KR20190112222A - Apparatus for Hybrid Uninterruptible Power Supplying for EV Using Robust Tracking Control - Google Patents

Abstract

Disclosed are a hybrid uninterruptible power supplying device using robust tracking control and an uninterruptible power supplying method. The hybrid uninterruptible power supplying device comprises: a bidirectional charging unit including a filter unit filtering a high frequency with regard to alternating current (AC) power of an external power system including an inductor and a three-phase converter including at least one IGBT switch to convert three-phase AC voltage into direct current (DC) voltage and charging a battery from the external power system or transferring the power from the battery to the external power system; a measurement unit measuring the voltage of the battery and three-phase current and three-phase voltage of the bidirectional charging unit; and a control unit referring to a measurement result of the measurement unit and a power transferring direction of the bidirectional charging unit to output a control signal of controlling current of the inductor.

Description

Hybrid Uninterruptible Power Supply for EV Using Robust Tracking Control

The present invention relates to a hybrid type uninterruptible power supply using robust tracking control.

The contents described in this section merely provide background information on the present embodiment and do not constitute a prior art.

The demand for uninterrupted power supplies (UPS) is increasing due to the increasing use of various digital information devices, such as industrial high-tech equipment, computers, and office equipment, which are sensitive to power failures and voltage fluctuations of commercial power.

The main function of an uninterruptible power supply is to supply AC power with a constant frequency and a constant voltage regardless of linear and nonlinear loads and load fluctuations. It should have stable and excellent control performance and harmonic suppression performance. The load of the uninterruptible power supply is a diode full-wave rectifier of a DC load such as a computer, and since these nonlinear loads generate harmonics, the voltage and current are distorted, so the uninterruptible power supply has a clean sinusoidal voltage even under various loads. The ability to supply is required.

Therefore, when applying the uninterruptible power supply, it is very important to properly control the output voltage while maintaining other state variables at a constant level under control input voltage limitation and load fluctuation. In general, the output voltage of the uninterruptible power supply is controlled by a dual-loop strategy including an inner loop, which is a current control loop, and an outer loop, which is a voltage control loop.

Looking at the related art, the internal loop current controller has an important effect on closed-loop performance, so that proportional integral (PI) control and deadbeat control are required for the current controller design. Various control methods such as control have been applied. On the other hand, the voltage controller of the outer loop is applied with the traditional proportional integral control method.

The present invention has a main object as a method for controlling the output of an uninterruptible power supply, and provides a double loop control method through robust tracking control.

According to an embodiment of the present invention, a three-phase converter for converting a three-phase AC voltage into a DC voltage, including an inductor including a filter unit for filtering high frequency to the AC power of the external power system and at least one IGBT switch A bidirectional charging unit configured to charge a battery from the external power system or to transfer power from the battery to the external power system; A measuring unit measuring a voltage of the battery, a three-phase current and a three-phase voltage of the bidirectional charging unit; And a controller configured to output a control signal for controlling a current of the inductor by referring to a measurement result of the measurement unit and a power transfer direction of the bidirectional charging unit.

Embodiments of the hybrid type uninterruptible power supply for an electric vehicle may further include one or more of the following features.

When the bidirectional charging unit charges the battery, the controller performs double loop control, but controls the current of the inductor through an internal loop control using robust tracking control and a battery through an external loop control. A reference power value for power delivered to the external power system when a reference value of the inductor current is generated to maintain a constant charge current or charge voltage, and the bidirectional charging unit discharges the battery; Set and output the control signal for supplying the reference power value.

According to an embodiment of the present invention, a three-phase converter for converting a three-phase AC voltage into a DC voltage, including an inductor including a filter unit for filtering high frequency to the AC power of the external power system and at least one IGBT switch And a bidirectional charging unit which charges the battery from an external power system or transfers power from the battery to the external power system to control charging in both directions, and measures the voltage of the battery, the three-phase current and the three-phase voltage of the battery. Process of doing; And outputting a control signal for controlling the current of the inductor included in the filter unit of the bidirectional charging unit by referring to the measured voltage of the battery and the power transfer direction of the bidirectional charging unit. Provide a method.

As described above, according to the present embodiment, by using the robust control method for output control of the uninterruptible power supply, the output can be stably controlled.

In addition, by using robust control without using a DC-DC converter as an interface between the three-phase AC-DC converter and the battery of the bi-directional charging, it is possible to provide fast charging performance of the battery through the existing constant current-constant voltage charging mode There is.

1 is a view schematically illustrating a bidirectional power transfer system including a bidirectional charging unit having an L filter and a converter according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating battery discharge mode control in a robust tracking control method of a hybrid type uninterruptible power supply according to an embodiment of the present invention.
3 is a block diagram illustrating battery CV charging mode control in a robust tracking control method of a hybrid type UPS.
4 is a block diagram illustrating battery CC charging mode control in a robust tracking control method of a hybrid type UPS.
5 is a circuit diagram of a hybrid type uninterruptible power supply according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. Throughout the specification, when a part is said to include, 'include' a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated. . In addition, the terms '~', 'module', etc. described in the specification mean a unit for processing at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention.

The present invention proposes a method of controlling through robust tracking control without using a DC-DC converter as an interface between a three-phase AC-DC converter and a battery. By the hybrid type uninterruptible power supply according to the present embodiment, the battery is charged with constant current until the voltage reaches the recommended maximum voltage, and then the voltage is kept constant until the current consumed by the battery drops to the residual value. Conversely, during discharge mode of operation, energy stored in the battery can be transferred back to the power grid.

Further, in one embodiment of the present invention, robust control using state feedback for performing the integral operation for both charging and discharging is done in the dq-sync frame. The set of stabilizing gains of this robust control is determined by linear matrix inequality (LMI) based optimization, which minimizes the convergence time to steady state when parametric uncertainty in the L filter occurs.

In addition, in one embodiment of the present invention, in the case of charge control, an external loop PI controller is used to maintain the DC current and the DC voltage for CC and CV control, respectively, and to obtain an existing phase synchronization to obtain an external power system voltage phase angle. Use a loop (PLL).

1 is a view schematically illustrating a bidirectional power transfer system including a bidirectional charging unit having an L filter and a converter according to an embodiment of the present invention.

Referring to FIG. 1, the entire system includes an external power system 110, a bidirectional charging unit, and a battery 140. The bidirectional charging unit includes a filter unit 120 and a three-phase converter unit 130. The filter unit 120 includes three inductors. The three-phase converter unit 130 is composed of at least one IGBT switch to convert the AC power passing through the filter unit 120 into DC power.

Bidirectional charging unit of the present invention is a configuration capable of power transfer in both directions. That is, in one embodiment of the present invention, the bi-directional charging unit is connected to the external power system 110 and the battery 140 to convert the AC power input from the external power system 110 to DC to supply to the battery 140. The DC power input from the battery 140 may be converted and output to the external power system 110. In addition, the bidirectional charging unit performs robust control for power transfer to the external power system 110 and battery charging. Specifically, the bidirectional charging unit is controlled by applying a control signal to the gate of the IGBT switch included in the three-phase converter unit 130. Power transfer will be performed.

The battery 140 is a component for providing a high power direct current to an electric motor or the like in an eco-friendly vehicle driven by electrical energy, such as a plug-in hybrid vehicle or an electric vehicle. The battery 140 may be charged by receiving power provided from the external power system 110 through a charging device built in the vehicle. In addition, the battery 140 may output power stored when the vehicle is driven to supply power to the driving motor of the vehicle.

In the bidirectional power transfer system including the bidirectional charging unit illustrated in FIG. 1, the line current is expressed by the abc-axis as follows.

(1)

(One)

이고,

은 외부전력계통(110)의 최대 출력 전압이고, 3상 컨버터부(130)의 스위치는

와 같이 표시된다. here,

ego,

Is the maximum output voltage of the external power system 110, the switch of the three-phase converter 130

Is displayed as:

The dynamics represented by the abc-axis in (1) can be converted to the dq-axis as follows.

(2)

(2)

,

,

,

,

,

이고, ω는 AC 전압 공급원의 각주파수이다.At this time,

,

,

,

,

,

Is the angular frequency of the AC voltage source.

및 제어 입력 신호

는 다음과 같은 관계를 만족한다. Inductor Current in dq-Frame

And control input signal

Satisfies the following relationship:

(3)

(3)

(4)

(4)

,

이다.here,

,

to be.

은 다음과 같은 역학관계를 만족한다.On the other hand, the battery voltage in (2)

Satisfies the following dynamics:

(5)

(5)

(6)At this time,

(6)

는 컨버터 전류,

는 배터리로의 출력 전류이다.ego,

Is the converter current,

Is the output current to the battery.

는 다음과 같이 제한된 범위를 갖는다.Control input variables

Has a limited range as follows.

(7)

(7)

In addition, the relational expression of (2) can be expressed as follows using the sampling period h.

(8)

(8)

,

,

,

이고,

,

이다.here,

,

,

,

ego,

,

to be.

The following describes the uncertainty and offset-free control of the system.

First, assume that L and R have the following limited ranges.

(9a)

(9a)

(9b)

(9b)

Here, the matrix ( A , B ) corresponds to four possible combinations of invariant values ( A _i , B _i ) (i = 1,2,3,4) of 1 / L and 1 / R, and the matrix ( A , B ) belongs to the polytopic uncertainty set Ψ defined as

(10)

10

Uncertainty of the system may vary depending on the setting but must be within the range of (9). Therefore, the uncertainty range of the system is defined as follows.

(11a)

(11a)

(11b)

(11b)

와

는 각각 필터 저항과 인덕턴스의 공칭값(nominal value)이며 μμ (> 1)는 튜닝 파라미터로 간주한다. here,

Wow

Are the nominal values of filter resistance and inductance, respectively, and μμ (> 1) is regarded as the tuning parameter.

라 하면, 제어 법칙에 따라 다음과 같이 나타낼 수 있다.Based on the reference power to be supplied to the external power system 110, the inductor current reference signal of the controller for supplying the reference power

In this case, it can be expressed as follows according to the control law.

(12)

(12)

Where K is the state feedback gain And L is the integrator gain. From the integrator of (12), if the closed loop system is stable, the error in the steady state of the reference signal x _ref and the external power system 110 current x is zero. The reference signal x _ref is defined differently according to the operation mode. That is, the reference signal x _ref is generated by the outer loop controller in the charging mode and calculated from the given reference power in the discharge mode.

When the state feedback gain K and the integrator gain L are stabilized by using the linear matrix inequality (LMI), the following relationship can be obtained from (8) and (12).

(13)

(13)

이고,

이고,

이고,

이고,

이다.At this time,

ego,

ego,

ego,

ego,

to be.

The control input u ( k ) can be represented as follows.

(14)

(14)

To obtain the gain F in the stabilized state, assuming D ( k ) = 0, the outer loop system can be expressed as

(15)

(15)

The closed loop system shown in (15) can be said to be stable when the following positive definition matrix W exists.

,

(16)

,

(16)

(17)

(17)

By applying Schur complement and uncertainty sets 10 to 17, the following can be obtained.

, (i = 1,……,4), (18)

, (i = 1, ……, 4), (18)

,

,

,

,

, (i = 1, 2, 3, 4)이다.At this time,

,

,

,

,

, (i = 1, 2, 3, 4).

,

및 행렬

가 존재할 때, 점근적으로 안정하게 된다. 이 때의 안정 이득은 다음과 같이 주어진다.In other words, the closed loop system of (15) is a symmetric positive probability matrix with (18)

,

And matrices

When present, it becomes asymptotically stable. The stable gain at this time is given by:

(19)

(19)

를 가정하거나, 다음을 가정한다.

Or assume the following.

(20)

20

Given αα as a small value, z is expected to converge quickly to the origin. Therefore, by using a program such as the MATLAB toolbox, the following optimization problem can be solved to obtain an optimal gain that minimizes convergence time.

(21)Given (18) and (20)

(21)

FIG. 2 is a block diagram illustrating battery discharge mode control in a robust tracking control method of a hybrid type uninterruptible power supply according to an embodiment of the present invention.

When the power is supplied to the external power system 110, the desired power supply amount is obtained as a set value, and the modified power is applied to the inductor current value supplied to the system, and then robust control is applied.

The battery discharge mode in the robust tracking control method of the hybrid type uninterruptible power supply according to an embodiment of the present invention includes a state calculation unit 210, a robust control unit 220, a space vector pulse width modulator 230, and AC / DC charging. The device 240, the measurement unit 250, and the rotation coordinate system conversion unit 260 are implemented.

The state calculator 210 performs an optimization operation as shown in FIG. 21 to supply reference power to the external power system 110.

을 전달할 수 있도록 3상 컨버터부(130)의 스위칭 동작을 제어한다. The robust control unit 220 outputs a control signal from the measurement unit 250 using the battery voltage and the three-phase current and three-phase voltage inside the charging device. The robust control unit 220 has a reference power constant in the battery charging device to the external power system 110 in the discharge control mode.

To control the switching operation of the three-phase converter unit 130 to deliver.

The space vector pulse width modulator 230 receives a control input and outputs an actual control signal to the three-phase converter 130 of the bidirectional charging unit. The spatial vector pulse width modulator 230 and the rotation coordinate system transform unit 260 for transforming coordinates between frames of various measurement signals and control signals used for output power control are well known in the art. Since the description of the, detailed description thereof will be omitted.

을 전달하기 위한 기준 신호

를 출력하기 위한 계산 과정을 설명한다.Hereinafter, the reference power in the robust control unit 220 according to an embodiment of the present invention

Reference signal to convey

It describes the calculation process for outputting the.

The instantaneous active power and reactive power of the external power system 110 represented by αβ -frame are as follows.

(22)

(22)

는 αβ-프레임에서의 외부전력계통(110) 전류,

는 αβ-프레임에서의 외부전력계통(110) 전압이고,

는 외부전력계통(110) 유효 전력,

는 외부전력계통(110) 무효 전력이다.here,

Is the current of the external power system 110 in the αβ -frame ,

Is the voltage of the external power system 110 in the αβ -frame ,

The external power system 110 active power,

Is the external power system 110 reactive power.

If you convert it to a dq-frame, it is expressed as

(23)

(23)

는 dq-프레임에서의 외부전력계통(110) 전류,

는 dq-프레임에서의 외부전력계통(110) 전압이다. (23)으로부터, 외부전력계통(110) 전류는 다음과 같이 계산된다.

Is the current of the external power system 110 in the dq-frame,

Is the external power system 110 voltage in the dq-frame. From 23, the external power system 110 current is calculated as follows.

(24)

(24)

Or, it can be represented as follows.

(25)

(25)

In order to maintain the unit power factor, the reactive power is removed and the reference signal is calculated again.

(26)

(26)

이다.here,

to be.

를 이용하여 충전 장치는 일정한 전력

을 외부전력계통(110)에 전달할 수 있다. 즉, 음의 기준 전력을 생성하여 배터리에서 외부전력계통(110)로 향하는 역전류를 만들어낼 수 있다. 기준 전력이 양의 값이라면 배터리를 충전할 수 있다. 더욱이, (25)의

및

를 조정함으로써 유효 전력 및 무효 전력을 직접 조정할 수 있으며, 기준 신호를 얻을 수 있다.Reference signal

Charging device using constant power

It can be delivered to the external power system 110. That is, a negative reference power may be generated to generate a reverse current from the battery to the external power system 110. If the reference power is positive, the battery can be charged. Moreover, of (25)

And

By adjusting, the active power and reactive power can be directly adjusted, and a reference signal can be obtained.

Hereinafter, a battery charging process will be described.

In this embodiment, in order to perform the battery charging process, the constant voltage mode is followed by the constant current mode. The battery charges with a constant current until the voltage reaches the recommended maximum voltage, allowing the voltage to remain constant when the current consumed by the battery drops to a certain residual value. In the charging mode according to the present embodiment, the double loop control strategy is applied to the constant current-constant voltage charging mode. That is, the outer loop control generates an appropriate reference signal x _ref according to the CV or CC control target, and derives x at (8) following the reference signal x _ref via the inner loop control 12.

를 일정하게 유지하거나(CC)

를 일정하게 유지하는(CV) 제어를 이중루프 제어를 통해서 수행한다. 즉 인덕터 전류를 제어하는 내부 루프의 강인제어를 설계하고 원하는 배터리 전류와 전압을 얻기 위해서 인덕터 전류의 설정치를 만들어 내는 외부 PID 제어기를 구성한다. At the time of charge

Is kept constant (CC)

Control is maintained through double loop control. In other words, we design robust control of the inner loop that controls the inductor current and construct an external PID controller that generates the set value of the inductor current to obtain the desired battery current and voltage.

3 is a block diagram illustrating battery CV charging mode control in a robust tracking control method of a hybrid type UPS.

In the CV charging mode of the battery in the robust tracking control method of the three-phase hybrid uninterruptible power supply according to an embodiment of the present invention, the CV charging mode may include a PI controller 310, a robust controller 320, and a space vector pulse width modulator ( 330, the AC / DC charging device 340, the measuring unit 350, and the rotary coordinate system conversion unit 360 are implemented.

은 다음과 같다.Hereinafter, the outer loop PI control for constant voltage charging will be described. Output of outer loop control

Is as follows.

(27)

(27)

는 배터리 충전을 위한 기준 정전압이고,

는 출력 전압이다. 또한, 앞서 설명한 내부 루프 제어가 충분히 빠르기 때문에, 어떤 기준 전류

에 대하여 다음과 같이 가정할 수 있다.here,

Is the reference constant voltage for battery charging,

Is the output voltage. Also, because the internal loop control described earlier is fast enough, some reference current

Can be assumed as follows.

(28)

(28)

Through (5) to (28), the following equation can be derived.

(29)

(29)

(30)

(30)

및

은 다항식(30)의 특성을 고려하여 다음과 같이 표현할 수 있다.benefit

And

In consideration of the properties of the polynomial (30) can be expressed as follows.

(31)

(31)

및

를 도입하여 다음과 같이 표현할 수 있다.Specific value

And

By introducing, we can express

(32)

(32)

(33)

(33)

를 생성하는 출력 루프 제어부로 피드백된다. 제어부에서는 기존의 PLL(Phased-Locked Loop)를 이용하여 외부전력계통(110) 전압의 위상각을 얻는다.As shown in Figure 3, the battery voltage is the reference current

Is fed back to the output loop control unit to generate the. The control unit obtains the phase angle of the voltage of the external power system 110 using the conventional PLL (Phased-Locked Loop).

4 is a block diagram illustrating battery CC charging mode control in a robust tracking control method of a hybrid type UPS.

The battery CC charging mode in the robust tracking control method of the hybrid type uninterruptible power supply according to an embodiment of the present invention includes a PI controller 410, a robust controller 420, a space vector pulse width modulator 430, and AC / DC. The charging device 440, the measuring unit 450, and the rotation coordinate system conversion unit 460 are implemented.

를 생성한다. 제안된 CC 충전 제어의 제어 구조는 도 4에 도시된 바와 같다.In the constant current charging phase, the battery pack is charged with a constant current until the voltage reaches the recommended maximum voltage and then switched to the constant voltage charging phase. Reference signal for inner loop robust control with the same concept as CV charging described above using outer loop PI for control of this constant current charge mode.

Create The control structure of the proposed CC charging control is as shown in FIG.

Since the CV charging mode control structure described with reference to FIG. 3 and the CC charging mode control as shown in FIG. 4 are the same except that the outer loop feedback values are the CC and CV charging modes, respectively, detailed description thereof will be omitted.

5 is a circuit diagram of a hybrid type uninterruptible power supply according to an embodiment of the present invention.

Referring to the drawings, the hybrid type uninterruptible power supply according to an embodiment of the present invention further comprises a three-phase inverter unit for performing robust tracking control. Hybrid type uninterruptible power supply according to an embodiment of the present invention can supply voltage to the load connected to the uninterruptible power supply or charge the battery, and provide the power of the battery to the load through the robust tracking control as described above. .

The above description is merely illustrative of the technical idea of the present embodiment, and those skilled in the art to which the present embodiment belongs may make various modifications and changes without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical idea of the present embodiment but to describe the present invention, and the scope of the technical idea of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present embodiment.

110: external power system
120: filter unit
130: three-phase converter
140: battery

Claims (10)

And a three-phase converter for converting a three-phase AC voltage into a DC voltage, including a filter unit for filtering a high frequency of an AC power source of an external power system, including an inductor, and at least one IGBT switch. A bidirectional charging unit for charging a battery or transferring power from the battery to the external power system;
A measuring unit measuring a voltage of the battery, a three-phase current and a three-phase voltage of the bidirectional charging unit; And
A control unit for outputting a control signal for controlling the current of the inductor with reference to the measurement results of the measurement unit and the power transfer direction of the bidirectional charging unit
Hybrid type uninterruptible power supply comprising a. The method of claim 1,
The control unit,
When the bidirectional charging unit performs the operation of charging the battery, the dual loop control is performed, but the current of the inductor is controlled through an internal loop control using robust tracking control and a battery charging current or charging through an external loop control. Generate a reference value for the current of the inductor to keep the voltage constant,
When the bidirectional charging unit discharges the battery, the reference power value for the power delivered to the external power system is set, and the control signal for supplying the reference power value is output. Hybrid uninterruptible power supply. The method of claim 2,
When the bidirectional charging unit performs the operation of discharging the battery, the instantaneous active power and the reactive power of the external power system represented by αβ -frame

Given by

Is the external power system current in αβ -frame ,

Is the external power system voltage in αβ -frame ,

External power system active power,

Is the reactive power of external power system,

,

Is the external power system current in the dq-frame,

Is the external power system voltage in dq-frame,
The reference power value

The control signal for transmitting

Hybrid type uninterruptible power supply, characterized in that the output to satisfy the above formula. The method of claim 2,
When the bidirectional charging unit performs an operation for charging the battery,
In the abc-frame, the internal current of the bidirectional charging unit satisfies the following formula,

here,

ego,

Is the maximum output voltage of the external power system, the switch of the three-phase converter

Given by
The dynamics represented by the abc-axis are converted to the dq-axis as

,

,

,

,

,

Ω is the angular frequency of the AC voltage source,
Inductor Current in dq-Frame

And control input signal

Is

Is,
here,

,

Given by
Voltage of the battery

silver

when,
here,

Is the converter current,

Is the output current to the battery,
By using the sampling period h, if the dynamic relationship of the two-way charging section

Is the same as
here,

,

,

,

ego,

,

ego,
The control signal for supplying the reference power value based on the reference power value to be supplied to the external power system

Say,

Given by
Where K is the state feedback gain And L is the integrator gain,
The control unit,
Hybrid type uninterruptible power supply, characterized in that for outputting the control signal to satisfy the above equation through the internal loop control. The method of claim 4, wherein
Output of outer loop control

this

Given by
here,

Is the reference constant voltage for charging the battery,

Is the output voltage of the battery,

Assuming,

When given as
here,

And

silver

Satisfy a formula such as

,

Is,
The voltage of the battery

Is fed back to the control unit to generate a voltage, and the control unit obtains a voltage phase angle of the external power system using a phase-locked loop (PLL).
The control unit,
Hybrid uninterruptible power supply, characterized in that for outputting the control signal to satisfy the above equation through the external loop control. And a three-phase converter for converting a three-phase AC voltage into a DC voltage, including at least one IGBT switch, and a filter unit for filtering a high frequency of an AC power source of an external power system including an inductor. As a method for controlling the charging in both directions to charge the two-way charging unit or to transfer power from the battery to the external power system,
Measuring the voltage of the battery, the three-phase current and the three-phase voltage of the bidirectional charging unit; And
A process of outputting a control signal for controlling the current of the inductor included in the filter unit of the bidirectional charging unit by referring to the measured voltage of the battery and the power transfer direction of the bidirectional charging unit;
Uninterruptible power supply method of a hybrid uninterruptible power supply comprising a. The method of claim 6,
The control process,
When the bidirectional charging unit performs the operation of charging the battery, the dual loop control is performed, but the current of the inductor is controlled through an internal loop control using robust tracking control and a battery charging current or charging through an external loop control. Generate a reference value for the current of the inductor to keep the voltage constant,
When the bidirectional charging unit discharges the battery, the reference power value for the power delivered to the external power system is set, and the control signal for supplying the reference power value is output. Hybrid type uninterruptible power supply control method. The method of claim 7, wherein
When the bidirectional charging unit performs the operation of discharging the battery, the instantaneous active power and the reactive power of the external power system represented by αβ -frame

Given by

Is the external power system current in αβ -frame ,

Is the external power system voltage in αβ -frame ,

External power system active power,

Is the reactive power of external power system,

,

Is the external power system current in the dq-frame,

Is the external power system voltage in dq-frame,
The control process,
The reference power value

The control signal for transmitting

Control method of a hybrid type uninterruptible power supply, characterized in that the output to satisfy the above formula. The method of claim 7, wherein
When the bidirectional charging unit performs an operation for charging the battery,
In the abc-frame, the internal current of the bidirectional charging unit satisfies the following formula,

here,

ego,

Is the maximum output voltage of the external power system, the switch of the three-phase converter

Given by
The dynamics represented by the abc-axis are converted to the dq-axis as

,

,

,

,

,

Ω is the angular frequency of the AC voltage source,
Inductor Current in dq-Frame

And control input signal

Is

Is,
here,

,

Given by
Voltage of the battery

silver

when,
here,

Is the converter current,

Is the output current to the battery,
By using the sampling period h, if the dynamic relationship of the two-way charging section

Is the same as
here,

,

,

,

ego,

,

ego,
The control signal for supplying the reference power value based on the reference power value to be supplied to the external power system

Say,

Given by
Where K is the state feedback gain And L is the integrator gain,
The control process,
The control method of the hybrid type uninterruptible power supply, characterized in that for outputting the control signal to satisfy the above equation through the internal loop control. The method of claim 9,
Output of outer loop control

this

Given by
here,

Is the reference constant voltage for charging the battery,

Is the output voltage of the battery,

Assuming,

When given as
here,

And

silver

Satisfy a formula such as

,

Is,
The control process,
The voltage of the battery

It is fed back to generate a, and when using the PLL (Phased-Locked Loop) to obtain the voltage phase angle of the external power system, and outputs the control signal to satisfy the above equation through the external loop control Control method of hybrid uninterruptible power supply.

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