity calculation process performed by the remaining capacity calculation means 76, the remaining capacity P of the single-phase AC output system 1φ 1φ remain As, the low-voltage single-phase AC output system 1φ U-V’ , 1φ W-V’ By calculating the remaining capacity of, the capacity of the load that can be connected to the low-voltage single-phase AC output system 1φ U-V’ , 1φ W-V’ Can be accurately grasped.

[0059] Furthermore, when a high-voltage single-phase AC output system 1φ that outputs the same voltage as the three-phase output voltage performed by the generator main body 2 is provided in the single-phase AC output system 1φ U-W In the remaining capacity calculation process performed by the remaining capacity calculation means 76, the remaining capacity P of the single-phase AC output system 1φ 1φ remain As, furthermore the remaining capacity P of the high-voltage single-phase AC output system 1φ U-W By including, the user can accurately grasp the remaining capacity of each output system provided in the single-phase AC output system 1φ. 1φ U-W remain

[0060] When the remaining capacity P remain [kW] is displayed by displaying the determination result as to whether or not a load scheduled for new connection can be connected, or when including such a determination result in the display of the remaining capacity P remain [kW], the used current value I is subtracted from the rated current value Ir [A] of the generator main body 2 working [A] to calculate the remaining current value I remain [A], and from the active power consumption and power factor of the load scheduled for new connection stored in the storage means 75, the load current value I which is the current value flowing through the load when the load scheduled for new connection is connected load [A] is calculated, and the remaining current value I remain [A] and the load current value I load [A] are compared, and the load current value I load [A] is the remaining current value I remainBy determining that the connection of the new load is possible when the value is smaller than [A], it became possible to accurately determine whether or not the new load can be connected, even when the power factor of the already connected load and the power factor of the new load are different when connecting a new three-phase load. [Brief explanation of the drawing]

[0061] [Figure 1] An explanatory diagram of an AC generator equipped with a remaining capacity display device according to the present invention. [Figure 2] An explanatory diagram of another AC generator equipped with the remaining capacity display device of the present invention. [Figure 3] Functional block diagram of the remaining capacity display device of the present invention. [Figure 4] Correlation diagram between the rated active power Practive [kV] and power factor PF of the generator body (rated output 45kVA) used in the embodiment. [Figure 5] A graph showing the correspondence between the rated output [kW] of the engine, the rated current value Ir [A] of the generator body, the rated active power Practive [kW] of the generator body, and the active power used P [kW] in the embodiment. [Figure 6] An explanatory diagram showing an example of how the judgment result is displayed in the display means. [Figure 7] This is a diagram illustrating a conventional generator capable of selectively outputting three-phase AC and single-phase AC, with (A) showing a three-phase connection and (B) showing a single-phase connection. [Figure 8] A diagram illustrating a conventional generator capable of simultaneous output of single-phase and three-phase AC. [Figure 9] Diagram illustrating an AC generator. [Modes for carrying out the invention]

[0062] The configuration of the remaining capacity display device 60 in the AC generator 1 of the present invention will be described below with reference to the attached drawings.

[0063] [Overall configuration of the AC generator] Figure 1 shows an example configuration of an AC generator 1 equipped with the remaining capacity display device 60 of the present invention.

[0064] This AC generator 1 comprises a generator body 2 which is a synchronous generator, output circuits (20U, 20V, 20W, 20V'; 30U, 30V, 30W; 40U, 40V', 40W) connected to the output sections u, v, w, v' of the generator body 2, and output terminal blocks 51 and 52 connected to the output circuits, and is configured to supply power generated by the generator body 2 to loads L1 to L4 connected to the output terminal blocks 51 and 52.

[0065] The AC generator 1 shown in Figure 1 employs a generator body 2, which is capable of simultaneously outputting three-phase AC and single-phase AC, as explained with reference to Figure 8. This generator body 2 is equipped with three-phase windings V, W, U connected in a Y configuration with a 120° phase difference around the neutral point N, and an auxiliary winding V' connected to the three-phase windings V, W, U.

[0066] This auxiliary winding V' is connected to the neutral point N to generate an induced voltage that is half the vector sum of the induced voltage of the V-phase winding and has a phase difference of 180°. As a result, a predetermined voltage (200V at 50Hz and 220V at 60Hz in this embodiment) of three-phase AC is obtained from the output terminals v, w, and u provided at the respective ends of the three-phase windings V, W, and U, and in the illustrated example, the output terminal u provided at the end of the U winding and the output terminal v' provided at the end of the auxiliary winding V' are connected. The system is configured such that a single-phase AC voltage of a predetermined lower voltage (100V at 50Hz and 110V at 60Hz in this embodiment) is obtained between the output terminal w provided at the end of the W winding and the output terminal v' provided at the end of the auxiliary winding V', and a single-phase AC voltage of the same voltage as the three-phase AC voltage (200V at 50Hz and 220V at 60Hz in this embodiment) is obtained between the output terminal u provided at the end of the U winding and the output terminal w provided at the end of the W winding.

[0067] The frequency of the AC output by the generator body 2 (50Hz or 60Hz) can be switched by changing the rotational speed of the generator body 2 in accordance with the change in the rotational speed of the engine (not shown). However, the following explanation assumes that the AC generator 1 is used to obtain a 60Hz output.

[0068] Therefore, in the illustrated example, the combination of output terminals v, w, and u of the generator body 2 constitutes the three-phase output section (three-phase 220V output section) of the generator body 2, the combination of output terminals u and w constitutes a single-phase output section (single-phase 220V output section) that outputs the same voltage as the three-phase output section, and the combination of output terminals u, v' and w, v' constitutes a single-phase output section (single-phase 110V output section) that outputs a single-phase voltage predetermined to be lower than the three-phase output voltage.

[0069] In this embodiment, the output circuit described above is composed of a main output circuit 20U, 20V, 20W, 20V' connected to the output terminals u, v, w, v' of the generator body 2, a three-phase output circuit 30U, 30V, 30W connected to 20U, 20V, 20W of the main output circuit, and a single-phase output circuit 40U, 40V', 40W connected to 20U, 20W, 20V' of the main connection circuit.

[0070] Then, the three-phase output terminal block 51 is connected to the three-phase output circuits 30U, 30V, and 30W, and the single-phase output terminal block 52 is connected to the single-phase output circuits 40U, 40V', and 40W.

[0071] Therefore, a three-phase AC output system 3φ is formed by the 20U, 20V, 20W of the main output circuit, the three-phase output circuit 30U, 30V, 30W, and the three-phase output terminal block 51, which outputs three-phase AC from the generator body 2 to the three-phase load L1 connected to the three-phase output terminal block 51. In addition, a single-phase AC output system 1φ is formed by the 20U, 20W, 20V' of the main output circuit, the single-phase output circuit 40U, 40V', 40W, and the single-phase output terminal block 52, which outputs single-phase AC from the generator body 2 to the single-phase loads L2, L3, L4 connected to the single-phase output terminal block 52.

[0072] This single-phase AC output system 1φ is a high-voltage single-phase AC output system 1φ capable of outputting single-phase AC at the same voltage as three-phase AC voltage (for example, single-phase 220V). U-W This system outputs a single-phase AC voltage (for example, 110V single-phase) at a predetermined lower voltage than the three-phase AC voltage, and consists of multiple low-voltage single-phase AC output systems (1φ). U-V’ ,1φ W-V’ A system is in place.

[0073] Of these, there is a high-voltage single-phase AC output system (220V single-phase AC output system) 1φ U-W It consists of the 20U and 20W main output circuits, the 40U and 40W single-phase output circuits, and the U2 and W2 output terminals of the single-phase output terminal block 52.

[0074] Also, one of the low-voltage single-phase AC output systems (110V single-phase AC output systems) is 1φ U-V’ It consists of 20U and 20V' of the main output circuit, 40U and 40V' of the single-phase output circuit, and output terminals U2 and V2 of the single-phase output terminal block 52, as well as the other 1φ of the low-voltage single-phase AC output system. W-V’ It consists of 20W, 20V' from the main output circuit, 40W, 40V' from the single-phase output circuit, and output terminals W2, V2 of the single-phase output terminal block 52.

[0075] In the illustrated embodiment, a three-phase circuit breaker 31 is further provided in the three-phase output circuits 30U, 30V, and 30W, and a single-phase circuit breaker 41 is provided in the single-phase output circuits 40U, 40V', and 40W. This allows the three-phase circuit breaker 31 and the single-phase circuit breaker 41 to be operated to start / stop the power supply to the three-phase load L1 and the single-phase loads L2 to L4.

[0076] [Remaining capacity display device] (1) Overall configuration of the remaining capacity display device The remaining capacity display device 60 of the present invention, mounted on the AC generator 1 configured as described above, includes, as shown in Figure 1, voltage detection means 61U, 61V, 61W, 61V', 61N for detecting the instantaneous voltage V of the three-phase AC output system 3φ and the single-phase AC output system 1φ, and current detection means 62U, 62V, 62W, 62U2, 62V', 62W2 for detecting the instantaneous current I. Based on the instantaneous voltage and current V and I detected by the voltage detection means 61U, 61V, 61W, 61V', 61N and the current detection means 62U, 62V, 62W, 62U2, 62V', 62W2, the remaining capacity P of the generator body 2 is displayed according to a pre-stored program. remain A control device (controller) 70 consisting of a microcontroller or the like that calculates [kW], and the remaining capacity P calculated by the control device (controller) 70. remain It is equipped with a display means 80, such as a monitor screen, that displays [kW].

[0077] (2) Voltage detection means and current detection means The aforementioned voltage detection means 61U, 61V, 61W, 61V', and 61N perform voltage detection processing to sequentially detect the instantaneous value V of the voltage of the three-phase AC output system 3φ and the single-phase AC output system 1φ, respectively, and output the detected voltage to the controller 70.

[0078] In the illustrated embodiment, the voltage detection means (voltage detector) 61N is connected to the neutral point N of the generator body 2, and other voltage detection means (voltage detectors) 61U, 61V, 61W, 61V' are provided on the main output circuits 20U, 20V, 20W, 20V', thereby detecting the instantaneous value V of the voltage (potential difference) between the neutral point N of the generator body 2 and each phase U, V, W. U ,V V ,V W And the instantaneous value V of the voltage (potential difference) between the neutral point N and the auxiliary winding V'. V’ It is designed to detect each of them individually.

[0079] The voltages of the three-phase output circuit 30U and the single-phase output circuit 40U connected to the U-phase of the generator body 2 are both equal to the voltage V of the U-phase of the generator body 2. UThe voltages of the 30W three-phase output circuit and the 40W single-phase output circuit connected to the W phase of the generator body 2 are the same as the W phase voltage V of the generator body 2. W This will have the same value.

[0080] Furthermore, the voltage of the three-phase output circuit 30V connected to the V phase of the generator body 2 is equal to the voltage of the V phase of the generator body 2. V As a result, the voltage of the single-phase output circuit 40V' connected to the auxiliary winding V' of the generator body 2 is the same as the voltage of the auxiliary winding V'. V’ This is equivalent to the above.

[0081] Therefore, a voltage detector is installed at the above location to measure the voltage between each phase U, V, and W of the generator body 2 and the auxiliary winding V'. U ,V V ,V W By detecting these, it is possible to detect the voltages of the three-phase output circuits 30U, 30V, and 30W that constitute the three-phase AC output system 3φ, and the voltages of the single-phase output circuits 40U, 40V', and 40W that constitute the single-phase AC output system 1φ.

[0082] Furthermore, among the current detection means mentioned above, 62U, 62V, and 62W detect the instantaneous value of the current of the three-phase output circuits 30U, 30V, and 30W that constitute the three-phase AC output system 3φ. 3φU ,I 3φV ,I 3φW Furthermore, the current detection means 62U2, 62V', and 62W2 detect the instantaneous value of the current of the single-phase output circuits 40U, 40V', and 40W that constitute the single-phase AC output system 1φ. 1φU ,I 1φV’ ,I 1φW A current detection process is executed to sequentially detect each of these currents, and the instantaneous value I of the detected current is output to the controller 70.

[0083] (3) Controller The instantaneous value V of the voltage detected sequentially by the aforementioned voltage detection means 61U, 61V, 61W, 61V', 61N. U ,V V ,V W ,V V’And the instantaneous value I of the current sequentially detected by the current detection means 62U, 62V, 62W, 62U2, 62V', 62W2 3φU ,I 3φV ,I 3φW ,I 1φU ,I 1φV’ ,I 1φW The output is sent to the controller 70, and upon receiving the instantaneous values ​​of voltage and current, the controller 70, according to a pre-stored program, activates the following means to calculate the remaining capacity of the three-phase AC output system 3φ and the single-phase AC output system 1φ provided on the AC generator 1.

[0084] (3-1) Means for calculating available power The active power calculation means 71 calculates the instantaneous value V of the voltage detected by the voltage detection means 61U, 61V, 61W, 61V', 61N. U ,V V ,V W ,V V’ And the instantaneous value I of the current detected by the current detection means 62U, 62V, 62W, 62U2, 62V', 62W2 3φU ,I 3φV ,I 3φW ,I 1φU ,I 1φV’ ,I 1φW Based on this, the process for calculating the active power used, P[kW], is executed.

[0085] This active power P [kW] represents the power consumed by loads L1 to L4 at the time of detection of the instantaneous voltage V and instantaneous current I, expressed as an active power value [kW].

[0086] The calculation of the active power used P [kW] is based on the instantaneous voltage V detected by the voltage detection means 61U, 61V, 61W, 61V', 61N. U ,V V ,V W ,V V’ And the instantaneous value I of the current detected by the current detection means 62U, 62V, 62W, 62U2, 62V', 62W2 3φU ,I 3φV ,I 3φW ,I 1φU ,I 1φV’ ,I1φW It can be calculated by integrating the product of these terms and averaging it over one period.

[0087] The active power calculation means 71 uses the active power P as follows: • Active power used by each of the 3φ phases of a three-phase AC output system (P) 3φU ,P 3φV ,P 3φW ), • Total active power used by the three-phase AC output system (P) 3φ ), • Active power used by each phase of a single-phase AC output system (P) 1φU ,P 1φV’ ,P 1φW ), • Total active power used by the single-phase AC output system (P) 1φ ), • High-voltage single-phase AC output system 1φ U-W Power used (P 1φU-W ), • Low voltage single-phase AC output system 1 φU-V’ ,1φ W-V’ Each active power used (P 1φU-V’ ,P 1φW-V’ ), • Active power used by each phase (P) of the U, V, and W of the generator unit 2 U ,P V ,P W ) and the active power (P) used by the auxiliary winding V' V’ ), and, • Calculate the total active power (P) used by the entire generator unit 2.

[0088] (3-1-1) Calculation of the active power used in a three-phase AC output system The active power used by each phase of a three-phase AC output system (P) 3φU ,P 3φV ,P 3φW ) can be calculated using the following formula.

number

[0089] The active power calculation means 71 then calculates the active power (P) of each phase of the three-phase AC output system 3φ obtained above.3φU ,P 3φV ,P 3φW Using ), the total active power P of the three-phase AC output system 3φ is used. 3φ The following equation, P 3φ =P 3φU +P 3φV +P 3φW It is calculated by [method].

[0090] (3-1-2) Calculation of the active power used by a single-phase AC output system The active power calculation means 71 calculates the active power (P) of each phase of the single-phase AC output system 1φ. 1φU ,P 1φV’ ,P 1φW ) is calculated using the following formula.

number

[0091] The active power calculation means 71 then calculates the active power (P) of each phase of the single-phase AC output system 1φ obtained above. 1φU ,P 1φV’ ,P 1φW Using ), the total active power P of the single-phase AC output system 1φ is used. 1φ The following equation, P 1φ =P 1φU +P 1φV’ +P 1φW It is calculated by [method].

[0092] Furthermore, the active power calculation means 71 calculates the high-voltage single-phase AC output system 1φ from the single-phase AC output system 1φ. U-W Power used (P 1φU-W ) and a low-voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ Power used (P 1φU-V’ ,P 1φW-V’ ) is given by the following equation, P 1φU-W =P 1φU +P 1φW P 1φU-V’ =P 1φU +P 1φV’ P 1φW-V’ =P 1φW +P 1φV’ It is calculated by [method].

[0093] (3-1-3) Calculation of the active power used by the generator itself The available power calculation means 71 further calculates the available power P of each of the U, V, and W phases of the generator body 2. U ,P V ,P W And, the auxiliary winding V' is used for active power P. V’ , and the total usable active power P of the generator body 2 are given by the following equations, P U =P 3φU +P 1φU P V =P 3φV P W =P 3φW +P 1φW P V’ =P 1φV’ P=(P 3φU +P 3φV +P 3φW )+(P 1φU +P 1φV’ +P 1φW )=P 3φ +P 1φ It is calculated by [method].

[0094] (3-2) Means for calculating apparent power usage The apparent power calculation means 72 calculates the effective value of the voltage V based on the instantaneous value V of the voltage detected by the voltage detection means 61U, 61V, 61W, 61V', 61N. rms In addition to calculating the effective value I of the current, based on the instantaneous value I of the current detected by the current detection means 62U, 62V, 62W, 62U2, 62V', 62W2, the effective value I of the current is calculated. rms Calculate the effective value V of the calculated voltage. rms and the effective value of the current I rmsBased on this, an apparent power calculation process is performed to calculate the apparent power used S [kVA], which is the apparent power used by the three-phase AC output system 3φ and the single-phase AC output system 1φ at the time of detection of the instantaneous voltage V and the instantaneous current I, expressed as an apparent power value [kVA].

[0095] (3-2-1) Calculation of RMS values ​​of voltage and current The apparent power calculation means 72 calculates the instantaneous voltage V of the U, V, W phases of the generator body 2 and the auxiliary winding V' as detected by the voltage detection means 61U, 61V, 61W, 61V', 61N, as shown in the following equation. U ,V V ,V W ,V V’ The root mean square (RMS) over one period is the effective value of the U-phase voltage V. rms U , the effective value of the V-phase voltage V rms V The effective value of the W phase voltage V rms W , and the effective value V of the auxiliary winding V' rms V’ It is calculated as follows.

number

[0096] Furthermore, the apparent power calculation means 72 calculates the instantaneous value I of the current detected by the current detection means 62U, 62V, 62W, 62U2, 62V', 62W2. 3φU ,I 3φV ,I 3φW ,I 1φU ,I 1φV’ ,I 1φW The effective value I of the current in the three-phase output circuit 30U is calculated as the root mean square (RMS) over one period. rms 3φU , the effective value of the current in a 30V three-phase output circuit I rms 3φV , the effective value of the current of a 30W three-phase output circuit I rms 3φW And the effective value of the current in the single-phase output circuit 40U I rms 1φU , the effective value of the current in a single-phase output circuit of 40V' I rms 1φV’ , and, the effective value of the current of the single-phase output circuit 40W I rms 1φW These are expressed as follows:

number

[0097] Then, the apparent power calculation means 72 calculates the effective value I of the currents of each phase U, V, and W of the generator body from the calculation results. rms U ,I rms V ,I rms W And, the effective value I of the current in the auxiliary winding V'. rms V’ These are expressed as follows: I rms U =I rms 3φU +I rms 1φU I rms V =I rms 3φV I rms W =I rms 3φW +I rms 1φW I rms V’ =I rms 1φV’ It is calculated by [method].

[0098] (3-2-2) Calculation of apparent power used The apparent power calculation means 72 uses the effective value V of the voltage calculated above. rms and the effective value of the current I rms Using, • Apparent power consumption (S) of each phase of a three-phase AC output system (3φ) 3φU ,S 3φV ,S 3φW ), ·Apparent power usage (S 3φ ), • Apparent power consumption (S) of each phase in a single-phase AC output system (1φ) 1φU ,S 1φV’ ,S 1φW ), • Apparent power consumption of the entire single-phase AC output system (S) 1φ ), • High-voltage single-phase AC output system 1φ U-W Apparent power used (S 1φU-W ), • Low-voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ Each apparent power consumption (S 1φU-V’ ,S 1φW-V’ ), • Apparent power (S) used by each of the U, V, and W phases of the generator body 2 and the auxiliary winding V'. U ,S V ,S W ,S V’ ), and, • Calculate the apparent power (S) used by the entire generator unit 2.

[0099] (3-2-2-1) Calculation of apparent power used in a three-phase AC output system The apparent power usage calculation means 72 calculates the apparent power usage (S) of each phase of the three-phase AC output system 3φ. 3φU ,S 3φV ,S 3φW ) and the apparent power used by the entire three-phase AC output system (S 3φ ) is given by the following equation, S 3φU =V rms U ×I rms 3φU S 3φV =V rms V ×I rms 3φV S 3φW =V rms W ×I rms 3φW S 3φ =S 3φU +S 3φV +S 3φW It is calculated by [method].

[0100] (3-2-2-2) Calculation of apparent power used in a single-phase AC output system The apparent power usage calculation means 72 calculates the apparent power usage (S) of each phase of the single-phase AC output system 1φ. 1φU ,S 1φV’ ,S 1φW ) and, high-voltage single-phase AC output system 1φ U-W Apparent power used (S 1φU-W ), Low voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ Apparent power used (S 1φU-V’ ,S 1φW-V’ ), and the apparent power used by the entire single-phase AC output system 1φ (S 1φ ) are expressed as follows, S 1φU =V rms U ×I rms 1φU S 1φV’ =V rms V’ ×I rms 1φV’ S 1φW =V rms W ×I rms 1φW S 1φU-W =S 1φU +S 1φW S 1φU-V’ =S 1φU +S 1φV’ S 1φW-V’ =S 1φW +S 1φV’ S 1φ =S 1φU +S 1φV’ +S 1φW It is calculated by [method].

[0101] (3-2-2-3) Calculation of apparent power used by the generator itself The apparent power usage calculation means 72 calculates the apparent power usage (S) of each phase U, V, and W of the generator body 2 and the auxiliary winding V'. U ,S V ,S W ,S V The apparent power (S) used by the entire generator body 2 is given by the following equations: S U =S 3φU +S 1φU S V =S 3φV S W =S 3φW +S 1φW S V’ =S 1φV’ S=(S 3φU +S 3φV +S 3φW )+(S 1φU +S 1φV’ +S 1φW )=S 3φ +S 1φ It is calculated by [method].

[0102] (3-3) Power factor calculation means The power factor calculation means 73 performs a power factor calculation process in which it calculates the power factor PF (PF=P / S) at the time of detection of the instantaneous voltage and instantaneous current values ​​by taking the ratio (P / S) of the active power used P [kW] calculated by the active power used calculation means 71 and the apparent power used S [kVA] calculated by the apparent power used calculation means 72 as the power factor PF.

[0103] The power factor PF calculated in this way represents the power factor of the connected load when a load is connected to the output terminal blocks 51 and 52.

[0104] In this embodiment, the power factor is defined as the overall power factor (PF) of the generator body 2 and the power factor (PF) of each phase of the generator body 2. U ,PF V ,PF W ), power factor (PF) of a three-phase AC output system 3φ 3φ ), and the power factor (PF) of the single-phase AC output system 1φ 1φ ) are expressed as follows, PF = P / S PF U =P U / S U PF V =P V / S V PF W =P W / S W PF 3φ =P 3φ / S 3φ PF 1φ =P 1φ / S 1φ It is calculated by [method].

[0105] (3-4) Means for calculating rated active power The rated active power calculation means 74 corrects the generator rated output Pr, which is previously stored in the storage means 75 as, for example, an apparent power value [kVA], to a value corresponding to the power factor PF at the time of detection calculated by the power factor calculation means 73, and this corrects the value to determine the rated active power Pr. active The rated active power calculation process is executed, which is calculated as [kW].

[0106] In this embodiment, the rated active power Pr active [kW] is the rated active power Pr of the entire generator unit 2. active In addition to calculating the rated active power (Pr) of each phase (U phase, V phase, W phase) U active ,Pr V active ,Pr W active ) and the power factor PF of the U phase U , power factor PF of the V phase V Power factor PF of the W phase W It is calculated using the following formula. Pr active =Pr×PF Pr U active =(Pr / 3)×PF U Pr V active =(Pr / 3)×PF V Pr W active =(Pr / 3)×PF W

[0107] The rated active power Pr of the entire generator body 2 calculated by the rated active power calculation means 74 active For example, the calculation of [kW] may be done by storing the generator's rated output Pr as an apparent power value [kVA] in the storage means 75, and then simply calculating it as the product of this generator's rated output Pr and the power factor PF of the entire generator body 2 calculated by the power factor calculation means 73.

[0108] However, in this embodiment, as shown in Figure 4, if the power factor PF of the entire generator body 2 calculated by the power factor calculation means 73 is less than 0.8, the rated output Pr [kVA] of the generator is multiplied directly by the power factor PF calculated by the power factor calculation means 73 to obtain the rated active power Pr active The power factor [kW] is calculated, but if the power factor PF calculated by the power factor calculation means 73 is 0.8 or higher, the rated output Pr [kVA] of the generator is uniformly multiplied by 0.8 to obtain the rated active power Pr active [kW] is being calculated.

[0109] This configuration was adopted because the remaining capacity display device 60 of this embodiment is applied to an AC generator 1 in which a generator body 2 with a generator rated output Pr of 45 kVA is driven by an engine with a rated output of 42.5 kW, and as shown in Figure 5, the rated active power Pr of the entire generator body 2 active To ensure that the [kW] does not exceed the engine's rated output (42.5kW) and caps out at 36[kW], the rated current value Ir is lowered to maintain a constant power factor PF of 0.8 when the power factor PF is 0.8 or higher.

[0110] With this configuration, the remaining capacity P calculated by the remaining capacity calculation means 76 described later is remain By connecting a new load within the specified range, the rated active power Pr of the generator unit 2 will increase. active This not only prevents the connected load from exceeding [kW], but also prevents the connected load from exceeding the engine's rated output (42.5kW).

[0111] However, in the case of AC generator 1, where the engine's rated output [kW] is sufficiently large compared to the value obtained by multiplying the generator's rated output Pr [kVA] by a power factor of "1", there is no need to set such an upper limit on the power factor PF.

[0112] (3-5) Remaining capacity calculation method The remaining capacity calculation means 76 calculates the rated active power Pr of the generator body 2 calculated by the rated active power calculation means 74. active Using [kW] and the active power P[kW] of the generator body 2 calculated by the active power calculation means 71, the remaining capacity of the three-phase AC output system 3φ and the high-voltage single-phase AC output system 1φ are calculated. U-W The remaining capacity in each low-voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ Calculate the remaining capacity of each.

[0113] Each output system 3φ, 1φ (1φ U-W ,1φ U-V’ ,1φ W-V’ In calculating the remaining capacity, the remaining capacity calculation means 76 calculates the rated active power Pr of the U-phase calculated by the rated active power calculation means 74.U active [kW], V-phase rated active power Pr V active [kW] and the rated active power Pr of the W phase W active [kW] and the U-phase active power P calculated by the active power calculation means 71. U [kW], V-phase active power P V [kW] and the active power P used for the W phase. W Using [kW], the remaining capacity P of the U phase U remain V-phase remaining capacity P V remain , and the remaining capacity P of the W phase W remain The following equations apply to each of them. P U remain =Pr U active -(P 3φU +P 1φU )=Pr U active -P U P V remain =Pr V active -(P 3φV +P 1φV )=Pr V active -P V P W remain =Pr W active -(P 3φW +P 1φW )=Pr W active -P W It is calculated by [method].

[0114] Then, the remaining capacity calculation means 76 calculates the remaining capacity P of the U phase. U remain V-phase remaining capacity P V remain , and the remaining capacity P of the W phase W remain Of these, the smallest value is multiplied by 3 to obtain the remaining capacity P of the entire generator body 2. remain The remaining capacity P that can be extracted from the three-phase AC output system 3φ is 3φremain The following equation P 3φ remain =P remain =MIN[(P U remain ) or (P V remain ) or (P W remain )〕×3 It is calculated as follows.

[0115] Thus, the remaining capacity P of the three-phase AC output system 3φ3φ remain The remaining capacity of each phase (P U remain ,P V remain ,P W remain By multiplying the smallest value among them by 3, even when the remaining capacity of some phases is lower than that of other phases, such as when power is supplied to both three-phase and single-phase loads simultaneously, the remaining capacity P of the three-phase AC output system 3φ is calculated based on the phase with the lowest remaining capacity. 3φ remain By calculating the remaining capacity P 3φ remain By connecting an additional three-phase load within the specified range, overcurrents can be prevented.

[0116] Furthermore, the remaining capacity calculation means is a low-voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ Remaining capacity P 1φU-V’ remain ,P 1φW-V’ remain The following equations apply to each of them: P 1φU-V’ remain =Pr U active -(P 3φU +P 1φU )=Pr U active -P U P 1φW-V’remain =Pr W active -(P 3φW +P 1φW )=Pr W active -P W It is calculated by [method].

[0117] Furthermore, the remaining capacity calculation means 76 calculates the remaining capacity P of the U phase of the generator body 2 as shown in the following equation. U remain , or remaining capacity P of the W phase W remain Of these, the smaller value is doubled to form a high-voltage single-phase AC output system 1φ U-W Remaining capacity P 1φU-W remain It is calculated as follows. P 1φU-W remain =MIN[(P U remain ) or (P W remain )〕×2

[0118] (3-6) Other (Means for calculating residual current value) Furthermore, the controller 70 detects the instantaneous voltage V and the instantaneous current I, and the remaining current I that can be extracted from the generator body 2 at that time. remain A means 77 for calculating the remaining current value may also be provided.

[0119] This residual current value I remain As such, the aforementioned residual current value calculation means 77 calculates the residual current value I of the three-phase AC output system 3φ. 3φ remain Low voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ Each remaining current value I 1φ U-V’ remain ,I 1φ W-V’ remain , and high-voltage single-phase AC output system 1φ U-W The remaining current value I 1φ U-W remain Calculate each of them.

[0120] The remaining current value calculation means 77 calculates these remaining current values ​​(I 3φ remain ,I 1φ U-V’ remain ,I 1φ W-V’ remain ,I 1φ U-W remain In calculating the power factor, the rated current value Ir of the generator body 2, which is stored in the memory means, and the power factor PF of the entire generator body 2 calculated by the power factor calculation means 73 are used to calculate the rated effective current value Ir of each phase of the generator body 2. U active ,Ir V active ,Ir W active The following equation Ir U active =Ir V active =Ir W active =Ir×PF It is calculated by [method].

[0121] The following is the current value I 3φ U working ,I 3φ V working ,I 3φ W working ,I 1φ U working ,I 1φ W working This is the instantaneous value I of the current detected by the current detection means 62U, 62V, 62W, 62U2, and 62W2. 3φU ,I 3φV ,I 3φW ,I 1φU ,I 1φW The effective value of the current calculated from this is I rms3φU ,I rms3φV ,I rms3φW ,I rms1φU ,Irms1φW We define and explain it as being the same as [the other term].

[0122] Furthermore, the residual current value calculation means 77 calculates the rated effective current value Ir of the U-phase, V-phase, and W-phase of the generator body 2. U active ,Ir V active ,Ir W active And, the current value I of the three-phase output circuit 30U, 30V, 30W 3φU working ,I 3φV working ,I 3φW working , Single-phase output circuit 40U, 40W current value I 1φU working ,I 1φW working Using this, the remaining current values ​​I of each phase U, V, and W of the generator body 2 are calculated. U remain ,I V remain ,I W remain These are expressed as follows: I U remain =Ir U active -(I 3φU working +I 1φU working ) I V remain =Ir V active -I 3φU working I W remain =Ir W active -(I 3φW working +I 1φW working ) It is calculated by [method].

[0123] Then, as shown in the following equation, the residual current values ​​I of the U, V, and W phases of the generator body 2 U remain ,I V remain ,I W remain The minimum value among them is the residual current value I of the three-phase AC output system 3φ. 3φ remain Let's assume that. I 3φ remain =MIN(I U remain OR I V remain OR I W remain )

[0124] Furthermore, as shown in the following equation, the residual current value I of the U phase of the generator body 2 U remain One low-voltage single-phase AC output system 1φ U-V’ The remaining current value I 1φ U-V’ remain Assuming the remaining current value of the W phase is I W remain to the other low-voltage single-phase AC output system 1φ W-V’The remaining current value I 1φ W-V’ remain This also results in the remaining current value I of the U phase. U remain and the remaining current value I of the W phase W remain Of these, the smaller one is used for the high-voltage single-phase AC output system 1φ U-W The remaining current value I 1φ U-W remain It is calculated as follows. I 1φU-V’ remain =I U remain I 1φW-V’ remain =I W remain I 1φU-W remain =MIN(I U remain OR I W remain )

[0125] (4)Display means As shown in Figure 1, the remaining capacity display device 60 of the present invention displays the remaining capacity P of the three-phase AC output system 3φ calculated by the remaining capacity calculation means 76 of the controller 70 described above. 3φ remain Low voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ Remaining capacity P 1φU-V’ remain ,P 1φW-V’ remain And, a high-voltage single-phase AC output system 1φ U-W Remaining capacity P 1φU-W remain A display means 80, such as a monitor screen, is provided to display the information.

[0126] Furthermore, in the illustrated example, the remaining capacity calculation means 76 calculates the three-phase AC output system 3φ and the single-phase AC output system 1φ (1φ U-W ,1φ U-V’ ,1φ W-V’ ) Remaining capacity P 3φ remain ,P 1φU-W remain ,P 1φU-V’ remain ,P 1φW-V’ remain Along with this, the remaining current value I of the three-phase AC output system 3φ calculated by the aforementioned remaining current value calculation means 77 3φ remain Low voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ The remaining current value I 1φU-V’ remain ,I 1φW-V’ remain , and high-voltage single-phase AC output system 1φ U-W The remaining current value I 1φU-W remainBy also displaying this information, users can now refer to not only the remaining capacity but also the remaining current value when connecting a load.

[0127] Note that the illustrated example shows a screen display when no load is connected to either the three-phase output terminal block 51 or the single-phase output terminal block 52. The display screen shows the rated active power Pr of the generator body 2. active The 36kW output and the rated current value Ir of the generator body 2, which is 118.0A, are the remaining capacity P of the three-phase AC output system 3φ. 3φ remain and remaining current value I 3φ remain This is displayed as such, and the user can refer to this display when connecting the three-phase load L1.

[0128] Furthermore, the rated active power P of the U-phase and W-phase of the generator body 2 U active ,P V active The kW is 13.0kW, and the rated current value (Ir U =Ir W 118.0A (=Ir) is used in a low-voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ Remaining capacity P of loads L2 and L3 that can be connected 1φU-V’ remain ,P 1φW-V’ remain and remaining current value I 1φU-V’ remain ,I 1φW-V’ remain This is displayed as such, and users can refer to this display when connecting single-phase loads L2 and L3.

[0129] Furthermore, a low-voltage single-phase AC output system 1φ U-V’ ,1φ W-V’ Remaining capacity P 1φ U-V’ remain ,P 1φ W-V’ remain The smaller of the two values ​​is twice the value, which is 26.0kW and the rated current value (Ir U =Ir W 118.0A, where =Ir, is used in a high-voltage single-phase AC output system 1φ U-W Remaining capacity P 1φU-W remain This is displayed as such, and users can refer to this display when connecting the single-phase load L4.

[0130] [Variation] Figure 2 shows another example configuration of the AC generator 1 equipped with the remaining capacity display device 60 of the present invention.

[0131] The AC generator 1 shown in Figure 1 was equipped with a generator body 2 that had an auxiliary winding V' in addition to the U, V, and W phase windings, but the AC generator 1 shown in Figure 2 is equipped with a generator body 2 that does not have an auxiliary winding, and has intermediate taps U2 and W2 on the U winding and W winding, respectively.

[0132] The output terminals u, v, and w of the U, V, and W phases of the generator body 2 are connected to the three-phase output terminal block 51 via the three-phase output circuits 30U, 30V, and 30W. The output terminal n connected to the neutral point N of the generator body 2 and the intermediate taps U2 and W2 are connected to the single-phase output terminal block 52 via the single-phase output circuits 40U2, 40N, and 40W2.

[0133] Therefore, the aforementioned three-phase output circuits 30U, 30V, 30W and the three-phase output terminal block 51 form a three-phase AC output system 3φ that outputs three-phase AC from the generator body 2 to a three-phase load L1, while the single-phase output circuits 40U2, 40N, 40W2 and the single-phase output terminal block 52 form a single-phase AC output system 1φ that outputs single-phase AC from the generator body 2 to single-phase loads L2, L3.

[0134] This single-phase AC output system 1φ is provided by single-phase output circuits 40U2, 40N and terminals U2, N of the single-phase output terminal block 52 connected thereto, thereby providing one low-voltage single-phase AC output system 1φ U2-N A low-voltage single-phase AC output system 1φ is formed, and this low-voltage single-phase AC output system 1φ U2-N The system is configured to output a single-phase AC voltage (for example, 110V) that is predetermined to be lower than the voltage of the three-phase output to a single-phase load L2.

[0135] Furthermore, the single-phase output circuits 41W2 and 41N and the terminals W2 and N of the single-phase output terminal block 52 connected thereto, connect to the other low-voltage single-phase AC output system 1φ W2-N A low-voltage single-phase AC output system 1φ is formed, and this low-voltage single-phase AC output system 1φ W2-NThe system is configured to output a predetermined low voltage (for example, 110V) of single-phase AC to a single-phase load L3 via this connection.

[0136] Furthermore, as a voltage detection means, in addition to the voltage detectors 61U, 61V, and 61W connected to the U, V, and W phases of the generator body 2, and the voltage detector 61N connected to the neutral point N, voltage detectors 61U2 and 61W2 connected to the intermediate taps U2 and W2 respectively are provided, so that the voltage (potential difference with the neutral point N) between the neutral point N of the generator body 2, each of the U, V, and W phases, and between the intermediate taps U2 and W2 can be detected.

[0137] Furthermore, as current detection means, current detectors 62U, 62V, and 62W are provided to detect the current of the three-phase output circuits 30U, 30V, and 30W, and current detectors 62U2 and 62W2 are provided to detect the current of the single-phase output circuits 40U2 and 40W2, respectively.

[0138] In this configuration, the controller 70, which receives the instantaneous voltage and current values ​​V and I detected by the voltage detection means 61U, 61V, 61W, 61N, 61U2, 61W2 and current detection means 62U, 62V, 62W, 62U2, 62W2, activates the active power calculation means 71, apparent power calculation means 72, power factor calculation means 73, rated active power calculation means 74, remaining capacity calculation means 76, and remaining current value calculation means 77, and as an example, calculates the active power P, apparent power S, power factor PF, and rated active power Pr as follows. active ,Remaining capacity P remain , and residual current value I remain Calculate.

[0139] (1) Calculation of available power The controller 70's active power calculation means 71 calculates the instantaneous voltage V of each phase U, V, and W, which is detected as the potential difference between the voltage detection means 61N connected to the neutral point N of the generator body 2 and the voltage detection means 61U, 61V, 61W, 61U2, 61W2 connected to each phase U, V, and W and the intermediate taps U2, W2. U ,V V ,V W, and the instantaneous value V of the voltage at the intermediate taps U2,W2 U2 ,V W2 The instantaneous value I of the current of the three-phase output circuits 30U, 30V, 30W and the single-phase output circuits 40U2, 40W2 detected by the current detection means 62U, 62V, 62W, 62U2, 62W2 3φU ,I 3φV ,I 3φW ,I 1φU2 ,I 1φW2 The following active power consumption P is calculated using the provided method. • Active power used by each of the 3φ phases of a three-phase AC output system (P) 3φU ,P 3φV ,P 3φW ), • Total active power used by the three-phase AC output system (P) 3φ ), • Single-phase output circuit 40U2, 40W2: Usable active power (P 1φU2 ,P 1φW2 ), • Active power used by each phase (P) of the U, V, and W of the generator unit 2 U ,P V ,P W ), and, • Total available power (P) for the entire generator unit 2.

[0140] (1-1) Calculation of the active power used by a three-phase AC output system The active power used by each phase of a three-phase AC output system (P) 3φU ,P 3φV ,P 3φW The calculation of the voltage (potential difference with the neutral point N) is the same as in the case of AC generator 1 explained with reference to Figure 1, and is the instantaneous value V of the voltage (potential difference with the neutral point N) of each phase U, V, and W detected by the voltage detection means 61N and voltage detection means 61U, 61V, and 61W. U ,V V ,V W The instantaneous value I of the current of the three-phase output circuit 30U, 30V, 30W detected by the current detection means 62U, 62V, 62W 3φU ,I 3φV ,I 3φW It can be obtained by integrating the product of over one period, and can be calculated using the formula shown in [Equation 1] above.

[0141] Then, the active power used by each phase of the three-phase AC output system 3φ obtained (P 3φU ,P 3φV ,P 3φW Using ), the total active power P of the three-phase AC output system 3φ is used. 3φ The following equation P 3φ =P 3φU +P 3φV +P 3φW It is calculated by [method].

[0142] (1-2) Calculation of the active power used by the single-phase output circuits 40U2 and 40W2 The amount of power consumed via the single-phase output circuits 40U2 and 40W2 connected to the intermediate taps U2 and W2 is expressed as the active power value [kW]. 1φU2 ,P 1φW2 ) is the instantaneous value of the voltage detected as the potential difference between voltage detector 61N and voltage detectors 61U2, 61W2 V U2 ,V W2 And the instantaneous value I of the current of the single-phase output circuits 40U2 and 40W2 detected by the current detection means 62U2 and 62W2 1φU2 ,I 1φW2 Using the following formula

number

[0143] (1-3) Calculation of the active power used by the generator itself The available power calculation means 71 further calculates the available power P of each of the U, V, and W phases of the generator body 2. U ,P V ,P W The total usable power P of the generator body 2 is given by the following equations, P U =P 3φU +P 1φU2 P V =P 3φV P W =P 3φW +P 1φW2 P=P 3φU +P3φV +P 3φW +P 1φU2 +P 1φW2 It is calculated by [method].

[0144] (2) Calculation of apparent power used The apparent power calculation means 72 uses the instantaneous value V of the voltage detected by the voltage detection means 61U, 61V, 61W, 61N, 61U2, 61W2. U ,V V ,V W ,V U2 ,V W2 Based on this, the effective value of the voltage V rms U ,V rms V ,V rms W ,V rms U2 ,V rms W2 In addition to calculating the instantaneous value I of the current detected by the current detection means 62U, 62V, 62W, 62U2, and 62W2, 3φU ,I 3φV ,I 3φW ,I 1φU2 ,I 1φW2 Based on this, the effective value of the current I rms 3φU ,I rms 3φV ,I rms 3φW ,I rms 1φU2 ,I rms 1φW2 Calculate the effective value of the voltage and the effective value of the current, • Apparent power consumption (S) of each phase of a three-phase AC output system (3φ) 3φU ,S 3φV ,S 3φW ), ·Apparent power usage (S 3φ ), • Apparent power (S) used in single-phase output circuits 40U2, 40W2 1φU2 ,S 1φW2 ), • Apparent power consumption (S) of each phase U, V, and W of the generator unit 2 U ,S V ,S W ), and, • Calculate the apparent power (S) used by the entire generator unit 2.

[0145] (2-1) Calculation of apparent power used in a three-phase AC output system The apparent power usage calculation means 72 calculates the apparent power usage (S) of each phase of the three-phase AC output system 3φ. 3φU ,S 3φV ,S 3φW ) and the apparent power used by the entire three-phase AC output system (S 3φ ) is given by the following equation, S 3φU =V rms U ×I rms 3φU S 3φV =V rms V ×I rms 3φV S 3φW =V rms W ×I rms 3φW S 3φ =S 3φU +S 3φV +S 3φW

[0146] (2-2) Calculation of apparent power used by single-phase output circuits 40U2 and 40W2 The apparent power usage calculation means 72 expresses the power used via the single-phase output circuits 40U2 and 40W2 as an apparent power value [kVA], which is the apparent power usage (S 1φU2 ,S 1φW2 ) is given by the following equation, S 1φU2 =V rms 1φU2 ×I rms 1φU2 S 1φW2 =V rms 1φW2 ×I rms 1φW2 It is calculated by [method].

[0147] (2-3) Calculation of apparent power used by the generator itself The apparent power usage calculation means 72 further calculates the apparent power usage S of the U, V, and W phases of the generator body 2. U ,S V ,S W The apparent power S used by the entire generator body 2 is expressed by the following equations, S U =S 3φU +S 1φU2 S V =S 3φV S W =S3φW +S 1φW2 S=S 3φU +S 3φV +S 3φW +S 1φU2 +S 1φW2 It is calculated by [method].

[0148] (3) Calculation of power factor The power factor calculation means 73 uses the active power used calculated by the active power used calculation means and the apparent power used calculated by the apparent power used calculation means to calculate the overall power factor (PF) of the generator body 2 and the power factor (PF) of each phase of the generator body 2. U ,PF V ,PF W ), power factor (PF) of a three-phase AC output system 3φ 3φ ), and the power factor (PF) of the single-phase output circuits 40U2, 40W2 1φU2 ,PF 1φW2 ) are expressed as follows, PF = P / S PF U =P U / S U PF V =P V / S V PF W =P W / S W PF 3φ =P 3φ / S 3φ PF 1φU2 =P 1φU2 / S 1φU2 PF 1φW2 =P 1φW2 / S 1φW2 It is calculated by [method].

[0149] (4) Calculation of rated active power In this embodiment, the rated active power calculation means 74 calculates the generator rated output Pr (= the generator rated output Pr of a three-phase AC output system 3φ) which is stored in advance in the storage means 75 as an apparent power value [kVA]. 3φ), Generator rated output Pr at intermediate taps U2,W2 1φU2 ,Pr 1φW2 , and the overall power factor (PF) of the generator body 2 calculated by the power factor calculation means 73, and the power factor (PF) of each phase of the generator body 2. U ,PF V ,PF W ), power factor (PF) of a three-phase AC output system 3φ 3φ ), and the power factor (PF) of the single-phase output circuits 40U2, 40W2 1φU2 ,PF 1φW2 Based on this, the total rated active power Pr of the generator body 2 active (=Rated active power Pr of a three-phase AC output system 3φ) 3φ active ) and the rated active power (Pr U active ,Pr V active ,Pr W active ) and the rated active power Pr of the intermediate taps U2 and W2 1φU2 active ,Pr 1φW2 active Calculate each of them. Pr active =Pr×PF Pr U active =(Pr / 3)×PF U Pr V active =(Pr / 3)×PF V Pr W active =(Pr / 3)×PF W Pr 1φU2 active =Pr 1φU2 ×PF 1φU2 Pr 1φW2 active =Pr 1φW2 ×PF 1φW2

[0150] (5) Calculation of remaining capacity The remaining capacity calculation means 76 calculates the rated active power Pr of the generator body 2 calculated by the rated active power calculation means 74. active Using the [kW] and the active power P[kW] of the generator body 2 calculated by the active power calculation means 71, the three-phase AC output system 3φ and the low-voltage single-phase AC output system 1φ are used to determine the three-phase AC output system 3φ and the low-voltage single-phase AC output system 1φ U2-N ,1φ W2-N Calculate the remaining capacity for each active power value [kW].

[0151] Low-voltage single-phase AC output system 1φ U2-N ,1φ W2-N Remaining capacity Pr 1φU2-N remain ,Pr 1φW2-N remain In calculating this, the remaining capacity calculation means 76 calculates the rated active power Pr of the intermediate taps U2 and W2 calculated by the rated active power calculation means 74. 1φU2 active ,Pr 1φW2 active The active power P of the U-phase and W-phase of the three-phase AC output system calculated by the active power calculation means is also calculated. 3φU ,P 3φW And, the effective power P used for the single-phase output circuits 40U2, 40W2 1φU2 ,P 1φW2 Using this method, the remaining capacity Pr can be extracted from the center taps U2 and W2 (single-phase output circuits 40U2 and 40W2). 1φU2 remain ,Pr 1φW2 remain (=Low voltage single-phase AC output system 1φ) U2-N ,1φ W2-N Remaining capacity Pr 1φ U2-N remain ,Pr 1φ W2-N remain ) to the following expression Pr 1φU2 remain =Pr 1φU2-N remain =Pr 1φU2 active -(P 3φU / 2+P 1φU2 ) Pr 1φ W2remain =Pr 1φW2-N remain =Pr 1φW2 active -(P 3φW / 2+P 1φW2 ) It is calculated by [method].

[0152] Note that in the above calculation, the active power P used by the U phase of the three-phase AC output system 3φ is used. 3φU And, W-phase active power P 3φW The calculations are performed assuming that all values ​​are 1 / 2. This is necessary because, as shown in Figure 2, each phase U, V, and W of the generator body 2 is composed of two windings Ua, Ub, Va, Vb, Wa, and Wb connected in parallel, and intermediate taps U2 and W2 are provided on one of these (Ua and Wa in the illustrated example). If each phase of the generator body 2 does not have parallel windings, the active power P of the U phase of the three-phase AC output system is calculated as follows: 3φUAnd, W is the active power used P 3φW The remaining capacity is calculated without dividing any of the values ​​by half. Pr 1φU2 remain =Pr 1φU2 active -(P 3φU +P 1φU2 ) Pr 1φW2 remain =Pr 1φW2 active -(P 3φW +P 1φW2 )

[0153] The remaining capacity calculation means 76 calculates the rated active power Pr of the U phase calculated by the rated active power calculation means 74. U active [kW], V-phase rated active power Pr V active [kW] and the rated active power Pr of the W phase W active [kW] and the U-phase active power P calculated by the active power calculation means 71. U [kW], V-phase active power P V [kW] and the active power P used for the W phase. W Using [kW], the remaining capacity P of the U phase U remain V-phase remaining capacity P V remain , and the remaining capacity P of the W phase W remain The following equations apply to each of them. P U remain ,=Pr U active -(P 3φU +P 1φU2 ) P V remain ,=Pr V active -P 3φV P W remain ,=Pr W active -(P 3φW +P 1φW2 ) It is calculated by [method].

[0154] The remaining capacity calculation means 76 then calculates the low-voltage single-phase AC output system 1φ U2-N ,1φ W2-N Remaining capacity Pr 1φU2-N remain (=Pr 1φU2 remain ),Pr 1φW2-N remain (=Pr 1φW2 remain If any of the values ​​in the equation above is greater than "0", the remaining capacity P of the U phase is as shown in the following equation. U remain V-phase remaining capacity PV remain , and the remaining capacity P of the W phase W remain The remaining capacity P of the three-phase AC output system is calculated by multiplying the smallest of these values ​​by three. 3φ remain It is calculated as follows. P 3φ remain =MIN[(P U remain ) or (P V remain ) or (P W remain )〕×3

[0155] On the other hand, a low-voltage single-phase AC output system 1φ U2-N ,1φ W2-N Remaining capacity Pr 1φ U2-N remain ,Pr 1φW2-N remain If any of the values ​​is less than or equal to "0", the remaining capacity P of the three-phase AC output system 3φ remain Set to "0" (P 3φ remain =0).

[0156] (6) Other (calculation of remaining current value, etc.) Furthermore, in the AC generator 1 with the configuration shown in Figure 2, the residual current value I of the three-phase AC output system 3φ can be determined in the same manner as described for the AC generator 1 described with reference to Figure 1. 3φ remain Each low-voltage single-phase AC output system 1φ U2-N ,1φ W2-N The remaining current value I 1φU2-N remain ,I 1φW2-N remain A means for calculating the remaining current value may also be provided to calculate each of these values.

[0157] Furthermore, a display means 80, such as a monitor screen, is provided to display the remaining capacity and remaining current values ​​calculated above.

[0158] [Effect, etc.] Table 1 below shows the differences in the displayed remaining capacity when the remaining capacity of the entire three-phase system of an AC generator 1, which is equipped with an engine with a rated output of 42.5 kW and a generator body 2 with a rated output Pr of 45 kVA (at 60 Hz), is displayed using the remaining capacity display method of the present invention and the method described in the aforementioned Patent Document 2.

[0159] [Table 1]

[0160] As mentioned above, in the configuration of the comparative example (Patent Document 2), the difference between the generator rated output [kVA] [Table 1 (2)] and the apparent power used [kVA] [Table 1 (5)] is calculated as the remaining capacity [kVA] [Table 1 (7)], The difference between the engine's rated output [kW] [Table 1 (1)] and the active power used [kW] [Table 1 (6)] is calculated as the remaining power [kW]. The remaining capacity of the active power value [kW] is displayed as the smaller of the remaining capacity [kVA] [Table 1 (7)] and the remaining power [kW].

[0161] As a result, depending on the usage conditions, such as in the cases of "Condition 1" and "Condition 3" in Table 1, the sum of the displayed remaining capacity [kW] [Displayed value in (9) of Table 1] and the active power value of the power used [kW] [(6) of Table 1] may exceed the rated active power [kW] of the generator itself [(4) of Table 1]. Even when a new load is connected within the range of the displayed remaining capacity [kW], it is possible that a load exceeding the rated active power [kW] of the generator itself may be connected.

[0162] In this way, if a load exceeding the rated active power [kW] of the generator is connected, the generator will experience an overcurrent, and the AC generator may shut down due to the activation of safety devices to prevent burnout of the armature windings.

[0163] In contrast, the method of the present invention results in a remaining capacity P remain When displaying the active power used P [kW] and the calculated remaining capacity P remain The sum of [kW] and the rated active power Pr of the generator unit 2 is always equal to the rated active power Pr of the generator unit 2. active By matching the [kW] value, it is possible to connect new loads within the calculated remaining capacity range, thereby preventing excessive loads from being connected to the generator itself.

[0164] [Example of modification] (Addition of determination means) In the embodiments described above, as shown in Figures 1 and 2, the remaining capacity is displayed by showing the remaining capacity calculated by the remaining capacity calculation means 76 as a "numerical value." However, in addition to, or instead of, such a numerical display of the remaining capacity, a determination process is performed to determine whether or not it is possible to connect a load that is scheduled to be newly connected, and the result of this determination is displayed on the display means 81 as a display of the remaining capacity.

[0165] In this case, the determination means 78 enclosed by a dashed line in Figure 3 is added to the aforementioned controller 70.

[0166] The determination of whether a newly scheduled load can be connected is made by the remaining capacity P calculated by the remaining capacity calculation means 76. remain Then, compare the remaining capacity P with the active power consumption [kW], which is the power consumption at the active power value of the load to be newly connected. remain Alternatively, the determination of whether connection is possible may be made if the active power consumption [kW] of the newly connected three-phase load is small.

[0167] However, the remaining capacity P calculated by the remaining capacity calculation means 76 remain Since the power factor used in the calculation corresponds to the power factor of the load already connected to the generator body 2, when connecting a new three-phase load with the same power factor as the already connected load, the generator body 2 will not be overloaded by connecting the load within the range of the remaining capacity calculated by the remaining capacity calculation means 76.

[0168] However, when connecting a load with a lower power factor than an already connected load, even if the new three-phase load is connected within the displayed remaining capacity range, the connected load may exceed the rated current value Ir[A] of the generator unit 2.

[0169] Therefore, it is desirable that the determination of whether or not a newly connected load can be connected also takes into consideration the power factor of the load to be connected.

[0170] Therefore, in this embodiment, the determination means 78 provided in the controller 70 is configured to determine whether or not a load can be connected by considering not only the active power consumption [kW] of the three-phase load to be newly connected, but also its power factor.

[0171] To enable such determination, the storage means 75 of the controller 70 stores load information, including the power factor of the load to be newly connected and the active power consumption [kW], which is the power consumption at the active power value.

[0172] This load information may be stored in the storage means 75 by the user entering the load information on the spot according to the instructions on the input screen displayed on the touch panel, or the load information of frequently connected equipment (e.g., submersible pumps) may be stored in the storage means 72 in advance, for example, at the time of factory shipment of the AC generator 1.

[0173] For example, when determining whether a connection is possible based on load information entered by the user, as shown on the right side of Figure 6, the active power consumption in kW and the power factor from the load information entered by the user can be displayed, and whether or not the connection of the load is possible can be indicated by the illumination of either the "NG" lamp or the "OK" lamp.

[0174] Furthermore, when determining whether a new load can be connected based on load information stored in a storage device beforehand, as shown on the left side of Figure 6, a lamp may be provided for each load corresponding to the pre-stored load information, and the determination result may be displayed by lighting up the lamp for a connectable load and turning off the lamp for an unconnectable load.

[0175] In order to have the determination means 78 perform the aforementioned determination process, the determination means 78 is instructed to use the current value I of the total three-phase current of the generator body 2 at the present time, which is calculated by the aforementioned active power usage calculation means 71, from the total active power usage P of the generator body 2. working A current usage value calculation unit 78a that determines the current usage value, The total current value I of the three phases is calculated from the rated current value Ir of the generator body 2. workingSubtract to obtain the residual current value I of the entire three-phase system remain Calculate (I remain =Ir - I working ) in the residual current value calculation unit 78b, and Based on the power factor and the consumed active power of the load scheduled for new connection stored in the storage means 75, calculate the load current value I load which is the current value flowing through the load scheduled for new connection in the load current calculation unit 78c, and Compare the residual current value I remain with the load current value I load , and when the load current value I load is lower than the residual current value I remain (I remain >I load ), provide a comparison and determination unit 78d that determines that the connection of the additional load is possible.

[0176] In addition, as shown in FIG. 3, in the configuration of this embodiment where the residual current value calculation means of the entire generator main body 2 has already been provided in the controller 70, this residual current value calculation means 77 may also serve as the used current value calculation means 78a and the residual current value calculation unit 78b provided in the determination means 体78. remain

[0177] Further, the comparison of the magnitudes of the residual current value I remain and the load current value I load can be performed not only by directly comparing the residual current value I remain with the load current value I load , but also by comparing the sum of the used current value I working of the generator main body 2 and the load current value I load with the magnitude of the rated current value Ir of the generator main body 2. It is also possible to determine that the connection of the additional load is possible when the sum of the used current value I working and the load current value I load and the load current value I working is lower than the rated current value Ir (Ir > I load + I).

[0178] Next, as an example, a case where a three-phase load is newly connected to the three-phase output terminal block 51 of the AC generator 1 equipped with the generator main body 2 having a rated output Pr of 45 kVA and a rated current Ir of 118 A at 60 Hz and 220 V for three phases will be described.

[0179] Assuming that for the above AC generator 1, due to a load already being connected, the active power P in use is 20 kW, the apparent power S in use is 25 kVA, and the power factor is 0.8 as shown in Table 2 below, the remaining capacity P of the entire AC generator 1 at this time remain is 16 kW.

[0180]

Table 2

[0181] When determining whether it is possible to newly connect a three-phase load with a power consumption of 7.5 kW and a power factor of 0.4 to the AC generator 1 in this state, the current value calculation unit 78a of the determination means 78 uses the total three-phase current value I of the generator main body 2 at the time of detecting the instantaneous value of the voltage and the instantaneous value of the current working as the current value I U working , I V working , I W working (that is, the effective value of the current I rms-U , I rms-V , I rms-W ) and obtains it as the maximum value of any one of them. I working = MAX〔(I U working ) or (I V working ) or (I W working )〕

[0182] The total remaining current value I remain in the AC generator 1 is the value obtained by subtracting the current value I working from the rated current value Ir of the generator main body 2, that is, I remain = Ir - I working Therefore, in the example of Table 2, the remaining current value I remain is I remain=118[A]-65.6[A]=52.4[A] This is the result.

[0183] On the other hand, the load current value I flowing through the newly connected load can be calculated from the power factor and active power consumption in the load information for the newly connected load. load teeth, I load =Power consumption of the load [kW] / (V·√3·power factor), I load =7.5[kW]·1000 / (220[V]·√3·0.4)=49.2[A] This is the result.

[0184] Therefore, in the above example, the load current value I load The remaining current value I of the entire generator body 2 remain A value lower than [I remain (52.4[A])>I load (49.2[A])) and the current value used I working and load current value I working The sum of the values ​​is lower than the rated current value Ir [Ir(118[A])>Ir working (52.4[A])+I load (49.2[A])) As such, the comparison and determination unit 78d of the determination means 78 determines that it is possible to connect the load that is to be newly connected, and lights up the "OK" lamp of the display means.

[0185] This allows users to accurately determine whether or not it is possible to connect a newly scheduled load. [Explanation of Symbols]

[0186] 1 AC generator 2. Generator body UU Aimaki Line VV phase winding WW phase winding V' Auxiliary winding N neutral point v, w, u, n, v' Output terminals (of the generator body) U2, W2 Intermediate Tap 20U, 20V, 20W, 20V' Main output circuit 30U,30V,30W three-phase output circuit 31 Three-phase circuit breaker 40U, 40V', 40W, 40U2, 40N, 40W2 Single-phase output circuit 41 Single-phase circuit breaker 51 Three-phase output terminal block 52 Single-phase output terminal block 60 Remaining capacity display device 61U, 61V, 61W, 61V', 61N, 61U2, 61W2 Voltage detection means (voltage detector) 62U, 62V, 62W, 62U2, 62V', 62W2 Current detection means (current detector) 70 Control device (controller) 71 Means for calculating available power 72 Apparent power usage calculation method 73 Power Factor Calculation Method 74. Rated Active Power Calculation Method 75 Memory means 76 Remaining capacity calculation means 77. Means for calculating remaining current value 78 Judgment means 78a Current Usage Calculation Unit 78b Remaining current value calculation unit 78c Load current value calculation unit 78d Comparison / judgment section 80,81 Display means (monitor) 100 AC Generator 102 Generator Unit 110 AC output system 120 Output Circuit 130(130U,130V,130W) Three-phase output circuit 140 (140U, 140V, 140W) Single-phase output circuit 151 Three-phase output terminal block 152 Single-phase output terminal block L1~L4 load 3φ three-phase AC output system 1φ Single-phase AC output system 1φ U-V’ ,1φ W-V’ ,1φ U2-N,1φ W2-N Low-voltage single-phase AC output system 1φ U-W High-voltage single-phase AC output system V is the instantaneous value of the voltage. V rms RMS value of voltage I. Instantaneous value of current I rms Effective value of current P: Active power used S Apparent power used PF Power Factor Pr Generator Rated Output Pr active Rated active power P remain Remaining capacity I working Current usage value Ir Generator Unit Rated Current Value I remain Residual current value I load Load current value

Claims

1. In a method for displaying the remaining capacity of an AC generator comprising a generator body, a three-phase output terminal block, a single-phase output terminal block, a three-phase output circuit connecting the generator body and the three-phase output terminal block, and a single-phase output circuit connecting the generator body and the single-phase output terminal block, wherein the three-phase output circuit and the three-phase output terminal block form a three-phase AC output system that outputs three-phase AC to a three-phase load, and the single-phase output circuit and the single-phase output terminal block form a single-phase AC output system that outputs single-phase AC to a single-phase load, A voltage detection process that sequentially detects the instantaneous voltage values ​​of the three-phase AC output system and the single-phase AC output system, A current detection process that sequentially detects the instantaneous values ​​of the current in the three-phase AC output system and the single-phase AC output system, Based on the instantaneous voltage and current values, a process for calculating the active power used, which is the power used by the three-phase AC output system and the single-phase AC output system at the time the instantaneous voltage and current values ​​are detected, is performed. An apparent power usage calculation process that calculates the apparent power usage, which is the power used by the three-phase AC output system and the single-phase AC output system at the time of detection, based on the effective value of the voltage calculated based on the instantaneous value of the voltage and the effective value of the current calculated based on the instantaneous value of the current, A power factor calculation process that calculates the power factor of the generator body at the time of detection based on the ratio of the active power used and the apparent power used, A rated active power calculation process, which involves correcting the generator rated output, which is the rated output of the generator body, using the power factor, to calculate the rated active power of the generator body at the time of detection, and thereby calculating the rated active power of the generator body at the time of detection, A remaining capacity calculation process that calculates the difference between the rated active power and the active power used as the remaining capacity of the AC generator at the time of detection. Includes, A method for displaying the remaining capacity of an AC generator, characterized in that, in the remaining capacity calculation process, the remaining capacity is calculated as the remaining capacity of the three-phase AC output system and the remaining capacity of the single-phase AC output system, respectively.

2. The single-phase AC output system includes a low-voltage single-phase AC output system that provides a single-phase output at a predetermined lower voltage than the three-phase output voltage. The method for displaying remaining capacity in an AC generator according to claim 1, characterized in that the remaining capacity calculation process includes calculating the remaining capacity of the low-voltage single-phase AC output system as the calculation of the remaining capacity of the single-phase AC output system.

3. The single-phase AC output system includes a high-voltage single-phase AC output system that provides a single-phase output at the same voltage as the three-phase output voltage provided by the generator body. The method for displaying remaining capacity in an AC generator according to claim 1 or 2, characterized in that the remaining capacity calculation process includes calculating the remaining capacity of the high-voltage single-phase AC output system as the calculation of the remaining capacity of the single-phase AC output system.

4. A method for displaying remaining capacity in an AC generator according to claim 1 or 2, characterized in that the above-mentioned active power used is calculated by integrating the product of the instantaneous value of the voltage and the instantaneous value of the current and averaging it over one period.

5. A method for displaying remaining capacity in an AC generator according to claim 1 or 2, further comprising a remaining capacity display process for displaying the calculated remaining capacity on a display means.

6. A determination process to determine whether or not it is possible to connect a load that is scheduled to be newly connected, A method for displaying remaining capacity in an AC generator according to claim 1 or 2, further comprising a determination result display process for displaying the determination result performed in the determination process on a display means.

7. The aforementioned determination process further, A current usage calculation process that determines the current usage value of the generator body at the time of detection from the active power usage of the three-phase AC output system and the single-phase AC output system, A residual current value calculation process that calculates the remaining current value of the generator body by subtracting the usage current value from the rated current value of the generator body, A load current value calculation process calculates the load current value, which is the current value that flows through the load when it is connected, based on the active power consumption, which is the power consumption of the load at its active power value, and the power factor of the load to be newly connected. A method for displaying remaining capacity in an AC generator according to claim 6, characterized in that it includes a comparison and determination process, which involves comparing the remaining current value with the load current value and determining that it is possible to connect the load to be newly connected if the load current value is smaller than the remaining current value.

8. A remaining capacity display device for an AC generator comprising a generator body, a three-phase output terminal block, a single-phase output terminal block, a three-phase output circuit connecting the generator body and the three-phase output terminal block, a single-phase output circuit connecting the generator body and the single-phase output terminal block, wherein the three-phase output circuit and the three-phase output terminal block form a three-phase AC output system that outputs three-phase AC to a three-phase load, and the single-phase output circuit and the single-phase output terminal block form a single-phase AC output system that outputs single-phase AC to a single-phase load, Voltage detection means for sequentially detecting the instantaneous voltage values ​​of the three-phase AC output system and the single-phase AC output system, Current detection means for sequentially detecting the instantaneous values ​​of the current in the three-phase AC output system and the single-phase AC output system, A means for calculating the active power used, which is the power used by the three-phase AC output system and the single-phase AC output system at the time the instantaneous values ​​of the voltage and the current are detected, based on the instantaneous values ​​of the voltage and the current, An apparent power usage calculation means calculates the apparent power usage, which is the power used by the three-phase AC output system and the single-phase AC output system at the time of detection, based on the effective value of the voltage calculated based on the instantaneous value of the voltage and the effective value of the current calculated based on the instantaneous value of the current. A power factor calculation means for calculating the power factor of the generator body at the time of detection based on the ratio of the active power used and the apparent power used, A rated active power calculation means calculates the rated output of the generator body at the time of detection as the rated active power by correcting the generator rated output of the generator body stored in the storage means using the power factor, A remaining capacity calculation means calculates the difference between the rated active power and the active power used as the remaining capacity of the AC generator at the time of detection. Equipped with, A remaining capacity display device for an AC generator, characterized in that the remaining capacity calculation means calculates the remaining capacity of the three-phase AC output system and the remaining capacity of the single-phase AC output system as the remaining capacity.

9. The single-phase AC output system includes a low-voltage single-phase AC output system that provides a single-phase output at a predetermined lower voltage than the three-phase output voltage. The remaining capacity display device for an AC generator according to claim 8, characterized in that the remaining capacity calculation means includes calculating the remaining capacity of the low-voltage single-phase AC output system in calculating the remaining capacity of the single-phase AC output system.

10. The single-phase AC output system includes a high-voltage single-phase AC output system that provides a single-phase output at the same voltage as the three-phase output voltage. The remaining capacity display device for an AC generator according to claim 8 or 9, characterized in that the remaining capacity calculation means includes calculating the remaining capacity of the high-voltage single-phase AC output system in calculating the remaining capacity of the single-phase AC output system.

11. The remaining capacity display device for an AC generator according to claim 8 or 9, characterized in that the means for calculating the active power used calculates the active power used by integrating the product of the instantaneous value of the voltage and the instantaneous value of the current and averaging it over one period.

12. A remaining capacity display device for an AC generator according to claim 8 or 9, further comprising a display means for displaying the calculated remaining capacity.

13. A determination means for determining whether or not it is possible to connect a load that is scheduled to be newly connected, The remaining capacity display device for an AC generator according to claim 8 or 9, further comprising a display means for displaying the determination result performed by the determination means.

14. The determination means, A current usage value calculation unit that determines the current usage value of the generator body at the time of detection from the active power usage of the three-phase AC output system and the single-phase AC output system, A residual current value calculation unit calculates the remaining current value of the generator body by subtracting the usage current value from the rated current value of the generator body stored in the storage means, A load current value calculation unit calculates the load current value, which is the current value that flows through the load when it is connected, based on the active power consumption, which is the power consumption of the load to be newly connected, and the power factor, The remaining capacity display device for an AC generator according to claim 13, further comprising a comparison and determination unit that compares the remaining current value with the load current value and determines that it is possible to connect the load to be newly connected when the load current value is smaller than the remaining current value.

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