KR200260814Y1 - a diagnosis detection systemfor power condenser - Google Patents

Abstract

The present invention relates to a capacitor bank deterioration diagnosing device for a power equipment, comprising: a transformer bank, a current transformer, and a capacitor bank circuit including a capacitor, a reactor, a resistor, and a resistor, wherein the voltage is deformed from the voltage modified from the transformer. A voltage information detector for detecting information, a current information detector for detecting current information from the current flown from the current transformer, an offset and a phase of the voltage information detected by the voltage information detector and the current information detected by the current information detector. An offset and phase correction to be corrected, an unbalanced current detector for detecting an unbalanced current at the front end of the resistor in the capacitor bank, voltage and current information corrected by the offset and phase correction, and an unbalanced current detector Unbalance current information according to a certain resolution And a discharge state during partial discharge of the capacitor bank from the digital current information, the analog / digital converting unit converting the digital unbalanced current information, the voltage information detected by the voltage information detecting unit and the current information detected by the current information detecting unit. A discharge incidence detecting unit for detecting a discharge state detection unit for comparing the voltage information detected by the voltage information detecting unit and the current information detected by the current information detecting unit with a reference voltage and a reference current, and detecting a surge intrusion signal according to the comparison result And deterioration of the capacitor bank according to the digital voltage information, the digital current information and the digital unbalanced current converted from the analog / digital converter, the discharge state information detected by the discharge state detection unit, and the surge intrusion information detected by the surge intrusion detection unit. Digital scene that outputs control signal corresponding to state after determining A processing unit, an alarm unit for alarming the deterioration state of the capacitor bank according to the control signal of the digital signal processing unit, and a communication unit for notifying a user of the occurrence state of deterioration of the capacitor bank according to the control signal of the digital signal processing unit. The insulation deterioration state of the device is diagnosed in advance through the factors and frequency of deterioration due to surge and overvoltage occurring during the opening and closing of the condenser bank installed in the 154㎸ power system. By providing information such as working capacity and three-phase unbalanced current to the user, it is effective to minimize the efficiency of operation and the ripple situation due to failure.

Description

Capacitor bank deterioration diagnostic apparatus of power equipment {a diagnosis detection system for power condenser}

The present invention relates to a capacitor bank of a power equipment. In particular, the capacitor bank deterioration of a power equipment for diagnosing the insulation deterioration state of a capacitor bank, which is a type of voltage regulator for supplying high quality power by minimizing voltage fluctuations in a power system. It relates to a diagnostic device.

Hereinafter, a capacitor bank circuit of a power equipment according to the prior art will be described with reference to the accompanying drawings.

1 is a schematic diagram of an operating state of a condenser bank circuit of a power equipment according to the prior art, including transformers 1 to 3, breakers 4 to 6, current transformers 7 to 9, and reactors 10 to 12; And the capacitors 13 to 15 and the resistor 16, and the reactors 10 to 12, the capacitors 13 to 15, and the resistor 16 constitute a capacitor bank.

Referring to the accompanying drawings, the operation of the capacitor bank circuit of the power equipment according to the prior art configured as described in detail as follows.

Due to the characteristics of the electric circuit, a circuit in which a capacitor and a reactor are connected in series has a resonance frequency in which resonance occurs. If the resonant frequency is equal to the frequency applied from the outside, a large flow of energy may exist and the capacitor may be destroyed. Therefore, the 3 harmonics (180 Hz) and 5 harmonics (300 Hz) that may exist in the power system may be avoided. It is common to design the resonant frequency of the capacitor bank.

As shown in FIG. 1, the capacitor bank is connected to the reactors 10 to 12 and the capacitors 13 to 15, respectively, in series, and serves as a resistor 16 for reducing an abnormal voltage and minimizing the risk of charging current. It is composed.

The capacity of the capacitor bank means a value obtained by subtracting the reactor capacity from the capacitor capacity operating at the rated voltage. At this time, the reactors 10 to 12 and the condenser 13 to 15 are determined by the rated voltage, rated current, and rated capacity. In this case, the rating is determined by the steady state analysis.

However, in the actual operating situation, it is a real phenomenon that the rated voltage, the voltage higher than the rated current flows instantaneously by the resonance frequency, the breaking operation and the closing operation of the breakers 4-6. Such instantaneous overcurrent and overvoltage act as a cause of deterioration of the reactors 10 to 12 and the capacitors 13 to 15 forming the capacitor bank.

Therefore, a failure occurs due to the insulation deterioration state of the device due to surge and overvoltage that occurs when opening and closing a condenser bank installed in the 154 kHz power system, and it causes a great effect on the voltage quality. do.

In addition, the information transmitted to the user to operate the capacitor bank is the current information by the current transformers (7 to 9) and the voltage information by the transformers (1 to 3) are all provided as a scale or a number, so the transient over-voltage and Overcurrent information is not provided to the user. Further, information such as the capacity of the capacitor bank acting during operation is not provided to the user.

Therefore, the present invention has been devised to solve the above problems, and the isolation of the device through the factors and frequency of deterioration due to surge and overvoltage generated when opening and closing the capacitor bank (condenser bank) installed in the 154 kHz power system Diagnose the degradation condition in advance and provide the user with information such as the working capacity of capacitor bank and three-phase unbalanced current during steady state operation to minimize the ripple situation due to operation efficiency and failure, It is an object of the present invention to provide a capacitor bank degradation diagnosis device.

1 is a schematic diagram of an electric circuit of an operating state of a capacitor bank of a power installation according to the prior art;

2 is a view showing an embodiment of a capacitor bank deterioration diagnostic apparatus of a power equipment according to the present invention

FIG. 3 is a diagram illustrating a detailed configuration of the voltage information detector of FIG. 2.

4 is a diagram illustrating a detailed configuration of the current information detection unit of FIG.

5 is a diagram illustrating a detailed configuration of the digital signal processing unit of FIG.

6 is a schematic diagram of the voltage and current waveform of FIG.

7 is a conceptual diagram of waveforms detected by a discharge state detection unit during partial discharge of the capacitor bank of FIG. 2.

Explanation of symbols for main parts of the drawings

1 ~ 3: Transformer 4 ~ 6: Breaker

7 ~ 9 Current transformer 10 ~ 12: Reactor

13 ~ 15: Capacitor 16: Resistance

110: voltage information detector 111: voltage divider

112: voltage amplifier 120: current information detector

121: current transformer 122: current amplifier

130: offset and phase correction

140: unbalanced current detector 150: analog / digital conversion unit

160: discharge state detection unit 170: surge intrusion detection unit

180: digital signal processing unit 181: storage unit

182: phase detection unit 183: surge intrusion counting unit

184: control unit 190: alarm unit

200: communication unit

A feature of the condenser bank deterioration diagnosing device of a power plant according to the present invention for achieving the above object is a condenser bank circuit of a power plant having a transformer, a current transformer, and a condenser bank composed of a capacitor, a reactor, and a resistor. A voltage information detector for detecting voltage information from the voltage deformed from the transformer, a current information detector for detecting current information from a current flown from the current transformer, a voltage information detected by the voltage information detector, and a current information detector An offset and phase compensator for correcting the offset and phase of the detected current information, an unbalance current detector for detecting an unbalance current at the front end of the resistor in the capacitor bank, and voltage information and current information corrected at the offset and phase compensator. And the unbalanced current information detected by the unbalanced current detector at a constant resolution. D) the capacitor bank from the digital voltage information and the digital current information corresponding thereto, the analog / digital converter converting the digital unbalanced current information, the voltage information detected by the voltage information detector and the current information detected by the current information detector. The discharge state detection unit for detecting the discharge state during the partial discharge of the voltage, the voltage information detected by the voltage information detection unit and the current information detected by the current information detection unit are compared with the reference voltage and the reference current, respectively, and then surge intrusion according to the comparison result. A surge intrusion detection unit for detecting a signal, digital voltage information, digital current information and digital unbalanced current converted from the analog / digital conversion unit, discharge state information detected in the discharge state detection unit, and surge intrusion detection detected in the surge intrusion detection unit Determine the deterioration state of the capacitor bank according to the information and then correspond The digital signal processor outputs a control signal, an alarm unit for alarming the deterioration state of the capacitor bank according to the control signal of the digital signal processor, and a generation state of the deterioration of the capacitor bank according to the control signal of the digital signal processor. It is configured to include a communication unit for notifying.

The voltage information detector includes a voltage divider for dividing the voltage deformed from the transformer at a ratio of 100: 1, and a voltage amplifier for amplifying the voltage distributed by the voltage divider to detect voltage information. It is supposed to be.

The current information detector is a current transformer for detecting the current information by amplifying the current flowing in the current transformer in the current transformer in the current transformer according to the winding ratio of primary winding: secondary winding = 100: 1. It is another feature that the configuration including the wealth.

The unbalanced current detector is further characterized in that it detects an unbalanced current when a three-phase unbalance generation or surge occurs in the outside of the resistor in the capacitor bank.

The discharge state detector further detects the discharge state by simultaneously decreasing and increasing the voltage information and the current information respectively detected by the voltage information detector and the current information detector at the partial discharge of the capacitor bank. have.

The surge intrusion detection unit compares the voltage information detected by the voltage information detection unit and the current information detected by the current information detection unit with a reference voltage and a reference current, respectively, when an abnormal voltage and an overcurrent exceeding a reference value occur in the form of a pulse. It is another feature to generate a surge intrusion signal.

The constant resolution of the analog / digital converter is another feature of 16 bits.

The digital signal processor may be configured to convert digital voltage information, current information, and unbalanced current information converted by the analog / digital converter into a constant resolution, a discharge state signal detected by the discharge state detector, and a surge intrusion signal detected by the surge intrusion detector. A storage unit for storing in a predetermined area, a phase detector for detecting a phase from the voltage information and current information stored in the storage unit, and a surge intrusion count unit for counting the number of surge intrusions and the intensity from the surge intrusion signal stored in the storage unit. And after synchronizing the digital voltage information and the digital current information stored in the storage unit with the phase detected by the phase detection unit, the capacity and element values of the reactor and the capacitor are calculated by referring to the design values of the reactor and the capacitor. Waveforms other than the fundamental wave, unbalanced current information stored in the storage unit and the surge guide That is configured to include a surge intrusion recovered and then analyzed by determining the deterioration state of the capacitor bank the intensity control section for outputting a control signal corresponding to the count in the counting unit is another feature.

The phase detecting unit detects a phase by comparing only a fundamental wave component of a current according to current information stored in the storage unit with a voltage according to voltage information.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of the embodiments with reference to the accompanying drawings.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the capacitor bank deterioration diagnostic apparatus of the power equipment according to the present invention will be described.

2 is a view showing an embodiment of a capacitor bank deterioration diagnostic apparatus of a power equipment according to the present invention, the voltage information detection unit 110, the current information detection unit 120, the offset (offset) and phase correction unit 130 Unbalance current detection unit 140, analog / digital conversion unit 150, discharge state detection unit 160, surge intrusion detection unit 170, digital signal processing unit 180 and alarm unit 190, communication unit And 200.

The voltage information detection unit 110 detects the voltage information of each of the transformers 1 to 3 from the voltage modified from each of the transformers 1 to 3 shown in FIG. 1, and the current information detection unit 120 Current information of each of the current transformers 7 to 9 is detected from currents flowed from each of the current transformers 7 to 9 shown in FIG.

The offset and phase compensator 130 is the voltage information of each of the transformers (1 ~ 3) detected by the voltage information detector 110 and the current of each of the current transformers (7 ~ 9) detected by the current information detector 110 The offset and phase of the information are corrected.

The unbalanced current detector 140 detects a three-phase unbalanced current at the front end of the resistor 16 shown in FIG.

The analog / digital converter 150 converts the voltage information and the current information corrected by the offset and phase correction unit 130 and the three-phase unbalanced current information detected by the unbalanced current detector 140 to 16 bits of resolution. Accordingly, the digital voltage information, the digital current information, and the digital unbalanced current information are converted into corresponding ones.

The discharge state detection unit 160 includes voltage information of each of the transformers 1 to 3 detected by the voltage information detection unit 110 and current information of each of the current transformers 7 to 9 detected by the current information detection unit 120. The discharge state is detected at the partial discharge of the capacitor bank. The discharge state is the voltage information and the current information detected by the voltage information detector 110 and the current information detector 120 at the time of partial discharge of the capacitor bank. It is detected by decreasing and increasing each instantaneously.

The surge intrusion detecting unit 170 compares the voltage information and the current information detected by the voltage information detecting unit 110 and the current information detecting unit 120 with a reference voltage and a reference current, respectively, so that an abnormal voltage and an overcurrent exceeding a reference value are exceeded. When generated, a surge intrusion signal in the form of a pulse is generated.

The digital signal processing unit 180 is digital voltage information, digital current information and digital unbalanced current converted from the analog / digital conversion unit 150 and the discharge state information detected by the discharge state detection unit 160 and the surge intrusion detection unit. The deterioration state of the capacitor bank is determined according to the surge intrusion information detected at 170, and then a corresponding control signal is output.

The alarm unit 190 alerts the deterioration state of the capacitor bank according to the control signal of the digital signal processing unit 180.

The communication unit 200 notifies the user of the occurrence of deterioration of the capacitor bank according to the control signal of the digital signal processing unit 180.

3 is a diagram illustrating a detailed configuration of the voltage information detector of FIG. 2, wherein the voltage information detector 110 includes a voltage divider 111 and a voltage amplifier 112.

The voltage divider 111 distributes the voltages modified from the transformers 1 to 3 at a ratio of 100: 1.

The voltage amplifier 112 detects respective voltage information by amplifying the voltages respectively distributed by the voltage divider 111.

4 is a diagram illustrating a detailed configuration of the current information detector of FIG. 2, wherein the current information detector 120 includes a current transformer 121 and a current amplifier 122.

The current transformer 121 currents the currents flowed by the current transformers 7 to 9 according to a winding ratio of primary winding: secondary winding = 100: 1.

The current amplifier 122 detects each current information by amplifying the currents respectively flowed by the current transformer 121.

5 is a diagram illustrating a detailed configuration of the digital signal processor of FIG. 2, wherein the digital signal processor 180 includes a storage unit 181, a phase detector 182, a surge intrusion count unit 183, and a controller ( 184).

The storage unit 181 may include digital voltage information, current information, and unbalanced current information converted by the analog / digital conversion unit 150 with a resolution of 16 bits, a discharge state signal detected by the discharge state detection unit 160, And the surge intrusion signal detected by the surge intrusion detecting unit 170 in a predetermined area.

The phase detector 182 detects a phase from voltage information and current information stored in the storage unit 181.

The surge intrusion counting unit 183 counts the number and the number of surge intrusions stored in the storage unit 181.

The controller 184 synchronizes the digital voltage information and the digital current information stored in the storage unit 181 with the phase detected by the phase detection unit 182, and then, respectively, the reactors 10 to 12 and the capacitors 13 to 15, respectively. After calculating the capacitance and the element value of each of the reactors 10 to 12 and the capacitors 13 to 15 with reference to the design value of the waveform, the waveform excluding the fundamental wave among the current components and the unbalanced current information stored in the storage unit 181. And analyzing the number of surge intrusions and the strengths counted by the surge intrusion counting unit 183 to determine the deterioration state of the capacitor bank and output a control signal corresponding thereto.

6 is a schematic diagram of the voltage and current waveforms of FIG. 2, and FIG. 7 is a conceptual diagram of waveforms detected by a discharge state detector during partial discharge of the capacitor bank of FIG. 2.

The operation of the capacitor bank deterioration diagnostic apparatus of the power equipment according to the present invention configured as described above will be described in detail with reference to FIGS. 1 to 7.

Description of components and operations shown in FIG. 1 are the same as described above, and thus descriptions thereof are omitted, and the transformers 1 to 3, the breakers 4 to 6, the current transformers 7 to 9, and the reactors are omitted. 10 to 12 and the capacitors 13 to 15 perform the same operation only with the input phases different from A, B, and C, so that the transformer 1 and the circuit breaker 4 are based on the phase A. Only the capacitor bank composed of the current transformer 7, the reactor 10, and the capacitor 13 will be described, and the transformers 2, 3, the breakers 5, 6, The description of the operation state of the capacitor bank composed of the current transformers 8 and 9, the reactors 11 and 12 and the capacitors 14 and 15 will be omitted.

First, the voltage information detector 110 detects voltage information from the voltage modified from the transformer 1 shown in FIG. That is, as shown in FIG. 3, the voltage divider 111 in the voltage information detector 110 distributes the voltage modified from the transformer 1 at a predetermined ratio of 100: 1. Then, the voltage amplifier 112 detects the voltage information by amplifying the voltage distributed by the voltage divider 111.

The current information detection unit 120 detects current information from the current flowed from the current transformer 7 shown in FIG. That is, as shown in FIG. 4, the current transformer 121 in the current information detector 120 causes the current flown in the current transformer 7 to flow according to a turns ratio of primary winding: secondary winding = 100: 1. do. Then, the current amplifier 122 detects current information by amplifying the current flowing in the current transformer 121.

Accordingly, the offset and phase correction unit 130 corrects the offset and phase of the voltage information detected by the voltage information detector 110 and the current information detected by the current information detector 110.

On the other hand, the unbalanced current detector 140 detects the three-phase unbalanced current at the front end of the resistor 16 shown in FIG. That is, in the steady state, the unbalanced current detector 140 equilibrates the three phases A, B, and C in front of the resistor 16 shown in FIG. 1, so that the sum of the vectors of the three phase voltages is zero. It does not operate because it is zero, but it detects this because unbalance current flows when 3 phase unbalance occurs or surge is invaded from outside.

Then, the analog / digital converter 150 adjusts the voltage information and the current information corrected by the offset and phase correction unit 130 and the unbalanced current information detected by the unbalanced current detector 140 according to the resolution of 16 bits. It converts the corresponding digital voltage information, digital current information and digital unbalanced current information.

In addition, the discharge state detector 160 detects a discharge state during partial discharge of the capacitor bank from the voltage information detected by the voltage information detector 110 and the current information detected by the current information detector 120. As shown in FIG. 6, the partial discharge state has waveforms of voltage and current according to voltage information and current information detected by the voltage information detector 110 and the current information detector 120 during partial discharge of the capacitor bank. As shown in FIG. 7, it is detected that each simultaneously decreases and increases at the same time.

In addition, the surge intrusion detecting unit 170 compares the voltage information and the current information detected by the voltage information detecting unit 110 and the current information detecting unit 120 with a reference voltage and a reference current, respectively, and an abnormal voltage and an overcurrent exceeding a reference value. When is generated, the surge intrusion signal in the form of a pulse is detected.

Accordingly, the digital signal processing unit 180 converts the digital voltage information, the digital current information, the digital unbalanced current, and the discharge state information detected by the discharge state detection unit 160 and the surge from the analog / digital conversion unit 150. After determining the deterioration state of the capacitor bank according to the surge intrusion information detected by the intrusion detection unit 170, and outputs a control signal corresponding thereto.

That is, as shown in FIG. 5, the storage unit 181 in the digital signal processing unit 180 converts the digital voltage information, current information, and unbalanced current information converted into 16-bit resolution by the analog / digital converter 150. The discharge state signal detected by the discharge state detection unit 160 and the surge intrusion signal detected by the surge intrusion detection unit 170 are stored in a predetermined region. Here, the surge intrusion signal includes the number of surge intrusions, the intensity and the date information. In addition, the phase detector 182 detects a phase from voltage information and current information stored in the storage unit 181. That is, the phase detector 182 detects only the fundamental wave component of the current according to the current information stored in the storage unit 181 and compares the phase with the voltage according to the voltage information. In addition, the surge intrusion counting unit 183 counts the number of surge intrusions and the strength stored in the storage unit 181. Then, the controller 184 synchronizes the digital voltage information and the digital current information stored in the storage unit 181 with the phase detected by the phase detector 182 and then refers to the design values of the reactor 10 and the condenser 13. After calculating the capacitance and element values of the reactor 10 and the condenser 13 by using the waveform except the fundamental wave of the current component, the unbalanced current information stored in the storage unit 181 and the surge intrusion counting unit 183 The deterioration state of the capacitor bank is determined by analyzing the counted surge incidence and strength, and then a corresponding control signal is output.

Subsequently, the alarm unit 190 alerts the deterioration of the capacitor bank according to the control signal of the controller 184 in the digital signal processor 180. In addition, the communication unit 200 notifies the user of deterioration of the capacitor bank according to the control signal of the controller 184 in the digital signal processing unit 180.

As described above, the capacitor bank deterioration diagnosing device of the power equipment according to the present invention is based on the factors and frequency of deterioration due to surge and overvoltage occurring when the condenser bank is installed in the 154 kW power system. By diagnosing the insulation degradation condition in advance and providing the user with information such as the working capacity of capacitor bank and three-phase unbalanced current during steady state operation, it is possible to minimize the ripple effect due to the efficiency of operation and failure.

From the above description, those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be determined by the scope of utility model registration claims and their equivalents.

Claims (11)

In a capacitor bank circuit of a power plant having a transformer, a current transformer, and a capacitor bank composed of a capacitor, a reactor, and a resistor, A voltage information detector for detecting voltage information from the voltage deformed from the transformer; A current information detector for detecting current information from the current flown from the current transformer; An offset and phase correction unit for correcting the offset and phase of the voltage information detected by the voltage information detector and the current information detected by the current information detector; An unbalanced current detector for detecting an unbalanced current at a front end of the resistor in the capacitor bank; Converting the voltage information and the current information corrected by the offset and phase correction unit and the unbalanced current information detected by the unbalanced current detector into corresponding digital voltage information and digital current information and digital unbalanced current information according to a predetermined resolution. An analog / digital converter; A discharge state detector for detecting a discharge state during partial discharge of the capacitor bank from the voltage information detected by the voltage information detector and the current information detected by the current information detector; A surge intrusion detector which compares the voltage information detected by the voltage information detector and the current information detected by the current information detector with a reference voltage and a reference current, respectively and detects a surge intrusion signal according to the comparison result; The deterioration state of the capacitor bank is determined according to the digital voltage information, the digital current information and the digital unbalanced current converted from the analog / digital converter, the discharge state information detected by the discharge state detection unit, and the surge intrusion information detected by the surge intrusion detection unit. A digital signal processor for determining and outputting a control signal corresponding thereto; An alarm unit for alarming the deterioration state of the capacitor bank according to the control signal of the digital signal processor; And a communication unit for notifying a user of an occurrence of deterioration of the capacitor bank in accordance with a control signal of the digital signal processing unit. The method of claim 1, The voltage information detection unit A voltage distribution unit for distributing the voltage modified from the transformer at a predetermined ratio; And a voltage amplifier configured to amplify the voltage distributed by the voltage divider to detect voltage information. The method of claim 2, The predetermined ratio is 100: 1 capacitor bank degradation diagnostic apparatus of the power equipment. The method of claim 1, The current information detection unit A current transformer for converting the current flowing in the current transformer according to a predetermined turns ratio; And a current amplifier configured to amplify the current flowd by the current transformer to detect current information. The method of claim 4, wherein The constant winding ratio is a primary winding: secondary winding = 100: 1 capacitor bank degradation diagnostic apparatus of the power equipment. The method of claim 1, The unbalanced current detector And an unbalanced current is detected when three-phase unbalance occurs or surges invade from the front end of the resistor in the capacitor bank. The method of claim 1, And a constant resolution of the analog / digital converter is 16 bits. The method of claim 1, The discharge state detection unit Degradation diagnosis of a capacitor bank of a power facility, characterized in that the voltage information detection unit and the current information detection unit at the time of partial discharge of the capacitor bank detect the discharge state by simultaneously decreasing and increasing the voltage information and the current information, respectively. Device. The method of claim 1, The surge intrusion detection unit When the voltage information detected by the voltage information detector and the current information detected by the current information detector are compared with a reference voltage and a reference current, respectively, an abnormal voltage and an overcurrent exceeding a reference value generate a surge intrusion signal in the form of a pulse. Capacitor bank deterioration diagnostic apparatus of the power equipment characterized in that. The method of claim 1, The digital signal processing unit The digital voltage information, current information, and unbalanced current information converted by the analog / digital converter with 16 bits of resolution, the discharge state signal detected by the discharge state detection unit, and the surge intrusion signal detected by the surge intrusion detection unit are fixed. A storage unit for storing in the area; A phase detector for detecting a phase from the voltage information and the current information stored in the storage; A surge intrusion counting unit for counting the number of surge intrusions and the strength of the surge intrusion signals stored in the storage unit; After synchronizing the digital voltage information and the digital current information stored in the storage unit with the phase detected by the phase detection unit, the capacity and element values of the reactor and the capacitor are calculated by referring to the design values of the reactor and the capacitor, and then the fundamental wave of the current component. And a control unit which analyzes the waveform and the unbalanced current information stored in the storage unit, the number of surge intrusions and the intensity counted by the surge intrusion count unit, and determines the deterioration state of the capacitor bank and outputs a control signal corresponding thereto. Capacitor bank deterioration diagnostic apparatus for power equipment, characterized in that configured to. The method of claim 1, The phase detection unit And detecting only a fundamental wave component of the current according to the current information stored in the storage unit and comparing the voltage with the voltage according to the voltage information to detect a phase.