JP4459602B2 - Converter output / phase control method - Google Patents

Description

  The present invention relates to a converter output / phase control method.

The present invention relates to a converter that converts AC power into DC power, and has a function of changing the power factor on the AC side. As an example, an inductive current collector that is being studied as an on-board power source for a superconducting magnetically levitated railway will be described.
Conventionally, an induction current collector using a harmonic magnetic field generated by a ground coil has been studied as an on-vehicle power source for a superconducting magnetic levitation railway (Non-Patent Document 1). This device is composed of a current collecting coil that generates an induced voltage from a harmonic magnetic field and a converter that converts AC power into DC power. However, since the reactance of the current collecting coil is large, an ordinary full-wave rectifier or the like is used. A PWM converter capable of controlling the power factor to 1 (power factor 1 control) is used because sufficient power cannot be obtained.

  Further, in order to perform accurate power factor 1 control, a method (instantaneous current control method) for compensating reactive power from instantaneous current without detecting an induced voltage has been proposed and adopted (Non-patent Document 2). . In this instantaneous current control method, a converter voltage is generated from the instantaneous current so as to be equivalent to a voltage generated by a simple RC circuit, and the reactance voltage drop of the current collecting coil is compensated. Moreover, in order to supply necessary electric power to the vehicle, it is also necessary to perform output control at the same time, and while performing power factor 1 control with the reactance constant of an equivalent RC circuit, output control is performed with a resistance constant. . Furthermore, the induction current collector can generate magnetic damping that suppresses vehicle vibration by electromagnetic force generated by reactive current, and is expected to improve the riding comfort of the vehicle (Non-Patent Document 3). However, in this case, it is necessary to control to an arbitrary phase according to the vehicle vibration, and the control is also performed with the reactance constant of the equivalent RC circuit. However, since the output changes at this time, the output control system Cooperation is an important issue.

In the present invention, a control system with less interference between converter output control and phase control is proposed, and its usefulness is shown by operation simulation and the like.
Murai, Hasegawa, Fujiwara: “Improvement of Inductive Current Collection in Sidewall Levitation Method”, D. 117, 1, pp. 81-90 (1997-1) Watanabe, Ueno, Takeuchi, Nagatomi, Hayashi, Saito: “PWM converter for floating railway vehicle induction current collection by instantaneous current detection”, D. 115, 3, pp. 348-353 (1995-3) Fujiwara, Murai, Hasegawa: “Magnetic damping using current collecting coil in induction type magnetic levitation”, D. 119, 2, pp. 254-259 (1999-2) Yamamoto, Murai, Hasegawa, Shioda, Tanaka, Oyama: “Improvement of performance of PWM converter device for distributed induction current collection”, 2000 Annual Meeting of the Institute of Electrical Engineers of Japan, pp. 467-470 (2000-8)

Here, the basic principle of the inductive current collecting converter will be described.
7 is a basic configuration diagram of a conventional induction current collector (Non-Patent Document 1), FIG. 7 (a) is a schematic cross-sectional view thereof, and FIG. 7 (b) is an enlarged view of a portion A of FIG. 7 (a). It is.
In this figure, 101 is a vehicle, 102 is a carriage, 103 is a superconducting magnet cryogenic container outer tank provided on the carriage 102, 104 is a superconducting coil disposed in the superconducting magnet cryogenic container outer tank 103, and 105 is the superconducting magnet. A current collecting coil provided on the surface of the outer vessel 103 of the cryogenic vessel, 106 is a converter for power factor improvement and power control, 107 is a storage battery, 108 is an in-vehicle load, 110 is a track, and 111 is a ground coil arranged on the track 110. .

  In this way, in the superconducting magnetic levitation railway, the electromagnetic force that supports the vehicle 101 is generated by the interaction between the superconducting coil 104 and the fundamental wave component of the reaction magnetic field of the ground coil 111 generated by the movement of the superconducting coil 104. Is for collecting the harmonic component of the reaction magnetic field of the ground coil 111 by the current collecting coil 105 on the vehicle. The current collecting coil 105 constitutes a three-phase circuit in the traveling direction of the vehicle 101 and is connected to the in-vehicle load 108 via a power factor improving and power control converter (power converter) 106 and a storage battery 107. Further, since the current collecting coil 105 has a large inductance, the power factor is improved and the output is increased by using the power factor improving and power control converter 106 (PWM converter).

With such a configuration, the on-board power supply of the superconducting magnetically levitated railway is designed to inductively collect a higher speed range from the induction current collector (105, 106) and the storage battery 107 in a low speed range up to a speed of about 350 km / h. Power is supplied from the electric device (105, 106). Further, the induction current collector (105, 106) in the high speed region also charges the storage battery 107.
By the way, in the said induction current collection apparatus, while the harmonic magnetic field by the current collection coil effective current used as current collection power generates a magnetic drag, the harmonic magnetic field by the reactive current generates a vertical force. Therefore, magnetic damping that suppresses vehicle vibration can be generated by changing the power factor in accordance with the vehicle vibration speed and energizing the reactive current. In induction-type magnetic levitation, small magnetic damping is one of the issues for improving riding comfort, and the improvement of riding comfort is expected by performing magnetic damping. However, when magnetic damping is performed, there is a problem in that it interferes with the output control and adversely affects the output.

Next, the principle of the instantaneous current control method (Non-Patent Document 2) will be described.
In order to explain the principle of the instantaneous current control method, an equivalent circuit extracted for only one phase is shown in FIG. Here, the induced voltage e ₀ generated by the current collecting coil, the resistance R _s , the inductance L _s , and the angular frequency ω are the resistance R _c and the capacitor C (inductance L _c ) in the equivalent circuit of the converter. As shown in FIG. 8, in the instantaneous current control method, a converter voltage is generated so as to be equivalent to a voltage generated by a simple RC circuit, and for example, the reactance voltage drop of the collecting coil is compensated from the instantaneous current value. If the capacitor voltage is generated, power factor 1 control is achieved.

なお、上記電圧を計算するにあたっては、電流と９０度位相の異なる電圧を発生する必要があるが、３相平衡である場合、他相から容易に求められる。例えば、図９に示すように、３相回路におけるｕ相電流ｉ_u の９０度遅れ成分−ｊｉ_u は下式のように表される。

In calculating the voltage, it is necessary to generate a voltage that is 90 degrees out of phase with the current. However, in the case of three-phase equilibrium, it is easily obtained from the other phase. For example, as shown in FIG. 9, the 90-degree delay component −ji _u of the u-phase current i _u in the three-phase circuit is expressed by the following equation.

以下、同様にして、他相の９０度遅れ成分が求められ、最終的に、コンバータが発生する３相電圧は、以下のようになる。なお、実際の３相コンバータでは、ｉ_w ＝−ｉ_u −ｉ_v として、２相電流にて制御を行っている。

Hereinafter, similarly, the 90-degree delayed component of the other phase is obtained, and finally the three-phase voltage generated by the converter is as follows. In the actual 3-phase converter, as i _w = -i _u -i _v, control is performed in 2-phase current.

また、得られる集電電力Ｐは、図８の等価回路にて、

Further, the collected power P obtained is the equivalent circuit of FIG.

であり、Ｐ_max は以下のようになる。

And P _max is as follows.

なお、上記式（７）及び（８）におけるｃｏｓφは力率、ηはコンバータの効率を示す。
一方、図８の等価回路にてＬ_c ＝Ｌ_s （ｃｏｓφ＝１）に制御されるとすると、

In the above formulas (7) and (8), cos φ is the power factor, and η is the efficiency of the converter.
On the other hand, if L _c = L _s (cos φ = 1) is controlled in the equivalent circuit of FIG.

であり、その集電電力Ｐは、

The collected power P is

となる。すなわち、コンバータ等価インダクタンスＬ_c にて力率１制御して、コンバータ等価抵抗Ｒ_c にて出力制御することができる。なお、上記（７）、（８）、（１０）式は単相分であり、３相分とするには３倍すれば良い。

It becomes. That is, the power factor can be controlled by the converter equivalent inductance L _{c and the} output can be controlled by the converter equivalent resistance R _c . The above formulas (7), (8), and (10) are for a single phase, and in order to obtain a three-phase portion, it is sufficient to multiply by three.

Next, the output / phase control system is studied.
The basic control method (Non-Patent Document 4) is as follows.
In order to perform power factor 1 control, the above-described power control converter gives a converter equivalent impedance to the control constant and operates equivalently as an RC circuit (1 / jωC = −jωL _c ). Therefore, the output / phase control can be easily controlled by the equivalent impedance constant. At present, as shown in FIG. 10, the equivalent resistance R _c is actually controlled by controlling the output by the converter equivalent resistance R _c (hereinafter, equivalent resistance) and the phase by the converter equivalent inductance L _c (hereinafter, equivalent inductance). It is determined by PI control based on the difference between the output P and the output command value P _c , and the equivalent inductance L _c is determined by the current collector circuit impedance equation from the phase command value φ and the equivalent resistance R _c . When performing power factor 1 control, φ = 0.

On the other hand, when changing the phase to perform damping control, there is interference between the output control and the phase control, and the output fluctuates. As one of the countermeasures, it is necessary to design the time constant (frequency) of the output control system to be sufficiently large with respect to the phase control system in which the phase command value changes at the vehicle vibration frequency (about 5 Hz).
As described above, when superconducting linear induction current collection is performed, the reactance is large with respect to the induction voltage, and if the load is taken as it is, the voltage drop is large, so that the output cannot be secured. Therefore, a sufficient output is secured by controlling the power factor to 1 with a PWM converter. In that case, by adopting the instantaneous current method as the power factor 1 control, output control is possible by changing the resistance constant, and by changing the power factor, a reactive current flows and magnetic damping is suppressed to suppress vehicle vibration. However, when this magnetic damping is performed, there is a problem that it interferes with the output control and adversely affects the output.

  Thus, in the conventional basic method, output control and phase control interfere except when the power factor is 1. That is, the collected power P at this time is represented by the following equation, where Z is the impedance of the entire current collecting circuit.

すなわち、集電電力ＰはＲ_c ／Ｚ² に比例するが、基本方式では等価抵抗Ｒ_c の決定後、位相指令φにて等価インダクタンスＬ_c を決定するため、位相指令値φによってインピーダンスＺ、そして集電電力Ｐが変化する。例えば、位相指令φをπ／４から０に変化させるとき、インピーダンスＺは１／２^1/2 倍、集電電力は２倍となる。

That is, the collected power P is proportional to R _c / Z ² , but in the basic method, after the equivalent resistance R _c is determined, the equivalent inductance L _c is determined by the phase command φ, so that the impedance Z, Then, the collected power P changes. For example, when the phase command φ is changed from π / 4 to 0, the impedance Z is 1/2 ^1/2 times and the collected power is doubled.

  In view of the above situation, the present invention eliminates interference between output control and phase control of a conventional converter by directly controlling output using an expression proportional to the collected power, and obtains good output characteristics. An object of the present invention is to provide a converter output / phase control method capable of performing

In order to achieve the above object, the present invention provides
[1] In the converter output / phase control method, an AC side induction current collector having a current collecting coil on a vehicle for collecting harmonic components of a reaction magnetic field of a ground coil of a superconducting magnetic levitation railway, and a DC side In the converter for power control having a control system with the on-vehicle power source, the control system receives the collected power (P) and the output command value (P _C ) obtained from the induction current collector. a first adder (1), arranged in parallel with the first adder (1) output and an output obtained through the power control proportional gain (K _p) of the power control proportional gain (K _p) And the second adder (3) to which the output obtained via the integration unit (2) and the power control integral gain (K _i ) are input, the output of the second adder (3) and the the minimum gain of the control system (4R _s) and a third adder input (4), this Third adder (4) output and the phase command value φ of is inputted, the equivalent resistance R _C operation of the power control converter equivalent resistance R _C of the power control converter is output (5), power wherein the equivalent resistance R _C of the control converter phase instruction value φ is input, comprising .omega.L _C arithmetic unit for obtaining a value of the equivalent inductance L _C × omega of the power control converter and (6), as the power source the vehicle 1 / K = R _C / Z ² proportional to the DC power P (Z is the impedance of the entire current collecting circuit of the AC-side induction current collector) is directly PI controlled by DC output, and gain in the output control system The equivalent resistance R _c and the equivalent inductance L _c are determined from K, the phase command value φ, and the current collector circuit impedance formula, and the power control converter is driven by the equivalent resistance R _{c in} which variation parameters are estimated in advance. DC power It is characterized by reducing fluctuations.

[2] In the converter output / phase control method according to [1], the equivalent resistance R _c is

、等価インダクタンスＬ_c が
ωＬ_c ＝ωＬ_S ＋（Ｒ_c ＋Ｒ_S ）ｔａｎφであることを特徴とする。
ここで、ωは２πｆ、Ｒ_S は交流回路の抵抗、Ｌ_S は交流回路のインダクタンスである。

The equivalent inductance L _c is characterized by ωL _c = ωL _S + (R _c + R _S ) tanφ.
Here, ω is 2πf, R _S is the resistance of the AC circuit, and L _S is the inductance of the AC circuit.

According to the present invention, by adopting a method of calculating an equivalent resistance R _c equation that anticipates a variation parameter in advance, it is possible to reduce the variation in DC power when the converter is driven as much as possible.

An output / phase control method for a converter according to the present invention includes an inductive current collecting device on an AC side having a current collecting coil on a vehicle for collecting harmonic components of a reaction magnetic field of a ground coil of a superconducting magnetic levitation railway, and a DC side In the converter for power control having a control system with the on-vehicle power source, the control system includes a first adder to which the collected power obtained from the induction current collector and the output command value are input, An output obtained from the output of the first adder via a power control proportional gain, an integration unit arranged in parallel with the power control proportional gain, and an output obtained via the power control integral gain are input. 2, the third adder to which the output of the second adder and the minimum gain of the control system are input, the output of the third adder and the phase command value φ are input The equivalent resistance _RC of the power control converter is output. And the equivalent resistance R _C operation of the power control converters, the equivalent resistance R _C of the power control converter phase instruction value φ is input, .omega.L _C to obtain the value of the equivalent inductance L _C × omega of the power control converter 1 / K = R _C / Z ² (Z is the impedance of the entire current collecting circuit of the AC-side induction current collecting device) directly proportional to the DC power P as the on-vehicle power source and PI control by the output, the determine the equivalent resistance R _c and the equivalent inductance L _c from the gain K and the phase command value φ and the collector circuit impedance based on the output control system, the equivalent resistance R in anticipation of variation parameters in advance _{According to c} , fluctuations in DC power during driving of the power control converter are reduced.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a configuration diagram of an output / phase control method of a superconducting linear induction current collecting converter according to an embodiment of the present invention.
In FIG. 1, P is the collected power, P _c is the output command value, φ is the phase command value, K _p is the power control proportional gain, K _i is the power control integral gain, and K _min is the minimum gain (4R) of this control system. _S), 1, 3,4 adder, 2 integrator, 5 R _c is calculation unit, 6 is a .omega.L _c calculating unit.

Here, in order to reduce the interference between the output control and the phase control, a method of directly controlling the output with R _c / Z ² is used.
As shown in FIG. 1, 1 / K = R _c / Z ² proportional to the collected power P is directly PI-controlled with a DC output, and the gain K, phase command value φ, and current collection in the output control system are controlled. The equivalent resistance R _c and the equivalent inductance L _c are determined from the circuit impedance equation.

In the method of the present invention, since the collected power P is constant regardless of the phase command value φ, even if there is an influence due to the transient response, it is considered that the influence on the output control system is basically small. However, in determining R _c , a slightly complicated expression is obtained as in the following expression (13).

また、ωＬ_c 式は、ωＬ_c ＝ωＬ_S ＋（Ｒ_c ＋Ｒ_S ）ｔａｎφとなる。
以下、数値例による検討・試験を行ったので説明する。
その緒元は表１のようである。

Further, the ωL _c expression is ωL _c = ωL _S + (R _c + R _S ) tanφ.
The following is a description of examinations and tests using numerical examples.
Its specifications are shown in Table 1.

図２はシミュレーションモデルの概略ブロック図である。
１１は負荷回路、１２は電流・負荷測定回路（離散化）、１３はコンバータ電圧生成部、１４は離散化補正部、１５は誘起電圧生成部、１６は加算器、１７は集電コイル回路である。

FIG. 2 is a schematic block diagram of the simulation model.
11 is a load circuit, 12 is a current / load measurement circuit (discretization), 13 is a converter voltage generation unit, 14 is a discretization correction unit, 15 is an induced voltage generation unit, 16 is an adder, and 17 is a collecting coil circuit. is there.

For the simulation, MATLAB (SIMLINK) was used.
Conversion from three phases to two phases, calculation as two-phase alternating current, simulated discretization / discretization correction.
Here, the AC / DC converter is not simulated, but the load circuit is simulated as a transfer function.
FIG. 3 is a diagram showing an operation (simulation) at the time of phase control, FIG. 3 (a) is a characteristic diagram of a conventional basic method, FIG. 3 (b) is a characteristic diagram of the method of the present invention, and the horizontal axis represents Time (seconds), the left vertical axis indicates the angle of the phase command, and the right vertical axis indicates the power (kW). Here, the maximum current collection power of the conventional basic system is 30.6 kW (+ side fluctuation is 5.6 kW) from FIG. 3A, and the maximum current collection power of the present invention is 25.3 kW from FIG. 3B. It can be seen that (+ side fluctuation is 0.3 kW). From these, it is clear that the method of the present invention has better output characteristics of the collected power than the conventional basic method.

FIG. 4 is a schematic diagram of a test circuit.
In this figure, 21 is a PWM inverter, 22 is a transformer, 23 is a simulated current collecting coil, 24 is a PWM converter, and 25 is a load (resistance / capacitor).
5A and 5B are diagrams showing a comparison between a simulation of a conventional basic method and a test result. FIG. 5A shows the result of the simulation and FIG. 5B shows the test result. Here, the phase command is −30. The horizontal axis represents time (seconds), the left vertical axis represents the phase command angle, and the right vertical axis represents power (kW).

From these figures, it can be seen that the simulation results and the test results are almost the same.
6A and 6B are diagrams showing a comparison between the simulation of the method of the present invention and the test result. FIG. 6A shows the result of the simulation and FIG. 6B shows the test result. Here, the phase command is −30. The horizontal axis represents time (seconds), the left vertical axis represents the phase command angle, and the right vertical axis represents power (kW).

From these figures, it can be seen that the simulation results and the test results are almost the same.
In FIG. 5, the collected power greatly fluctuates to + at the same time as the converter is driven, whereas in the case of the present invention in FIG. 6, the collected power fluctuates slightly to − at the same time as the converter is driven. Thus, it can be seen that an excellent output characteristic of the collected power can be obtained.
Although the superconducting linear induction current collecting converter has been described in the above embodiment, the present invention can also be applied to a general converter as a power factor adjusting device.

  Further, the present invention is not limited to the above-described embodiments, and various modifications can be made based on the gist of the present invention, and these are not excluded from the scope of the present invention.

  The present invention is suitable as an output / phase control method for a converter.

It is a block diagram of the output and phase control system of the induction collecting converter for superconducting linear which shows the Example of this invention. It is a schematic block diagram of a simulation model. It is a figure which shows the operation | movement (simulation) at the time of phase control. It is a schematic diagram of a test circuit. It is a figure which shows the comparison with the simulation of a conventional basic system, and a test result. It is a figure which shows the comparison with the simulation of a system of this invention, and a test result. It is a basic block diagram of the conventional induction collector. It is a 1 phase equivalent circuit diagram explaining the principle of an instantaneous current control system. It is a figure which shows the relationship of each phase electric current at the time of three-phase equilibrium. It is a block diagram of the conventional basic system of output and phase control.

P Collected power P _c Output command value φ Phase command value K _p Power control proportional gain K _i Power control integral gain K _min Minimum gain of control system (4R _S )
1,3,4,16 adder 2 integrator 5 R _c calculating unit 6 .omega.L _c calculating unit 11 the load circuit 12 current-load measurement circuit (discretization)
DESCRIPTION OF SYMBOLS 13 Converter voltage generation part 14 Discretization correction | amendment part 15 Induced voltage generation part 17 Current collection coil circuit 21 PWM inverter 22 Transformer 23 Simulated current collection coil 24 PWM converter 25 Load (resistance and capacitor | condenser)

Claims (2)

A control system is provided between the AC-side induction current collector having a current-collecting coil on the vehicle that collects harmonic components of the reaction magnetic field of the ground coil of the superconducting magnetic levitation railway and the DC-side on-board power source. In the power control converter, the control system includes a first adder to which the collected power obtained from the induction current collector and an output command value are input, and a power control proportional to the output of the first adder. A second adder to which an output obtained via a gain, an integrator disposed in parallel with the power control proportional gain, and an output obtained via a power control integral gain are input; and the second adder And the third adder to which the control system minimum gain is input, the output of the third adder and the phase command value φ are input, and the equivalent resistance _RC of the power control converter is output. and the equivalent resistance R _C operation of the power control converter being, power Entered the equivalent resistance R _C of patronage converter phase command value φ is a .omega.L _C arithmetic unit for obtaining a value of the equivalent inductance L _C × omega of the power control converter, the DC power P as on the vehicle power supply Proportional 1 / K = R _C / Z ² (Z is the impedance of the entire current collecting circuit of the AC-side induction current collector) is directly PI controlled by DC output, and gain K and phase command in the output control system The equivalent resistance R _c and the equivalent inductance L _c are determined from the value φ and the current collecting circuit impedance equation , and the fluctuation of the DC power when the power control converter is driven is determined by the equivalent resistance R _c in which the fluctuation parameter is estimated in advance. A converter output / phase control method characterized by 2. The converter output / phase control method according to claim 1, wherein the equivalent resistance _Rc is

The converter output / phase control method, wherein the equivalent inductance L _c is ωL _c = ωL _S + (R _c + R _S ) tanφ.
Here, ω is 2πf, R _S is the resistance of the AC circuit, and L _S is the inductance of the AC circuit.

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