KR101267513B1 - Method for controling ups parallel operation using wireless communication - Google Patents

Method for controling ups parallel operation using wireless communication Download PDF

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KR101267513B1
KR101267513B1 KR1020120003377A KR20120003377A KR101267513B1 KR 101267513 B1 KR101267513 B1 KR 101267513B1 KR 1020120003377 A KR1020120003377 A KR 1020120003377A KR 20120003377 A KR20120003377 A KR 20120003377A KR 101267513 B1 KR101267513 B1 KR 101267513B1
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power
output voltage
inverter
inverters
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Korean (ko)
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홍순찬
이윤하
지준근
임승범
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주식회사 이온
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • H02J9/061—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for DC powered loads
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02B90/20—Smart grids as enabling technology in buildings sector
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
    • Y04S20/12—Energy storage units, uninterruptible power supply [UPS] systems or standby or emergency generators, e.g. in the last power distribution stages

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
  • Inverter Devices (AREA)

Abstract

PURPOSE: A UPS parallel operation control method using a wireless communication is provided to reduce a circulating current by applying a frequency droop control of a reactive power-output voltage. CONSTITUTION: An average voltage amplitude and active power are produced if two inverters reach a power sharing balance state(S10). An average angular frequency and reactive power are produced if two inverters reach the power sharing balance state(S20). A voltage and a current are measured in two inverters through a droop control block diagram(S30). A parallel operation is controlled according to a droop property by calculating a command value of a peak and an angular frequency of an output voltage and calculating average reactive power and average active power in two inverters(S40). [Reference numerals] (AA) Start; (BB) End; (S10) Produce an average voltage amplitude and active power if two inverters reach a power sharing balance state; (S20) Produce an average angular frequency and reactive power if two inverters reach the power sharing balance state; (S30) Measure a voltage and a current in two inverters through a drop control block diagram; (S40) Control a parallel operation according to a droop property by calculating a command value of a peak and an angular frequency of an output voltage and calculating average reactive power and average active power in two inverters

Description

무선통신을 이용한 UPS 병렬 운전 제어 방법{METHOD FOR CONTROLING UPS PARALLEL OPERATION USING WIRELESS COMMUNICATION}TECHNICAL FIELD [0001] The present invention relates to a UPS parallel operation control method using wireless communication,

본 발명은 무선통신을 이용한 UPS 병렬 운전 제어 방법에 관한 것으로 더욱 상세하게는, UPS의 병렬 운전을 위해 통신선 없이 출력 임피던스의 지배요소를 저항으로 고려하여 유도한 P-E, Q-

Figure 112012002776391-pat00001
수하제어를 제공하는 기술에 관한 것이다.The present invention relates to a UPS parallel operation control method using wireless communication, and more particularly, to a UPS parallel operation control method using wireless communication, and more particularly,
Figure 112012002776391-pat00001
To a technique for providing underwater control.

상용전원의 정전 및 전압 변동에 민감한 산업용 첨단 장비, 의료기기, 컴퓨터, 금융, 사무용기기 등 고도의 디지털 정보 처리기기의 사용이 증가하면서 무정전전원장치(Uninterruptible Power System; UPS)의 사용이 증가하고 있다. 특히, 부하가 계속 늘어남에 따라 UPS의 병렬운전이 필요하게 되었고 이에 더해 UPS로 구성된 안전전력망(Secure Power Network ; SPN)의 고장 시에도 부하에 대해 지속적인 전원 공급과 손쉬운 UPS 증설을 위해 리던던시(Redunduncy) 개념이 주로 이용되고 있다.The use of uninterruptible power systems (UPS) is increasing as the use of advanced digital information processing equipment such as industrial advanced equipment, medical equipment, computers, finance, and office equipment, sensitive to power failure and voltage fluctuations of commercial power sources . In particular, as the load continues to increase, the parallel operation of the UPS becomes necessary. In addition, even when the UPS is configured with a secure power network (SPN), the redundant power is supplied to the load, Concept is mainly used.

병렬운전을 하면 고장확률의 기준이 되는 MTBF(Mean Time Between Failures)를 증가시키고 고장이 발생한 UPS의 교체 및 유지보수를 위한 MTTR(Mean Time To Repair)를 감소시켜 비상전원의 제 기능을 수행하게 하는 책무 신뢰성(Mission Reliability)을 높여서 보다 안정된 전원사용이 가능하다. 하지만, UPS 인버터(Inverter) 시스템의 병렬 운전은 여러 가지 문제점이 있다.Parallel operation increases Mean Time Between Failures (MTBF), which is a criterion for failure probability, and reduces the Mean Time To Repair (MTTR) for replacing and maintaining the failed UPS. Mission Reliability is increased, so it is possible to use more stable power. However, parallel operation of a UPS inverter system has several problems.

이론적으로는 모든 UPS 인버터 출력전압의 크기(Amplitude), 주파수(Frequency), 위상(Phase)이 같고 출력전류(Output Current)도 같다면 각개 UPS 인버터의 이상적인 부하 분담(Load Sharing)이 가능하다. 그러나 현실적으로 각개 인버터의 물리적인 차이, 라인 임피던스(Line Impedance)의 차이 같은 문제들로 인해서 부하분담은 정확히 되지 않는다. 이에 더해 부하 분담 불평형은 순환전류(Circulating Current)에 의한 UPS 인버터의 고장이나 과부하 상태를 유발시킬 수 있다.Theoretically, ideal load sharing of individual UPS inverters is possible if all UPS inverter output voltages have the same amplitude, frequency and phase and the same output current. In reality, however, load sharing is not precisely due to problems such as physical differences in the individual inverters and differences in line impedances. In addition, the load imbalance imbalance can cause the UPS inverter to malfunction or overload due to circulating current.

일반적으로, 병렬 무정전전원장치(Uninterruptible Power System: UPS) 인버터 시스템의 제어방법들은 크게 두 가지로 분류된다.Generally, the control methods of the parallel uninterruptible power system (UPS) inverter system are classified into two types.

첫째, 통신선(Communication Line)이 필요한 제어방법으로서 중앙 제어(Centralized Control), 주종(Master-Slave, 이하 MS라고 칭함) 제어, 평균 전류 분담(Average Current Sharing, 이하 ACS라고 칭함) 제어, 환형 연결 제어(Circular Chain Control, 이하 3C라고 칭함)가 있다. 이 방법들은 우수한 인버터의 출력전압 제어와 전류분담(Current Sharing)이 가능하나 통신선이 필요하기 때문에 신뢰성과 확장성이 떨어지는 문제점이 있다.First, as a control method requiring a communication line, there are a centralized control, a master-slave (hereinafter referred to as MS) control, an average current sharing (ACS) control, (Circular Chain Control, hereinafter referred to as 3C). These methods have excellent inverter output voltage control and current sharing. However, since they require communication lines, reliability and scalability are poor.

둘째, 통신선이 없는 제어방법(Wireless Control)으로서 수하(Droop) 특성에 기초한 병렬 운전 방법들이 있다. 이 방법들은 각개 UPS 인버터의 출력전압 주파수와 크기를 수하 특성으로 제어하여 유효전력 및 무효전력을 제어하는 방법이다. 수하 제어방법은 통신선 없이 각개 인버터의 출력전압 및 출력전류 정보만을 이용하기 때문에 통신선을 사용하는 제어방법들이 가지는 단점인 감지잡음, 상호간섭 문제가 없어져 더 높은 신뢰성과 확장성을 지니게 된다.Second, there are parallel operation methods based on droop characteristics as a wireless control without a communication line. These methods are a method of controlling active power and reactive power by controlling the output voltage frequency and magnitude of each UPS inverter under the subordinate characteristics. Since the underwater control method uses only the output voltage and output current information of each inverter without communication line, there is no problem of detection noise and mutual interference which are the disadvantages of the control methods using the communication line, so that they have higher reliability and expandability.

기존의 수하 제어는 동기발전기의 유/무효전력(Active/Reactive Power) 제어 알고리즘을 적용한 것으로 UPS 인버터의 출력 임피던스의 지배 성분을 인덕턴스로 가정하고 저항성분을 0으로 하여 유도함으로써

Figure 112012002776391-pat00002
(유효전력-출력전압의 주파수) 수하 및
Figure 112012002776391-pat00003
(무효전력-출력전압의 피크값)수하 제어를 수행하여 UPS 인버터의 출력 유/무효전력을 제어한다.The existing underload control is based on the Active / Reactive Power control algorithm of the synchronous generator. It is assumed that the dominant component of the output impedance of the UPS inverter is assumed as inductance and the resistance component is set to 0
Figure 112012002776391-pat00002
(Active power - frequency of output voltage) and
Figure 112012002776391-pat00003
(Reactive power - peak value of output voltage) to control the output oil / reactive power of the UPS inverter.

무정전전원장치와 관련해서는 대한민국 공개특허 제2009-0047794호(무정전전원장치의 상태알림장치 및 그 방법) 외에 다수의 선행문헌이 공개된바 있다. 도 1은 종래의 수하 제어의 개념도로 UPS 인버터 사이의 통신선이나 별도의 중앙 제어기를 필요로 하지 않고, 각개 UPS 인버터의 출력전류(또는 필터 인덕터전류)와 출력전압을 측정하여 평균 유/무효전력을 계산한 다음

Figure 112013011810324-pat00004
,
Figure 112013011810324-pat00005
수하를 적용하여 출력 전압 지령의 각주파수
Figure 112013011810324-pat00006
와 출력 전압 지령의 피크 크기
Figure 112013011810324-pat00007
값을 얻어서 생성한 출력 전압 지령(Reference of the Output Voltage)을 인버터 전압 제어 루프로 보내는 방식이다.In connection with the uninterruptible power supply, Korean Patent Laid-Open No. 2009-0047794 (status notification device and method of uninterruptible power supply) and a number of prior documents have been disclosed. FIG. 1 is a conceptual view of a conventional underflow control system. In FIG. 1, the output current (or filter inductor current) and the output voltage of each UPS inverter are measured without using a communication line between the UPS inverters or a separate central controller. After calculating
Figure 112013011810324-pat00004
,
Figure 112013011810324-pat00005
Apply the load voltage to each frequency of the output voltage command
Figure 112013011810324-pat00006
And the peak magnitude of the output voltage command
Figure 112013011810324-pat00007
And the generated output voltage reference is sent to the inverter voltage control loop.

그러나, 이 방식은 기본적으로 대전력계통(Large-Scale Power Systems)의 교류 발전기 출력 전력에 대한 제어 전략을 UPS의 병렬운전에 적용한 것으로 대전력계통에서는 출력 필터의 인덕터가 크고 라인 임피던스의 지배 요소 역시 인덕턴스이기 때문에 문제가 없었으나, UPS 인버터 시스템과 같은 저전압 계통의 출력 임피던스에서는 인덕턴스 성분의 지배가 참이 아닐 수 있어 신뢰성이 저하되는 문제점이 있다.However, this method basically applies the control strategy of alternator output power of large-scale power systems to parallel operation of UPS. In large power system, the output filter has a large inductor and the dominant factor of line impedance is There is no problem because it is the inductance, but in the output impedance of the low voltage system such as the UPS inverter system, the dominance of the inductance component may not be true and the reliability is deteriorated.

또한, 출력 임피던스는 라인 임피던스뿐만이 아니라 인버터의 LC 필터, 제어기의 영향을 받으며, 출력 임피던스에 저항 성분이 있을 경우

Figure 112012002776391-pat00008
,
Figure 112012002776391-pat00009
수하제어 방식은 유효전력과 무효전력사이에 간섭을 발생시켜 정확한 부하 분담이 이루어지지 않을 수 있는 단점이 있다.In addition, the output impedance is influenced not only by the line impedance but also by the LC filter and the controller of the inverter. When there is a resistance component in the output impedance
Figure 112012002776391-pat00008
,
Figure 112012002776391-pat00009
The under load control method has a disadvantage in that accurate load sharing may not be achieved due to interference between active power and reactive power.

본 발명은 상기와 같은 문제점을 해결하고자 안출된 것으로, UPS의 비통신선(Wireless) 병렬 운전 방법에 관한 것으로 라인 임피던스의 변동 및 불일치, UPS 인버터들의 물리적인 차이, 및 부하 증가시에도 안정적으로 부하를 분담하면서 출력전압을 유지하도록 제어함에 그 목적이 있다.Disclosure of Invention Technical Problem [8] The present invention has been made to solve the above-mentioned problems, and it relates to a method of parallel operation of a wireless non-communication line of a UPS, which can stably load the UPS even when the line impedance is fluctuated and inconsistent, So that the output voltage can be maintained while sharing the output voltage.

이러한 기술적 과제를 달성하기 위한 무선통신을 이용한 UPS 병렬 운전 제어 방법은, 두개의 인버터 각각이 전력 분담 평형상태에 이르는 경우, 평형 전압 크기 및 유효전력(

Figure 112012002776391-pat00010
)을 도출하는 (a) 단계; 두개의 인버터 각각이 전력 분담 평형상태에 이르는 경우, 평형 각주파수 및 무효전(
Figure 112012002776391-pat00011
)을 도출하는 (b) 단계; 유효전력-출력전압의 피크값(
Figure 112012002776391-pat00012
), 무효전력-출력전압의 주파수(
Figure 112012002776391-pat00013
) 수하제어의 블록다이어그램을 통해 두 개의 인버터 각각에 대한 전압과 전류를 측정하는 (c) 단계; 및 두 개의 인버터 각각에 대한 평균 유효전력 및 평균 무효전력을 계산하고, 출력 전압의 각주파수와 피크 크기의 지령값을 계산하여 유효전력-출력전압의 피크값(
Figure 112012002776391-pat00014
), 무효전력-출력전압의 주파수(
Figure 112012002776391-pat00015
) 수하특성에 따라 병렬운전을 제어하는 (d) 단계;를 포함한다.In order to achieve the above technical object, a UPS parallel operation control method using wireless communication is a method in which when two inverters reach a power sharing equilibrium state, a balanced voltage magnitude and an effective power
Figure 112012002776391-pat00010
(A); When each of the two inverters reaches a power sharing equilibrium state,
Figure 112012002776391-pat00011
(B); Active power - Peak value of output voltage (
Figure 112012002776391-pat00012
), Reactive power - frequency of the output voltage (
Figure 112012002776391-pat00013
(C) measuring the voltage and current for each of the two inverters through a block diagram of the underflow control; And the average reactive power and the average reactive power for each of the two inverters are calculated and a command value of each frequency and peak size of the output voltage is calculated to calculate a peak value of the active power-
Figure 112012002776391-pat00014
), Reactive power - frequency of the output voltage (
Figure 112012002776391-pat00015
(D) controlling the parallel operation according to the load characteristics.

상기와 같은 본 발명에 따르면, UPS 인버터의 출력 임피던스 지배 성분을 저항으로 가정함으로써, 유효전력-출력전압의 피크값(

Figure 112012002776391-pat00016
), 무효전력-출력전압의 주파수(
Figure 112012002776391-pat00017
) 수하제어를 적용하여 부하 증가 시에도 안정적으로 부하를 분담하고 인버터간의 위상차가 유효전력의 분담에 영향을 적게 주므로 순환전류를 줄일 수 있는 효과가 있다.According to the present invention as described above, by assuming that the output impedance dominant component of the UPS inverter is a resistance, the peak value of the active power-output voltage
Figure 112012002776391-pat00016
), Reactive power - frequency of the output voltage (
Figure 112012002776391-pat00017
), The load is shared stably even when the load is increased, and the phase difference between the inverters is less influenced by the sharing of the effective power, thereby reducing the circulating current.

도 1은 종래의 부하망에 연결된 인버터 등가회로를 도시한 도면.
도 2는 본 발명에 따른 무선통신을 이용한 UPS 병렬 운전 제어 방법의 유효전력-전압 수하특성을 도시한 도면.
도 3은 본 발명에 따른 무선통신을 이용한 UPS 병렬 운전 제어 방법의 무효전력-주파수 수하특성을 도시한 도면.
도 4는 본 발명에 따른 무선통신을 이용한 UPS 병렬 운전 제어 방법의 무효전력-주파수 부하 특성을 도시한 도면.
도 5는 본 발명에 따른 무선통신을 이용한 UPS 병렬 운전 제어 방법의

Figure 112012002776391-pat00018
,
Figure 112012002776391-pat00019
수하제어 블록다이어그램을 도신한 도면.
도 6은 본 발명에 따른 무선통신을 이용한 UPS 병렬 운전 제어 방법을 도시한 순서도.
도 7은 본 발명에 따른 무선통신을 이용한 UPS 병렬 운전 제어 방법의 제S10단계 이전 과정을 도시한 순서도.1 shows an inverter equivalent circuit connected to a conventional load network;
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a UPS parallel operation control method using wireless communication.
3 is a diagram illustrating a reactive power-frequency receiving characteristic of a UPS parallel operation control method using wireless communication according to the present invention.
4 is a diagram illustrating a reactive power-frequency load characteristic of a UPS parallel operation control method using wireless communication according to the present invention.
5 is a flowchart illustrating a method of controlling parallel operation of UPS using wireless communication according to the present invention.
Figure 112012002776391-pat00018
,
Figure 112012002776391-pat00019
Drawing on the underflow control block diagram.
6 is a flowchart showing a UPS parallel operation control method using wireless communication according to the present invention.
FIG. 7 is a flowchart illustrating a process before step S10 of a UPS parallel operation control method using wireless communication according to the present invention. FIG.

본 발명의 구체적인 특징 및 이점들은 첨부도면에 의거한 다음의 상세한 설명으로 더욱 명백해질 것이다. 이에 앞서, 본 명세서 및 청구범위에 사용된 용어나 단어는 발명자가 그 자신의 발명을 가장 최선의 방법으로 설명하기 위해 용어의 개념을 적절하게 정의할 수 있다는 원칙에 입각하여 본 발명의 기술적 사상에 부합하는 의미와 개념으로 해석되어야 할 것이다. 또한, 본 발명에 관련된 공지 기능 및 그 구성에 대한 구체적인 설명이 본 발명의 요지를 불필요하게 흐릴 수 있다고 판단되는 경우에는, 그 구체적인 설명을 생략하였음에 유의해야 할 것이다.Specific features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, terms and words used in the present specification and claims are to be interpreted in accordance with the technical idea of the present invention based on the principle that the inventor can properly define the concept of the term in order to explain his invention in the best way. It should be interpreted in terms of meaning and concept. It is to be noted that the detailed description of known functions and constructions related to the present invention is omitted when it is determined that the gist of the present invention may be unnecessarily blurred.

도 1은 부하망에 연결된 인버터의 등가회로를 도시한 도면이다. 도 1에 도시된 바와 같이 부하망으로 전달되는 유효전력 및 무효전력은 아래의 [수학식 1] 및 [수학식 2]와 같이 도출된다.1 is a diagram showing an equivalent circuit of an inverter connected to a load network. As shown in FIG. 1, the active power and the reactive power delivered to the load network are derived as shown in the following equations (1) and (2).

Figure 112012002776391-pat00020
Figure 112012002776391-pat00020

Figure 112012002776391-pat00021
Figure 112012002776391-pat00021

상기 [수학식 1] 및 [수학식 2]에서

Figure 112012002776391-pat00022
는 인버터 출력전압의 부하망 전압의 피크 크기(Peak-amplitude)이고,
Figure 112012002776391-pat00023
는 전력각(Power Angle)이며,
Figure 112012002776391-pat00024
와
Figure 112012002776391-pat00025
는 출력 임피던스의 크기(Magnitude)와 위상각(Phase Angle)이다. 또한, 출력 임피던스를 순수 저항으로 가정하면
Figure 112012002776391-pat00026
, [수학식 3] 및 [수학식 4]와 같다.In equations (1) and (2) above,
Figure 112012002776391-pat00022
Is the peak-amplitude of the load voltage of the inverter output voltage,
Figure 112012002776391-pat00023
Is the power angle,
Figure 112012002776391-pat00024
Wow
Figure 112012002776391-pat00025
Is the magnitude of the output impedance (magnitude) and the phase angle (phase angle). Assuming that the output impedance is a pure resistance
Figure 112012002776391-pat00026
, [Equation 3] and [Equation 4].

Figure 112012002776391-pat00027
Figure 112012002776391-pat00027

Figure 112012002776391-pat00028
Figure 112012002776391-pat00028

여기서, 인버터 출력 전압의 위상각과 부하망 전압의 위상각의 차인 전력각

Figure 112012002776391-pat00029
가 매우 작다고 가정하면
Figure 112012002776391-pat00030
다음의 [수학식 5] 및 [수학식 6]과 같이 표현된다.Here, the power angle which is the difference between the phase angle of the inverter output voltage and the phase angle of the load net voltage
Figure 112012002776391-pat00029
Is very small
Figure 112012002776391-pat00030
(5) and (6) below. &Quot; (6) "

Figure 112012002776391-pat00031
Figure 112012002776391-pat00031

Figure 112012002776391-pat00032
Figure 112012002776391-pat00032

상기 [수학식 5] 및 [수학식 6]에서 유효전력이 인버터 부하망의 출력전압에서 전압의 피크 크기를 뺀 차이 값

Figure 112012002776391-pat00033
에 의존하며, 무효전력이 전력각(
Figure 112012002776391-pat00034
)에 의존한다는 것을 알 수 있고, 이 관계를 이용한 수하제어 관계식은 다음의 [수학식 7] 및 [수학식 8]과 같다.In Equations (5) and (6), the effective power is calculated by subtracting the peak value of the voltage from the output voltage of the inverter load network
Figure 112012002776391-pat00033
And the reactive power depends on the power angle (
Figure 112012002776391-pat00034
), And the subordinate control relation using this relation is expressed by the following equations (7) and (8).

Figure 112012002776391-pat00035
Figure 112012002776391-pat00035

Figure 112012002776391-pat00036
Figure 112012002776391-pat00036

상기 [수학식 7] 및 [수학식 8]에서

Figure 112012002776391-pat00037
는 인버터 출력 전압 지령의 각주파수와 피크값을 의미하고,
Figure 112012002776391-pat00038
은 인버터의 무부하 출력 전압의 각주파수와 피크 크기이며,
Figure 112012002776391-pat00039
는 각각 전압 및 주파수 수하계수이고,
Figure 112012002776391-pat00040
는 인버터가 출력하는 평균 유효전력 및 평균 무효전력(Average Active Power & Reactive Power)이다.
In the equations (7) and (8)
Figure 112012002776391-pat00037
Means the angular frequency and peak value of the inverter output voltage command,
Figure 112012002776391-pat00038
Is the angular frequency and peak amplitude of the no-load output voltage of the inverter,
Figure 112012002776391-pat00039
Lt; / RTI > are voltage and frequency underload coefficients, respectively,
Figure 112012002776391-pat00040
Is the average active power and average reactive power output by the inverter (Average Active Power & Reactive Power).

한편, 도 2는 유효전력-출력전압의 피크값(

Figure 112012002776391-pat00041
) 수하특성으로 두 인버터 m과 k가 같은 무부하 출력 전압의 피크 크기와 같은 유효전력-전압 수하계수
Figure 112012002776391-pat00042
을 가질 때의 수하특성을 나타낸다.On the other hand, Fig. 2 shows the peak value of the active power-output voltage
Figure 112012002776391-pat00041
) Under load characteristics, two inverters m and k have the same effective power-voltage underload coefficient as the peak size of the same no-load output voltage
Figure 112012002776391-pat00042
And the like.

인버터들 사이의 순환 유효전력이 없다는 가정 하에 특성을 설명하면 k 인버터가 유효전력-출력전압의 피크값(

Figure 112012002776391-pat00043
) 수하모드로 부하 상태에서 운전점 B로 결정되어 운전 중일 때 m 인버터가 무부하 수하모드로 운전 중 투입되어 두 인버터가 병렬 운전을 시작하면 수하특성에 의해서 k 인버터의 출력 전압 크기가 증가하면서 유효전력 분담률이 감소한다.Assuming that there is no cyclic effective power between the inverters, the characteristics of the k inverter are expressed as the peak value of the active power-output voltage (
Figure 112012002776391-pat00043
) When the inverter is in operation while it is determined as the operation point B in the load mode and in operation mode, and the inverter is in the no load operation mode. When the two inverters start parallel operation, the output voltage of the inverter increases, The sharing rate decreases.

또한, m 인버터는 출력 전압 크기가 감소하면서 유효전력 분담률이 증가한다. 최종적으로 두 인버터는 전력 분담 평형상태에 이르게 되면서 평형 전압 크기 및 유효전력

Figure 112012002776391-pat00044
를 출력하게 된다.
In addition, the m inverter increases the effective power sharing ratio as the output voltage decreases. Finally, the two inverters reach the power sharing equilibrium state, and the equilibrium voltage magnitude and the active power
Figure 112012002776391-pat00044
.

또한, 도 3은 무효전력-주파수 수하의 부하특성을 도시한 도면으로, 용량성 부하의 경우 음의 무효전력을 가지고 유도성 부하의 경우 양의 무효전력을 가지게 된다.Fig. 3 is a graph showing load characteristics under reactive power-frequency. In the case of a capacitive load, a negative reactive power is obtained, and in the case of an inductive load, a positive reactive power is obtained.

도 3에 도시된 바와 같이, 무효전력-출력전압의 주파수(

Figure 112012002776391-pat00045
) 수하특성으로 두 인버터 m과 k가 같은 무부하 출력 전압의 각주파수 및 같은 무효전력-주파수 수하계수
Figure 112012002776391-pat00046
를 가질 때의 수하특성을 나타내며, 유효전력-출력전압의 피크값(
Figure 112012002776391-pat00047
) 수하특성과는 다르게 수하직선이 양의 기울기를 가진다. 이때, 부하는 양의 무효전력을 가지는 유도성 부하로 가정한다.As shown in FIG. 3, the frequency of the reactive power-output voltage (
Figure 112012002776391-pat00045
) Underwater characteristics, two inverters m and k have the same frequency of the no-load output voltage and the same reactive power-frequency sub-coefficient
Figure 112012002776391-pat00046
, And the peak value of the active power-output voltage (
Figure 112012002776391-pat00047
Unlike the underwater characteristics, the undercut line has a positive slope. At this time, the load is assumed to be an inductive load having a positive reactive power.

또한, k 인버터가 무효전력-출력전압의 주파수(

Figure 112012002776391-pat00048
) 수하모드로 부하 상태에서 운전점 B로 결정되어 운전 중일 때 m 인버터가 무부하 수하모드로 운전 중 투입되어 두 인버터가 병렬운전을 시작하면 수하특성에 의해서 k 인버터의 출력 전압 각주파수가 감소하면서 무효전력 분담률이 감소한다.Also, if the k inverter determines the frequency of the reactive power-output voltage (
Figure 112012002776391-pat00048
) When the inverter is in operation while it is determined as the operation point B in the load mode and the operation point is set to the operation point B while the inverter is in the no load operation mode and the two inverters start parallel operation. The power sharing ratio decreases.

또한, m 인버터는 출력 전압 각주파수가 증가하면서 무효전력 분담률이 증가한다. 최종적으로 두 인버터는 전력 분담 평형상태에 이르게 되면서 평형 각주파수 및 무효전력

Figure 112012002776391-pat00049
를 출력하게 된다.
In addition, the m inverter increases the reactive power sharing ratio as the output voltage angular frequency increases. Finally, the two inverters reach the equilibrium state of the power sharing, and the equilibrium angular frequency and reactive power
Figure 112012002776391-pat00049
.

한편, 도 4는 본 발명에 따른 무효전력-주파수 부하 특성을 도시한 도면이고, 도 5는 본 발명에 따른

Figure 112012002776391-pat00050
, 무효전력-출력전압의 주파수(
Figure 112012002776391-pat00051
) 수하제어의 블록다이어그램을 도시한 도면이다.FIG. 4 is a diagram illustrating a reactive power-frequency load characteristic according to the present invention, and FIG.
Figure 112012002776391-pat00050
, Reactive power - frequency of the output voltage (
Figure 112012002776391-pat00051
) ≪ / RTI >

도 4 및 도 5를 참조하면,

Figure 112012002776391-pat00052
,
Figure 112012002776391-pat00053
수하제어의 블록다이어그램으로 전압과 전류를 측정하여 평균 유효전력 및 평균 무효전력을 계산하고, 유효전력-출력전압의 피크값(
Figure 112012002776391-pat00054
), 무효전력-출력전압의 주파수(
Figure 112012002776391-pat00055
) 수하특성에 의해서 병렬운전을 할 수 있도록 출력 전압의 각주파수와 피크 크기의 지령값을 계산한다.
Referring to Figures 4 and 5,
Figure 112012002776391-pat00052
,
Figure 112012002776391-pat00053
The average effective power and average reactive power are calculated by measuring the voltage and current with the block diagram of the underflow control, and the peak value of the active power-output voltage
Figure 112012002776391-pat00054
), Reactive power - frequency of the output voltage (
Figure 112012002776391-pat00055
) Calculate the command value of the angular frequency and the peak size of the output voltage so that parallel operation can be performed by the underwater characteristics.

이하, 도 6을 참조하여 본 발명에 따른 무선통신을 이용한 UPS 병렬 운전 제어 방법에 대해 살피면 아래와 같다.Hereinafter, a UPS parallel operation control method using wireless communication according to the present invention will be described with reference to FIG.

먼저, 두개의 인버터 각각이 전력 분담 평형상태에 이르는 경우, 평형 전압 크기 및 유효전력

Figure 112012002776391-pat00056
를 도출한다(S10).First, when each of the two inverters reaches the power sharing equilibrium state, the balance voltage magnitude and the active power
Figure 112012002776391-pat00056
(S10).

이어서, 두개의 인버터 각각이 전력 분담 평형상태에 이르는 경우, 평형 각주파수 및 무효전력

Figure 112012002776391-pat00057
를 도출한다(S20).Then, when each of the two inverters reaches the power sharing equilibrium state, the balance angular frequency and the reactive power
Figure 112012002776391-pat00057
(S20).

뒤이어, 유효전력-출력전압의 피크값(

Figure 112012002776391-pat00058
), 무효전력-출력전압의 주파수(
Figure 112012002776391-pat00059
) 수하제어의 블록다이어그램을 통해 두 개의 인버터 각각에 대한 전압과 전류를 측정한다(S30).Subsequently, the peak value of the active power-output voltage (
Figure 112012002776391-pat00058
), Reactive power - frequency of the output voltage (
Figure 112012002776391-pat00059
) The voltage and current for each of the two inverters is measured through a block diagram of the underflow control (S30).

그리고, 두 개의 인버터 각각에 대한 평균 유효전력 및 평균 무효전력을 계산하고, 출력 전압의 각주파수와 피크 크기의 지령값을 계산하여 유효전력-출력전압의 피크값(

Figure 112012002776391-pat00060
), 무효전력-출력전압의 주파수(
Figure 112012002776391-pat00061
) 수하특성에 의해서 병렬운전을 제어한다(S40).
Then, the average effective power and the average reactive power for each of the two inverters are calculated, and the command value of each frequency and peak size of the output voltage is calculated to calculate the peak value of the effective power-output voltage
Figure 112012002776391-pat00060
), Reactive power - frequency of the output voltage (
Figure 112012002776391-pat00061
(S40). ≪ / RTI >

한편, 도 7을 참조하여 본 발명에 따른 무선통신을 이용한 UPS 병렬 운전 제어 방법의 제S10단계 이전 과정을 살피면 아래와 같다.Referring to FIG. 7, the process of step S10 of the UPS parallel operation control method using wireless communication according to the present invention will be described below.

제S10단계 이전에, 인버터의 출력전압으로부터 부하망으로 인가되는 유효전력 및 무효전력을 상기 [수학식 1] 및 [수학식 2]를 통해 도출한다(S50).Before step S10, the active power and the reactive power applied to the load network from the output voltage of the inverter are derived through the above-described equations (1) and (2) (S50).

이어서, 인버터의 출력전압으로부터 부하망에 인가된 유효전력 및 무효전력으로부터 출력임피던스를 상기 [수학식 3] 및 [수학식 4]를 통해 도출한다(S60).Subsequently, the output impedance from the active power and the reactive power applied to the load network is derived from the output voltage of the inverter through the above-described equations (3) and (4) (S60).

뒤이어, [수학식 5] 및 [수학식 6]을 통해 유효전력이

Figure 112012002776391-pat00062
에 의존하고, 무효전력이 전력각(
Figure 112012002776391-pat00063
)에 의존하는 것을 도출한다(S70).Subsequently, through the equations (5) and (6), the effective power
Figure 112012002776391-pat00062
, And the reactive power is determined by the power angle (
Figure 112012002776391-pat00063
(Step S70).

그리고, 도출된 유효전력과 무효전력을 [수학식 7] 및 [수학식 8]의 수하제어 관계식에 의해 인버터 출력 전압 지령의 각주파수 및 피크값을 도출하고 제S10단계로 그 절차를 이행한다(S80).Then, the derived frequency and peak value of the inverter output voltage command are derived from the derived effective power and reactive power using the underwater control relational expressions of Equations (7) and (8), and the procedure is executed in Step S10 S80).

이상으로 본 발명의 기술적 사상을 예시하기 위한 바람직한 실시예와 관련하여 설명하고 도시하였지만, 본 발명은 이와 같이 도시되고 설명된 그대로의 구성 및 작용에만 국한되는 것이 아니며, 기술적 사상의 범주를 일탈함이 없이 본 발명에 대해 다수의 변경 및 수정이 가능함을 당업자들은 잘 이해할 수 있을 것이다. 따라서 그러한 모든 적절한 변경 및 수정과 균등 물들도 본 발명의 범위에 속하는 것으로 간주되어야 할 것이다.While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It will be appreciated by those skilled in the art that numerous changes and modifications may be made without departing from the invention. And all such modifications and changes as fall within the scope of the present invention are therefore to be regarded as being within the scope of the present invention.

Figure 112012002776391-pat00064
: 인버터 부하망의 출력전압, 전압의 피크 크기
Figure 112012002776391-pat00065
: 전력각
Figure 112012002776391-pat00066
: 출력 임피던스의 크기
Figure 112012002776391-pat00067
: 위상각
Figure 112012002776391-pat00068
: 유효전력-출력전압의 피크값
Figure 112012002776391-pat00069
: 무효전력-출력전압의 주파수
Figure 112012002776391-pat00070
: 인버터 출력 전압 지령의 각주파수와 피크값
Figure 112012002776391-pat00071
: 인버터의 무부하 출력 전압의 각주파수와 피크 크기
Figure 112012002776391-pat00072
: 각각 전압 및 주파수 수하계수
Figure 112012002776391-pat00073
: 인버터가 출력하는 평균 유효전력 및 평균 무효전력
Figure 112012002776391-pat00064
: Output voltage of inverter load network, Peak size of voltage
Figure 112012002776391-pat00065
: Power angle
Figure 112012002776391-pat00066
: Size of output impedance
Figure 112012002776391-pat00067
: Phase angle
Figure 112012002776391-pat00068
: Active power - Peak value of output voltage
Figure 112012002776391-pat00069
: Reactive power - frequency of output voltage
Figure 112012002776391-pat00070
: Each frequency and peak value of inverter output voltage command
Figure 112012002776391-pat00071
: The frequency and peak size of the inverter's no-load output voltage
Figure 112012002776391-pat00072
: Voltage and frequency under load factor
Figure 112012002776391-pat00073
: Average effective power and average reactive power output by the inverter

Claims (2)

무선통신을 이용한 UPS 병렬 운전 제어 방법에 있어서,
(a) 두개의 인버터 각각이 전력 분담 평형상태에 이르는 경우, 평형 전압 크기 및 유효전력(
Figure 112013011810324-pat00074
)을 도출하는 단계;
(b) 두개의 인버터 각각이 전력 분담 평형상태에 이르는 경우, 평형 각주파수 및 무효전력(
Figure 112013011810324-pat00075
) 도출하는 단계;
(c)
Figure 112013011810324-pat00076
,
Figure 112013011810324-pat00077
수하제어의 블록다이어그램을 통해 두 개의 인버터 각각에 대한 전압과 전류를 측정하는 단계; 및
(d) 두 개의 인버터 각각에 대한 평균 유효전력 및 평균 무효전력을 계산하고, 출력 전압의 각주파수와 피크 크기의 지령값을 계산하여
Figure 112013011810324-pat00078
수하특성에 따라 병렬운전을 제어하는 단계;를 포함하되,
상기 (a) 단계 이전에,
(d) 인버터의 출력전압으로부터 부하망으로 인가되는 유효전력 및 무효전력을 [수학식 1] 및 [수학식 2]를 통해 도출하는 단계;
(e) 인버터의 출력전압으로부터 부하망에 인가된 유효전력 및 무효전력으로부터 출력임피던스를 [수학식 3] 및 [수학식 4]를 통해 도출하는 단계;
(f) [수학식 5] 및 [수학식 6]을 통해 유효전력이 인버터 부하망의 출력전압에서 전압의 피크 크기를 뺀 차이 값
Figure 112013011810324-pat00079
에 의존하고, 무효전력이 전력각(
Figure 112013011810324-pat00080
)에 의존하는 것을 도출하는 단계; 및
(g) 도출된 유효전력과 무효전력을 [수학식 7] 및 [수학식 8]의 수하제어 관계식에 의해 인버터 출력 전압 지령의 각주파수 및 피크값을 도출하는 단계;를 포함하는 것을 특징으로 하는 무선통신을 이용한 UPS 병렬 운전 제어 방법.
Figure 112013011810324-pat00081
.......................................[수학식 1]
Figure 112013011810324-pat00082
.......................................[수학식 2]
Figure 112013011810324-pat00083
...........................................[수학식 3]
Figure 112013011810324-pat00084
.............................................[수학식 4]
Figure 112013011810324-pat00085
...............................................[수학식 5]
Figure 112013011810324-pat00086
.................................................[수학식 6]
Figure 112013011810324-pat00087
.............................................[수학식 7]
Figure 112013011810324-pat00088
..........................................[수학식 8]
상기
Figure 112013011810324-pat00089
는 인버터 출력전압의 부하망 전압의 피크 크기(Peak-amplitude)이고,
Figure 112013011810324-pat00090
는 전력각(Power Angle)이며,
Figure 112013011810324-pat00091
와
Figure 112013011810324-pat00092
는 출력 임피던스의 크기(Magnitude)와 위상각(Phase Angle)이고, 상기
Figure 112013011810324-pat00093
는 인버터 출력 전압 지령의 각주파수와 피크값을 의미하고,
Figure 112013011810324-pat00094
은 인버터의 무부하 출력 전압의 각주파수와 피크 크기이며,
Figure 112013011810324-pat00095
는 각각 전압 및 주파수 수하계수이고,
Figure 112013011810324-pat00096
는 인버터가 출력하는 평균 유효전력 및 평균 무효전력이다.A method of controlling parallel operation of a UPS using wireless communication,
(a) When each of the two inverters reaches a power sharing equilibrium state, the equilibrium voltage magnitude and the effective power (
Figure 112013011810324-pat00074
);
(b) When the two inverters reach the power sharing equilibrium state, the balance angular frequency and reactive power (
Figure 112013011810324-pat00075
);
(c)
Figure 112013011810324-pat00076
,
Figure 112013011810324-pat00077
Measuring voltage and current for each of the two inverters through a block diagram of the underflow control; And
(d) Calculate the average effective power and mean reactive power for each of the two inverters, and calculate the command value of each frequency and peak size of the output voltage
Figure 112013011810324-pat00078
And controlling the parallel operation according to the loading characteristics,
Before the step (a)
(d) deriving the effective power and the reactive power applied from the output voltage of the inverter to the load network through Equations (1) and (2);
(e) deriving the output impedance from the active power and the reactive power applied to the load network from the output voltage of the inverter through (3) and (4);
(f) Using Equation (5) and Equation (6), the difference between the output voltage of the inverter load network and the peak power of the voltage
Figure 112013011810324-pat00079
, And the reactive power is determined by the power angle (
Figure 112013011810324-pat00080
Gt; dependent < / RTI > And
(g) deriving the angular frequency and the peak value of the inverter output voltage command by using the derived active control power and the reactive power according to the underwater control relation expressions of Equation (7) and (8) A UPS parallel operation control method using wireless communication.
Figure 112013011810324-pat00081
... " (1)
Figure 112013011810324-pat00082
... " (2) "
Figure 112013011810324-pat00083
... " (3) "
Figure 112013011810324-pat00084
... " (4) "
Figure 112013011810324-pat00085
................................................. [ 5]
Figure 112013011810324-pat00086
................................................. [ (6)
Figure 112013011810324-pat00087
... " (7) "
Figure 112013011810324-pat00088
... " (8) "
remind
Figure 112013011810324-pat00089
Is the peak-amplitude of the load voltage of the inverter output voltage,
Figure 112013011810324-pat00090
Is the power angle,
Figure 112013011810324-pat00091
Wow
Figure 112013011810324-pat00092
(Magnitude) and a phase angle (phase angle) of the output impedance,
Figure 112013011810324-pat00093
Means the angular frequency and peak value of the inverter output voltage command,
Figure 112013011810324-pat00094
Is the angular frequency and peak amplitude of the no-load output voltage of the inverter,
Figure 112013011810324-pat00095
Lt; / RTI > are voltage and frequency underload coefficients, respectively,
Figure 112013011810324-pat00096
Is an average effective power and an average reactive power output from the inverter. 삭제delete
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